Integration Site and Clonal Expansion in Human Chronic Retroviral Infection and Gene Therapy

Science.gov (United States)

Niederer, Heather A.; Bangham, Charles R. M.

2014-01-01

Retroviral vectors have been successfully used therapeutically to restore expression of genes in a range of single-gene diseases, including several primary immunodeficiency disorders. Although clinical trials have shown remarkable results, there have also been a number of severe adverse events involving malignant outgrowth of a transformed clonal population. This clonal expansion is influenced by the integration site profile of the viral integrase, the transgene expressed, and the effect of the viral promoters on the neighbouring host genome. Infection with the pathogenic human retrovirus HTLV-1 also causes clonal expansion of cells containing an integrated HTLV-1 provirus. Although the majority of HTLV-1-infected people remain asymptomatic, up to 5% develop an aggressive T cell malignancy. In this review we discuss recent findings on the role of the genomic integration site in determining the clonality and the potential for malignant transformation of cells carrying integrated HTLV-1 or gene therapy vectors, and how these results have contributed to the understanding of HTLV-1 pathogenesis and to improvements in gene therapy vector safety. PMID:25365582

Structural dynamics of retroviral genome and the packaging.

Science.gov (United States)

Miyazaki, Yasuyuki; Miyake, Ariko; Nomaguchi, Masako; Adachi, Akio

2011-01-01

Retroviruses can cause diseases such as AIDS, leukemia, and tumors, but are also used as vectors for human gene therapy. All retroviruses, except foamy viruses, package two copies of unspliced genomic RNA into their progeny viruses. Understanding the molecular mechanisms of retroviral genome packaging will aid the design of new anti-retroviral drugs targeting the packaging process and improve the efficacy of retroviral vectors. Retroviral genomes have to be specifically recognized by the cognate nucleocapsid domain of the Gag polyprotein from among an excess of cellular and spliced viral mRNA. Extensive virological and structural studies have revealed how retroviral genomic RNA is selectively packaged into the viral particles. The genomic area responsible for the packaging is generally located in the 5' untranslated region (5' UTR), and contains dimerization site(s). Recent studies have shown that retroviral genome packaging is modulated by structural changes of RNA at the 5' UTR accompanied by the dimerization. In this review, we focus on three representative retroviruses, Moloney murine leukemia virus, human immunodeficiency virus type 1 and 2, and describe the molecular mechanism of retroviral genome packaging.

Structural dynamics of retroviral genome and the packaging

Directory of Open Access Journals (Sweden)

Yasuyuki eMiyazaki

2011-12-01

Full Text Available Retroviruses can cause diseases such as AIDS, leukemia and tumors, but are also used as vectors for human gene therapy. All retroviruses, except foamy viruses, package two copies of unspliced genomic RNA into their progeny viruses. Understanding the molecular mechanisms of retroviral genome packaging will aid the design of new anti-retroviral drugs targeting the packaging process and improve the efficacy of retroviral vectors. Retroviral genomes have to be specifically recognized by the cognate nucleocapsid (NC domain of the Gag polyprotein from among an excess of cellular and spliced viral mRNA. Extensive virological and structural studies have revealed how retroviral genomic RNA is selectively packaged into the viral particles. The genomic area responsible for the packaging is generally located in the 5’ untranslated region (5’ UTR, and contains dimerization site(s. Recent studies have shown that retroviral genome packaging is modulated by structural changes of RNA at the 5’ UTR accompanied by the dimerization. In this review, we focus on three representative retroviruses, Moloney murine leukemia virus (MoMLV, human immunodeficiency virus type 1 (HIV-1 and 2 (HIV-2, and describe the molecular mechanism of retroviral genome packaging.

Nucleic acid amplification of HIV-1 integrase sequence subtypes CRF01_AE and B for development of HIV anti-integrase drug resistance genotyping assay

Science.gov (United States)

Adlar, F. R.; Bela, B.

2017-08-01

To anticipate the potential use of anti-integrase drugs in Indonesia for treatment of HIV-1 infection, the development of a drug resistance genotyping assay for anti-integrase is crucial in identifying the genetic drug resistance profile of Indonesian HIV-1 strains. This experiment aimed to amplify a target region in the integrase gene of Indonesian HIV-1 subtypes CRF01_AE and B that contain genetic mutations known to confer resistance to anti-integrase drug. Eleven archived plasma samples from individuals living with HIV-1 were obtained from the Virology and Cancer Pathobiology Research Center for Health Service (VCPRC FKUI-RSCM) laboratory. One of the plasma samples contained HIV-1 subtype B, and the remaining plasma samples contained subtype CRF01_AE. The target regions for all samples were amplified through RT-PCR, with an annealing temperature of 55 °C, using the primer pair AE_POL 4086F and AE_POL 5232R that were designed by VCPRC FKUI-RSCM. The results of this experiment show that 18.2% (2/11) of the samples were successfully amplified using the one-step RT-PCR. While the primer pair was effective in amplifying the target region in the integrase gene sequence for subtype B (100%; 1/1), it had a low efficacy (10%, 1/10) for subtype CRF01_AE. In conclusion, the primer pair can be used to amplify the target region in Indonesian HIV-1 strain subtypes CRF01_AE and B. However, optimization of the PCR condition and an increased number of samples would help to determine an accurate representation of the efficacy of the primer pair.

Inhibition of HIV-1 Integrase gene expression by 10-23 DNAzyme

Indian Academy of Sciences (India)

We have designed three novel DNAzymes, DIN54, DIN116, and DIN152, against HIV-1 Integrase gene using Mfold software and evaluated them for target site cleavage activity on the in vitro transcribed mRNA. All DNAzymes were tested for its inhibition of expression of HIV Integrase protein in the transiently transfected cell ...

Integrase of Mason-Pfizer monkey virus

Czech Academy of Sciences Publication Activity Database

Snášel, Jan; Krejčík, Zdeněk; Jenčová, Věra; Rosenberg, Ivan; Ruml, Tomáš; Alexandratos, J.; Gustchina, A.; Pichová, Iva

2005-01-01

Roč. 272, č. 1 (2005), s. 203-216 ISSN 1742-464X R&D Projects: GA AV ČR(CZ) IAA4055304 Institutional research plan: CEZ:AV0Z4055905 Keywords : integrase * Mason-Pfizer monkey virus * HIV-1 Subject RIV: CE - Biochemistry

A method for producing transgenic cells using a multi-integrase system on a human artificial chromosome vector.

Directory of Open Access Journals (Sweden)

Shigeyuki Yamaguchi

Full Text Available The production of cells capable of expressing gene(s of interest is important for a variety of applications in biomedicine and biotechnology, including gene therapy and animal transgenesis. The ability to insert transgenes at a precise location in the genome, using site-specific recombinases such as Cre, FLP, and ΦC31, has major benefits for the efficiency of transgenesis. Recent work on integrases from ΦC31, R4, TP901-1 and Bxb1 phages demonstrated that these recombinases catalyze site-specific recombination in mammalian cells. In the present study, we examined the activities of integrases on site-specific recombination and gene expression in mammalian cells. We designed a human artificial chromosome (HAC vector containing five recombination sites (ΦC31 attP, R4 attP, TP901-1 attP, Bxb1 attP and FRT; multi-integrase HAC vector and de novo mammalian codon-optimized integrases. The multi-integrase HAC vector has several functions, including gene integration in a precise locus and avoiding genomic position effects; therefore, it was used as a platform to investigate integrase activities. Integrases carried out site-specific recombination at frequencies ranging from 39.3-96.8%. Additionally, we observed homogenous gene expression in 77.3-87.5% of colonies obtained using the multi-integrase HAC vector. This vector is also transferable to another cell line, and is capable of accepting genes of interest in this environment. These data suggest that integrases have high DNA recombination efficiencies in mammalian cells. The multi-integrase HAC vector enables us to produce transgene-expressing cells efficiently and create platform cell lines for gene expression.

New windows into retroviral RNA structures.

Science.gov (United States)

Jayaraman, Dhivya; Kenyon, Julia Claire

2018-01-25

The multiple roles of both viral and cellular RNAs have become increasingly apparent in recent years, and techniques to model them have become significantly more powerful, enabling faster and more accurate visualization of RNA structures. Techniques such as SHAPE (selective 2'OH acylation analysed by primer extension) have revolutionized the field, and have been used to examine RNAs belonging to many and diverse retroviruses. Secondary structure probing reagents such as these have been aided by the development of faster methods of analysis either via capillary or next-generation sequencing, allowing the analysis of entire genomes, and of retroviral RNA structures within virions. Techniques to model the three-dimensional structures of these large RNAs have also recently developed. The flexibility of retroviral RNAs, both structural and functional, is clear from the results of these new experimental techniques. Retroviral RNA structures and structural changes control many stages of the lifecycle, and both the RNA structures themselves and their interactions with ligands are potential new drug targets. In addition, our growing understanding of retroviral RNA structures is aiding our knowledge of cellular RNA form and function.

Raltegravir: first in class HIV integrase inhibitor

Directory of Open Access Journals (Sweden)

Zelalem Temesgen

2008-06-01

Full Text Available Zelalem Temesgen1, Dawd S Siraj21Mayo Clinic, Rochester, MN, USA; 2East Carolina University Greenville, NC, USAAbstract: On October 16, 2007, the US Food and Drug Administration (FDA approved raltegravir for treatment of human immunodeficiency virus (HIV-1 infection in combination with other antiretroviral agents in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. Raltegravir is first in a novel class of antiretroviral drugs known as integrase inhibitors. It has demonstrated potent anti HIV activity in both antiretroviral treatment-naïve and experienced patients. The most common adverse events reported with raltegravir during phase 2 and 3 clinical trials were diarrhea, nausea, and headache. Laboratory abnormalities include mild elevations in liver transaminases and creatine phosphokinase.Keywords: raltegravir, HIV, antiretroviral agents, integrase inhibitors

A historical sketch of the discovery and development of HIV-1 integrase inhibitors.

Science.gov (United States)

Savarino, Andrea

2006-12-01

The long process of HIV-1 integrase inhibitor discovery and development can be attributed to both the complexity of HIV-1 integration and poor 'integration' of these researches into mainstream investigations on antiretroviral therapy in the mid-1990s. Of note, some fungal extracts investigated during this period contain the beta-hydroxyketo group, later recognised to be a key structural requirement for keto-enol acids (also referred to as diketo acids) and other integrase inhibitors. This review reconstructs (in the general context of the history of AIDS research) the principal steps that led to the integrase inhibitors currently in clinical trials, and discusses possible future directions.

HIV-1 integrase resistance among antiretroviral treatment naive and experienced patients from Northwestern Poland

Directory of Open Access Journals (Sweden)

Parczewski Miłosz

2012-12-01

Full Text Available Abstract Background HIV integrase inhibitor use is limited by low genetic barrier to resistance and possible cross-resistance among representatives of this class of antiretrovirals. The aim of this study was to analyse integrase sequence variability among antiretroviral treatment naive and experienced patients with no prior integrase inhibitor (InI exposure and investigate development of the InI drug resistance mutations following the virologic failure of the raltegravir containing regimen. Methods Sequencing of HIV-1 integrase region from plasma samples of 80 integrase treatment naive patients and serial samples from 12 patients with observed virologic failure on raltegravir containing treatment whenever plasma vireamia exceeded >50 copies/ml was performed. Drug resistance mutations were called with Stanford DB database and grouped into major and minor variants. For subtyping bootstrapped phylogenetic analysis was used; Bayesian Monte Carlo Marcov Chain (MCMC model was implemented to infer on the phylogenetic relationships between the serial sequences from patients failing on raltegravir. Results Majority of the integrase region sequences were classified as subtype B; the remaining ones being subtype D, C, G, as well as CRF01_AE , CRF02_AG and CRF13_cpx recombinants. No major integrase drug resistance mutations have been observed in InI-treatment naive patients. In 30 (38.5% cases polymorphic variation with predominance of the E157Q mutation was observed. This mutation was more common among subtype B (26 cases, 54.2% than non-B sequences (5 cases, 16.7%, p=0.00099, OR: 5.91 (95% CI:1.77-22.63]. Other variants included L68V, L74IL, T97A, E138D, V151I, R263K. Among 12 (26.1% raltegravir treated patients treatment failure was observed; major InI drug resistance mutations (G140S, Q148H and N155H, V151I, E92EQ, V151I, G163R were noted in four of these cases (8.3% of the total InI-treated patients. Time to the development of drug resistance ranged

Amplification and chromosomal dispersion of human endogenous retroviral sequences

International Nuclear Information System (INIS)

Steele, P.E.; Martin, M.A.; Rabson, A.B.; Bryan, T.; O'Brien, S.J.

1986-01-01

Endogenous retroviral sequences have undergone amplification events involving both viral and flanking cellular sequences. The authors cloned members of an amplified family of full-length endogenous retroviral sequences. Genomic blotting, employing a flanking cellular DNA probe derived from a member of this family, revealed a similar array of reactive bands in both humans and chimpanzees, indicating that an amplification event involving retroviral and associated cellular DNA sequences occurred before the evolutionary separation of these two primates. Southern analyses of restricted somatic cell hybrid DNA preparations suggested that endogenous retroviral segments are widely dispersed in the human genome and that amplification and dispersion events may be linked

Adherence to anti-retroviral drugs in pregnant and lactating HIV ...

African Journals Online (AJOL)

Background: Anti-retroviral drugs reduce morbidity and mortality due to HIV and prevent transmission from mother to child. But compliance on anti-retroviral treatment is an essential element for the success of therapeutic goals. Objective: To assess the level of compliance of anti-retroviral treatment in pregnant and lactating ...

Small molecule inhibitors of the LEDGF site of human immunodeficiency virus integrase identified by fragment screening and structure based design.

Directory of Open Access Journals (Sweden)

Thomas S Peat

Full Text Available A fragment-based screen against human immunodeficiency virus type 1 (HIV integrase led to a number of compounds that bound to the lens epithelium derived growth factor (LEDGF binding site of the integrase catalytic core domain. We determined the crystallographic structures of complexes of the HIV integrase catalytic core domain for 10 of these compounds and quantitated the binding by surface plasmon resonance. We demonstrate that the compounds inhibit the interaction of LEDGF with HIV integrase in a proximity AlphaScreen assay, an assay for the LEDGF enhancement of HIV integrase strand transfer and in a cell based assay. The compounds identified represent a potential framework for the development of a new series of HIV integrase inhibitors that do not bind to the catalytic site of the enzyme.

Identifying Cancer Driver Genes Using Replication-Incompetent Retroviral Vectors

Directory of Open Access Journals (Sweden)

Victor M. Bii

2016-10-01

Full Text Available Identifying novel genes that drive tumor metastasis and drug resistance has significant potential to improve patient outcomes. High-throughput sequencing approaches have identified cancer genes, but distinguishing driver genes from passengers remains challenging. Insertional mutagenesis screens using replication-incompetent retroviral vectors have emerged as a powerful tool to identify cancer genes. Unlike replicating retroviruses and transposons, replication-incompetent retroviral vectors lack additional mutagenesis events that can complicate the identification of driver mutations from passenger mutations. They can also be used for almost any human cancer due to the broad tropism of the vectors. Replication-incompetent retroviral vectors have the ability to dysregulate nearby cancer genes via several mechanisms including enhancer-mediated activation of gene promoters. The integrated provirus acts as a unique molecular tag for nearby candidate driver genes which can be rapidly identified using well established methods that utilize next generation sequencing and bioinformatics programs. Recently, retroviral vector screens have been used to efficiently identify candidate driver genes in prostate, breast, liver and pancreatic cancers. Validated driver genes can be potential therapeutic targets and biomarkers. In this review, we describe the emergence of retroviral insertional mutagenesis screens using replication-incompetent retroviral vectors as a novel tool to identify cancer driver genes in different cancer types.

Anti-retroviral therapy induced diabetes in a Nigerian | Bakari ...

African Journals Online (AJOL)

African Health Sciences ... Background:Anti-retroviral therapy (ART) using Highly Active Anti-retroviral Therapy (HAART) has led to ... HIV infected individuals on one hand, and side effects of chronic administration of these drugs on the other.

Ethyl malonate amides: a diketo acid offspring fragment for HIV integrase inhibition.

Science.gov (United States)

Serafin, Katarzyna; Mazur, Pawel; Bak, Andrzej; Laine, Elodie; Tchertanov, Luba; Mouscadet, Jean-François; Polanski, Jaroslaw

2011-08-15

While searching for new HIV integrase inhibitors we discovered that some ethyl malonate amides (EMA) are active against this enzyme. Surprisingly, the main function can only very rarely be found among the reported drug candidates. We synthesised a series of compounds in order to establish and analyse the structure-activity relationship. The similarity to the important classes of HIV integrase inhibitors as well as the synthetic availability of the different targets including this pharmacophore makes EMA compounds an interesting object of investigations. Copyright © 2011 Elsevier Ltd. All rights reserved.

Lack of integrase inhibitors associated resistance mutations among HIV-1C isolates.

Science.gov (United States)

Mulu, Andargachew; Maier, Melanie; Liebert, Uwe Gerd

2015-12-01

Although biochemical analysis of HIV-1 integrase enzyme suggested the use of integrase inhibitors (INIs) against HIV-1C, different viral subtypes may favor different mutational pathways potentially leading to varying levels of drug resistance. Thus, the aim of this study was to search for the occurrence and natural evolution of integrase polymorphisms and/or resistance mutations in HIV-1C Ethiopian clinical isolates prior to the introduction of INIs. Plasma samples from chronically infected drug naïve patients (N = 45), of whom the PR and RT sequence was determined previously, were used to generate population based sequences of HIV-1 integrase. HIV-1 subtype was determined using the REGA HIV-1 subtyping tool. Resistance mutations were interpreted according to the Stanford HIV drug resistance database ( http://hivdb.stanford.edu ) and the updated International Antiviral Society (IAS)-USA mutation lists. Moreover, rates of polymorphisms in the current isolates were compared with South African and global HIV-1C isolates. All subjects were infected with HIV-1C concordant to the protease (PR) and reverse transcriptase (RT) regions. Neither major resistance-associated IN mutations (T66I/A/K, E92Q/G, T97A, Y143HCR, S147G, Q148H/R/K, and N155H) nor silent mutations known to change the genetic barrier were observed. Moreover, the DDE-catalytic motif (D64G/D116G/E152 K) and signature HHCC zinc-binding motifs at codon 12, 16, 40 and 43 were found to be highly conserved. However, compared to other South African subtype C isolates, the rate of polymorphism was variable at various positions. Although the sample size is small, the findings suggest that this drug class could be effective in Ethiopia and other southern African countries where HIV-1C is predominantly circulating. The data will contribute to define the importance of integrase polymorphism and to improve resistance interpretation algorithms in HIV-1C isolates.

Four-tiered π interaction at the dimeric interface of HIV-1 integrase critical for DNA integration and viral infectivity

International Nuclear Information System (INIS)

Al-Mawsawi, Laith Q.; Hombrouck, Anneleen; Dayam, Raveendra; Debyser, Zeger; Neamati, Nouri

2008-01-01

HIV-1 integrase (IN) is an essential enzyme for viral infection. Here, we report an extensive π electron orbital interaction between four amino acids, W132, M178, F181 and F185, located at the dimeric interface of IN that is critical for the strand transfer activity alone. Catalysis of nine different mutant IN proteins at these positions were evaluated. Whereas the 3'-processing activity is predominantly strong, the strand transfer activity of each enzyme was completely dependent on an intact π electron orbital interaction at the dimeric interface. Four representative IN mutants were constructed in the context of the infectious NL4.3 HIV-1 viral clone. Whereas viruses with an intact π electron orbital interaction at the IN dimeric interface replicated comparable to wild type, viruses containing an abolished π interaction were non-infectious. Q-PCR analysis of viral DNA forms during viral replication revealed pleiotropic effects of most mutations. We hypothesize that the π interaction is a critical contact point for the assembly of functional IN multimeric complexes, and that IN multimerization is required for a functional pre-integration complex. The rational design of small molecule inhibitors targeting the disruption of this π-π interaction should lead to powerful anti-retroviral drugs

Developing a Dynamic Pharmacophore Model for HIV-1 Integrase

International Nuclear Information System (INIS)

Carlson, Heather A.; Masukawa, Keven M.; Rubins, Kathleen; Bushman, Frederic; Jorgensen, William L.; Lins, Roberto; Briggs, James; Mccammon, Andy

2000-01-01

We present the first receptor-based pharmacophore model for HIV-1 integrase. The development of ''dynamic'' pharmacophore models is a new method that accounts for the inherent flexibility of the active site and aims to reduce the entropic penalties associated with binding a ligand. Furthermore, this new drug discovery method overcomes the limitation of an incomplete crystal structure of the target protein. A molecular dynamics (MD) simulation describes the flexibility of the uncomplexed protein. Many conformational models of the protein are saved from the MD simulations and used in a series of multi-unit search for interacting conformers (MUSIC) simulations. MUSIC is a multiple-copy minimization method, available in the BOSS program; it is used to determine binding regions for probe molecules containing functional groups that complement the active site. All protein conformations from the MD are overlaid, and conserved binding regions for the probe molecules are identified. Those conserved binding regions define the dynamic pharmacophore model. Here, the dynamic model is compared to known inhibitors of the integrase as well as a three-point, ligand-based pharmacophore model from the literature. Also, a ''static'' pharmacophore model was determined in the standard fashion, using a single crystal structure. Inhibitors thought to bind in the active site of HIV-1 integrase fit the dynamic model but not the static model. Finally, we have identified a set of compounds from the Available Chemicals Directory that fit the dynamic pharmacophore model, and experimental testing of the compounds has confirmed several new inhibitors

Tight regulation of the intS gene of the KplE1 prophage: a new paradigm for integrase gene regulation.

Directory of Open Access Journals (Sweden)

Gaël Panis

2010-10-01

Full Text Available Temperate phages have the ability to maintain their genome in their host, a process called lysogeny. For most, passive replication of the phage genome relies on integration into the host's chromosome and becoming a prophage. Prophages remain silent in the absence of stress and replicate passively within their host genome. However, when stressful conditions occur, a prophage excises itself and resumes the viral cycle. Integration and excision of phage genomes are mediated by regulated site-specific recombination catalyzed by tyrosine and serine recombinases. In the KplE1 prophage, site-specific recombination is mediated by the IntS integrase and the TorI recombination directionality factor (RDF. We previously described a sub-family of temperate phages that is characterized by an unusual organization of the recombination module. Consequently, the attL recombination region overlaps with the integrase promoter, and the integrase and RDF genes do not share a common activated promoter upon lytic induction as in the lambda prophage. In this study, we show that the intS gene is tightly regulated by its own product as well as by the TorI RDF protein. In silico analysis revealed that overlap of the attL region with the integrase promoter is widely encountered in prophages present in prokaryotic genomes, suggesting a general occurrence of negatively autoregulated integrase genes. The prediction that these integrase genes are negatively autoregulated was biologically assessed by studying the regulation of several integrase genes from two different Escherichia coli strains. Our results suggest that the majority of tRNA-associated integrase genes in prokaryotic genomes could be autoregulated and that this might be correlated with the recombination efficiency as in KplE1. The consequences of this unprecedented regulation for excessive recombination are discussed.

Magnetic concentration of a retroviral vector using magnetite cationic liposomes.

Science.gov (United States)

Ito, Akira; Takahashi, Tetsuya; Kameyama, Yujiro; Kawabe, Yoshinori; Kamihira, Masamichi

2009-03-01

For tissue engineering purposes, retroviral vectors represent an efficient method of delivering exogenous genes such as growth factors to injured tissues because gene-transduced cells can produce stable and constant levels of the gene product. However, retroviral vector technology suffers from low yields. In the present study, we used magnetite nanoparticles and magnetic force to concentrate the retroviral vectors to enhance the transduction efficiency and to enable their magnetic manipulation. Magnetite nanoparticles modified with cationic liposomes were added to a solution containing a retroviral vector pseudotyped with vesicular stomatitis virus glycoprotein. The magnetic particles that captured the viral vectors were collected using a magnetic force and seeded into mouse neuroblastoma Neuro2a cells. The viral titer was up to 55 times greater (up to 3 x 10(8) infectious units/mL). Additionally, the magnetically labeled retroviral vectors can be directed to the desired regions for infection by applying magnetic fields, and micro-patterns of gene-transduced cell regions could be created on a cellular monolayer using micro-patterned magnetic concentrators. These results suggest that this technique provides a promising approach to capturing and concentrating viral vectors, thus achieving high transduction efficiency and the ability to deliver genes to a specific injured site by applying a magnetic field.

In vivo and in vitro characterization of site-specific recombination of a novel serine integrase from the temperate phage EFC-1

Energy Technology Data Exchange (ETDEWEB)

Yoon, Bohyun; Kim, Inki; Nam, Ja-Ae [Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan, 86 Asanbyeoungwon-gil, Songpa-gu, Seoul 138-736 (Korea, Republic of); Chang, Hyo-Ihl [College of Life Sciences & Biotechnology, Korea University, 5-1 Anam-dong, Seongbuk-gu, Seoul 136-701 (Korea, Republic of); Ha, Chang Hoon, E-mail: chhoonha@amc.seoul.kr [Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan, 86 Asanbyeoungwon-gil, Songpa-gu, Seoul 138-736 (Korea, Republic of)

2016-04-22

EFC-1 integrase is a site-specific recombinase that belongs to the large family of serine recombinase. In previously study, we isolated the temperate phage EFC-1, and characterized its genomic sequence. Within its genome, Orf28 was predicted encode a 464 amino acid of a putative integrase gene. In this study, EFC-1 integrase was characterized in vitro and in vivo. In vitro assay was performed using purified His-tag fusion integrase. Also, to identify which serine is involved in the catalytic domain, we used site-directed mutagenesis and analyzed by a recombination assay in vitro. In vivo assay involved PCR and confocal microscopy in HEK293 cells, and determined the minimal lengths of attP and attB sites. According to our results, the EFC-1 integrase-mediated recombination was site-specific and unidirectional system in vitro and in vivo. Serine 21 of EFC-1 integrase plays a major role in the catalytic domain, and minimal sizes of attB and attP was defined 48 and 54 bp. Our finding may help develop a useful tool for gene therapy and gene delivery system. - Highlights: • EFC-1 integrase-mediated recombination was site-specific and unidirectional system. • Serine 21 of EFC-1 integrase plays a major role in the catalytic domain. • The functional minimal sizes of attB and attP was defined 48 and 54 bp.

In vivo and in vitro characterization of site-specific recombination of a novel serine integrase from the temperate phage EFC-1

International Nuclear Information System (INIS)

Yoon, Bohyun; Kim, Inki; Nam, Ja-Ae; Chang, Hyo-Ihl; Ha, Chang Hoon

2016-01-01

EFC-1 integrase is a site-specific recombinase that belongs to the large family of serine recombinase. In previously study, we isolated the temperate phage EFC-1, and characterized its genomic sequence. Within its genome, Orf28 was predicted encode a 464 amino acid of a putative integrase gene. In this study, EFC-1 integrase was characterized in vitro and in vivo. In vitro assay was performed using purified His-tag fusion integrase. Also, to identify which serine is involved in the catalytic domain, we used site-directed mutagenesis and analyzed by a recombination assay in vitro. In vivo assay involved PCR and confocal microscopy in HEK293 cells, and determined the minimal lengths of attP and attB sites. According to our results, the EFC-1 integrase-mediated recombination was site-specific and unidirectional system in vitro and in vivo. Serine 21 of EFC-1 integrase plays a major role in the catalytic domain, and minimal sizes of attB and attP was defined 48 and 54 bp. Our finding may help develop a useful tool for gene therapy and gene delivery system. - Highlights: • EFC-1 integrase-mediated recombination was site-specific and unidirectional system. • Serine 21 of EFC-1 integrase plays a major role in the catalytic domain. • The functional minimal sizes of attB and attP was defined 48 and 54 bp.

Nanobody-based chimeric receptor gene integration in Jurkat cells mediated by PhiC31 integrase

International Nuclear Information System (INIS)

Iri-Sofla, Farnoush Jafari; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud; Rasaee, Mohammad J.

2011-01-01

The crucial role of T lymphocytes in anti-tumor immunity has led to the development of novel strategies that can target and activate T cells against tumor cells. Recombinant DNA technology has been used to generate non-MHC-restricted chimeric antigen receptors (CARs). Here, we constructed a panel of recombinant CAR that harbors the anti-MUC1 nanobody and the signaling and co-signaling moieties (CD3ζ/CD28) with different spacer regions derived from human IgG3 with one or two repeats of the hinge sequence or the hinge region of FcγRII. The PhiC31 integrase system was employed to investigate if the recombination efficiency could be recruited for high and stable expression of T cell chimeric receptor genes. The effect of nuclear localization signal (NLS) and two different promoters (CMV and CAG) on efficacy of PhiC31 integrase in human T cell lines was evaluated. The presence of integrase in combination with NLS, mediated up to 7.6 and 8.5 fold increases in CAR expression in ZCHN-attB and ZCHHN-attB cassette integrated T cells, respectively. Our results showed that highly efficient and stable transduction of the Jurkat cell line by PhiC31 integrase is a feasible modality for generating anti-cancer chimeric T cells for use in cancer immunotherapy.

Nanobody-based chimeric receptor gene integration in Jurkat cells mediated by PhiC31 integrase

Energy Technology Data Exchange (ETDEWEB)

Iri-Sofla, Farnoush Jafari [Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Rahbarizadeh, Fatemeh, E-mail: rahbarif@modares.ac.ir [Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Ahmadvand, Davoud [Center of Pharmaceutical Nanotechnology and Nanotoxicology, Department of Pharmaceutics and Analytical Chemistry, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen O (Denmark); Rasaee, Mohammad J. [Department of Medical Biotechnology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2011-11-01

The crucial role of T lymphocytes in anti-tumor immunity has led to the development of novel strategies that can target and activate T cells against tumor cells. Recombinant DNA technology has been used to generate non-MHC-restricted chimeric antigen receptors (CARs). Here, we constructed a panel of recombinant CAR that harbors the anti-MUC1 nanobody and the signaling and co-signaling moieties (CD3{zeta}/CD28) with different spacer regions derived from human IgG3 with one or two repeats of the hinge sequence or the hinge region of Fc{gamma}RII. The PhiC31 integrase system was employed to investigate if the recombination efficiency could be recruited for high and stable expression of T cell chimeric receptor genes. The effect of nuclear localization signal (NLS) and two different promoters (CMV and CAG) on efficacy of PhiC31 integrase in human T cell lines was evaluated. The presence of integrase in combination with NLS, mediated up to 7.6 and 8.5 fold increases in CAR expression in ZCHN-attB and ZCHHN-attB cassette integrated T cells, respectively. Our results showed that highly efficient and stable transduction of the Jurkat cell line by PhiC31 integrase is a feasible modality for generating anti-cancer chimeric T cells for use in cancer immunotherapy.

Improved Coinfection with Amphotropic Pseudotyped Retroviral Vectors

Directory of Open Access Journals (Sweden)

Yuehong Wu

2009-01-01

Full Text Available Amphotropic pseudotyped retroviral vectors have typically been used to infect target cells without prior concentration. Although this can yield high rates of infection, higher rates may be needed where highly efficient coinfection of two or more vectors is needed. In this investigation we used amphotropic retroviral vectors produced by the Plat-A cell line and studied coinfection rates using green and red fluorescent proteins (EGFP and dsRed2. Target cells were primary human fibroblasts (PHF and 3T3 cells. Unconcentrated vector preparations produced a coinfection rate of ∼4% (defined as cells that are both red and green as a percentage of all cells infected. Optimized spinoculation, comprising centrifugation at 1200 g for 2 hours at 15∘C, increased the coinfection rate to ∼10%. Concentration by centrifugation at 10,000 g or by flocculation using Polybrene increased the coinfection rate to ∼25%. Combining the two processes, concentration by Polybrene flocculation and optimized spinoculation, increased the coinfection rate to 35% (3T3 or >50% (PHF. Improved coinfection should be valuable in protocols that require high transduction by combinations of two or more retroviral vectors.

[Isolation, idetification and anti-HIV-1 integrase activity of culturable endophytic fungi from Tibetan medicinal plant Phlomis younghusbandii Mukerjee].

Science.gov (United States)

Zhang, Da-Wei; Zhao, Ming-Ming; Chen, Juan; Li, Chao; Guo, Shun-Xing

2013-05-01

A total of 52 endophytic fungi were isolated from roots and stems of Tibetan medicinal plant Phlomis younghusbandii Mukerjee. These fungal isolates were molecularly identified based on ITS sequnces and 28S sequences distributed to 12 genera, including Phoma, Chaetosphaeronema, Fusarium and Leptosphaeria, etc. Among them, the dominant genus was Phoma. Extracts of all strains were evaluated for anti-HIV-1 integrase activity by using soluable integrase expressed in E. coli BL21 (DE3). The results showed that seven samples from five fungal endophytes PHY-24, PHY-38, PHY-40, PHY-51, PHY-53, which belonged to genus Chaetosphaeronema, inhibited strand transfer reaction catalyzed by HIV-1 integrase with IC50 values, of 6.60, 5.20, 2.86, 7.86, 4.47, 4.56 and 3.23 microg x mL(-1) respectively. In conclusion, the endophytic fungi of Phlomis younghusbandii Mukerjee are valuable for further screening anti-HIV-1 integrase agents.

Retroviral Vectors: Post Entry Events and Genomic Alterations

Directory of Open Access Journals (Sweden)

Christof von Kalle

2011-04-01

Full Text Available The curative potential of retroviral vectors for somatic gene therapy has been demonstrated impressively in several clinical trials leading to sustained long-term correction of the underlying genetic defect. Preclinical studies and clinical monitoring of gene modified hematopoietic stem and progenitor cells in patients have shown that biologically relevant vector induced side effects, ranging from in vitro immortalization to clonal dominance and oncogenesis in vivo, accompany therapeutic efficiency of integrating retroviral gene transfer systems. Most importantly, it has been demonstrated that the genotoxic potential is not identical among all retroviral vector systems designed for clinical application. Large scale viral integration site determination has uncovered significant differences in the target site selection of retrovirus subfamilies influencing the propensity for inducing genetic alterations in the host genome. In this review we will summarize recent insights gained on the mechanisms of insertional mutagenesis based on intrinsic target site selection of different retrovirus families. We will also discuss examples of side effects occurring in ongoing human gene therapy trials and future prospectives in the field.

Impact of hydrodynamic injection and phiC31 integrase on tumor latency in a mouse model of MYC-induced hepatocellular carcinoma.

Directory of Open Access Journals (Sweden)

Lauren E Woodard

2010-06-01

Full Text Available Hydrodynamic injection is an effective method for DNA delivery in mouse liver and is being translated to larger animals for possible clinical use. Similarly, phiC31 integrase has proven effective in mediating long-term gene therapy in mice when delivered by hydrodynamic injection and is being considered for clinical gene therapy applications. However, chromosomal aberrations have been associated with phiC31 integrase expression in tissue culture, leading to questions about safety.To study whether hydrodynamic delivery alone, or in conjunction with delivery of phiC31 integrase for long-term transgene expression, could facilitate tumor formation, we used a transgenic mouse model in which sustained induction of the human C-MYC oncogene in the liver was followed by hydrodynamic injection. Without injection, mice had a median tumor latency of 154 days. With hydrodynamic injection of saline alone, the median tumor latency was significantly reduced, to 105 days. The median tumor latency was similar, 106 days, when a luciferase donor plasmid and backbone plasmid without integrase were administered. In contrast, when active or inactive phiC31 integrase and donor plasmid were supplied to the mouse liver, the median tumor latency was 153 days, similar to mice receiving no injection.Our data suggest that phiC31 integrase does not facilitate tumor formation in this C-MYC transgenic mouse model. However, in groups lacking phiC31 integrase, hydrodynamic injection appeared to contribute to C-MYC-induced hepatocellular carcinoma in adult mice. Although it remains to be seen to what extent these findings may be extrapolated to catheter-mediated hydrodynamic delivery in larger species, they suggest that caution should be used during translation of hydrodynamic injection to clinical applications.

Novel Bifunctional Quinolonyl Diketo Acid Derivatives as HIV-1 Integrase Inhibitors: Design, Synthesis, Biological Activities and Mechanism of Action

Science.gov (United States)

Di Santo, Roberto; Costi, Roberta; Roux, Alessandra; Artico, Marino; Lavecchia, Antonio; Marinelli, Luciana; Novellino, Ettore; Palmisano, Lucia; Andreotti, Mauro; Amici, Roberta; Galluzzo, Clementina Maria; Nencioni, Lucia; Palamara, Anna Teresa; Pommier, Yves; Marchand, Christophe

2008-01-01

The virally encoded integrase protein is an essential enzyme in the life cycle of the HIV-1 virus and represents an attractive and validated target in the development of therapeutics against HIV infection. Drugs that selectively inhibit this enzyme, when used in combination with inhibitors of reverse transcriptase and protease, are believed to be highly effective in suppressing the viral replication. Among the HIV-1 integrase inhibitors, the β-diketo acids (DKAs) represent a major lead for anti-HIV-1drug development. In this study, novel bifunctional quinolonyl diketo acid derivatives were designed, synthesized and tested for their inhibitory ability against HIV-1 integrase. The compounds are potent inhibitors of integrase activity. Particularly, derivative 8 is a potent IN inhibitor for both steps of the reaction (3′-processing and strand transfer) and exhibits both high antiviral activity against HIV-1 infected cells and low cytotoxicity. Molecular modeling studies provide a plausible mechanism of action, which is consistent with ligand SARs and enzyme photo-crosslinking experiments. PMID:16539381

Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

Directory of Open Access Journals (Sweden)

Ranyee A Chiang

2008-08-01

Full Text Available The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized

Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

Science.gov (United States)

Chiang, Ranyee A; Sali, Andrej; Babbitt, Patricia C

2008-08-01

The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized and uncharacterized

Efficient site-specific integration in Plasmodium falciparum chromosomes mediated by mycobacteriophage Bxb1 integrase.

Science.gov (United States)

Nkrumah, Louis J; Muhle, Rebecca A; Moura, Pedro A; Ghosh, Pallavi; Hatfull, Graham F; Jacobs, William R; Fidock, David A

2006-08-01

Here we report an efficient, site-specific system of genetic integration into Plasmodium falciparum malaria parasite chromosomes. This is mediated by mycobacteriophage Bxb1 integrase, which catalyzes recombination between an incoming attP and a chromosomal attB site. We developed P. falciparum lines with the attB site integrated into the glutaredoxin-like cg6 gene. Transfection of these attB(+) lines with a dual-plasmid system, expressing a transgene on an attP-containing plasmid together with a drug resistance gene and the integrase on a separate plasmid, produced recombinant parasites within 2 to 4 weeks that were genetically uniform for single-copy plasmid integration. Integrase-mediated recombination resulted in proper targeting of parasite proteins to intra-erythrocytic compartments, including the apicoplast, a plastid-like organelle. Recombinant attB x attP parasites were genetically stable in the absence of drug and were phenotypically homogeneous. This system can be exploited for rapid genetic integration and complementation analyses at any stage of the P. falciparum life cycle, and it illustrates the utility of Bxb1-based integrative recombination for genetic studies of intracellular eukaryotic organisms.

Development of a novel in vitro assay for the evaluation of integron DNA integrase activity

Directory of Open Access Journals (Sweden)

Fatemeh Tohidi

2016-05-01

Full Text Available Integrons play an important role in multidrug resistance. The integron platform codes for integrase (intI that is required for gene cassette integration through site-specific recombination. The recombination crossover occurs between the G and TT nucleotides in non-palindromic attI and palindromic attC sites. The aim of this study was to establish an efficient in vitro assay for integrase purification and activity detection. To this end, the intI gene was cloned into the pET-22b plasmid. Then, the resulting recombinant plasmid was transformed into Escherichia coli Origami™ strain. The recombinant protein expression was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE and western blot assays. The recombinant intI protein was purified by nickel–nitrilotriacetic acid (Ni–NTA affinity chromatography, and its activity was measured by a newly introduced assay. Briefly, specific primers for each side of attI and attC were used, thereby, a polymerase chain reaction would be performed, if a fused plasmid containing both attI and attC sites was created upon recombination. SDS-PAGE and western blotting confirmed the presence of a 38-kDa recombinant protein. Optimum conditions were established for the measurement of the integrase activity and a new model assay was conducted to analyse the recombination activity in vitro. Although the electrophoretic mobility shift assay is an efficient and reliable method, the newly introduced assay provided new or enhanced capability to determine the integrase activity, suggesting that there is no need for expensive and advanced equipment.

Follistatin allows efficient retroviral-mediated gene transfer into rat liver

International Nuclear Information System (INIS)

Borgnon, Josephine; Djamouri, Fatima; Lorand, Isabelle; Rico, Virginie Di; Loux, Nathalie; Pages, Jean-Christophe; Franco, Dominique; Capron, Frederique; Weber, Anne

2005-01-01

Retroviral vectors are widely used tools for gene therapy. However, in vivo gene transfer is only effective in dividing cells, which, in liver, requires a regenerative stimulus. Follistatin is effective in promoting liver regeneration after 90% and 70% hepatectomy in rats. We studied its efficacy on liver regeneration and retroviral-mediated gene delivery in 50% hepatectomized rats. When human recombinant follistatin was infused into the portal vein immediately after 50% hepatectomy, hepatocyte proliferation was significantly higher than in control 50% hepatectomized rats. A single injection of virus particles administered 23 h after follistatin infusion resulted in more than 20% gene transduction efficiency in hepatocytes compared to 3% in control rats. It is concluded that a single injection of follistatin induces onset of proliferation in 50% hepatectomized rats and allows efficient retroviral-mediated gene transfer to the liver

Postexposure protection of macaques from vaginal SHIV infection by topical integrase inhibitors.

Science.gov (United States)

Dobard, Charles; Sharma, Sunita; Parikh, Urvi M; West, Rolieria; Taylor, Andrew; Martin, Amy; Pau, Chou-Pong; Hanson, Debra L; Lipscomb, Jonathan; Smith, James; Novembre, Francis; Hazuda, Daria; Garcia-Lerma, J Gerardo; Heneine, Walid

2014-03-12

Coitally delivered microbicide gels containing antiretroviral drugs are important for HIV prevention. However, to date, microbicides have contained entry or reverse transcriptase inhibitors that block early steps in virus infection and thus need to be given as a preexposure dose that interferes with sexual practices and may limit compliance. Integrase inhibitors block late steps after virus infection and therefore are more suitable for post-coital dosing. We first determined the kinetics of strand transfer in vitro and confirmed that integration begins about 6 hours after infection. We then used a repeat-challenge macaque model to assess efficacy of vaginal gels containing integrase strand transfer inhibitors when applied before or after simian/human immunodeficiency virus (SHIV) challenge. We showed that gel containing the strand transfer inhibitor L-870812 protected two of three macaques when applied 30 min before SHIV challenge. We next evaluated the efficacy of 1% raltegravir gel and demonstrated its ability to protect macaques when applied 3 hours after SHIV exposure (five of six protected; P infections showed no evidence of drug resistance in plasma or vaginal secretions despite continued gel dosing after infection. We documented rapid vaginal absorption reflecting a short pharmacological lag time and noted that vaginal, but not plasma, virus load was substantially reduced in the breakthrough infection after raltegravir gel treatment. We provide a proof of concept that topically applied integrase inhibitors protect against vaginal SHIV infection when administered shortly before or 3 hours after virus exposure.

Acute retroviral syndrome in Slovenian patients infected with HIV

Directory of Open Access Journals (Sweden)

Mateja Pirš

2005-06-01

Full Text Available Background: Two to six weeks after primary infection with HIV 50 to 90 percent of patients develop an acute retroviral syndrome which usually presents with mononucleosis or flu-like illness. Due to nonspecific symptoms ARS is frequently misdiagnosed.Patients and methods: Data of Slovenian patients with acute retroviral syndrome is shown, as well as their symptoms, approaches to management and diagnostic particularities of primary HIV infection.Conclusions: The combination of particular symptoms and epidemiological data should lead us to consider the possibility of an early HIV infection.

Sketching the historical development of pyrimidones as the inhibitors of the HIV integrase

Czech Academy of Sciences Publication Activity Database

Patel, Rahul V.; Keum, Y.S.; Park, S.W.

2015-01-01

Roč. 97, JUN 5 (2015), s. 649-663 ISSN 0223-5234 Institutional support: RVO:61389030 Keywords : Pyrimidones * Anti-HIV * Integrase inhibitors Subject RIV: CE - Biochemistry Impact factor: 3.902, year: 2015

Construction of retroviral recombinant containing human tissue ...

African Journals Online (AJOL)

USER

2010-03-29

Mar 29, 2010 ... Recombinant retroviral vector containing human tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) gene was ..... heavy metal ions, the protein could be express in an .... involves adhesion, degradation and movement. To.

The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome

NARCIS (Netherlands)

van Bel, Nikki; van der Velden, Yme; Bonnard, Damien; Le Rouzic, Erwann; Das, Atze T.; Benarous, Richard; Berkhout, Ben

2014-01-01

The viral integrase (IN) is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs). Although designed to

Main trends of karyotype evolution in the superfamily Chalcidoidea (Hymenoptera

Directory of Open Access Journals (Sweden)

Vladimir Gokhman

2009-08-01

Full Text Available An overview of karyotype evolution in the superfamily Chalcidoidea is given. Structural types of chromosome sets in the superfamily are listed. Main pathways of karyotypic change in the Chalcidoidea are outlined. The chromosome set containing eleven subtelo- or acrocentrics is considered as an ancestral karyotype for the superfamily. Multiple independent reductions in n values through chromosomal fusions presumably occurred in various groups of chalcid families.

Comparison Between Several Integrase-defective Lentiviral Vectors Reveals Increased Integration of an HIV Vector Bearing a D167H Mutant

Directory of Open Access Journals (Sweden)

Muhammad Qamar Saeed

2014-01-01

Full Text Available HIV-1 derived vectors are among the most efficient for gene transduction in mammalian tissues. As the parent virus, they carry out vector genome insertion into the host cell chromatin. Consequently, their preferential integration in transcribed genes raises several conceptual and safety issues. To address part of these questions, HIV-derived vectors have been engineered to be nonintegrating. This was mainly achieved by mutating HIV-1 integrase at functional hotspots of the enzyme enabling the development of streamlined nuclear DNA circles functional for transgene expression. Few integrase mutant vectors have been successfully tested so far for gene transfer. They are cleared with time in mitotic cells, but stable within nondividing retina cells or neurons. Here, we compared six HIV vectors carrying different integrases, either wild type or with different mutations (D64V, D167H, Q168A, K186Q+Q214L+Q216L, and RRK262-264AAH shown to modify integrase enzymatic activity, oligomerization, or interaction with key cellular cofactor of HIV DNA integration as LEDGF/p75 or TNPO3. We show that these mutations differently affect the transduction efficiency as well as rates and patterns of integration of HIV-derived vectors suggesting their different processing in the nucleus. Surprisingly and most interestingly, we report that an integrase carrying the D167H substitution improves vector transduction efficiency and integration in both HEK-293T and primary CD34+ cells.

Phylogenomic analysis of the GIY-YIG nuclease superfamily

Directory of Open Access Journals (Sweden)

Bujnicki Janusz M

2006-04-01

Full Text Available Abstract Background The GIY-YIG domain was initially identified in homing endonucleases and later in other selfish mobile genetic elements (including restriction enzymes and non-LTR retrotransposons and in enzymes involved in DNA repair and recombination. However, to date no systematic search for novel members of the GIY-YIG superfamily or comparative analysis of these enzymes has been reported. Results We carried out database searches to identify all members of known GIY-YIG nuclease families. Multiple sequence alignments together with predicted secondary structures of identified families were represented as Hidden Markov Models (HMM and compared by the HHsearch method to the uncharacterized protein families gathered in the COG, KOG, and PFAM databases. This analysis allowed for extending the GIY-YIG superfamily to include members of COG3680 and a number of proteins not classified in COGs and to predict that these proteins may function as nucleases, potentially involved in DNA recombination and/or repair. Finally, all old and new members of the GIY-YIG superfamily were compared and analyzed to infer the phylogenetic tree. Conclusion An evolutionary classification of the GIY-YIG superfamily is presented for the very first time, along with the structural annotation of all (subfamilies. It provides a comprehensive picture of sequence-structure-function relationships in this superfamily of nucleases, which will help to design experiments to study the mechanism of action of known members (especially the uncharacterized ones and will facilitate the prediction of function for the newly discovered ones.

Two different groups of signal sequence in M-superfamily conotoxins.

Science.gov (United States)

Wang, Qi; Jiang, Hui; Han, Yu-Hong; Yuan, Duo-Duo; Chi, Cheng-Wu

2008-04-01

M-superfamily conotoxins can be divided into four branches (M-1, M-2, M-3 and M-4) according to the number of amino acid residues in the third Cys loop. In general, it is widely accepted that the conotoxin signal peptides of each superfamily are strictly conserved. Recently, we cloned six cDNAs of novel M-superfamily conotoxins from Conus leopardus, Conus marmoreus and Conus quercinus, belonging to either M-1 or M-3 branch. These conotoxins, judging from the putative peptide sequences deducted from cDNAs, are rich in acidic residues and share highly conserved signal and pro-peptide region. However, they are quite different from the reported conotoxins of M-2 and M-4 branches even in their signal peptides, which in general are considered highly conserved for each superfamily of conotoxins. The signal sequences of M-1 and M-3 conotoxins composed of 24 residues start with MLKMGVVL-, while those of M-2 and M-4 conotoxins composed of 25 residues start with MMSKLGVL-. It is another example that different types of signal peptides can exist within a superfamily besides the I-conotoxin superfamily. In addition to the different disulfide connectivity of M-1 conotoxins from that of M-4 or M-2 conotoxins, the sequence alignment, preferential Cys codon usage and phylogenetic tree analysis suggest that M-1 and M-3 conotoxins have much closer relationship, being different from the conotoxins of other two branches (M-4 and M-2) of M-superfamily.

Molecular features related to HIV integrase inhibition obtained from structure- and ligand-based approaches.

Directory of Open Access Journals (Sweden)

Luciana L de Carvalho

Full Text Available Among several biological targets to treat AIDS, HIV integrase is a promising enzyme that can be employed to develop new anti-HIV agents. The aim of this work is to propose a mechanistic interpretation of HIV-1 integrase inhibition and to rationalize the molecular features related to the binding affinity of studied ligands. A set of 79 HIV-1 integrase inhibitors and its relationship with biological activity are investigated employing 2D and 3D QSAR models, docking analysis and DFT studies. Analyses of docking poses and frontier molecular orbitals revealed important features on the main ligand-receptor interactions. 2D and 3D models presenting good internal consistency, predictive power and stability were obtained in all cases. Significant correlation coefficients (r(2 = 0.908 and q(2= 0.643 for 2D model; r(2= 0.904 and q(2= 0.719 for 3D model were obtained, indicating the potential of these models for untested compounds. The generated holograms and contribution maps revealed important molecular requirements to HIV-1 IN inhibition and several evidences for molecular modifications. The final models along with information resulting from molecular orbitals, 2D contribution and 3D contour maps should be useful in the design of new inhibitors with increased potency and selectivity within the chemical diversity of the data.

Detection of a human intracisternal A-type retroviral particle antigenically related to HIV

Science.gov (United States)

Garry, R. F.; Fermin, C. D.; Hart, D. J.; Alexander, S. S.; Donehower, L. A.; Luo-Zhang, H.

1990-01-01

Sjogren's syndrome is an autoimmune disease that is characterized by dryness of the mouth and eyes. The loss of salivary and lacrimal gland function is accompanied by lymphocytic infiltration. Because similar symptoms and glandular pathology are observed in certain persons infected with human immunodeficiency virus (HIV), a search was initiated for a possible retroviral etiology in this syndrome. A human intracisternal A-type retroviral particle that is antigenically related to HIV was detected in lymphoblastoid cells exposed to homogenates of salivary tissue from patients with Sjogren's syndrome. Comparison of this retroviral particle to HIV indicates that they are distinguishable by several ultrastructural, physical, and enzymatic criteria.

Functional cloning using pFB retroviral cDNA expression libraries.

Science.gov (United States)

Felts, Katherine A; Chen, Keith; Zaharee, Kim; Sundar, Latha; Limjoco, Jamie; Miller, Anna; Vaillancourt, Peter

2002-09-01

Retroviral cDNA expression libraries allow the efficient introduction of complex cDNA libraries into virtually any mitotic cell type for screening based on gene function. The cDNA copy number per cell can be easily controlled by adjusting the multiplicity of infection, thus cell populations may be generated in which >90% of infected cells contain one to three cDNAs. We describe the isolation of two known oncogenes and one cell-surface receptor from a human Burkitt's lymphoma (Daudi) cDNA library inserted into the high-titer retroviral vector pFB.

MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals.

Science.gov (United States)

Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

2016-02-12

SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we describe 15 SINEs, among which 13 are novel, that have a similar 66-bp central region and therefore constitute a new SINE superfamily, MetaSINEs. MetaSINEs are distributed from fish to cnidarians, suggesting their common evolutionary origin at least 640 Ma. Because the 3' tails of MetaSINEs are variable, these SINEs most likely survived by changing their partner long interspersed elements for retrotransposition during evolution. Furthermore, we examined the presence of members of other SINE superfamilies in bivalve genomes and characterized eight new SINEs belonging to the CORE-SINEs, V-SINEs, and DeuSINEs, in addition to the MetaSINEs. The broad distribution of bivalve SINEs suggests that at least three SINEs originated in the common ancestor of Bivalvia. Our comparative analysis of the central domains of the SINEs revealed that, in each superfamily, only a restricted region is shared among all of its members. Because the functions of the central domains of the SINE superfamilies remain unknown, such structural information of SINE superfamilies will be useful for future experimental and comparative analyses to reveal why they have been retained in metazoan genomes during evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The aldo-keto reductase superfamily homepage.

Science.gov (United States)

Hyndman, David; Bauman, David R; Heredia, Vladi V; Penning, Trevor M

2003-02-01

The aldo-keto reductases (AKRs) are one of the three enzyme superfamilies that perform oxidoreduction on a wide variety of natural and foreign substrates. A systematic nomenclature for the AKR superfamily was adopted in 1996 and was updated in September 2000 (visit www.med.upenn.edu/akr). Investigators have been diligent in submitting sequences of functional proteins to the Web site. With the new additions, the superfamily contains 114 proteins expressed in prokaryotes and eukaryotes that are distributed over 14 families (AKR1-AKR14). The AKR1 family contains the aldose reductases, the aldehyde reductases, the hydroxysteroid dehydrogenases and steroid 5beta-reductases, and is the largest. Other families of interest include AKR6, which includes potassium channel beta-subunits, and AKR7 the aflatoxin aldehyde reductases. Two new families include AKR13 (yeast aldose reductase) and AKR14 (Escherichia coli aldehyde reductase). Crystal structures of many AKRs and their complexes with ligands are available in the PDB and accessible through the Web site. Each structure has the characteristic (alpha/beta)(8)-barrel motif of the superfamily, a conserved cofactor binding site and a catalytic tetrad, and variable loop structures that define substrate specificity. Although the majority of AKRs are monomeric proteins of about 320 amino acids in length, the AKR2, AKR6 and AKR7 family may form multimers. To expand the nomenclature to accommodate multimers, we recommend that the composition and stoichiometry be listed. For example, AKR7A1:AKR7A4 (1:3) would designate a tetramer of the composition indicated. The current nomenclature is recognized by the Human Genome Project (HUGO) and the Web site provides a link to genomic information including chromosomal localization, gene boundaries, human ESTs and SNPs and much more.

Chromosomal locations of members of a family of novel endogenous human retroviral genomes

International Nuclear Information System (INIS)

Horn, T.M.; Huebner, K.; Croce, C.; Callahan, R.

1986-01-01

Human cellular DNA contains two distinguishable families of retroviral related sequences. One family shares extensive nucleotide sequence homology with infectious mammalian type C retroviral genomes. The other family contains major regions of homology with the pol genes of infectious type A and B and avian type C and D retroviral genomes. Analysis of the human recombinant clone HLM-2 has shown that the pol gene in the latter family is located within an endogenous proviral genome. The authors show that the proviral genome in HLM-2 and the related recombinant clone HLM-25 are located, respectively, on human chromosomes 1 and 5. Other related proviral genomes are located on chromosomes 7, 8, 11, 14, and 17

Cancer-specific binary expression system activated in mice by bacteriophage HK022 Integrase

DEFF Research Database (Denmark)

Elias, Amer; Spector, Itay; Sogolovsky-Bard, Ilana

2016-01-01

Binary systems based on site-specific recombination have been used for tumor specific transcription targeting of suicide genes in animal models. In these binary systems a site specific recombinase or integrase that is expressed from a tumor specific promoter drives tumor specific expression of a ...

MetaSINEs: Broad Distribution of a Novel SINE Superfamily in Animals

OpenAIRE

Nishihara, Hidenori; Plazzi, Federico; Passamonti, Marco; Okada, Norihiro

2016-01-01

SINEs (short interspersed elements) are transposable elements that typically originate independently in each taxonomic clade (order/family). However, some SINE families share a highly similar central sequence and are thus categorized as a SINE superfamily. Although only four SINE superfamilies (CORE-SINEs, V-SINEs, DeuSINEs, and Ceph-SINEs) have been reported so far, it is expected that new SINE superfamilies would be discovered by deep exploration of new SINEs in metazoan genomes. Here we de...

Lead Screening for HIV-1 Integrase (IN Inhibited by Traditional Chinese Medicine

Directory of Open Access Journals (Sweden)

Tzu-Chieh Hung

2014-01-01

Full Text Available Human immunodeficiency virus causes the acquired immunodeficiency syndrome (AIDS and becomes a serious world-wide problem because of this disease's rapid propagation and incurability. Integrase strand transfer inhibitors (INSTIs supports HIV have rapid drug resistance for antitreatment. Screening the traditional Chinese medicine (TCM database by simulating molecular docking and molecular dynamics may select molecular compounds to inhibit INSTIs against HIV drug resistance. (S-cathinone and (1S,2S-norpseudoephedrine are selected based on structure and ligand-based drugs are designed and then get higher bioactivity predicted score from SVM than Raltegravir and other TCM compounds. The molecular dynamics are helpful in the analysis and detection of protein-ligand interactions. According to the docking poses, hydrophobic interactions and hydrogen bond variations define the main regions of important amino acids in integrase. In addition to the detection of TCM compound efficacy, we suggest (1S,2S-norpseudoephedrine is better than the others based on the analysis of interaction and the effect on the structural variation.

Keanekaragaman Jenis Kupu-Kupu Superfamili Papilionoidae di Banyuwindu, Limbangan Kendal

Directory of Open Access Journals (Sweden)

Ratna Oqtafiana

2013-03-01

Full Text Available Kupu-kupu turut memberi andil dalam mempertahankan keseimbangan ekosistem dan memperkaya keanekaragaman hayati. Tujuan dari penelitian ini adalah untuk mengetahui keanekaragaman jenis kupu-kupu superfamili Papilionoidae di Dukuh Banyuwindu Desa Limbangan Kecamatan Limbangan Kabupaten Kendal khususnya di habitat hutan sekunder, permukiman, Daerah Aliran Sungai (DAS dan persawahan.Populasi dalam penelitian ini adalah semua jenis kupu-kupu superfamili Papilionoidae yang ada di Banyuwindu, Limbangan Kendal. Sampel penelitian ini adalah jenis kupu-kupu superfamili Papilionoidae yang teramati di Banyuwindu Limbangan Kendal khususnya di habitat hutan sekunder, permukiman, DAS dan persawahan. Penelitian dilakukan dengan metode Indeks Point Abudance (IPA atau metode titik hitung.Hasil penelitian ditemukan sebanyak 62 jenis kupu-kupu superfamili Papilionoidae yang terdiri dari 737 individu yang tergolong kedalam empat famili yaitu Papilionidae, Pieridae, Lycaenidae dan Nymphalidae. Hasil analisis indeks keanekaragaman jenis berkisar antara 2,74-3,09, indeks kemerataan jenis berkisar antara 0,86-0,87 dan memiliki dominansi berkisar antara 0,07-0,09. Indeks keanekaragaman jenis dan indeks kemerataan jenis tertinggi tercatat pada habitat permukiman yaitu 3,09 dan 0,87 dan memiliki dominansi 0,07 sedangkan terendah tercatat pada habitat persawahan yaitu 2,74 dan 0,86 dan memiliki dominansi 0,07.Butterfly also contribute in maintaining the ecological balance and enrich biodiversity. The aim of this research was to determine the diversity of butterflies’ superfamily Papilionoidae in Banyuwindu Hamlet Limbangan Sub district Kendal Regency, especially in the secondary forest habitat, settlements, river flow area (RFA and rice field. The population in this research were all kinds of butterflies’ Papilionoidae superfamily in Banyuwindu, Limbangan Kendal. The sample was kind of butterfly superfamily Papilionoidae that observed in Banyuwindu Limbangan Kendal

Our retroviral heritage.

Science.gov (United States)

Patience, C; Wilkinson, D A; Weiss, R A

1997-03-01

Darwin could not have foretold that we are descended from viruses as well as from apes. While there is clear evidence that viral diseases, such as polio and rabies, affected ancient civilizations, viruses were not defined until the early years of this century, shortly after the rediscovery of mendelian genetics. That retroviral genomes can oscillate between infectious and genetic modes of transmission seemed preposterous before the discovery of reverse transcription in 1970. Those of us who had earlier provided mendelian evidence for germ-line transmission of retroviruses were subject of friendly ridicule. Today, the shunting of genetic elements between chromosomes and RNA, and the generation of processed pseudogenes, seems commonplace. It is timely, however, to revisit the topic of human endogenous retroviruses-the subject of this article.

High-resolution structure of a retroviral protease folded as a monomer

International Nuclear Information System (INIS)

Gilski, Miroslaw; Kazmierczyk, Maciej; Krzywda, Szymon; Zábranská, Helena; Cooper, Seth; Popović, Zoran; Khatib, Firas; DiMaio, Frank; Thompson, James; Baker, David; Pichová, Iva; Jaskolski, Mariusz

2011-01-01

The crystal structure of Mason–Pfizer monkey virus protease folded as a monomer has been solved by molecular replacement using a model generated by players of the online game Foldit. The structure shows at high resolution the details of a retroviral protease folded as a monomer which can guide rational design of protease dimerization inhibitors as retroviral drugs. Mason–Pfizer monkey virus (M-PMV), a D-type retrovirus assembling in the cytoplasm, causes simian acquired immunodeficiency syndrome (SAIDS) in rhesus monkeys. Its pepsin-like aspartic protease (retropepsin) is an integral part of the expressed retroviral polyproteins. As in all retroviral life cycles, release and dimerization of the protease (PR) is strictly required for polyprotein processing and virion maturation. Biophysical and NMR studies have indicated that in the absence of substrates or inhibitors M-PMV PR should fold into a stable monomer, but the crystal structure of this protein could not be solved by molecular replacement despite countless attempts. Ultimately, a solution was obtained in mr-rosetta using a model constructed by players of the online protein-folding game Foldit. The structure indeed shows a monomeric protein, with the N- and C-termini completely disordered. On the other hand, the flap loop, which normally gates access to the active site of homodimeric retropepsins, is clearly traceable in the electron density. The flap has an unusual curled shape and a different orientation from both the open and closed states known from dimeric retropepsins. The overall fold of the protein follows the retropepsin canon, but the C α deviations are large and the active-site ‘DTG’ loop (here NTG) deviates up to 2.7 Å from the standard conformation. This structure of a monomeric retropepsin determined at high resolution (1.6 Å) provides important extra information for the design of dimerization inhibitors that might be developed as drugs for the treatment of retroviral infections

Designer TGFβ superfamily ligands with diversified functionality.

Directory of Open Access Journals (Sweden)

George P Allendorph

Full Text Available Transforming Growth Factor--beta (TGFβ superfamily ligands, including Activins, Growth and Differentiation Factors (GDFs, and Bone Morphogenetic Proteins (BMPs, are excellent targets for protein-based therapeutics because of their pervasiveness in numerous developmental and cellular processes. We developed a strategy termed RASCH (Random Assembly of Segmental Chimera and Heteromer, to engineer chemically-refoldable TGFβ superfamily ligands with unique signaling properties. One of these engineered ligands, AB208, created from Activin-βA and BMP-2 sequences, exhibits the refolding characteristics of BMP-2 while possessing Activin-like signaling attributes. Further, we find several additional ligands, AB204, AB211, and AB215, which initiate the intracellular Smad1-mediated signaling pathways more strongly than BMP-2 but show no sensitivity to the natural BMP antagonist Noggin unlike natural BMP-2. In another design, incorporation of a short N-terminal segment from BMP-2 was sufficient to enable chemical refolding of BMP-9, without which was never produced nor refolded. Our studies show that the RASCH strategy enables us to expand the functional repertoire of TGFβ superfamily ligands through development of novel chimeric TGFβ ligands with diverse biological and clinical values.

Inference of functional properties from large-scale analysis of enzyme superfamilies.

Science.gov (United States)

Brown, Shoshana D; Babbitt, Patricia C

2012-01-02

As increasingly large amounts of data from genome and other sequencing projects become available, new approaches are needed to determine the functions of the proteins these genes encode. We show how large-scale computational analysis can help to address this challenge by linking functional information to sequence and structural similarities using protein similarity networks. Network analyses using three functionally diverse enzyme superfamilies illustrate the use of these approaches for facile updating and comparison of available structures for a large superfamily, for creation of functional hypotheses for metagenomic sequences, and to summarize the limits of our functional knowledge about even well studied superfamilies.

Cross- and Co-Packaging of Retroviral RNAs and Their Consequences

Directory of Open Access Journals (Sweden)

Lizna M. Ali

2016-10-01

Full Text Available Retroviruses belong to the family Retroviridae and are ribonucleoprotein (RNP particles that contain a dimeric RNA genome. Retroviral particle assembly is a complex process, and how the virus is able to recognize and specifically capture the genomic RNA (gRNA among millions of other cellular and spliced retroviral RNAs has been the subject of extensive investigation over the last two decades. The specificity towards RNA packaging requires higher order interactions of the retroviral gRNA with the structural Gag proteins. Moreover, several retroviruses have been shown to have the ability to cross-/co-package gRNA from other retroviruses, despite little sequence homology. This review will compare the determinants of gRNA encapsidation among different retroviruses, followed by an examination of our current understanding of the interaction between diverse viral genomes and heterologous proteins, leading to their cross-/co-packaging. Retroviruses are well-known serious animal and human pathogens, and such a cross-/co-packaging phenomenon could result in the generation of novel viral variants with unknown pathogenic potential. At the same time, however, an enhanced understanding of the molecular mechanisms involved in these specific interactions makes retroviruses an attractive target for anti-viral drugs, vaccines, and vectors for human gene therapy.

Luminometric method for screening retroviral protease inhibitors

Czech Academy of Sciences Publication Activity Database

Horáková, D.; Rumlová, Michaela; Pichová, Iva; Ruml, Tomáš

2005-01-01

Roč. 345, č. 1 (2005), s. 96-101 ISSN 0003-2697 R&D Projects: GA AV ČR(CZ) IAA4055304; GA MŠk(CZ) 1M0508; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506 Keywords : retroviral protease * inhibitors * luminescent assay Subject RIV: CE - Biochemistry Impact factor: 2.670, year: 2005

Retroviral restriction and dependency factors in primates and carnivores

Science.gov (United States)

Fadel, Hind J.; Poeschla, Eric M.

2014-01-01

Recent studies have extended the rapidly developing retroviral restriction factor field to cells of carnivore species. Carnivoran genomes, and the domestic cat genome in particular, are revealing intriguing properties vis-à;-vis the primate and feline lentiviruses, not only with respect to their repertoires of virus-blocking restriction factors but also replication-enabling dependency factors. Therapeutic application of restriction factors is envisioned for human immunodeficiency virus (HIV) disease and the feline immunodeficiency virus (FIV) model has promise for testing important hypotheses at the basic and translational level. Feline cell-tropic HIV-1 clones have also been generated by a strategy of restriction factor evasion. We review progress in this area in the context of what is known about retroviral restriction factors such as TRIM5alpha, TRIMCyp, APOBEC3 proteins and BST-2/Tetherin. PMID:21715018

Inference of Functional Properties from Large-scale Analysis of Enzyme Superfamilies*

Science.gov (United States)

Brown, Shoshana D.; Babbitt, Patricia C.

2012-01-01

As increasingly large amounts of data from genome and other sequencing projects become available, new approaches are needed to determine the functions of the proteins these genes encode. We show how large-scale computational analysis can help to address this challenge by linking functional information to sequence and structural similarities using protein similarity networks. Network analyses using three functionally diverse enzyme superfamilies illustrate the use of these approaches for facile updating and comparison of available structures for a large superfamily, for creation of functional hypotheses for metagenomic sequences, and to summarize the limits of our functional knowledge about even well studied superfamilies. PMID:22069325

Application of Live-Cell RNA Imaging Techniques to the Study of Retroviral RNA Trafficking

Directory of Open Access Journals (Sweden)

Darrin V. Bann

2012-06-01

Full Text Available Retroviruses produce full-length RNA that serves both as a genomic RNA (gRNA, which is encapsidated into virus particles, and as an mRNA, which directs the synthesis of viral structural proteins. However, we are only beginning to understand the cellular and viral factors that influence trafficking of retroviral RNA and the selection of the RNA for encapsidation or translation. Live cell imaging studies of retroviral RNA trafficking have provided important insight into many aspects of the retrovirus life cycle including transcription dynamics, nuclear export of viral RNA, translational regulation, membrane targeting, and condensation of the gRNA during virion assembly. Here, we review cutting-edge techniques to visualize single RNA molecules in live cells and discuss the application of these systems to studying retroviral RNA trafficking.

Cloning, purification and structure determination of the HIV integrase-binding domain of lens epithelium-derived growth factor.

Science.gov (United States)

Hannon, Clare; Cruz-Migoni, Abimael; Platonova, Olga; Owen, Robin L; Nettleship, Joanne E; Miller, Ami; Carr, Stephen B; Harris, Gemma; Rabbitts, Terence H; Phillips, Simon E V

2018-03-01

Lens epithelium-derived growth factor (LEDGF)/p75 is the dominant binding partner of HIV-1 integrase in human cells. The crystal structure of the HIV integrase-binding domain (IBD) of LEDGF has been determined in the absence of ligand. IBD was overexpressed in Escherichia coli, purified and crystallized by sitting-drop vapour diffusion. X-ray diffraction data were collected at Diamond Light Source to a resolution of 2.05 Å. The crystals belonged to space group P2 1 , with eight polypeptide chains in the asymmetric unit arranged as an unusual octamer composed of four domain-swapped IBD dimers. IBD exists as a mixture of monomers and dimers in concentrated solutions, but the dimers are unlikely to be biologically relevant.

Anti-retroviral therapy-induced status epilepticus in "pseudo-HIV serodeconversion".

Science.gov (United States)

Etgen, Thorleif; Eberl, Bernhard; Freudenberger, Thomas

2010-01-01

Diligence in the interpretation of results is essential as information gained from the psychiatric patient's history might often be restricted. Nonobservance of established guidelines may lead to a wrong diagnosis, induce a false therapy and result in life-threatening situations. Communication errors between hospitals and doctors and uncritical acceptance of prior diagnoses add substantially to this problem. We present a patient with alcohol-related dementia who received anti-retroviral therapy that promoted a non-convulsive status epilepticus. HIV serodeconversion was considered after our laboratory result yielded a HIV-negative status. Critical review of previous diagnostic investigations revealed several errors in the diagnosis of HIV infection leading to a "pseudo-serodeconversion." Finally, anti-retroviral therapy could be discontinued. Copyright © 2010 Elsevier Inc. All rights reserved.

Reporter gene expression in fish following cutaneous infection with pantropic retroviral vectors.

Science.gov (United States)

Paul, T A; Burns, J C; Shike, H; Getchell, R; Bowser, P R; Whitlock, K E; Casey, J W

2001-06-01

A central issue in gene delivery systems is choosing promoters that will direct defined and sustainable levels of gene expression. Pantropic retroviral vectors provide a means to insert genes into either somatic or germline cells. In this study, we focused on somatic cell infection by evaluating the activity of 3 promoters inserted by vectors into fish cell lines and fish skin using pantropic retroviruses. In bluegill and zebrafish cell lines, the highest levels of luciferase expression were observed from the 5' murine leukemia virus long terminal repeat of the retroviral vector. The Rous sarcoma virus long terminal repeat and cytomegalovirus early promoter, as internal promoters, generated lower levels of luciferase. Luciferase reporter vectors infected zebrafish skin, as measured by the presence of viral DNA, and expressed luciferase. We infected developing walleye dermal sarcomas with retroviral vectors to provide an environment with enhanced cell proliferation, a condition necessary for integration of the provirus into the host genome. We demonstrated a 4-fold to 7-fold increase in luciferase gene expression in tumor tissue over infections in normal walleye skin.

Large-Scale Analysis Exploring Evolution of Catalytic Machineries and Mechanisms in Enzyme Superfamilies.

Science.gov (United States)

Furnham, Nicholas; Dawson, Natalie L; Rahman, Syed A; Thornton, Janet M; Orengo, Christine A

2016-01-29

Enzymes, as biological catalysts, form the basis of all forms of life. How these proteins have evolved their functions remains a fundamental question in biology. Over 100 years of detailed biochemistry studies, combined with the large volumes of sequence and protein structural data now available, means that we are able to perform large-scale analyses to address this question. Using a range of computational tools and resources, we have compiled information on all experimentally annotated changes in enzyme function within 379 structurally defined protein domain superfamilies, linking the changes observed in functions during evolution to changes in reaction chemistry. Many superfamilies show changes in function at some level, although one function often dominates one superfamily. We use quantitative measures of changes in reaction chemistry to reveal the various types of chemical changes occurring during evolution and to exemplify these by detailed examples. Additionally, we use structural information of the enzymes active site to examine how different superfamilies have changed their catalytic machinery during evolution. Some superfamilies have changed the reactions they perform without changing catalytic machinery. In others, large changes of enzyme function, in terms of both overall chemistry and substrate specificity, have been brought about by significant changes in catalytic machinery. Interestingly, in some superfamilies, relatives perform similar functions but with different catalytic machineries. This analysis highlights characteristics of functional evolution across a wide range of superfamilies, providing insights that will be useful in predicting the function of uncharacterised sequences and the design of new synthetic enzymes. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nurses' perceptions about Botswana patients' anti-retroviral therapy ...

African Journals Online (AJOL)

Anti-retroviral drugs(ARVs) are supplied free of charge in Botswana. Lifelong adherence to antiretroviral therapy (ART) is vital to improve the patient's state of well-being and to prevent the development of strains of the human immunodefi ciency virus (HIV) that are resistant to ART. Persons with ART-resistant strains of HIV ...

HIV-2 integrase polymorphisms and longitudinal genotypic analysis of HIV-2 infected patients failing a raltegravir-containing regimen.

Science.gov (United States)

Cavaco-Silva, Joana; Abecasis, Ana; Miranda, Ana Cláudia; Poças, José; Narciso, Jorge; Águas, Maria João; Maltez, Fernando; Almeida, Isabel; Germano, Isabel; Diniz, António; Gonçalves, Maria de Fátima; Gomes, Perpétua; Cunha, Celso; Camacho, Ricardo Jorge

2014-01-01

To characterize the HIV-2 integrase gene polymorphisms and the pathways to resistance of HIV-2 patients failing a raltegravir-containing regimen, we studied 63 integrase strand transfer inhibitors (INSTI)-naïve patients, and 10 heavily pretreated patients exhibiting virological failure while receiving a salvage raltegravir-containing regimen. All patients were infected by HIV-2 group A. 61.4% of the integrase residues were conserved, including the catalytic motif residues. No INSTI-major resistance mutations were detected in the virus population from naïve patients, but two amino acids that are secondary resistance mutations to INSTIs in HIV-1 were observed. The 10 raltegravir-experienced patients exhibited resistance mutations via three main genetic pathways: N155H, Q148R, and eventually E92Q - T97A. The 155 pathway was preferentially used (7/10 patients). Other mutations associated to raltegravir resistance in HIV-1 were also observed in our HIV-2 population (V151I and D232N), along with several novel mutations previously unreported. Data retrieved from this study should help build a more robust HIV-2-specific algorithm for the genotypic interpretation of raltegravir resistance, and contribute to improve the clinical monitoring of HIV-2-infected patients.

Diversity, classification and function of the plant protein kinase superfamily

OpenAIRE

Lehti-Shiu, Melissa D.; Shiu, Shin-Han

2012-01-01

Eukaryotic protein kinases belong to a large superfamily with hundreds to thousands of copies and are components of essentially all cellular functions. The goals of this study are to classify protein kinases from 25 plant species and to assess their evolutionary history in conjunction with consideration of their molecular functions. The protein kinase superfamily has expanded in the flowering plant lineage, in part through recent duplications. As a result, the flowering plant protein kinase r...

Retroviral vectors encoding ADA regulatory locus control region provide enhanced T-cell-specific transgene expression.

Science.gov (United States)

Trinh, Alice T; Ball, Bret G; Weber, Erin; Gallaher, Timothy K; Gluzman-Poltorak, Zoya; Anderson, French; Basile, Lena A

2009-12-30

Murine retroviral vectors have been used in several hundred gene therapy clinical trials, but have fallen out of favor for a number of reasons. One issue is that gene expression from viral or internal promoters is highly variable and essentially unregulated. Moreover, with retroviral vectors, gene expression is usually silenced over time. Mammalian genes, in contrast, are characterized by highly regulated, precise levels of expression in both a temporal and a cell-specific manner. To ascertain if recapitulation of endogenous adenosine deaminase (ADA) expression can be achieved in a vector construct we created a new series of Moloney murine leukemia virus (MuLV) based retroviral vector that carry human regulatory elements including combinations of the ADA promoter, the ADA locus control region (LCR), ADA introns and human polyadenylation sequences in a self-inactivating vector backbone. A MuLV-based retroviral vector with a self-inactivating (SIN) backbone, the phosphoglycerate kinase promoter (PGK) and the enhanced green fluorescent protein (eGFP), as a reporter gene, was generated. Subsequent vectors were constructed from this basic vector by deletion or addition of certain elements. The added elements that were assessed are the human ADA promoter, human ADA locus control region (LCR), introns 7, 8, and 11 from the human ADA gene, and human growth hormone polyadenylation signal. Retroviral vector particles were produced by transient three-plasmid transfection of 293T cells. Retroviral vectors encoding eGFP were titered by transducing 293A cells, and then the proportion of GFP-positive cells was determined using fluorescence-activated cell sorting (FACS). Non T-cell and T-cell lines were transduced at a multiplicity of infection (MOI) of 0.1 and the yield of eGFP transgene expression was evaluated by FACS analysis using mean fluorescent intensity (MFI) detection. Vectors that contained the ADA LCR were preferentially expressed in T-cell lines. Further improvements

Retroviral vectors encoding ADA regulatory locus control region provide enhanced T-cell-specific transgene expression

Science.gov (United States)

2009-01-01

Background Murine retroviral vectors have been used in several hundred gene therapy clinical trials, but have fallen out of favor for a number of reasons. One issue is that gene expression from viral or internal promoters is highly variable and essentially unregulated. Moreover, with retroviral vectors, gene expression is usually silenced over time. Mammalian genes, in contrast, are characterized by highly regulated, precise levels of expression in both a temporal and a cell-specific manner. To ascertain if recapitulation of endogenous adenosine deaminase (ADA) expression can be achieved in a vector construct we created a new series of Moloney murine leukemia virus (MuLV) based retroviral vector that carry human regulatory elements including combinations of the ADA promoter, the ADA locus control region (LCR), ADA introns and human polyadenylation sequences in a self-inactivating vector backbone. Methods A MuLV-based retroviral vector with a self-inactivating (SIN) backbone, the phosphoglycerate kinase promoter (PGK) and the enhanced green fluorescent protein (eGFP), as a reporter gene, was generated. Subsequent vectors were constructed from this basic vector by deletion or addition of certain elements. The added elements that were assessed are the human ADA promoter, human ADA locus control region (LCR), introns 7, 8, and 11 from the human ADA gene, and human growth hormone polyadenylation signal. Retroviral vector particles were produced by transient three-plasmid transfection of 293T cells. Retroviral vectors encoding eGFP were titered by transducing 293A cells, and then the proportion of GFP-positive cells was determined using fluorescence-activated cell sorting (FACS). Non T-cell and T-cell lines were transduced at a multiplicity of infection (MOI) of 0.1 and the yield of eGFP transgene expression was evaluated by FACS analysis using mean fluorescent intensity (MFI) detection. Results Vectors that contained the ADA LCR were preferentially expressed in T

Patients' perceptions of a rural decentralised anti-retroviral therapy ...

African Journals Online (AJOL)

Background: Geographical and financial barriers hamper accessibility to HIV services for rural communities. The government has introduced the nurse initiated management of anti-retroviral therapy at primary health care level, in an effort to improve patient access and reduce patient loads on facilities further up the system.

Concise classification of the genomic porcine endogenous retroviral gamma1 load to defined lineages.

Science.gov (United States)

Klymiuk, Nikolai; Wolf, Eckhard; Aigner, Bernhard

2008-02-05

We investigated the infection history of porcine endogenous retroviruses (PERV) gamma1 by analyzing published env and LTR sequences. PERV sequences from various breeds, porcine cell lines and infected human primary cells were included in the study. We identified a considerable number of retroviral lineages indicating multiple independent colonization events of the porcine genome. A recent boost of the proviral load in an isolated pig herd and exclusive occurrence of distinct lineages in single studies indicated the ongoing colonization of the porcine genome with endogenous retroviruses. Retroviral recombination between co-packaged genomes was a general factor for PERV gamma1 diversity which indicated the simultaneous expression of different proviral loci over a period of time. In total, our detailed description of endogenous retroviral lineages is the prerequisite for breeding approaches to minimize the infectious potential of porcine tissues for the subsequent use in xenotransplantation.

Removal of envelope protein-free retroviral vectors by anion-exchange chromatography to improve product quality.

Science.gov (United States)

Rodrigues, Teresa; Alves, Ana; Lopes, António; Carrondo, Manuel J T; Alves, Paula M; Cruz, Pedro E

2008-10-01

We have investigated the role of the retroviral lipid bilayer and envelope proteins in the adsorption of retroviral vectors (RVs) to a Fractogel DEAE matrix. Intact RVs and their degradation components (envelope protein-free vectors and solubilized vector components) were adsorbed to this matrix and eluted using a linear gradient. Envelope protein-free RVs (Env(-)) and soluble envelope proteins (gp70) eluted in a significantly lower range of conductivities than intact RVs (Env(+)) (13.7-30 mS/cm for Env(-) and gp70 proteins vs. 47-80 mS/cm for Env(+)). The zeta (zeta)-potential of Env(+) and Env(-) vectors was evaluated showing that envelope proteins define the pI of the viral particles (pI (Env(+)) improvement to the quality of retroviral preparations for gene therapy applications.

Raltegravir, elvitegravir, and metoogravir: the birth of "me-too" HIV-1 integrase inhibitors

Directory of Open Access Journals (Sweden)

Neamati Nouri

2009-04-01

Full Text Available Abstract Correction to Erik Serrao, Srinivas Odde, Kavya Ramkumar and Nouri Neamati: Raltegravir, elvitegravir, and metoogravir: the birth of "me-too" HIV-1 integrase inhibitors. Retrovirology 2009, 6:25. Since the recent publication of our article (Neamati, Retrovirology 2009, 6:25, we have noticed an error which we would like to correct and we would like to apologise to the readers for this mistake.

Next-generation site-directed transgenesis in the malaria vector mosquito Anopheles gambiae: self-docking strains expressing germline-specific phiC31 integrase.

Directory of Open Access Journals (Sweden)

Janet M Meredith

Full Text Available Diseases transmitted by mosquitoes have a devastating impact on global health and the situation is complicated due to difficulties with both existing control measures and the impact of climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. The Streptomyces phage phiC31 integrase system has been successfully adapted for site-directed transgene integration in a range of insects, thus overcoming many limitations due to size constraints and random integration associated with transposon-mediated transformation. Using this technology, we previously published the first site-directed transformation of Anopheles gambiae, the principal vector of human malaria. Mosquitoes were initially engineered to incorporate the phiC31 docking site at a defined genomic location. A second phase of genetic modification then achieved site-directed integration of an anti-malarial effector gene. In the current publication we report improved efficiency and utility of the phiC31 integrase system following the generation of Anopheles gambiae self-docking strains. Four independent strains, with docking sites at known locations on three different chromosome arms, were engineered to express integrase under control of the regulatory regions of the nanos gene from Anopheles gambiae. The resulting protein accumulates in the posterior oocyte to provide integrase activity at the site of germline development. Two self-docking strains, exhibiting significantly different levels of integrase expression, were assessed for site-directed transgene integration and found to demonstrate greatly improved survival and efficiency of transformation. In the fight against malaria, it is imperative to establish a broad repertoire of both anti-malarial effector genes and tissue-specific promoters to regulate their expression, enabling those offering maximum effect with minimum fitness

Pregnancy outcome of HIV-infected women on anti-retroviral therapy ...

African Journals Online (AJOL)

... received anti-retroviral treatment at the University of Port Harcourt Teaching Hospital ... 3.8% started in 2nd trimester of pregnancy and 14.1% during labour. ... was minimal and stresses the value of antiretroviral treatment in the prevention of ...

Virus evolution reveals an exclusive role for LEDGF/p75 in chromosomal tethering of HIV.

Directory of Open Access Journals (Sweden)

Anneleen Hombrouck

2007-03-01

Full Text Available Retroviruses by definition insert their viral genome into the host cell chromosome. Although the key player of retroviral integration is viral integrase, a role for cellular cofactors has been proposed. Lentiviral integrases use the cellular protein LEDGF/p75 to tether the preintegration complex to the chromosome, although the existence of alternative host proteins substituting for the function of LEDGF/p75 in integration has been proposed. Truncation mutants of LEDGF/p75 lacking the chromosome attachment site strongly inhibit HIV replication by competition for the interaction with integrase. In an attempt to select HIV strains that can overcome the inhibition, we now have used T-cell lines that stably express a C-terminal fragment of LEDGF/p75. Despite resistance development, the affinity of integrase for LEDGF/p75 is reduced and replication kinetics in human primary T cells is impaired. Detection of the integrase mutations A128T and E170G at key positions in the LEDGF/p75-integrase interface provides in vivo evidence for previously reported crystallographic data. Moreover, the complementary inhibition by LEDGF/p75 knockdown and mutagenesis at the integrase-LEDGF/p75 interface points to the incapability of HIV to circumvent LEDGF/p75 function during proviral integration. Altogether, the data provide a striking example of the power of viral molecular evolution. The results underline the importance of the LEDGF/p75 HIV-1 interplay as target for innovative antiviral therapy. Moreover, the role of LEDGF/p75 in targeting integration will stimulate research on strategies to direct gene therapy vectors into safe landing sites.

Evolutionary and molecular foundations of multiple contemporary functions of the nitroreductase superfamily.

Science.gov (United States)

Akiva, Eyal; Copp, Janine N; Tokuriki, Nobuhiko; Babbitt, Patricia C

2017-11-07

Insight regarding how diverse enzymatic functions and reactions have evolved from ancestral scaffolds is fundamental to understanding chemical and evolutionary biology, and for the exploitation of enzymes for biotechnology. We undertook an extensive computational analysis using a unique and comprehensive combination of tools that include large-scale phylogenetic reconstruction to determine the sequence, structural, and functional relationships of the functionally diverse flavin mononucleotide-dependent nitroreductase (NTR) superfamily (>24,000 sequences from all domains of life, 54 structures, and >10 enzymatic functions). Our results suggest an evolutionary model in which contemporary subgroups of the superfamily have diverged in a radial manner from a minimal flavin-binding scaffold. We identified the structural design principle for this divergence: Insertions at key positions in the minimal scaffold that, combined with the fixation of key residues, have led to functional specialization. These results will aid future efforts to delineate the emergence of functional diversity in enzyme superfamilies, provide clues for functional inference for superfamily members of unknown function, and facilitate rational redesign of the NTR scaffold. Copyright © 2017 the Author(s). Published by PNAS.

Contribution of HIV minority variants to drug resistance in an integrase strand transfer inhibitor-based therapy

Czech Academy of Sciences Publication Activity Database

Weber, Jan; Gibson, R. M.; Meyer, A. M.; Winner, D.; Robertson, D. L.; Miller, M. D.; Quinones-Mateu, M. E.

2013-01-01

Roč. 18, Suppl. 1 (2013), A66-A66 ISSN 1359-6535. [International Workshop on HIV & Hepatitis Virus Drug Resistance Curative Strategies. 04.06.2013-08.06.2013, Toronto] Institutional support: RVO:61388963 Keywords : HIV minority variants * integrase inhibitor * replicative fitness Subject RIV: CE - Biochemistry

Discovery of small-molecule HIV-1 fusion and integrase inhibitors oleuropein and hydroxytyrosol: Part I. Integrase inhibition

International Nuclear Information System (INIS)

Lee-Huang, Sylvia; Huang, Philip Lin; Zhang Dawei; Lee, Jae Wook; Bao Ju; Sun Yongtao; Chang, Young-Tae; Zhang, John; Huang, Paul Lee

2007-01-01

We have identified oleuropein (Ole) and hydroxytyrosol (HT) as a unique class of HIV-1 inhibitors from olive leaf extracts effective against viral fusion and integration. We used molecular docking simulation to study the interactions of Ole and HT with viral targets. We find that Ole and HT bind to the conserved hydrophobic pocket on the surface of the HIV-gp41 fusion domain by hydrogen bonds with Q577 and hydrophobic interactions with I573, G572, and L568 on the gp41 N-terminal heptad repeat peptide N36, interfering with formation of the gp41 fusion-active core. To test and confirm modeling predications, we examined the effect of Ole and HT on HIV-1 fusion complex formation using native polyacrylamide gel electrophoresis and circular dichroism spectroscopy. Ole and HT exhibit dose-dependent inhibition on HIV-1 fusion core formation with EC 50 s of 66-58 nM, with no detectable toxicity. Our findings on effects of HIV-1 integrase are reported in the subsequent article

Systematic classification of the His-Me finger superfamily.

Science.gov (United States)

Jablonska, Jagoda; Matelska, Dorota; Steczkiewicz, Kamil; Ginalski, Krzysztof

2017-11-16

The His-Me finger endonucleases, also known as HNH or ββα-metal endonucleases, form a large and diverse protein superfamily. The His-Me finger domain can be found in proteins that play an essential role in cells, including genome maintenance, intron homing, host defense and target offense. Its overall structural compactness and non-specificity make it a perfectly-tailored pathogenic module that participates on both sides of inter- and intra-organismal competition. An extremely low sequence similarity across the superfamily makes it difficult to identify and classify new His-Me fingers. Using state-of-the-art distant homology detection methods, we provide an updated and systematic classification of His-Me finger proteins. In this work, we identified over 100 000 proteins and clustered them into 38 groups, of which three groups are new and cannot be found in any existing public domain database of protein families. Based on an analysis of sequences, structures, domain architectures, and genomic contexts, we provide a careful functional annotation of the poorly characterized members of this superfamily. Our results may inspire further experimental investigations that should address the predicted activity and clarify the potential substrates, to provide more detailed insights into the fundamental biological roles of these proteins. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Transient receptor potential channel superfamily: Role in lower urinary tract function.

Science.gov (United States)

Ogawa, Teruyuki; Imamura, Tetsuya; Nakazawa, Masaki; Hiragata, Shiro; Nagai, Takashi; Minagawa, Tomonori; Yokoyama, Hitoshi; Ishikawa, Masakuni; Domen, Takahisa; Ishizuka, Osamu

2015-11-01

Lower urinary tract symptoms associated with neurogenic bladder and overactive bladder syndrome are mediated in part by members of the transient receptor potential channel superfamily. The best studied member of this superfamily is the vanilloid receptor. Other transient receptor potential channels, such as the melastatin receptor and the ankyrin receptor, are also active in the pathogenesis of lower urinary tract dysfunction. However, the detailed mechanisms by which the transient receptor potential channels contribute to lower urinary tract symptoms are still not clear, and the therapeutic benefits of modulating transient receptor potential channel activity have not been proved in the clinical setting. In the present review, to better understand the pathophysiology and therapeutic potential for lower urinary tract symptoms, we summarize the presence and role of different members of the transient receptor potential channel superfamily in the lower urinary tract. © 2015 The Japanese Urological Association.

Retroviral Gag protein-RNA interactions: Implications for specific genomic RNA packaging and virion assembly.

Science.gov (United States)

Olson, Erik D; Musier-Forsyth, Karin

2018-03-31

Retroviral Gag proteins are responsible for coordinating many aspects of virion assembly. Gag possesses two distinct nucleic acid binding domains, matrix (MA) and nucleocapsid (NC). One of the critical functions of Gag is to specifically recognize, bind, and package the retroviral genomic RNA (gRNA) into assembling virions. Gag interactions with cellular RNAs have also been shown to regulate aspects of assembly. Recent results have shed light on the role of MA and NC domain interactions with nucleic acids, and how they jointly function to ensure packaging of the retroviral gRNA. Here, we will review the literature regarding RNA interactions with NC, MA, as well as overall mechanisms employed by Gag to interact with RNA. The discussion focuses on human immunodeficiency virus type-1, but other retroviruses will also be discussed. A model is presented combining all of the available data summarizing the various factors and layers of selection Gag employs to ensure specific gRNA packaging and correct virion assembly. Copyright © 2018 Elsevier Ltd. All rights reserved.

Retroviral packaging cells encapsulated in TheraCyte immunoisolation devices enable long-term in vivo gene delivery.

Science.gov (United States)

Krupetsky, Anna; Parveen, Zahida; Marusich, Elena; Goodrich, Adrienne; Dornburg, Ralph

2003-05-01

The method of delivering a therapeutic gene into a patient is still one of the major obstacles towards successful human gene therapy. Here we describe a novel gene delivery approach using TheraCyte immunoisolation devices. Retroviral vector producing cells, derived from the avian retrovirus spleen necrosis virus, SNV, were encapsulated in TheraCyte devices and tested for the release of retroviral vectors. In vitro experiments show that such devices release infectious retroviral vectors into the tissue culture medium for up to 4 months. When such devices were implanted subcutaneously in SCID mice, infectious virus was released into the blood stream. There, the vectors were transported to and infected tumors, which had been induced by subcutaneous injection of tissue culture cells. Thus, this novel concept of a continuous, long-term gene delivery may constitute an attractive approach for future in vivo human gene therapy.

Gaps in the Implementation of Anti-Retroviral Treatment: A Case for ...

African Journals Online (AJOL)

... of Anti-Retroviral Treatment: A Case for Addressing Gender and Mental Health ... to score successes in ensuring adherence to ART as well as reducing new HIV ... lack of established clinical infrastructure, negative social stigma and the cost ...

Changing T cell specificity by retroviral T cell receptor display

NARCIS (Netherlands)

Kessels, H. W.; van den Boom, M. D.; Spits, H.; Hooijberg, E.; Schumacher, T. N.

2000-01-01

The diversity of the T cell receptor (TCR) repertoire is limited, because of the processes of positive and negative T cell selection. To obtain T cells with specificities beyond the immune system's capacity, we have developed a strategy for retroviral TCR display. In this approach, a library of T

Molecular dynamics simulation studies of the wild type and E92Q/N155H mutant of Elvitegravir-resistance HIV-1 integrase.

Science.gov (United States)

Chen, Qi; Cheng, Xiaolin; Wei, Dongqing; Xu, Qin

2015-03-01

Although Elvitegravir (EVG) is a newly developed antiretrovirals drug to treat the acquired immunodeficiency syndrome (AIDS), drug resistance has already been found in clinic, such as E92Q/N155H and Q148H/G140S. Several structural investigations have already been reported to reveal the molecular mechanism of the drug resistance. As full length crystal structure for HIV-1 integrase is still unsolved, we herein use the crystal structure of the full length prototype foamy virus (PFV) in complex with virus DNA and inhibitor Elvitegravir as a template to construct the wild type and E92Q/N155H mutant system of HIV-1 integrase. Molecular dynamic simulations was used to revel the binding mode and the drug resistance of the EVG ligand in E92Q/N155H. Several important interactions were discovered between the mutated residues and the residues in the active site of the E92Q/N155H double mutant pattern, and cross correlation and clustering methods were used for detailed analysis. The results from the MD simulation studies will be used to guide the experimental efforts of developing novel inhibitors against drug-resistant HIV integrase mutants.

Functional diversity of the superfamily of K⁺ transporters to meet various requirements.

Science.gov (United States)

Diskowski, Marina; Mikusevic, Vedrana; Stock, Charlott; Hänelt, Inga

2015-09-01

The superfamily of K+ transporters unites proteins from plants, fungi, bacteria, and archaea that translocate K+ and/or Na+ across membranes. These proteins are key components in osmotic regulation, pH homeostasis, and resistance to high salinity and dryness. The members of the superfamily are closely related to K+ channels such as KcsA but also show several striking differences that are attributed to their altered functions. This review highlights these functional differences, focusing on the bacterial superfamily members KtrB, TrkH, and KdpA. The functional variations within the family and comparison to MPM-type K+ channels are discussed in light of the recently solved structures of the Ktr and Trk systems.

Docking studies on a new human immunodeficiency virus integrase-Mg-DNA complex: phenyl ring exploration and synthesis of 1H-benzylindole derivatives through fluorine substitutions.

Science.gov (United States)

Ferro, Stefania; De Luca, Laura; Barreca, Maria Letizia; Iraci, Nunzio; De Grazia, Sara; Christ, Frauke; Witvrouw, Myriam; Debyser, Zeger; Chimirri, Alba

2009-01-22

A new model of HIV-1 integrase-Mg-DNA complex that is useful for docking experiments has been built. It was used to study the binding mode of integrase strand transfer inhibitor 1 (CHI-1043) and other fluorine analogues. Molecular modeling results prompted us to synthesize the designed derivatives which showed potent enzymatic inhibition at nanomolar concentration, high antiviral activity, and low toxicity. Microwave assisted organic synthesis (MAOS) was employed in several steps of the synthetic pathway, thus reducing reaction times and improving yields.

Lineage-specific expansions of retroviral insertions within the genomes of African great apes but not humans and orangutans.

Directory of Open Access Journals (Sweden)

Chris T Yohn

2005-04-01

Full Text Available Retroviral infections of the germline have the potential to episodically alter gene function and genome structure during the course of evolution. Horizontal transmissions between species have been proposed, but little evidence exists for such events in the human/great ape lineage of evolution. Based on analysis of finished BAC chimpanzee genome sequence, we characterize a retroviral element (Pan troglodytes endogenous retrovirus 1 [PTERV1] that has become integrated in the germline of African great ape and Old World monkey species but is absent from humans and Asian ape genomes. We unambiguously map 287 retroviral integration sites and determine that approximately 95.8% of the insertions occur at non-orthologous regions between closely related species. Phylogenetic analysis of the endogenous retrovirus reveals that the gorilla and chimpanzee elements share a monophyletic origin with a subset of the Old World monkey retroviral elements, but that the average sequence divergence exceeds neutral expectation for a strictly nuclear inherited DNA molecule. Within the chimpanzee, there is a significant integration bias against genes, with only 14 of these insertions mapping within intronic regions. Six out of ten of these genes, for which there are expression data, show significant differences in transcript expression between human and chimpanzee. Our data are consistent with a retroviral infection that bombarded the genomes of chimpanzees and gorillas independently and concurrently, 3-4 million years ago. We speculate on the potential impact of such recent events on the evolution of humans and great apes.

Cross-packaging of genetically distinct mouse and primate retroviral RNAs

Directory of Open Access Journals (Sweden)

Jaballah Soumeya

2009-07-01

Full Text Available Abstract Background The mouse mammary tumor virus (MMTV is unique from other retroviruses in having multiple viral promoters, which can be regulated by hormones in a tissue specific manner. This unique property has lead to increased interest in studying MMTV replication with the hope of developing MMTV based vectors for human gene therapy. However, it has recently been reported that related as well as unrelated retroviruses can cross-package each other's genome raising safety concerns towards the use of candidate retroviral vectors for human gene therapy. Therefore, using a trans complementation assay, we looked at the ability of MMTV RNA to be cross-packaged and propagated by an unrelated primate Mason-Pfizer monkey virus (MPMV that has intracellular assembly process similar to that of MMTV. Results Our results revealed that MMTV and MPMV RNAs could be cross-packaged by the heterologous virus particles reciprocally suggesting that pseudotyping between two genetically distinct retroviruses can take place at the RNA level. However, the cross-packaged RNAs could not be propagated further indicating a block at post-packaging events in the retroviral life cycle. To further confirm that the specificity of cross-packaging was conferred by the packaging sequences (ψ, we cloned the packaging sequences of these viruses on expression plasmids that generated non-viral RNAs. Test of these non-viral RNAs confirmed that the reciprocal cross-packaging was primarily due to the recognition of ψ by the heterologous virus proteins. Conclusion The results presented in this study strongly argue that MPMV and MMTV are promiscuous in their ability to cross-package each other's genome suggesting potential RNA-protein interactions among divergent retroviral RNAs proposing that these interactions are more complicated than originally thought. Furthermore, these observations raise the possibility that MMTV and MPMV genomes could also co-package providing substrates for

Molecular dynamics simulation studies of the wild type and E92Q/N155H mutant of Elvitegravir-resistance HIV-1 integrase

Energy Technology Data Exchange (ETDEWEB)

Chen, Qi [Shanghai Jiao Tong Univ., Shanghai (China). State Key Lab. of Microbial Metabolism and College of Life Science and Biotechnology; Cheng, Xiaolin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Molecular Biophysics; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Biochemistry and Cellular and Molecular Biology; Wei, Dongqing [Shanghai Jiao Tong Univ., Shanghai (China). State Key Lab. of Microbial Metabolism and College of Life Science and Biotechnology; Xu, Qin [Shanghai Jiao Tong Univ., Shanghai (China). State Key Lab. of Microbial Metabolism and College of Life Science and Biotechnology

2014-11-06

Although Elvitegravir (EVG) is a newly developed antiretrovirals drug to treat the acquired immunodeficiency syndrome (AIDS), drug resistance has already been found in clinic, such as E92Q/N155H and Q148H/G140S. Several structural investigations have already been reported to reveal the molecular mechanism of the drug resistance. As full length crystal structure for HIV-1 integrase is still unsolved, we use in this paper the crystal structure of the full length prototype foamy virus (PFV) in complex with virus DNA and inhibitor Elvitegravir as a template to construct the wild type and E92Q/N155H mutant system of HIV-1 integrase. Molecular dynamic simulations was used to revel the binding mode and the drug resistance of the EVG ligand in E92Q/N155H. Several important interactions were discovered between the mutated residues and the residues in the active site of the E92Q/N155H double mutant pattern, and cross correlation and clustering methods were used for detailed analysis. The results from the MD simulation studies will be used to guide the experimental efforts of developing novel inhibitors against drug-resistant HIV integrase mutants.

Hypoxia- and radiation-inducible, breast cell-specific targeting of retroviral vectors

International Nuclear Information System (INIS)

Lipnik, Karoline; Greco, Olga; Scott, Simon; Knapp, Elzbieta; Mayrhofer, Elisabeth; Rosenfellner, Doris; Guenzburg, Walter H.; Salmons, Brian; Hohenadl, Christine

2006-01-01

To facilitate a more efficient radiation and chemotherapy of mammary tumours, synthetic enhancer elements responsive to hypoxia and ionizing radiation were coupled to the mammary-specific minimal promoter of the murine whey acidic protein (WAP) encoding gene. The modified WAP promoter was introduced into a retroviral promoter conversion (ProCon) vector. Expression of a transduced reporter gene in response to hypoxia and radiation was analysed in stably infected mammary cancer cell lines and an up to 9-fold increase in gene expression demonstrated in comparison to the respective basic vector. Expression analyses in vitro, moreover, demonstrated a widely preserved mammary cell-specific promoter activity. For in vivo analyses, xenograft tumours consisting of infected human mammary adenocarcinoma cells were established in SCID/beige mice. Immunohistochemical analyses demonstrated a hypoxia-specific, markedly increased WAP promoter-driven expression in these tumours. Thus, this retroviral vector will facilitate a targeted gene therapeutic approach exploiting the unique environmental condition in solid tumours

Primary resistance to integrase strand transfer inhibitors in patients infected with diverse HIV-1 subtypes in sub-Saharan Africa

NARCIS (Netherlands)

Inzaule, Seth C.; Hamers, Raph L.; Noguera-Julian, Marc; Casadellà, Maria; Parera, Mariona; Rinke de Wit, Tobias F.; Paredes, Roger

2018-01-01

To investigate the prevalence and patterns of major and accessory resistance mutations associated with integrase strand transfer inhibitors (INSTIs), across diverse HIV-1 subtypes in sub-Saharan Africa. pol gene sequences were obtained using Illumina next-generation sequencing from 425 INSTI-naive

Manifestações otoneurológicas associadas à terapia anti-retroviral Otoneurological manifestations associated with antiretroviral therapy

Directory of Open Access Journals (Sweden)

Andrêza Batista Cheloni Vieira

2008-02-01

Full Text Available Ototoxicidade e terapia anti-retroviral parecem estar associadas. O objetivo desse estudo foi avaliar essa possível correlação. Foram avaliados 779 prontuários médicos de pacientes infectados pelo HIV e regularmente acompanhados, sendo 162 tratados com terapia anti-retroviral e 122 não tratados (controle. Pacientes em tratamento eram mais velhos (média 42 anos, com maior tempo de confirmação sorológica (80 meses e com menor carga viral (p=0,00. CD4+ foi semelhante entre os grupos (P=0,60. No grupo tratado, três (1,8% casos de perda auditiva idiopática e dois (1,3% de perda auditiva relacionada a otosclerose foram observadas e ambas iniciadas após terapia anti-retroviral. Nenhuma diferença estatística relacionada à perda auditiva idiopática foi encontrada entre os grupos. Enquanto estudos descritivos consideram possível ototoxidade associada à terapia anti-retroviral, esse possível efeito adverso não foi relacionado à terapia anti-retroviral neste estudo. Contrariamente, otosclerose poderia estar correlacionada à terapia anti-retroviral. Este assunto merece ser estudado.Ototoxicity and antiretroviral therapy seem to be associated. The aim of this study was to evaluate this possible correlation. Evaluations were carried out on 779 medical records from HIV-infected patients who were being regularly followed up, of whom 162 were being treated with antiretroviral therapy and 122 were untreated (controls. The patients undergoing treatment were older (mean: 42 years, had had serological confirmation for longer times (80 months and had smaller viral loads (P = 0.00. CD4+ was similar between the groups (P = 0.60. In the treated group, three cases (1.8% of idiopathic hearing loss and two (1.3% of otosclerosis-related hearing loss were observed, which both started after antiretroviral therapy. No statistical difference relating to idiopathic hearing loss was found between the groups. While descriptive studies consider possible

Molecular evolution of the insect chemoreceptor gene superfamily in Drosophila melanogaster

Science.gov (United States)

Robertson, Hugh M.; Warr, Coral G.; Carlson, John R.

2003-01-01

The insect chemoreceptor superfamily in Drosophila melanogaster is predicted to consist of 62 odorant receptor (Or) and 68 gustatory receptor (Gr) proteins, encoded by families of 60 Or and 60 Gr genes through alternative splicing. We include two previously undescribed Or genes and two previously undescribed Gr genes; two previously predicted Or genes are shown to be alternative splice forms. Three polymorphic pseudogenes and one highly defective pseudogene are recognized. Phylogenetic analysis reveals deep branches connecting multiple highly divergent clades within the Gr family, and the Or family appears to be a single highly expanded lineage within the superfamily. The genes are spread throughout the Drosophila genome, with some relatively recently diverged genes still clustered in the genome. The Gr5a gene on the X chromosome, which encodes a receptor for the sugar trehalose, has transposed from one such tandem cluster of six genes at cytological location 64, as has Gr61a, and all eight of these receptors might bind sugars. Analysis of intron evolution suggests that the common ancestor consisted of a long N-terminal exon encoding transmembrane domains 1-5 followed by three exons encoding transmembrane domains 6-7. As many as 57 additional introns have been acquired idiosyncratically during the evolution of the superfamily, whereas the ancestral introns and some of the older idiosyncratic introns have been lost at least 48 times independently. Altogether, these patterns of molecular evolution suggest that this is an ancient superfamily of chemoreceptors, probably dating back at least to the origin of the arthropods. PMID:14608037

BF integrase genes of HIV-1 circulating in São Paulo, Brazil, with a recurrent recombination region.

Directory of Open Access Journals (Sweden)

Atila Iamarino

Full Text Available Although some studies have shown diversity in HIV integrase (IN genes, none has focused particularly on the gene evolving in epidemics in the context of recombination. The IN gene in 157 HIV-1 integrase inhibitor-naïve patients from the São Paulo State, Brazil, were sequenced tallying 128 of subtype B (23 of which were found in non-B genomes, 17 of subtype F (8 of which were found in recombinant genomes, 11 integrases were BF recombinants, and 1 from subtype C. Crucially, we found that 4 BF recombinant viruses shared a recurrent recombination breakpoint region between positions 4900 and 4924 (relative to the HXB2 that includes 2 gRNA loops, where the RT may stutter. Since these recombinants had independent phylogenetic origin, we argue that these results suggest a possible recombination hotspot not observed so far in BF CRF in particular, or in any other HIV-1 CRF in general. Additionally, 40% of the drug-naïve and 45% of the drug-treated patients had at least 1 raltegravir (RAL or elvitegravir (EVG resistance-associated amino acid change, but no major resistance mutations were found, in line with other studies. Importantly, V151I was the most common minor resistance mutation among B, F, and BF IN genes. Most codon sites of the IN genes had higher rates of synonymous substitutions (dS indicative of a strong negative selection. Nevertheless, several codon sites mainly in the subtype B were found under positive selection. Consequently, we observed a higher genetic diversity in the B portions of the mosaics, possibly due to the more recent introduction of subtype F on top of an ongoing subtype B epidemics and a fast spread of subtype F alleles among the B population.

The endogenous retroviral insertion in the human complement C4 gene modulates the expression of homologous genes by antisense inhibition.

Science.gov (United States)

Schneider, P M; Witzel-Schlömp, K; Rittner, C; Zhang, L

2001-02-01

Intron 9 contains the complete endogenous retrovirus HERV-K(C4) as a 6.4-kb insertion in 60% of human C4 genes. The retroviral insertion is in reverse orientation to the C4 coding sequence. Therefore, expression of C4 could lead to the transcription of an antisense RNA, which might protect against exogenous retroviral infections. To test this hypothesis, open reading frames from the HERV sequence were subcloned in sense orientiation into a vector allowing expression of a beta-galactosidase fusion protein. Mouse L cells which had been stably transfected with either the human C4A or C4B gene both carrying the HERV insertion (LC4 cells), and L(Tk-) cells without the C4 gene were transiently transfected either with a retroviral construct or with the wild-type vector. Expression was monitored using an enzymatic assay. We demonstrated that (1) HERV-K(C4) antisense mRNA transcripts are present in cells constitutively expressing C4, (2) expression of retroviral-like constructs is significantly downregulated in cells expressing C4, and (3) this downregulation is further modulated in a dose-dependent fashion following interferon-gamma stimulation of C4 expression. These results support the hypothesis of a genomic antisense strategy mediated by the HERV-K(C4) insertion as a possible defense mechanism against exogenous retroviral infections.

Rapid transcriptional pulsing dynamics of high expressing retroviral transgenes in embryonic stem cells.

Directory of Open Access Journals (Sweden)

Mandy Y M Lo

Full Text Available Single cell imaging studies suggest that transcription is not continuous and occurs as discrete pulses of gene activity. To study mechanisms by which retroviral transgenes can transcribe to high levels, we used the MS2 system to visualize transcriptional dynamics of high expressing proviral integration sites in embryonic stem (ES cells. We established two ES cell lines each bearing a single copy, self-inactivating retroviral vector with a strong ubiquitous human EF1α gene promoter directing expression of mRFP fused to an MS2-stem-loop array. Transfection of MS2-EGFP generated EGFP focal dots bound to the mRFP-MS2 stem loop mRNA. These transcription foci colocalized with the transgene integration site detected by immunoFISH. Live tracking of single cells for 20 minutes detected EGFP focal dots that displayed frequent and rapid fluctuations in transcription over periods as short as 25 seconds. Similarly rapid fluctuations were detected from focal doublet signals that colocalized with replicated proviral integration sites by immunoFISH, consistent with transcriptional pulses from sister chromatids. We concluded that retroviral transgenes experience rapid transcriptional pulses in clonal ES cell lines that exhibit high level expression. These events are directed by a constitutive housekeeping gene promoter and may provide precedence for rapid transcriptional pulsing at endogenous genes in mammalian stem cells.

D77, one benzoic acid derivative, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular LEDGF/p75

International Nuclear Information System (INIS)

Du Li; Zhao Yaxue; Chen, Jing; Yang Liumeng; Zheng Yongtang; Tang Yun; Shen Xu; Jiang Hualiang

2008-01-01

Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-factor for integration. Since LEDGF/p75 plays an important role in HIV integration, disruption of the LEDGF/p75 interaction with IN has provided a special interest for anti-HIV agent discovery. In this work, we reported that a benzoic acid derivative, 4-[(5-bromo-4-{[2,4-dioxo-3-(2-oxo-2-phenylethyl) -1,3-thiazolidin-5-ylidene]methyl}-2-ethoxyphenoxy)methyl]benzoic acid (D77) could potently inhibit the IN-LEDGF/p75 interaction and affect the HIV-1 IN nuclear distribution thus exhibiting antiretroviral activity. Molecular docking with site-directed mutagenesis analysis and surface plasmon resonance (SPR) binding assays has clarified possible binding mode of D77 against HIV-1 integrase. As the firstly discovered small molecular compound targeting HIV-1 integrase interaction with LEDGF/p75, D77 might supply useful structural information for further anti-HIV agent discovery

Discovery and optimization of 2-pyridinone aminal integrase strand transfer inhibitors for the treatment of HIV.

Science.gov (United States)

Schreier, John D; Embrey, Mark W; Raheem, Izzat T; Barbe, Guillaume; Campeau, Louis-Charles; Dubost, David; McCabe Dunn, Jamie; Grobler, Jay; Hartingh, Timothy J; Hazuda, Daria J; Klein, Daniel; Miller, Michael D; Moore, Keith P; Nguyen, Natalie; Pajkovic, Natasa; Powell, David A; Rada, Vanessa; Sanders, John M; Sisko, John; Steele, Thomas G; Wai, John; Walji, Abbas; Xu, Min; Coleman, Paul J

2017-05-01

HIV integrase strand transfer inhibitors (InSTIs) represent an important class of antiviral therapeutics with proven efficacy and excellent tolerability for the treatment of HIV infections. In 2007, Raltegravir became the first marketed strand transfer inhibitor pioneering the way to a first-line therapy for treatment-naïve patients. Challenges with this class of therapeutics remain, including frequency of the dosing regimen and the genetic barrier to resistance. To address these issues, research towards next-generation integrase inhibitors has focused on imparting potency against RAL-resistent mutants and improving pharmacokinetic profiles. Herein, we detail medicinal chemistry efforts on a novel class of 2-pyridinone aminal InSTIs, inpsired by MK-0536, which led to the discovery of important lead molecules for our program. Systematic optimization carried out at the amide and aminal positions on the periphery of the core provided the necessary balance of antiviral activity and physiochemical properties. These efforts led to a novel aminal lead compound with the desired virological profile and preclinical pharmacokinetic profile to support a once-daily human dose prediction. Copyright © 2017 Elsevier Ltd. All rights reserved.

New O-superfamily conotoxins from Conus striatus inhabited near Chinese Hainan Island

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

Conotoxins are short peptide-toxins with specific targets and large diversity.They are useful in analgesia,neuroprotection,detection of some kinds of deseases,and receptor and ion channel study.In order to explore the conotoxin resourses of Chinese oceans,rapid amplification of 3' cDNA ends (RACE) method was utilized to systemically analyze the O-superfamily conotoxin content of Conus striatus inhabited near Chinese Hainan Island.Six new O-superfamily conopeptides were identified,one of which is highly homologous to MVIIA,an N-type calcium channel antagonist.

Association of murine lupus and thymic full-length endogenous retroviral expression maps to a bone marrow stem cell

International Nuclear Information System (INIS)

Krieg, A.M.; Gourley, M.F.; Steinberg, A.D.

1991-01-01

Recent studies of thymic gene expression in murine lupus have demonstrated 8.4-kb (full-length size) modified polytropic (Mpmv) endogenous retroviral RNA. In contrast, normal control mouse strains do not produce detectable amounts of such RNA in their thymuses. Prior studies have attributed a defect in experimental tolerance in murine lupus to a bone marrow stem cell rather than to the thymic epithelium; in contrast, infectious retroviral expression has been associated with the thymic epithelium, rather than with the bone marrow stem cell. The present study was designed to determine whether the abnormal Mpmv expression associated with murine lupus mapped to thymic epithelium or to a marrow precursor. Lethally irradiated control and lupus-prone mice were reconstituted with T cell depleted bone marrow; one month later their thymuses were studied for endogenous retroviral RNA and protein expression. Recipients of bone marrow from nonautoimmune donors expressed neither 8.4-kb Mpmv RNA nor surface MCF gp70 in their thymuses. In contrast, recipients of bone marrow from autoimmune NZB or BXSB donors expressed thymic 8.4-kb Mpmv RNA and mink cell focus-forming gp70. These studies demonstrate that lupus-associated 8.4-kb Mpmv endogenous retroviral expression is determined by bone marrow stem cells

Bacterial Multidrug Efflux Pumps of the Major Facilitator Superfamily as Targets for Modulation.

Science.gov (United States)

Kumar, Sanath; He, Guixin; Kakarla, Prathusha; Shrestha, Ugina; Ranjana, K C; Ranaweera, Indrika; Willmon, T Mark; Barr, Sharla R; Hernandez, Alberto J; Varela, Manuel F

2016-01-01

Causative agents of infectious disease that are multidrug resistant bacterial pathogens represent a serious public health concern due to the increasingly difficult nature of achieving efficacious clinical treatments. Of the various acquired and intrinsic antimicrobial agent resistance determinants, integral-membrane multidrug efflux pumps of the major facilitator superfamily constitute a major mechanism of bacterial resistance. The major facilitator superfamily (MFS) encompasses thousands of known related secondary active and passive solute transporters, including multidrug efflux pumps, from bacteria to humans. This review article addresses recent developments involving the targeting by various modulators of bacterial multidrug efflux pumps from the major facilitator superfamily. It is currently of tremendous interest to modulate bacterial multidrug efflux pumps in order to eventually restore the clinical efficacy of therapeutic agents against recalcitrant bacterial infections. Such MFS multidrug efflux pumps are good targets for modulation.

Transcriptional Silencing of Retroviral Vectors

DEFF Research Database (Denmark)

Lund, Anders Henrik; Duch, M.; Pedersen, F.S.

1996-01-01

. Extinction of long-term vector expression has been observed after implantation of transduced hematopoietic cells as well as fibroblasts, myoblasts and hepatocytes. Here we review the influence of vector structure, integration site and cell type on transcriptional silencing. While down-regulation of proviral...... transcription is known from a number of cellular and animal models, major insight has been gained from studies in the germ line and embryonal cells of the mouse. Key elements for the transfer and expression of retroviral vectors, such as the viral transcriptional enhancer and the binding site for the t......RNA primer for reverse transcription may have a major influence on transcriptional silencing. Alterations of these elements of the vector backbone as well as the use of internal promoter elements from housekeeping genes may contribute to reduce transcriptional silencing. The use of cell culture and animal...

[Mechanisms of retroviral immunosuppressive domain-induced immune modulation].

Science.gov (United States)

Blinov, V M; Krasnov, G S; Shargunov, A V; Shurdov, M A; Zverev, V V

2013-01-01

Immunosuppressive domains (ISD) of viral envelope glycoproteins provide highly pathogenic phenotypes of various retroviruses. ISD interaction with immune cells leads to an inhibition of a response. In the 1980s it was shown that the fragment of ISD comprising of 17 amino acids (named CKS-17) is carrying out such immune modulation. However the underlying mechanisms were not known. The years of thorough research allowed to identify the regulation of Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR cellular pathways as a result of ISD interaction with immune cells. By the way, this leads to decrease of secretion of stimulatory cytokines (e.g., IL-12) and increase of inhibitory, anti-inflammatory ones (e.g., IL-10). One of the receptor tyrosine kinases inducing signal in these pathways acts as the primary target of ISD while other key regulators--cAMP and diacylglycerol (DAG), act as secondary messengers of signal transduction. Immunosuppressive-like domains can be found not only in retroviruses; the presence of ISD within Ebola viral envelope glycoproteins caused extremely hard clinical course of virus-induced hemorrhagic fever. A number of retroviral-origin fragments encoding ISD can be found in the human genome. These regions are expressed in the placenta within genes of syncytins providing a tolerance of mother's immune system to an embryo. The present review is devoted to molecular aspects of retroviral ISD-induced modulation of host immune system.

Nuclear Receptors in atherosclerosis: a superfamily with many 'Goodfellas'

NARCIS (Netherlands)

Kurakula, Kondababu; Hamers, Anouk A. J.; de Waard, Vivian; de Vries, Carlie J. M.

2013-01-01

Nuclear Receptors form a superfamily of 48 transcription factors that exhibit a plethora of functions in steroid hormone signaling, regulation of metabolism, circadian rhythm and cellular differentiation. In this review, we describe our current knowledge on the role of Nuclear Receptors in

Relationship between Apolipoprotein Superfamily and Parkinson's Disease

Directory of Open Access Journals (Sweden)

Lin Li

2017-01-01

Conclusions: The Apo superfamily has been proved to be closely involved in the initiation, progression, and prognosis of PD. Apos and their genes are of great value in predicting the susceptibility of PD and hopeful to become the target of medical intervention to prevent the onset of PD or slow down the progress. Therefore, further large-scale studies are warranted to elucidate the precise mechanisms of Apos in PD.

Expression of cDNAs in human Natural Killer cell lines by retroviral transduction.

Science.gov (United States)

Miah, S M Shahjahan; Campbell, Kerry S

2010-01-01

Human NK-like cell lines are difficult to transfect using standard mammalian expression vectors and conventional transfection protocols, but they are susceptible to retroviral transduction as a means to introduce cDNAs. Our laboratory has exploited this technique to study a number of receptors in human NK cell lines. The method utilizes a bicistronic retroviral vector that co-expresses either drug resistance or enhanced green fluorescent protein (EGFP) in parallel with the gene of interest. After a single infection with recombinant retrovirus, transduced NK cells can be sorted for expression of EGFP or the transduced cell surface marker. Alternatively, cells expressing the transduced cDNAs can be selected for by treatment with neomycin, puromycin, or hygromycin. Using this method, the sorted/selected cells uniformly express the gene of interest and the expression is stable for many weeks of culture.

In vivo mitochondrial function in HIV-infected persons treated with contemporary anti-retroviral therapy: a magnetic resonance spectroscopy study.

Directory of Open Access Journals (Sweden)

Brendan A I Payne

Full Text Available Modern anti-retroviral therapy is highly effective at suppressing viral replication and restoring immune function in HIV-infected persons. However, such individuals show reduced physiological performance and increased frailty compared with age-matched uninfected persons. Contemporary anti-retroviral therapy is thought to be largely free from neuromuscular complications, whereas several anti-retroviral drugs previously in common usage have been associated with mitochondrial toxicity. It has recently been established that patients with prior exposure to such drugs exhibit irreversible cellular and molecular mitochondrial defects. However the functional significance of such damage remains unknown. Here we use phosphorus magnetic resonance spectroscopy ((31P-MRS to measure in vivo muscle mitochondrial oxidative function, in patients treated with contemporary anti-retroviral therapy, and compare with biopsy findings (cytochrome c oxidase (COX histochemistry. We show that dynamic oxidative function (post-exertional ATP (adenosine triphosphate resynthesis was largely maintained in the face of mild to moderate COX defects (affecting up to ∼10% of fibers: τ½ ADP (half-life of adenosine diphosphate clearance, HIV-infected 22.1±9.9 s, HIV-uninfected 18.8±4.4 s, p = 0.09. In contrast, HIV-infected patients had a significant derangement of resting state ATP metabolism compared with controls: ADP/ATP ratio, HIV-infected 1.24±0.08×10(-3, HIV-uninfected 1.16±0.05×10(-3, p = 0.001. These observations are broadly reassuring in that they suggest that in vivo mitochondrial function in patients on contemporary anti-retroviral therapy is largely maintained at the whole organ level, despite histochemical (COX defects within individual cells. Basal energy requirements may nevertheless be increased.

In silico identification, phylogeny and expression analysis of expansin superfamily in Medicago truncatula

Directory of Open Access Journals (Sweden)

Ying Liu

2016-01-01

Full Text Available Expansins are important components of plant cell walls, which are involved in the process of cell wall loosening under low extracellular pH. By using a combinational method for homology search and protein domain analysis, a total of 42 expansin genes were identified from Medicago truncatula genome in this study. They were divided into four families, based on sequence alignment and phylogenetic analysis. Gene duplication events were identified in the expansins superfamily, especially in the extension of α-expansin family. By analysis of RNA-sequencing data from National Center for Biotechnology Information, the expansin (EXP genes expressed during tissues development were characterized. Meanwhile, lots of cis-acting regulatory DNA elements in the EXP superfamily were identified, which were mainly related to plant growth and development processes. The results presented in this study are expected to facilitate further research works on this gene superfamily and provide new insights about the molecular mechanisms of expansins in M. truncatula.

Fragment Based Strategies for Discovery of Novel HIV-1 Reverse Transcriptase and Integrase Inhibitors.

Science.gov (United States)

Latham, Catherine F; La, Jennifer; Tinetti, Ricky N; Chalmers, David K; Tachedjian, Gilda

2016-01-01

Human immunodeficiency virus (HIV) remains a global health problem. While combined antiretroviral therapy has been successful in controlling the virus in patients, HIV can develop resistance to drugs used for treatment, rendering available drugs less effective and limiting treatment options. Initiatives to find novel drugs for HIV treatment are ongoing, although traditional drug design approaches often focus on known binding sites for inhibition of established drug targets like reverse transcriptase and integrase. These approaches tend towards generating more inhibitors in the same drug classes already used in the clinic. Lack of diversity in antiretroviral drug classes can result in limited treatment options, as cross-resistance can emerge to a whole drug class in patients treated with only one drug from that class. A fresh approach in the search for new HIV-1 drugs is fragment-based drug discovery (FBDD), a validated strategy for drug discovery based on using smaller libraries of low molecular weight molecules (FBDD is aimed at not only finding novel drug scaffolds, but also probing the target protein to find new, often allosteric, inhibitory binding sites. Several fragment-based strategies have been successful in identifying novel inhibitory sites or scaffolds for two proven drug targets for HIV-1, reverse transcriptase and integrase. While any FBDD-generated HIV-1 drugs have yet to enter the clinic, recent FBDD initiatives against these two well-characterised HIV-1 targets have reinvigorated antiretroviral drug discovery and the search for novel classes of HIV-1 drugs.

Self-Assembly in the Ferritin Nano-Cage Protein Superfamily

Directory of Open Access Journals (Sweden)

Yu Zhang

2011-08-01

Full Text Available Protein self-assembly, through specific, high affinity, and geometrically constraining protein-protein interactions, can control and lead to complex cellular nano-structures. Establishing an understanding of the underlying principles that govern protein self-assembly is not only essential to appreciate the fundamental biological functions of these structures, but could also provide a basis for their enhancement for nano-material applications. The ferritins are a superfamily of well studied proteins that self-assemble into hollow cage-like structures which are ubiquitously found in both prokaryotes and eukaryotes. Structural studies have revealed that many members of the ferritin family can self-assemble into nano-cages of two types. Maxi-ferritins form hollow spheres with octahedral symmetry composed of twenty-four monomers. Mini-ferritins, on the other hand, are tetrahedrally symmetric, hollow assemblies composed of twelve monomers. This review will focus on the structure of members of the ferritin superfamily, the mechanism of ferritin self-assembly and the structure-function relations of these proteins.

Evolution of endogenous non-retroviral genes integrated into plant genomes

Directory of Open Access Journals (Sweden)

Hyosub Chu

2014-08-01

Full Text Available Numerous comparative genome analyses have revealed the wide extent of horizontal gene transfer (HGT in living organisms, which contributes to their evolution and genetic diversity. Viruses play important roles in HGT. Endogenous viral elements (EVEs are defined as viral DNA sequences present within the genomes of non-viral organisms. In eukaryotic cells, the majority of EVEs are derived from RNA viruses using reverse transcription. In contrast, endogenous non-retroviral elements (ENREs are poorly studied. However, the increasing availability of genomic data and the rapid development of bioinformatics tools have enabled the identification of several ENREs in various eukaryotic organisms. To date, a small number of ENREs integrated into plant genomes have been identified. Of the known non-retroviruses, most identified ENREs are derived from double-strand (ds RNA viruses, followed by single-strand (ss DNA and ssRNA viruses. At least eight virus families have been identified. Of these, viruses in the family Partitiviridae are dominant, followed by viruses of the families Chrysoviridae and Geminiviridae. The identified ENREs have been primarily identified in eudicots, followed by monocots. In this review, we briefly discuss the current view on non-retroviral sequences integrated into plant genomes that are associated with plant-virus evolution and their possible roles in antiviral resistance.

VlincRNAs controlled by retroviral elements are a hallmark of pluripotency and cancer.

Science.gov (United States)

St Laurent, Georges; Shtokalo, Dmitry; Dong, Biao; Tackett, Michael R; Fan, Xiaoxuan; Lazorthes, Sandra; Nicolas, Estelle; Sang, Nianli; Triche, Timothy J; McCaffrey, Timothy A; Xiao, Weidong; Kapranov, Philipp

2013-07-22

The function of the non-coding portion of the human genome remains one of the most important questions of our time. Its vast complexity is exemplified by the recent identification of an unusual and notable component of the transcriptome - very long intergenic non-coding RNAs, termed vlincRNAs. Here we identify 2,147 vlincRNAs covering 10 percent of our genome. We show they are present not only in cancerous cells, but also in primary cells and normal human tissues, and are controlled by canonical promoters. Furthermore, vlincRNA promoters frequently originate from within endogenous retroviral sequences. Strikingly, the number of vlincRNAs expressed from endogenous retroviral promoters strongly correlates with pluripotency or the degree of malignant transformation. These results suggest a previously unknown connection between the pluripotent state and cancer via retroviral repeat-driven expression of vlincRNAs. Finally, we show that vlincRNAs can be syntenically conserved in humans and mouse and their depletion using RNAi can cause apoptosis in cancerous cells. These intriguing observations suggest that vlincRNAs could create a framework that combines many existing short ESTs and lincRNAs into a landscape of very long transcripts functioning in the regulation of gene expression in the nucleus. Certain types of vlincRNAs participate at specific stages of normal development and, based on analysis of a limited set of cancerous and primary cell lines, they appear to be co-opted by cancer-associated transcriptional programs. This provides additional understanding of transcriptome regulation during the malignant state, and could lead to additional targets and options for its reversal.

The prion protein has DNA strand transfer properties similar to retroviral nucleocapsid protein.

Science.gov (United States)

Gabus, C; Auxilien, S; Péchoux, C; Dormont, D; Swietnicki, W; Morillas, M; Surewicz, W; Nandi, P; Darlix, J L

2001-04-06

The transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are associated with the accumulation of a protease-resistant form of the cellular prion protein (PrP). Although PrP is highly conserved and widely expressed in vertebrates, its function remains a matter of speculation. Indeed PrP null mice develop normally and are healthy. Recent results show that PrP binds to nucleic acids in vitro and is found associated with retroviral particles. Furthermore, in mice the scrapie infectious process appears to be accelerated by MuLV replication. These observations prompted us to further investigate the interaction between PrP and nucleic acids, and compare it with that of the retroviral nucleocapsid protein (NC). As the major nucleic acid-binding protein of the retroviral particle, NC protein is tightly associated with the genomic RNA in the virion nucleocapsid, where it chaperones proviral DNA synthesis by reverse transcriptase. Our results show that the human prion protein (huPrP) functionally resembles NCp7 of HIV-1. Both proteins form large nucleoprotein complexes upon binding to DNA. They accelerate the hybridization of complementary DNA strands and chaperone viral DNA synthesis during the minus and plus DNA strand transfers necessary to generate the long terminal repeats. The DNA-binding and strand transfer properties of huPrP appear to map to the N-terminal fragment comprising residues 23 to 144, whereas the C-terminal domain is inactive. These findings suggest that PrP could be involved in nucleic acid metabolism in vivo. Copyright 2001 Academic Press.

High-definition mapping of retroviral integration sites defines the fate of allogeneic T cells after donor lymphocyte infusion.

Directory of Open Access Journals (Sweden)

Claudia Cattoglio

2010-12-01

Full Text Available The infusion of donor lymphocytes transduced with a retroviral vector expressing the HSV-TK suicide gene in patients undergoing hematopoietic stem cell transplantation for leukemia/lymphoma promotes immune reconstitution and prevents infections and graft-versus-host disease. Analysis of the clonal dynamics of genetically modified lymphocytes in vivo is of crucial importance to understand the potential genotoxic risk of this therapeutic approach. We used linear amplification-mediated PCR and pyrosequencing to build a genome-wide, high-definition map of retroviral integration sites in the genome of peripheral blood T cells from two different donors and used gene expression profiling and bioinformatics to associate integration clusters to transcriptional activity and to genetic and epigenetic features of the T cell genome. Comparison with matched random controls and with integrations obtained from CD34(+ hematopoietic stem/progenitor cells showed that integration clusters occur within chromatin regions bearing epigenetic marks associated with active promoters and regulatory elements in a cell-specific fashion. Analysis of integration sites in T cells obtained ex vivo two months after infusion showed no evidence of integration-related clonal expansion or dominance, but rather loss of cells harboring integration events interfering with RNA post-transcriptional processing. The study shows that high-definition maps of retroviral integration sites are a powerful tool to analyze the fate of genetically modified T cells in patients and the biological consequences of retroviral transduction.

Evolutionary history, structural features and biochemical diversity of the NlpC/P60 superfamily of enzymes.

Science.gov (United States)

Anantharaman, Vivek; Aravind, L

2003-01-01

Peptidoglycan is hydrolyzed by a diverse set of enzymes during bacterial growth, development and cell division. The N1pC/P60 proteins define a family of cell-wall peptidases that are widely represented in various bacterial lineages. Currently characterized members are known to hydrolyze D-gamma-glutamyl-meso-diaminopimelate or N-acetylmuramate-L-alanine linkages. Detailed analysis of the N1pC/P60 peptidases showed that these proteins define a large superfamily encompassing several diverse groups of proteins. In addition to the well characterized P60-like proteins, this superfamily includes the AcmB/LytN and YaeF/YiiX families of bacterial proteins, the amidase domain of bacterial and kinetoplastid glutathionylspermidine synthases (GSPSs), and several proteins from eukaryotes, phages, poxviruses, positive-strand RNA viruses, and certain archaea. The eukaryotic members include lecithin retinol acyltransferase (LRAT), nematode developmental regulator Egl-26, and candidate tumor suppressor H-rev107. These eukaryotic proteins, along with the bacterial YaeF/poxviral G6R family, show a circular permutation of the catalytic domain. We identified three conserved residues, namely a cysteine, a histidine and a polar residue, that are involved in the catalytic activities of this superfamily. Evolutionary analysis of this superfamily shows that it comprises four major families, with diverse domain architectures in each of them. Several related, but distinct, catalytic activities, such as murein degradation, acyl transfer and amide hydrolysis, have emerged in the N1pC/P60 superfamily. The three conserved catalytic residues of this superfamily are shown to be equivalent to the catalytic triad of the papain-like thiol peptidases. The predicted structural features indicate that the N1pC/P60 enzymes contain a fold similar to the papain-like peptidases, transglutaminases and arylamine acetyltransferases.

Study of Structure-active Relationship for Inhibitors of HIV-1 Integrase LEDGF/p75 Interaction by Machine Learning Methods.

Science.gov (United States)

Li, Yang; Wu, Yanbin; Yan, Aixia

2017-07-01

HIV-1 integrase (IN) is a promising target for anti-AIDS therapy, and LEDGF/p75 is proved to enhance the HIV-1 integrase strand transfer activity in vitro. Blocking the interaction between IN and LEDGF/p75 is an effective way to inhibit HIV replication infection. In this work, 274 LEDGF/p75-IN inhibitors were collected as the dataset. Support Vector Machine (SVM), Decision Tree (DT), Function Tree (FT) and Random Forest (RF) were applied to build several computational models for predicting whether a compound is an active or weakly active LEDGF/p75-IN inhibitor. Each compound is represented by MACCS fingerprints and CORINA Symphony descriptors. The prediction accuracies for the test sets of all the models are over 70 %. The best model Model 3B built by FT obtained a prediction accuracy and a Matthews Correlation Coefficient (MCC) of 81.08 % and 0.62 on test set, respectively. We found that the hydrogen bond and hydrophobic interactions are important for the bioactivity of an inhibitor. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

External pH modulates EAG superfamily K+ channels through EAG-specific acidic residues in the voltage sensor

Science.gov (United States)

Kazmierczak, Marcin; Zhang, Xiaofei; Chen, Bihan; Mulkey, Daniel K.; Shi, Yingtang; Wagner, Paul G.; Pivaroff-Ward, Kendra; Sassic, Jessica K.; Bayliss, Douglas A.

2013-01-01

The Ether-a-go-go (EAG) superfamily of voltage-gated K+ channels consists of three functionally distinct gene families (Eag, Elk, and Erg) encoding a diverse set of low-threshold K+ currents that regulate excitability in neurons and muscle. Previous studies indicate that external acidification inhibits activation of three EAG superfamily K+ channels, Kv10.1 (Eag1), Kv11.1 (Erg1), and Kv12.1 (Elk1). We show here that Kv10.2, Kv12.2, and Kv12.3 are similarly inhibited by external protons, suggesting that high sensitivity to physiological pH changes is a general property of EAG superfamily channels. External acidification depolarizes the conductance–voltage (GV) curves of these channels, reducing low threshold activation. We explored the mechanism of this high pH sensitivity in Kv12.1, Kv10.2, and Kv11.1. We first examined the role of acidic voltage sensor residues that mediate divalent cation block of voltage activation in EAG superfamily channels because protons reduce the sensitivity of Kv12.1 to Zn2+. Low pH similarly reduces Mg2+ sensitivity of Kv10.1, and we found that the pH sensitivity of Kv11.1 was greatly attenuated at 1 mM Ca2+. Individual neutralizations of a pair of EAG-specific acidic residues that have previously been implicated in divalent block of diverse EAG superfamily channels greatly reduced the pH response in Kv12.1, Kv10.2, and Kv11.1. Our results therefore suggest a common mechanism for pH-sensitive voltage activation in EAG superfamily channels. The EAG-specific acidic residues may form the proton-binding site or alternatively are required to hold the voltage sensor in a pH-sensitive conformation. The high pH sensitivity of EAG superfamily channels suggests that they could contribute to pH-sensitive K+ currents observed in vivo. PMID:23712551

External pH modulates EAG superfamily K+ channels through EAG-specific acidic residues in the voltage sensor.

Science.gov (United States)

Kazmierczak, Marcin; Zhang, Xiaofei; Chen, Bihan; Mulkey, Daniel K; Shi, Yingtang; Wagner, Paul G; Pivaroff-Ward, Kendra; Sassic, Jessica K; Bayliss, Douglas A; Jegla, Timothy

2013-06-01

The Ether-a-go-go (EAG) superfamily of voltage-gated K(+) channels consists of three functionally distinct gene families (Eag, Elk, and Erg) encoding a diverse set of low-threshold K(+) currents that regulate excitability in neurons and muscle. Previous studies indicate that external acidification inhibits activation of three EAG superfamily K(+) channels, Kv10.1 (Eag1), Kv11.1 (Erg1), and Kv12.1 (Elk1). We show here that Kv10.2, Kv12.2, and Kv12.3 are similarly inhibited by external protons, suggesting that high sensitivity to physiological pH changes is a general property of EAG superfamily channels. External acidification depolarizes the conductance-voltage (GV) curves of these channels, reducing low threshold activation. We explored the mechanism of this high pH sensitivity in Kv12.1, Kv10.2, and Kv11.1. We first examined the role of acidic voltage sensor residues that mediate divalent cation block of voltage activation in EAG superfamily channels because protons reduce the sensitivity of Kv12.1 to Zn(2+). Low pH similarly reduces Mg(2+) sensitivity of Kv10.1, and we found that the pH sensitivity of Kv11.1 was greatly attenuated at 1 mM Ca(2+). Individual neutralizations of a pair of EAG-specific acidic residues that have previously been implicated in divalent block of diverse EAG superfamily channels greatly reduced the pH response in Kv12.1, Kv10.2, and Kv11.1. Our results therefore suggest a common mechanism for pH-sensitive voltage activation in EAG superfamily channels. The EAG-specific acidic residues may form the proton-binding site or alternatively are required to hold the voltage sensor in a pH-sensitive conformation. The high pH sensitivity of EAG superfamily channels suggests that they could contribute to pH-sensitive K(+) currents observed in vivo.

Murine leukemia viruses: objects and organisms.

Science.gov (United States)

Rein, Alan

2011-01-01

Murine leukemia viruses (MLVs) are among the simplest retroviruses. Prototypical gammaretroviruses encode only the three polyproteins that will be used in the assembly of progeny virus particles. These are the Gag polyprotein, which is the structural protein of a retrovirus particle, the Pol protein, comprising the three retroviral enzymes-protease, which catalyzes the maturation of the particle, reverse transcriptase, which copies the viral RNA into DNA upon infection of a new host cell, and integrase, which inserts the DNA into the chromosomal DNA of the host cell, and the Env polyprotein, which induces the fusion of the viral membrane with that of the new host cell, initiating infection. In general, a productive MLV infection has no obvious effect upon host cells. Although gammaretroviral structure and replication follow the same broad outlines as those of other retroviruses, we point out a number of significant differences between different retroviral genera.

Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model

Science.gov (United States)

Chatterjee, Aparajita; Ratner, Daniel M.; Ryan, Christopher M.; Johnson, Patricia J.; O’Keefe, Barry R.; Secor, W. Evan; Anderson, Deborah J.; Robbins, Phillips W.; Samuelson, John

2015-01-01

Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans), like those of HIV, bind the mannose-binding lectin (MBL) that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin) and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas. PMID:26252012

Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model.

Directory of Open Access Journals (Sweden)

Aparajita Chatterjee

Full Text Available Trichomonas vaginalis causes vaginitis and increases the risk of HIV transmission by heterosexual sex, while Tritrichomonas foetus causes premature abortion in cattle. Our goals were to determine the effects, if any, of anti-retroviral lectins, which are designed to prevent heterosexual transmission of HIV, on adherence of Trichomonas to ectocervical cells and on Tritrichomonas infections in a mouse model. We show that Trichomonas Asn-linked glycans (N-glycans, like those of HIV, bind the mannose-binding lectin (MBL that is part of the innate immune system. N-glycans of Trichomonas and Tritrichomonas bind anti-retroviral lectins (cyanovirin-N and griffithsin and the 2G12 monoclonal antibody, each of which binds HIV N-glycans. Binding of cyanovirin-N appears to be independent of susceptibility to metronidazole, the major drug used to treat Trichomonas. Anti-retroviral lectins, MBL, and galectin-1 cause Trichomonas to self-aggregate and precipitate. The anti-retroviral lectins also increase adherence of ricin-resistant mutants, which are less adherent than parent cells, to ectocervical cell monolayers and to organotypic EpiVaginal tissue cells. Topical application of either anti-retroviral lectins or yeast N-glycans decreases by 40 to 70% the recovery of Tritrichomonas from the mouse vagina. These results, which are explained by a few simple models, suggest that the anti-retroviral lectins have a modest potential for preventing or treating human infections with Trichomonas.

Exploring and Expanding the Fatty-Acid-Binding Protein Superfamily in Fasciola Species.

Science.gov (United States)

Morphew, Russell M; Wilkinson, Toby J; Mackintosh, Neil; Jahndel, Veronika; Paterson, Steve; McVeigh, Paul; Abbas Abidi, Syed M; Saifullah, Khalid; Raman, Muthusamy; Ravikumar, Gopalakrishnan; LaCourse, James; Maule, Aaron; Brophy, Peter M

2016-09-02

The liver flukes Fasciola hepatica and F. gigantica infect livestock worldwide and threaten food security with climate change and problematic control measures spreading disease. Fascioliasis is also a foodborne disease with up to 17 million humans infected. In the absence of vaccines, treatment depends on triclabendazole (TCBZ), and overuse has led to widespread resistance, compromising future TCBZ control. Reductionist biology from many laboratories has predicted new therapeutic targets. To this end, the fatty-acid-binding protein (FABP) superfamily has proposed multifunctional roles, including functions intersecting vaccine and drug therapy, such as immune modulation and anthelmintic sequestration. Research is hindered by a lack of understanding of the full FABP superfamily complement. Although discovery studies predicted FABPs as promising vaccine candidates, it is unclear if uncharacterized FABPs are more relevant for vaccine formulations. We have coupled genome, transcriptome, and EST data mining with proteomics and phylogenetics to reveal a liver fluke FABP superfamily of seven clades: previously identified clades I-III and newly identified clades IV-VII. All new clade FABPs were analyzed using bioinformatics and cloned from both liver flukes. The extended FABP data set will provide new study tools to research the role of FABPs in parasite biology and as therapy targets.

Removal of bacterial cells, antibiotic resistance genes and integrase genes by on-site hospital wastewater treatment plants: surveillance of treated hospital effluent quality

KAUST Repository

Timraz, Kenda Hussain Hassan; Xiong, Yanghui; Al Qarni, Hamed; Hong, Pei-Ying

2016-01-01

This study aims to evaluate the removal efficiency of microbial contaminants, including total cell counts, antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs, e.g. tetO, tetZ, sul1 and sul2) and integrase genes (e.g. intl1

Functional Diversity of Haloacid Dehalogenase Superfamily Phosphatases from Saccharomyces cerevisiae: BIOCHEMICAL, STRUCTURAL, AND EVOLUTIONARY INSIGHTS.

Science.gov (United States)

Kuznetsova, Ekaterina; Nocek, Boguslaw; Brown, Greg; Makarova, Kira S; Flick, Robert; Wolf, Yuri I; Khusnutdinova, Anna; Evdokimova, Elena; Jin, Ke; Tan, Kemin; Hanson, Andrew D; Hasnain, Ghulam; Zallot, Rémi; de Crécy-Lagard, Valérie; Babu, Mohan; Savchenko, Alexei; Joachimiak, Andrzej; Edwards, Aled M; Koonin, Eugene V; Yakunin, Alexander F

2015-07-24

The haloacid dehalogenase (HAD)-like enzymes comprise a large superfamily of phosphohydrolases present in all organisms. The Saccharomyces cerevisiae genome encodes at least 19 soluble HADs, including 10 uncharacterized proteins. Here, we biochemically characterized 13 yeast phosphatases from the HAD superfamily, which includes both specific and promiscuous enzymes active against various phosphorylated metabolites and peptides with several HADs implicated in detoxification of phosphorylated compounds and pseudouridine. The crystal structures of four yeast HADs provided insight into their active sites, whereas the structure of the YKR070W dimer in complex with substrate revealed a composite substrate-binding site. Although the S. cerevisiae and Escherichia coli HADs share low sequence similarities, the comparison of their substrate profiles revealed seven phosphatases with common preferred substrates. The cluster of secondary substrates supporting significant activity of both S. cerevisiae and E. coli HADs includes 28 common metabolites that appear to represent the pool of potential activities for the evolution of novel HAD phosphatases. Evolution of novel substrate specificities of HAD phosphatases shows no strict correlation with sequence divergence. Thus, evolution of the HAD superfamily combines the conservation of the overall substrate pool and the substrate profiles of some enzymes with remarkable biochemical and structural flexibility of other superfamily members. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Retroviral rebound syndrome after treatment discontinuation in a 15 year old girl with HIV attracted through mother-to-child transmission: case report

OpenAIRE

Gisslén Magnus; Friman Vanda

2007-01-01

Abstract A case of a 15 year old girl with retroviral rebound syndrome after discontinuation of highly active antiretroviral treatment (HAART) due to side effects is presented. The patient was transmitted with HIV at birth by her mother. She had recovered from severe AIDS after HAART was initiated five years earlier. This is the first case reported in the literature of retroviral rebound syndrome in a vertically transmitted HIV-infected patient.

TNF and TNF Receptor Superfamily Members in HIV infection: New Cellular Targets for Therapy?

Directory of Open Access Journals (Sweden)

Amit Kumar

2013-01-01

Full Text Available Tumor necrosis factor (TNF and TNF receptors (TNFR superfamily members are engaged in diverse cellular phenomena such as cellular proliferation, morphogenesis, apoptosis, inflammation, and immune regulation. Their role in regulating viral infections has been well documented. Viruses have evolved with numerous strategies to interfere with TNF-mediated signaling indicating the importance of TNF and TNFR superfamily in viral pathogenesis. Recent research reports suggest that TNF and TNFRs play an important role in the pathogenesis of HIV. TNFR signaling modulates HIV replication and HIV proteins interfere with TNF/TNFR pathways. Since immune activation and inflammation are the hallmark of HIV infection, the use of TNF inhibitors can have significant impact on HIV disease progression. In this review, we will describe how HIV infection is modulated by signaling mediated through members of TNF and TNFR superfamily and in turn how these latter could be targeted by HIV proteins. Finally, we will discuss the emerging therapeutics options based on modulation of TNF activity that could ultimately lead to the cure of HIV-infected patients.

Complementation of a primer binding site-impaired murine leukemia virus-derived retroviral vector by a genetically engineered tRNA-like primer

DEFF Research Database (Denmark)

Lund, Anders Henrik; Duch, M; Lovmand, J

1997-01-01

, but not with a noncomplementary tRNA-like molecule. The engineered primer was shown to be involved in both the initiation of first-strand synthesis and second-strand transfer. These results provide an in vivo demonstration that the retroviral replication machinery may recognize sequence complementarity rather than actual primer...... binding site and 3' primer sequences. Use of mutated primer binding site vectors replicating via engineered primers may add additional control features to retroviral gene transfer technology....

Design and Synthesis of Bis-amide and Hydrazide-containing Derivatives of Malonic Acid as Potential HIV-1 Integrase Inhibitors

Directory of Open Access Journals (Sweden)

Nouri Neamati

2008-10-01

Full Text Available HIV-1 integrase (IN is an attractive and validated target for the development of novel therapeutics against AIDS. In the search for new IN inhibitors, we designed and synthesized three series of bis-amide and hydrazide-containing derivatives of malonic acid. We performed a docking study to investigate the potential interactions of the title compounds with essential amino acids on the IN active site.

6-(1-Benzyl-1H-pyrrol-2-yl)-2,4-dioxo-5-hexenoic acids as dual inhibitors of recombinant HIV-1 integrase and ribonuclease H, synthesized by a parallel synthesis approach.

Science.gov (United States)

Costi, Roberta; Métifiot, Mathieu; Esposito, Francesca; Cuzzucoli Crucitti, Giuliana; Pescatori, Luca; Messore, Antonella; Scipione, Luigi; Tortorella, Silvano; Zinzula, Luca; Novellino, Ettore; Pommier, Yves; Tramontano, Enzo; Marchand, Christophe; Di Santo, Roberto

2013-11-14

The increasing efficiency of HAART has helped to transform HIV/AIDS into a chronic disease. Still, resistance and drug-drug interactions warrant the development of new anti-HIV agents. We previously discovered hit 6, active against HIV-1 replication and targeting RNase H in vitro. Because of its diketo-acid moiety, we speculated that this chemotype could serve to develop dual inhibitors of both RNase H and integrase. Here, we describe a new series of 1-benzyl-pyrrolyl diketohexenoic derivatives, 7a-y and 8a-y, synthesized following a parallel solution-phase approach. Those 50 analogues have been tested on recombinant enzymes (RNase H and integrase) and in cell-based assays. Approximately half (22) exibited inhibition of HIV replication. Compounds 7b, 7u, and 8g were the most active against the RNase H activity of reverse-transcriptase, with IC50 values of 3, 3, and 2.5 μM, respectively. Compound 8g was also the most potent integrase inhibitor with an IC50 value of 26 nM.

A new generation of pPRIG-based retroviral vectors

Directory of Open Access Journals (Sweden)

Boulukos Kim E

2007-11-01

Full Text Available Abstract Background Retroviral vectors are valuable tools for gene transfer. Particularly convenient are IRES-containing retroviral vectors expressing both the protein of interest and a marker protein from a single bicistronic mRNA. This coupled expression increases the relevance of tracking and/or selection of transduced cells based on the detection of a marker protein. pAP2 is a retroviral vector containing eGFP downstream of a modified IRES element of EMCV origin, and a CMV enhancer-promoter instead of the U3 region of the 5'LTR, which increases its efficiency in transient transfection. However, pAP2 contains a limited multicloning site (MCS and shows weak eGFP expression, which previously led us to engineer an improved version, termed pPRIG, harboring: i the wild-type ECMV IRES sequence, thereby restoring its full activity; ii an optimized MCS flanked by T7 and SP6 sequences; and iii a HA tag encoding sequence 5' of the MCS (pPRIG HAa/b/c. Results The convenience of pPRIG makes it a good basic vector to generate additional derivatives for an extended range of use. Here we present several novel pPRIG-based vectors (collectively referred to as PRIGs in which : i the HA tag sequence was inserted in the three reading frames 3' of the MCS (3'HA PRIGs; ii a functional domain (ER, VP16 or KRAB was inserted either 5' or 3' of the MCS (« modular » PRIGs; iii eGFP was replaced by either eCFP, eYFP, mCherry or puro-R (« single color/resistance » PRIGs; and iv mCherry, eYFP or eGFP was inserted 5' of the MCS of the IRES-eGFP, IRES-eCFP or IRES-Puro-R containing PRIGs, respectively (« dual color/selection » PRIGs. Additionally, some of these PRIGs were also constructed in a pMigR MSCV background which has been widely used in pluripotent cells. Conclusion These novel vectors allow for straightforward detection of any expressed protein (3'HA PRIGs, for functional studies of chimeric proteins (« modular » PRIGs, for multiple transductions and

Activities of wildtype and mutant p53 in suppression of homologous recombination as measured by a retroviral vector system

International Nuclear Information System (INIS)

Lu Xiongbin; Lozano, Guillermina; Donehower, Lawrence A.

2003-01-01

DNA repair of double strand breaks, interstrand DNA cross-links, and other types of DNA damage utilizes the processes of homologous recombination and non-homologous end joining to repair the damage. Aberrant homologous recombination is likely to be responsible for a significant fraction of chromosomal deletions, duplications, and translocations that are observed in cancer cells. To facilitate measurement of homologous recombination frequencies in normal cells, mutant cells, and cancer cells, we have developed a high titer retroviral vector containing tandem repeats of mutant versions of a GFP-Zeocin resistance fusion gene and an intact neomycin resistance marker. Recombination between the tandem repeats regenerates a functional GFP-Zeo R marker that can be easily scored. This retroviral vector was used to assess homologous recombination frequencies in human cancer cells and rodent fibroblasts with differing dosages of wild type or mutant p53. Absence of wild type p53 stimulated spontaneous and ionizing radiation-induced homologous recombination, confirming previous studies. Moreover, p53 +/- mouse fibroblasts show elevated levels of homologous recombination compared to their p53 +/+ counterparts following retroviral vector infection, indicating that p53 is haploinsufficient for suppression of homologous recombination. Transfection of vector-containing p53 null Saos-2 cells with various human cancer-associated p53 mutants revealed that these altered p53 proteins retain some recombination suppression function despite being totally inactive for transcriptional transactivation. The retroviral vector utilized in these studies may be useful in performing recombination assays on a wide array of cell types, including those not readily transfected by normal vectors

Queratinocitos humanos modificados genéticamente por medio de un vector retroviral

Directory of Open Access Journals (Sweden)

C. Chamorro

2001-07-01

Full Text Available Los queratinocitos poseen características ideales para la terapia génica: accesibles, modifi-cables por vectores retrovirales, conservan in vitro sus propiedades de proliferación y diferen-ciación, fácil remoción por efectos adversos. Nuestro objetivo fue evaluar estas células comoblanco de transferencia de genes empleando el vector retroviral Foch-29 NeoR.

Targeting of the tumor necrosis factor receptor superfamily for cancer immunotherapy

NARCIS (Netherlands)

Bremer, Edwin

2013-01-01

The tumor necrosis factor (TNF) ligand and cognate TNF receptor superfamilies constitute an important regulatory axis that is pivotal for immune homeostasis and correct execution of immune responses. TNF ligands and receptors are involved in diverse biological processes ranging from the selective

Membrane interaction of retroviral Gag proteins

Directory of Open Access Journals (Sweden)

Robert Alfred Dick

2014-04-01

Full Text Available Assembly of an infectious retroviral particle relies on multimerization of the Gag polyprotein at the inner leaflet of the plasma membrane. The three domains of Gag common to all retroviruses-- MA, CA, and NC-- provide the signals for membrane binding, assembly, and viral RNA packaging, respectively. These signals do not function independently of one another. For example, Gag multimerization enhances membrane binding and is more efficient when NC is interacting with RNA. MA binding to the plasma membrane is governed by several principles, including electrostatics, recognition of specific lipid head groups, hydrophobic interactions, and membrane order. HIV-1 uses many of these principles while Rous sarcoma virus (RSV appears to use fewer. This review describes the principles that govern Gag interactions with membranes, focusing on RSV and HIV-1 Gag. The review also defines lipid and membrane behavior, and discusses the complexities in determining how lipid and membrane behavior impact Gag membrane binding.

Identification of endogenous retroviral reading frames in the human genome

Directory of Open Access Journals (Sweden)

Wiuf Carsten

2004-10-01

Full Text Available Abstract Background Human endogenous retroviruses (HERVs comprise a large class of repetitive retroelements. Most HERVs are ancient and invaded our genome at least 25 million years ago, except for the evolutionary young HERV-K group. The far majority of the encoded genes are degenerate due to mutational decay and only a few non-HERV-K loci are known to retain intact reading frames. Additional intact HERV genes may exist, since retroviral reading frames have not been systematically annotated on a genome-wide scale. Results By clustering of hits from multiple BLAST searches using known retroviral sequences we have mapped 1.1% of the human genome as retrovirus related. The coding potential of all identified HERV regions were analyzed by annotating viral open reading frames (vORFs and we report 7836 loci as verified by protein homology criteria. Among 59 intact or almost-intact viral polyproteins scattered around the human genome we have found 29 envelope genes including two novel gammaretroviral types. One encodes a protein similar to a recently discovered zebrafish retrovirus (ZFERV while another shows partial, C-terminal, homology to Syncytin (HERV-W/FRD. Conclusions This compilation of HERV sequences and their coding potential provide a useful tool for pursuing functional analysis such as RNA expression profiling and effects of viral proteins, which may, in turn, reveal a role for HERVs in human health and disease. All data are publicly available through a database at http://www.retrosearch.dk.

Evidence for the horizontal transfer of an integrase gene from a fusellovirus to a pRN-like plasmid within a single strain of Sulfolobus and the implications for plasmid survival

DEFF Research Database (Denmark)

Peng, Xu

2008-01-01

of the integrase gene occurs in the viral attachment site (attP), which corresponds to the anticodon region of the targeted tRNA gene in the host chromosome. This point mutation confers on pXZ1 the ability to integrate into the tRNA(Glu)[CUC] gene, which differs from the integration site of SSV4, t......RNA(Glu)[UUC]. SSV4 and pXZ1 were also shown experimentally to integrate into separate sites on the host chromosome. This is believed to be the first report of a pRN plasmid sharing its natural host with a fusellovirus and carrying a highly similar integrase gene....

Sex-specific aspects of endogenous retroviral insertion and deletion.

Science.gov (United States)

Gemmell, Patrick; Hein, Jotun; Katzourakis, Aris

2013-11-07

We wish to understand how sex and recombination affect endogenous retroviral insertion and deletion. While theory suggests that the risk of ectopic recombination will limit the accumulation of repetitive DNA in areas of high meiotic recombination, the experimental evidence so far has been inconsistent. Under the assumption of neutrality, we examine the genomes of eighteen species of animal in order to compute the ratio of solo-LTRs that derive from insertions occurring down the male germ line as opposed to the female one (male bias). We also extend the simple idea of comparing autosome to allosome in order to predict the ratio of full-length proviruses we would expect to see under conditions of recombination linked deletion or otherwise. Using our model, we predict the ratio of allosomal to autosomal full-length proviruses to lie between32 and 23 under increasing male bias in mammals and between 1 and 2 under increasing male bias in birds. In contrast to our expectations, we find that a pattern of male bias is not universal across species and that there is a frequent overabundance of full-length proviruses on the allosome beyond the ratios predicted by our model. We use our data as a whole to argue that full-length proviruses should be treated as deleterious mutations or as effectively neutral mutations whose persistence in a full-length state is linked to the rate of meiotic recombination and whose origin is not universally male biased. These conclusions suggest that retroviral insertions on the allosome may be more prolific and that it might be possible to identify mechanisms of replication that are enhanced in the female sex.

Evolution of Enzymatic Activities in the Enolase Superfamily: D-Mannonate Dhydratase from Novosphingobium aromaticivorans

Energy Technology Data Exchange (ETDEWEB)

Rakus,J.; Fedorov, A.; Fedorov, E.; Glasner, M.; Vick, J.; Babbitt, P.; Almo, S.; Gerlt, J.

2007-01-01

The d-mannonate dehydratase (ManD) function was assigned to a group of orthologous proteins in the mechanistically diverse enolase superfamily by screening a library of acid sugars. Structures of the wild type ManD from Novosphingobium aromaticivorans were determined at pH 7.5 in the presence of Mg2+ and also in the presence of Mg2+ and the 2-keto-3-keto-d-gluconate dehydration product; the structure of the catalytically active K271E mutant was determined at pH 5.5 in the presence of the d-mannonate substrate. As previously observed in the structures of other members of the enolase superfamily, ManD contains two domains, an N-terminal a+{beta} capping domain and a ({beta}/a)7{beta}-barrel domain. The barrel domain contains the ligands for the essential Mg2+, Asp 210, Glu 236, and Glu 262, at the ends of the third, fourth, and fifth {beta}-strands of the barrel domain, respectively. However, the barrel domain lacks both the Lys acid/base catalyst at the end of the second {beta}-strand and the His-Asp dyad acid/base catalyst at the ends of the seventh and sixth {beta}-strands, respectively, that are found in many members of the superfamily. Instead, a hydrogen-bonded dyad of Tyr 159 in a loop following the second {beta}-strand and Arg 147 at the end of the second {beta}-strand are positioned to initiate the reaction by abstraction of the 2-proton. Both Tyr 159 and His 212, at the end of the third {beta}-strand, are positioned to facilitate both syn-dehydration and ketonization of the resulting enol intermediate to yield the 2-keto-3-keto-d-gluconate product with the observed retention of configuration. The identities and locations of these acid/base catalysts as well as of cationic amino acid residues that stabilize the enolate anion intermediate define a new structural strategy for catalysis (subgroup) in the mechanistically diverse enolase superfamily. With these differences, we provide additional evidence that the ligands for the essential Mg2+ are the only

The role of S-S bridge in retroviral protease function and virion maturation

Czech Academy of Sciences Publication Activity Database

Zábranská, Helena; Tůma, R.; Kluh, Ivan; Svatoš, A.; Ruml, Tomáš; Hrabal, R.; Pichová, Iva

2007-01-01

Roč. 365, č. 5 (2007), s. 1493-1504 ISSN 0022-2836 R&D Projects: GA MŠk 1M0508; GA MŠk 1M0520; GA ČR GESCO/06/E001 Institutional research plan: CEZ:AV0Z40550506 Keywords : retroviral protease * Mason-Pfizer monkey virus * disulfide * dimerization Subject RIV: CE - Biochemistry Impact factor: 4.472, year: 2007

Murine leukemia virus-derived retroviral vector has differential integration patterns in human cell lines used to produce recombinant factor VIII

Directory of Open Access Journals (Sweden)

Marcela Cristina Correa de Freitas

2014-06-01

Full Text Available OBJECTIVE: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO and baby hamster kidney cells (BHK. Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.METHODS: This study used ligation-mediated polymerase chain reaction to locate the site of viral vector integration by sequencing polymerase chain reaction products. The sequences were compared to genomic databases to characterize respective clones.RESULTS: The retroviral vector presented different and non-random profiles of integration between cells lines. A preference of integration for chromosomes 19, 17 and 11 was observed for HepG2FVIIIdB/P140K and chromosome 9 for Hek293FVIIIdB/P140K. In genomic regions such as CpG islands and transcription factor binding sites, there was no difference in the integration profiles for both cell lines. Integration in intronic regions of encoding protein genes (RefSeq genes was also observed in both cell lines. Twenty percent of integrations occurred at fragile sites in the genome of the HepG2 cell line and 17% in Hek293.CONCLUSION: The results suggest that the cell type can affect the profile of chromosomal integration of the retroviral vector used; these differences may interfere in the level of expression of recombinant proteins.

Novel 3′-Processing Integrase Activity Assay by Real-Time PCR for Screening and Identification of HIV-1 Integrase Inhibitors

Directory of Open Access Journals (Sweden)

Supachai Sakkhachornphop

2015-01-01

Full Text Available The 3′-end processing (3′P of each viral long terminal repeat (LTR during human immunodeficiency virus type-1 (HIV-1 integration is a vital step in the HIV life cycle. Blocking the 3′P using 3′P inhibitor has recently become an attractive strategy for HIV-1 therapeutic intervention. Recently, we have developed a novel real-time PCR based assay for the detection of 3′P activity in vitro. The methodology usually involves biotinylated HIV-1 LTR, HIV-1 integrase (IN, and specific primers and probe. In this novel assay, we designed the HIV-1 LTR substrate based on a sequence with a homology to HIV-1 LTR labeled at its 3′ end with biotin on the sense strand. Two nucleotides at the 3′ end were subsequently removed by IN activity. Only two nucleotides labeled biotin were captured on an avidin-coated tube; therefore, inhibiting the binding of primers and probe results in late signals in the real-time PCR. This novel assay has successfully detected both the 3′P activity of HIV-1 IN and the anti-IN activity by Raltegravir and sodium azide agent. This real-time PCR assay has been shown to be effective and inexpensive for a high-throughput screening of novel IN inhibitors.

Retroviral DNA integration: ASLV, HIV, and MLV show distinct target site preferences.

Directory of Open Access Journals (Sweden)

Rick S Mitchell

2004-08-01

Full Text Available The completion of the human genome sequence has made possible genome-wide studies of retroviral DNA integration. Here we report an analysis of 3,127 integration site sequences from human cells. We compared retroviral vectors derived from human immunodeficiency virus (HIV, avian sarcoma-leukosis virus (ASLV, and murine leukemia virus (MLV. Effects of gene activity on integration targeting were assessed by transcriptional profiling of infected cells. Integration by HIV vectors, analyzed in two primary cell types and several cell lines, strongly favored active genes. An analysis of the effects of tissue-specific transcription showed that it resulted in tissue-specific integration targeting by HIV, though the effect was quantitatively modest. Chromosomal regions rich in expressed genes were favored for HIV integration, but these regions were found to be interleaved with unfavorable regions at CpG islands. MLV vectors showed a strong bias in favor of integration near transcription start sites, as reported previously. ASLV vectors showed only a weak preference for active genes and no preference for transcription start regions. Thus, each of the three retroviruses studied showed unique integration site preferences, suggesting that virus-specific binding of integration complexes to chromatin features likely guides site selection.

The UDP glucuronosyltransferase gene superfamily: suggested nomenclature based on evolutionary divergence

NARCIS (Netherlands)

Burchell, B.; Nebert, D. W.; Nelson, D. R.; Bock, K. W.; Iyanagi, T.; Jansen, P. L.; Lancet, D.; Mulder, G. J.; Chowdhury, J. R.; Siest, G.

1991-01-01

A nomenclature system for the UDP glucuronosyltransferase superfamily is proposed, based on divergent evolution of the genes. A total of 26 distinct cDNAs in five mammalian species have been sequenced to date. Comparison of the deduced amino acid sequences leads to the definition of two families and

A global view of structure-function relationships in the tautomerase superfamily.

Science.gov (United States)

Davidson, Rebecca; Baas, Bert-Jan; Akiva, Eyal; Holliday, Gemma L; Polacco, Benjamin J; LeVieux, Jake A; Pullara, Collin R; Zhang, Yan Jessie; Whitman, Christian P; Babbitt, Patricia C

2018-02-16

The tautomerase superfamily (TSF) consists of more than 11,000 nonredundant sequences present throughout the biosphere. Characterized members have attracted much attention because of the unusual and key catalytic role of an N-terminal proline. These few characterized members catalyze a diverse range of chemical reactions, but the full scale of their chemical capabilities and biological functions remains unknown. To gain new insight into TSF structure-function relationships, we performed a global analysis of similarities across the entire superfamily and computed a sequence similarity network to guide classification into distinct subgroups. Our results indicate that TSF members are found in all domains of life, with most being present in bacteria. The eukaryotic members of the cis -3-chloroacrylic acid dehalogenase subgroup are limited to fungal species, whereas the macrophage migration inhibitory factor subgroup has wide eukaryotic representation (including mammals). Unexpectedly, we found that 346 TSF sequences lack Pro-1, of which 85% are present in the malonate semialdehyde decarboxylase subgroup. The computed network also enabled the identification of similarity paths, namely sequences that link functionally diverse subgroups and exhibit transitional structural features that may help explain reaction divergence. A structure-guided comparison of these linker proteins identified conserved transitions between them, and kinetic analysis paralleled these observations. Phylogenetic reconstruction of the linker set was consistent with these findings. Our results also suggest that contemporary TSF members may have evolved from a short 4-oxalocrotonate tautomerase-like ancestor followed by gene duplication and fusion. Our new linker-guided strategy can be used to enrich the discovery of sequence/structure/function transitions in other enzyme superfamilies. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Spatial and temporal expression of immunoglobulin superfamily member 1 in the rat

NARCIS (Netherlands)

Joustra, Sjoerd D.; Meijer, Onno C.; Heinen, Charlotte A.; Mol, Isabel M.; Laghmani, El Houari; Sengers, Rozemarijn M. A.; Carreno, Gabriela; van Trotsenburg, A. S. Paul; Biermasz, Nienke R.; Bernard, Daniel J.; Wit, Jan M.; Oostdijk, Wilma; van Pelt, Ans M. M.; Hamer, Geert; Wagenaar, Gerry T. M.

2015-01-01

Loss-of-function mutations in the immunoglobulin superfamily member 1 (IGSF1) gene cause an X-linked syndrome of central hypothyroidism, macroorchidism, variable prolactin and GH deficiency, delayed pubertal testosterone rise, and obesity. To understand the pathophysiology of this syndrome,

Modulation of the functional association between the HIV-1 intasome and the nucleosome by histone amino-terminal tails.

Science.gov (United States)

Benleulmi, Mohamed S; Matysiak, Julien; Robert, Xavier; Miskey, Csaba; Mauro, Eric; Lapaillerie, Delphine; Lesbats, Paul; Chaignepain, Stéphane; Henriquez, Daniel R; Calmels, Christina; Oladosu, Oyindamola; Thierry, Eloïse; Leon, Oscar; Lavigne, Marc; Andreola, Marie-Line; Delelis, Olivier; Ivics, Zoltán; Ruff, Marc; Gouet, Patrice; Parissi, Vincent

2017-11-28

Stable insertion of the retroviral DNA genome into host chromatin requires the functional association between the intasome (integrase·viral DNA complex) and the nucleosome. The data from the literature suggest that direct protein-protein contacts between integrase and histones may be involved in anchoring the intasome to the nucleosome. Since histone tails are candidates for interactions with the incoming intasomes we have investigated whether they could participate in modulating the nucleosomal integration process. We show here that histone tails are required for an optimal association between HIV-1 integrase (IN) and the nucleosome for efficient integration. We also demonstrate direct interactions between IN and the amino-terminal tail of human histone H4 in vitro. Structure/function studies enabled us to identify amino acids in the carboxy-terminal domain of IN that are important for this interaction. Analysis of the nucleosome-binding properties of catalytically active mutated INs confirmed that their ability to engage the nucleosome for integration in vitro was affected. Pseudovirus particles bearing mutations that affect the IN/H4 association also showed impaired replication capacity due to altered integration and re-targeting of their insertion sites toward dynamic regions of the chromatin with lower nucleosome occupancy. Collectively, our data support a functional association between HIV-1 IN and histone tails that promotes anchoring of the intasome to nucleosomes and optimal integration into chromatin.

Immune responses to transgene and retroviral vector in patients treated with ex vivo-engineered T cells

NARCIS (Netherlands)

Lamers, C.H.; Willemsen, R.; Elzakker, P. van; Steenbergen-Langeveld, S. van; Broertjes, M.; Oosterwijk-Wakka, J.C.; Oosterwijk, E.; Sleijfer, S.; Debets, R.; Gratama, J.W.

2011-01-01

Adoptive transfer of immune effector cells that are gene modified by retroviral transduction to express tumor-specific receptors constitutes an attractive approach to treat cancer. In patients with metastatic renal cell carcinoma, we performed a study with autologous T cells genetically retargeted

Alteration of blood-brain barrier integrity by retroviral infection.

Directory of Open Access Journals (Sweden)

Philippe V Afonso

2008-11-01

Full Text Available The blood-brain barrier (BBB, which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans, both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies.

Evolution and Diversity of the Ras Superfamily of Small GTPases in Prokaryotes

Science.gov (United States)

Wuichet, Kristin; Søgaard-Andersen, Lotte

2015-01-01

The Ras superfamily of small GTPases are single domain nucleotide-dependent molecular switches that act as highly tuned regulators of complex signal transduction pathways. Originally identified in eukaryotes for their roles in fundamental cellular processes including proliferation, motility, polarity, nuclear transport, and vesicle transport, recent studies have revealed that single domain GTPases also control complex functions such as cell polarity, motility, predation, development and antibiotic resistance in bacteria. Here, we used a computational genomics approach to understand the abundance, diversity, and evolution of small GTPases in prokaryotes. We collected 520 small GTPase sequences present in 17% of 1,611 prokaryotic genomes analyzed that cover diverse lineages. We identified two discrete families of small GTPases in prokaryotes that show evidence of three distinct catalytic mechanisms. The MglA family includes MglA homologs, which are typically associated with the MglB GTPase activating protein, whereas members of the Rup (Ras superfamily GTPase of unknown function in prokaryotes) family are not predicted to interact with MglB homologs. System classification and genome context analyses support the involvement of small GTPases in diverse prokaryotic signal transduction pathways including two component systems, laying the foundation for future experimental characterization of these proteins. Phylogenetic analysis of prokaryotic and eukaryotic GTPases supports that the last universal common ancestor contained ancestral MglA and Rup family members. We propose that the MglA family was lost from the ancestral eukaryote and that the Ras superfamily members in extant eukaryotes are the result of vertical and horizontal gene transfer events of ancestral Rup GTPases. PMID:25480683

Using sequence similarity networks for visualization of relationships across diverse protein superfamilies.

Directory of Open Access Journals (Sweden)

Holly J Atkinson

Full Text Available The dramatic increase in heterogeneous types of biological data--in particular, the abundance of new protein sequences--requires fast and user-friendly methods for organizing this information in a way that enables functional inference. The most widely used strategy to link sequence or structure to function, homology-based function prediction, relies on the fundamental assumption that sequence or structural similarity implies functional similarity. New tools that extend this approach are still urgently needed to associate sequence data with biological information in ways that accommodate the real complexity of the problem, while being accessible to experimental as well as computational biologists. To address this, we have examined the application of sequence similarity networks for visualizing functional trends across protein superfamilies from the context of sequence similarity. Using three large groups of homologous proteins of varying types of structural and functional diversity--GPCRs and kinases from humans, and the crotonase superfamily of enzymes--we show that overlaying networks with orthogonal information is a powerful approach for observing functional themes and revealing outliers. In comparison to other primary methods, networks provide both a good representation of group-wise sequence similarity relationships and a strong visual and quantitative correlation with phylogenetic trees, while enabling analysis and visualization of much larger sets of sequences than trees or multiple sequence alignments can easily accommodate. We also define important limitations and caveats in the application of these networks. As a broadly accessible and effective tool for the exploration of protein superfamilies, sequence similarity networks show great potential for generating testable hypotheses about protein structure-function relationships.

Using sequence similarity networks for visualization of relationships across diverse protein superfamilies.

Science.gov (United States)

Atkinson, Holly J; Morris, John H; Ferrin, Thomas E; Babbitt, Patricia C

2009-01-01

The dramatic increase in heterogeneous types of biological data--in particular, the abundance of new protein sequences--requires fast and user-friendly methods for organizing this information in a way that enables functional inference. The most widely used strategy to link sequence or structure to function, homology-based function prediction, relies on the fundamental assumption that sequence or structural similarity implies functional similarity. New tools that extend this approach are still urgently needed to associate sequence data with biological information in ways that accommodate the real complexity of the problem, while being accessible to experimental as well as computational biologists. To address this, we have examined the application of sequence similarity networks for visualizing functional trends across protein superfamilies from the context of sequence similarity. Using three large groups of homologous proteins of varying types of structural and functional diversity--GPCRs and kinases from humans, and the crotonase superfamily of enzymes--we show that overlaying networks with orthogonal information is a powerful approach for observing functional themes and revealing outliers. In comparison to other primary methods, networks provide both a good representation of group-wise sequence similarity relationships and a strong visual and quantitative correlation with phylogenetic trees, while enabling analysis and visualization of much larger sets of sequences than trees or multiple sequence alignments can easily accommodate. We also define important limitations and caveats in the application of these networks. As a broadly accessible and effective tool for the exploration of protein superfamilies, sequence similarity networks show great potential for generating testable hypotheses about protein structure-function relationships.

Bidirectional Retroviral Integration Site PCR Methodology and Quantitative Data Analysis Workflow.

Science.gov (United States)

Suryawanshi, Gajendra W; Xu, Song; Xie, Yiming; Chou, Tom; Kim, Namshin; Chen, Irvin S Y; Kim, Sanggu

2017-06-14

Integration Site (IS) assays are a critical component of the study of retroviral integration sites and their biological significance. In recent retroviral gene therapy studies, IS assays, in combination with next-generation sequencing, have been used as a cell-tracking tool to characterize clonal stem cell populations sharing the same IS. For the accurate comparison of repopulating stem cell clones within and across different samples, the detection sensitivity, data reproducibility, and high-throughput capacity of the assay are among the most important assay qualities. This work provides a detailed protocol and data analysis workflow for bidirectional IS analysis. The bidirectional assay can simultaneously sequence both upstream and downstream vector-host junctions. Compared to conventional unidirectional IS sequencing approaches, the bidirectional approach significantly improves IS detection rates and the characterization of integration events at both ends of the target DNA. The data analysis pipeline described here accurately identifies and enumerates identical IS sequences through multiple steps of comparison that map IS sequences onto the reference genome and determine sequencing errors. Using an optimized assay procedure, we have recently published the detailed repopulation patterns of thousands of Hematopoietic Stem Cell (HSC) clones following transplant in rhesus macaques, demonstrating for the first time the precise time point of HSC repopulation and the functional heterogeneity of HSCs in the primate system. The following protocol describes the step-by-step experimental procedure and data analysis workflow that accurately identifies and quantifies identical IS sequences.

Origination, expansion, evolutionary trajectory, and expression bias of AP2/ERF superfamily in Brassica napus

Directory of Open Access Journals (Sweden)

Xiaoming Song

2016-08-01

Full Text Available The AP2/ERF superfamily, one of the most important transcription factor families, plays crucial roles in response to biotic and abiotic stresses. So far, a comprehensive evolutionary inference of its origination and expansion has not been available. Here, we identified 515 AP2/ERF genes in B. napus, a neo-tetraploid forming ~7500 years ago, and found that 82.14% of them were duplicated in the tetraploidization. A prominent subgenome bias was revealed in gene expression, tissue-specific, and gene conversion. Moreover, a large-scale analysis across plants and alga suggested that this superfamily could have been originated from AP2 family, expanding to form other families (ERF, and RAV. This process was accompanied by duplicating and/or alternative deleting AP2 domain, intragenic domain sequence conversion, and/or by acquiring other domains, resulting in copy number variations, alternatively contributing to functional innovation. We found that significant positive selection occurred at certain critical nodes during the evolution of land plants, possibly responding to changing environment. In conclusion, the present research revealed origination, functional innovation, and evolutionary trajectory of the AP2/ERF superfamily, contributing to understanding their roles in plant stress tolerance.

In-silico gene co-expression network analysis in Paracoccidioides brasiliensis with reference to haloacid dehalogenase superfamily hydrolase gene

Directory of Open Access Journals (Sweden)

Raghunath Satpathy

2015-01-01

Full Text Available Context: Paracoccidioides brasiliensis, a dimorphic fungus is the causative agent of paracoccidioidomycosis, a disease globally affecting millions of people. The haloacid dehalogenase (HAD superfamily hydrolases enzyme in the fungi, in particular, is known to be responsible in the pathogenesis by adhering to the tissue. Hence, identification of novel drug targets is essential. Aims: In-silico based identification of co-expressed genes along with HAD superfamily hydrolase in P. brasiliensis during the morphogenesis from mycelium to yeast to identify possible genes as drug targets. Materials and Methods: In total, four datasets were retrieved from the NCBI-gene expression omnibus (GEO database, each containing 4340 genes, followed by gene filtration expression of the data set. Further co-expression (CE study was performed individually and then a combination these genes were visualized in the Cytoscape 2. 8.3. Statistical Analysis Used: Mean and standard deviation value of the HAD superfamily hydrolase gene was obtained from the expression data and this value was subsequently used for the CE calculation purpose by selecting specific correlation power and filtering threshold. Results: The 23 genes that were thus obtained are common with respect to the HAD superfamily hydrolase gene. A significant network was selected from the Cytoscape network visualization that contains total 7 genes out of which 5 genes, which do not have significant protein hits, obtained from gene annotation of the expressed sequence tags by BLAST X. For all the protein PSI-BLAST was performed against human genome to find the homology. Conclusions: The gene co-expression network was obtained with respect to HAD superfamily dehalogenase gene in P. Brasiliensis.

Comparative analysis of cation/proton antiporter superfamily in plants.

Science.gov (United States)

Ye, Chu-Yu; Yang, Xiaohan; Xia, Xinli; Yin, Weilun

2013-06-01

The cation/proton antiporter superfamily is associated with the transport of monovalent cations across membranes. This superfamily was annotated in the Arabidopsis genome and some members were functionally characterized. In the present study, a systematic analysis of the cation/proton antiporter genes in diverse plant species was reported. We identified 240 cation/proton antiporters in alga, moss, and angiosperm. A phylogenetic tree was constructed showing these 240 members are separated into three families, i.e., Na(+)/H(+) exchangers, K(+) efflux antiporters, and cation/H(+) exchangers. Our analysis revealed that tandem and/or segmental duplications contribute to the expansion of cation/H(+) exchangers in the examined angiosperm species. Sliding window analysis of the nonsynonymous/synonymous substitution ratios showed some differences in the evolutionary fate of cation/proton antiporter paralogs. Furthermore, we identified over-represented motifs among these 240 proteins and found most motifs are family specific, demonstrating diverse evolution of the cation/proton antiporters among three families. In addition, we investigated the co-expressed genes of the cation/proton antiporters in Arabidopsis thaliana. The results showed some biological processes are enriched in the co-expressed genes, suggesting the cation/proton antiporters may be involved in these biological processes. Taken together, this study furthers our knowledge on cation/proton antiporters in plants. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative analysis of cystatin superfamily in platyhelminths.

Directory of Open Access Journals (Sweden)

Aijiang Guo

Full Text Available The cystatin superfamily is comprised of cysteine proteinase inhibitors and encompasses at least 3 subfamilies: stefins, cystatins and kininogens. In this study, the platyhelminth cystatin superfamily was identified and grouped into stefin and cystatin subfamilies. The conserved domain of stefins (G, QxVxG was observed in all members of platyhelminth stefins. The three characteristics of cystatins, the cystatin-like domain (G, QxVxG, PW, a signal peptide, and one or two conserved disulfide bonds, were observed in platyhelminths, with the exception of cestodes, which lacked the conserved disulfide bond. However, it is noteworthy that cestode cystatins had two tandem repeated domains, although the second tandem repeated domain did not contain a cystatin-like domain, which has not been previously reported. Tertiary structure analysis of Taenia solium cystatin, one of the cestode cystatins, demonstrated that the N-terminus of T. solium cystatin formed a five turn α-helix, a five stranded β-pleated sheet and a hydrophobic edge, similar to the structure of chicken cystatin. Although no conserved disulfide bond was found in T. solium cystatin, the models of T. solium cystatin and chicken cystatin corresponded at the site of the first disulfide bridge of the chicken cystatin. However, the two models were not similar regarding the location of the second disulfide bridge of chicken cystatin. These results showed that T. solium cystatin and chicken cystatin had similarities and differences, suggesting that the biochemistry of T. solium cystatin could be similar to chicken cystatin in its inhibitory function and that it may have further functional roles. The same results were obtained for other cestode cystatins. Phylogenetic analysis showed that cestode cystatins constituted an independent clade and implied that cestode cystatins should be considered to have formed a new clade during evolution.

The ATPase of the phi29 DNA packaging motor is a member of the hexameric AAA+ superfamily.

Science.gov (United States)

Schwartz, Chad; De Donatis, Gian Marco; Fang, Huaming; Guo, Peixuan

2013-08-15

The AAA+ superfamily of proteins is a class of motor ATPases performing a wide range of functions that typically exist as hexamers. The ATPase of phi29 DNA packaging motor has long been a subject of debate in terms of stoichiometry and mechanism of action. Here, we confirmed the stoichiometry of phi29 motor ATPase to be a hexamer and provide data suggesting that the phi29 motor ATPase is a member of the classical hexameric AAA+ superfamily. Native PAGE, EMSA, capillary electrophoresis, ATP titration, and binomial distribution assay show that the ATPase is a hexamer. Mutations in the known Walker motifs of the ATPase validated our previous assumptions that the protein exists as another member of this AAA+ superfamily. Our data also supports the finding that the phi29 DNA packaging motor uses a revolution mechanism without rotation or coiling (Schwartz et al., this issue). Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Retroviral RNA Dimerization: From Structure to Functions

Directory of Open Access Journals (Sweden)

Noé Dubois

2018-03-01

Full Text Available The genome of the retroviruses is a dimer composed by two homologous copies of genomic RNA (gRNA molecules of positive polarity. The dimerization process allows two gRNA molecules to be non-covalently linked together through intermolecular base-pairing. This step is critical for the viral life cycle and is highly conserved among retroviruses with the exception of spumaretroviruses. Furthermore, packaging of two gRNA copies into viral particles presents an important evolutionary advantage for immune system evasion and drug resistance. Recent studies reported RNA switches models regulating not only gRNA dimerization, but also translation and packaging, and a spatio-temporal characterization of viral gRNA dimerization within cells are now at hand. This review summarizes our current understanding on the structural features of the dimerization signals for a variety of retroviruses (HIVs, MLV, RSV, BLV, MMTV, MPMV…, the mechanisms of RNA dimer formation and functional implications in the retroviral cycle.

Plasmid integration in a wide range of bacteria mediated by the integrase of Lactobacillus delbrueckii bacteriophage mv4.

Science.gov (United States)

Auvray, F; Coddeville, M; Ritzenthaler, P; Dupont, L

1997-01-01

Bacteriophage mv4 is a temperate phage infecting Lactobacillus delbrueckii subsp. bulgaricus. During lysogenization, the phage integrates its genome into the host chromosome at the 3' end of a tRNA(Ser) gene through a site-specific recombination process (L. Dupont et al., J. Bacteriol., 177:586-595, 1995). A nonreplicative vector (pMC1) based on the mv4 integrative elements (attP site and integrase-coding int gene) is able to integrate into the chromosome of a wide range of bacterial hosts, including Lactobacillus plantarum, Lactobacillus casei (two strains), Lactococcus lactis subsp. cremoris, Enterococcus faecalis, and Streptococcus pneumoniae. Integrative recombination of pMC1 into the chromosomes of all of these species is dependent on the int gene product and occurs specifically at the pMC1 attP site. The isolation and sequencing of pMC1 integration sites from these bacteria showed that in lactobacilli, pMC1 integrated into the conserved tRNA(Ser) gene. In the other bacterial species where this tRNA gene is less or not conserved; secondary integration sites either in potential protein-coding regions or in intergenic DNA were used. A consensus sequence was deduced from the analysis of the different integration sites. The comparison of these sequences demonstrated the flexibility of the integrase for the bacterial integration site and suggested the importance of the trinucleotide CCT at the 5' end of the core in the strand exchange reaction. PMID:9068626

Transgenic mice produced by retroviral transduction of male germ-line stem cells

OpenAIRE

Nagano, Makoto; Brinster, Clayton J.; Orwig, Kyle E.; Ryu, Buom-Yong; Avarbock, Mary R.; Brinster, Ralph L.

2001-01-01

Male germ-line stem cells are the only cell type in postnatal mammals that have the capability to self-renew and to contribute genes to the next generation. Genetic modification of these cells would provide an opportunity to study the biology of their complex self-renewal and differentiation processes, as well as enable the generation of transgenic animals in a wide range of species. Although retroviral vectors have been used as an efficient method to introduce genes into a variety of cell ty...

Retroviral expression screening of oncogenes in natural killer cell leukemia.

Science.gov (United States)

Choi, Young Lim; Moriuchi, Ryozo; Osawa, Mitsujiro; Iwama, Atsushi; Makishima, Hideki; Wada, Tomoaki; Kisanuki, Hiroyuki; Kaneda, Ruri; Ota, Jun; Koinuma, Koji; Ishikawa, Madoka; Takada, Shuji; Yamashita, Yoshihiro; Oshimi, Kazuo; Mano, Hiroyuki

2005-08-01

Aggressive natural killer cell leukemia (ANKL) is an intractable malignancy that is characterized by the outgrowth of NK cells. To identify transforming genes in ANKL, we constructed a retroviral cDNA expression library from an ANKL cell line KHYG-1. Infection of 3T3 cells with recombinant retroviruses yielded 33 transformed foci. Nucleotide sequencing of the DNA inserts recovered from these foci revealed that 31 of them encoded KRAS2 with a glycine-to-alanine mutation at codon 12. Mutation-specific PCR analysis indicated that the KRAS mutation was present only in KHYG-1 cells, not in another ANKL cell line or in clinical specimens (n=8).

Proteomics computational analyses suggest that baculovirus GP64 superfamily proteins are class III penetrenes

Directory of Open Access Journals (Sweden)

Garry Robert F

2008-02-01

Full Text Available Abstract Background Members of the Baculoviridae encode two types of proteins that mediate virus:cell membrane fusion and penetration into the host cell. Alignments of primary amino acid sequences indicate that baculovirus fusion proteins of group I nucleopolyhedroviruses (NPV form the GP64 superfamily. The structure of these viral penetrenes has not been determined. The GP64 superfamily includes the glycoprotein (GP encoded by members of the Thogotovirus genus of the Orthomyxoviridae. The entry proteins of other baculoviruses, group II NPV and granuloviruses, are class I penetrenes. Results Class III penetrenes encoded by members of the Rhabdoviridae and Herpesviridae have an internal fusion domain comprised of beta sheets, other beta sheet domains, an extended alpha helical domain, a membrane proximal stem domain and a carboxyl terminal anchor. Similar sequences and structural/functional motifs that characterize class III penetrenes are located collinearly in GP64 of group I baculoviruses and related glycoproteins encoded by thogotoviruses. Structural models based on a prototypic class III penetrene, vesicular stomatitis virus glycoprotein (VSV G, were established for Thogoto virus (THOV GP and Autographa california multiple NPV (AcMNPV GP64 demonstrating feasible cysteine linkages. Glycosylation sites in THOV GP and AcMNPV GP64 appear in similar model locations to the two glycosylation sites of VSV G. Conclusion These results suggest that proteins in the GP64 superfamily are class III penetrenes.

Mechanisms and factors that influence high frequency retroviral recombination

DEFF Research Database (Denmark)

Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga

2011-01-01

With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse...... transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity...... of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment...

Membrane and Protein Interactions of the Pleckstrin Homology Domain Superfamily

Directory of Open Access Journals (Sweden)

Marc Lenoir

2015-10-01

Full Text Available The human genome encodes about 285 proteins that contain at least one annotated pleckstrin homology (PH domain. As the first phosphoinositide binding module domain to be discovered, the PH domain recruits diverse protein architectures to cellular membranes. PH domains constitute one of the largest protein superfamilies, and have diverged to regulate many different signaling proteins and modules such as Dbl homology (DH and Tec homology (TH domains. The ligands of approximately 70 PH domains have been validated by binding assays and complexed structures, allowing meaningful extrapolation across the entire superfamily. Here the Membrane Optimal Docking Area (MODA program is used at a genome-wide level to identify all membrane docking PH structures and map their lipid-binding determinants. In addition to the linear sequence motifs which are employed for phosphoinositide recognition, the three dimensional structural features that allow peripheral membrane domains to approach and insert into the bilayer are pinpointed and can be predicted ab initio. The analysis shows that conserved structural surfaces distinguish which PH domains associate with membrane from those that do not. Moreover, the results indicate that lipid-binding PH domains can be classified into different functional subgroups based on the type of membrane insertion elements they project towards the bilayer.

Membrane and Protein Interactions of the Pleckstrin Homology Domain Superfamily.

Science.gov (United States)

Lenoir, Marc; Kufareva, Irina; Abagyan, Ruben; Overduin, Michael

2015-10-23

The human genome encodes about 285 proteins that contain at least one annotated pleckstrin homology (PH) domain. As the first phosphoinositide binding module domain to be discovered, the PH domain recruits diverse protein architectures to cellular membranes. PH domains constitute one of the largest protein superfamilies, and have diverged to regulate many different signaling proteins and modules such as Dbl homology (DH) and Tec homology (TH) domains. The ligands of approximately 70 PH domains have been validated by binding assays and complexed structures, allowing meaningful extrapolation across the entire superfamily. Here the Membrane Optimal Docking Area (MODA) program is used at a genome-wide level to identify all membrane docking PH structures and map their lipid-binding determinants. In addition to the linear sequence motifs which are employed for phosphoinositide recognition, the three dimensional structural features that allow peripheral membrane domains to approach and insert into the bilayer are pinpointed and can be predicted ab initio. The analysis shows that conserved structural surfaces distinguish which PH domains associate with membrane from those that do not. Moreover, the results indicate that lipid-binding PH domains can be classified into different functional subgroups based on the type of membrane insertion elements they project towards the bilayer.

The HIV-1 integrase-LEDGF allosteric inhibitor MUT-A: resistance profile, impairment of virus maturation and infectivity but without influence on RNA packaging or virus immunoreactivity

NARCIS (Netherlands)

Amadori, Céline; Ubeles van der Velden, Yme; Bonnard, Damien; Orlov, Igor; van Bel, Nikki; Le Rouzic, Erwann; Miralles, Laia; Brias, Julie; Chevreuil, Francis; Spehner, Daniele; Chasset, Sophie; Ledoussal, Benoit; Mayr, Luzia; Moreau, François; García, Felipe; Gatell, José; Zamborlini, Alessia; Emiliani, Stéphane; Ruff, Marc; Klaholz, Bruno P.; Moog, Christiane; Berkhout, Ben; Plana, Montserrat; Benarous, Richard

2017-01-01

HIV-1 Integrase (IN) interacts with the cellular co-factor LEDGF/p75 and tethers the HIV preintegration complex to the host genome enabling integration. Recently a new class of IN inhibitors was described, the IN-LEDGF allosteric inhibitors (INLAIs). Designed to interfere with the IN-LEDGF

Retroviral-mediated transfer and expression of human β-globin genes in cultured murine and human erythroid cells

International Nuclear Information System (INIS)

Weber-Benarous, A.; Cone, R.D.; London, I.M.; Mulligan, R.C.

1988-01-01

The authors cloned human β-globin DNA sequences from a genomic library prepared from DNA isolated from the human leukemia cell line K562 and have used the retroviral vector pZip-NeoSV(X)1 to introduce a 3.0-kilobase segment encompassing the globin gene into mouse erythroleukemia cells. Whereas the endogenous K562 β-globin gene is repressed in K562 cells, when introduced into mouse erythroleukemia cells by retroviral-mediated gene transfer, the β-globin gene from K562 cells was transcribed and induced 5-20-fold after treatment of the cells with dimethyl sulfoxide. The transcripts were correctly initiated, and expression and regulation of the K562 gene were identical to the expression of a normal human β-globin gene transferred into mouse erythroleukemia cells in the same way. They have also introduced the normal human β-globin gene into K562 cells using the same retrovirus vector. SP6 analysis of the RNA isolated from the transduced cells showed that the normal β-globin gene was transcribed at a moderately high level, before or after treatment with hemin. Based on these data, they suggest that the lack of expression of the endogenous β-globin gene in K562 cells does not result from an alteration in the gene itself and may not result from a lack of factor(s) necessary for β-lobin gene transcription. Retroviral-mediated transfer of the human β-globin gene may, however, uniquely influence expression of the gene K562 cells

Molecular purging of multiple myeloma cells by ex-vivo culture and retroviral transduction of mobilized-blood CD34+ cells

Directory of Open Access Journals (Sweden)

Corneo Gianmarco

2007-07-01

Full Text Available Abstract Background Tumor cell contamination of the apheresis in multiple myeloma is likely to affect disease-free and overall survival after autografting. Objective To purge myeloma aphereses from tumor contaminants with a novel culture-based purging method. Methods We cultured myeloma-positive CD34+ PB samples in conditions that retained multipotency of hematopoietic stem cells, but were unfavourable to survival of plasma cells. Moreover, we exploited the resistance of myeloma plasma cells to retroviral transduction by targeting the hematopoietic CD34+ cell population with a retroviral vector carrying a selectable marker (the truncated form of the human receptor for nerve growth factor, ΔNGFR. We performed therefore a further myeloma purging step by selecting the transduced cells at the end of the culture. Results Overall recovery of CD34+ cells after culture was 128.5%; ΔNGFR transduction rate was 28.8% for CD34+ cells and 0% for CD138-selected primary myeloma cells, respectively. Recovery of CD34+ cells after ΔNGFR selection was 22.3%. By patient-specific Ig-gene rearrangements, we assessed a decrease of 0.7–1.4 logs in tumor load after the CD34+ cell selection, and up to 2.3 logs after culture and ΔNGFR selection. Conclusion We conclude that ex-vivo culture and retroviral-mediated transduction of myeloma leukaphereses provide an efficient tumor cell purging.

CD147 Immunoglobulin Superfamily Receptor Function and Role in Pathology

OpenAIRE

Iacono, Kathryn T.; Brown, Amy L.; Greene, Mark I.; Saouaf, Sandra J.

2007-01-01

The immunoglobulin superfamily member CD147 plays an important role in fetal, neuronal, lymphocyte and extracellular matrix development. Here we review the current understanding of CD147 expression and protein interactions with regard to CD147 function and its role in pathologic conditions including heart disease, Alzheimer’s disease, stroke and cancer. A model linking hypoxic conditions found within the tumor microenvironment to up-regulation of CD147 expression and tumor progression is intr...

HIV-1 anti-retroviral drug effect on the C. albicans hyphal growth rate by a Bio-Cell Tracer system Efeito da droga anti-retroviral HIV-1 no crescimento de hifas de C. albicans monitoradas pelo sistema "Bio-Cell Tracer"

Directory of Open Access Journals (Sweden)

Nadja Rodrigues de Melo

2006-09-01

Full Text Available Declining incidence of oropharyngeal candidosis and opportunistic infections over recent years can be attributed to the use of highly active anti-retroviral therapy (HAART. Infection with C. albicans generally involves adherence and colonization of superficial tissues. During this process, budding yeasts are able to transform to hyphae and penetrate into the deep tissue. Using the biocell tracer system, C. albicans hyphal growth was dynamically observed at the cellular level. Ritonavir was effective in the inhibition of hyphal growth with growth rate of 0.8 mum/min. This study showed the in vitro effect of HIV anti-retroviral drug on the growth rate of the C. albicans hyphae.O declínio na incidência de candidose orofaríngea e infecções oportunistas associadas a infecção pelo HIV tem sido atribuído a introdução da terapia antiretroviral combinada (HAART. Infecção por C. albicans envolve aderência e colonização da mucosa superficial. Durante este processo leveduras são capazes de transformar-se na forma de hifas e penetrar nos tecidos mais profundos. Usando o sistema "Bio-Cell Tracer", o crescimento de hifas de C. albicans foi observado dinamicamente a nível celular. Ritonavir, inibidor de protease do HIV, foi efetivo na inibição do crescimento de hifas com media de 0.8 mim/min.O presente estudo demonstrou o efeito in vitro de um agente anti-retroviral HIV sobre o crescimento de hifas de C. albicans.

Spectrum of imaging appearances of intracranial cryptococcal infection in HIV/AIDS patients in the anti-retroviral therapy era

International Nuclear Information System (INIS)

Offiah, Curtis E.; Naseer, Aisha

2016-01-01

Cryptococcus neoformans infection is the most common fungal infection of the central nervous system (CNS) in advanced human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) patients, but remains a relatively uncommon CNS infection in both the immunocompromised and immunocompetent patient population, rendering it a somewhat elusive and frequently overlooked diagnosis. The morbidity and mortality associated with CNS cryptococcal infection can be significantly reduced by early recognition of the imaging appearances by the radiologist in order to focus and expedite clinical management and treatment. The emergence and evolution of anti-retroviral therapy have also impacted significantly on the imaging appearances, morbidity, and mortality of this neuro-infection. The constellation of varied imaging appearances associated with cryptococcal CNS infection in the HIV and AIDS population in the era of highly active anti-retroviral therapy (HAART) will be presented in this review.

Involvement of human endogenous retroviral syncytin-1 in human osteoclast fusion

DEFF Research Database (Denmark)

Søe, Kent; Andersen, Thomas Lykke; Hobolt-Pedersen, Anne-Sofie

2011-01-01

fusion of the lipid bilayers of their cell membranes are still unknown. Syncytin-1 is a protein encoded by a human endogenous retroviral gene which was stably integrated into the human ancestor genome more than 24 million years ago. Upon activation, syncytin-1 is able to destabilize the lipid bilayer....... This was documented through Q-PCR, Western blot and immunofluorescence analyses. These in vitro findings were confirmed by immunohistochemical stainings in human iliac crest biopsies. A syncytin-1 inhibitory peptide reduced the number of nuclei per osteoclast by 30%, as well as TRACP activity. From a mechanistic...

The Association between Gene-Environment Interactions and Diseases Involving the Human GST Superfamily with SNP Variants

Directory of Open Access Journals (Sweden)

Antoinesha L. Hollman

2016-03-01

Full Text Available Exposure to environmental hazards has been associated with diseases in humans. The identification of single nucleotide polymorphisms (SNPs in human populations exposed to different environmental hazards, is vital for detecting the genetic risks of some important human diseases. Several studies in this field have been conducted on glutathione S-transferases (GSTs, a phase II detoxification superfamily, to investigate its role in the occurrence of diseases. Human GSTs consist of cytosolic and microsomal superfamilies that are further divided into subfamilies. Based on scientific search engines and a review of the literature, we have found a large amount of published articles on human GST super- and subfamilies that have greatly assisted in our efforts to examine their role in health and disease. Because of its polymorphic variations in relation to environmental hazards such as air pollutants, cigarette smoke, pesticides, heavy metals, carcinogens, pharmaceutical drugs, and xenobiotics, GST is considered as a significant biomarker. This review examines the studies on gene-environment interactions related to various diseases with respect to single nucleotide polymorphisms (SNPs found in the GST superfamily. Overall, it can be concluded that interactions between GST genes and environmental factors play an important role in human diseases.

Comparative genomic study of ALDH gene superfamily in Gossypium: A focus on Gossypium hirsutum under salt stress.

Directory of Open Access Journals (Sweden)

Yating Dong

Full Text Available Aldehyde dehydrogenases (ALDHs are a superfamily of enzymes which play important role in the scavenging of active aldehydes molecules. In present work, a comprehensive whole-genomic study of ALDH gene superfamily was carried out for an allotetraploid cultivated cotton species, G. hirsutum, as well as in parallel relative to their diploid progenitors, G. arboreum and G. raimondii. Totally, 30 and 58 ALDH gene sequences belong to 10 families were identified from diploid and allotetraploid cotton species, respectively. The gene structures among the members from same families were highly conserved. Whole-genome duplication and segmental duplication might be the major driver for the expansion of ALDH gene superfamily in G. hirsutum. In addition, the expression patterns of GhALDH genes were diverse across tissues. Most GhALDH genes were induced or repressed by salt stress in upland cotton. Our observation shed lights on the molecular evolutionary properties of ALDH genes in diploid cottons and their alloallotetraploid derivatives. It may be useful to mine key genes for improvement of cotton response to salt stress.

Ensembler: Enabling High-Throughput Molecular Simulations at the Superfamily Scale.

Directory of Open Access Journals (Sweden)

Daniel L Parton

2016-06-01

Full Text Available The rapidly expanding body of available genomic and protein structural data provides a rich resource for understanding protein dynamics with biomolecular simulation. While computational infrastructure has grown rapidly, simulations on an omics scale are not yet widespread, primarily because software infrastructure to enable simulations at this scale has not kept pace. It should now be possible to study protein dynamics across entire (superfamilies, exploiting both available structural biology data and conformational similarities across homologous proteins. Here, we present a new tool for enabling high-throughput simulation in the genomics era. Ensembler takes any set of sequences-from a single sequence to an entire superfamily-and shepherds them through various stages of modeling and refinement to produce simulation-ready structures. This includes comparative modeling to all relevant PDB structures (which may span multiple conformational states of interest, reconstruction of missing loops, addition of missing atoms, culling of nearly identical structures, assignment of appropriate protonation states, solvation in explicit solvent, and refinement and filtering with molecular simulation to ensure stable simulation. The output of this pipeline is an ensemble of structures ready for subsequent molecular simulations using computer clusters, supercomputers, or distributed computing projects like Folding@home. Ensembler thus automates much of the time-consuming process of preparing protein models suitable for simulation, while allowing scalability up to entire superfamilies. A particular advantage of this approach can be found in the construction of kinetic models of conformational dynamics-such as Markov state models (MSMs-which benefit from a diverse array of initial configurations that span the accessible conformational states to aid sampling. We demonstrate the power of this approach by constructing models for all catalytic domains in the human

Integrase-Deficient Lentiviral Vector as an All-in-One Platform for Highly Efficient CRISPR/Cas9-Mediated Gene Editing

Directory of Open Access Journals (Sweden)

Pavel I. Ortinski

2017-06-01

Full Text Available The CRISPR/Cas9 systems have revolutionized the field of genome editing by providing unprecedented control over gene sequences and gene expression in many species, including humans. Lentiviral vectors (LVs are one of the primary delivery platforms for the CRISPR/Cas9 system due to their ability to accommodate large DNA payloads and sustain robust expression in a wide range of dividing and non-dividing cells. However, long-term expression of LV-delivered Cas9/guide RNA may lead to undesirable off-target effects characterized by non-specific RNA-DNA interactions and off-target DNA cleavages. Integrase-deficient lentiviral vectors (IDLVs present an attractive means for delivery of CRISPR/Cas9 components because: (1 they are capable of transducing a broad range of cells and tissues, (2 have superior packaging capacity compared to other vectors (e.g., adeno-associated viral vectors, and (3 they are expressed transiently and demonstrate very weak integration capability. In this manuscript, we aimed to establish IDLVs as a means for safe and efficient delivery of CRISPR/Cas9. To this end, we developed an all-in-one vector cassette with increased production efficacy and demonstrated that CRISPR/Cas9 delivered by the improved IDLV vectors can mediate rapid and robust gene editing in human embryonic kidney (HEK293T cells and post-mitotic brain neurons in vivo, via transient expression and with higher gene-targeting specificity than the corresponding integrase-competent vectors.

TGF-β superfamily signaling in testis formation and early male germline development.

Science.gov (United States)

Young, Julia C; Wakitani, Shoichi; Loveland, Kate L

2015-09-01

The TGF-β ligand superfamily contains at least 40 members, many of which are produced and act within the mammalian testis to facilitate formation of sperm. Their progressive expression at key stages and in specific cell types determines the fertility of adult males, influencing testis development and controlling germline differentiation. BMPs are essential for the interactive instructions between multiple cell types in the early embryo that drive initial specification of gamete precursors. In the nascent foetal testis, several ligands including Nodal, TGF-βs, Activins and BMPs, serve as key masculinizing switches by regulating male germline pluripotency, somatic and germline proliferation, and testicular vascularization and architecture. In postnatal life, local production of these factors determine adult testis size by regulating Sertoli cell multiplication and differentiation, in addition to specifying germline differentiation and multiplication. Because TGF-β superfamily signaling is integral to testis formation, it affects processes that underlie testicular pathologies, including testicular cancer, and its potential to contribute to subfertility is beginning to be understood. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanisms and Factors that Influence High Frequency Retroviral Recombination

Science.gov (United States)

Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga; Mens, Helene; Pathak, Vinay K.; Hu, Wei-Shau

2011-01-01

With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment, and vaccine development. PMID:21994801

Evolution of the retroviral restriction gene Fv1: inhibition of non-MLV retroviruses.

Directory of Open Access Journals (Sweden)

Melvyn W Yap

2014-03-01

Full Text Available Fv1 is the prototypic restriction factor that protects against infection by the murine leukemia virus (MLV. It was first identified in cells that were derived from laboratory mice and was found to be homologous to the gag gene of an endogenous retrovirus (ERV. To understand the evolution of the host restriction gene from its retroviral origins, Fv1s from wild mice were isolated and characterized. Most of these possess intact open reading frames but not all restricted N-, B-, NR-or NB-tropic MLVs, suggesting that other viruses could have played a role in the selection of the gene. The Fv1s from Mus spretus and Mus caroli were found to restrict equine infectious anemia virus (EIAV and feline foamy virus (FFV respectively, indicating that Fv1 could have a broader target range than previously thought, including activity against lentiviruses and spumaviruses. Analyses of the Fv1 sequences revealed a number of residues in the C-terminal region that had evolved under positive selection. Four of these selected residues were found to be involved in the novel restriction by mapping studies. These results strengthen the similarities between the two capsid binding restriction factors, Fv1 and TRIM5α, which support the hypothesis that Fv1 defended mice against waves of retroviral infection possibly including non-MLVs as well as MLVs.

Genome-Wide Analysis of Transposon and Retroviral Insertions Reveals Preferential Integrations in Regions of DNA Flexibility.

Science.gov (United States)

Vrljicak, Pavle; Tao, Shijie; Varshney, Gaurav K; Quach, Helen Ngoc Bao; Joshi, Adita; LaFave, Matthew C; Burgess, Shawn M; Sampath, Karuna

2016-04-07

DNA transposons and retroviruses are important transgenic tools for genome engineering. An important consideration affecting the choice of transgenic vector is their insertion site preferences. Previous large-scale analyses of Ds transposon integration sites in plants were done on the basis of reporter gene expression or germ-line transmission, making it difficult to discern vertebrate integration preferences. Here, we compare over 1300 Ds transposon integration sites in zebrafish with Tol2 transposon and retroviral integration sites. Genome-wide analysis shows that Ds integration sites in the presence or absence of marker selection are remarkably similar and distributed throughout the genome. No strict motif was found, but a preference for structural features in the target DNA associated with DNA flexibility (Twist, Tilt, Rise, Roll, Shift, and Slide) was observed. Remarkably, this feature is also found in transposon and retroviral integrations in maize and mouse cells. Our findings show that structural features influence the integration of heterologous DNA in genomes, and have implications for targeted genome engineering. Copyright © 2016 Vrljicak et al.

Mutation of C/EBPalpha predisposes to the development of myeloid leukemia in a retroviral insertional mutagenesis screen

DEFF Research Database (Denmark)

Hasemann, Marie S; Damgaard, Inge; Schuster, Mikkel B

2008-01-01

and incomplete penetrance, suggesting that accumulation of secondary mutations is necessary for disease progression. Here, we use SRS19-6-driven retroviral insertional mutagenesis to compare the phenotypes of leukemias arising in Cebpa(+/+), Cebpa(+/BRM2), and Cebpa(BRM2/BRM2) mice, with respect to disease type...

Stability for Function Trade-Offs in the Enolase Superfamily 'Catalytic Module'

Energy Technology Data Exchange (ETDEWEB)

Nagatani, R.A.; Gonzalez, A.; Shoichet, B.K.; Brinen, L.S.; Babbitt, P.C.; /UC, San Francisco /SLAC, SSRL

2007-07-12

Enzyme catalysis reflects a dynamic interplay between charged and polar active site residues that facilitate function, stabilize transition states, and maintain overall protein stability. Previous studies show that substituting neutral for charged residues in the active site often significantly stabilizes a protein, suggesting a stability trade-off for functionality. In the enolase superfamily, a set of conserved active site residues (the ''catalytic module'') has repeatedly been used in nature in the evolution of many different enzymes for the performance of unique overall reactions involving a chemically diverse set of substrates. This catalytic module provides a robust solution for catalysis that delivers the common underlying partial reaction that supports all of the different overall chemical reactions of the superfamily. As this module has been so broadly conserved in the evolution of new functions, we sought to investigate the extent to which it follows the stability-function trade-off. Alanine substitutions were made for individual residues, groups of residues, and the entire catalytic module of o-succinylbenzoate synthase (OSBS), a member of the enolase superfamily from Escherichia coli. Of six individual residue substitutions, four (K131A, D161A, E190A, and D213A) substantially increased protein stability (by 0.46-4.23 kcal/mol), broadly consistent with prediction of a stability-activity trade-off. The residue most conserved across the superfamily, E190, is by far the most destabilizing. When the individual substitutions were combined into groups (as they are structurally and functionally organized), nonadditive stability effects emerged, supporting previous observations that residues within the module interact as two functional groups within a larger catalytic system. Thus, whereas the multiple-mutant enzymes D161A/E190A/D213A and K131A/K133A/D161A/E190A/D213A/K235A (termed 3KDED) are stabilized relative to the wild-type enzyme (by 1

SVM-Fold: a tool for discriminative multi-class protein fold and superfamily recognition.

Science.gov (United States)

Melvin, Iain; Ie, Eugene; Kuang, Rui; Weston, Jason; Stafford, William Noble; Leslie, Christina

2007-05-22

Predicting a protein's structural class from its amino acid sequence is a fundamental problem in computational biology. Much recent work has focused on developing new representations for protein sequences, called string kernels, for use with support vector machine (SVM) classifiers. However, while some of these approaches exhibit state-of-the-art performance at the binary protein classification problem, i.e. discriminating between a particular protein class and all other classes, few of these studies have addressed the real problem of multi-class superfamily or fold recognition. Moreover, there are only limited software tools and systems for SVM-based protein classification available to the bioinformatics community. We present a new multi-class SVM-based protein fold and superfamily recognition system and web server called SVM-Fold, which can be found at http://svm-fold.c2b2.columbia.edu. Our system uses an efficient implementation of a state-of-the-art string kernel for sequence profiles, called the profile kernel, where the underlying feature representation is a histogram of inexact matching k-mer frequencies. We also employ a novel machine learning approach to solve the difficult multi-class problem of classifying a sequence of amino acids into one of many known protein structural classes. Binary one-vs-the-rest SVM classifiers that are trained to recognize individual structural classes yield prediction scores that are not comparable, so that standard "one-vs-all" classification fails to perform well. Moreover, SVMs for classes at different levels of the protein structural hierarchy may make useful predictions, but one-vs-all does not try to combine these multiple predictions. To deal with these problems, our method learns relative weights between one-vs-the-rest classifiers and encodes information about the protein structural hierarchy for multi-class prediction. In large-scale benchmark results based on the SCOP database, our code weighting approach

A comprehensive analysis of the Omp85/TpsB protein superfamily structural diversity, taxonomic occurrence, and evolution

Science.gov (United States)

Heinz, Eva; Lithgow, Trevor

2014-01-01

Members of the Omp85/TpsB protein superfamily are ubiquitously distributed in Gram-negative bacteria, and function in protein translocation (e.g., FhaC) or the assembly of outer membrane proteins (e.g., BamA). Several recent findings are suggestive of a further level of variation in the superfamily, including the identification of the novel membrane protein assembly factor TamA and protein translocase PlpD. To investigate the diversity and the causal evolutionary events, we undertook a comprehensive comparative sequence analysis of the Omp85/TpsB proteins. A total of 10 protein subfamilies were apparent, distinguished in their domain structure and sequence signatures. In addition to the proteins FhaC, BamA, and TamA, for which structural and functional information is available, are families of proteins with so far undescribed domain architectures linked to the Omp85 β-barrel domain. This study brings a classification structure to a dynamic protein superfamily of high interest given its essential function for Gram-negative bacteria as well as its diverse domain architecture, and we discuss several scenarios of putative functions of these so far undescribed proteins. PMID:25101071

Raltegravir, elvitegravir, and metoogravir: the birth of "me-too" HIV-1 integrase inhibitors

Directory of Open Access Journals (Sweden)

Neamati Nouri

2009-03-01

Full Text Available Abstract Merck's MK-0518, known as raltegravir, has recently become the first FDA-approved HIV-1 integrase (IN inhibitor and has since risen to blockbuster drug status. Much research has in turn been conducted over the last few years aimed at recreating but optimizing the compound's interactions with the protein. Resulting me-too drugs have shown favorable pharmacokinetic properties and appear drug-like but, as expected, most have a highly similar interaction with IN to that of raltegravir. We propose that, based upon conclusions drawn from our docking studies illustrated herein, most of these me-too MK-0518 analogues may experience a low success rate against raltegravir-resistant HIV strains. As HIV has a very high mutational competence, the development of drugs with new mechanisms of inhibitory action and/or new active substituents may be a more successful route to take in the development of second- and third-generation IN inhibitors.

RetroTector online, a rational tool for analysis of retroviral elements in small and medium size vertebrate genomic sequences.

Science.gov (United States)

Sperber, Göran; Lövgren, Anders; Eriksson, Nils-Einar; Benachenhou, Farid; Blomberg, Jonas

2009-06-16

The rapid accumulation of genomic information in databases necessitates rapid and specific algorithms for extracting biologically meaningful information. More or less complete retroviral sequences, also called proviral or endogenous retroviral sequences; ERVs, constitutes at least 5% of vertebrate genomes. After infecting the host, these retroviruses have integrated in germ line cells, and have then been carried in genomes for at least several 100 million years. A better understanding of structure and function of these sequences can have profound biological and medical consequences. RetroTector (ReTe) is a platform-independent Java program for identification and characterization of proviral sequences in vertebrate genomes. The full ReTe requires a local installation with a MySQL database. Although not overly complicated, the installation may take some time. A "light" version of ReTe, (RetroTector online; ROL) which does not require specific installation procedures is provided, via the World Wide Web. ROL http://www.fysiologi.neuro.uu.se/jbgs/ was implemented under the Batchelor web interface (A Lövgren et al). It allows both GenBank accession number, file and FASTA cut-and-paste admission of sequences (5 to 10,000 kilobases). Up to ten submissions can be done simultaneously, allowing batch analysis of retroviral sequences found in the submitted sequence is graphically presented, exportable in standard formats. With the current server, a complete analysis of a 1 Megabase sequence is complete in 10 minutes. It is possible to mask nonretroviral repetitive sequences in the submitted sequence, using host genome specific "brooms", which increase specificity. Proviral sequences can be hard to recognize

ФC31 Integrase-Mediated Isolation and Characterization of Novel Safe Harbors for Transgene Expression in the Pig Genome

Science.gov (United States)

Bi, Yanzhen; Hua, Zaidong; Ren, Hongyan; Zhang, Liping; Xiao, Hongwei; Liu, Ximei; Hua, Wenjun; Mei, Shuqi; Molenaar, Adrian; Laible, Götz; Zheng, Xinmin

2018-01-01

Programmable nucleases have allowed the rapid development of gene editing and transgenics, but the technology still suffers from the lack of predefined genetic loci for reliable transgene expression and maintenance. To address this issue, we used ФC31 integrase to navigate the porcine genome and identify the pseudo attP sites suitable as safe harbors for sustained transgene expression. The combined ФC31 integrase mRNA and an enhanced green fluorescence protein (EGFP) reporter donor were microinjected into one-cell zygotes for transgene integration. Among the resulting seven EGFP-positive piglets, two had transgene integrations at pseudo attP sites, located in an intergenic region of chromosome 1 (chr1-attP) and the 6th intron of the TRABD2A gene on chromosome 3 (chr3-attP), respectively. The integration structure was determined by TAIL-PCR and Southern blotting. Primary fibroblast cells were isolated from the two piglets and examined using fluorescence-activated cell sorting (FACS) and enzyme-linked immunosorbent assay (ELISA), which demonstrated that the chr1-attP site was more potent than chr3-attP site in supporting the EGFP expression. Both piglets had green feet under the emission of UV light, and pelleted primary fibroblast cells were green-colored under natural light, corroborating that the two pseudo attP sites are beneficial to transgene expression. The discovery of these two novel safe harbors for robust and durable transgene expression will greatly facilitate the use of transgenic pigs for basic, biomedical and agricultural studies and applications. PMID:29300364

Retroviral-mediated gene transfer of human phenylalanine hydroxylase into NIH 3T3 and hepatoma cells

Energy Technology Data Exchange (ETDEWEB)

Ledley, F.D.; Grenett, H.E.; McGinnis-Shelnutt, M.; Woo, S.L.C.

1986-01-01

Phenylketonuria (PKU) is caused by deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH). A full-length human PAH cDNA sequence has been inserted into pzip-neoSV(X), which is a retroviral vector containing the bacterial neo gene. The recombinant has been transfected into Psi2 cells, which provide synthesis of the retroviral capsid. Recombinant virus was detected in the culture medium of the transfected Psi2 cells, which is capable of transmitting the human PAH gene into mouse NIH 3T3 cells by infection leading to stable incorporation of the recombinant provirus. Infected cells express PAH mRNA, immunoreactive PAH protein, and exhibit pterin-dependent phenylaline hydroxylase activity. The recombinant virus is also capable of infecting a mouse hepatoma cell line that does not normal synthesize PAH. PAH activity is present in the cellular extracts and the entire hydroxylation system is reconstituted in the hepatoma cells infected with the recombinant viruses. Thus, recombinant viruses containing human PAH cDNA provide a means for introducing functional PAH into mammalian cells of hepatic origin and can potentially be introduced into whole animals as a model for somatic gene therapy for PKU.

Evolution of Enzymatic Activities in the Enolase Superfamily: L-Rhamnonate Dehydratase

Energy Technology Data Exchange (ETDEWEB)

Rakus,J.; Fedorov, A.; Fedorov, E.; Glaner, M.; Hubbard, B.; Delli, J.; Babbitt, P.; Almo, S.; Gerlt, J.

2008-01-01

The l-rhamnonate dehydratase (RhamD) function was assigned to a previously uncharacterized family in the mechanistically diverse enolase superfamily that is encoded by the genome of Escherichia coli K-12. We screened a library of acid sugars to discover that the enzyme displays a promiscuous substrate specificity: l-rhamnonate (6-deoxy-l-mannonate) has the 'best' kinetic constants, with l-mannonate, l-lyxonate, and d-gulonate dehydrated less efficiently. Crystal structures of the RhamDs from both E. coli K-12 and Salmonella typhimurium LT2 (95% sequence identity) were obtained in the presence of Mg2+; the structure of the RhamD from S. typhimurium was also obtained in the presence of 3-deoxy-l-rhamnonate (obtained by reduction of the product with NaBH4). Like other members of the enolase superfamily, RhamD contains an N-terminal a + {beta} capping domain and a C-terminal ({beta}/a)7{beta}-barrel (modified TIM-barrel) catalytic domain with the active site located at the interface between the two domains. In contrast to other members, the specificity-determining '20s loop' in the capping domain is extended in length and the '50s loop' is truncated. The ligands for the Mg2+ are Asp 226, Glu 252 and Glu 280 located at the ends of the third, fourth and fifth {beta}-strands, respectively. The active site of RhamD contains a His 329-Asp 302 dyad at the ends of the seventh and sixth {beta}-strands, respectively, with His 329 positioned to function as the general base responsible for abstraction of the C2 proton of l-rhamnonate to form a Mg2+-stabilized enediolate intermediate. However, the active site does not contain other acid/base catalysts that have been implicated in the reactions catalyzed by other members of the MR subgroup of the enolase superfamily. Based on the structure of the liganded complex, His 329 also is expected to function as the general acid that both facilitates departure of the 3-OH group in a syn-dehydration reaction and

Electronic medication monitoring-informed counseling to improve adherence to combination anti-retroviral therapy and virologic treatment outcomes: a meta-analysis

NARCIS (Netherlands)

Langebeek, Nienke; Nieuwkerk, Pythia

2015-01-01

Adherence to combination anti-retroviral therapy for HIV infection is a primary determinant of treatment success, but is often suboptimal. Previous studies have suggested that electronic medication monitoring-informed counseling is among the most effective adherence intervention components. Our

Ultrasensitive liquid chromatography-tandem mass spectrometric methodologies for quantification of five HIV-1 integrase inhibitors in plasma for a microdose clinical trial.

Science.gov (United States)

Sun, Li; Li, Hankun; Willson, Kenneth; Breidinger, Sheila; Rizk, Matthew L; Wenning, Larissa; Woolf, Eric J

2012-10-16

HIV-1 integrase strand transfer inhibitors are an important class of compounds targeted for the treatment of HIV-1 infection. Microdosing has emerged as an attractive tool to assist in drug candidate screening for clinical development, but necessitates extremely sensitive bioanalytical assays, typically in the pg/mL concentration range. Currently, accelerator mass spectrometry is the predominant tool for microdosing support, which requires a specialized facility and synthesis of radiolabeled compounds. There have been few studies attempted to comprehensively assess a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach in the context of microdosing applications. Herein, we describe the development of automated LC-MS/MS methods to quantify five integrase inhibitors in plasma with the limits of quantification at 1 pg/mL for raltegravir and 2 pg/mL for four proprietary compounds. The assays involved double extractions followed by UPLC coupled with negative ion electrospray MS/MS analysis. All methods were fully validated to the rigor of regulated bioanalysis requirements, with intraday precision between 1.20 and 14.1% and accuracy between 93.8 and 107% at the standard curve concentration range. These methods were successfully applied to a human microdose study and demonstrated to be accurate, reproducible, and cost-effective. Results of the study indicate that raltegravir displayed linear pharmacokinetics between a microdose and a pharmacologically active dose.

Short interspersed elements (SINEs) of the Geomyoidea superfamily rodents.

Science.gov (United States)

Gogolevsky, Konstantin P; Kramerov, Dmitri A

2006-05-24

A new short interspersed element (SINE) was isolated from the genome of desert kangaroo rat (Dipodomys deserti) using single-primer PCR. This SINE consists of two monomers: the left monomer (IDL) resembles rodent ID element and other tRNAAla(CGC)-derived SINEs, whereas the right one (Geo) shows no similarity with known SINE sequences. PCR and hybridization analyses demonstrated that IDL-Geo SINE is restricted to the rodent superfamily Geomyoidea (families Geomyidea and Heteromyidea). Isolation and analysis of IDL-Geo from California pocket mouse (Chaetodipus californicus) and Botta's pocket gopher (Thomomys bottae) revealed some species-specific features of this SINE family. The structure and evolution of known dimeric SINEs are discussed.

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

Science.gov (United States)

Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

2015-01-01

Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

Directory of Open Access Journals (Sweden)

Feng-Xia Tian

Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Anti-HIV-1 integrase activity of medicinal plants used as self medication by AIDS patients

Directory of Open Access Journals (Sweden)

Sopa Kummee

2006-07-01

Full Text Available The extracts of selected medicinal plants used as self medication by AIDS patients were investigated for their inhibitory activities against HIV-1 integrase (HIV-1 IN using the multiplate integration assay (MIA. Of these, the water extract of Eclipta prostrata (whole plant exhibited the most potent inhibitory activity with an IC50 value of 4.8 μg/ml, followed by the methanol extract of Eclipta prostrata (whole plant, IC50 = 21.1 μg/ ml, the water extract of Barleria lupulina (stem, IC50 = 26.4 μg/ml, the chloroform extract of Barleria lupulina (stem, IC50 = 33.0 μg/ml, the methanol extract of Barleria lupulina (stem, IC50 = 38.2 μg/ml and the chloroform extract of Piper betle (leaf, IC50 = 39.3 μg/ml, respectively.

Historical perspectives on tumor necrosis factor and its superfamily: 25 years later, a golden journey.

Science.gov (United States)

Aggarwal, Bharat B; Gupta, Subash C; Kim, Ji Hye

2012-01-19

Although activity that induced tumor regression was observed and termed tumor necrosis factor (TNF) as early as the 1960s, the true identity of TNF was not clear until 1984, when Aggarwal and coworkers reported, for the first time, the isolation of 2 cytotoxic factors: one, derived from macrophages (molecular mass 17 kDa), was named TNF, and the second, derived from lymphocytes (20 kDa), was named lymphotoxin. Because the 2 cytotoxic factors exhibited 50% amino acid sequence homology and bound to the same receptor, they came to be called TNF-α and TNF-β. Identification of the protein sequences led to cloning of their cDNA. Based on sequence homology to TNF-α, now a total of 19 members of the TNF superfamily have been identified, along with 29 interacting receptors, and several molecules that interact with the cytoplasmic domain of these receptors. The roles of the TNF superfamily in inflammation, apoptosis, proliferation, invasion, angiogenesis, metastasis, and morphogenesis have been documented. Their roles in immunologic, cardiovascular, neurologic, pulmonary, and metabolic diseases are becoming apparent. TNF superfamily members are active targets for drug development, as indicated by the recent approval and expanding market of TNF blockers used to treat rheumatoid arthritis, psoriasis, Crohns disease, and osteoporosis, with a total market of more than US $20 billion. As we learn more about this family, more therapeutics will probably emerge. In this review, we summarize the initial discovery of TNF-α, and the insights gained regarding the roles of this molecule and its related family members in normal physiology and disease.

RetroTector online, a rational tool for analysis of retroviral elements in small and medium size vertebrate genomic sequences

Directory of Open Access Journals (Sweden)

Benachenhou Farid

2009-06-01

Full Text Available Abstract Background The rapid accumulation of genomic information in databases necessitates rapid and specific algorithms for extracting biologically meaningful information. More or less complete retroviral sequences, also called proviral or endogenous retroviral sequences; ERVs, constitutes at least 5% of vertebrate genomes. After infecting the host, these retroviruses have integrated in germ line cells, and have then been carried in genomes for at least several 100 million years. A better understanding of structure and function of these sequences can have profound biological and medical consequences. Methods RetroTector© (ReTe is a platform-independent Java program for identification and characterization of proviral sequences in vertebrate genomes. The full ReTe requires a local installation with a MySQL database. Although not overly complicated, the installation may take some time. A "light" version of ReTe, (RetroTector online; ROL which does not require specific installation procedures is provided, via the World Wide Web. Results ROL http://www.fysiologi.neuro.uu.se/jbgs/ was implemented under the Batchelor web interface (A Lövgren et al. It allows both GenBank accession number, file and FASTA cut-and-paste admission of sequences (5 to 10 000 kilobases. Up to ten submissions can be done simultaneously, allowing batch analysis of Discussion Proviral sequences can be hard to recognize, especially if the integration occurred many million years ago. Precise delineation of LTR, gag, pro, pol and env can be difficult, requiring manual work. ROL is a way of simplifying these tasks. Conclusion ROL provides 1. annotation and presentation of known retroviral sequences, 2. detection of proviral chains in unknown genomic sequences, with up to 100 Mbase per submission.

Use of retroviral-mediated gene transfer to deliver and test function of chimeric antigen receptors in human T-cells

Directory of Open Access Journals (Sweden)

Ana C. Parente-Pereira

2014-07-01

Full Text Available Chimeric antigen receptors (CARs are genetically delivered fusion molecules that elicit T-cell activation upon binding of a native cell surface molecule. These molecules can be used to generate a large number of memory and effector T-cells that are capable of recognizing and attacking tumor cells. Most commonly, stable CAR expression is achieved in T-cells using retroviral vectors. In the method described here, retroviral vectors are packaged in a two-step procedure. First, H29D human retroviral packaging cells (a derivative of 293 cells are transfected with the vector of interest, which is packaged transiently in vesicular stomatitis virus (VSV G pseudotyped particles. These particles are used to deliver the vector to PG13 cells, which achieve stable packaging of gibbon ape leukaemia virus (GALV-pseudotyped particles that are suitable for infection of human T-cells. The key advantage of the method reported here is that it robustly generates polyclonal PG13 cells that are 100% positive for the vector of interest. This means that efficient gene transfer may be repeatedly achieved without the need to clone individual PG13 cells for experimental pre-clinical testing. To achieve T-cell transduction, cells must first be activated using a non-specific mitogen. Phytohemagglutinin (PHA provides an economic and robust stimulus to achieve this. After 48-72 h, activated T-cells and virus-conditioned medium are mixed in RetroNectin-coated plasticware, which enhances transduction efficiency. Transduced cells are analyzed for gene transfer efficiency by flow cytometry 48 h following transduction and may then be tested in several assays to evaluate CAR function, including target-dependent cytotoxicity, cytokine production and proliferation.

Radical SAM, A Novel Protein Superfamily Linking Unresolved Steps in Familiar Biosynthetic Pathways with Radical Mechanisms: Functional Characterization Using New Analysis and Information Visualization Methods

Energy Technology Data Exchange (ETDEWEB)

Sofia, Heidi J.; Chen, Guang; Hetzler, Elizabeth G.; Reyes Spindola, Jorge F.; Miller, Nancy E.

2001-03-01

A large protein superfamily with over 500 members has been discovered and analyzed using powerful new bioinformatics and information visualization methods. Evidence exists that these proteins generate a 5?-deoxyadenosyl radical by reductive cleavage of S-adenosylmethionine (SAM) through an unusual Fe-S center. Radical SAM superfamily proteins function in DNA precursor, vitamin, cofactor, antibiotic, and herbicide biosynthesis in a collection of basic and familiar pathways. One of the members is interferon-inducible and is considered a candidate drug target for osteoporosis. The identification of this superfamily suggests that radical-based catalysis is important in a number of previously well-studied but unresolved biochemical pathways.

Meeting report - TGF-β superfamily: signaling in development and disease.

Science.gov (United States)

Zhang, Ying E; Newfeld, Stuart J

2013-11-01

The latest advances on the transforming growth factor β (TGF-β) and bone morphogenetic protein (BMP) signaling pathways were reported at the July 2013 FASEB Summer Research Conference 'The TGF-β Superfamily: Development and Disease'. The meeting was held in Steamboat Springs, Colorado, USA at 6700 feet above sea level in the Rocky Mountains. This was the seventh biannual meeting in the series. In attendance were investigators from a broad range of disciplines with a common interest in the mechanics of TGF-β and BMP signaling pathways, their normal developmental and homeostatic functions, and the diseases associated with pathway misregulation.

Diversification of a single ancestral gene into a successful toxin superfamily in highly venomous Australian funnel-web spiders.

Science.gov (United States)

Pineda, Sandy S; Sollod, Brianna L; Wilson, David; Darling, Aaron; Sunagar, Kartik; Undheim, Eivind A B; Kely, Laurence; Antunes, Agostinho; Fry, Bryan G; King, Glenn F

2014-03-05

Spiders have evolved pharmacologically complex venoms that serve to rapidly subdue prey and deter predators. The major toxic factors in most spider venoms are small, disulfide-rich peptides. While there is abundant evidence that snake venoms evolved by recruitment of genes encoding normal body proteins followed by extensive gene duplication accompanied by explosive structural and functional diversification, the evolutionary trajectory of spider-venom peptides is less clear. Here we present evidence of a spider-toxin superfamily encoding a high degree of sequence and functional diversity that has evolved via accelerated duplication and diversification of a single ancestral gene. The peptides within this toxin superfamily are translated as prepropeptides that are posttranslationally processed to yield the mature toxin. The N-terminal signal sequence, as well as the protease recognition site at the junction of the propeptide and mature toxin are conserved, whereas the remainder of the propeptide and mature toxin sequences are variable. All toxin transcripts within this superfamily exhibit a striking cysteine codon bias. We show that different pharmacological classes of toxins within this peptide superfamily evolved under different evolutionary selection pressures. Overall, this study reinforces the hypothesis that spiders use a combinatorial peptide library strategy to evolve a complex cocktail of peptide toxins that target neuronal receptors and ion channels in prey and predators. We show that the ω-hexatoxins that target insect voltage-gated calcium channels evolved under the influence of positive Darwinian selection in an episodic fashion, whereas the κ-hexatoxins that target insect calcium-activated potassium channels appear to be under negative selection. A majority of the diversifying sites in the ω-hexatoxins are concentrated on the molecular surface of the toxins, thereby facilitating neofunctionalisation leading to new toxin pharmacology.

Structure of TTHA1623, a novel metallo-β-lactamase superfamily protein from Thermus thermophilus HB8

International Nuclear Information System (INIS)

Yamamura, Akihiro; Okada, Akitoshi; Kameda, Yasuhiro; Ohtsuka, Jun; Nakagawa, Noriko; Ebihara, Akio; Nagata, Koji; Tanokura, Masaru

2009-01-01

The crystal structures of TTHA1623 from T. thermophilus HB8 in an iron-bound and a zinc-bound form have been determined to 2.8 and 2.2 Å resolution, respectively. TTHA1623 is a metallo-β-lactamase superfamily protein from the extremely thermophilic bacterium Thermus thermophilus HB8. Homologues of TTHA1623 exist in a wide range of bacteria and archaea and one eukaryote, Giardia lamblia, but their function remains unknown. To analyze the structural properties of TTHA1623, the crystal structures of its iron-bound and zinc-bound forms have been determined to 2.8 and 2.2 Å resolution, respectively. TTHA1623 possesses an αββα-fold similar to that of other metallo-β-lactamase superfamily proteins with glyoxalase II-type metal coordination. However, TTHA1623 exhibits a putative substrate-binding pocket with a unique shape

Isolation of a novel LPS-induced component of the ML superfamily in Ciona intestinalis.

Science.gov (United States)

Vizzini, Aiti; Bonura, Angela; Longo, Valeria; Sanfratello, Maria Antonietta; Parrinello, Daniela; Cammarata, Matteo; Colombo, Paolo

2015-11-01

ML superfamily represents a group of proteins playing important roles in lipid metabolism and innate immune response. In this study, we report the identification of the first component of the ML superfamily in the invertebrate Ciona intestinalis by means of a subtractive hybridization strategy. Sequence homology and phylogenetic analysis showed that this protein forms a specific clade with vertebrate components of the Niemann-Pick type C2 protein and, for this reason, it has been named Ci-NPC2. The putative Ci-NPC2 is a 150 amino acids long protein with a short signal peptide, seven cysteine residues, three putative lipid binding site and a three-dimensional model showing a characteristic β-strand structure. Gene expression analysis demonstrated that the Ci-NPC2 protein is positively upregulated after LPS inoculum with a peak of expression 1 h after challenge. Finally, in-situ hybridization demonstrated that the Ci-NPC2 protein is preferentially expressed in hemocytes inside the vessel lumen. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Structure of a Sugar Transporter of the Glucose EIIC Superfamily Provides Insight into the Elevator Mechanism of Membrane Transport.

Science.gov (United States)

McCoy, Jason G; Ren, Zhenning; Stanevich, Vitali; Lee, Jumin; Mitra, Sharmistha; Levin, Elena J; Poget, Sebastien; Quick, Matthias; Im, Wonpil; Zhou, Ming

2016-06-07

The phosphoenolpyruvate:carbohydrate phosphotransferase systems are found in bacteria, where they play central roles in sugar uptake and regulation of cellular uptake processes. Little is known about how the membrane-embedded components (EIICs) selectively mediate the passage of carbohydrates across the membrane. Here we report the functional characterization and 2.55-Å resolution structure of a maltose transporter, bcMalT, belonging to the glucose superfamily of EIIC transporters. bcMalT crystallized in an outward-facing occluded conformation, in contrast to the structure of another glucose superfamily EIIC, bcChbC, which crystallized in an inward-facing occluded conformation. The structures differ in the position of a structurally conserved substrate-binding domain that is suggested to play a central role in sugar transport. In addition, molecular dynamics simulations suggest a potential pathway for substrate entry from the periplasm into the bcMalT substrate-binding site. These results provide a mechanistic framework for understanding substrate recognition and translocation for the glucose superfamily EIIC transporters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural mutations of C-domains in members of the Ig superfamily. Consequences for the interactions between the T cell antigen receptor and the zeta 2 homodimer

DEFF Research Database (Denmark)

Geisler, C; Rubin, B; Caspar-Bauguil, S

1992-01-01

Several molecules belonging to the Ig superfamily are expressed together with noncovalently associated subunits. This applies for membrane-bound IgM and IgD, some of the FcR, and the Ti dimers of the TCR. The interactions between members of the Ig superfamily and their associated subunits are sti...

Production and characterization of a thermostable alcohol dehydrogenase that belongs to the aldo-keto reductase superfamily

NARCIS (Netherlands)

Machielsen, M.P.; Uria, A.R.; Kengen, S.W.M.; Oost, van der J.

2006-01-01

The gene encoding a novel alcohol dehydrogenase that belongs to the aldo-keto reductase superfamily has been identified in the hyperthermophilic archaeon Pyrococcus furiosus. The gene, referred to as adhD, was functionally expressed in Escherichia coli and subsequently purified to homogeneity. The

Evolution of Enzymatic Activities in the Enolase Superfamily: Stereochemically Distinct Mechanisms in Two Families of cis,cis-Muconate Lactonizing Enzymes

Energy Technology Data Exchange (ETDEWEB)

Sakai, A.; Fedorov, A; Fedorov, E; Schnoes, A; Glasner, M; Burley, S; Babbitt, P; Almo, S; Gerlt, J

2009-01-01

The mechanistically diverse enolase superfamily is a paradigm for elucidating Nature's strategies for divergent evolution of enzyme function. Each of the different reactions catalyzed by members of the superfamily is initiated by abstraction of the a-proton of a carboxylate substrate that is coordinated to an essential Mg2+. The muconate lactonizing enzyme (MLE) from Pseudomonas putida, a member of a family that catalyzes the syn-cycloisomerization of cis,cis-muconate to (4S)-muconolactone in the e-ketoadipate pathway, has provided critical insights into the structural bases for evolution of function within the superfamily. A second, divergent family of homologous MLEs that catalyzes anti-cycloisomerization has been identified. Structures of members of both families liganded with the common (4S)-muconolactone product (syn, Pseudomonas fluorescens, gi 70731221; anti, Mycobacterium smegmatis, gi 118470554) document that the conserved Lys at the end of the second e-strand in the (e/a)7e-barrel domain serves as the acid catalyst in both reactions. The different stereochemical courses (syn and anti) result from different structural strategies for determining substrate specificity: although the distal carboxylate group of the cis,cis-muconate substrate attacks the same face of the proximal double bond, opposite faces of the resulting enolate anion intermediate are presented to the conserved Lys acid catalyst. The discovery of two families of homologous, but stereochemically distinct, MLEs likely provides an example of 'pseudoconvergent' evolution of the same function from different homologous progenitors within the enolase superfamily, in which different spatial arrangements of active site functional groups and substrate specificity determinants support catalysis of the same reaction.

Evolution of Enzymatic Activities in the Enolase Superfamily: Stereochemically Distinct Mechanisms in Two Families of cis,cis-Muconate Lactonizing Enzymes†

Science.gov (United States)

Sakai, Ayano; Fedorov, Alexander A.; Fedorov, Elena V.; Schnoes, Alexandra M.; Glasner, Margaret E.; Brown, Shoshana; Rutter, Marc E.; Bain, Kevin; Chang, Shawn; Gheyi, Tarun; Sauder, J. Michael; Burley, Stephen K.; Babbitt, Patricia C.; Almo, Steven C.; Gerlt, John A.

2009-01-01

The mechanistically diverse enolase superfamily is a paradigm for elucidating Nature’s strategies for divergent evolution of enzyme function. Each of the different reactions catalyzed by members of the superfamily is initiated by abstraction of the α-proton of a carboxylate substrate that is coordinated to an essential Mg2+. The muconate lactonizing enzyme (MLE) from Pseudomonas putida, a member of a family that catalyzes the syn-cycloisomerization of cis,cis-muconate to (4S)-muconolactone in the β-ketoadipate pathway, has provided critical insights into the structural bases for evolution of function within the superfamily. A second, divergent family of homologues MLEs that catalyzes anti-cycloisomerization has been identified. Structures of members of both families liganded with the common (4S)-muconolactone product (syn, Pseudomonas fluorescens, GI:70731221; anti, Mycobacterium smegmatis, GI:118470554) document that the conserved Lys at the end of the second β-strand in the (β/α)7β-barrel domain serves as the acid catalyst in both reactions. The different stereochemical courses (syn and anti) result from different structural strategies for determining substrate specificity: although the distal carboxylate group of the cis,cis-muconate substrate attacks the same face of the proximal double bond, opposite faces of the resulting enolate anion intermediate are presented to the conserved Lys acid catalyst. The discovery of two families of homologous, but stereochemically distinct, MLEs likely provides an example of “pseudoconvergent” evolution of the same function from different homologous progenitors within the enolase superfamily, in which different spatial arrangements of active site functional groups and substrate specificity determinants support catalysis of the same reaction. PMID:19220063

Characterization of an internal ribosomal entry segment within the 5' leader of avian reticuloendotheliosis virus type A RNA and development of novel MLV-REV-based retroviral vectors.

Science.gov (United States)

López-Lastra, M; Gabus, C; Darlix, J L

1997-11-01

The murine leukemia virus (MLV)-related type C viruses constitute a major class of retroviruses that includes numerous endogenous and exogenous mammalian viruses and the related avian spleen necrosis virus (SNV). The MLV-related viruses possess a long and multifunctional 5' untranslated leader involved in key steps of the viral life cycle--splicing, translation, RNA dimerization, encapsidation, and reverse transcription. Recent studies have shown that the 5' leader of Friend murine leukemia virus and Moloney murine leukemia virus can direct cap independent translation of gag precursor proteins (Berlioz et al., 1995; Vagner et al., 1995b). These data, together with structural homology studies (Koning et al., 1992), prompted us to undertake a search for new internal ribosome entry segment (IRES) of retroviral origin. Here we describe an IRES element within the 5' leader of avian reticuloendotheliosis virus type A (REV-A) genomic RNA. Data show that the REV-A 5' IRES element maps downstream of the packaging/dimerization (E/DLS) sequence (Watanabe and Temin, 1982; Darlix et al., 1992) and the minimal IRES sequence appears to be within a 129 nt fragment (nucleotides 452-580) of the 5' leader, immediately upstream of the gag AUG codon. The REV-A IRES has been successfully utilized in the construction of novel high titer MLV-based retroviral vectors, containing one or more IRES elements of retroviral origin. These retroviral constructs, which represent a starting point for the design of novel vectors suitable for gene therapy, are also of interest as a model system of internal translation initiation and its possible regulation during development, cancer, or virus infection.

Genome-wide analysis of the expansin gene superfamily reveals grapevine-specific structural and functional characteristics.

Directory of Open Access Journals (Sweden)

Silvia Dal Santo

Full Text Available BACKGROUND: Expansins are proteins that loosen plant cell walls in a pH-dependent manner, probably by increasing the relative movement among polymers thus causing irreversible expansion. The expansin superfamily (EXP comprises four distinct families: expansin A (EXPA, expansin B (EXPB, expansin-like A (EXLA and expansin-like B (EXLB. There is experimental evidence that EXPA and EXPB proteins are required for cell expansion and developmental processes involving cell wall modification, whereas the exact functions of EXLA and EXLB remain unclear. The complete grapevine (Vitis vinifera genome sequence has allowed the characterization of many gene families, but an exhaustive genome-wide analysis of expansin gene expression has not been attempted thus far. METHODOLOGY/PRINCIPAL FINDINGS: We identified 29 EXP superfamily genes in the grapevine genome, representing all four EXP families. Members of the same EXP family shared the same exon-intron structure, and phylogenetic analysis confirmed a closer relationship between EXP genes from woody species, i.e. grapevine and poplar (Populus trichocarpa, compared to those from Arabidopsis thaliana and rice (Oryza sativa. We also identified grapevine-specific duplication events involving the EXLB family. Global gene expression analysis confirmed a strong correlation among EXP genes expressed in mature and green/vegetative samples, respectively, as reported for other gene families in the recently-published grapevine gene expression atlas. We also observed the specific co-expression of EXLB genes in woody organs, and the involvement of certain grapevine EXP genes in berry development and post-harvest withering. CONCLUSION: Our comprehensive analysis of the grapevine EXP superfamily confirmed and extended current knowledge about the structural and functional characteristics of this gene family, and also identified properties that are currently unique to grapevine expansin genes. Our data provide a model for the

GFP-like proteins as ubiquitous metazoan superfamily: evolution of functional features and structural complexity.

Science.gov (United States)

Shagin, Dmitry A; Barsova, Ekaterina V; Yanushevich, Yurii G; Fradkov, Arkady F; Lukyanov, Konstantin A; Labas, Yulii A; Semenova, Tatiana N; Ugalde, Juan A; Meyers, Ann; Nunez, Jose M; Widder, Edith A; Lukyanov, Sergey A; Matz, Mikhail V

2004-05-01

Homologs of the green fluorescent protein (GFP), including the recently described GFP-like domains of certain extracellular matrix proteins in Bilaterian organisms, are remarkably similar at the protein structure level, yet they often perform totally unrelated functions, thereby warranting recognition as a superfamily. Here we describe diverse GFP-like proteins from previously undersampled and completely new sources, including hydromedusae and planktonic Copepoda. In hydromedusae, yellow and nonfluorescent purple proteins were found in addition to greens. Notably, the new yellow protein seems to follow exactly the same structural solution to achieving the yellow color of fluorescence as YFP, an engineered yellow-emitting mutant variant of GFP. The addition of these new sequences made it possible to resolve deep-level phylogenetic relationships within the superfamily. Fluorescence (most likely green) must have already existed in the common ancestor of Cnidaria and Bilateria, and therefore GFP-like proteins may be responsible for fluorescence and/or coloration in virtually any animal. At least 15 color diversification events can be inferred following the maximum parsimony principle in Cnidaria. Origination of red fluorescence and nonfluorescent purple-blue colors on several independent occasions provides a remarkable example of convergent evolution of complex features at the molecular level.

Building a Phylogenetic Tree of the Human and Ape Superfamily Using DNA-DNA Hybridization Data

Science.gov (United States)

Maier, Caroline Alexander

2004-01-01

The study describes the process of DNA-DNA hybridization and the history of its use by Sibley and Alquist in simple, straightforward, and interesting language that students easily understand to create their own phylogenetic tree of the hominoid superfamily. They calibrate the DNA clock and use it to estimate the divergence dates of the various…

Retroviral Vectors for Analysis of Viral Mutagenesis and Recombination

Directory of Open Access Journals (Sweden)

Jonathan M.O. Rawson

2014-09-01

Full Text Available Retrovirus population diversity within infected hosts is commonly high due in part to elevated rates of replication, mutation, and recombination. This high genetic diversity often complicates the development of effective diagnostics, vaccines, and antiviral drugs. This review highlights the diverse vectors and approaches that have been used to examine mutation and recombination in retroviruses. Retroviral vectors for these purposes can broadly be divided into two categories: those that utilize reporter genes as mutation or recombination targets and those that utilize viral genes as targets of mutation or recombination. Reporter gene vectors greatly facilitate the detection, quantification, and characterization of mutants and/or recombinants, but may not fully recapitulate the patterns of mutagenesis or recombination observed in native viral gene sequences. In contrast, the detection of mutations or recombination events directly in viral genes is more biologically relevant but also typically more challenging and inefficient. We will highlight the advantages and disadvantages of the various vectors and approaches used as well as propose ways in which they could be improved.

The Host RNAs in Retroviral Particles

Directory of Open Access Journals (Sweden)

Alice Telesnitsky

2016-08-01

Full Text Available As they assemble, retroviruses encapsidate both their genomic RNAs and several types of host RNA. Whereas limited amounts of messenger RNA (mRNA are detectable within virion populations, the predominant classes of encapsidated host RNAs do not encode proteins, but instead include endogenous retroelements and several classes of non-coding RNA (ncRNA, some of which are packaged in significant molar excess to the viral genome. Surprisingly, although the most abundant host RNAs in retroviruses are also abundant in cells, unusual forms of these RNAs are packaged preferentially, suggesting that these RNAs are recruited early in their biogenesis: before associating with their cognate protein partners, and/or from transient or rare RNA populations. These RNAs’ packaging determinants differ from the viral genome’s, and several of the abundantly packaged host ncRNAs serve cells as the scaffolds of ribonucleoprotein particles. Because virion assembly is equally efficient whether or not genomic RNA is available, yet RNA appears critical to the structural integrity of retroviral particles, it seems possible that the selectively encapsidated host ncRNAs might play roles in assembly. Indeed, some host ncRNAs appear to act during replication, as some transfer RNA (tRNA species may contribute to nuclear import of human immunodeficiency virus 1 (HIV-1 reverse transcription complexes, and other tRNA interactions with the viral Gag protein aid correct trafficking to plasma membrane assembly sites. However, despite high conservation of packaging for certain host RNAs, replication roles for most of these selectively encapsidated RNAs—if any—have remained elusive.

Analyzing the Genotoxicity of Retroviral Vectors in Hematopoietic Cell Gene Therapy

Directory of Open Access Journals (Sweden)

Luca Biasco

2018-03-01

Full Text Available Retroviral vectors, including those derived from gammaretroviruses and lentiviruses, have found their way into the clinical arena and demonstrated remarkable efficacy for the treatment of immunodeficiencies, leukodystrophies, and globinopathies. Despite these successes, gene therapy unfortunately also has had to face severe adverse events in the form of leukemias and myelodysplastic syndromes, related to the semi-random vector integration into the host cell genome that caused deregulation of neighboring proto-oncogenes. Although improvements in vector design clearly lowered the risk of this insertional mutagenesis, analysis of potential genotoxicity and the consequences of vector integration remain important parameters for basic and translational research and most importantly for the clinic. Here, we review current assays to analyze biodistribution and genotoxicity in the pre-clinical setting and describe tools to monitor vector integration sites in vector-treated patients as a biosafety readout.

The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome.

Directory of Open Access Journals (Sweden)

Nikki van Bel

Full Text Available The viral integrase (IN is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs. Although designed to interfere with the IN-LEDGF/p75 interaction to block HIV DNA integration during the early phase of HIV-1 replication, the major impact was surprisingly found on the process of virus maturation during the late phase, causing a reverse transcription defect upon infection of target cells. Virus particles produced in the presence of an ALLINI are misformed with the ribonucleoprotein located outside the virus core. Virus assembly and maturation are highly orchestrated and regulated processes in which several viral proteins and RNA molecules closely interact. It is therefore of interest to study whether ALLINIs have unpredicted pleiotropic effects on these RNA-related processes. We confirm that the ALLINI BI-D inhibits virus replication and that the produced virus is non-infectious. Furthermore, we show that the wild-type level of HIV-1 genomic RNA is packaged in virions and these genomes are in a dimeric state. The tRNAlys3 primer for reverse transcription was properly placed on this genomic RNA and could be extended ex vivo. In addition, the packaged reverse transcriptase enzyme was fully active when extracted from virions. As the RNA and enzyme components for reverse transcription are properly present in virions produced in the presence of BI-D, the inhibition of reverse transcription is likely to reflect the mislocalization of the components in the aberrant virus particle.

The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome.

Science.gov (United States)

van Bel, Nikki; van der Velden, Yme; Bonnard, Damien; Le Rouzic, Erwann; Das, Atze T; Benarous, Richard; Berkhout, Ben

2014-01-01

The viral integrase (IN) is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs). Although designed to interfere with the IN-LEDGF/p75 interaction to block HIV DNA integration during the early phase of HIV-1 replication, the major impact was surprisingly found on the process of virus maturation during the late phase, causing a reverse transcription defect upon infection of target cells. Virus particles produced in the presence of an ALLINI are misformed with the ribonucleoprotein located outside the virus core. Virus assembly and maturation are highly orchestrated and regulated processes in which several viral proteins and RNA molecules closely interact. It is therefore of interest to study whether ALLINIs have unpredicted pleiotropic effects on these RNA-related processes. We confirm that the ALLINI BI-D inhibits virus replication and that the produced virus is non-infectious. Furthermore, we show that the wild-type level of HIV-1 genomic RNA is packaged in virions and these genomes are in a dimeric state. The tRNAlys3 primer for reverse transcription was properly placed on this genomic RNA and could be extended ex vivo. In addition, the packaged reverse transcriptase enzyme was fully active when extracted from virions. As the RNA and enzyme components for reverse transcription are properly present in virions produced in the presence of BI-D, the inhibition of reverse transcription is likely to reflect the mislocalization of the components in the aberrant virus particle.

Inorganic and organic fertilizers impact the abundance and proportion of antibiotic resistance and integron-integrase genes in agricultural grassland soil.

Science.gov (United States)

Nõlvak, Hiie; Truu, Marika; Kanger, Kärt; Tampere, Mailiis; Espenberg, Mikk; Loit, Evelin; Raave, Henn; Truu, Jaak

2016-08-15

Soil fertilization with animal manure or its digestate may facilitate an important antibiotic resistance dissemination route from anthropogenic sources to the environment. This study examines the effect of mineral fertilizer (NH4NO3), cattle slurry and cattle slurry digestate amendment on the abundance and proportion dynamics of five antibiotic resistance genes (ARGs) and two classes of integron-integrase genes (intI1 and intI2) in agricultural grassland soil. Fertilization was performed thrice throughout one vegetation period. The targeted ARGs (sul1, tetA, blaCTX-M, blaOXA2 and qnrS) encode resistance to several major antibiotic classes used in veterinary medicine such as sulfonamides, tetracycline, cephalosporins, penicillin and fluoroquinolones, respectively. The non-fertilized grassland soil contained a stable background of tetA, blaCTX-M and sul1 genes. The type of applied fertilizer significantly affected ARGs and integron-integrase genes abundances and proportions in the bacterial community (porganic fertilizer's application event, but this increase was followed by a stage of decrease, suggesting that microbes possessing these genes were predominantly entrained into soil via cattle slurry or its digestate application and had somewhat limited survival potential in a soil environment. However, the abundance of these three target genes did not decrease to a background level by the end of the study period. TetA was most abundant in mineral fertilizer treated soil and blaCTX-M in cattle slurry digestate amended soil. Despite significantly different abundances, the abundance dynamics of bacteria possessing these genes were similar (p<0.05 in all cases) in different treatments and resembled the dynamics of the whole bacterial community abundance in each soil treatment. Copyright © 2016. Published by Elsevier B.V.

Subdivision of the MDR superfamily of medium-chain dehydrogenases/reductases through iterative hidden Markov model refinement

Directory of Open Access Journals (Sweden)

Persson Bengt

2010-10-01

Full Text Available Abstract Background The Medium-chain Dehydrogenases/Reductases (MDR form a protein superfamily whose size and complexity defeats traditional means of subclassification; it currently has over 15000 members in the databases, the pairwise sequence identity is typically around 25%, there are members from all kingdoms of life, the chain-lengths vary as does the oligomericity, and the members are partaking in a multitude of biological processes. There are profile hidden Markov models (HMMs available for detecting MDR superfamily members, but none for determining which MDR family each protein belongs to. The current torrential influx of new sequence data enables elucidation of more and more protein families, and at an increasingly fine granularity. However, gathering good quality training data usually requires manual attention by experts and has therefore been the rate limiting step for expanding the number of available models. Results We have developed an automated algorithm for HMM refinement that produces stable and reliable models for protein families. This algorithm uses relationships found in data to generate confident seed sets. Using this algorithm we have produced HMMs for 86 distinct MDR families and 34 of their subfamilies which can be used in automated annotation of new sequences. We find that MDR forms with 2 Zn2+ ions in general are dehydrogenases, while MDR forms with no Zn2+ in general are reductases. Furthermore, in Bacteria MDRs without Zn2+ are more frequent than those with Zn2+, while the opposite is true for eukaryotic MDRs, indicating that Zn2+ has been recruited into the MDR superfamily after the initial life kingdom separations. We have also developed a web site http://mdr-enzymes.org that provides textual and numeric search against various characterised MDR family properties, as well as sequence scan functions for reliable classification of novel MDR sequences. Conclusions Our method of refinement can be readily applied to

Phosphatidylcholine Transfer Protein Interacts with Thioesterase Superfamily Member 2 to Attenuate Insulin Signaling

OpenAIRE

Ersoy, Baran A.; Tarun, Akansha; D’Aquino, Katharine; Hancer, Nancy J.; Ukomadu, Chinweike; White, Morris F.; Michel, Thomas; Manning, Brendan D.; Cohen, David E.

2013-01-01

Phosphatidylcholine transfer protein (PC-TP) is a phospholipid-binding protein that is enriched in liver and that interacts with thioesterase superfamily member 2 (THEM2). Mice lacking either protein exhibit improved hepatic glucose homeostasis and are resistant to diet-induced diabetes. Insulin receptor substrate 2 (IRS2) and mammalian target of rapamycin complex 1 (mTORC1) are key effectors of insulin signaling, which is attenuated in diabetes. We found that PC-TP inhibited IRS2, as evidenc...

Crystallization and preliminary X-ray studies of TON-1713 from Thermococcus onnurineus NA1, a putative member of the haloacid dehalogenase superfamily

International Nuclear Information System (INIS)

Le, Binh Van; Lee, Hyun Sook; Cho, Yona; Kang, Sung Gyun; Kim, Dong Young; Kim, Yang-Gyun; Kim, Kyeong Kyu

2007-01-01

A putative member of the haloacid dehalogenase superfamily from T. onnurineus has been expressed, purified and crystallized using 1.6 M magnesium sulfate as a precipitant. The crystals belonged to the triclinic space group P1 and diffracted to 1.8 Å resolution. The haloacid dehalogenase (HAD) protein superfamily is one of the largest enzyme families and shows hydrolytic activity towards diverse substrates. Structural analyses of enzymes belonging to the HAD family are required to elucidate the molecular basis underlying their broad substrate specificity and reaction mechanism. For this purpose, TON-1713, a hypothetical protein from Thermococcus onnurineus that is a member of the HAD superfamily, was expressed in Escherichia coli, purified and crystallized at 295 K using 1.6 M magnesium sulfate as a precipitant. X-ray diffraction data were collected to 1.8 Å resolution using a synchrotron-radiation source. The crystals belong to the triclinic space group P1, with unit-cell parameters a = 52.5, b = 65.8, c = 203.4 Å, α = 71.1, β = 79.9, γ = 74.3°

Protection of hematopoietic cells from O(6)-alkylation damage by O(6)-methylguanine DNA methyltransferase gene transfer: studies with different O(6)-alkylating agents and retroviral backbones.

Science.gov (United States)

Jansen, M; Bardenheuer, W; Sorg, U R; Seeber, S; Flasshove, M; Moritz, T

2001-07-01

Overexpression of O(6)-methylguanine DNA methyltransferase (MGMT) can protect hematopoietic cells from O(6)-alkylation damage. To identify possible clinical applications of this technology we compared the effect of MGMT gene transfer on the hematotoxicity induced by different O(6)-alkylating agents in clinical use: the chloroethylnitrosoureas ACNU, BCNU, CCNU and the tetrazine derivative temozolomide. In addition, various retroviral vectors expressing the MGMT-cDNA were investigated to identify optimal viral backbones for hematoprotection by MGMT expression. Protection from ACNU, BCNU, CCNU or temozolomide toxicity was evaluated utilizing a Moloney murine leukemia virus-based retroviral vector (N2/Zip-PGK-MGMT) to transduce primary murine bone marrow cells. Increased resistance in murine colony-forming units (CFU) was demonstrated for all four drugs. In comparison to mock-transduced controls, after transduction with N2/Zip-PGK-MGMT the IC50 for CFU increased on average 4.7-fold for ACNU, 2.5-fold for BCNU, 6.3-fold for CCNU and 1.5-fold for temozolomide. To study the effect of the retroviral backbone on hematoprotection various vectors expressing the human MGMT-cDNA from a murine embryonic sarcoma virus LTR (MSCV-MGMT) or a hybrid spleen focus-forming/murine embryonic sarcoma virus LTR (SF1-MGMT) were compared with the N2/Zip-PGK-MGMT vector. While all vectors increased resistance of transduced human CFU to ACNU, the SF1-MGMT construct was most efficient especially at high ACNU concentrations (8-12 microg/ml). Similar results were obtained for protection of murine high-proliferative-potential colony-forming cells. These data may help to optimize treatment design and retroviral constructs in future clinical studies aiming at hematoprotection by MGMT gene transfer.

Immunoglobulin superfamily members encoded by viruses and their multiple roles in immune evasion.

Science.gov (United States)

Farré, Domènec; Martínez-Vicente, Pablo; Engel, Pablo; Angulo, Ana

2017-05-01

Pathogens have developed a plethora of strategies to undermine host immune defenses in order to guarantee their survival. For large DNA viruses, these immune evasion mechanisms frequently rely on the expression of genes acquired from host genomes. Horizontally transferred genes include members of the immunoglobulin superfamily, whose products constitute the most diverse group of proteins of vertebrate genomes. Their promiscuous immunoglobulin domains, which comprise the building blocks of these molecules, are involved in a large variety of functions mediated by ligand-binding interactions. The flexible structural nature of the immunoglobulin domains makes them appealing targets for viral capture due to their capacity to generate high functional diversity. Here, we present an up-to-date review of immunoglobulin superfamily gene homologs encoded by herpesviruses, poxviruses, and adenoviruses, that include CD200, CD47, Fc receptors, interleukin-1 receptor 2, interleukin-18 binding protein, CD80, carcinoembryonic antigen-related cell adhesion molecules, and signaling lymphocyte activation molecules. We discuss their distinct structural attributes, binding properties, and functions, shaped by evolutionary pressures to disarm specific immune pathways. We include several novel genes identified from extensive genome database surveys. An understanding of the properties and modes of action of these viral proteins may guide the development of novel immune-modulatory therapeutic tools. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evolutionary Pattern of N-Glycosylation Sequon Numbers  in Eukaryotic ABC Protein Superfamilies

Directory of Open Access Journals (Sweden)

R. Shyama Prasad Rao

2010-02-01

Full Text Available Many proteins contain a large number of NXS/T sequences (where X is any amino acid except proline which are the potential sites of asparagine (N linked glycosylation. However, the patterns of occurrence of these N-glycosylation sequons in related proteins or groups of proteins and their underlying causes have largely been unexplored. We computed the actual and probabilistic occurrence of NXS/T sequons in ABC protein superfamilies from eight diverse eukaryotic organisms. The ABC proteins contained significantly higher NXS/T sequon numbers compared to respective genome-wide average, but the sequon density was significantly lower owing to the increase in protein size and decrease in sequon specific amino acids. However, mammalian ABC proteins have significantly higher sequon density, and both serine and threonine containing sequons (NXS and NXT have been positively selected—against the recent findings of only threonine specific Darwinian selection of sequons in proteins. The occurrence of sequons was positively correlated with the frequency of sequon specific amino acids and negatively correlated with proline and the NPS/T sequences. Further, the NPS/T sequences were significantly higher than expected in plant ABC proteins which have the lowest number of NXS/T sequons. Accord- ingly, compared to overall proteins, N-glycosylation sequons in ABC protein superfamilies have a distinct pattern of occurrence, and the results are discussed in an evolutionary perspective.

Correction of glucocerebrosidase deficiency after retroviral-mediated gene transfer into hematopoietic progenitor cells from patients with Gaucher disease

International Nuclear Information System (INIS)

Fink, J.K.; Correll, P.H.; Perry, L.K.; Brady, R.O.; Karlsson, S.

1990-01-01

Retroviral gene transfer has been used successfully to correct the glucocerebrosidase (GCase) deficiency in primary hematopoietic cells from patients with Gaucher disease. For this model of somatic gene therapy, the authors developed a high-titer, amphotropic retroviral vector designated NTG in which the human GCase gene was driven by the mutant polyoma virus enhancer/herpesvirus thymidine kinase gene (tk) promoter (Py + /Htk). NTG normalized GCase activity in transduced Gaucher fibroblasts and efficiently infected human monocytic and erythroleukemic cell lines. RNA blot-hybridization (Northern blot) analysis of these hemaptopoietic cell lines showed unexpectedly high-level expression from the Moloney murine leukemia virus long terminal repeat (Mo-MLV LTR) and levels of Py + /Htk enhancer/promoter-initiated human GCase RNA that approximated endogenous GCase RNA levels. Furthermore, NTG efficiently infected human hematopoietic progenitor cells. Detection of the provirus in approximately one-third of NTG-infected progenitor colonies that had not been selected in G418-containing medium indicates that relative resistance to G418 underestimated the actual gene transfer efficiency. Northern blot analysis of NTG-infected, progenitor-derived cells showed expression from both the Mo-MLV LTR and the Py + /Htk enhancer/promoter. NTG-transduced hematopoietic progenitor cells from patients with Gaucher disease generated progeny in which GCase activity has been normalized

Correction of glucocerebrosidase deficiency after retroviral-mediated gene transfer into hematopoietic progenitor cells from patients with Gaucher disease

Energy Technology Data Exchange (ETDEWEB)

Fink, J.K.; Correll, P.H.; Perry, L.K.; Brady, R.O.; Karlsson, S. (National Institutes of Health, Bethesda, MD (USA))

1990-03-01

Retroviral gene transfer has been used successfully to correct the glucocerebrosidase (GCase) deficiency in primary hematopoietic cells from patients with Gaucher disease. For this model of somatic gene therapy, the authors developed a high-titer, amphotropic retroviral vector designated NTG in which the human GCase gene was driven by the mutant polyoma virus enhancer/herpesvirus thymidine kinase gene (tk) promoter (Py{sup +}/Htk). NTG normalized GCase activity in transduced Gaucher fibroblasts and efficiently infected human monocytic and erythroleukemic cell lines. RNA blot-hybridization (Northern blot) analysis of these hemaptopoietic cell lines showed unexpectedly high-level expression from the Moloney murine leukemia virus long terminal repeat (Mo-MLV LTR) and levels of Py{sup +}/Htk enhancer/promoter-initiated human GCase RNA that approximated endogenous GCase RNA levels. Furthermore, NTG efficiently infected human hematopoietic progenitor cells. Detection of the provirus in approximately one-third of NTG-infected progenitor colonies that had not been selected in G418-containing medium indicates that relative resistance to G418 underestimated the actual gene transfer efficiency. Northern blot analysis of NTG-infected, progenitor-derived cells showed expression from both the Mo-MLV LTR and the Py{sup +}/Htk enhancer/promoter. NTG-transduced hematopoietic progenitor cells from patients with Gaucher disease generated progeny in which GCase activity has been normalized.

Expression of TGF-beta superfamily growth factors, their receptors, the associated SMADs and antagonists in five isolated size-matched populations of pre-antral follicles from normal human ovaries

DEFF Research Database (Denmark)

Kristensen, Stine Gry; Andersen, Kasper; Clement, Christian Alexandro

2014-01-01

In mammals, members of the transforming growth factor-beta (TGF-β) superfamily are known to have key roles in the regulation of follicular growth and development. The aim of the study was to evaluate the expression of TGF-β superfamily growth factors, their receptors, downstream SMAD signalling m...... growth. Moreover, the presence of multiple TGF-β/BMP antagonists imply that certain growth factors are subjected to local regulation on different levels which address another important level of intraovarian regulation of follicle development in humans.......In mammals, members of the transforming growth factor-beta (TGF-β) superfamily are known to have key roles in the regulation of follicular growth and development. The aim of the study was to evaluate the expression of TGF-β superfamily growth factors, their receptors, downstream SMAD signalling...... molecules and TGF- β/BMP antagonists during early human folliculogenesis.Human preantral follicles were enzymatically isolated from surplus ovarian tissue obtained from women having ovarian cortical tissue frozen for fertility preservation. A total of 348 human preantral follicles, ranging from 40 to 200 µm...

A Survey of the ATP-Binding Cassette (ABC) Gene Superfamily in the Salmon Louse (Lepeophtheirus salmonis).

Science.gov (United States)

Carmona-Antoñanzas, Greta; Carmichael, Stephen N; Heumann, Jan; Taggart, John B; Gharbi, Karim; Bron, James E; Bekaert, Michaël; Sturm, Armin

2015-01-01

Salmon lice, Lepeophtheirus salmonis (Krøyer, 1837), are fish ectoparasites causing significant economic damage in the mariculture of Atlantic salmon, Salmo salar Linnaeus, 1758. The control of L. salmonis at fish farms relies to a large extent on treatment with anti-parasitic drugs. A problem related to chemical control is the potential for development of resistance, which in L. salmonis is documented for a number of drug classes including organophosphates, pyrethroids and avermectins. The ATP-binding cassette (ABC) gene superfamily is found in all biota and includes a range of drug efflux transporters that can confer drug resistance to cancers and pathogens. Furthermore, some ABC transporters are recognised to be involved in conferral of insecticide resistance. While a number of studies have investigated ABC transporters in L. salmonis, no systematic analysis of the ABC gene family exists for this species. This study presents a genome-wide survey of ABC genes in L. salmonis for which, ABC superfamily members were identified through homology searching of the L. salmonis genome. In addition, ABC proteins were identified in a reference transcriptome of the parasite generated by high-throughput RNA sequencing (RNA-seq) of a multi-stage RNA library. Searches of both genome and transcriptome allowed the identification of a total of 33 genes / transcripts coding for ABC proteins, of which 3 were represented only in the genome and 4 only in the transcriptome. Eighteen sequences were assigned to ABC subfamilies known to contain drug transporters, i.e. subfamilies B (4 sequences), C (11) and G (2). The results suggest that the ABC gene family of L. salmonis possesses fewer members than recorded for other arthropods. The present survey of the L. salmonis ABC gene superfamily will provide the basis for further research into potential roles of ABC transporters in the toxicity of salmon delousing agents and as potential mechanisms of drug resistance.

Evolutionary history and stress regulation of the lectin superfamily in higher plants

Directory of Open Access Journals (Sweden)

Ramachandran Srinivasan

2010-03-01

Full Text Available Abstract Background Lectins are a class of carbohydrate-binding proteins. They play roles in various biological processes. However, little is known about their evolutionary history and their functions in plant stress regulation. The availability of full genome sequences from various plant species makes it possible to perform a whole-genome exploration for further understanding their biological functions. Results Higher plant genomes encode large numbers of lectin proteins. Based on their domain structures and phylogenetic analyses, a new classification system has been proposed. In this system, 12 different families have been classified and four of them consist of recently identified plant lectin members. Further analyses show that some of lectin families exhibit species-specific expansion and rapid birth-and-death evolution. Tandem and segmental duplications have been regarded as the major mechanisms to drive lectin expansion although retrogenes also significantly contributed to the birth of new lectin genes in soybean and rice. Evidence shows that lectin genes have been involved in biotic/abiotic stress regulations and tandem/segmental duplications may be regarded as drivers for plants to adapt various environmental stresses through duplication followed by expression divergence. Each member of this gene superfamily may play specialized roles in a specific stress condition and function as a regulator of various environmental factors such as cold, drought and high salinity as well as biotic stresses. Conclusions Our studies provide a new outline of the plant lectin gene superfamily and advance the understanding of plant lectin genes in lineage-specific expansion and their functions in biotic/abiotic stress-related developmental processes.

Annotation error in public databases: misannotation of molecular function in enzyme superfamilies.

Directory of Open Access Journals (Sweden)

Alexandra M Schnoes

2009-12-01

Full Text Available Due to the rapid release of new data from genome sequencing projects, the majority of protein sequences in public databases have not been experimentally characterized; rather, sequences are annotated using computational analysis. The level of misannotation and the types of misannotation in large public databases are currently unknown and have not been analyzed in depth. We have investigated the misannotation levels for molecular function in four public protein sequence databases (UniProtKB/Swiss-Prot, GenBank NR, UniProtKB/TrEMBL, and KEGG for a model set of 37 enzyme families for which extensive experimental information is available. The manually curated database Swiss-Prot shows the lowest annotation error levels (close to 0% for most families; the two other protein sequence databases (GenBank NR and TrEMBL and the protein sequences in the KEGG pathways database exhibit similar and surprisingly high levels of misannotation that average 5%-63% across the six superfamilies studied. For 10 of the 37 families examined, the level of misannotation in one or more of these databases is >80%. Examination of the NR database over time shows that misannotation has increased from 1993 to 2005. The types of misannotation that were found fall into several categories, most associated with "overprediction" of molecular function. These results suggest that misannotation in enzyme superfamilies containing multiple families that catalyze different reactions is a larger problem than has been recognized. Strategies are suggested for addressing some of the systematic problems contributing to these high levels of misannotation.

Annotation error in public databases: misannotation of molecular function in enzyme superfamilies.

Science.gov (United States)

Schnoes, Alexandra M; Brown, Shoshana D; Dodevski, Igor; Babbitt, Patricia C

2009-12-01

Due to the rapid release of new data from genome sequencing projects, the majority of protein sequences in public databases have not been experimentally characterized; rather, sequences are annotated using computational analysis. The level of misannotation and the types of misannotation in large public databases are currently unknown and have not been analyzed in depth. We have investigated the misannotation levels for molecular function in four public protein sequence databases (UniProtKB/Swiss-Prot, GenBank NR, UniProtKB/TrEMBL, and KEGG) for a model set of 37 enzyme families for which extensive experimental information is available. The manually curated database Swiss-Prot shows the lowest annotation error levels (close to 0% for most families); the two other protein sequence databases (GenBank NR and TrEMBL) and the protein sequences in the KEGG pathways database exhibit similar and surprisingly high levels of misannotation that average 5%-63% across the six superfamilies studied. For 10 of the 37 families examined, the level of misannotation in one or more of these databases is >80%. Examination of the NR database over time shows that misannotation has increased from 1993 to 2005. The types of misannotation that were found fall into several categories, most associated with "overprediction" of molecular function. These results suggest that misannotation in enzyme superfamilies containing multiple families that catalyze different reactions is a larger problem than has been recognized. Strategies are suggested for addressing some of the systematic problems contributing to these high levels of misannotation.

An orphan viral TNF receptor superfamily member identified in lymphocystis disease virus.

Science.gov (United States)

Pontejo, Sergio M; Sánchez, Carolina; Martín, Rocío; Mulero, Victoriano; Alcami, Antonio; Alejo, Alí

2013-06-07

Lymphocystis disease virus (LCDV) is a large icosahedral dsDNA-containing virus of the Lymphocystivirus genus within the Iridoviridae family that can cause disease in more than 140 marine and freshwater fish species. While several isolates have been charcaterized and classified into distinct genotypes the complete genomic sequence is currently only available from two species, the LCDV-1, isolated from flounder (Platichtys flesus) in Europe and the LCDV-C, isolated from Japanese cultured flounder (Paralichthys olivaceus) in China. Analysis of the genome of LCDV-C showed it to encode a protein named LDVICp016 with similarities to the Tumour necrosis factor receptor (TNFR) superfamily with immunomodulatory potential. We have expressed and purified the recombinant protein LDVICp016 and screened for potential interaction partners using surface plasmon resonance. Commercially available human and mouse members of the TNF superfamily (TNFSF), along with a representative set of fish-derived TNFSF were tested.We have found the LDVICp016 protein to be secreted and we have identified a second viral TNFR encoded by ORF 095 of the same virus. None of the 42 tested proteins were found to interact with LDVICp016. We show that LDVICp016 is a secreted protein belonging to the TNF receptor family that may be part of a larger gene family in Lymphocystiviruses. While the ligand of this protein remains unknown, possibly due to the species specific nature of this interaction, further investigations into the potential role of this protein in the blockade of immune responses in its fish host are required.

Molecular modeling study on the allosteric inhibition mechanism of HIV-1 integrase by LEDGF/p75 binding site inhibitors.

Directory of Open Access Journals (Sweden)

Weiwei Xue

Full Text Available HIV-1 integrase (IN is essential for the integration of viral DNA into the host genome and an attractive therapeutic target for developing antiretroviral inhibitors. LEDGINs are a class of allosteric inhibitors targeting LEDGF/p75 binding site of HIV-1 IN. Yet, the detailed binding mode and allosteric inhibition mechanism of LEDGINs to HIV-1 IN is only partially understood, which hinders the structure-based design of more potent anti-HIV agents. A molecular modeling study combining molecular docking, molecular dynamics simulation, and binding free energy calculation were performed to investigate the interaction details of HIV-1 IN catalytic core domain (CCD with two recently discovered LEDGINs BI-1001 and CX14442, as well as the LEDGF/p75 protein. Simulation results demonstrated the hydrophobic domain of BI-1001 and CX14442 engages one subunit of HIV-1 IN CCD dimer through hydrophobic interactions, and the hydrophilic group forms hydrogen bonds with HIV-1 IN CCD residues from other subunit. CX14442 has a larger tert-butyl group than the methyl of BI-1001, and forms better interactions with the highly hydrophobic binding pocket of HIV-1 IN CCD dimer interface, which can explain the stronger affinity of CX14442 than BI-1001. Analysis of the binding mode of LEDGF/p75 with HIV-1 IN CCD reveals that the LEDGF/p75 integrase binding domain residues Ile365, Asp366, Phe406 and Val408 have significant contributions to the binding of the LEDGF/p75 to HIV1-IN. Remarkably, we found that binding of BI-1001 and CX14442 to HIV-1 IN CCD induced the structural rearrangements of the 140 s loop and oration displacements of the side chains of the three conserved catalytic residues Asp64, Asp116, and Glu152 located at the active site. These results we obtained will be valuable not only for understanding the allosteric inhibition mechanism of LEDGINs but also for the rational design of allosteric inhibitors of HIV-1 IN targeting LEDGF/p75 binding site.

Architecture and Assembly of HIV Integrase Multimers in the Absence of DNA Substrates*

Science.gov (United States)

Bojja, Ravi Shankar; Andrake, Mark D.; Merkel, George; Weigand, Steven; Dunbrack, Roland L.; Skalka, Anna Marie

2013-01-01

We have applied small angle x-ray scattering and protein cross-linking coupled with mass spectrometry to determine the architectures of full-length HIV integrase (IN) dimers in solution. By blocking interactions that stabilize either a core-core domain interface or N-terminal domain intermolecular contacts, we show that full-length HIV IN can form two dimer types. One is an expected dimer, characterized by interactions between two catalytic core domains. The other dimer is stabilized by interactions of the N-terminal domain of one monomer with the C-terminal domain and catalytic core domain of the second monomer as well as direct interactions between the two C-terminal domains. This organization is similar to the “reaching dimer” previously described for wild type ASV apoIN and resembles the inner, substrate binding dimer in the crystal structure of the PFV intasome. Results from our small angle x-ray scattering and modeling studies indicate that in the absence of its DNA substrate, the HIV IN tetramer assembles as two stacked reaching dimers that are stabilized by core-core interactions. These models of full-length HIV IN provide new insight into multimer assembly and suggest additional approaches for enzyme inhibition. PMID:23322775

Anatomo-pathological aspects of parasitism by nematodes of the superfamily Metastrongyloidea in wild crab-eating fox (Cerdocyon thous in Midwestern Brazil

Directory of Open Access Journals (Sweden)

Jair Alves Ferreira Júnior

Full Text Available ABSTRACT: Nematodes of the superfamily Metastrongyloidea affect the respiratory, cardiovascular, and nervous systems of domestic carnivores and are uncommonly detected in wild animals. This report describes the lesions associated with pulmonary parasitism by nematodes of the superfamily Metastrongyloidea in a wild crab-eating fox ( Cerdocyon thous in the Federal District, Brazil. Grossly, there was pulmonary hyperemia, edema, and emphysema. Microscopically, there was granulomatous arteritis associated with intravascular metastrongylid. The anatomical location, characteristic lesion, and histological features of the parasite suggested that the nematode involved in this case is Angiostrongylus vasorum . This worm is frequently reported parasitizing pulmonary arteries of domestic canids but is uncommonly described in wild canids in Midwestern Brazil.

Structural analysis of papain-like NlpC/P60 superfamily enzymes with a circularly permuted topology reveals potential lipid binding sites.

Directory of Open Access Journals (Sweden)

Qingping Xu

Full Text Available NlpC/P60 superfamily papain-like enzymes play important roles in all kingdoms of life. Two members of this superfamily, LRAT-like and YaeF/YiiX-like families, were predicted to contain a catalytic domain that is circularly permuted such that the catalytic cysteine is located near the C-terminus, instead of at the N-terminus. These permuted enzymes are widespread in virus, pathogenic bacteria, and eukaryotes. We determined the crystal structure of a member of the YaeF/YiiX-like family from Bacillus cereus in complex with lysine. The structure, which adopts a ligand-induced, "closed" conformation, confirms the circular permutation of catalytic residues. A comparative analysis of other related protein structures within the NlpC/P60 superfamily is presented. Permutated NlpC/P60 enzymes contain a similar conserved core and arrangement of catalytic residues, including a Cys/His-containing triad and an additional conserved tyrosine. More surprisingly, permuted enzymes have a hydrophobic S1 binding pocket that is distinct from previously characterized enzymes in the family, indicative of novel substrate specificity. Further analysis of a structural homolog, YiiX (PDB 2if6 identified a fatty acid in the conserved hydrophobic pocket, thus providing additional insights into possible function of these novel enzymes.

Evolution of Enzymatic Activities in the Enolase Superfamily: L-Fuconate Dehydratase from Xanthomonas campestris

Energy Technology Data Exchange (ETDEWEB)

Yew,W.; Fedorov, A.; Fedorov, E.; Rakus, J.; Pierce, R.; Almo, S.; Gerlt, J.

2006-01-01

Many members of the mechanistically diverse enolase superfamily have unknown functions. In this report the authors use both genome (operon) context and screening of a library of acid sugars to assign the L-fuconate dehydratase (FucD) function to a member of the mandelate racemase (MR) subgroup of the superfamily encoded by the Xanthomonas campestris pv. campestris str. ATCC 33913 genome (GI: 21233491). Orthologues of FucD are found in both bacteria and eukaryotes, the latter including the rTS beta protein in Homo sapiens that has been implicated in regulating thymidylate synthase activity. As suggested by sequence alignments and confirmed by high-resolution structures in the presence of active site ligands, FucD and MR share the same active site motif of functional groups: three carboxylate ligands for the essential Mg2+ located at the ends of th third, fourth, and fifth-strands in the (/)7-barrel domain (Asp 248, Glu 274, and Glu 301, respectively), a Lys-x-Lys motif at the end of the second-strand (Lys 218 and Lys 220), a His-Asp dyad at the end of the seventh and sixth-strands (His 351 and Asp 324, respectively), and a Glue at the end of the eighth-strand (Glu 382). The mechanism of the FucD reaction involves initial abstraction of the 2-proton by Lys 220, acid catalysis of the vinylogous-elimination of the 3-OH group by His 351, and stereospecific ketonization of the resulting 2-keto-3-deoxy-L-fuconate product. Screening of the library of acid sugars revealed substrate and functional promiscuity: In addition to L-fuconate, FucD also catalyzes the dehydration of L-galactonate, D-arabinonate, D-altronate, L-talonate, and D-ribonate. The dehydrations of L-fuconate, L-galactonate, and D-arabinonate are initiated by abstraction of the 2-protons by Lys 220. The dehydrations of L-talonate and D-ribonate are initiated by abstraction of the 2-protons by His 351; however, protonation of the enediolate intermediates by the conjugate acid of Lys 220 yields L

Retroviral DNA Integration Directed by HIV Integration Protein in Vitro

Science.gov (United States)

Bushman, Frederic D.; Fujiwara, Tamio; Craigie, Robert

1990-09-01

Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a λ DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.

Retroviral-mediated gene therapy for the differentiation of primary cells into a mineralizing osteoblastic phenotype.

Science.gov (United States)

Phillips, Jennifer E; García, Andrés J

2008-01-01

Bone tissue engineering has emerged as a promising strategy for the repair of critical-sized skeletal fractures. However, the clinical application of this approach has been limited by the availability of a robust mineralizing cell source. Non-osteogenic cells, such as skin fibroblasts, are an attractive cell-source alternative because they are easy to harvest from autologous donor skin biopsies and display a high capacity for in vitro expansion. We have recently demonstrated that retroviral gene delivery of the osteoblastic transcription factor Runx2/Cbfa1 promotes osteogenic differentiation in primary dermal fibroblasts cultured in monolayer. Notably, sustained expression of Runx2 was not sufficient to promote functional osteogenesis in these cells, and co-treatment with the steroid hormone dexamethasone was required to induce deposition of biologically-equivalent matrix mineralization. On the basis of these results, we then investigated the osteogenic capacity of these genetically engineered fibroblasts when seeded on polymeric scaffolds in vitro and in vivo. These experiments demonstrated that Runx2-expressing fibroblasts seeded on collagen scaffolds produce significant levels of matrix mineralization after 28 days in vivo implantation in a subcutaneous, heterotopic site. Overall, these results offer evidence that transcription factor-based gene therapy may be a powerful strategy for the conversion of a non-osteogenic cellular phenotype into a mineralizing cell source for bone repair applications. This concept may also be applied to control functional differentiation in a broad range of cell types and tissue engineering applications. The chapter below outlines detailed methods for the isolation and ex vivo genetic modification of primary dermal fibroblasts using retroviral-mediated delivery of the Runx2 transgene in both monolayer culture and three-dimensional scaffolds.

Two differentially regulated Arabidopsis genes define a new branch of the DFR superfamily

DEFF Research Database (Denmark)

Østergaard, L; Lauvergeat, V; Naested, H

2001-01-01

that, whereas high expression of AtCRL1 in mature seeds declines during subsequent vegetative growth, transcriptional activity from the AtCRL2 promoter increases during vegetative growth. Expression of both genes is restricted to vascular tissue. Based upon their homology to proteins involved in lignin......Two tandem genes were identified on Arabidopsis chromosome II (AtCRL1 and AtCRL2) encoding proteins with homology to members of the dihydroflavonol-4-reductase (DFR) superfamily. The encoded CRL1 and CRL2 proteins share 87% mutual amino acid sequence identity whereas their promoter regions...

O-linked glycosylation of retroviral envelope gene products

Energy Technology Data Exchange (ETDEWEB)

Pinter, A.; Honnen, W.J. (Public Health Research Institute of the City of New York Inc., NY (USA))

1988-03-01

Treatment of ({sup 3}H)glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M{sub r} (49K) product. For ({sup 3}H)mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90{sup env}, the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80{sup env}, and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins.

O-linked glycosylation of retroviral envelope gene products

International Nuclear Information System (INIS)

Pinter, A.; Honnen, W.J.

1988-01-01

Treatment of [ 3 H]glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M r (49K) product. For [ 3 H]mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90 env , the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80 env , and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins

Integrase-independent HIV-1 infection is augmented under conditions of DNA damage and produces a viral reservoir

International Nuclear Information System (INIS)

Ebina, Hirotaka; Kanemura, Yuka; Suzuki, Yasutsugu; Urata, Kozue; Misawa, Naoko; Koyanagi, Yoshio

2012-01-01

HIV-1 possesses a viral protein, integrase (IN), which is necessary for its efficient integration in target cells. However, it has been reported that an IN-defective HIV strain is still capable of integration. Here, we assessed the ability of wild type (WT) HIV-1 to establish infection in the presence of IN inhibitors. We observed a low, yet clear infection of inhibitor-incubated cells infected with WT HIV which was identical to cells infected with IN-deficient HIV, D64A. Furthermore, the IN-independent integration could be enhanced by the pretreatment of cells with DNA-damaging agents suggesting that integration is mediated by a DNA repair system. Moreover, significantly faster viral replication kinetics with augmented viral DNA integration was observed after infection in irradiated cells treated with IN inhibitor compared to nonirradiated cells. Altogether, our results suggest that HIV DNA has integration potential in the presence of an IN inhibitor and may serve as a virus reservoir.

Integrase-independent HIV-1 infection is augmented under conditions of DNA damage and produces a viral reservoir

Energy Technology Data Exchange (ETDEWEB)

Ebina, Hirotaka, E-mail: hebina@virus.kyoto-u.ac.jp; Kanemura, Yuka; Suzuki, Yasutsugu; Urata, Kozue; Misawa, Naoko; Koyanagi, Yoshio

2012-05-25

HIV-1 possesses a viral protein, integrase (IN), which is necessary for its efficient integration in target cells. However, it has been reported that an IN-defective HIV strain is still capable of integration. Here, we assessed the ability of wild type (WT) HIV-1 to establish infection in the presence of IN inhibitors. We observed a low, yet clear infection of inhibitor-incubated cells infected with WT HIV which was identical to cells infected with IN-deficient HIV, D64A. Furthermore, the IN-independent integration could be enhanced by the pretreatment of cells with DNA-damaging agents suggesting that integration is mediated by a DNA repair system. Moreover, significantly faster viral replication kinetics with augmented viral DNA integration was observed after infection in irradiated cells treated with IN inhibitor compared to nonirradiated cells. Altogether, our results suggest that HIV DNA has integration potential in the presence of an IN inhibitor and may serve as a virus reservoir.

Genetic polymorphisms of tumour necrosis factor receptor superfamily 1b and fas ligand are associated with clinical efficacy and/or acute severe infusion reactions to infliximab in Crohn's disease

DEFF Research Database (Denmark)

Steenholdt, C; Enevold, C; Ainsworth, M A

2012-01-01

Single nucleotide polymorphisms (SNPs) in TNF receptor superfamily (TNFRSF) 1A and 1B, and Fas ligand (FASLG) genes, have been associated with responsiveness to infliximab (IFX) in Crohn's disease.......Single nucleotide polymorphisms (SNPs) in TNF receptor superfamily (TNFRSF) 1A and 1B, and Fas ligand (FASLG) genes, have been associated with responsiveness to infliximab (IFX) in Crohn's disease....

The Anabaena sensory rhodopsin transducer defines a novel superfamily of prokaryotic small-molecule binding domains

Directory of Open Access Journals (Sweden)

De Souza Robson F

2009-08-01

Full Text Available Abstract The Anabaena sensory rhodopsin transducer (ASRT is a small protein that has been claimed to function as a signaling molecule downstream of the cyanobacterial sensory rhodopsin. However, orthologs of ASRT have been detected in several bacteria that lack rhodopsin, raising questions about the generality of this function. Using sequence profile searches we show that ASRT defines a novel superfamily of β-sandwich fold domains. Through contextual inference based on domain architectures and predicted operons and structural analysis we present strong evidence that these domains bind small molecules, most probably sugars. We propose that the intracellular versions like ASRT probably participate as sensors that regulate a diverse range of sugar metabolism operons or even the light sensory behavior in Anabaena by binding sugars or related metabolites. We also show that one of the extracellular versions define a predicted sugar-binding structure in a novel cell-surface lipoprotein found across actinobacteria, including several pathogens such as Tropheryma, Actinomyces and Thermobifida. The analysis of this superfamily also provides new data to investigate the evolution of carbohydrate binding modes in β-sandwich domains with very different topologies. Reviewers: This article was reviewed by M. Madan Babu and Mark A. Ragan.

Apoptosis Gene Hunting Using Retroviral Expression Cloning: Identification of Vacuolar ATPase Subunit E

Directory of Open Access Journals (Sweden)

Claire L. Anderson

2003-01-01

Full Text Available Over the past 10-15 years there has been an explosion of interest in apoptosis. The delayed realisation that cell death is an essential part of life for any multicellular organism has meant that, despite the recent and rapid developments of the last decade, the precise biochemical pathways involved in apoptosis remain incomplete and potentially novel genes may, as yet, remain undiscovered. The hunt is therefore on to bridge the remaining gaps in our knowledge. Our contribution to this research effort utilises a functional cloning approach to isolate important regulatory genes involved in apoptosis. This mini-review focuses on the use and advantages of a retroviral expression cloning strategy and describes the isolation and identification of one such potential apoptosis regulatory gene, namely that encoding vacuolar ATPase subunit E.

Crystal structure and potential physiological role of zebra fish thioesterase superfamily member 2 (fTHEM2)

Energy Technology Data Exchange (ETDEWEB)

Yu, Shanshan; Li, Han; Gao, Feng; Zhou, Ying, E-mail: zhouying@moon.ibp.ac.cn

2015-08-07

Thioesterase superfamily member 2 (THEM2) is an essential protein for mammalian cell proliferation. It belongs to the hotdog-fold thioesterase superfamily and catalyzes hydrolysis of thioester bonds of acyl-CoA in vitro, while its in vivo function remains unrevealed. In this study, Zebra fish was selected as a model organism to facilitate the investigations on THEM2. First, we solved the crystal structure of recombinant fTHEM2 at the resolution of 1.80 Å, which displayed a similar scaffolding as hTHEM2. Second, functional studies demonstrated that fTHEM2 is capable of hydrolyzing palmitoyl-CoA in vitro. In addition, injection of morpholino against fTHEM2 at one-cell stage resulted in distorted early embryo development, including delayed cell division, retarded development and increased death rate. The above findings validated our hypothesis that fTHEM2 could serve as an ideal surrogate for studying the physiological functions of THEM2. - Highlights: • The crystal structure of recombinant fTHEM2 is presented. • fTHEM2 is capable of hydrolyzing palmitoyl-CoA. • The influence of fTHEM2 on early embryo development is demonstrated.

Identification, immunolocalization, and characterization analyses of an exopeptidase of papain superfamily, (cathepsin C) from Clonorchis sinensis.

Science.gov (United States)

Liang, Pei; He, Lei; Xu, Yanquan; Chen, Xueqing; Huang, Yan; Ren, Mengyu; Liang, Chi; Li, Xuerong; Xu, Jin; Lu, Gang; Yu, Xinbing

2014-10-01

Cathepsin C is an important exopeptidase of papain superfamily and plays a number of great important roles during the parasitic life cycle. The amino acid sequence of cathepsin C from Clonorchis sinensis (C. sinensis) showed 54, 53, and 49% identities to that of Schistosoma japonicum, Schistosoma mansoni, and Homo sapiens, respectively. Phylogenetic analysis utilizing the sequences of papain superfamily of C. sinensis demonstrated that cathepsin C and cathepsin Bs came from a common ancestry. Cathepsin C of C. sinensis (Cscathepsin C) was identified as an excretory/secretory product by Western blot analysis. The results of transcriptional level and translational level of Cscathepsin C at metacercaria stage were higher than that at adult worms. Immunolocalization analysis indicated that Cscathepsin C was specifically distributed in the suckers (oral sucker and ventral sucker), eggs, vitellarium, intestines, and testis of adult worms. In the metacercaria, it was mainly detected on the cyst wall and excretory bladder. Combining with the results mentioned above, it implies that Cscathepsin C may be an essential proteolytic enzyme for proteins digestion of hosts, nutrition assimilation, and immune invasion of C. sinensis. Furthermore, it may be a potential diagnostic antigen and drug target against C. sinensis infection.

Retrovirally transduced NCAM140 facilitates neuronal fate choice of hippocampal progenitor cells.

Science.gov (United States)

Kim, Ju Hee; Lee, Jung-Ha; Park, Jin-Yong; Park, Chang-Hwan; Yun, Chae-Ok; Lee, Sang-Hun; Lee, Yong-Sung; Son, Hyeon

2005-07-01

Neural cell adhesion molecule (NCAM) influences proliferation and differentiation of neuronal cells. However, only a little is known about the downstream effects of NCAM signalling, such as alterations in gene transcription, which are associated with cell fate choice. To examine whether NCAM plays a role in cell fate choice during hippocampal neurogenesis, we performed a gain-of-function study, using a retroviral vector which contained full-length NCAM140 cDNA and the marker gene EGFP, and found that NCAM140 promoted neurogenesis by activating proneural transcription activators with concurrent inhibition of gliogenesis. The enhanced transcript levels of proneural transcription factors in NCAM140-transduced cells were down-regulated by treatment of the cells with mitogen-activated protein kinase kinase (MEK) inhibitor PD098059. Overall, these findings suggest that NCAM140 may facilitate hippocampal neurogenesis via regulation of proneurogenic transcription factors in an extracellular signal-regulated kinase (ERK)-dependent manner.

An effective HIV-1 integrase inhibitor screening platform: Rationality validation of drug screening, conformational mobility and molecular recognition analysis for PFV integrase complex with viral DNA.

Science.gov (United States)

Du, Wenyi; Zuo, Ke; Sun, Xin; Liu, Wei; Yan, Xiao; Liang, Li; Wan, Hua; Chen, Fengzheng; Hu, Jianping

2017-11-01

As an important target for the development of novel anti-AIDS drugs, HIV-1 integrase (IN) has been widely concerned. However, the lack of a complete accurate crystal structure of HIV-1 IN greatly blocks the discovery of novel inhibitors. In this work, an effective HIV-1 IN inhibitor screening platform, namely PFV IN, was filtered from all species of INs. Next, the 40.8% similarity with HIV-1 IN, as well as the high efficiency of virtual screening and the good agreement between calculated binding free energies and experimental ones all proved PFV IN is a promising screening platform for HIV-1 IN inhibitors. Then, the molecular recognition mechanism of PFV IN by its substrate viral DNA and six naphthyridine derivatives (NRDs) inhibitors was investigated through molecular docking, molecular dynamics simulations and water-mediated interactions analyses. The functional partition of NRDs IN inhibitors could be divided into hydrophobic and hydrophilic ones, and the Mg 2+ ions, water molecules and conserved DDE motif residues all interacted with the hydrophilic partition, while the bases in viral DNA and residues like Tyr212, Pro214 interacted with the hydrophobic one. Finally, the free energy landscape (FEL) and cluster analyses were performed to explore the molecular motion of PFV IN-DNA system. It is found that the association with NRDs inhibitors would obviously decrease the motion amplitude of PFV IN-DNA, which may be one of the most potential mechanisms of IN inhibitors. This work will provide a theoretical basis for the inhibitor design based on the structure of HIV-1 IN. Copyright © 2017 Elsevier Inc. All rights reserved.

Resistance Analyses of Integrase Strand Transfer Inhibitors within Phase 3 Clinical Trials of Treatment-Naive Patients

Directory of Open Access Journals (Sweden)

Kirsten L. White

2014-07-01

Full Text Available The integrase (IN strand transfer inhibitors (INSTIs, raltegravir (RAL, elvitegravir (EVG and dolutegravir (DTG, comprise the newest drug class approved for the treatment of HIV-1 infection, which joins the existing classes of reverse transcriptase, protease and binding/entry inhibitors. The efficacy of first-line regimens has attained remarkably high levels, reaching undetectable viral loads in 90% of patients by Week 48; however, there remain patients who require a change in regimen due to adverse events, virologic failure with emergent resistance or other issues of patient management. Large, randomized clinical trials conducted in antiretroviral treatment-naive individuals are required for drug approval in this population in the US, EU and other countries, with the primary endpoint for virologic success at Week 48. However, there are differences in the definition of virologic failure and the evaluation of drug resistance among the trials. This review focuses on the methodology and tabulation of resistance to INSTIs in phase 3 clinical trials of first-line regimens and discusses case studies of resistance.

Galatheoidea are not monophyletic - molecular and morphological phylogeny of the squat lobsters (Decapoda: Anomura) with recognition of a new superfamily.

Science.gov (United States)

Schnabel, K E; Ahyong, S T; Maas, E W

2011-02-01

The monophyletic status of the squat lobster superfamily Galatheoidea has come under increasing doubt by studies using evidence as diverse as larval and adult somatic morphology, sperm ultrastructure, and molecular data. Here we synthesize phylogenetic data from these diverse strands, with the addition of new molecular and morphological data to examine the phylogeny of the squat lobsters and assess the status of the Galatheoidea. A total of 64 species from 16 of the 17 currently recognised anomuran families are included. Results support previous work pointing towards polyphyly in the superfamily Galatheoidea and Paguroidea, specifically, suggesting independent origins of the Galatheidae+Porcellanidae and the Chirostylidae+Kiwaidae. Morphological characters are selected that support clades resolved in the combined analysis and the taxonomic status of Galatheoidea sensu lato is revised. Results indicate that Chirostylidae are more closely related to an assemblage including Aegloidea, Lomisoidea and Paguroidea than to the remaining Galatheoidea and are referred to the superfamily Chirostyloidea to include the Chirostylidae and Kiwaidae. A considerable amount of research highlighting morphological differences supporting this split is discussed. The Galatheoidea sensu stricto is restricted to the families Galatheidae and Porcellanidae, and diagnoses for both Chirostyloidea and Galatheoidea are provided. Present results highlight the need for a detailed revision of a number of taxa, challenge some currently used morphological synapomorphies, and emphasise the need for integrated studies with wide taxon sampling and multiple data sources to resolve complex phylogenetic questions. Copyright © 2010 Elsevier Inc. All rights reserved.

A histone-like protein of mycobacteria possesses ferritin superfamily protein-like activity and protects against DNA damage by Fenton reaction.

Directory of Open Access Journals (Sweden)

Masaki Takatsuka

Full Text Available Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe(2+ into Fe(3+ and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1, a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The K(m values of the ferroxidase activity by MDP1 of Mycobacterium bovis bacillus Calmette-Guérin (BCG-3007c, Mycobacterium tuberculosis (Rv2986c, and Mycobacterium leprae (ML1683; ML-LBP were 0.292, 0.252, and 0.129 mM, respectively. Furthermore, one MDP1 molecule directly captured 81.4±19.1 iron atoms, suggesting the role of this protein in iron storage. This study describes for the first time a ferroxidase-iron storage protein outside of the ferritin superfamily proteins and the protective role of this bacterial protein from DNA damage.

Identification of the S-transferase like superfamily bacillithiol transferases encoded by Bacillus subtilis

Science.gov (United States)

Perera, Varahenage R.; Lapek, John D.; Newton, Gerald L.; Gonzalez, David J.; Pogliano, Kit

2018-01-01

Bacillithiol is a low molecular weight thiol found in Firmicutes that is analogous to glutathione, which is absent in these bacteria. Bacillithiol transferases catalyze the transfer of bacillithiol to various substrates. The S-transferase-like (STL) superfamily contains over 30,000 putative members, including bacillithiol transferases. Proteins in this family are extremely divergent and are related by structural rather than sequence similarity, leaving it unclear if all share the same biochemical activity. Bacillus subtilis encodes eight predicted STL superfamily members, only one of which has been shown to be a bacillithiol transferase. Here we find that the seven remaining proteins show varying levels of metal dependent bacillithiol transferase activity. We have renamed the eight enzymes BstA-H. Mass spectrometry and gene expression studies revealed that all of the enzymes are produced to varying levels during growth and sporulation, with BstB and BstE being the most abundant and BstF and BstH being the least abundant. Interestingly, several bacillithiol transferases are induced in the mother cell during sporulation. A strain lacking all eight bacillithiol transferases showed normal growth in the presence of stressors that adversely affect growth of bacillithiol-deficient strains, such as paraquat and CdCl2. Thus, the STL bacillithiol transferases represent a new group of proteins that play currently unknown, but potentially significant roles in bacillithiol-dependent reactions. We conclude that these enzymes are highly divergent, perhaps to cope with an equally diverse array of endogenous or exogenous toxic metabolites and oxidants. PMID:29451913

Pulmonary artery hypertension in childhood: The transforming growth factor-β superfamily-related genes

Directory of Open Access Journals (Sweden)

Shi-Min Yuan

2018-04-01

Full Text Available Pulmonary artery hypertension (PAH is very rare in childhood, and it can be divided into heritable, idiopathic drug- and toxin-induced and other disease (connective tissue disease, human immunodeficiency virus infection, portal hypertension, congenital heart disease, or schistosomiasis-associated types. PAH could not be interpreted solely by pathophysiological theories. The impact of the transforming growth factor-β superfamily-related genes on the development of PAH in children remains to be clarified. Pertinent literature on the transforming growth factor-β superfamily-related genes in relation to PAH in children published after the year 2000 was reviewed and analyzed. Bone morphogenetic protein receptor type II gene mutation promotes cell division or prevents cell death, resulting in an overgrowth of cells in small arteries throughout the lungs. About 20% of individuals with a bone morphogenetic protein receptor type II gene mutation develop symptomatic PAH. In heritable PAH, bone morphogenetic protein receptor type II mutations may be absent; while mutations of other genes, such as type I receptor activin receptor-like kinase 1 and the type III receptor endoglin (both associated with hereditary hemorrhagic telangiectasia, caveolin-1 and KCNK3, the gene encoding potassium channel subfamily K, member 3, can be detected, instead. Gene mutations, environmental changes and acquired adjustment, etc. may explain the development of PAH. The researches on PAH rat model and familial PAH members may facilitate the elucidations of the mechanisms and further provide theories for prophylaxis and treatment of PAH. Key Words: bone morphogenetic proteins, mutation, pulmonary hypertension

Regulation of human heme oxygenase in endothelial cells by using sense and antisense retroviral constructs.

Science.gov (United States)

Quan, S; Yang, L; Abraham, N G; Kappas, A

2001-10-09

Our objective was to determine whether overexpression and underexpression of human heme oxygenase (HHO)-1 could be controlled on a long-term basis by introduction of the HO-1 gene in sense (S) and antisense (AS) orientation with an appropriate vector into endothelial cells. Retroviral vector (LXSN) containing viral long terminal repeat promoter-driven human HO-1 S (LSN-HHO-1) and LXSN vectors containing HHO-1 promoter (HOP)-controlled HHO-1 S and AS (LSN-HOP-HHO-1 and LSN-HOP-HHO-1-AS) sequences were constructed and used to transfect rat lung microvessel endothelial cells (RLMV cells) and human dermal microvessel endothelial cells (HMEC-1 cells). RLMV cells transduced with HHO-1 S expressed human HO-1 mRNA and HO-1 protein associated with elevation in total HO activity compared with nontransduced cells. Vector-mediated expression of HHO-1 S or AS under control of HOP resulted in effective production of HO-1 or blocked induction of endogenous human HO-1 in HMEC-1 cells, respectively. Overexpression of HO-1 AS was associated with a long-term decrease (45%) of endogenous HO-1 protein and an increase (167%) in unmetabolized exogenous heme in HMEC-1 cells. Carbon monoxide (CO) production in HO-1 S- or AS-transduced HMEC-1 cells after heme treatment was increased (159%) or decreased (50%), respectively, compared with nontransduced cells. HO-2 protein levels did not change. These findings demonstrate that HHO-1 S and AS retroviral constructs are functional in enhancing and reducing HO activity, respectively, and thus can be used to regulate cellular heme levels, the activity of heme-dependent enzymes, and the rate of heme catabolism to CO and bilirubin.

RASOnD - A comprehensive resource and search tool for RAS superfamily oncogenes from various species

Directory of Open Access Journals (Sweden)

Singh Tej P

2011-07-01

Full Text Available Abstract Background The Ras superfamily plays an important role in the control of cell signalling and division. Mutations in the Ras genes convert them into active oncogenes. The Ras oncogenes form a major thrust of global cancer research as they are involved in the development and progression of tumors. This has resulted in the exponential growth of data on Ras superfamily across different public databases and in literature. However, no dedicated public resource is currently available for data mining and analysis on this family. The present database was developed to facilitate straightforward accession, retrieval and analysis of information available on Ras oncogenes from one particular site. Description We have developed the RAS Oncogene Database (RASOnD as a comprehensive knowledgebase that provides integrated and curated information on a single platform for oncogenes of Ras superfamily. RASOnD encompasses exhaustive genomics and proteomics data existing across diverse publicly accessible databases. This resource presently includes overall 199,046 entries from 101 different species. It provides a search tool to generate information about their nucleotide and amino acid sequences, single nucleotide polymorphisms, chromosome positions, orthologies, motifs, structures, related pathways and associated diseases. We have implemented a number of user-friendly search interfaces and sequence analysis tools. At present the user can (i browse the data (ii search any field through a simple or advance search interface and (iii perform a BLAST search and subsequently CLUSTALW multiple sequence alignment by selecting sequences of Ras oncogenes. The Generic gene browser, GBrowse, JMOL for structural visualization and TREEVIEW for phylograms have been integrated for clear perception of retrieved data. External links to related databases have been included in RASOnD. Conclusions This database is a resource and search tool dedicated to Ras oncogenes. It has

The RNA binding G-patch domain in retroviral protease is important for infectivity and D-type morphogenesis of Mason-Pfizer monkey virus

Czech Academy of Sciences Publication Activity Database

Bauerová, Helena; Štokrová, Jitka; Stříšovský, Kvido; Hunter, E.; Ruml, Tomáš; Pichová, Iva

2005-01-01

Roč. 280, č. 51 (2005), s. 42106-42112 ISSN 0021-9258 R&D Projects: GA MŠk(CZ) 1M0508; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : retroviral protease * RNA binding domain * M-PMV * infectivity * assembly Subject RIV: CE - Biochemistry Impact factor: 5.854, year: 2005

Retroviral infection of non-dividing cells: Old and new perspectives

International Nuclear Information System (INIS)

Yamashita, Masahiro; Emerman, Michael

2006-01-01

The dependence of retroviral replication on cell proliferation was described as early as 1958, although different classes of retroviruses are able to infect non-dividing cells with different efficiencies. For example, the human immunodeficiency virus (HIV) and other lentiviruses infect most non-dividing cells nearly as well as dividing cells, while the gammaretroviruses such as the murine leukemia virus (MLV) cannot infect non-dividing cells, and other retroviruses have intermediate phenotypes. One exception to the ability of HIV to infect non-dividing cells involves resting CD4+ T cells in vitro where there are multiple restrictions. However, recent data show that there is massive infection of non-activated CD4+ T cell during acute infection which suggests that the situation is different in vivo. Finally, much work trying to explain the difference between HIV and MLV in non-dividing cells has focused on describing the ability of HIV to enter the nucleus during interphase. However, we suggest that events in the viral lifecycle other than nuclear import may be more important in determining the ability of a given retrovirus to infect non-dividing cells

Removal of bacterial cells, antibiotic resistance genes and integrase genes by on-site hospital wastewater treatment plants: surveillance of treated hospital effluent quality

KAUST Repository

Timraz, Kenda Hussain Hassan

2016-12-15

This study aims to evaluate the removal efficiency of microbial contaminants, including total cell counts, antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs, e.g. tetO, tetZ, sul1 and sul2) and integrase genes (e.g. intl1 and intl2), by wastewater treatment plants (WWTPs) operated on-site of two hospitals (i.e., SH WWTP and IH WWTP). Both SH and IH WWTPs utilize the conventional activated sludge process but differences in the removal efficiencies were observed. Over the 2 week sampling period, IH WWTP outperformed SH WWTP, and achieved an approximate 0.388 to 2.49-log log removal values (LRVs) for total cell counts compared to the 0.010 to 0.162-log removal in SH WWTP. Although ARB were present in the hospital influent, the treatment process of both hospitals effectively removed ARB from most of the effluent samples. In instances where ARB were recovered in the effluent, none of the viable isolates were identified to be opportunistic pathogenic species based on 16S rRNA gene sequencing. However, sul1 and intl1 genes remained detectable at up to 105 copies per mL or 8 x 10(-1) copies per 16S rRNA gene in the treated effluent, with an LRV of less than 1.2. When the treated effluent is discharged from hospital WWTPs into the public sewer for further treatment as per requirement in many countries, the detected amount of ARGs and integrase genes in the hospital effluent can become a potential source of horizontal gene dissemination in the municipal WWTP. Proper on-site wastewater treatment and surveillance of the effluent quality for emerging contaminants are therefore highly recommended.

Retroviral DNA integration: viral and cellular determinants of target-site selection.

Directory of Open Access Journals (Sweden)

Mary K Lewinski

2006-06-01

Full Text Available Retroviruses differ in their preferences for sites for viral DNA integration in the chromosomes of infected cells. Human immunodeficiency virus (HIV integrates preferentially within active transcription units, whereas murine leukemia virus (MLV integrates preferentially near transcription start sites and CpG islands. We investigated the viral determinants of integration-site selection using HIV chimeras with MLV genes substituted for their HIV counterparts. We found that transferring the MLV integrase (IN coding region into HIV (to make HIVmIN caused the hybrid to integrate with a specificity close to that of MLV. Addition of MLV gag (to make HIVmGagmIN further increased the similarity of target-site selection to that of MLV. A chimeric virus with MLV Gag only (HIVmGag displayed targeting preferences different from that of both HIV and MLV, further implicating Gag proteins in targeting as well as IN. We also report a genome-wide analysis indicating that MLV, but not HIV, favors integration near DNase I-hypersensitive sites (i.e., +/- 1 kb, and that HIVmIN and HIVmGagmIN also favored integration near these features. These findings reveal that IN is the principal viral determinant of integration specificity; they also reveal a new role for Gag-derived proteins, and strengthen models for integration targeting based on tethering of viral IN proteins to host proteins.

Fetal antigen 1 (FA1), a circulating member of the epidermal growth factor (EGF) superfamily

DEFF Research Database (Denmark)

Jensen, Charlotte Harken; Krogh, T N; Støving, René Klinkby

1997-01-01

We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3.2% and an aver......We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3.......2% and an average recovery of 105% in serum and 98% in urine. Comparison of FA1 in amniotic fluid, serum and urine revealed parallel titration curves, identical elution volumes following size chromatography, immunological identity and similar profiles when analysed by MALDI-MS. The reference interval for serum FA1...... was 12.3-46.6 ng/ml and the levels were 10 times higher in patients with renal failure. FA1 showed no diurnal variation, no variation during the menstrual cycle and was not influenced by the acute phase reaction. In humans (n = 10) the renal clearance of FA1 was 11 ml/min and an identical high renal...

Classification of Rhizomonas suberifaciens, an unnamed Rhizomonas species, and Sphingomonas spp. in rRNA superfamily IV.

Science.gov (United States)

van Bruggen, A H; Jochimsen, K N; Steinberger, E M; Segers, P; Gillis, M

1993-01-01

Thermal melting profiles of hybrids between 3H-labeled rRNA of Rhizomonas suberifaciens, the causal agent of corky root of lettuce, and chromosomal DNAs from 27 species of gram-negative bacteria indicated that the genus Rhizomonas belongs to superfamily IV of De Ley. On the basis of the melting temperatures of DNA hybrids with rRNAs from the type strains of R. suberifaciens, Sphingomonas paucimobilis, and Sphingomonas capsulata, Rhizomonas strains constitute a separate branch in superfamily IV, which is closely related to but separate from branches containing Zymomonas mobilis, Sphingomonas spp., and S. capsulata. Sphingomonas yanoikuyae and Rhizomonas sp. strain WI4 are located toward the base of the Rhizomonas rRNA branch. DNA-DNA hybridization indicated that S. yanoikuyae is equidistant from Rhizomonas sp. strain WI4 and S. paucimobilis. Sequences of 270 bp of 16S ribosomal DNAs from eight strains of Rhizomonas spp., eight strains of Sphingomonas spp., and Agrobacterium tumefaciens indicated that S. yanoikuyae and Rhizomonas sp. strains WI4 and CA16 are genetically more closely related to R. suberifaciens than to Sphingomonas spp. Thus, S. yanoikuyae may need to be transferred to the genus Rhizomonas on the basis of the results of further study.

Intracellular Transport and Kinesin Superfamily Proteins: Structure, Function and Dynamics

Science.gov (United States)

Hirokawa, N.; Takemura, R.

Using various molecular cell biological and molecular genetic approaches, we identified kinesin superfamily proteins (KIFs) and characterized their significant functions in intracellular transport, which is fundamental for cellular morphogenesis, functioning, and survival. We showed that KIFs not only transport various membranous organelles, proteins complexes and mRNAs fundamental for cellular functions but also play significant roles in higher brain functions such as memory and learning, determination of important developmental processes such as left-right asymmetry formation and brain wiring. We also elucidated that KIFs recognize and bind to their specific cargoes using scaffolding or adaptor protein complexes. Concerning the mechanism of motility, we discovered the simplest unique monomeric motor KIF1A and determined by molecular biophysics, cryoelectron microscopy and X-ray crystallography that KIF1A can move on a microtubule processively as a monomer by biased Brownian motion and by hydolyzing ATP.

Cell Adhesion Molecules of the Immunoglobulin Superfamily in the Nervous System

DEFF Research Database (Denmark)

Walmod, Peter Schledermann; Pedersen, Martin Volmer; Berezin, Vladimir

2007-01-01

Cell adhesion molecules (CAMs) are proteins mediating cell-cell or cell-extracellular matrix (ECM) interactions. CAMs are traditionally divided into four groups, the cadherins, the selectins, the integrins and CAMs belonging to the immunoglobulin superfamily (IgSF). The present chapter describes...... CAMs belonging to IgSF, that exclusively or in part, are expressed in the nervous system. The chapter includes descriptions of myelin protein zero (P0), integrin-associated protein (CD47), neuroplastin, activated leukocyte-cell adhesion molecule (ALCAM), melanoma cell adhesion molecule (MCAM......), myelinassociated glycoprotein (MAG), the neural cell adhesion molecules 1 and 2 (NCAM, NCAM2), Down Syndrome cell adhesion molecule (DSCAM) and Down Syndrome cell adhesion molecule-like-1 (DSCAML1), sidekick 1 and 2 (SDK1, SDK2), signal-regulatory proteins (SIRPs), nectins, nectin-like proteins (necls...

Five Drosophila Genomes Reveal Nonneutral Evolution and the Signature of Host Specialization in the Chemoreceptor Superfamily

OpenAIRE

McBride, Carolyn S.; Arguello, J. Roman

2007-01-01

The insect chemoreceptor superfamily comprises the olfactory receptor (Or) and gustatory receptor (Gr) multigene families. These families give insects the ability to smell and taste chemicals in the environment and are thus rich resources for linking molecular evolutionary and ecological processes. Although dramatic differences in family size among distant species and high divergence among paralogs have led to the belief that the two families evolve rapidly, a lack of evolutionary data over s...

D-Ribulose 5-Phosphate 3-Epimerase: Functional and Structural Relationships to Members of the Ribulose-Phosphate Binding (beta/alpha)8-Barrel Superfamily

International Nuclear Information System (INIS)

Akana, J.; Federov, A.; Federov, E.; Novak, W.; Babbitt, P.; Almo, S.; Gerlt, J.

2006-01-01

The 'ribulose phosphate binding' superfamily defined by the Structural Classification of Proteins (SCOP) database is considered the result of divergent evolution from a common (β/α) 8 -barrel ancestor. The superfamily includes D-ribulose 5-phosphate 3-epimerase (RPE), orotidine 5'-monophosphate decarboxylase (OMPDC), and 3-keto-L-gulonate 6-phosphate decarboxylase (KGPDC), members of the OMPDC suprafamily, as well as enzymes involved in histidine and tryptophan biosynthesis that utilize phosphorylated metabolites as substrates. We now report studies of the functional and structural relationships of RPE to the members of the superfamily. As suggested by the results of crystallographic studies of the RPEs from rice and Plasmodium falciparum, the RPE from Streptococcus pyogenes is activated by Zn 2+ which binds with a stoichiometry of one ion per polypeptide. Although wild type RPE has a high affinity for Zn 2+ and inactive apoenzyme cannot be prepared, the affinity for Zn 2+ is decreased by alanine substitutions for the two histidine residues that coordinate the Zn 2+ ion (H34A and H67A); these mutant proteins can be prepared in an inactive, metal-free form and activated by exogenous Zn 2+ . The crystal structure of the RPE was solved at 1.8 Angstroms resolution in the presence of D-xylitol 5-phosphate, an inert analogue of the D-xylulose 5-phosphate substrate. This structure suggests that the 2,3-enediolate intermediate in the 1,1-proton transfer reaction is stabilized by bidentate coordination to the Zn 2+ that also is liganded to His 34, Asp 36, His 67, and Asp 176; the carboxylate groups of the Asp residues are positioned also to function as the acid/base catalysts. Although the conformation of the bound analogue resembles those of ligands bound in the active sites of OMPDC and KGPDC, the identities of the active site residues that coordinate the essential Zn 2+ and participate as acid/base catalysts are not conserved. We conclude that only the phosphate

D-Ribulose 5-Phosphate 3-Epimerase: Functional and Structural Relationships to Members of the Ribulose-Phosphate Binding (beta/alpha)8-Barrel Superfamily

Energy Technology Data Exchange (ETDEWEB)

Akana,J.; Federov, A.; Federov, E.; Novak, W.; Babbitt, P.; Almo, S.; Gerlt, J.

2006-01-01

The 'ribulose phosphate binding' superfamily defined by the Structural Classification of Proteins (SCOP) database is considered the result of divergent evolution from a common ({beta}/{alpha}){sub 8}-barrel ancestor. The superfamily includes D-ribulose 5-phosphate 3-epimerase (RPE), orotidine 5'-monophosphate decarboxylase (OMPDC), and 3-keto-L-gulonate 6-phosphate decarboxylase (KGPDC), members of the OMPDC suprafamily, as well as enzymes involved in histidine and tryptophan biosynthesis that utilize phosphorylated metabolites as substrates. We now report studies of the functional and structural relationships of RPE to the members of the superfamily. As suggested by the results of crystallographic studies of the RPEs from rice and Plasmodium falciparum, the RPE from Streptococcus pyogenes is activated by Zn{sup 2+} which binds with a stoichiometry of one ion per polypeptide. Although wild type RPE has a high affinity for Zn{sup 2+} and inactive apoenzyme cannot be prepared, the affinity for Zn{sup 2+} is decreased by alanine substitutions for the two histidine residues that coordinate the Zn{sup 2+} ion (H34A and H67A); these mutant proteins can be prepared in an inactive, metal-free form and activated by exogenous Zn{sup 2+}. The crystal structure of the RPE was solved at 1.8 Angstroms resolution in the presence of D-xylitol 5-phosphate, an inert analogue of the D-xylulose 5-phosphate substrate. This structure suggests that the 2,3-enediolate intermediate in the 1,1-proton transfer reaction is stabilized by bidentate coordination to the Zn{sup 2+} that also is liganded to His 34, Asp 36, His 67, and Asp 176; the carboxylate groups of the Asp residues are positioned also to function as the acid/base catalysts. Although the conformation of the bound analogue resembles those of ligands bound in the active sites of OMPDC and KGPDC, the identities of the active site residues that coordinate the essential Zn{sup 2+} and participate as acid/base catalysts

A revised nomenclature for transcribed human endogenous retroviral loci

Science.gov (United States)

2011-01-01

Background Endogenous retroviruses (ERVs) and ERV-like sequences comprise 8% of the human genome. A hitherto unknown proportion of ERV loci are transcribed and thus contribute to the human transcriptome. A small proportion of these loci encode functional proteins. As the role of ERVs in normal and diseased biological processes is not yet established, transcribed ERV loci are of particular interest. As more transcribed ERV loci are likely to be identified in the near future, the development of a systematic nomenclature is important to ensure that all information on each locus can be easily retrieved. Results Here we present a revised nomenclature of transcribed human endogenous retroviral loci that sorts loci into groups based on Repbase classifications. Each symbol is of the format ERV + group symbol + unique number. Group symbols are based on a mixture of Repbase designations and well-supported symbols used in the literature. The presented guidelines will allow newly identified loci to be easily incorporated into the scheme. Conclusions The naming system will be employed by the HUGO Gene Nomenclature Committee for naming transcribed human ERV loci. We hope that the system will contribute to clarifying a certain aspect of a sometimes confusing nomenclature for human endogenous retroviruses. The presented system may also be employed for naming transcribed loci of human non-ERV repeat loci. PMID:21542922

Study on constructing retroviral vector carrying HSV-tk gene and its antitumor effect in vitro

International Nuclear Information System (INIS)

Pan Yujun; Hui Guozhen; Hu Jin

1997-01-01

The author reports the construction of retroviral vector PLNTK carrying HsV-tk gene driven by pgk promoter and the successful transferring into cells NBA 2 and SHG 44 respectively as shown by PCR. In vitro study, HSV-tk-expressed-cells prove to be more sensitive to ACV than parent cells. The sensitivity of SHGLNTK and NBALNTK to ACV is 1000 and 500 times that of their parent cells respectively. 3 H-TdR test demonstrated that the DNA replication in gene modified cells is more suppressed than that of parent cells when treated with ACV. Moreover, the ACV sensitivity level of parent cells is enhanced when co-cultured with gene modified cells, which suggests the existence of the bystander effect

Inclusion of Moloney murine leukemia virus elements upstream of the transgene cassette in an E1-deleted adenovirus leads to an unusual genomic integration in epithelial cells

International Nuclear Information System (INIS)

Zheng Changyu; O'Connell, Brian C.; Baum, Bruce J.

2003-01-01

Classically, the 5' and 3' long terminal repeats (LTRs) are considered necessary but not sufficient for retroviral integration. Recently, we reported that inclusion of these and additional elements from Moloney murine leukemia virus (MoMLV) facilitated transgene integration, without retroviral integrase, when placed in an adenoviral context (AdLTR-luc vector) (Nat. Biotech. 18 (2000), 176; Biochem. Biophys. Res. Commun. 300 (2003), 115). To help understand this nonhomologous DNA recombination event, we constructed another vector, AdELP-luc, with 2.7 kb of MoMLV elements identically placed into an E1-deleted adenovirus type 5 backbone upstream of a luciferase cDNA reporter gene. Unlike AdLTR-luc, no MoMLV elements were placed downstream of the expression cassette. AdELP-luc readily infected epithelial cells in vitro. Southern hybridizations with DNA from cloned cells showed that disruption of the MoMLV sequences occurred. One cell clone, grown in vitro without any special selection medium for 9 months, exhibited stable vector integration and luciferase activity. Importantly, both Southern hybridization and FISH analyses showed that in addition to the MoMLV elements and expression cassette, substantial adenoviral sequence downstream of the luciferase cDNA was genomically integrated. These results suggest that the 2.7 kb of MoMLV sequence included in AdELP-luc have cis-acting functions and mediates an unusual integration event

Molecular cloning of a peroxisomal Ca2+-dependent member of the mitochondrial carrier superfamily

Science.gov (United States)

Weber, Franz E.; Minestrini, Gianluca; Dyer, James H.; Werder, Moritz; Boffelli, Dario; Compassi, Sabina; Wehrli, Ernst; Thomas, Richard M.; Schulthess, Georg; Hauser, Helmut

1997-01-01

A cDNA from a novel Ca2+-dependent member of the mitochondrial solute carrier superfamily was isolated from a rabbit small intestinal cDNA library. The full-length cDNA clone was 3,298 nt long and coded for a protein of 475 amino acids, with four elongation factor-hand motifs located in the N-terminal half of the molecule. The 25-kDa N-terminal polypeptide was expressed in Escherichia coli, and it was demonstrated that it bound Ca2+, undergoing a reversible and specific conformational change as a result. The conformation of the polypeptide was sensitive to Ca2+ which was bound with high affinity (Kd ≈ 0.37 μM), the apparent Hill coefficient for Ca2+-induced changes being about 2.0. The deduced amino acid sequence of the C-terminal half of the molecule revealed 78% homology to Grave disease carrier protein and 67% homology to human ADP/ATP translocase; this sequence homology identified the protein as a new member of the mitochondrial transporter superfamily. Northern blot analysis revealed the presence of a single transcript of about 3,500 bases, and low expression of the transporter could be detected in the kidney but none in the liver. The main site of expression was the colon with smaller amounts found in the small intestine proximal to the ileum. Immunoelectron microscopy localized the transporter in the peroxisome, although a minor fraction was found in the mitochondria. The Ca2+ binding N-terminal half of the transporter faces the cytosol. PMID:9238007

The TULIP superfamily of eukaryotic lipid-binding proteins as a mediator of lipid sensing and transport.

Science.gov (United States)

Alva, Vikram; Lupas, Andrei N

2016-08-01

The tubular lipid-binding (TULIP) superfamily has emerged in recent years as a major mediator of lipid sensing and transport in eukaryotes. It currently encompasses three protein families, SMP-like, BPI-like, and Takeout-like, which share a common fold. This fold consists of a long helix wrapped in a highly curved anti-parallel β-sheet, enclosing a central, lipophilic cavity. The SMP-like proteins, which include subunits of the ERMES complex and the extended synaptotagmins (E-Syts), appear to be mainly located at membrane contacts sites (MCSs) between organelles, mediating inter-organelle lipid exchange. The BPI-like proteins, which include the bactericidal/permeability-increasing protein (BPI), the LPS (lipopolysaccharide)-binding protein (LBP), the cholesteryl ester transfer protein (CETP), and the phospholipid transfer protein (PLTP), are either involved in innate immunity against bacteria through their ability to sense lipopolysaccharides, as is the case for BPI and LBP, or in lipid exchange between lipoprotein particles, as is the case for CETP and PLTP. The Takeout-like proteins, which are comprised of insect juvenile hormone-binding proteins and arthropod allergens, transport, where known, lipid hormones to target tissues during insect development. In all cases, the activity of these proteins is underpinned by their ability to bind large, hydrophobic ligands in their central cavity and segregate them away from the aqueous environment. Furthermore, where they are involved in lipid exchange, recent structural studies have highlighted their ability to establish lipophilic, tubular channels, either between organelles in the case of SMP domains or between lipoprotein particles in the case of CETP. Here, we review the current knowledge on the structure, versatile functions, and evolution of the TULIP superfamily. We propose a deep evolutionary split in this superfamily, predating the Last Eukaryotic Common Ancestor, between the SMP-like proteins, which act on

Retroviral insertional mutagenesis identifies Zeb2 activation as a novel leukemogenic collaborating event in CALM-AF10 transgenic mice.

Science.gov (United States)

Caudell, David; Harper, David P; Novak, Rachel L; Pierce, Rachel M; Slape, Christopher; Wolff, Linda; Aplan, Peter D

2010-02-11

The t(10;11) translocation results in a CALM-AF10 fusion gene in a subset of leukemia patients. Expression of a CALM-AF10 transgene results in leukemia, with prolonged latency and incomplete penetrance, suggesting that additional events are necessary for leukemic transformation. CALM-AF10 mice infected with the MOL4070LTR retrovirus developed acute leukemia, and ligation-mediated polymerase chain reaction was used to identify retroviral insertions at 19 common insertion sites, including Zeb2, Nf1, Mn1, Evi1, Ift57, Mpl, Plag1, Kras, Erg, Vav1, and Gata1. A total of 26% (11 of 42) of the mice had retroviral integrations near Zeb2, a transcriptional corepressor leading to overexpression of the Zeb2-transcript. A total of 91% (10 of 11) of mice with Zeb2 insertions developed B-lineage acute lymphoblastic leukemia, suggesting that Zeb2 activation promotes the transformation of CALM-AF10 hematopoietic precursors toward B-lineage leukemias. More than half of the mice with Zeb2 integrations also had Nf1 integrations, suggesting cooperativity among CALM-AF10, Zeb2, and Ras pathway mutations. We searched for Nras, Kras, and Ptpn11 point mutations in the CALM-AF10 leukemic mice. Three mutations were identified, all of which occurred in mice with Zeb2 integrations, consistent with the hypothesis that Zeb2 and Ras pathway activation promotes B-lineage leukemic transformation in concert with CALM-AF10.

Comprehensive profiling of retroviral integration sites using target enrichment methods from historical koala samples without an assembled reference genome

Directory of Open Access Journals (Sweden)

Pin Cui

2016-03-01

Full Text Available Background. Retroviral integration into the host germline results in permanent viral colonization of vertebrate genomes. The koala retrovirus (KoRV is currently invading the germline of the koala (Phascolarctos cinereus and provides a unique opportunity for studying retroviral endogenization. Previous analysis of KoRV integration patterns in modern koalas demonstrate that they share integration sites primarily if they are related, indicating that the process is currently driven by vertical transmission rather than infection. However, due to methodological challenges, KoRV integrations have not been comprehensively characterized. Results. To overcome these challenges, we applied and compared three target enrichment techniques coupled with next generation sequencing (NGS and a newly customized sequence-clustering based computational pipeline to determine the integration sites for 10 museum Queensland and New South Wales (NSW koala samples collected between the 1870s and late 1980s. A secondary aim of this study sought to identify common integration sites across modern and historical specimens by comparing our dataset to previously published studies. Several million sequences were processed, and the KoRV integration sites in each koala were characterized. Conclusions. Although the three enrichment methods each exhibited bias in integration site retrieval, a combination of two methods, Primer Extension Capture and hybridization capture is recommended for future studies on historical samples. Moreover, identification of integration sites shows that the proportion of integration sites shared between any two koalas is quite small.

Analysis of proviral integration in human mammary epithelial cell lines immortalized by retroviral infection with a temperature-sensitive SV40 T-antigen construct.

Science.gov (United States)

Stamps, A C; Davies, S C; Burman, J; O'Hare, M J

1994-06-15

A panel of eight conditionally immortal lines derived by infection of human breast epithelial cells with an amphotropic retrovirus transducing a ts mutant of SV40 large T-antigen was analyzed with respect to individual retroviral integration patterns. Each line contained multiple integration sites which were clonal and stable over extended passage. Similar integration patterns were observed between individual lines arising separately from the same stock of pre-immortal cells, suggesting a common progenitor. Retroviral integration analysis of pre-immortal cells at different stages of pre-crisis growth showed changes indicative of a progressive transition from polyclonality to clonality as the cells approached crisis. Each of the immortal lines contained a sub-set of the integration sites of their pre-immortal progenitors, with individual combinations and copy numbers of sites. Since all the cell lines appeared to originate from single foci in separate flasks, it is likely that each set arose from a common clone of pre-immortal cells as the result of separate genetic events. There was no evidence from this analysis to suggest that specific integration sites played any part either in the selection of pre-crisis clones or in the subsequent establishment of immortal lines.

Homology models guide discovery of diverse enzyme specificities among dipeptide epimerases in the enolase superfamily

Science.gov (United States)

Lukk, Tiit; Sakai, Ayano; Kalyanaraman, Chakrapani; Brown, Shoshana D.; Imker, Heidi J.; Song, Ling; Fedorov, Alexander A.; Fedorov, Elena V.; Toro, Rafael; Hillerich, Brandan; Seidel, Ronald; Patskovsky, Yury; Vetting, Matthew W.; Nair, Satish K.; Babbitt, Patricia C.; Almo, Steven C.; Gerlt, John A.; Jacobson, Matthew P.

2012-01-01

The rapid advance in genome sequencing presents substantial challenges for protein functional assignment, with half or more of new protein sequences inferred from these genomes having uncertain assignments. The assignment of enzyme function in functionally diverse superfamilies represents a particular challenge, which we address through a combination of computational predictions, enzymology, and structural biology. Here we describe the results of a focused investigation of a group of enzymes in the enolase superfamily that are involved in epimerizing dipeptides. The first members of this group to be functionally characterized were Ala-Glu epimerases in Eschericiha coli and Bacillus subtilis, based on the operon context and enzymological studies; these enzymes are presumed to be involved in peptidoglycan recycling. We have subsequently studied more than 65 related enzymes by computational methods, including homology modeling and metabolite docking, which suggested that many would have divergent specificities;, i.e., they are likely to have different (unknown) biological roles. In addition to the Ala-Phe epimerase specificity reported previously, we describe the prediction and experimental verification of: (i) a new group of presumed Ala-Glu epimerases; (ii) several enzymes with specificity for hydrophobic dipeptides, including one from Cytophaga hutchinsonii that epimerizes D-Ala-D-Ala; and (iii) a small group of enzymes that epimerize cationic dipeptides. Crystal structures for certain of these enzymes further elucidate the structural basis of the specificities. The results highlight the potential of computational methods to guide experimental characterization of enzymes in an automated, large-scale fashion. PMID:22392983

TED, an autonomous and rare maize transposon of the mutator superfamily with a high gametophytic excision frequency.

Science.gov (United States)

Li, Yubin; Harris, Linda; Dooner, Hugo K

2013-09-01

Mutator (Mu) elements, one of the most diverse superfamilies of DNA transposons, are found in all eukaryotic kingdoms, but are particularly numerous in plants. Most of the present knowledge on the transposition behavior of this superfamily comes from studies of the maize (Zea mays) Mu elements, whose transposition is mediated by the autonomous Mutator-Don Robertson (MuDR) element. Here, we describe the maize element TED (for Transposon Ellen Dempsey), an autonomous cousin that differs significantly from MuDR. Element excision and reinsertion appear to require both proteins encoded by MuDR, but only the single protein encoded by TED. Germinal excisions, rare with MuDR, are common with TED, but arise in one of the mitotic divisions of the gametophyte, rather than at meiosis. Instead, transposition-deficient elements arise at meiosis, suggesting that the double-strand breaks produced by element excision are repaired differently in mitosis and meiosis. Unlike MuDR, TED is a very low-copy transposon whose number and activity do not undergo dramatic changes upon inbreeding or outcrossing. Like MuDR, TED transposes mostly to unlinked sites and can form circular transposition products. Sequences closer to TED than to MuDR were detected only in the grasses, suggesting a rather recent evolutionary split from a common ancestor.

Evolutionary Expansion of the Amidohydrolase Superfamily in Bacteria in Response to the Synthetic Compounds Molinate and Diuron

Science.gov (United States)

Sugrue, Elena; Fraser, Nicholas J.; Hopkins, Davis H.; Carr, Paul D.; Khurana, Jeevan L.; Oakeshott, John G.; Scott, Colin

2015-01-01

The amidohydrolase superfamily has remarkable functional diversity, with considerable structural and functional annotation of known sequences. In microbes, the recent evolution of several members of this family to catalyze the breakdown of environmental xenobiotics is not well understood. An evolutionary transition from binuclear to mononuclear metal ion coordination at the active sites of these enzymes could produce large functional changes such as those observed in nature, but there are few clear examples available to support this hypothesis. To investigate the role of binuclear-mononuclear active-site transitions in the evolution of new function in this superfamily, we have characterized two recently evolved enzymes that catalyze the hydrolysis of the synthetic herbicides molinate (MolA) and phenylurea (PuhB). In this work, the crystal structures, mutagenesis, metal ion analysis, and enzyme kinetics of both MolA and PuhB establish that these enzymes utilize a mononuclear active site. However, bioinformatics and structural comparisons reveal that the closest putative ancestor of these enzymes had a binuclear active site, indicating that a binuclear-mononuclear transition has occurred. These proteins may represent examples of evolution modifying the characteristics of existing catalysts to satisfy new requirements, specifically, metal ion rearrangement leading to large leaps in activity that would not otherwise be possible. PMID:25636851

Topological variation in the evolution of new reactions in functionally diverse enzyme superfamilies.

Science.gov (United States)

Meng, Elaine C; Babbitt, Patricia C

2011-06-01

In functionally diverse enzyme superfamilies (SFs), conserved structural and active site features reflect catalytic capabilities 'hard-wired' in each SF architecture. Overlaid on this foundation, evolutionary changes in active site machinery, structural topology and other aspects of structural organization and interactions support the emergence of new reactions, mechanisms, and substrate specificity. This review connects topological with functional variation in each of the haloalkanoic acid dehalogenase (HAD) and vicinal oxygen chelate fold (VOC) SFs and a set of redox-active thioredoxin (Trx)-fold SFs to illustrate a few of the varied themes nature has used to evolve new functions from a limited set of structural scaffolds. Copyright © 2011 Elsevier Ltd. All rights reserved.

T-cell receptor transfer into human T cells with ecotropic retroviral vectors.

Science.gov (United States)

Koste, L; Beissert, T; Hoff, H; Pretsch, L; Türeci, Ö; Sahin, U

2014-05-01

Adoptive T-cell transfer for cancer immunotherapy requires genetic modification of T cells with recombinant T-cell receptors (TCRs). Amphotropic retroviral vectors (RVs) used for TCR transduction for this purpose are considered safe in principle. Despite this, TCR-coding and packaging vectors could theoretically recombine to produce replication competent vectors (RCVs), and transduced T-cell preparations must be proven free of RCV. To eliminate the need for RCV testing, we transduced human T cells with ecotropic RVs so potential RCV would be non-infectious for human cells. We show that transfection of synthetic messenger RNA encoding murine cationic amino-acid transporter 1 (mCAT-1), the receptor for murine retroviruses, enables efficient transient ecotropic transduction of human T cells. mCAT-1-dependent transduction was more efficient than amphotropic transduction performed in parallel, and preferentially targeted naive T cells. Moreover, we demonstrate that ecotropic TCR transduction results in antigen-specific restimulation of primary human T cells. Thus, ecotropic RVs represent a versatile, safe and potent tool to prepare T cells for the adoptive transfer.

Gypsy transposition correlates with the production of a retroviral envelope-like protein under the tissue-specific control of the Drosophila flamenco gene.

OpenAIRE

Pélisson, A; Song, S U; Prud'homme, N; Smith, P A; Bucheton, A; Corces, V G

1994-01-01

Gypsy displays striking similarities to vertebrate retroviruses, including the presence of a yet uncharacterized additional open reading frame (ORF3) and the recent evidence for infectivity. It is mobilized with high frequency in the germline of the progeny of females homozygous for the flamenco permissive mutation. We report the characterization of a gypsy subgenomic ORF3 RNA encoding typical retroviral envelope proteins. In females, env expression is strongly repressed by one copy of the no...

The structure of hookworm platelet inhibitor (HPI), a CAP superfamily member from Ancylostoma caninum.

Science.gov (United States)

Ma, Dongying; Francischetti, Ivo M B; Ribeiro, Jose M C; Andersen, John F

2015-06-01

Secreted protein components of hookworm species include a number of representatives of the cysteine-rich/antigen 5/pathogenesis-related 1 (CAP) protein family known as Ancylostoma-secreted proteins (ASPs). Some of these have been considered as candidate antigens for the development of vaccines against hookworms. The functions of most CAP superfamily members are poorly understood, but one form, the hookworm platelet inhibitor (HPI), has been isolated as a putative antagonist of the platelet integrins αIIbβ3 and α2β1. Here, the crystal structure of HPI is described and its structural features are examined in relation to its possible function. The HPI structure is similar to those of other ASPs and shows incomplete conservation of the sequence motifs CAP1 and CAP2 that are considered to be diagnostic of CAP superfamily members. The asymmetric unit of the HPI crystal contains a dimer with an extensive interaction interface, but chromatographic measurements indicate that it is primarily monomeric in solution. In the dimeric structure, the putative active-site cleft areas from both monomers are united into a single negatively charged depression. A potential Lys-Gly-Asp disintegrin-like motif was identified in the sequence of HPI, but is not positioned at the apex of a tight turn, making it unlikely that it interacts with the integrin. Recombinant HPI produced in Escherichia coli was found not to inhibit the adhesion of human platelets to collagen or fibrinogen, despite having a native structure as shown by X-ray diffraction. This result corroborates previous analyses of recombinant HPI and suggests that it might require post-translational modification or have a different biological function.

Computation-Facilitated Assignment of Function in the Enolase Superfamily: A Regiochemically Distinct Galactarate Dehydratase from Oceanobacillus iheyensis†

Science.gov (United States)

Rakus, John F.; Kalyanaraman, Chakrapani; Fedorov, Alexander A.; Fedorov, Elena V.; Mills-Groninger, Fiona P.; Toro, Rafael; Bonanno, Jeffrey; Bain, Kevin; Sauder, J. Michael; Burley, Stephen K.; Almo, Steven C.; Jacobson, Matthew P.; Gerlt, John A.

2009-01-01

The structure of an uncharacterized member of the enolase superfamily from Oceanobacillus iheyensis (GI: 23100298; IMG locus tag Ob2843; PDB Code 2OQY) was determined by the New York SGX Research Center for Structural Genomics (NYSGXRC). The structure contained two Mg2+ ions located 10.4 Å from one another, with one located in the canonical position in the (β/α)7β-barrel domain (although the ligand at the end of the fifth β-strand is His, unprecedented in structurally characterized members of the superfamily); the second is located in a novel site within the capping domain. In silico docking of a library of mono- and diacid sugars to the active site predicted a diacid sugar as a likely substrate. Activity screening of a physical library of acid sugars identified galactarate as the substrate (kcat = 6.8 s−1, KM = 620 μM; kcat/KM = 1.1 × 104 M−1 s−1), allowing functional assignment of Ob2843 as galactarate dehydratase (GalrD-II) The structure of a complex of the catalytically impaired Y90F mutant with Mg2+ and galactarate allowed identification of a Tyr 164-Arg 162 dyad as the base that initiates the reaction by abstraction of the α-proton and Tyr 90 as the acid that facilitates departure of the β-OH leaving group. The enzyme product is 2-keto-3-deoxy-D-threo-4,5-dihydroxyadipate, the enantiomer of the product obtained in the GalrD reaction catalyzed by a previously characterized bifunctional L-talarate/galactarate dehydratase (TalrD/GalrD). On the basis of the different active site structures and different regiochemistries, we recognize that these functions represent an example of apparent, not actual, convergent evolution of function. The structure of GalrD-II and its active site architecture allow identification of the seventh functionally and structurally characterized subgroup in the enolase superfamily. This study provides an additional example that an integrated sequence/structure-based strategy employing computational approaches is a viable

Identifying activated T cells in reconstituted RAG deficient mice using retrovirally transduced Pax5 deficient pro-B cells.

Directory of Open Access Journals (Sweden)

Nadesan Gajendran

Full Text Available Various methods have been used to identify activated T cells such as binding of MHC tetramers and expression of cell surface markers in addition to cytokine-based assays. In contrast to these published methods, we here describe a strategy to identify T cells that respond to any antigen and track the fate of these activated T cells. We constructed a retroviral double-reporter construct with enhanced green fluorescence protein (EGFP and a far-red fluorescent protein from Heteractis crispa (HcRed. LTR-driven EGFP expression was used to enrich and identify transduced cells, while HcRed expression is driven by the CD40Ligand (CD40L promoter, which is inducible and enables the identification and cell fate tracing of T cells that have responded to infection/inflammation. Pax5 deficient pro-B cells that can give rise to different hematopoietic cells like T cells, were retrovirally transduced with this double-reporter cassette and were used to reconstitute the T cell pool in RAG1 deficient mice that lack T and B cells. By using flow cytometry and histology, we identified activated T cells that had developed from Pax5 deficient pro-B cells and responded to infection with the bacterial pathogen Listeria monocytogenes. Microscopic examination of organ sections allowed visual identification of HcRed-expressing cells. To further characterize the immune response to a given stimuli, this strategy can be easily adapted to identify other cells of the hematopoietic system that respond to infection/inflammation. This can be achieved by using an inducible reporter, choosing the appropriate promoter, and reconstituting mice lacking cells of interest by injecting gene-modified Pax5 deficient pro-B cells.

Multidrug resistance and retroviral transduction potential in human small cell lung cancer cell lines

DEFF Research Database (Denmark)

Theilade, M D; Gram, G J; Jensen, P B

1999-01-01

Multidrug resistance (MDR) remains a major problem in the successful treatment of small cell lung cancer (SCLC). New treatment strategies are needed, such as gene therapy specifically targeting the MDR cells in the tumor. Retroviral LacZ gene-containing vectors that were either pseudotyped...... for the gibbon ape leukemia virus (GALV-1) receptor or had specificity for the amphotropic murine leukemia virus (MLV-A) receptor were used for transduction of five SCLC cell lines differing by a range of MDR mechanisms. Transduction efficiencies in these cell lines were compared by calculating the percentage...... of blue colonies after X-Gal staining of the cells grown in soft agar. All examined SCLC cell lines were transducible with either vector. Transduction efficiencies varied from 5.7% to 33.5% independent of the presence of MDR. These results indicate that MDR does not severely impair transduction of SCLC...

HIV-1 integrase inhibitors are substrates for the multidrug transporter MDR1-P-glycoprotein

Directory of Open Access Journals (Sweden)

Cara Andrea

2007-03-01

Full Text Available Abstract Background The discovery of diketoacid-containing derivatives as inhibitors of HIV-1 Integrase (IN (IN inhibitors, IINs has played a major role in validating this enzyme as an important target for antiretroviral therapy. Since the in vivo efficacy depends on access of these drugs to intracellular sites where HIV-1 replicates, we determined whether the IINs are recognized by the multidrug transporter MDR1-P-glycoprotein (P-gp thereby reducing their intracellular accumulation. To address the effect of IINs on drug transport, nine quinolonyl diketo acid (DKA derivatives active on the HIV-1 IN strand transfer (ST step and with EC50 ranging from 1.83 to >50 μm in cell-based assays were tested for their in vitro interaction with P-gp in the CEM-MDR cell system. IINs were investigated for the inhibition and induction of the P-gp function and expression as well as for multidrug resistance (MDR reversing ability. Results The HIV-1 IINs act as genuine P-gp substrates by inhibiting doxorubicin efflux and inducing P-gp functional conformation changes as evaluated by the modulation of UIC2 mAb epitope. Further, IINs chemosensitize MDR cells to vinblastine and induce P-gp expression in drug sensitive revertants of CEM-MDR cells. Conclusion To our knowledge, this is the first demonstration that HIV-1 IINs are P-gp substrates. This biological property may influence the absorption, distribution and elimination of these novels anti HIV-1 compounds.

TED, an Autonomous and Rare Maize Transposon of the Mutator Superfamily with a High Gametophytic Excision Frequency[W

Science.gov (United States)

Li, Yubin; Harris, Linda; Dooner, Hugo K.

2013-01-01

Mutator (Mu) elements, one of the most diverse superfamilies of DNA transposons, are found in all eukaryotic kingdoms, but are particularly numerous in plants. Most of the present knowledge on the transposition behavior of this superfamily comes from studies of the maize (Zea mays) Mu elements, whose transposition is mediated by the autonomous Mutator-Don Robertson (MuDR) element. Here, we describe the maize element TED (for Transposon Ellen Dempsey), an autonomous cousin that differs significantly from MuDR. Element excision and reinsertion appear to require both proteins encoded by MuDR, but only the single protein encoded by TED. Germinal excisions, rare with MuDR, are common with TED, but arise in one of the mitotic divisions of the gametophyte, rather than at meiosis. Instead, transposition-deficient elements arise at meiosis, suggesting that the double-strand breaks produced by element excision are repaired differently in mitosis and meiosis. Unlike MuDR, TED is a very low-copy transposon whose number and activity do not undergo dramatic changes upon inbreeding or outcrossing. Like MuDR, TED transposes mostly to unlinked sites and can form circular transposition products. Sequences closer to TED than to MuDR were detected only in the grasses, suggesting a rather recent evolutionary split from a common ancestor. PMID:24038653

Melanophore migration and survival during zebrafish adult pigment stripe development require the immunoglobulin superfamily adhesion molecule Igsf11.

Science.gov (United States)

Eom, Dae Seok; Inoue, Shinya; Patterson, Larissa B; Gordon, Tiffany N; Slingwine, Rebecca; Kondo, Shigeru; Watanabe, Masakatsu; Parichy, David M

2012-01-01

The zebrafish adult pigment pattern has emerged as a useful model for understanding the development and evolution of adult form as well as pattern-forming mechanisms more generally. In this species, a series of horizontal melanophore stripes arises during the larval-to-adult transformation, but the genetic and cellular bases for stripe formation remain largely unknown. Here, we show that the seurat mutant phenotype, consisting of an irregular spotted pattern, arises from lesions in the gene encoding Immunoglobulin superfamily member 11 (Igsf11). We find that Igsf11 is expressed by melanophores and their precursors, and we demonstrate by cell transplantation and genetic rescue that igsf11 functions autonomously to this lineage in promoting adult stripe development. Further analyses of cell behaviors in vitro, in vivo, and in explant cultures ex vivo demonstrate that Igsf11 mediates adhesive interactions and that mutants for igsf11 exhibit defects in both the migration and survival of melanophores and their precursors. These findings identify the first in vivo requirements for igsf11 as well as the first instance of an immunoglobulin superfamily member functioning in pigment cell development and patterning. Our results provide new insights into adult pigment pattern morphogenesis and how cellular interactions mediate pattern formation.

Melanophore migration and survival during zebrafish adult pigment stripe development require the immunoglobulin superfamily adhesion molecule Igsf11.

Directory of Open Access Journals (Sweden)

Dae Seok Eom

Full Text Available The zebrafish adult pigment pattern has emerged as a useful model for understanding the development and evolution of adult form as well as pattern-forming mechanisms more generally. In this species, a series of horizontal melanophore stripes arises during the larval-to-adult transformation, but the genetic and cellular bases for stripe formation remain largely unknown. Here, we show that the seurat mutant phenotype, consisting of an irregular spotted pattern, arises from lesions in the gene encoding Immunoglobulin superfamily member 11 (Igsf11. We find that Igsf11 is expressed by melanophores and their precursors, and we demonstrate by cell transplantation and genetic rescue that igsf11 functions autonomously to this lineage in promoting adult stripe development. Further analyses of cell behaviors in vitro, in vivo, and in explant cultures ex vivo demonstrate that Igsf11 mediates adhesive interactions and that mutants for igsf11 exhibit defects in both the migration and survival of melanophores and their precursors. These findings identify the first in vivo requirements for igsf11 as well as the first instance of an immunoglobulin superfamily member functioning in pigment cell development and patterning. Our results provide new insights into adult pigment pattern morphogenesis and how cellular interactions mediate pattern formation.

New method to analyze super-family events observed with emulsion chambers

International Nuclear Information System (INIS)

Amenomori, M.

1997-01-01

The authors have developed a clustering method to analyze family events observed with emulsion chambers at high mountains. The main purpose of this analysis is to estimate the main production height of individual events, angular spread of gamma-rays in each event and so on. These enable them to investigate hadronic interactions at energies over 10 16 eV inaccessible by the present high-energy accelerators. they examined their clustering method using Monte Carlo events, and found that for the family events whose production height is low (within 2-3 km above the observation point in air), their production heights and lateral spreads are well reproduced. They further applied their method to the super-family events (ΣE γ > 1000 TeV) observed with emulsion chambers at Mt. Kanbala (5500 m above sea-level). The results seem to suggest that particle production with large transverse momentum occurs with considerable frequency even in the fragmentation region in the energy region over 10 16 eV

Genome-wide identification of nuclear receptor (NR) superfamily genes in the copepod Tigriopus japonicus.

Science.gov (United States)

Hwang, Dae-Sik; Lee, Bo-Young; Kim, Hui-Su; Lee, Min Chul; Kyung, Do-Hyun; Om, Ae-Son; Rhee, Jae-Sung; Lee, Jae-Seong

2014-11-18

Nuclear receptors (NRs) are a large superfamily of proteins defined by a DNA-binding domain (DBD) and a ligand-binding domain (LBD). They function as transcriptional regulators to control expression of genes involved in development, homeostasis, and metabolism. The number of NRs differs from species to species, because of gene duplications and/or lineage-specific gene losses during metazoan evolution. Many NRs in arthropods interact with the ecdysteroid hormone and are involved in ecdysone-mediated signaling in arthropods. The nuclear receptor superfamily complement has been reported in several arthropods, including crustaceans, but not in copepods. We identified the entire NR repertoire of the copepod Tigriopus japonicus, which is an important marine model species for ecotoxicology and environmental genomics. Using whole genome and transcriptome sequences, we identified a total of 31 nuclear receptors in the genome of T. japonicus. Nomenclature of the nuclear receptors was determined based on the sequence similarities of the DNA-binding domain (DBD) and ligand-binding domain (LBD). The 7 subfamilies of NRs separate into five major clades (subfamilies NR1, NR2, NR3, NR4, and NR5/6). Although the repertoire of NR members in, T. japonicus was similar to that reported for other arthropods, there was an expansion of the NR1 subfamily in Tigriopus japonicus. The twelve unique nuclear receptors identified in T. japonicus are members of NR1L. This expansion may be a unique lineage-specific feature of crustaceans. Interestingly, E78 and HR83, which are present in other arthropods, were absent from the genomes of T. japonicus and two congeneric copepod species (T. japonicus and Tigriopus californicus), suggesting copepod lineage-specific gene loss. We identified all NR receptors present in the copepod, T. japonicus. Knowledge of the copepod nuclear receptor repertoire will contribute to a better understanding of copepod- and crustacean-specific NR evolution.

Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (USA))

1988-11-01

Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human {alpha}{sub 1}-antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the {alpha}{sub 1} antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes.

Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

International Nuclear Information System (INIS)

Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C.

1988-01-01

Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human α 1 -antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the α 1 antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes

At the Perphery of the Amidohydrolase Superfamily: Bh0493 from Bacillus halodurans Catalyzes the Isomerization of D-Galacturonate to D-Tagaturonate

Energy Technology Data Exchange (ETDEWEB)

Nguyen,T.; Brown, S.; Fedorov, A.; Fedorov, E.; Babbitt, P.; Almo, S.; Raushel, F.

2008-01-01

The amidohydrolase superfamily is a functionally diverse set of enzymes that catalyzes predominantly hydrolysis reactions involving sugars, nucleic acids, amino acids, and organophosphate esters. One of the most divergent members of this superfamily, uronate isomerase from Escherichia coli, catalyzes the isomerization of d-glucuronate to d-fructuronate and d-galacturonate to d-tagaturonate and is the only uronate isomerase in this organism. A gene encoding a putative uronate isomerase in Bacillus halodurans (Bh0705) was identified based on sequence similarity to uronate isomerases from other organisms. Kinetic evidence indicates that Bh0705 is relatively specific for the isomerization of d-glucuronate to d-fructuronate, confirming this functional assignment. Despite a low sequence identity to all other characterized uronate isomerases, phylogenetic and network-based analysis suggests that a second gene in this organism, Bh0493, is also a uronate isomerase, although it is an outlier in the group, with <20% sequence identity to any other characterized uronate isomerase from another species. The elucidation of the X-ray structure at a resolution of 2.0 Angstroms confirms that Bh0493 is a member of the amidohydrolase superfamily with conserved residues common to other members of the uronate isomerase family. Functional characterization of this protein shows that unlike Bh0705, Bh0493 can utilize both d-glucuronate and d-galacturonate as substrates. In B. halodurans, Bh0705 is found in an operon for the metabolism of d-glucuronate, whereas Bh0493 is in an operon for the metabolism of d-galacturonate. These results provide the first identification of a uronate isomerase that operates in a pathway distinct from that for d-glucuronate. While most organisms that contain this pathway have only one gene for a uronate isomerase, sequence analysis and operon context show that five other organisms also appear to have two genes and one organism appears to have three genes for

Integrase inhibitors in late pregnancy and rapid HIV viral load reduction.

Science.gov (United States)

Rahangdale, Lisa; Cates, Jordan; Potter, JoNell; Badell, Martina L; Seidman, Dominika; Miller, Emilly S; Coleman, Jenell S; Lazenby, Gweneth B; Levison, Judy; Short, William R; Yawetz, Sigal; Ciaranello, Andrea; Livingston, Elizabeth; Duthely, Lunthita; Rimawi, Bassam H; Anderson, Jean R; Stringer, Elizabeth M

2016-03-01

Minimizing time to HIV viral suppression is critical in pregnancy. Integrase strand transfer inhibitors (INSTIs), like raltegravir, are known to rapidly suppress plasma HIV RNA in nonpregnant adults. There are limited data in pregnant women. We describe time to clinically relevant reduction in HIV RNA in pregnant women using INSTI-containing and non-INSTI-containing antiretroviral therapy (ART) options. We conducted a retrospective cohort study of pregnant HIV-infected women in the United States from 2009 through 2015. We included women who initiated ART, intensified their regimen, or switched to a new regimen due to detectable viremia (HIV RNA >40 copies/mL) at ≥20 weeks gestation. Among women with a baseline HIV RNA permitting 1-log reduction, we estimated time to 1-log RNA reduction using the Kaplan-Meier estimator comparing women starting/adding an INSTI in their regimen vs other ART. To compare groups with similar follow-up time, we also conducted a subgroup analysis limited to women with ≤14 days between baseline and follow-up RNA data. This study describes 101 HIV-infected pregnant women from 11 US clinics. In all, 75% (76/101) of women were not taking ART at baseline; 24 were taking non-INSTI containing ART, and 1 received zidovudine monotherapy. In all, 39% (39/101) of women started an INSTI-containing regimen or added an INSTI to their ART regimen. Among 90 women with a baseline HIV RNA permitting 1-log reduction, the median time to 1-log RNA reduction was 8 days (interquartile range [IQR], 7-14) in the INSTI group vs 35 days (IQR, 20-53) in the non-INSTI ART group (P pregnancy. Inclusion of an INSTI may play a role in optimal reduction of HIV RNA for HIV-infected pregnant women presenting late to care or failing initial therapy. Larger studies are urgently needed to assess the safety and effectiveness of this approach. Copyright © 2016 Elsevier Inc. All rights reserved.

Isolation, characterization, and genetic complementation of a cellular mutant resistant to retroviral infection

Science.gov (United States)

Agarwal, Sumit; Harada, Josephine; Schreifels, Jeffrey; Lech, Patrycja; Nikolai, Bryan; Yamaguchi, Tomoyuki; Chanda, Sumit K.; Somia, Nikunj V.

2006-01-01

By using a genetic screen, we have isolated a mammalian cell line that is resistant to infection by retroviruses that are derived from the murine leukemia virus, human immunodeficiency virus type 1, and feline immunodeficiency virus. We demonstrate that the cell line is genetically recessive for the resistance, and hence it is lacking a factor enabling infection by retroviruses. The block to infection is early in the life cycle, at the poorly understood uncoating stage. We implicate the proteasome at uncoating by completely rescuing the resistant phenotype with the proteasomal inhibitor MG-132. We further report on the complementation cloning of a gene (MRI, modulator of retrovirus infection) that can also act to reverse the inhibition of infection in the mutant cell line. These data implicate a role for the proteasome during uncoating, and they suggest that MRI is a regulator of this activity. Finally, we reconcile our findings and other published data to suggest a model for the involvement of the proteasome in the early phase of the retroviral life cycle. PMID:17043244

CD177: A member of the Ly-6 gene superfamily involved with neutrophil proliferation and polycythemia vera

Directory of Open Access Journals (Sweden)

Bettinotti Maria

2004-03-01

Full Text Available Abstract Genes in the Leukocyte Antigen 6 (Ly-6 superfamily encode glycosyl-phosphatidylinositol (GPI anchored glycoproteins (gp with conserved domains of 70 to 100 amino acids and 8 to 10 cysteine residues. Murine Ly-6 genes encode important lymphocyte and hematopoietic stem cell antigens. Recently, a new member of the human Ly-6 gene superfamily has been described, CD177. CD177 is polymorphic and has at least two alleles, PRV-1 and NB1. CD177 was first described as PRV-1, a gene that is overexpressed in neutrophils from approximately 95% of patients with polycythemia vera and from about half of patients with essential thrombocythemia. CD177 encodes NB1 gp, a 58–64 kD GPI gp that is expressed by neutrophils and neutrophil precursors. NB1 gp carries Human Neutrophil Antigen (HNA-2a. Investigators working to identify the gene encoding NB1 gp called the CD177 allele they described NB1. NB1 gp is unusual in that neutrophils from some healthy people lack the NB1 gp completely and in most people NB1 gp is expressed by a subpopulation of neutrophils. The function of NB1 gp and the role of CD177 in the pathogenesis and clinical course of polycythemia vera and essential thrombocythemia are not yet known. However, measuring neutrophil CD177 mRNA levels has become an important marker for diagnosing the myeloproliferative disorders polycythemia vera and essential thrombocythemia.

Combining protein sequence, structure, and dynamics: A novel approach for functional evolution analysis of PAS domain superfamily.

Science.gov (United States)

Dong, Zheng; Zhou, Hongyu; Tao, Peng

2018-02-01

PAS domains are widespread in archaea, bacteria, and eukaryota, and play important roles in various functions. In this study, we aim to explore functional evolutionary relationship among proteins in the PAS domain superfamily in view of the sequence-structure-dynamics-function relationship. We collected protein sequences and crystal structure data from RCSB Protein Data Bank of the PAS domain superfamily belonging to three biological functions (nucleotide binding, photoreceptor activity, and transferase activity). Protein sequences were aligned and then used to select sequence-conserved residues and build phylogenetic tree. Three-dimensional structure alignment was also applied to obtain structure-conserved residues. The protein dynamics were analyzed using elastic network model (ENM) and validated by molecular dynamics (MD) simulation. The result showed that the proteins with same function could be grouped by sequence similarity, and proteins in different functional groups displayed statistically significant difference in their vibrational patterns. Interestingly, in all three functional groups, conserved amino acid residues identified by sequence and structure conservation analysis generally have a lower fluctuation than other residues. In addition, the fluctuation of conserved residues in each biological function group was strongly correlated with the corresponding biological function. This research suggested a direct connection in which the protein sequences were related to various functions through structural dynamics. This is a new attempt to delineate functional evolution of proteins using the integrated information of sequence, structure, and dynamics. © 2017 The Protein Society.

Genome-wide retroviral insertional tagging of genes involved in cancer in Cdkn2a-deficient mice

DEFF Research Database (Denmark)

Lund, Anders H; Turner, Geoffrey; Trubetskoy, Alla

2002-01-01

We have used large-scale insertional mutagenesis to identify functional landmarks relevant to cancer in the recently completed mouse genome sequence. We infected Cdkn2a(-/-) mice with Moloney murine leukemia virus (MoMuLV) to screen for loci that can participate in tumorigenesis in collaboration...... retroviral integration sites and mapped them against the mouse genome sequence databases from Celera and Ensembl. In addition to 17 insertions targeting gene loci known to be cancer-related, we identified a total of 37 new common insertion sites (CISs), of which 8 encode components of signaling pathways...... that are involved in cancer. The effectiveness of large-scale insertional mutagenesis in a sensitized genetic background is demonstrated by the preference for activation of MAP kinase signaling, collaborating with Cdkn2a loss in generating the lymphoid and myeloid tumors. Collectively, our results show that large...

Accelerated generation of human induced pluripotent stem cells with retroviral transduction and chemical inhibitors under physiological hypoxia

Energy Technology Data Exchange (ETDEWEB)

Shimada, Hidenori [Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Hashimoto, Yoshiya [Department of Biomaterials, Osaka Dental University, 8-1, Hanazonocho, Kuzuha, Hirakatashi, Osaka 573-1121 (Japan); Nakada, Akira; Shigeno, Keiji [Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Nakamura, Tatsuo, E-mail: nakamura@frontier.kyoto-u.ac.jp [Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan)

2012-01-13

Highlights: Black-Right-Pointing-Pointer Very rapid generation of human iPS cells under optimized conditions. Black-Right-Pointing-Pointer Five chemical inhibitors under hypoxia boosted reprogramming. Black-Right-Pointing-Pointer We performed genome-wide DNA methylation analysis. -- Abstract: Induced pluripotent stem (iPS) cells are generated from somatic cells by the forced expression of a defined set of pluripotency-associated transcription factors. Human iPS cells can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for extra-embryonic tissues. This technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large amounts of disease-specific cells for biomedical research. Despite their great potential, the long reprogramming process (up to 1 month) remains one of the most significant challenges facing standard virus-mediated methodology. In this study, we report the accelerated generation of human iPS cells from adipose-derived stem (ADS) cells, using a new combination of chemical inhibitors under a setting of physiological hypoxia in conjunction with retroviral transduction of Oct4, Sox2, Klf4, and L-Myc. Under optimized conditions, we observed human embryonic stem (ES)-like cells as early as 6 days after the initial retroviral transduction. This was followed by the emergence of fully reprogrammed cells bearing Tra-1-81-positive and DsRed transgene-silencing properties on day 10. The resulting cell lines resembled human ES cells in many respects including proliferation rate, morphology, pluripotency-associated markers, global gene expression patterns, genome-wide DNA methylation states, and the ability to differentiate into all three of the germ layers, both in vitro and in vivo. Our method, when combined with chemical inhibitors under conditions of physiological hypoxia, offers a powerful tool for rapidly

Accelerated generation of human induced pluripotent stem cells with retroviral transduction and chemical inhibitors under physiological hypoxia

International Nuclear Information System (INIS)

Shimada, Hidenori; Hashimoto, Yoshiya; Nakada, Akira; Shigeno, Keiji; Nakamura, Tatsuo

2012-01-01

Highlights: ► Very rapid generation of human iPS cells under optimized conditions. ► Five chemical inhibitors under hypoxia boosted reprogramming. ► We performed genome-wide DNA methylation analysis. -- Abstract: Induced pluripotent stem (iPS) cells are generated from somatic cells by the forced expression of a defined set of pluripotency-associated transcription factors. Human iPS cells can be propagated indefinitely, while maintaining the capacity to differentiate into all cell types in the body except for extra-embryonic tissues. This technology not only represents a new way to use individual-specific stem cells for regenerative medicine but also constitutes a novel method to obtain large amounts of disease-specific cells for biomedical research. Despite their great potential, the long reprogramming process (up to 1 month) remains one of the most significant challenges facing standard virus-mediated methodology. In this study, we report the accelerated generation of human iPS cells from adipose-derived stem (ADS) cells, using a new combination of chemical inhibitors under a setting of physiological hypoxia in conjunction with retroviral transduction of Oct4, Sox2, Klf4, and L-Myc. Under optimized conditions, we observed human embryonic stem (ES)-like cells as early as 6 days after the initial retroviral transduction. This was followed by the emergence of fully reprogrammed cells bearing Tra-1-81-positive and DsRed transgene-silencing properties on day 10. The resulting cell lines resembled human ES cells in many respects including proliferation rate, morphology, pluripotency-associated markers, global gene expression patterns, genome-wide DNA methylation states, and the ability to differentiate into all three of the germ layers, both in vitro and in vivo. Our method, when combined with chemical inhibitors under conditions of physiological hypoxia, offers a powerful tool for rapidly generating bona fide human iPS cells and facilitates the application of i

A QSAR study of integrase strand transfer inhibitors based on a large set of pyrimidine, pyrimidone, and pyridopyrazine carboxamide derivatives

Science.gov (United States)

de Campos, Luana Janaína; de Melo, Eduardo Borges

2017-08-01

In the present study, 199 compounds derived from pyrimidine, pyrimidone and pyridopyrazine carboxamides with inhibitory activity against HIV-1 integrase were modeled. Subsequently, a multivariate QSAR study was conducted with 54 molecules employed by Ordered Predictors Selection (OPS) and Partial Least Squares (PLS) for the selection of variables and model construction, respectively. Topological, electrotopological, geometric, and molecular descriptors were used. The selected real model was robust and free from chance correlation; in addition, it demonstrated favorable internal and external statistical quality. Once statistically validated, the training model was used to predict the activity of a second data set (n = 145). The root mean square deviation (RMSD) between observed and predicted values was 0.698. Although it is a value outside of the standards, only 15 (10.34%) of the samples exhibited higher residual values than 1 log unit, a result considered acceptable. Results of Williams and Euclidean applicability domains relative to the prediction showed that the predictions did not occur by extrapolation and that the model is representative of the chemical space of test compounds.

Contribution of the C-terminal region within the catalytic core domain of HIV-1 integrase to yeast lethality, chromatin binding and viral replication

Directory of Open Access Journals (Sweden)

Belhumeur Pierre

2008-11-01

Full Text Available Abstract Background HIV-1 integrase (IN is a key viral enzymatic molecule required for the integration of the viral cDNA into the genome. Additionally, HIV-1 IN has been shown to play important roles in several other steps during the viral life cycle, including reverse transcription, nuclear import and chromatin targeting. Interestingly, previous studies have demonstrated that the expression of HIV-1 IN induces the lethal phenotype in some strains of Saccharomyces cerevisiae. In this study, we performed mutagenic analyses of the C-terminal region of the catalytic core domain of HIV-1 IN in order to delineate the critical amino acid(s and/or motif(s required for the induction of the lethal phenotype in the yeast strain HP16, and to further elucidate the molecular mechanism which causes this phenotype. Results Our study identified three HIV-1 IN mutants, V165A, A179P and KR186,7AA, located in the C-terminal region of the catalytic core domain of IN that do not induce the lethal phenotype in yeast. Chromatin binding assays in yeast and mammalian cells demonstrated that these IN mutants were impaired for the ability to bind chromatin. Additionally, we determined that while these IN mutants failed to interact with LEDGF/p75, they retained the ability to bind Integrase interactor 1. Furthermore, we observed that VSV-G-pseudotyped HIV-1 containing these IN mutants was unable to replicate in the C8166 T cell line and this defect was partially rescued by complementation with the catalytically inactive D64E IN mutant. Conclusion Overall, this study demonstrates that three mutations located in the C-terminal region of the catalytic core domain of HIV-1 IN inhibit the IN-induced lethal phenotype in yeast by inhibiting the binding of IN to the host chromatin. These results demonstrate that the C-terminal region of the catalytic core domain of HIV-1 IN is important for binding to host chromatin and is crucial for both viral replication and the promotion of

Computational Identification of the Paralogs and Orthologs of Human Cytochrome P450 Superfamily and the Implication in Drug Discovery

Directory of Open Access Journals (Sweden)

Shu-Ting Pan

2016-06-01

Full Text Available The human cytochrome P450 (CYP superfamily consisting of 57 functional genes is the most important group of Phase I drug metabolizing enzymes that oxidize a large number of xenobiotics and endogenous compounds, including therapeutic drugs and environmental toxicants. The CYP superfamily has been shown to expand itself through gene duplication, and some of them become pseudogenes due to gene mutations. Orthologs and paralogs are homologous genes resulting from speciation or duplication, respectively. To explore the evolutionary and functional relationships of human CYPs, we conducted this bioinformatic study to identify their corresponding paralogs, homologs, and orthologs. The functional implications and implications in drug discovery and evolutionary biology were then discussed. GeneCards and Ensembl were used to identify the paralogs of human CYPs. We have used a panel of online databases to identify the orthologs of human CYP genes: NCBI, Ensembl Compara, GeneCards, OMA (“Orthologous MAtrix” Browser, PATHER, TreeFam, EggNOG, and Roundup. The results show that each human CYP has various numbers of paralogs and orthologs using GeneCards and Ensembl. For example, the paralogs of CYP2A6 include CYP2A7, 2A13, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 2F1, 2J2, 2R1, 2S1, 2U1, and 2W1; CYP11A1 has 6 paralogs including CYP11B1, 11B2, 24A1, 27A1, 27B1, and 27C1; CYP51A1 has only three paralogs: CYP26A1, 26B1, and 26C1; while CYP20A1 has no paralog. The majority of human CYPs are well conserved from plants, amphibians, fishes, or mammals to humans due to their important functions in physiology and xenobiotic disposition. The data from different approaches are also cross-validated and validated when experimental data are available. These findings facilitate our understanding of the evolutionary relationships and functional implications of the human CYP superfamily in drug discovery.

The First Synthesis and Anti-retroviral Activity of 5',5'-Difluoro-3'-Hydroxy-Apiosyl Nucleoside Cyclomonophosphonic Acid Analogs

Energy Technology Data Exchange (ETDEWEB)

Kim, Seyeon; Hong, Joon Hee [Chosun University, Gwangju (Korea, Republic of)

2016-04-15

The first synthesis of novel 5',5'-difluoro-30-hydroxy apiose nucleoside cyclomonophosphonic acid analogs was performed as potent anti-retroviral agents. Phosphonation was performed by direct displacement of a triflate intermediate with diethyl(lithiodifluoromethyl) phosphonate to give the corresponding(α, α-difluoroalkyl) phosphonate. Condensation successfully proceeded from a glycosyl donor with persilylated bases to yield the nucleoside phosphonate analogs. Deprotection of diethyl phosphonates provided the target nucleoside cyclomonophosphonic acid analogs. The synthesized nucleoside analogs were subjected to anti-viral screening against the human immunodeficiency virus-1 (HIV-1). Cytosine analogs show significant anti-HIV activity.

An audit on virological efficacy of anti-retroviral therapy in a specialist infectious disease clinic.

LENUS (Irish Health Repository)

Reyad, A

2009-06-01

We have assessed the efficacy of anti retroviral therapy (ART) using undetectable viral load (VL) (<50 RNA copies\\/ml) as a marker of virological success, in patients who have Human Immunodeficiency Virus (HIV) attending the Department of Infectious Disease. A cross-sectional review of patients\\' case notes was used to obtain their demographics and treatment details. 79% (253) of the hospital case notes of clinic population was available for analysis, which represents 90% of those receiving ART in the clinic. 166\\/253 of the cohort were receiving treatment at the time of this study and 95% (157\\/166) of these were on treatment for greater than 6 months. The total virological success rate is 93%, which is comparable to other centres and are as good as those from published clinical trials. 56% of those on therapy who have virological failure were Intravenous Drug Users (IVDUs). Case by case investigation for those with treatment failure is warranted.

CD4 expression on EL4 cells as an epiphenomenon of retroviral transduction and selection.

Science.gov (United States)

Logan, Grant J; Spinoulas, Afroditi; Alexander, Stephen I; Smythe, Jason A; Alexander, Ian E

2004-04-01

The EL4 murine tumour cell line, isolated from a chemically induced lymphoma over 50 years ago, has been extensively exploited in immunological research. The conclusions drawn from many of these studies have been based on the presumption that EL4 cells maintain a stable phenotype during experimental manipulation. To the contrary, we have observed 100-fold greater expression of cell surface CD4 (CD4(high)) on a subpopulation of EL4 cells following retroviral transduction and G418 selection when compared with unmodified populations. Although the mechanism responsible for this effect remains to be elucidated, the unexpected expression of CD4, a molecule that functions as both a coreceptor with the T-cell receptor and ligand for the pro-inflammatory cytokine IL-16, has the potential to influence experimental outcomes. Upregulation of CD4 should be excluded when EL4 cells are utilized in experiments requiring a consistent immuno-phenotype.

Characterization of the Tetraspan Junctional Complex (4JC) superfamily.

Science.gov (United States)

Chou, Amy; Lee, Andre; Hendargo, Kevin J; Reddy, Vamsee S; Shlykov, Maksim A; Kuppusamykrishnan, Harikrishnan; Medrano-Soto, Arturo; Saier, Milton H

2017-03-01

Connexins or innexins form gap junctions, while claudins and occludins form tight junctions. In this study, statistical data, derived using novel software, indicate that these four junctional protein families and eleven other families of channel and channel auxiliary proteins are related by common descent and comprise the Tetraspan (4 TMS) Junctional Complex (4JC) Superfamily. These proteins all share similar 4 transmembrane α-helical (TMS) topologies. Evidence is presented that they arose via an intragenic duplication event, whereby a 2 TMS-encoding genetic element duplicated tandemly to give 4 TMS proteins. In cases where high resolution structural data were available, the conclusion of homology was supported by conducting structural comparisons. Phylogenetic trees reveal the probable relationships of these 15 families to each other. Long homologues containing fusions to other recognizable domains as well as internally duplicated or fused domains are reported. Large "fusion" proteins containing 4JC domains proved to fall predominantly into family-specific patterns as follows: (1) the 4JC domain was N-terminal; (2) the 4JC domain was C-terminal; (3) the 4JC domain was duplicated or occasionally triplicated and (4) mixed fusion types were present. Our observations provide insight into the evolutionary origins and subfunctions of these proteins as well as guides concerning their structural and functional relationships. Copyright © 2016 Elsevier B.V. All rights reserved.

Multiple Receptor Subtypes for the CGRP Super-Family

Directory of Open Access Journals (Sweden)

R. Quirion

2001-01-01

Full Text Available Molecular evidence for the existence of multiple receptors for CGRP has been rather difficult to obtain. Over 10 years after suggesting the existence of at least two classes (CGRP1 and CGRP2 of CGRP receptors on the basis of pharmacological data[1], molecular data on the CGRP2 receptor subtype are still lacking as well as potent and selective antagonists. The situation is somewhat different for the functional CGRP1 subtype which is likely composed of diverse subunits CRLR, RAMP1 and possibly RCP[2]. Moreover, BIBN 4096BS was recently reported as the first nonpeptide highly potent CGRP1 receptor antagonist[3]. However, in situ hybridization and receptor autoradiographic data have clearly shown the existence of major mismatches (e.g., cerebellum between the discrete localization of CRLR, RAMP1, and specific CGRP binding sites supporting the existence of CGRP receptor subtypes. Functional studies have also provided evidence in that regard (for a recent review: [4]. Accordingly, additional studies aiming at cloning additional CGRP receptors are certainly warranted. Similarly, recent evidence from various laboratories including ours suggests the existence of more than one class (CRLR and RAMP2 of adrenomedullin receptors at least in the rat brain. In contrast, most evidence suggests the existence of a single class of amylin receptors. In brief, it appears that multiple receptors or receptor complexes do exist for CGRP and related peptides but their composition is apparently unique among the GPCR super-family and additional data are needed to fully establish the molecular organization of each subtype. Supported by CIHR of Canada.

Tracing the Evolutionary History of the CAP Superfamily of Proteins Using Amino Acid Sequence Homology and Conservation of Splice Sites.

Science.gov (United States)

Abraham, Anup; Chandler, Douglas E

2017-10-01

Proteins of the CAP superfamily play numerous roles in reproduction, innate immune responses, cancer biology, and venom toxicology. Here we document the breadth of the CAP (Cysteine-RIch Secretory Protein (CRISP), Antigen 5, and Pathogenesis-Related) protein superfamily and trace the major events in its evolution using amino acid sequence homology and the positions of exon/intron borders within their genes. Seldom acknowledged in the literature, we find that many of the CAP subfamilies present in mammals, where they were originally characterized, have distinct homologues in the invertebrate phyla. Early eukaryotic CAP genes contained only one exon inherited from prokaryotic predecessors and as evolution progressed an increasing number of introns were inserted, reaching 2-5 in the invertebrate world and 5-15 in the vertebrate world. Focusing on the CRISP subfamily, we propose that these proteins evolved in three major steps: (1) origination of the CAP/PR/SCP domain in bacteria, (2) addition of a small Hinge domain to produce the two-domain SCP-like proteins found in roundworms and anthropoids, and (3) addition of an Ion Channel Regulatory domain, borrowed from invertebrate peptide toxins, to produce full length, three-domain CRISP proteins, first seen in insects and later to diversify into multiple subtypes in the vertebrate world.

Modulating ectopic gene expression levels by using retroviral vectors equipped with synthetic promoters.

Science.gov (United States)

Ferreira, Joshua P; Peacock, Ryan W S; Lawhorn, Ingrid E B; Wang, Clifford L

2011-12-01

The human cytomegalovirus and elongation factor 1α promoters are constitutive promoters commonly employed by mammalian expression vectors. These promoters generally produce high levels of expression in many types of cells and tissues. To generate a library of synthetic promoters capable of generating a range of low, intermediate, and high expression levels, the TATA and CAAT box elements of these promoters were mutated. Other promoter variants were also generated by random mutagenesis. Evaluation using plasmid vectors integrated at a single site in the genome revealed that these various synthetic promoters were capable of expression levels spanning a 40-fold range. Retroviral vectors were equipped with the synthetic promoters and evaluated for their ability to reproduce the graded expression demonstrated by plasmid integration. A vector with a self-inactivating long terminal repeat could neither reproduce the full range of expression levels nor produce stable expression. Using a second vector design, the different synthetic promoters enabled stable expression over a broad range of expression levels in different cell lines. The online version of this article (doi:10.1007/s11693-011-9089-0) contains supplementary material, which is available to authorized users.

Interferon-alpha subtype 11 activates NK cells and enables control of retroviral infection.

Directory of Open Access Journals (Sweden)

Kathrin Gibbert

Full Text Available The innate immune response mediated by cells such as natural killer (NK cells is critical for the rapid containment of virus replication and spread during acute infection. Here, we show that subtype 11 of the type I interferon (IFN family greatly potentiates the antiviral activity of NK cells during retroviral infection. Treatment of mice with IFN-α11 during Friend retrovirus infection (FV significantly reduced viral loads and resulted in long-term protection from virus-induced leukemia. The effect of IFN-α11 on NK cells was direct and signaled through the type I IFN receptor. Furthermore, IFN-α11-mediated activation of NK cells enabled cytolytic killing of FV-infected target cells via the exocytosis pathway. Depletion and adoptive transfer experiments illustrated that NK cells played a major role in successful IFN-α11 therapy. Additional experiments with Mouse Cytomegalovirus infections demonstrated that the therapeutic effect of IFN-α11 is not restricted to retroviruses. The type I IFN subtypes 2 and 5, which bind the same receptor as IFN-α11, did not elicit similar antiviral effects. These results demonstrate a unique and subtype-specific activation of NK cells by IFN-α11.

Two Major Facilitator Superfamily Sugar Transporters from Trichoderma reesei and Their Roles in Induction of Cellulase Biosynthesis*

Science.gov (United States)

Zhang, Weixin; Kou, Yanbo; Xu, Jintao; Cao, Yanli; Zhao, Guolei; Shao, Jing; Wang, Hai; Wang, Zhixing; Bao, Xiaoming; Chen, Guanjun; Liu, Weifeng

2013-01-01

Proper perception of the extracellular insoluble cellulose is key to initiating the rapid synthesis of cellulases by cellulolytic Trichoderma reesei. Uptake of soluble oligosaccharides derived from cellulose hydrolysis represents a potential point of control in the induced cascade. In this study, we identified a major facilitator superfamily sugar transporter Stp1 capable of transporting cellobiose by reconstructing a cellobiose assimilation system in Saccharomyces cerevisiae. The absence of Stp1 in T. reesei resulted in differential cellulolytic response to Avicel versus cellobiose. Transcriptional profiling revealed a different expression profile in the Δstp1 strain from that of wild-type strain in response to Avicel and demonstrated that Stp1 somehow repressed induction of the bulk of major cellulase and hemicellulose genes. Two other putative major facilitator superfamily sugar transporters were, however, up-regulated in the profiling. Deletion of one of them identified Crt1 that was required for growth and enzymatic activity on cellulose or lactose, but was not required for growth or hemicellulase activity on xylan. The essential role of Crt1 in cellulase induction did not seem to rely on its transporting activity because the overall uptake of cellobiose or sophorose by T. reesei was not compromised in the absence of Crt1. Phylogenetic analysis revealed that orthologs of Crt1 exist in the genomes of many filamentous ascomycete fungi capable of degrading cellulose. These data thus shed new light on the mechanism by which T. reesei senses and transmits the cellulose signal and offers potential strategies for strain improvement. PMID:24085297

Evolution of plant virus movement proteins from the 30K superfamily and of their homologs integrated in plant genomes

Energy Technology Data Exchange (ETDEWEB)

Mushegian, Arcady R., E-mail: mushegian2@gmail.com [Division of Molecular and Cellular Biosciences, National Science Foundation, 4201 Wilson Boulevard, Arlington, VA 22230 (United States); Elena, Santiago F., E-mail: sfelena@ibmcp.upv.es [Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, 46022 València (Spain); The Santa Fe Institute, Santa Fe, NM 87501 (United States)

2015-02-15

Homologs of Tobacco mosaic virus 30K cell-to-cell movement protein are encoded by diverse plant viruses. Mechanisms of action and evolutionary origins of these proteins remain obscure. We expand the picture of conservation and evolution of the 30K proteins, producing sequence alignment of the 30K superfamily with the broadest phylogenetic coverage thus far and illuminating structural features of the core all-beta fold of these proteins. Integrated copies of pararetrovirus 30K movement genes are prevalent in euphyllophytes, with at least one copy intact in nearly every examined species, and mRNAs detected for most of them. Sequence analysis suggests repeated integrations, pseudogenizations, and positive selection in those provirus genes. An unannotated 30K-superfamily gene in Arabidopsis thaliana genome is likely expressed as a fusion with the At1g37113 transcript. This molecular background of endopararetrovirus gene products in plants may change our view of virus infection and pathogenesis, and perhaps of cellular homeostasis in the hosts. - Highlights: • Sequence region shared by plant virus “30K” movement proteins has an all-beta fold. • Most euphyllophyte genomes contain integrated copies of pararetroviruses. • These integrated virus genomes often include intact movement protein genes. • Molecular evidence suggests that these “30K” genes may be selected for function.

Human immunodeficiency virus integrase inhibitors efficiently suppress feline immunodeficiency virus replication in vitro and provide a rationale to redesign antiretroviral treatment for feline AIDS

Directory of Open Access Journals (Sweden)

Ciervo Alessandra

2007-10-01

Full Text Available Abstract Background Treatment of feline immunodeficiency virus (FIV infection has been hampered by the absence of a specific combination antiretroviral treatment (ART. Integrase strand transfer inhibitors (INSTIs are emerging as a promising new drug class for HIV-1 treatment, and we evaluated the possibility of inhibiting FIV replication using INSTIs. Methods Phylogenetic analysis of lentiviral integrase (IN sequences was carried out using the PAUP* software. A theoretical three-dimensional structure of the FIV IN catalytic core domain (CCD was obtained by homology modeling based on a crystal structure of HIV-1 IN CCD. The interaction of the transferred strand of viral DNA with the catalytic cavity of FIV IN was deduced from a crystal structure of a structurally similar transposase complexed with transposable DNA. Molecular docking simulations were conducted using a genetic algorithm (GOLD. Antiviral activity was tested in feline lymphoblastoid MBM cells acutely infected with the FIV Petaluma strain. Circular and total proviral DNA was quantified by real-time PCR. Results The calculated INSTI-binding sites were found to be nearly identical in FIV and HIV-1 IN CCDs. The close similarity of primate and feline lentivirus IN CCDs was also supported by phylogenetic analysis. In line with these bioinformatic analyses, FIV replication was efficiently inhibited in acutely infected cell cultures by three investigational INSTIs, designed for HIV-1 and belonging to different classes. Of note, the naphthyridine carboxamide INSTI, L-870,810 displayed an EC50 in the low nanomolar range. Inhibition of FIV integration in situ was shown by real-time PCR experiments that revealed accumulation of circular forms of FIV DNA within cells treated with L-870,810. Conclusion We report a drug class (other than nucleosidic reverse transcriptase inhibitors that is capable of inhibiting FIV replication in vitro. The present study helped establish L-870,810, a compound

Human immunodeficiency virus integrase inhibitors efficiently suppress feline immunodeficiency virus replication in vitro and provide a rationale to redesign antiretroviral treatment for feline AIDS

Science.gov (United States)

Savarino, Andrea; Pistello, Mauro; D'Ostilio, Daniela; Zabogli, Elisa; Taglia, Fabiana; Mancini, Fabiola; Ferro, Stefania; Matteucci, Donatella; De Luca, Laura; Barreca, Maria Letizia; Ciervo, Alessandra; Chimirri, Alba; Ciccozzi, Massimo; Bendinelli, Mauro

2007-01-01

Background Treatment of feline immunodeficiency virus (FIV) infection has been hampered by the absence of a specific combination antiretroviral treatment (ART). Integrase strand transfer inhibitors (INSTIs) are emerging as a promising new drug class for HIV-1 treatment, and we evaluated the possibility of inhibiting FIV replication using INSTIs. Methods Phylogenetic analysis of lentiviral integrase (IN) sequences was carried out using the PAUP* software. A theoretical three-dimensional structure of the FIV IN catalytic core domain (CCD) was obtained by homology modeling based on a crystal structure of HIV-1 IN CCD. The interaction of the transferred strand of viral DNA with the catalytic cavity of FIV IN was deduced from a crystal structure of a structurally similar transposase complexed with transposable DNA. Molecular docking simulations were conducted using a genetic algorithm (GOLD). Antiviral activity was tested in feline lymphoblastoid MBM cells acutely infected with the FIV Petaluma strain. Circular and total proviral DNA was quantified by real-time PCR. Results The calculated INSTI-binding sites were found to be nearly identical in FIV and HIV-1 IN CCDs. The close similarity of primate and feline lentivirus IN CCDs was also supported by phylogenetic analysis. In line with these bioinformatic analyses, FIV replication was efficiently inhibited in acutely infected cell cultures by three investigational INSTIs, designed for HIV-1 and belonging to different classes. Of note, the naphthyridine carboxamide INSTI, L-870,810 displayed an EC50 in the low nanomolar range. Inhibition of FIV integration in situ was shown by real-time PCR experiments that revealed accumulation of circular forms of FIV DNA within cells treated with L-870,810. Conclusion We report a drug class (other than nucleosidic reverse transcriptase inhibitors) that is capable of inhibiting FIV replication in vitro. The present study helped establish L-870,810, a compound successfully tested in

BRICHOS - a superfamily of multidomain proteins with diverse functions

Directory of Open Access Journals (Sweden)

Johansson Jan

2009-09-01

Full Text Available Abstract Background The BRICHOS domain has been found in 8 protein families with a wide range of functions and a variety of disease associations, such as respiratory distress syndrome, dementia and cancer. The domain itself is thought to have a chaperone function, and indeed three of the families are associated with amyloid formation, but its structure and many of its functional properties are still unknown. Findings The proteins in the BRICHOS superfamily have four regions with distinct properties. We have analysed the BRICHOS proteins focusing on sequence conservation, amino acid residue properties, native disorder and secondary structure predictions. Residue conservation shows large variations between the regions, and the spread of residue conservation between different families can vary greatly within the regions. The secondary structure predictions for the BRICHOS proteins show remarkable coherence even where sequence conservation is low, and there seems to be little native disorder. Conclusions The greatly variant rates of conservation indicates different functional constraints among the regions and among the families. We present three previously unknown BRICHOS families; group A, which may be ancestral to the ITM2 families; group B, which is a close relative to the gastrokine families, and group C, which appears to be a truly novel, disjoint BRICHOS family. The C-terminal region of group C has nearly identical sequences in all species ranging from fish to man and is seemingly unique to this family, indicating critical functional or structural properties.

Structural and Biochemical Investigation of PglF from Campylobacter jejuni Reveals a New Mechanism for a Member of the Short Chain Dehydrogenase/Reductase Superfamily

Energy Technology Data Exchange (ETDEWEB)

Riegert, Alexander S. [Department; Thoden, James B. [Department; Schoenhofen, Ian C. [National; Watson, David C. [National; Young, N. Martin [National; Tipton, Peter A. [Department; Holden, Hazel M. [Department

2017-11-03

Within recent years it has become apparent that protein glycosylation is not limited to eukaryotes. Indeed, in Campylobacter jejuni, a Gram-negative bacterium, more than 60 of its proteins are known to be glycosylated. One of the sugars found in such glycosylated proteins is 2,4-diacetamido-2,4,6-trideoxy-α-d-glucopyranose, hereafter referred to as QuiNAc4NAc. The pathway for its biosynthesis, initiating with UDP-GlcNAc, requires three enzymes referred to as PglF, PglE, and PlgD. The focus of this investigation is on PglF, an NAD+-dependent sugar 4,6-dehydratase known to belong to the short chain dehydrogenase/reductase (SDR) superfamily. Specifically, PglF catalyzes the first step in the pathway, namely, the dehydration of UDP-GlcNAc to UDP-2-acetamido-2,6-dideoxy-α-d-xylo-hexos-4-ulose. Most members of the SDR superfamily contain a characteristic signature sequence of YXXXK where the conserved tyrosine functions as a catalytic acid or a base. Strikingly, in PglF, this residue is a methionine. Here we describe a detailed structural and functional investigation of PglF from C. jejuni. For this investigation five X-ray structures were determined to resolutions of 2.0 Å or better. In addition, kinetic analyses of the wild-type and site-directed variants were performed. On the basis of the data reported herein, a new catalytic mechanism for a SDR superfamily member is proposed that does not require the typically conserved tyrosine residue.

Protein 4.1, a component of the erythrocyte membrane skeleton and its related homologue proteins forming the protein 4.1/FERM superfamily.

Directory of Open Access Journals (Sweden)

Aleksander F Sikorski

2007-01-01

Full Text Available The review is focused on the domain structure and function of protein 4.1, one of the proteins belonging to the membrane skeleton. The protein 4.1 of the red blood cells (4.1R is a multifunctional protein that localizes to the membrane skeleton and stabilizes erythrocyte shape and membrane mechanical properties, such as deformability and stability, via lateral interactions with spectrin, actin, glycophorin C and protein p55. Protein 4.1 binding is modulated through the action of kinases and/or calmodulin-Ca2+. Non-erythroid cells express the 4.1R homologues: 4.1G (general type, 4.1B (brain type, and 4.1N (neuron type, and the whole group belongs to the protein 4.1 superfamily, which is characterized by the presence of a highly conserved FERM domain at the N-terminus of the molecule. Proteins 4.1R, 4.1G, 4.1N and 4.1B are encoded by different genes. Most of the 4.1 superfamily proteins also contain an actin-binding domain. To date, more than 40 members have been identified. They can be divided into five groups: protein 4.1 molecules, ERM proteins, talin-related molecules, protein tyrosine phosphatase (PTPH proteins and NBL4 proteins. We have focused our attention on the main, well known representatives of 4.1 superfamily and tried to choose the proteins which are close to 4.1R or which have distinct functions. 4.1 family proteins are not just linkers between the plasma membrane and membrane skeleton; they also play an important role in various processes. Some, such as focal adhesion kinase (FAK, non-receptor tyrosine kinase that localizes to focal adhesions in adherent cells, play the role in cell adhesion. The other members control or take part in tumor suppression, regulation of cell cycle progression, inhibition of cell proliferation, downstream signaling of the glutamate receptors, and establishment of cell polarity; some are also involved in cell proliferation, cell motility, and/or cell-to-cell communication.

Presence of Foraminifera of Superfamily Komokioidea (Order Astrorhizida) in Colombian deep Caribbean waters.

Science.gov (United States)

Tavera-Martínez, Laura; Marchant, Margarita

2017-10-20

Research regarding deep-sea benthic foraminifera in the Colombian Caribbean requires further development given the complete lack of information related to the different groups that constitute associations and the ecological functions they fulfill. For this purpose, a taxonomic description of Superfamily Komokioidea was composed from macrofauna samples from between 1,215 m and 3,179 m depth, obtained during the research cruise ANH-COL 4 and COL 5 carried out in 2014. Results showed foraminifera belonging to the three families: Komokiidae, Baculellidae, and Normaninidae, inclu-ding five genera (Lana, Komokia, Ipoa, Normaninam, and Catena) and five species (Lana neglecta, Komokia multiramosa, Normanina conferta, Ipoa fragila, and Catena piriformis). This study presents knowledge regarding deep-sea Colombian Caribbean benthic foraminifera, which to date have not been recorded from this region. Their depth distribution when compared with other studies from the Atlantic and Pacific, allows the expansion of taxonomic inventories and the characterization of biodiversity within poorly explored regions.

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, Cindy [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Mueller, Uwe [Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung mbH, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Panjikar, Santosh [European Molecular Biology Laboratory Hamburg, Outstation Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22603 Hamburg (Germany); Sun, Lianli [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China); Ruppert, Martin [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Zhao, Yu [Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China); Stöckigt, Joachim [Department of Pharmaceutical Biology, Institute of Pharmacy, Johannes Gutenberg-University Mainz, Staudinger Weg 5, D-55099 Mainz (Germany); Department of TCM and Natural Drug Research, College of Pharmaceutical Sciences, 513 Zijingang Campus, Zhejiang University, 310058 Hangzhou (China)

2006-12-01

Perakine reductase, a novel member of the aldo-keto reductase enzyme superfamily of higher plants, is involved in the biosynthesis of monoterpenoid indole alkaloids in the Indian medicinal plant Rauvolfia serpentina. The enzyme has been crystallized in C-centered orthorhombic space group and diffracts to 2.0 Å resolution. Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222{sub 1} and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å.

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

International Nuclear Information System (INIS)

Rosenthal, Cindy; Mueller, Uwe; Panjikar, Santosh; Sun, Lianli; Ruppert, Martin; Zhao, Yu; Stöckigt, Joachim

2006-01-01

Perakine reductase, a novel member of the aldo-keto reductase enzyme superfamily of higher plants, is involved in the biosynthesis of monoterpenoid indole alkaloids in the Indian medicinal plant Rauvolfia serpentina. The enzyme has been crystallized in C-centered orthorhombic space group and diffracts to 2.0 Å resolution. Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222 1 and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å

Interactive surface in the PapD chaperone cleft is conserved in pilus chaperone superfamily and essential in subunit recognition and assembly.

OpenAIRE

Slonim, L N; Pinkner, J S; Brändén, C I; Hultgren, S J

1992-01-01

The assembly of adhesive pili in Gram-negative bacteria is modulated by specialized periplasmic chaperone systems. PapD is the prototype member of the superfamily of periplasmic pilus chaperones. Previously, the alignment of chaperone sequences superimposed on the three dimensional structure of PapD revealed the presence of invariant, conserved and variable amino acids. Representative residues that protruded into the PapD cleft were targeted for site directed mutagenesis to investigate the pi...

Mechanism of inhibition of HIV-1 integrase by G-tetrad-forming oligonucleotides in Vitro.

Science.gov (United States)

Jing, N; Marchand, C; Liu, J; Mitra, R; Hogan, M E; Pommier, Y

2000-07-14

The G-tetrad-forming oligonucleotides and have been identified as potent inhibitors of human immunodeficiency virus type 1 integrase (HIV-1 IN) activity (Rando, R. F., Ojwang, J., Elbaggari, A., Reyes, G. R., Tinder, R., McGrath, M. S., and Hogan, M. E. (1995) J. Biol. Chem. 270, 1754-1760; Mazumder, A., Neamati, N., Ojwang, J. O., Sunder, S., Rando, R. F., and Pommier, Y. (1996) Biochemistry 35, 13762-13771; Jing, N., and Hogan, M. E. (1998) J. Biol. Chem. 273, 34992-34999). To understand the inhibition of HIV-1 IN activity by the G-quartet inhibitors, we have designed the oligonucleotides and, composed of three and four G-quartets with stem lengths of 19 and 24 A, respectively. The fact that increasing the G-quartet stem length from 15 to 24 A kept inhibition of HIV-1 IN activity unchanged suggests that the binding interaction occurs between a GTGT loop domain of the G-quartet inhibitors and a catalytic site of HIV-1 IN, referred to as a face-to-face interaction. Docking the NMR structure of (Jing and Hogan (1998)) into the x-ray structure of the core domain of HIV-1 IN, HIV-1 IN-(51-209) (Maignan, S., Guilloteau, J.-P. , Qing, Z.-L., Clement-Mella, C., and Mikol, V. (1998) J. Mol. Biol. 282, 359-368), was performed using the GRAMM program. The statistical distributions of hydrogen bonding between HIV-1 IN and were obtained from the analyses of 1000 random docking structures. The docking results show a high probability of interaction between the GTGT loop residues of the G-quartet inhibitors and the catalytic site of HIV-1 IN, in agreement with the experimental observation.

Risk factors for death in HIV-infected adult African patients receiving anti-retroviral therapy.

Science.gov (United States)

Siika, A M; Wools-Kaloustian, K; Mwangi, A W; Kimaiyo, S N; Diero, L O; Ayuo, P O; Owino-Ong'or, W D; Sidle, J E; Einterz, R M; Yiannoutsos, C T; Musick, B; Tierney, W M

2010-11-01

To determine risk factors for death in HIV-infected African patients on anti-retroviral therapy (ART). Retrospective Case-control study. The MOH-USAID-AMPATH Partnership ambulatory HIV-care clinics in western Kenya. Between November 2001 and December 2005 demographic, clinical and laboratory data from 527 deceased and 1054 living patients receiving ART were compared to determine independent risk factors for death. Median age at ART initiation was 38 versus 36 years for the deceased and living patients respectively (p100/mm3 (HR=1.553. 95% CI (1.156, 2.087), p<0.003). Patients attending rural clinics had threefold higher risk of dying compared to patients attending clinic at a tertiary referral hospital (p<0.0001). Two years after initiating treatment fifty percent of non-adherent patients were alive compared to 75% of adherent patients. Male gender, WHO Stage and haemoglobin level <10 grams% were associated with time to death while age, marital status, educational level, employment status and weight were not. Profoundly immunosuppressed patients were more likely to die early in the course of treatment. Also, patients receiving care in rural clinics were at greater risk of dying than those receiving care in the tertiary referral hospital.

Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein.

Science.gov (United States)

Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena

2014-06-15

Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs. Heterologous NAb titers, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of Ab-binding reactivity revealed preferential recognition of the C1, C2, V2, V3, and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

The S230R Integrase Substitution Associated with Viral Rebound during DTG Monotherapy Confers Low Levels INSTI Drug Resistance.

Science.gov (United States)

Pham, Hanh T; Labrie, Lydia; Wijting, Ingeborg E A; Hassounah, Said; Lok, Ka Yee; Portna, Inna; Goring, Mark; Han, Yingshan; Lungu, Cynthia; van der Ende, Marchina E; Brenner, Bluma G; Boucher, Charles A; Rijnders, Bart J A; van Kampen, Jeroen J A; Mesplède, Thibault; Wainberg, Mark A

2018-03-29

Dolutegravir (DTG) is an integrase strand-transfer inhibitor (INSTI) used for treatment of HIV-infected individuals. Due to its high genetic barrier to resistance, DTG has been clinically investigated as maintenance monotherapy to maintain viral suppression and to reduce complication and healthcare costs. Our study aims to explain the underlying mechanism related to the emergence of a S230R substitution in patients who experienced virological failure while using DTG monotherapy. We evaluated the effect of S230R substitution in regard to IN enzyme activity, viral infectivity, replicative capacity and susceptibility to different INSTIs by biochemical and cell-based assays. S230R substitution conferred 63% reduction in enzyme efficiency. The S230R virus was 1.29-fold less infectious than wildtype (WT), but could replicate in PM1 cells without significant delay. Resistance levels against DTG, CAB, RAL and EVG in tissue culture were 3.85-, 3.72-, 1.52-, and 1.21-fold, respectively. Our data indicate that the S230R substitution is comparable to the previously reported R263K in some respects. Virological failure under DTG monotherapy can occur through the development of such S230R or R263K mutations without the need for high levels DTG resistance.

MP20, the second most abundant lens membrane protein and member of the tetraspanin superfamily, joins the list of ligands of galectin-3

Directory of Open Access Journals (Sweden)

Donaldson Paul J

2001-08-01

Full Text Available Abstract Background Although MP20 is the second most highly expressed membrane protein in the lens its function remains an enigma. Putative functions for MP20 have recently been inferred from its assignment to the tetraspanin superfamily of integral membrane proteins. Members of this family have been shown to be involved in cellular proliferation, differentiation, migration, and adhesion. In this study, we show that MP20 associates with galectin-3, a known adhesion modulator. Results MP20 and galectin-3 co-localized in selected areas of the lens fiber cell plasma membrane. Individually, these proteins purified with apparent molecular masses of 60 kDa and 22 kDa, respectively. A 104 kDa complex was formed in vitro upon mixing the purified proteins. A 102 kDa complex of MP20 and galectin-3 could also be isolated from detergent-solubilized native fiber cell membranes. Binding between MP20 and galectin-3 was disrupted by lactose suggesting the lectin site was involved in the interaction. Conclusions MP20 adds to a growing list of ligands of galectin-3 and appears to be the first representative of the tetraspanin superfamily identified to possess this specificity.

FLT3 ligand preserves the uncommitted CD34+CD38- progenitor cells during cytokine prestimulation for retroviral transduction

DEFF Research Database (Denmark)

Nielsen, S D; Husemoen, L L; Sørensen, T U

2000-01-01

for transduction of CD34+ cells. The effect of cytokine prestimulation on transduction efficiency and the population of uncommitted CD34+CD38- cells was determined. CD34+ cells harvested from umbilical cord blood were kept in suspension cultures and stimulated with combinations of the cytokines stem cell factor......Before stem cell gene therapy can be considered for clinical applications, problems regarding cytokine prestimulation remain to be solved. In this study, a retroviral vector carrying the genes for the enhanced version of green fluorescent protein (EGFP) and neomycin resistance (neo(r)) was used...... in a higher percentage of cells than the EGFP gene, but there seemed to be a positive correlation between expression of the two genes. The effect of cytokine prestimulation was therefore monitored using EGFP as marker for transduction. When SCF was compared to SCF in combination with more potent cytokines...

A long-acting integrase inhibitor protects female macaques from repeated high-dose intravaginal SHIV challenge.

Science.gov (United States)

Andrews, Chasity D; Yueh, Yun Lan; Spreen, William R; St Bernard, Leslie; Boente-Carrera, Mar; Rodriguez, Kristina; Gettie, Agegnehu; Russell-Lodrigue, Kasi; Blanchard, James; Ford, Susan; Mohri, Hiroshi; Cheng-Mayer, Cecilia; Hong, Zhi; Ho, David D; Markowitz, Martin

2015-01-14

Long-acting GSK1265744 (GSK744 LA) is a strand transfer inhibitor of the HIV/SIV (simian immunodeficiency virus) integrase and was shown to be an effective preexposure prophylaxis (PrEP) agent in a low-dose intrarectal SHIV (simian-human immunodeficiency virus) rhesus macaque challenge model. We examined the pharmacokinetics and efficacy of GSK744 LA as PrEP against repeat high-dose intravaginal SHIV challenge in female rhesus macaques treated with Depo-Provera (depot medroxyprogesterone acetate), which promotes viral transmission vaginally. When Depo-Provera-treated female rhesus macaques were dosed with GSK744 LA (50 mg/kg) monthly, systemic and tissue drug concentrations were lower than previously observed in male rhesus macaques. GSK744 concentrations were fivefold lower on average in cervical tissues than in rectal tissues. Eight female rhesus macaques were treated with GSK744 LA at week 0, and four female rhesus macaques served as controls. All animals received a high-dose challenge of SHIV162P3 at week 1. No infection was detected in GSK744 LA-treated rhesus macaques, whereas viremia was detected 1 to 2 weeks after SHIV challenge in all control animals. The GSK744 LA-treated rhesus macaques were given a second administration of drug at week 4 and further challenged at weeks 5 and 7. GSK744 LA treatment protected six of eight female rhesus macaques against three high-dose SHIV challenges, whereas all control animals became infected after the first challenge (P = 0.0003, log-rank test). These results support further clinical development of GSK744 LA for PrEP. Copyright © 2015, American Association for the Advancement of Science.

An Optimized GD2-Targeting Retroviral Cassette for More Potent and Safer Cellular Therapy of Neuroblastoma and Other Cancers.

Directory of Open Access Journals (Sweden)

Simon Thomas

Full Text Available Neuroblastoma is the commonest extra cranial solid cancer of childhood. Despite escalation of treatment regimens, a significant minority of patients die of their disease. Disialoganglioside (GD2 is consistently expressed at high-levels in neuroblastoma tumors, which have been targeted with some success using therapeutic monoclonal antibodies. GD2 is also expressed in a range of other cancer but with the exception of some peripheral nerves is largely absent from non-transformed tissues. Chimeric Antigen Receptors (CARs are artificial type I proteins which graft the specificity of a monoclonal antibody onto a T-cell. Clinical data with early CAR designs directed against GD2 have shown some promise in Neuroblastoma. Here, we describe a GD2-targeting CAR retroviral cassette, which has been optimized for CAR T-cell persistence, efficacy and safety.

Construction and characterization in vitro of a bicistronic retroviral vector coding endostatin and interleukin-2 for use in gene therapy; Construcao e caracterizacao in vitro de um vetor retroviral bicistronico codificando endostatina e interleucina-2 para utilizacao em terapia genica

Energy Technology Data Exchange (ETDEWEB)

Calvo, Fernanda Bernardes

2009-07-01

Gene therapy has been used in preclinical studies and clinical trials in order to alleviate or cure a disease. Retroviral vectors are a tool for gene transfer is widely used. Bicistronic vectors are an attractive alternative for treatment of complex diseases. A variety of options exists to simultaneously express two genes in genetically modified cells. The most common approach relies on bicistronic vectors in which the genes are linked to each other by an internal ribosome entry site allowing co-translational expression of both cistrons. Endostatin, the C-terminal fragment of collagen XVIII, is a potent angiogenesis inhibitor. At present, ES has been widely used in anti-angiogenic in a variety of experimental tumor models, and clinical trials to test it as an anti-tumor agent are already under way. Immunotherapy has been used as adjuvant treatment for tumors and has been used in several preclinical studies and clinical trials. The objective of this project was to construct and characterize 'in vitro' an IRES-based bicistronic retroviral vector encoding endostatin and interleukin-2. The construction of the vector was performed in three stages, the final construction was analyzed by restriction analysis and sequencing. Packaging cells were prepared. The endostatin and interleukin-2 levels were determined by Dot blot. Monocistronic and bicistronic mRNA expression were analyzed by real time RT-PCR. Bicistronic vector showed high levels of virus trites, ranging from 4.20x10{sup 5} to 1.53x10{sup 6}UFC/ml. Secreted levels of endostatin and interleukin-2 ranged from 1.08 to 2.08{mu}g/10{sup 6}cells.24h and 0.66 - 0.89{mu}g/10{sup 6}cells.24h, respectively. The mRNA expression of ES in the NIH3T3 clone pLend-IRES-IL2SN was 2 times higher than the level presented by the NIH3T3 clone pLendSN. The endostatin promoted inhibition (40%) of endothelial cell proliferation. Interleukin-2 promoted a proliferation of 10.6% lymphocytes CD4 and 8.9% of CD8. We conclude that

Identification of the GTPase superfamily in Mycoplasma synoviae and Mycoplasma hyopneumoniae

Directory of Open Access Journals (Sweden)

Clayton Luiz Borges

2007-01-01

Full Text Available Mycoplasmas are the smallest known prokaryotes with self-replication ability. They are obligate parasites, taking up many molecules of their hosts and acting as pathogens in men, animals, birds and plants. Mycoplasma hyopneumoniae is the infective agent of swine mycoplasmosis and Mycoplasma synoviae is responsible for subclinical upper respiratory infections that may result in airsacculitis and synovitis in chickens and turkeys. These highly infectious organisms present a worldwide distribution and are responsible for major economic problems. Proteins of the GTPase superfamily occur in all domains of life, regulating functions such as protein synthesis, cell cycle and differentiation. Despite their functional diversity, all GTPases are believed to have evolved from a single common ancestor. In this work we have identified mycoplasma GTPases by searching the complete genome databases of Mycoplasma synoviae and Mycoplasma hyopneumoniae, J (non-pathogenic and 7448 (pathogenic strains. Fifteen ORFs encoding predicted GTPases were found in M. synoviae and in the two strains of M. hyopneumoniae. Searches for conserved G domains in GTPases were performed and the sequences were classified into families. The GTPase phylogenetic analysis showed that the subfamilies were well resolved into clades. The presence of GTPases in the three strains suggests the importance of GTPases in 'minimalist' genomes.

The Role of Immunoglobulin Superfamily Cell Adhesion Molecules in Cancer Metastasis

Directory of Open Access Journals (Sweden)

Chee Wai Wong

2012-01-01

Full Text Available Metastasis is a major clinical problem and results in a poor prognosis for most cancers. The metastatic pathway describes the process by which cancer cells give rise to a metastatic lesion in a new tissue or organ. It consists of interconnecting steps all of which must be successfully completed to result in a metastasis. Cell-cell adhesion is a key aspect of many of these steps. Adhesion molecules belonging to the immunoglobulin superfamily (Ig-SF commonly play a central role in cell-cell adhesion, and a number of these molecules have been associated with cancer progression and a metastatic phenotype. Surprisingly, the contribution of Ig-SF members to metastasis has not received the attention afforded other cell adhesion molecules (CAMs such as the integrins. Here we examine the steps in the metastatic pathway focusing on how the Ig-SF members, melanoma cell adhesion molecule (MCAM, L1CAM, neural CAM (NCAM, leukocyte CAM (ALCAM, intercellular CAM-1 (ICAM-1 and platelet endothelial CAM-1 (PECAM-1 could play a role. Although much remains to be understood, this review aims to raise the profile of Ig-SF members in metastasis formation and prompt further research that could lead to useful clinical outcomes.

Analysis of the active site mechanism of Tyrosyl-DNA phosphodiesterase I: a member of the phospholipase D superfamily

Science.gov (United States)

Gajewski, Stefan; Comeaux, Evan Q.; Jafari, Nauzanene; Bharatham, Nagakumar; Bashford, Donald; White, Stephen W.; van Waardenburg, Robert C.A.M.

2011-01-01

Tyrosyl DNA phosphodiesterase I (Tdp1) is a member of the phospholipase D superfamily and hydrolyzes 3′phospho-DNA adducts via two conserved catalytic histidines, one acting as the lead nucleophile and the second as a general acid/base. Substitution of the second histidine specifically to arginine contributes to the neurodegenerative disease SCAN1. We investigated the catalytic role of this histidine in the yeast protein (His432) using a combination of X-ray crystallography, biochemistry, yeast genetics and theoretical chemistry. The structures of wild type Tdp1 and His432Arg both show a phosphorylated form of the nucleophilic histidine that is not observed in the structure of His432Asn. The phosphohistidine is stabilized in the His432Arg structure by the guanidinium group that also restricts access of a nucleophilic water molecule to the Tdp1-DNA intermediate. Biochemical analyses confirm that His432Arg forms an observable and unique Tdp1-DNA adduct during catalysis. Substitution of His432 by Lys does not affect catalytic activity or yeast phenotype, but substitution with Asn, Gln, Leu, Ala, Ser and Thr all result in severely compromised enzymes and Top1-camptothecin dependent lethality. Surprisingly, His432Asn did not show a stable covalent Tdp1-DNA intermediate which suggests another catalytic defect. Theoretical calculations revealed that the defect resides in the nucleophilic histidine and that the pKa of this histidine is crucially dependent upon the second histidine and the incoming phosphate of the substrate. This represents a unique example of substrate-activated catalysis that applies to the entire phospholipase D superfamily. PMID:22155078

Perinatal genotoxicity and carcinogenicity of anti-retroviral nucleoside analog drugs

International Nuclear Information System (INIS)

Poirier, Miriam C.; Olivero, Ofelia A.; Walker, Dale M.; Walker, Vernon E.

2004-01-01

The current worldwide spread of the human immunodeficiency virus-1 (HIV-1) to the heterosexual population has resulted in approximately 800 000 children born yearly to HIV-1-infected mothers. In the absence of anti-retroviral intervention, about 25% of the approximately 7000 children born yearly to HIV-1-infected women in the United States are HIV-1 infected. Administration of zidovudine (AZT) prophylaxis during pregnancy reduces the rate of infant HIV-1 infection to approximately 7%, and further reductions are achieved with the addition of lamivudine (3TC) in the clinical formulation Combivir. Whereas clinically this is a remarkable achievement, AZT and 3TC are DNA replication chain terminators known to induce various types of genotoxicity. Studies in rodents have demonstrated AZT-DNA incorporation, HPRT mutagenesis, telomere shortening, and tumorigenicity in organs of fetal mice exposed transplacentally to AZT. In monkeys, both AZT and 3TC become incorporated into the DNA from multiple fetal organs taken at birth after administration of human-equivalent protocols to pregnant dams during gestation, and telomere shortening has been found in monkey fetuses exposed to both drugs. In human infants, AZT-DNA and 3TC-DNA incorporation as well as HPRT and GPA mutagenesis have been documented in cord blood from infants exposed in utero to Combivir. In infants of mice, monkeys, and humans, levels of AZT-DNA incorporation were remarkably similar, and in newborn mice and humans, mutation frequencies were also very similar. Given the risk-benefit ratio, these highly successful drugs will continue to be used for prevention of vertical viral transmission, however evidence of genotoxicity in mouse and monkey models and in the infants themselves would suggest that exposed children should be followed well past adolescence for early detection of potential cancer hazard

Genome-wide identification and analysis of the B3 superfamily of transcription factors in Brassicaceae and major crop plants.

Science.gov (United States)

Peng, Fred Y; Weselake, Randall J

2013-05-01

The plant-specific B3 superfamily of transcription factors has diverse functions in plant growth and development. Using a genome-wide domain analysis, we identified 92, 187, 58, 90, 81, 55, and 77 B3 transcription factor genes in the sequenced genome of Arabidopsis, Brassica rapa, castor bean (Ricinus communis), cocoa (Theobroma cacao), soybean (Glycine max), maize (Zea mays), and rice (Oryza sativa), respectively. The B3 superfamily has substantially expanded during the evolution in eudicots particularly in Brassicaceae, as compared to monocots in the analysis. We observed domain duplication in some of these B3 proteins, forming more complex domain architectures than currently understood. We found that the length of B3 domains exhibits a large variation, which may affect their exact number of α-helices and β-sheets in the core structure of B3 domains, and possibly have functional implications. Analysis of the public microarray data indicated that most of the B3 gene pairs encoding Arabidopsis-rice orthologs are preferentially expressed in different tissues, suggesting their different roles in these two species. Using ESTs in crops, we identified many B3 genes preferentially expressed in reproductive tissues. In a sequence-based quantitative trait loci analysis in rice and maize, we have found many B3 genes associated with traits such as grain yield, seed weight and number, and protein content. Our results provide a framework for future studies into the function of B3 genes in different phases of plant development, especially the ones related to traits in major crops.

Anti-inflammatory and vasoprotective activity of a retroviral-derived peptide, homologous to human endogenous retroviruses: endothelial cell effects.

Directory of Open Access Journals (Sweden)

George J Cianciolo

Full Text Available Malignant and inflammatory tissues sometimes express endogenous retroviruses or their proteins. A highly-conserved sequence from retroviral transmembrane (TM proteins, termed the "immunosuppressive domain (ID", is associated with inhibition of immune and inflammatory functions. An octadecapeptide (MN10021 from the ID of retroviral TM protein p15E inhibits in vitro release of pro-inflammatory cytokines and increases synthesis of anti-inflammatory IL-10. We sought to determine if MN10021 has significant in vivo effects. MN10021, prepared by solid-phase synthesis, was dimerized through a naturally-occurring, carboxy-terminal cysteine. In vivo anti-inflammatory activity was determined using a murine model of sodium periodate (NaIO(4-induced peritonitis. In vivo vasoprotective effects were determined using: (1 a carrageenan-induced model of disseminated intravascular coagulation (DIC in mice; (2 a reverse passive Arthus model in guinea pigs; and (3 vasoregulatory effects in spontaneously hypertensive rats (SHR. In vitro studies included: (1 binding/uptake of MN10021 using human monocytes, cultured fibroblasts, and vascular endothelial cells (VEC; (2 gene expression by RT-PCR of MN10021-treated VEC; and (3 apoptosis of MN10021-treated VEC exposed to staurosporine or TNF-α. One-tenth nmol MN10021 inhibits 50 percent of the inflammatory response in the mouse peritonitis model. Furthermore, 73 nmol MN10021 completely protects mice in a lethal model of carrageenan-induced DIC and inhibits vascular leak in both the mouse DIC model and a guinea pig reverse passive Arthus reaction. MN10021 binds to and is taken up in a specific manner by both human monocytes and VEC but not by cultured human fibroblasts. Surprisingly, orally-administered MN10021 lowers blood pressure in SHR rats by 10-15% within 1 h suggesting a direct or indirect effect on the vascular endothelium. MN10021 and derived octapeptides induce iNOS (inducible nitric oxide synthase mRNA in VEC

Characterization of putative multidrug resistance transporters of the major facilitator-superfamily expressed in Salmonella Typhi

DEFF Research Database (Denmark)

Shaheen, Aqsa; Ismat, Fouzia; Iqbal, Mazhar

2015-01-01

Multidrug resistance mediated by efflux pumps is a well-known phenomenon in infectious bacteria. Although much work has been carried out to characterize multidrug efflux pumps in Gram-negative and Gram-positive bacteria, such information is still lacking for many deadly pathogens. The aim...... of this study was to gain insight into the substrate specificity of previously uncharacterized transporters of Salmonella Typhi to identify their role in the development of multidrug resistance. S. Typhi genes encoding putative members of the major facilitator superfamily were cloned and expressed in the drug......-hypersensitive Escherichia coli strain KAM42, and tested for transport of 25 antibacterial compounds, including representative antibiotics of various classes, antiseptics, dyes and detergents. Of the 15 tested putative transporters, STY0901, STY2458 and STY4874 exhibited a drug-resistance phenotype. Among these, STY4874...

L-Chicoric acid inhibits human immunodeficiency virus type 1 integration in vivo and is a noncompetitive but reversible inhibitor of HIV-1 integrase in vitro

International Nuclear Information System (INIS)

Reinke, Ryan A.; Lee, Deborah J.; McDougall, Brenda R.; King, Peter J.; Victoria, Joseph; Mao Yingqun; Lei Xiangyang; Reinecke, Manfred G.; Robinson, W. Edward

2004-01-01

The human immunodeficiency virus (HIV) integrase (IN) must covalently join the viral cDNA into a host chromosome for productive HIV infection. L-Chicoric acid (L-CA) enters cells poorly but is a potent inhibitor of IN in vitro. Using quantitative real-time polymerase chain reaction (PCR), L-CA inhibits integration at concentrations from 500 nM to 10 μM but also inhibits entry at concentrations above 1 μM. Using recombinant HIV IN, steady-state kinetic analyses with L-CA were consistent with a noncompetitive or irreversible mechanism of inhibition. IN, in the presence or absence of L-CA, was successively washed. Inhibition of IN diminished, demonstrating that L-CA was reversibly bound to the protein. These data demonstrate that L-CA is a noncompetitive but reversible inhibitor of IN in vitro and of HIV integration in vivo. Thus, L-CA likely interacts with amino acids other than those which bind substrate

Metagenomic analysis of lysogeny in Tampa Bay: implications for prophage gene expression.

Directory of Open Access Journals (Sweden)

Lauren McDaniel

Full Text Available Phage integrase genes often play a role in the establishment of lysogeny in temperate phage by catalyzing the integration of the phage into one of the host's replicons. To investigate temperate phage gene expression, an induced viral metagenome from Tampa Bay was sequenced by 454/Pyrosequencing. The sequencing yielded 294,068 reads with 6.6% identifiable. One hundred-three sequences had significant similarity to integrases by BLASTX analysis (e < or =0.001. Four sequences with strongest amino-acid level similarity to integrases were selected and real-time PCR primers and probes were designed. Initial testing with microbial fraction DNA from Tampa Bay revealed 1.9 x 10(7, and 1300 gene copies of Vibrio-like integrase and Oceanicola-like integrase L(-1 respectively. The other two integrases were not detected. The integrase assay was then tested on microbial fraction RNA extracted from 200 ml of Tampa Bay water sampled biweekly over a 12 month time series. Vibrio-like integrase gene expression was detected in three samples, with estimated copy numbers of 2.4-1280 L(-1. Clostridium-like integrase gene expression was detected in 6 samples, with estimated copy numbers of 37 to 265 L(-1. In all cases, detection of integrase gene expression corresponded to the occurrence of lysogeny as detected by prophage induction. Investigation of the environmental distribution of the two expressed integrases in the Global Ocean Survey Database found the Vibrio-like integrase was present in genome equivalents of 3.14% of microbial libraries and all four viral metagenomes. There were two similar genes in the library from British Columbia and one similar gene was detected in both the Gulf of Mexico and Sargasso Sea libraries. In contrast, in the Arctic library eleven similar genes were observed. The Clostridium-like integrase was less prevalent, being found in 0.58% of the microbial and none of the viral libraries. These results underscore the value of metagenomic data

Phi Class of Glutathione S-transferase Gene Superfamily Widely Exists in Nonplant Taxonomic Groups.

Science.gov (United States)

Munyampundu, Jean-Pierre; Xu, You-Ping; Cai, Xin-Zhong

2016-01-01

Glutathione S-transferases (GSTs) constitute a superfamily of enzymes involved in detoxification of noxious compounds and protection against oxidative damage. GST class Phi (GSTF), one of the important classes of plant GSTs, has long been considered as plant specific but was recently found in basidiomycete fungi. However, the range of nonplant taxonomic groups containing GSTFs remains unknown. In this study, the distribution and phylogenetic relationships of nonplant GSTFs were investigated. We identified GSTFs in ascomycete fungi, myxobacteria, and protists Naegleria gruberi and Aureococcus anophagefferens. GSTF occurrence in these bacteria and protists correlated with their genome sizes and habitats. While this link was missing across ascomycetes, the distribution and abundance of GSTFs among ascomycete genomes could be associated with their lifestyles to some extent. Sequence comparison, gene structure, and phylogenetic analyses indicated divergence among nonplant GSTFs, suggesting polyphyletic origins during evolution. Furthermore, in silico prediction of functional partners suggested functional diversification among nonplant GSTFs.

Transcription Profiling Demonstrates Epigenetic Control of Non-retroviral RNA Virus-Derived Elements in the Human Genome

Directory of Open Access Journals (Sweden)

Kozue Sofuku

2015-09-01

Full Text Available Endogenous bornavirus-like nucleoprotein elements (EBLNs are DNA sequences in vertebrate genomes formed by the retrotransposon-mediated integration of ancient bornavirus sequence. Thus, EBLNs evidence a mechanism of retrotransposon-mediated RNA-to-DNA information flow from environment to animals. Although EBLNs are non-transposable, they share some features with retrotransposons. Here, to test whether hosts control the expression of EBLNs similarly to retrotransposons, we profiled the transcription of all Homo sapiens EBLNs (hsEBLN-1 to hsEBLN-7. We could detect transcription of all hsEBLNs in at least one tissue. Among them, hsEBLN-1 is transcribed almost exclusively in the testis. In most tissues, expression from the hsEBLN-1 locus is silenced epigenetically. Finally, we showed the possibility that hsEBLN-1 integration at this locus affects the expression of a neighboring gene. Our results suggest that hosts regulate the expression of endogenous non-retroviral virus elements similarly to how they regulate the expression of retrotransposons, possibly contributing to new transcripts and regulatory complexity to the human genome.

Genetic modification of hematopoietic cells using retroviral and lentiviral vectors: safety considerations for vector design and delivery into target cells.

Science.gov (United States)

Dropulic, Boro

2005-07-01

The recent development of leukemia in three patients following retroviral vector gene transfer in hematopoietic stem cells, resulting in the death of one patient, has raised safety concerns for the use of integrating gene transfer vectors for human gene therapy. This review discusses these serious adverse events from the perspective of whether restrictions on vector design and vector-modified target cells are warranted at this time. A case is made against presently establishing specific restrictions for vector design and transduced cells; rather, their safety should be ascertained by empiric evaluation in appropriate preclinical models on a case-by-case basis. Such preclinical data, coupled with proper informed patient consent and a risk-benefit ratio analysis, provide the best available prospective evaluation of gene transfer vectors prior to their translation into the clinic.

Microbial biodegradation of biuret: defining biuret hydrolases within the isochorismatase superfamily.

Science.gov (United States)

Robinson, Serina L; Badalamenti, Jonathan P; Dodge, Anthony G; Tassoulas, Lambros J; Wackett, Lawrence P

2018-03-12

Biuret is a minor component of urea fertilizer and an intermediate in s-triazine herbicide biodegradation. The microbial metabolism of biuret has never been comprehensively studied. Here, we enriched and isolated bacteria from a potato field that grew on biuret as a sole nitrogen source. We sequenced the genome of the fastest-growing isolate, Herbaspirillum sp. BH-1 and identified genes encoding putative biuret hydrolases (BHs). We purified and characterized a functional BH enzyme from Herbaspirillum sp. BH-1 and two other bacteria from divergent phyla. The BH enzymes reacted exclusively with biuret in the range of 2-11 µmol min -1 mg -1 protein. We then constructed a global protein superfamily network to map structure-function relationships in the BH subfamily and used this to mine > 7000 genomes. High-confidence BH sequences were detected in Actinobacteria, Alpha- and Beta-proteobacteria, and some fungi, archaea and green algae, but not animals or land plants. Unexpectedly, no cyanuric acid hydrolase homologs were detected in > 90% of genomes with BH homologs, suggesting BHs may have arisen independently of s-triazine ring metabolism. This work links genotype to phenotype by enabling accurate genome-mining to predict microbial utilization of biuret. Importantly, it advances understanding of the microbial capacity for biuret biodegradation in agricultural systems. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

A novel inhibitor of α9α10 nicotinic acetylcholine receptors from Conus vexillum delineates a new conotoxin superfamily.

Directory of Open Access Journals (Sweden)

Sulan Luo

Full Text Available Conotoxins (CTxs selectively target a range of ion channels and receptors, making them widely used tools for probing nervous system function. Conotoxins have been previously grouped into superfamilies according to signal sequence and into families based on their cysteine framework and biological target. Here we describe the cloning and characterization of a new conotoxin, from Conus vexillum, named αB-conotoxin VxXXIVA. The peptide does not belong to any previously described conotoxin superfamily and its arrangement of Cys residues is unique among conopeptides. Moreover, in contrast to previously characterized conopeptide toxins, which are expressed initially as prepropeptide precursors with a signal sequence, a ''pro'' region, and the toxin-encoding region, the precursor sequence of αB-VxXXIVA lacks a ''pro'' region. The predicted 40-residue mature peptide, which contains four Cys, was synthesized in each of the three possible disulfide arrangements. Investigation of the mechanism of action of αB-VxXXIVA revealed that the peptide is a nicotinic acetylcholine receptor (nAChR antagonist with greatest potency against the α9α10 subtype. (1H nuclear magnetic resonance (NMR spectra indicated that all three αB-VxXXIVA isomers were poorly structured in aqueous solution. This was consistent with circular dichroism (CD results which showed that the peptides were unstructured in buffer, but adopted partially helical conformations in aqueous trifluoroethanol (TFE solution. The α9α10 nAChR is an important target for the development of analgesics and cancer chemotherapeutics, and αB-VxXXIVA represents a novel ligand with which to probe the structure and function of this protein.

Genetic polymorphisms in glutathione S-transferase (GST) superfamily and arsenic metabolism in residents of the Red River Delta, Vietnam

International Nuclear Information System (INIS)

Agusa, Tetsuro; Iwata, Hisato; Fujihara, Junko; Kunito, Takashi; Takeshita, Haruo; Tu Binh Minh; Pham Thi Kim Trang; Pham Hung Viet; Tanabe, Shinsuke

2010-01-01

To elucidate the role of genetic factors in arsenic metabolism, we investigated associations of genetic polymorphisms in the members of glutathione S-transferase (GST) superfamily with the arsenic concentrations in hair and urine, and urinary arsenic profile in residents in the Red River Delta, Vietnam. Genotyping was conducted for GST ω1 (GSTO1) Ala140Asp, Glu155del, Glu208Lys, Thr217Asn, and Ala236Val, GST ω2 (GSTO2) Asn142Asp, GST π1 (GSTP1) Ile105Val, GST μ1 (GSTM1) wild/null, and GST θ1 (GSTT1) wild/null. There were no mutation alleles for GSTO1 Glu208Lys, Thr217Asn, and Ala236Val in this population. GSTO1 Glu155del hetero type showed higher urinary concentration of As V than the wild homo type. Higher percentage of DMA V in urine of GSTM1 wild type was observed compared with that of the null type. Strong correlations between GSTP1 Ile105Val and arsenic exposure level and profile were observed in this study. Especially, heterozygote of GSTP1 Ile105Val had a higher metabolic capacity from inorganic arsenic to monomethyl arsenic, while the opposite trend was observed for ability of metabolism from As V to As III . Furthermore, other factors including sex, age, body mass index, arsenic level in drinking water, and genotypes of As (+ 3 oxidation state) methyltransferase (AS3MT) were also significantly co-associated with arsenic level and profile in the Vietnamese. To our knowledge, this is the first study indicating the associations of genetic factors of GST superfamily with arsenic metabolism in a Vietnamese population.

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

Science.gov (United States)

Knuschke, Torben; Rotan, Olga; Bayer, Wibke; Kollenda, Sebastian; Dickow, Julia; Sutter, Kathrin; Hansen, Wiebke; Dittmer, Ulf; Lang, Karl S.; Epple, Matthias; Buer, Jan; Westendorf, Astrid M.

2018-01-01

T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP) nanoparticle (NP)-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I) are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL) and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/−) or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections. PMID:29740425

Mycobacterium smegmatis SftH exemplifies a distinctive clade of superfamily II DNA-dependent ATPases with 3′ to 5′ translocase and helicase activities

OpenAIRE

Yakovleva, Lyudmila; Shuman, Stewart

2012-01-01

Bacterial DNA helicases are nucleic acid-dependent NTPases that play important roles in DNA replication, recombination and repair. We are interested in the DNA helicases of Mycobacteria, a genus of the phylum Actinobacteria, which includes the human pathogen Mycobacterium tuberculosis and its avirulent relative Mycobacterium smegmatis. Here, we identify and characterize M. smegmatis SftH, a superfamily II helicase with a distinctive domain structure, comprising an N-terminal NTPase domain and...

Clinical Improvement by Switching to an Integrase Strand Transfer Inhibitor in Hemophiliac Patients with HIV: The Japan Cohort Study of HIV Patients Infected through Blood Products.

Science.gov (United States)

Kawado, Miyuki; Hashimoto, Shuji; Oka, Shin-Ichi; Fukutake, Katsuyuki; Higasa, Satoshi; Yatsuhashi, Hiroshi; Ogane, Miwa; Okamoto, Manabu; Shirasaka, Takuma

2017-01-01

This study aimed to determine improvement in HIV RNA levels and the CD4 cell count by switching to an antiretroviral regimen with an integrase strand transfer inhibitor (INSTI) in patients with HIV. This study was conducted on Japanese patients with HIV who were infected by blood products in the 1980s. Data were collected between 2007 and 2014. Data of 564 male hemophiliac patients with HIV from the Japan Cohort Study of HIV Patients Infected through Blood Products were available. Changes in antiretroviral regimen use, HIV RNA levels, and the CD4 cell count between 2007 and 2014 were examined. From 2007 to 2014, the proportion of use of a regimen with an INSTI increased from 0.0% to 41.0%. For patients with HIV who used a regimen, including an INSTI, the proportion of HIV RNA levels products. This suggests that performing this switch in clinical practice will lead to favorable effects.

Endogenous Retroviral Insertions Indicate a Secondary Introduction of Domestic Sheep Lineages to the Caucasus and Central Asia between the Bronze and Iron Age

Science.gov (United States)

Schroeder, Oskar; Benecke, Norbert; Frölich, Kai; Peng, Zuogang; Kaniuth, Kai; Sverchkov, Leonid; Reinhold, Sabine; Belinskiy, Andrey; Ludwig, Arne

2017-01-01

Sheep were one of the first livestock species domesticated by humans. After initial domestication in the Middle East they were spread across Eurasia. The modern distribution of endogenous Jaagsiekte sheep retrovirus insertions in domestic sheep breeds suggests that over the course of millennia, successive introductions of improved lineages and selection for wool quality occurred in the Mediterranean region and most of Asia. Here we present a novel ancient DNA approach using data of endogenous retroviral insertions in Bronze and Iron Age domestic sheep from the Caucasus and Pamir mountain areas. Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia. PMID:28632161

Endogenous Retroviral Insertions Indicate a Secondary Introduction of Domestic Sheep Lineages to the Caucasus and Central Asia between the Bronze and Iron Age

Directory of Open Access Journals (Sweden)

Oskar Schroeder

2017-06-01

Full Text Available Sheep were one of the first livestock species domesticated by humans. After initial domestication in the Middle East they were spread across Eurasia. The modern distribution of endogenous Jaagsiekte sheep retrovirus insertions in domestic sheep breeds suggests that over the course of millennia, successive introductions of improved lineages and selection for wool quality occurred in the Mediterranean region and most of Asia. Here we present a novel ancient DNA approach using data of endogenous retroviral insertions in Bronze and Iron Age domestic sheep from the Caucasus and Pamir mountain areas. Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia.

A unique uracil-DNA binding protein of the uracil DNA glycosylase superfamily.

Science.gov (United States)

Sang, Pau Biak; Srinath, Thiruneelakantan; Patil, Aravind Goud; Woo, Eui-Jeon; Varshney, Umesh

2015-09-30

Uracil DNA glycosylases (UDGs) are an important group of DNA repair enzymes, which pioneer the base excision repair pathway by recognizing and excising uracil from DNA. Based on two short conserved sequences (motifs A and B), UDGs have been classified into six families. Here we report a novel UDG, UdgX, from Mycobacterium smegmatis and other organisms. UdgX specifically recognizes uracil in DNA, forms a tight complex stable to sodium dodecyl sulphate, 2-mercaptoethanol, urea and heat treatment, and shows no detectable uracil excision. UdgX shares highest homology to family 4 UDGs possessing Fe-S cluster. UdgX possesses a conserved sequence, KRRIH, which forms a flexible loop playing an important role in its activity. Mutations of H in the KRRIH sequence to S, G, A or Q lead to gain of uracil excision activity in MsmUdgX, establishing it as a novel member of the UDG superfamily. Our observations suggest that UdgX marks the uracil-DNA for its repair by a RecA dependent process. Finally, we observed that the tight binding activity of UdgX is useful in detecting uracils in the genomes. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

The Microbiota and Abundance of the Class 1 Integron-Integrase Gene in Tropical Sewage Treatment Plant Influent and Activated Sludge.

Directory of Open Access Journals (Sweden)

Magna C Paiva

Full Text Available Bacteria are assumed to efficiently remove organic pollutants from sewage in sewage treatment plants, where antibiotic-resistance genes can move between species via mobile genetic elements known as integrons. Nevertheless, few studies have addressed bacterial diversity and class 1 integron abundance in tropical sewage. Here, we describe the extant microbiota, using V6 tag sequencing, and quantify the class 1 integron-integrase gene (intI1 in raw sewage (RS and activated sludge (AS. The analysis of 1,174,486 quality-filtered reads obtained from RS and AS samples revealed complex and distinct bacterial diversity in these samples. The RS sample, with 3,074 operational taxonomic units, exhibited the highest alpha-diversity indices. Among the 25 phyla, Proteobacteria, Bacteroidetes and Firmicutes represented 85% (AS and 92% (RS of all reads. Increased relative abundance of Micrococcales, Myxococcales, and Sphingobacteriales and reduced pathogen abundance were noted in AS. At the genus level, differences were observed for the dominant genera Simplicispira and Diaphorobacter (AS as well as for Enhydrobacter (RS. The activated sludge process decreased (55% the amount of bacteria harboring the intI1 gene in the RS sample. Altogether, our results emphasize the importance of biological treatment for diminishing pathogenic bacteria and those bearing the intI1 gene that arrive at a sewage treatment plant.

Suplementação de N-acetilcisteína em pacientes infectados pelo HIV submetidos ao primeiro tratamento anti-retroviral: Avaliação do efeito sobre a carga viral, TNF-α, IL-6, IL-8, β2-microglobulina, IgA, IgG e IgM, haptoglobina e α1-glicoproteína ácida N-acetylcysteine supplementation of HIV-infected patients under the first anti-retroviral treatment: Evaluation of the effect on viral load, TNF-α, IL-6, IL-8, β2-microglobulin, IgA, IgG, IgM, haptoglobin and α1-acid glycoprotein

Directory of Open Access Journals (Sweden)

Aricio Treitinger

2002-03-01

Full Text Available Indivíduos infectados pelo vírus da imunodeficiência humana (HIV- 1 apresentam aumento progressivo da carga viral, da destruição do sistema de defesa imune celular e alterações imunológicas e inflamatórias, incluindo a elevação dos níveis séricos do fator de necrose tumoral alfa (TNF-α, interleucina 8 (IL-8, β2- microglobulina, IgA, IgG e IgM, haptoglobina e α1-glicoproteína ácida.O objetivo deste estudo foi avaliar os níveis séricos destes marcadores em indivíduos submetidos ao primeiro tratamento antiretroviral, suplementados ou não com N-acetilcisteína. Participaram deste estudo, duplo cego controlado por placebo, que teve a duração de 180 dias, 24 indivíduos que iniciaram a terapia antiretroviral O Grupo Estudo foi constituído por 11 indivíduos, que receberam suplementação de 600 mg/dia de Nacetilcisteína enquanto o Grupo Controle foi constituído por 13 indivíduo que receberam placebo. Os níveis dos marcadores avaliados foram determinados no dia anterior ao início do tratamento a que foram submetidos e após 60, 120 e 180 dias. Verificou-se diminuição significativa dos níveis de TNF-α (p=0,0001, IL-6 (p>0,05, IL-8 (p=0,0001, β2-microglobulina (p=0,0005, IgA (p=0,007, IgG (p=0,001, IgM (p=0,0001, haptoglobina (p=0,0001 e α1-glicoproteína ácida (p=0.012 em decorrência do tratamento anti-retroviral. A suplementação com N-acetilcisteína, na dose utilizada neste estudo, não teve efeitos aditivos ou sinérgicos sobre as variáveis analisadas. Em conclusão, a suplementação de pacientes HIV-positivos com 600 mg/dia de N-acetilcisteína não proporcionou benefícios adicionais àqueles decorrentes do tratamento anti-retroviral.Human immunodeficiency virus infection is associated with a progressive elevation of viral load and with a continuous destruction of the immune cellular defense system which is marked by immunological and inflammatory disorders characteristic of HIV-infected individuals. These

Induction of Type I Interferons by Therapeutic Nanoparticle-Based Vaccination Is Indispensable to Reinforce Cytotoxic CD8+ T Cell Responses During Chronic Retroviral Infection

Directory of Open Access Journals (Sweden)

Torben Knuschke

2018-04-01

Full Text Available T cell dysfunction and immunosuppression are characteristic for chronic viral infections and contribute to viral persistence. Overcoming these burdens is the goal of new therapeutic strategies to cure chronic infectious diseases. We recently described that therapeutic vaccination of chronic retrovirus infected mice with a calcium phosphate (CaP nanoparticle (NP-based vaccine carrier, functionalized with CpG and viral peptides is able to efficiently reactivate the CD8+ T cell response and improve the eradication of virus infected cells. However, the mechanisms underlying this effect were largely unclear. While type I interferons (IFNs I are considered to drive T cell exhaustion by persistent immune activation during chronic viral infection, we here describe an indispensable role of IFN I induced by therapeutic vaccination to efficiently reinforce cytotoxic CD8+ T cells (CTL and improve control of chronic retroviral infection. The induction of IFN I is CpG dependent and leads to significant IFN signaling indicated by upregulation of IFN stimulated genes. By vaccinating chronically retrovirus-infected mice lacking the IFN I receptor (IFNAR−/− or by blocking IFN I signaling in vivo during therapeutic vaccination, we demonstrate that IFN I signaling is necessary to drive full reactivation of CTLs. Surprisingly, we also identified an impaired suppressive capability of regulatory T cells in the presence of IFNα, which implicates an important role for vaccine-induced IFNα in the regulation of the T cell response during chronic retroviral infection. Our data suggest that inducing IFN I signaling in conjunction with the presentation of viral antigens can reactivate immune functions and reduce viral loads in chronic infections. Therefore, we propose CaP NPs as potential therapeutic tool to treat chronic infections.

Molecular and Functional Characterization of Mouse S5D-SRCRB: A New Group B Member of the Scavenger Receptor Cysteine-Rich Superfamily

DEFF Research Database (Denmark)

Miró-Julià, Cristina; Roselló, Sandra; Martínez, Vanesa G

2011-01-01

The scavenger receptor cysteine-rich superfamily (SRCR-SF) members are transmembrane and/or secreted receptors exhibiting one or several repeats of a cysteine-rich protein module of ∼100 aa, named scavenger receptor cysteine-rich (SRCR). Two types of SRCR domains (A or B) have been reported, which...... differ in the number of coding exons and intradomain cysteines. Although no unifying function has been reported for SRCR-SF members, recognition of pathogen-associated molecular patterns (PAMPs) was recently shown for some of them. In this article, we report the structural and functional characterization...

Construction and characterization in vitro of a bicistronic retroviral vector coding endostatin and interleukin-2 for use in gene therapy

International Nuclear Information System (INIS)

Calvo, Fernanda Bernardes

2009-01-01

Gene therapy has been used in preclinical studies and clinical trials in order to alleviate or cure a disease. Retroviral vectors are a tool for gene transfer is widely used. Bicistronic vectors are an attractive alternative for treatment of complex diseases. A variety of options exists to simultaneously express two genes in genetically modified cells. The most common approach relies on bicistronic vectors in which the genes are linked to each other by an internal ribosome entry site allowing co-translational expression of both cistrons. Endostatin, the C-terminal fragment of collagen XVIII, is a potent angiogenesis inhibitor. At present, ES has been widely used in anti-angiogenic in a variety of experimental tumor models, and clinical trials to test it as an anti-tumor agent are already under way. Immunotherapy has been used as adjuvant treatment for tumors and has been used in several preclinical studies and clinical trials. The objective of this project was to construct and characterize 'in vitro' an IRES-based bicistronic retroviral vector encoding endostatin and interleukin-2. The construction of the vector was performed in three stages, the final construction was analyzed by restriction analysis and sequencing. Packaging cells were prepared. The endostatin and interleukin-2 levels were determined by Dot blot. Monocistronic and bicistronic mRNA expression were analyzed by real time RT-PCR. Bicistronic vector showed high levels of virus trites, ranging from 4.20x10 5 to 1.53x10 6 UFC/ml. Secreted levels of endostatin and interleukin-2 ranged from 1.08 to 2.08μg/10 6 cells.24h and 0.66 - 0.89μg/10 6 cells.24h, respectively. The mRNA expression of ES in the NIH3T3 clone pLend-IRES-IL2SN was 2 times higher than the level presented by the NIH3T3 clone pLendSN. The endostatin promoted inhibition (40%) of endothelial cell proliferation. Interleukin-2 promoted a proliferation of 10.6% lymphocytes CD4 and 8.9% of CD8. We conclude that the IRES bicistronic vector

Production of glycosylated physiologically normal human α1-antitrypsin by mouse fibroblasts modified by insertion of a human α1-antitrypsin cDNA using a retroviral vector

International Nuclear Information System (INIS)

Garver, R.I. Jr.; Chytil, A.; Karlsson, S.

1987-01-01

α 2 -Antitrypsin (α 1 AT) deficiency is a hereditary disorder characterized by reduced serum levels of α 1 AT, resulting in destruction of the lower respiratory tract by neutrophil elastase. As an approach to augment α 1 AT levels in this disorder with physiologically normal human α 1 AT, the authors have integrated a full-length normal human α 1 AT cDNA into the genome of mouse fibroblasts. To accomplish this, the retroviral vector N2 was modified by inserting the simian virus 40 early promoter followed by the α 1 AT cDNA. Southern analysis demonstrated that the intact cDNA was present in the genome of selected clones of the transfected murine fibroblasts psi2 and infected NIH 3T3. The clones produced three mRNA transcripts containing human α 1 AT sequences, secreted an α 1 AT molecule recognized by an anti-human α 1 AT antibody, with the same molecular mass as normal human α 1 AT and that complexed with and inhibited human neutrophil elastase. The psi2 produced α 1 AT was glycosylated, and when infused intravenously into mice, it had a serum half-life similar to normal α 1 AT purified from human plasma and markedly longer than that of nonglycosylated human α 1 AT cDNA-directed yeast-produced α 1 AT. These studies demonstrate the feasibility of using a retroviral vector to insert the normal human α 1 AT cDNA into non-α 1 AT-producing cells, resulting in the synthesis and secretion of physiologically normal α 1 AT

Cost-effectiveness of anti-retroviral therapy at a district hospital in southern Ethiopia

Directory of Open Access Journals (Sweden)

Robberstad Bjarne

2009-07-01

Full Text Available Abstract Background As the resource implications of expanding anti-retroviral therapy (ART are likely to be large, there is a need to explore its cost-effectiveness. So far, there is no such information available from Ethiopia. Objective To assess the cost-effectiveness of ART for routine clinical practice in a district hospital setting in Ethiopia. Methods We estimated the unit cost of HIV-related care from the 2004/5 fiscal year expenditure of Arba Minch Hospital in southern Ethiopia. We estimated outpatient and inpatient service use from HIV-infected patients who received care and treatment at the hospital between January 2003 and March 2006. We measured the health effect as life years gained (LYG for patients receiving ART compared with those not receiving such treatment. The study adopted a health care provider perspective and included both direct and overhead costs. We used Markov model to estimate the lifetime costs, health benefits and cost-effectiveness of ART. Findings ART yielded an undiscounted 9.4 years expected survival, and resulted in 7.1 extra LYG compared to patients not receiving ART. The lifetime incremental cost is US$2,215 and the undiscounted incremental cost per LYG is US$314. When discounted at 3%, the additional LYG decreases to 5.5 years and the incremental cost per LYG increases to US$325. Conclusion The undiscounted and discounted incremental costs per LYG from introducing ART were less than the per capita GDP threshold at the base year. Thus, ART could be regarded as cost-effective in a district hospital setting in Ethiopia.

Increasing the effectiveness of hematopoiesis in myelodysplastic syndromes: erythropoiesis-stimulating agents and transforming growth factor-β superfamily inhibitors.

Science.gov (United States)

Mies, Anna; Platzbecker, Uwe

2017-07-01

Patients with lower-risk myelodysplastic syndromes (MDS) are mainly affected by chronic anemia and fatigue. Treatment strategies aim to improve anemia and quality of life, as well as iron overload due to red blood cell transfusion support. To promote proliferation and differentiation of erythropoiesis, erythropoiesis-stimulating agents (ESAs) such as erythropoietin (EPO) and mimetics are applied as first-line therapy in a large fraction of lower-risk MDS patients. In general, ESAs yield favorable responses in about half of the patients, although responses are often short-lived. In fact, many ESA-refractory patients harbor defects in late-stage erythropoiesis downstream of EPO action. Novel transforming growth factor (TGF)-β superfamily inhibitors sotatercept and luspatercept represent a promising approach to alleviate anemia by stimulating erythroid differentiation. Copyright © 2017 Elsevier Inc. All rights reserved.

RECEPTOR SUPERFAMILY OF TUMOR NECROSIS FACTOR Α, AND HSP90 HEAT SHOCK PROTEIN: A MOLECULAR BASIS FOR INTERACTIONS

Directory of Open Access Journals (Sweden)

N. V. Ryazantseva

2011-01-01

Full Text Available Abstract.  A  study  was  performed  aiming  to  investigate  interactions  between  TNFα  receptor  (TNF1 superfamily and heat shock protein Hsp90, using a Jurkat tumor cell line. The tumor cells cultured in presence of Hsp90 inhibitor (17-AAG showed increased numbers of cells, presenting surface TNFR1 and FasR, which facilitate  triggering  of  programmed  cell  death.  It  was  also  revealed  that  Hsp90  blockage  under  the  in  vitro conditions causes a decrease in FasL, while not affecting TNFα and sTNFR1 production by the tumor cells. (Med. Immunol., 2011, vol. 13, N 2-3, pp 247-252 

Who is accessing public-sector anti-retroviral treatment in the Free State, South Africa? An exploratory study of the first three years of programme implementation

Directory of Open Access Journals (Sweden)

Booysen Frederik

2010-07-01

Full Text Available Abstract Background Although South Africa has the largest public-sector anti-retroviral treatment (ART programme in the world, anti-retroviral coverage in adults was only 40.2% in 2008. However, longitudinal studies of who is accessing the South African public-sector ART programme are scarce. This study therefore had one main research question: who is accessing public-sector ART in the Free State Province, South Africa? The study aimed to extend the current literature by investigating, in a quantitative manner and using a longitudinal study design, the participants enrolled in the public-sector ART programme in the period 2004-2006 in the Free State Province of South Africa. Methods Differences in the demographic (age, sex, population group and marital status socio-economic (education, income, neo-material indicators, geographic (travel costs, relocation for ART, and medical characteristics (CD4, viral load, time since first diagnosis, treatment status among 912 patients enrolled in the Free State public-sector ART programme between 2004 and 2006 were assessed with one-way analysis of variance, Bonferroni post-hoc analysis, and cross tabulations with the chi square test. Results The patients accessing treatment tended to be female (71.1% and unemployed (83.4%. However, although relatively poor, those most likely to access ART services were not the most impoverished patients. The proportion of female patients increased (P P P P P Conclusions Our analysis showed significant changes in the demographic, socio-economic, geographic, and medical characteristics of the patients during the first three years of the programme. Knowledge of the characteristics of these patients can assist policy makers in developing measures to retain them in care. The information reported here can also be usefully applied to target patient groups that are currently not reached in the implementation of the ART programme.

Relative Stabilities of Conserved and Non-Conserved Structures in the OB-Fold Superfamily

Directory of Open Access Journals (Sweden)

Andrei T. Alexandrescu

2009-05-01

Full Text Available The OB-fold is a diverse structure superfamily based on a β-barrel motif that is often supplemented with additional non-conserved secondary structures. Previous deletion mutagenesis and NMR hydrogen exchange studies of three OB-fold proteins showed that the structural stabilities of sites within the conserved β-barrels were larger than sites in non-conserved segments. In this work we examined a database of 80 representative domain structures currently classified as OB-folds, to establish the basis of this effect. Residue-specific values were obtained for the number of Cα-Cα distance contacts, sequence hydrophobicities, crystallographic B-factors, and theoretical B-factors calculated from a Gaussian Network Model. All four parameters point to a larger average flexibility for the non-conserved structures compared to the conserved β-barrels. The theoretical B-factors and contact densities show the highest sensitivity.Our results suggest a model of protein structure evolution in which novel structural features develop at the periphery of conserved motifs. Core residues are more resistant to structural changes during evolution since their substitution would disrupt a larger number of interactions. Similar factors are likely to account for the differences in stability to unfolding between conserved and non-conserved structures.

Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea

Directory of Open Access Journals (Sweden)

Harshavardhanan Vijayakumar

2016-07-01

Full Text Available Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18 are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS. Currently, understanding of their function(s during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT and cold susceptible (CS lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants.

Phylogenetic comparison of F-Box (FBX gene superfamily within the plant kingdom reveals divergent evolutionary histories indicative of genomic drift.

Directory of Open Access Journals (Sweden)

Zhihua Hua

Full Text Available The emergence of multigene families has been hypothesized as a major contributor to the evolution of complex traits and speciation. To help understand how such multigene families arose and diverged during plant evolution, we examined the phylogenetic relationships of F-Box (FBX genes, one of the largest and most polymorphic superfamilies known in the plant kingdom. FBX proteins comprise the target recognition subunit of SCF-type ubiquitin-protein ligases, where they individually recruit specific substrates for ubiquitylation. Through the extensive analysis of 10,811 FBX loci from 18 plant species, ranging from the alga Chlamydomonas reinhardtii to numerous monocots and eudicots, we discovered strikingly diverse evolutionary histories. The number of FBX loci varies widely and appears independent of the growth habit and life cycle of land plants, with a little as 198 predicted for Carica papaya to as many as 1350 predicted for Arabidopsis lyrata. This number differs substantially even among closely related species, with evidence for extensive gains/losses. Despite this extraordinary inter-species variation, one subset of FBX genes was conserved among most species examined. Together with evidence of strong purifying selection and expression, the ligases synthesized from these conserved loci likely direct essential ubiquitylation events. Another subset was much more lineage specific, showed more relaxed purifying selection, and was enriched in loci with little or no evidence of expression, suggesting that they either control more limited, species-specific processes or arose from genomic drift and thus may provide reservoirs for evolutionary innovation. Numerous FBX loci were also predicted to be pseudogenes with their numbers tightly correlated with the total number of FBX genes in each species. Taken together, it appears that the FBX superfamily has independently undergone substantial birth/death in many plant lineages, with its size and rapid

Isolation and functional analysis of Thmfs1, the first major facilitator superfamily transporter from the biocontrol fungus Trichoderma harzianum.

Science.gov (United States)

Liu, Mu; Liu, Jun; Wang, Wei Min

2012-10-01

A novel major facilitator superfamily (MFS) transporter gene, Thmfs1, was isolated from Trichoderma harzianum (T. harzianum). A Thmfs1 over-expressing mutant displayed enhanced antifungal activity and fungicide tolerance, while the Thmfs1 disruption mutant showed the opposite trend. Trichodermin production in Thmfs1 disruption group (185 mg l(-1)) was decreased by less than 17 % compared to the parental strain, suggesting that Thmfs1 is not mainly responsible for trichodermin secretion. Real-time PCR showed that Thmfs1 transcript level could be induced by a certain range of trichodermin concentrations, while expression of Tri5, encoding a trichodiene synthase, was strongly inhibited under these conditions. To our knowledge, Thmfs1 is the first MFS transporter gene identified in T. harzianum.

The ΦBT1 large serine recombinase catalyzes DNA integration at pseudo-attB sites in the genus Nocardia

Directory of Open Access Journals (Sweden)

Marion Herisse

2018-05-01

Full Text Available Plasmid vectors based on bacteriophage integrases are important tools in molecular microbiology for the introduction of foreign DNA, especially into bacterial species where other systems for genetic manipulation are limited. Site specific integrases catalyze recombination between phage and bacterial attachment sites (attP and attB, respectively and the best studied integrases in the actinomycetes are the serine integrases from the Streptomyces bacteriophages ΦC31 and ΦBT1. As this reaction is unidirectional and highly stable, vectors containing phage integrase systems have been used in a number of genetic engineering applications. Plasmids bearing the ΦBT1 integrase have been used to introduce DNA into Streptomyces and Amycolatopsis strains; however, they have not been widely studied in other actinobacterial genera. Here, we show that vectors based on ΦBT1 integrase can stably integrate into the chromosomes of a range of Nocardia species, and that this integration occurs despite the absence of canonical attB sites in these genomes. Furthermore, we show that a ΦBT1 integrase-based vector can insert at multiple pseudo-attB sites within a single strain and we determine the sequence of a pseudo-attB motif. These data suggest that ΦBT1 integrase-based vectors can be used to readily and semi-randomly introduce foreign DNA into the genomes of a range of Nocardia species. However, the precise site of insertion will likely require empirical determination in each species to avoid unexpected off-target effects.

The host cell sulfonation pathway contributes to retroviral infection at a step coincident with provirus establishment.

Directory of Open Access Journals (Sweden)

James W Bruce

2008-11-01

Full Text Available The early steps of retrovirus replication leading up to provirus establishment are highly dependent on cellular processes and represent a time when the virus is particularly vulnerable to antivirals and host defense mechanisms. However, the roles played by cellular factors are only partially understood. To identify cellular processes that participate in these critical steps, we employed a high volume screening of insertionally mutagenized somatic cells using a murine leukemia virus (MLV vector. This approach identified a role for 3'-phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1, one of two enzymes that synthesize PAPS, the high energy sulfate donor used in all sulfonation reactions catalyzed by cellular sulfotransferases. The role of the cellular sulfonation pathway was confirmed using chemical inhibitors of PAPS synthases and cellular sulfotransferases. The requirement for sulfonation was mapped to a stage during or shortly after MLV provirus establishment and influenced subsequent gene expression from the viral long terminal repeat (LTR promoter. Infection of cells by an HIV vector was also shown to be highly dependent on the cellular sulfonation pathway. These studies have uncovered a heretofore unknown regulatory step of retroviral replication, have defined a new biological function for sulfonation in nuclear gene expression, and provide a potentially valuable new target for HIV/AIDS therapy.

The endogenous retroviral locus ERVWE1 is a bona fide gene involved in hominoid placental physiology

Science.gov (United States)

Mallet, François; Bouton, Olivier; Prudhomme, Sarah; Cheynet, Valérie; Oriol, Guy; Bonnaud, Bertrand; Lucotte, Gérard; Duret, Laurent; Mandrand, Bernard

2004-01-01

The definitive demonstration of a role for a recently acquired gene is a difficult task, requiring exhaustive genetic investigations and functional analysis. The situation is indeed much more complicated when facing multicopy gene families, because most or portions of the gene are conserved among the hundred copies of the family. This is the case for the ERVWE1 locus of the human endogenous retrovirus W family (HERV-W), which encodes an envelope glycoprotein (syncytin) likely involved in trophoblast differentiation. Here we describe, in 155 individuals, the positional conservation of this locus and the preservation of the envelope ORF. Sequencing of the critical elements of the ERVWE1 provirus showed a striking conservation among the 48 alleles of 24 individuals, including the LTR elements involved in the transcriptional machinery, the splice sites involved in the maturation of subgenomic Env mRNA, and the Env ORF. The functionality and tissue specificity of the 5′ LTR were demonstrated, as well as the fusogenic activity of the envelope polymorphic variants. Such functions were also shown to be preserved in the orthologous loci isolated from chimpanzee, gorilla, orangutan, and gibbon. This functional preservation among humans and during evolution strongly argued for the involvement of this recently acquired retroviral envelope glycoprotein in hominoid placental physiology. PMID:14757826

Another cat and mouse game: Deciphering the evolution of the SCGB superfamily and exploring the molecular similarity of major cat allergen Fel d 1 and mouse ABP using computational approaches.

Science.gov (United States)

Durairaj, Rajesh; Pageat, Patrick; Bienboire-Frosini, Cécile

2018-01-01

The mammalian secretoglobin (SCGB) superfamily contains functionally diverse members, among which the major cat allergen Fel d 1 and mouse salivary androgen-binding protein (ABP) display similar subunits. We searched for molecular similarities between Fel d 1 and ABP to examine the possibility that they play similar roles. We aimed to i) cluster the evolutionary relationships of the SCGB superfamily; ii) identify divergence patterns, structural overlap, and protein-protein docking between Fel d 1 and ABP dimers; and iii) explore the residual interaction between ABP dimers and steroid binding in chemical communication using computational approaches. We also report that the evolutionary tree of the SCGB superfamily comprises seven unique palm-like clusters, showing the evolutionary pattern and divergence time tree of Fel d 1 with 28 ABP paralogs. Three ABP subunits (A27, BG27, and BG26) share phylogenetic relationships with Fel d 1 chains. The Fel d 1 and ABP subunits show similarities in terms of sequence conservation, identical motifs and binding site clefts. Topologically equivalent positions were visualized through superimposition of ABP A27:BG27 (AB) and ABP A27:BG26 (AG) dimers on a heterodimeric Fel d 1 model. In docking, Fel d 1-ABP dimers exhibit the maximum surface binding ability of AG compared with that of AB dimers and the several polar interactions between ABP dimers with steroids. Hence, cat Fel d 1 is an ABP-like molecule in which monomeric chains 1 and 2 are the equivalent of the ABPA and ABPBG monomers, respectively. These findings suggest that the biological and molecular function of Fel d 1 is similar to that of ABP in chemical communication, possibly via pheromone and/or steroid binding.

Another cat and mouse game: Deciphering the evolution of the SCGB superfamily and exploring the molecular similarity of major cat allergen Fel d 1 and mouse ABP using computational approaches

Science.gov (United States)

Pageat, Patrick; Bienboire-Frosini, Cécile

2018-01-01

The mammalian secretoglobin (SCGB) superfamily contains functionally diverse members, among which the major cat allergen Fel d 1 and mouse salivary androgen-binding protein (ABP) display similar subunits. We searched for molecular similarities between Fel d 1 and ABP to examine the possibility that they play similar roles. We aimed to i) cluster the evolutionary relationships of the SCGB superfamily; ii) identify divergence patterns, structural overlap, and protein-protein docking between Fel d 1 and ABP dimers; and iii) explore the residual interaction between ABP dimers and steroid binding in chemical communication using computational approaches. We also report that the evolutionary tree of the SCGB superfamily comprises seven unique palm-like clusters, showing the evolutionary pattern and divergence time tree of Fel d 1 with 28 ABP paralogs. Three ABP subunits (A27, BG27, and BG26) share phylogenetic relationships with Fel d 1 chains. The Fel d 1 and ABP subunits show similarities in terms of sequence conservation, identical motifs and binding site clefts. Topologically equivalent positions were visualized through superimposition of ABP A27:BG27 (AB) and ABP A27:BG26 (AG) dimers on a heterodimeric Fel d 1 model. In docking, Fel d 1-ABP dimers exhibit the maximum surface binding ability of AG compared with that of AB dimers and the several polar interactions between ABP dimers with steroids. Hence, cat Fel d 1 is an ABP-like molecule in which monomeric chains 1 and 2 are the equivalent of the ABPA and ABPBG monomers, respectively. These findings suggest that the biological and molecular function of Fel d 1 is similar to that of ABP in chemical communication, possibly via pheromone and/or steroid binding. PMID:29771985

Efficient generation of fully reprogrammed human iPS cells via polycistronic retroviral vector and a new cocktail of chemical compounds.

Directory of Open Access Journals (Sweden)

Zhonghui Zhang

Full Text Available Direct reprogramming of human somatic cells into induced pluripotent stem (iPS cells by defined transcription factors (TFs provides great potential for regenerative medicine and biomedical research. This procedure has many challenges, including low reprogramming efficiency, many partially reprogrammed colonies, somatic coding mutations in the genome, etc. Here, we describe a simple approach for generating fully reprogrammed human iPS cells by using a single polycistronic retroviral vector expressing four human TFs in a single open reading frame (ORF, combined with a cocktail containing three small molecules (Sodium butyrate, SB431542, and PD0325901. Our results demonstrate that human iPS cells generated by this approach express human ES cells markers and exhibit pluripotency demonstrated by their abilities to differentiate into the three germ layers in vitro and in vivo. Notably, this approach not only provides a much faster reprogramming process but also significantly diminishes partially reprogrammed iPS cell colonies, thus facilitating efficient isolation of desired fully reprogrammed iPS cell colonies.

Specific in vitro cleavage of Mason-Pfizer monkey virus capsid protein: evidence for a potential role of retroviral protease in early stages of infection

International Nuclear Information System (INIS)

Rumlova, Michaela; Ruml, Tomas; Pohl, Jan; Pichova, Iva

2003-01-01

Processing of Gag polyproteins by viral protease (PR) leads to reorganization of immature retroviral particles and formation of a ribonucleoprotein core. In some retroviruses, such as HIV and RSV, cleavage of a spacer peptide separating capsid and nucleocapsid proteins is essential for the core formation. We show here that no similar spacer peptide is present in the capsid-nucleocapsid (CA-NC) region of Mason-Pfizer monkey virus (M-PMV) and that the CA protein is cleaved in vitro by the PR within the major homology region (MHR) and the NC protein in several sites at the N-terminus. The CA cleavage product was also identified shortly after penetration of M-PMV into COS cells, suggesting that the protease-catalyzed cleavage is involved in core disintegration

The 1.8-Å resolution crystal structure of YDR533Cp from Saccharomyces cerevisiae: A member of the DJ-1/ThiJ/PfpI superfamily

Science.gov (United States)

Wilson, Mark A.; Amour, Courtney V. St.; Collins, Jennifer L.; Ringe, Dagmar; Petsko, Gregory A.

2004-01-01

The yeast gene YDR533C encodes a protein belonging to the DJ-1/ThiJ/PfpI superfamily. This family includes the human protein DJ-1, which is mutated in autosomal recessive early-onset Parkinson's disease. The function of DJ-1 and its yeast homologue YDR533Cp is unknown. We report here the crystal structure of YDR533Cp at 1.8-Å resolution. The structure indicates that the closest relative to YDR533Cp is the Escherichia coli heat shock protein Hsp31 (YedU), which has both chaperone and protease activity. As expected, the overall fold of the core domain of YDR533Cp is also similar to that of DJ-1 and the bacterial protease PfpI. YDR533Cp contains a possible catalytic triad analogous to that of Hsp31 and an additional domain that is present in Hsp31 but is not seen in DJ-1 and other members of the family. The cysteine in this triad (Cys-138) is oxidized in this crystal structure, similar to modifications seen in the corresponding cysteine in the crystal structure of DJ-1. YDR533Cp appears to be a dimer both in solution and the crystal, but this dimer is formed by a different interface than that found in Hsp31 or other members of the superfamily. PMID:14745011

Dolutegravir versus placebo in subjects harbouring HIV-1 with integrase inhibitor resistance associated substitutions: 48-week results from VIKING-4, a randomized study.

Science.gov (United States)

Akil, Bisher; Blick, Gary; Hagins, Debbie P; Ramgopal, Moti N; Richmond, Gary J; Samuel, Rafik M; Givens, Naomi; Vavro, Cindy; Song, Ivy H; Wynne, Brian; Ait-Khaled, Mounir

2015-01-01

The Phase III VIKING-3 study demonstrated that dolutegravir (DTG) 50 mg twice daily was efficacious in antiretroviral therapy (ART)-experienced subjects harbouring raltegravir- and/or elvitegravir-resistant HIV-1. VIKING-4 (ING116529) included a placebo-controlled 7-day monotherapy phase to demonstrate that short-term antiviral activity was attributable to DTG. VIKING-4 is a Phase III randomized, double-blind study in therapy-experienced adults with integrase inhibitor (INI)-resistant virus randomized to DTG 50 mg twice daily or placebo while continuing their failing regimen (without raltegravir or elvitegravir) for 7 days (clinicaltrials.gov identifier NCT01568892). At day 8, all subjects switched to open-label DTG 50 mg twice daily and optimized background therapy including ≥1 fully active drug. The primary end point was change from baseline in plasma HIV-1 RNA at day 8. The study population (n=30) was highly ART-experienced with advanced HIV disease. Patients had extensive baseline resistance to all approved antiretroviral classes. Adjusted mean change in HIV-1 RNA at day 8 was 
-1.06 log10 copies/ml for the DTG arm and 0.10 log10 copies/ml for the placebo arm (treatment difference -1.16 log10 copies/ml [-1.52, -0.80]; PVIKING-3 study.

Detection of integrase in retroviral particles by a specific DNA sensor with a potential for adaptation to point-of-care diagnosis

DEFF Research Database (Denmark)

Wang, Jing

might be controlled by rational drug development and combination therapy. Early detection of HIV-positive individuals has a direct impact on therapeutic efficacy and can therefore reduce the risk of transmission. With regard to the disadvantage of the current routine HIV screening, it is therefore...

Outcomes of human immunodeficiency virus-infected children after anti-retroviral therapy in Malaysia.

Science.gov (United States)

Moy, Fong Siew; Fahey, Paul; Nik Yusoff, Nik K; Razali, Kamarul A; Nallusamy, Revathy

2015-02-01

To describe outcome and examine factors associated with mortality among human immunodeficiency virus (HIV)-infected children in Malaysia after anti-retroviral therapy (ART). Retrospective and prospective data collected through March 2009 from children in four different states in Malaysia enrolled in TREAT Asia's Pediatric HIV Observational Database were analysed. Of 347 children in the cohort, only 278 (80.1%) were commenced on ART. The median CD4 count and median age at baseline prior to ART was 272 cells/μL and 4.2 years (interquartile range (IQR): 1.4, 7.4 years), respectively. The median duration of follow-up was 3.7 years (IQR: 1.8, 6.0) with 32 deaths giving a crude mortality rate of 2.86 per 100 child-years. The mortality rate highest in the first 6 months of ART was 10.62 per 100 child-years and declined to 1.83 per 100 child-years thereafter. On univariate analyses, only baseline median CD4 percentage, weight for age z score, height for age z score and anaemia were significantly associated with mortality. Upon including all four of these predictors into a single multivariate model, only weight for age z score remained statistically significantly predictive of mortality. Children commenced on ART had high mortality in the first 6 months especially in those with low CD4 percentage, wasting and anaemia. Poor nutritional status is an important independent predictor of mortality in this study. Besides initiating ART therapy, nutritional support and intervention must receive the utmost attention. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Anti-retroviral therapy fails to restore the severe Th-17: Tc-17 imbalance observed in peripheral blood during simian immunodeficiency virus infection.

Science.gov (United States)

Kader, M; Bixler, S; Piatak, M; Lifson, J; Mattapallil, J J

2009-10-01

Human immuno deficiency virus and simian immunodeficiency virus infections are characterized by a severe loss of Th-17 cells (IL-17(+)CD4(+) T cells) that has been associated with disease progression and systemic dissemination of bacterial infections. Anti-retroviral therapy (ART) has led to repopulation of CD4(+) T cells in peripheral tissues with little sustainable repopulation in mucosal tissues. Given the central importance of Th-17 cells in mucosal homeostasis, it is not known if the failure of ART to permanently repopulate mucosal tissues is associated with a failure to restore Th-17 cells that are lost during infection. Dynamics of alpha4(+)beta7(hi) CD4(+) T cells in peripheral blood of SIV infected rhesus macaques were evaluated and compared to animals that were treated with ART. The frequency of Th-17 and Tc-17 cells was determined following infection and after therapy. Relative expression of IL-21, IL-23, and TGFbeta was determined using Taqman PCR. Treatment of SIV infected rhesus macaques with anti-retroviral therapy was associated with a substantial repopulation of mucosal homing alpha4(+)beta7(hi)CD4(+) T cells in peripheral blood. This repopulation, however, was not accompanied by a restoration of Th-17 responses. Interestingly, SIV infection was associated with an increase in Tc-17 responses (IL-17(+)CD8(+) T cells) suggesting to a skewing in the ratio of Th-17: Tc-17 cells from a predominantly Th-17 phenotype to a predominantly Tc-17 phenotype. Surprisingly, Tc-17 responses remained high during the course of therapy suggesting that ART failed to correct the imbalance in Th-17 : Tc-17 responses induced following SIV infection. ART was associated with substantial repopulation of alpha4(+)beta7(hi) CD4(+) T cells in peripheral blood with little or no rebound of Th-17 cells. On the other hand, repopulation of alpha4(+)beta7(hi) CD4(+) T cells was accompanied by persistence of high levels of Tc-17 cells in peripheral blood. The dysregulation of Th-17

Retroviral DNA--the silent winner: blood transfusion containing latent feline leukemia provirus causes infection and disease in naïve recipient cats.

Science.gov (United States)

Nesina, Stefanie; Katrin Helfer-Hungerbuehler, A; Riond, Barbara; Boretti, Felicitas S; Willi, Barbara; Meli, Marina L; Grest, Paula; Hofmann-Lehmann, Regina

2015-12-21

veterinary medicine, such as the requirement for testing blood donors and blood products for FeLV provirus by sensitive polymerase chain reaction, but are also of general interest by revealing the importance of latent retroviral DNA in infected hosts. When aiming to eliminate a retroviral infection from a population, provirus carriers must be considered.

The major facilitator superfamily transporter Knq1p modulates boron homeostasis in Kluyveromyces lactis.

Science.gov (United States)

Svrbicka, Alexandra; Toth Hervay, Nora; Gbelska, Yvetta

2016-03-01

Boron is an essential micronutrient for living cells, yet its excess causes toxicity. To date, the mechanisms of boron toxicity are poorly understood. Recently, the ScATR1 gene has been identified encoding the main boron efflux pump in Saccharomyces cerevisiae. In this study, we analyzed the ScATR1 ortholog in Kluyveromyces lactis--the KNQ1 gene, to understand whether it participates in boron stress tolerance. We found that the KNQ1 gene, encoding a permease belonging to the major facilitator superfamily, is required for K. lactis boron tolerance. Deletion of the KNQ1 gene led to boron sensitivity and its overexpression increased K. lactis boron tolerance. The KNQ1 expression was induced by boron and the intracellular boron concentration was controlled by Knq1p. The KNQ1 promoter contains two putative binding motifs for the AP-1-like transcription factor KlYap1p playing a central role in oxidative stress defense. Our results indicate that the induction of the KNQ1 expression requires the presence of KlYap1p and that Knq1p like its ortholog ScAtr1p in S. cerevisiae functions as a boron efflux pump providing boron resistance in K. lactis.

Characterization of the complete mitochondrial genome of Marshallagia marshalli and phylogenetic implications for the superfamily Trichostrongyloidea.

Science.gov (United States)

Sun, Miao-Miao; Han, Liang; Zhang, Fu-Kai; Zhou, Dong-Hui; Wang, Shu-Qing; Ma, Jun; Zhu, Xing-Quan; Liu, Guo-Hua

2018-01-01

Marshallagia marshalli (Nematoda: Trichostrongylidae) infection can lead to serious parasitic gastroenteritis in sheep, goat, and wild ruminant, causing significant socioeconomic losses worldwide. Up to now, the study concerning the molecular biology of M. marshalli is limited. Herein, we sequenced the complete mitochondrial (mt) genome of M. marshalli and examined its phylogenetic relationship with selected members of the superfamily Trichostrongyloidea using Bayesian inference (BI) based on concatenated mt amino acid sequence datasets. The complete mt genome sequence of M. marshalli is 13,891 bp, including 12 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. All protein-coding genes are transcribed in the same direction. Phylogenetic analyses based on concatenated amino acid sequences of the 12 protein-coding genes supported the monophylies of the families Haemonchidae, Molineidae, and Dictyocaulidae with strong statistical support, but rejected the monophyly of the family Trichostrongylidae. The determination of the complete mt genome sequence of M. marshalli provides novel genetic markers for studying the systematics, population genetics, and molecular epidemiology of M. marshalli and its congeners.

Multi point of care instrument evaluation for use in anti-retroviral clinics in South Africa.

Science.gov (United States)

Gounden, Verena; George, Jaya

2012-01-01

South Africa has the largest prevalence of HIV infected individuals in the world. The introduction of point of care testing to anti-retroviral (ARV) clinic sites is hoped to fast track initiation of patients on ARVs and to allow for earlier recognition of adverse effects such as dyslipidaemia, renal and hepatic dysfunction. We evaluated six instruments for the following analytes: glucose, lactate, creatinine, cholesterol, triglycerides, HDL-cholesterol, alanine transaminase (ALT), and glycated haemoglobin. Comparisons with the central laboratory analyser were performed as well as precision studies. A scoring system was developed by the authors to evaluate the instruments in terms of analytical performance, cost, ease of use, and other operational characteristics. As one of the goals of the placement of these instruments was that their operation was simple enough to be used by non-laboratory staff, ease of use contributed a large proportion to the final scoring. Analytical performance of the POC analysers were generally similar, however, there were significant differences in operational characteristics and ease of use. Bias for the different analytes when compared to the laboratory analyser ranged from -27% to 14%. Calculated total errors for all analytes except for HDL cholesterol were within total allowable error recommendations. The two instruments (Roche Reflotron and Cholestech LDX) with the highest overall total points achieved the highest scores for ease of use. This pilot study has led to the development of a scoring system for the evaluation of POC instruments.

Antibody against Microbial Neuraminidases Recognizes Human Sialidase 3 (NEU3: the Neuraminidase/Sialidase Superfamily Revisited

Directory of Open Access Journals (Sweden)

Chiguang Feng

2017-06-01

Full Text Available Neuraminidases (NAs are critical virulence factors for several microbial pathogens. With a highly conserved catalytic domain, a microbial NA “superfamily” has been proposed. We previously reported that murine polymorphonuclear leukocyte (PMN sialidase activity was important in leukocyte trafficking to inflamed sites and that antibodies to Clostridium perfringens NA recognized a cell surface molecule(s, presumed to be a sialidase of eukaryotic origin on interleukin-8-stimulated human and murine PMNs. These antibodies also inhibited cell sialidase activity both in vitro and, in the latter instance, in vivo. We therefore hypothesized that mammalian sialidases share structural homology and epitopes with microbial NAs. We now report that antibodies to one of the isoforms of C. perfringens NA, as well as anti-influenza virus NA serum, recognize human NEU3 but not NEU1 and that antibodies to C. perfringens NA inhibit NEU3 enzymatic activity. We conclude that the previously described microbial NA superfamily extends to human sialidases. Strategies designed to therapeutically inhibit microbial NA may need to consider potential compromising effects on human sialidases, particularly those expressed in cells of the immune system.

"Every drug goes to treat its own disease…" - a qualitative study of perceptions and experiences of taking anti-retrovirals concomitantly with anti-malarials among those affected by HIV and malaria in Tanzania

DEFF Research Database (Denmark)

Mangesho, Peter E; Reynolds, Joanna; Lemnge, Martha

2014-01-01

BACKGROUND: Little is known about how people living with human immunodeficiency virus (HIV) experience malaria and the concomitant use of anti-malarial treatments with anti-retrovirals (ARVs). An understanding of how patients make sense of these experiences is important to consider in planning......, perceptions of drug strength appeared to compel some people not enrolled in the clinical study to take the drugs at separate times to avoid anticipated harm to the body. CONCLUSIONS: Management of HIV and malaria concurrently often requires individuals to cross the domains of different disease programmes...

Solution structure and phylogenetics of Prod1, a member of the three-finger protein superfamily implicated in salamander limb regeneration.

Directory of Open Access Journals (Sweden)

Acely Garza-Garcia

Full Text Available BACKGROUND: Following the amputation of a limb, newts and salamanders have the capability to regenerate the lost tissues via a complex process that takes place at the site of injury. Initially these cells undergo dedifferentiation to a state competent to regenerate the missing limb structures. Crucially, dedifferentiated cells have memory of their level of origin along the proximodistal (PD axis of the limb, a property known as positional identity. Notophthalmus viridescens Prod1 is a cell-surface molecule of the three-finger protein (TFP superfamily involved in the specification of newt limb PD identity. The TFP superfamily is a highly diverse group of metazoan proteins that includes snake venom toxins, mammalian transmembrane receptors and miscellaneous signaling molecules. METHODOLOGY/PRINCIPAL FINDINGS: With the aim of identifying potential orthologs of Prod1, we have solved its 3D structure and compared it to other known TFPs using phylogenetic techniques. The analysis shows that TFP 3D structures group in different categories according to function. Prod1 clusters with other cell surface protein TFP domains including the complement regulator CD59 and the C-terminal domain of urokinase-type plasminogen activator. To infer orthology, a structure-based multiple sequence alignment of representative TFP family members was built and analyzed by phylogenetic methods. Prod1 has been proposed to be the salamander CD59 but our analysis fails to support this association. Prod1 is not a good match for any of the TFP families present in mammals and this result was further supported by the identification of the putative orthologs of both CD59 and N. viridescens Prod1 in sequence data for the salamander Ambystoma tigrinum. CONCLUSIONS/SIGNIFICANCE: The available data suggest that Prod1, and thereby its role in encoding PD identity, is restricted to salamanders. The lack of comparable limb-regenerative capability in other adult vertebrates could be

An activation domain within the walleye dermal sarcoma virus retroviral cyclin protein is essential for inhibition of the viral promoter

International Nuclear Information System (INIS)

Rovnak, Joel; Hronek, Brett W.; Ryan, Sean O.; Cai, Sumin; Quackenbush, Sandra L.

2005-01-01

Walleye dermal sarcoma virus (WDSV) is a complex retrovirus associated with seasonal dermal sarcomas. Developing tumors have low levels of accessory gene transcripts, A1 and B, and regressing tumors have high levels of full-length and spliced transcripts. Transcript A1 encodes a retroviral cyclin (rv-cyclin) with limited homology to host cyclins. The rv-cyclin is physically linked to components of the transcriptional co-activator complex, Mediator, and regulates transcription. In walleye fibroblasts, it inhibits the WDSV promoter independently of cis-acting DNA sequences. The rv-cyclin activates transcription from GAL4 promoters when fused to the GAL4 DNA binding domain. A 30 a.a. activation domain in the carboxy region can be inactivated by single point mutations, and these mutations diminish the ability of the rv-cyclin to inhibit the WDSV promoter. When fused to glutathione S-transferase, the rv-cyclin, its carboxy region, and the activation domain pull down components of transcription complexes from nuclear extracts, and pulldown is lost by mutation of the activation domain

Development of elvitegravir resistance and linkage of integrase inhibitor mutations with protease and reverse transcriptase resistance mutations.

Directory of Open Access Journals (Sweden)

Mark A Winters

Full Text Available Failure of antiretroviral regimens containing elvitegravir (EVG and raltegravir (RAL can result in the appearance of integrase inhibitor (INI drug-resistance mutations (DRMs. While several INI DRMs have been identified, the evolution of EVG DRMs and the linkage of these DRMs with protease inhibitor (PI and reverse transcriptase inhibitor (RTI DRMs have not been studied at the clonal level. We examined the development of INI DRMs in 10 patients failing EVG-containing regimens over time, and the linkage of INI DRMs with PI and RTI DRMs in these patients plus 6 RAL-treated patients. A one-step RT-nested PCR protocol was used to generate a 2.7 kB amplicon that included the PR, RT, and IN coding region, and standard cloning and sequencing techniques were used to determine DRMs in 1,277 clones (mean 21 clones per time point. Results showed all patients had multiple PI, NRTI, and/or NNRTI DRMs at baseline, but no primary INI DRM. EVG-treated patients developed from 2 to 6 strains with different primary INI DRMs as early as 2 weeks after initiation of treatment, predominantly as single mutations. The prevalence of these strains fluctuated and new strains, and/or strains with new combinations of INI DRMs, developed over time. Final failure samples (weeks 14 to 48 typically showed a dominant strain with multiple mutations or N155H alone. Single N155H or multiple mutations were also observed in RAL-treated patients at virologic failure. All patient strains showed evidence of INI DRM co-located with single or multiple PI and/or RTI DRMs on the same viral strand. Our study shows that EVG treatment can select for a number of distinct INI-resistant strains whose prevalence fluctuates over time. Continued appearance of new INI DRMs after initial INI failure suggests a potent, highly dynamic selection of INI resistant strains that is unaffected by co-location with PI and RTI DRMs.

Phosphatidylcholine transfer protein interacts with thioesterase superfamily member 2 to attenuate insulin signaling.

Science.gov (United States)

Ersoy, Baran A; Tarun, Akansha; D'Aquino, Katharine; Hancer, Nancy J; Ukomadu, Chinweike; White, Morris F; Michel, Thomas; Manning, Brendan D; Cohen, David E

2013-07-30

Phosphatidylcholine transfer protein (PC-TP) is a phospholipid-binding protein that is enriched in liver and that interacts with thioesterase superfamily member 2 (THEM2). Mice lacking either protein exhibit improved hepatic glucose homeostasis and are resistant to diet-induced diabetes. Insulin receptor substrate 2 (IRS2) and mammalian target of rapamycin complex 1 (mTORC1) are key effectors of insulin signaling, which is attenuated in diabetes. We found that PC-TP inhibited IRS2, as evidenced by insulin-independent IRS2 activation after knockdown, genetic ablation, or chemical inhibition of PC-TP. In addition, IRS2 was activated after knockdown of THEM2, providing support for a role for the interaction of PC-TP with THEM2 in suppressing insulin signaling. Additionally, we showed that PC-TP bound to tuberous sclerosis complex 2 (TSC2) and stabilized the components of the TSC1-TSC2 complex, which functions to inhibit mTORC1. Preventing phosphatidylcholine from binding to PC-TP disrupted interactions of PC-TP with THEM2 and TSC2, and disruption of the PC-TP-THEM2 complex was associated with increased activation of both IRS2 and mTORC1. In livers of mice with genetic ablation of PC-TP or that had been treated with a PC-TP inhibitor, steady-state amounts of IRS2 were increased, whereas those of TSC2 were decreased. These findings reveal a phospholipid-dependent mechanism that suppresses insulin signaling downstream of its receptor.

Profiles of HIV-infected anti-retroviral therapy naïve children from Mumbai, India.

Science.gov (United States)

Paranjpe, Supriya Mayur; Sarkate, Purva Pankaj; Ingole, Nayana Avinash; Raut, Shweta Sadanand; Mehta, Preeti Rajeev

2016-11-01

This study aimed to investigate the demographic profiles of human immunodifficiency virus (HIV) infected anti-retroviral therapy (ART) naïve children in our hospital and their relations to the clinical, immunological and nutritional status. A cross-sectional study was conducted in an Integrated Counselling and Testing Center (ICTC) at a tertiary care hospital in Mumbai. ART naïve HIV positive children were enrolled in the study. The demographic profiles, clinical features, immunological (CD4%/CD4 count) and nutritional status of these children were recorded. The agreement between clinical, immunological and nutritional staging was determined using Cohen's kappa test. In 192 HIV-infected ART naive children enrolled with a median age of 9 years (range 3 months-14 years), 97.4% acquired infection through vertical transmission. The most common clinical presentation was fever (39.6 %), followed by generalized lymphadenopathy (32.3%), cough (22.4%) and diarrhoea (9.9%). Tuberculosis was seen in 22.9% of the children. The agreement was fair between clinical and immunological staging, and slight between nutritional, immunological and clinical staging. Perinatal transmission is the most common mode of acquiring HIV infection in children. The Prevention of Parent to Child Transmission (PPTCT) program should be strengthened for lowering the transmission rate by providing extended ART to mothers during pregnancy and breast-feeding. Tuberculosis remains a major concern in HIV-infected children. The poor correlation between WHO clinical and immunological staging emphasizes the importance of making CD4 facilities available in HIV prevalent areas. Malnutrition cannot be used as a surrogate marker for predicting stage or severity as it is common at all stages of HIV disease.

Fairness and equity in the provision of anti-retroviral therapy: some reflections from Lesotho.

Science.gov (United States)

Armstrong, Russell

2010-12-01

The number of people in immediate need of anti-retroviral treatment (ART) in the southern African region continues to significantly exceed the capacity of health systems there to provide it. Approaches to this complex rationing dilemma have evolved in different directions. The ethical concepts of fairness and equity have been suggested as a basis to guide the development of approaches to select patients for ART. This article reports the results of a case study on patient selection at a rural ART clinic in Lesotho. The purpose of the study was to examine whether or not such concepts had relevance or operative value for a treatment team providing ART in rural Lesotho. The study found that while concepts of fairness and equity were relevant to the work of the treatment team, patient selection practices did not necessarily reflect what these concepts entail. The idea of fairness as a structured, formalized selection process did not figure in the approach to ART provision at the site. A less formal, 'first-come-first-served' approach was adopted. While there was knowledge among some team members that social, economic or geographic conditions inhibit individuals and groups from gaining access to ART and that this was inequitable, it was felt that there was little they could do to try to mediate the impact of these conditions. The study's findings pose importance questions about the approach to ART programming in resource constrained settings. The findings also question the relevance of trying to achieve fairness and equity when the gap between need for care and capacity to provide it remains so large. © 2009 Blackwell Publishing Ltd.

Effect of temperature on the fate of genes encoding tetracycline resistance and the integrase of class 1 integrons within anaerobic and aerobic digesters treating municipal wastewater solids.

Science.gov (United States)

Diehl, David L; LaPara, Timothy M

2010-12-01

The objective of this research was to investigate the ability of anaerobic and aerobic digesters to reduce the quantity of antibiotic resistant bacteria in wastewater solids. Lab-scale digesters were operated at different temperatures (22 °C, 37 °C, 46 °C, and 55 °C) under both anaerobic and aerobic conditions and fed wastewater solids collected from a full-scale treatment facility. Quantitative PCR was used to track five genes encoding tetracycline resistance (tet(A), tet(L), tet(O), tet(W), and tet(X)) and the gene encoding the integrase (intI1) of class 1 integrons. Statistically significant reductions in the quantities of these genes occurred in the anaerobic reactors at 37 °C, 46 °C, and 55 °C, with the removal rates and removal efficiencies increasing as a function of temperature. The aerobic digesters, in contrast, were generally incapable of significantly decreasing gene quantities, although these digesters were operated at much shorter mean hydraulic residence times. This research suggests that high temperature anaerobic digestion of wastewater solids would be a suitable technology for eliminating various antibiotic resistance genes, an emerging pollutant of concern.

A Single-Center Retrospective Cohort Analysis of Maternal and Infant Outcomes in HIV-Infected Mothers Treated with Integrase Inhibitors During Pregnancy.

Science.gov (United States)

Mounce, Monique L; Pontiggia, Laura; Adams, Jessica L

2017-12-01

Integrase strand transfer inhibitors (INSTI) are currently being investigated for the treatment of HIV in pregnancy. The purpose of this study is to evaluate the differences in maternal and infant outcomes in HIV-positive mothers treated with INSTI-containing antiretroviral therapy (ART) during pregnancy compared to protease inhibitor (PI)-containing ART. A retrospective, cohort study of INSTI- and PI-based ART used in pregnancy between 2007 and 2015 was performed. The primary objective was to evaluate the differences in viral load (VL) suppression prior to delivery. Secondary endpoints included time to and duration of VL suppression and safety parameters in both mothers and infants. For the primary analysis, the two arms were matched 1:2 INSTI to PI based on the presence or absence of viremia at the time of pregnancy determination. Additional analysis was performed on the entire matched and unmatched dataset. Twenty-one patients were matched (7 INSTI and 14 PI). There were no significant differences between groups with respect to the proportion of patients with VL suppression prior to delivery (71.4% INSTI vs. 92.9% PI, p = 0.247), and there were no significant differences in any of the secondary endpoints. Patients with documented adherence issues were statistically more likely to not be virologically suppressed prior to delivery (p = 0.002). No differences in efficacy or safety were found between patients treated with INSTIs compared to PIs. This study supports the further investigation of the use of INSTIs during pregnancy to reduce HIV transmission.

Mutational analyses of the core domain of Avian Leukemia and Sarcoma Viruses integrase: critical residues for concerted integration and multimerization

International Nuclear Information System (INIS)

Moreau, Karen; Faure, Claudine; Violot, Sebastien; Gouet, Patrice; Verdier, Gerard; Ronfort, Corinne

2004-01-01

During replicative cycle of retroviruses, the reverse-transcribed viral DNA is integrated into the cell DNA by the viral integrase (IN) enzyme. The central core domain of IN contains the catalytic site of the enzyme and is involved in binding viral ends and cell DNA as well as dimerization. We previously performed single amino acid substitutions in the core domain of an Avian Leukemia and Sarcoma Virus (ALSV) IN [Arch. Virol. 147 (2002) 1761]. Here, we modeled the resulting IN mutants and analyzed the ability of these mutants to mediate concerted DNA integration in an in vitro assay, and to form dimers by protein-protein cross-linking and size exclusion chromatography. The N197C mutation resulted in the inability of the mutant to perform concerted integration that was concomitant with a loss of IN dimerization. Surprisingly, mutations Q102G and A106V at the dimer interface resulted in mutants with higher efficiencies than the wild-type IN in performing two-ended concerted integration of viral DNA ends. The G139D and A195V mutants had a trend to perform one-ended DNA integration of viral ends instead of two-ended integration. More drastically, the I88L and L135G mutants preferentially mediated nonconcerted DNA integration although the proteins form dimers. Therefore, these mutations may alter the formation of IN complexes of higher molecular size than a dimer that would be required for concerted integration. This study points to the important role of core domain residues in the concerted integration of viral DNA ends as well as in the oligomerization of the enzyme

Gene therapy for adenosine deaminase-deficient severe combined immune deficiency: clinical comparison of retroviral vectors and treatment plans.

Science.gov (United States)

Candotti, Fabio; Shaw, Kit L; Muul, Linda; Carbonaro, Denise; Sokolic, Robert; Choi, Christopher; Schurman, Shepherd H; Garabedian, Elizabeth; Kesserwan, Chimene; Jagadeesh, G Jayashree; Fu, Pei-Yu; Gschweng, Eric; Cooper, Aaron; Tisdale, John F; Weinberg, Kenneth I; Crooks, Gay M; Kapoor, Neena; Shah, Ami; Abdel-Azim, Hisham; Yu, Xiao-Jin; Smogorzewska, Monika; Wayne, Alan S; Rosenblatt, Howard M; Davis, Carla M; Hanson, Celine; Rishi, Radha G; Wang, Xiaoyan; Gjertson, David; Yang, Otto O; Balamurugan, Arumugam; Bauer, Gerhard; Ireland, Joanna A; Engel, Barbara C; Podsakoff, Gregory M; Hershfield, Michael S; Blaese, R Michael; Parkman, Robertson; Kohn, Donald B

2012-11-01

We conducted a gene therapy trial in 10 patients with adenosine deaminase (ADA)-deficient severe combined immunodeficiency using 2 slightly different retroviral vectors for the transduction of patients' bone marrow CD34(+) cells. Four subjects were treated without pretransplantation cytoreduction and remained on ADA enzyme-replacement therapy (ERT) throughout the procedure. Only transient (months), low-level (< 0.01%) gene marking was observed in PBMCs of 2 older subjects (15 and 20 years of age), whereas some gene marking of PBMC has persisted for the past 9 years in 2 younger subjects (4 and 6 years). Six additional subjects were treated using the same gene transfer protocol, but after withdrawal of ERT and administration of low-dose busulfan (65-90 mg/m(2)). Three of these remain well, off ERT (5, 4, and 3 years postprocedure), with gene marking in PBMC of 1%-10%, and ADA enzyme expression in PBMC near or in the normal range. Two subjects were restarted on ERT because of poor gene marking and immune recovery, and one had a subsequent allogeneic hematopoietic stem cell transplantation. These studies directly demonstrate the importance of providing nonmyeloablative pretransplantation conditioning to achieve therapeutic benefits with gene therapy for ADA-deficient severe combined immunodeficiency.

Gene therapy for adenosine deaminase–deficient severe combined immune deficiency: clinical comparison of retroviral vectors and treatment plans

Science.gov (United States)

Candotti, Fabio; Shaw, Kit L.; Muul, Linda; Carbonaro, Denise; Sokolic, Robert; Choi, Christopher; Schurman, Shepherd H.; Garabedian, Elizabeth; Kesserwan, Chimene; Jagadeesh, G. Jayashree; Fu, Pei-Yu; Gschweng, Eric; Cooper, Aaron; Tisdale, John F.; Weinberg, Kenneth I.; Crooks, Gay M.; Kapoor, Neena; Shah, Ami; Abdel-Azim, Hisham; Yu, Xiao-Jin; Smogorzewska, Monika; Wayne, Alan S.; Rosenblatt, Howard M.; Davis, Carla M.; Hanson, Celine; Rishi, Radha G.; Wang, Xiaoyan; Gjertson, David; Yang, Otto O.; Balamurugan, Arumugam; Bauer, Gerhard; Ireland, Joanna A.; Engel, Barbara C.; Podsakoff, Gregory M.; Hershfield, Michael S.; Blaese, R. Michael; Parkman, Robertson

2012-01-01

We conducted a gene therapy trial in 10 patients with adenosine deaminase (ADA)–deficient severe combined immunodeficiency using 2 slightly different retroviral vectors for the transduction of patients' bone marrow CD34+ cells. Four subjects were treated without pretransplantation cytoreduction and remained on ADA enzyme-replacement therapy (ERT) throughout the procedure. Only transient (months), low-level (< 0.01%) gene marking was observed in PBMCs of 2 older subjects (15 and 20 years of age), whereas some gene marking of PBMC has persisted for the past 9 years in 2 younger subjects (4 and 6 years). Six additional subjects were treated using the same gene transfer protocol, but after withdrawal of ERT and administration of low-dose busulfan (65-90 mg/m2). Three of these remain well, off ERT (5, 4, and 3 years postprocedure), with gene marking in PBMC of 1%-10%, and ADA enzyme expression in PBMC near or in the normal range. Two subjects were restarted on ERT because of poor gene marking and immune recovery, and one had a subsequent allogeneic hematopoietic stem cell transplantation. These studies directly demonstrate the importance of providing nonmyeloablative pretransplantation conditioning to achieve therapeutic benefits with gene therapy for ADA-deficient severe combined immunodeficiency. PMID:22968453

Mesenchymal stromal cells retrovirally transduced with prodrug-converting genes are suitable vehicles for cancer gene therapy.

Science.gov (United States)

Ďuriniková, E; Kučerová, L; Matúšková, M

2014-01-01

Mesenchymal stem/stromal cells (MSC) possess a set of several fairly unique properties which make them ideally suitable both for cellular therapies and regenerative medicine. These include: relative ease of isolation, the ability to differentiate along mesenchymal and non-mesenchymal lineages in vitro and the ability to be extensively expanded in culture without a loss of differentiative capacity. MSC are not only hypoimmunogenic, but they mediate immunosuppression upon transplantation, and possess pronounced anti-inflammatory properties. They are able to home to damaged tissues, tumors, and metastases following systemic administration. The ability of homing holds big promise for tumor-targeted delivery of therapeutic agents. Viruses are naturally evolved vehicles efficiently transferring their genes into host cells. This ability made them suitable for engineering vector systems for the delivery of genes of interest. MSC can be retrovirally transduced with genes encoding prodrug-converting genes (suicide genes), which are not toxic per se, but catalyze the formation of highly toxic metabolites following the application of a nontoxic prodrug. The homing ability of MSC holds advantages compared to virus vehicles which display many shortcomings in effective delivery of the therapeutic agents. Gene therapies mediated by viruses are limited by their restricted ability to track cancer cells infiltrating into the surrounding tissue, and by their low migratory capacity towards tumor. Thus combination of cellular therapy and gene delivery is an attractive option - it protects the vector from immune surveillance, and supports targeted delivery of a therapeutic gene/protein to the tumor site.

A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria

Science.gov (United States)

Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Íñigo; Novick, Richard P.; Christie, Gail E.; Penadés, José R.

2013-01-01

The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

Oral pre-exposure prophylaxis by anti-retrovirals raltegravir and maraviroc protects against HIV-1 vaginal transmission in a humanized mouse model.

Directory of Open Access Journals (Sweden)

C Preston Neff

Full Text Available Sexual HIV-1 transmission by vaginal route is the most predominant mode of viral transmission, resulting in millions of new infections every year. In the absence of an effective vaccine, there is an urgent need to develop other alternative methods of pre-exposure prophylaxis (PrEP. Many novel drugs that are currently approved for clinical use also show great potential to prevent viral sexual transmission when administered systemically. A small animal model that permits rapid preclinical evaluation of potential candidates for their systemic PrEP efficacy will greatly enhance progress in this area of investigation. We have previously shown that RAG-hu humanized mouse model permits HIV-1 mucosal transmission via both vaginal and rectal routes and displays CD4 T cell loss typical to that seen in the human. Thus far systemic PrEP studies have been primarily limited to RT inhibitors exemplified by tenofovir and emtricitabine. In these proof-of-concept studies we evaluated two new classes of clinically approved drugs with different modes of action namely, an integrase inhibitor raltegravir and a CCR5 inhibitor maraviroc as potential systemically administered chemo-prophylactics. Our results showed that oral administration of either of these drugs fully protects against vaginal HIV-1 challenge in the RAG-hu mouse model. Based on these results both these drugs show great promise for further development as orally administered PrEPs.

Simultaneous RNA quantification of human and retroviral genomes reveals intact interferon signaling in HTLV-1-infected CD4+ T cell lines

Directory of Open Access Journals (Sweden)

Moens Britta

2012-08-01

Full Text Available Abstract Background IFN-α contributes extensively to host immune response upon viral infection through antiviral, pro-apoptotic, antiproliferative and immunomodulatory activities. Although extensively documented in various types of human cancers and viral infections, controversy exists in the exact mechanism of action of IFN-α in human immunodeficiency virus type 1 (HIV-1 and human T-lymphotropic virus type 1 (HTLV-1 retroviral infections. Results IFN-α displayed strong anti-HIV-1 effects in HIV-1/HTLV-1 co-infected MT-4 cells in vitro, demonstrated by the dose-dependent inhibition of the HIV-1-induced cytopathic effect (IC50 = 83.5 IU/ml, p 50 = 1.2 IU/ml, p  Conclusions Taken together, our results indicate that both the absence of in vitro antiproliferative and pro-apoptotic activity as well as the modest post-transcriptional antiviral activity of IFN-α against HTLV-1, were not due to a cell-intrinsic defect in IFN-α signalisation, but rather represents a retrovirus-specific phenomenon, considering the strong HIV-1 inhibition in co-infected cells.

Mode of inhibition of HIV-1 Integrase by a C-terminal domain-specific monoclonal antibody*

Directory of Open Access Journals (Sweden)

Merkel George

2006-06-01

Full Text Available Abstract Background To further our understanding of the structure and function of HIV-1 integrase (IN we developed and characterized a library of monoclonal antibodies (mAbs directed against this protein. One of these antibodies, mAb33, which is specific for the C-terminal domain, was found to inhibit HIV-1 IN processing activity in vitro; a corresponding Fv fragment was able to inhibit HIV-1 integration in vivo. Our subsequent studies, using heteronuclear nuclear magnetic resonance spectroscopy, identified six solvent accessible residues on the surface of the C-terminal domain that were immobilized upon binding of the antibody, which were proposed to comprise the epitope. Here we test this hypothesis by measuring the affinity of mAb33 to HIV-1 proteins that contain Ala substitutions in each of these positions. To gain additional insight into the mode of inhibition we also measured the DNA binding capacity and enzymatic activities of the Ala substituted proteins. Results We found that Ala substitution of any one of five of the putative epitope residues, F223, R224, Y226, I267, and I268, caused a decrease in the affinity of the mAb33 for HIV-1 IN, confirming the prediction from NMR data. Although IN derivatives with Ala substitutions in or near the mAb33 epitope exhibited decreased enzymatic activity, none of the epitope substitutions compromised DNA binding to full length HIV-1 IN, as measured by surface plasmon resonance spectroscopy. Two of these derivatives, IN (I276A and IN (I267A/I268A, exhibited both increased DNA binding affinity and uncharacteristic dissociation kinetics; these proteins also exhibited non-specific nuclease activity. Results from these investigations are discussed in the context of current models for how the C-terminal domain interacts with substrate DNA. Conclusion It is unlikely that inhibition of HIV-1 IN activity by mAb33 is caused by direct interaction with residues that are essential for substrate binding. Rather

Vinorine synthase from Rauvolfia: the first example of crystallization and preliminary X-ray diffraction analysis of an enzyme of the BAHD superfamily.

Science.gov (United States)

Ma, Xueyan; Koepke, Juergen; Bayer, Anja; Linhard, Verena; Fritzsch, Günter; Zhang, Bin; Michel, Hartmut; Stöckigt, Joachim

2004-09-01

Crystals of vinorine synthase (VS) from medicinal plant Rauvolfia serpentina expressed in Escherichia coli have been obtained by the hanging-drop technique at 305 K with ammonium sulfate and PEG 400 as precipitants. The enzyme is involved in the biosynthesis of the antiarrhythmic drug ajmaline and is a member of the BAHD superfamily of acyltransferases. So far, no three-dimensional structure of a member of this enzyme family is known. The crystals belong to the space group P2(1)2(1)2(1) with cell dimensions of a=82.3 A, b=89.6 A and c=136.2 A. Under cryoconditions (120 K), a complete data set up to 2.8 A was collected at a synchrotron source.

A stable murine-based RD114 retroviral packaging line efficiently transduces human hematopoietic cells.

Science.gov (United States)

Ward, Maureen; Sattler, Rose; Grossman, I Robert; Bell, Anthony J; Skerrett, Donna; Baxi, Laxmi; Bank, Arthur

2003-11-01

Several barriers exist to high-efficiency transfer of therapeutic genes into human hematopoietic stem cells (HSCs) using complex oncoretroviral vectors. Human clinical trials to date have used Moloney leukemia virus-based amphotropic and gibbon ape leukemia virus-based envelopes in stable retroviral packaging lines. However, retroviruses pseudotyped with these envelopes have low titers due to the inability to concentrate viral supernatants efficiently by centrifugation without damaging the virus and low transduction efficiencies because of low-level expression of viral target receptors on human HSC. The RD114 envelope from the feline endogenous virus has been shown to transduce human CD34+ cells using transient packaging systems and to be concentrated to high titers by centrifugation. Stable packaging systems have potential advantages over transient systems because greater and more reproducible viral productions can be attained. We have, therefore, constructed and tested a stable RD114-expressing packaging line capable of high-level transduction of human CD34+ cells. Viral particles from this cell line were concentrated up to 100-fold (up to 10(7) viral particles/ml) by ultracentrifugation. Human hematopoietic progenitors from cord blood and sickle cell CD34+ cells were efficiently transduced with a Neo(R)-containing vector after a single exposure to concentrated RD114-pseudotyped virus produced from this cell line. Up to 78% of progenitors from transduced cord blood CD34+ cells and 51% of progenitors from sickle cell CD34+ cells expressed the NeoR gene. We also show transfer of a human beta-globin gene into progenitor cells from CD34+ cells from sickle cell patients with this new RD114 stable packaging system. The results indicate that this packaging line may eventually be useful in human clinical trials of globin gene therapy.

A novel co-crystal structure affords the design of gain-of-function lentiviral integrase mutants in the presence of modified PSIP1/LEDGF/p75.

Directory of Open Access Journals (Sweden)

Stephen Hare

2009-01-01

Full Text Available Lens epithelium derived growth factor (LEDGF, also known as PC4 and SFRS1 interacting protein 1 (PSIP1 and transcriptional co-activator p75, is the cellular binding partner of lentiviral integrase (IN proteins. LEDGF accounts for the characteristic propensity of Lentivirus to integrate within active transcription units and is required for efficient viral replication. We now present a crystal structure containing the N-terminal and catalytic core domains (NTD and CCD of HIV-2 IN in complex with the IN binding domain (IBD of LEDGF. The structure extends the known IN-LEDGF interface, elucidating primarily charge-charge interactions between the NTD of IN and the IBD. A constellation of acidic residues on the NTD is characteristic of lentiviral INs, and mutations of the positively charged residues on the IBD severely affect interaction with all lentiviral INs tested. We show that the novel NTD-IBD contacts are critical for stimulation of concerted lentiviral DNA integration by LEDGF in vitro and for its function during the early steps of HIV-1 replication. Furthermore, the new structural details enabled us to engineer a mutant of HIV-1 IN that primarily functions only when presented with a complementary LEDGF mutant. These findings provide structural basis for the high affinity lentiviral IN-LEDGF interaction and pave the way for development of LEDGF-based targeting technologies for gene therapy.

Retroviral insertions in the VISION database identify molecular pathways in mouse lymphoid leukemia and lymphoma.

Science.gov (United States)

Weiser, Keith C; Liu, Bin; Hansen, Gwenn M; Skapura, Darlene; Hentges, Kathryn E; Yarlagadda, Sujatha; Morse Iii, Herbert C; Justice, Monica J

2007-10-01

AKXD recombinant inbred (RI) strains develop a variety of leukemias and lymphomas due to somatically acquired insertions of retroviral DNA into the genome of hematopoetic cells that can mutate cellular proto-oncogenes and tumor suppressor genes. We generated a new set of tumors from nine AKXD RI strains selected for their propensity to develop B-cell tumors, the most common type of human hematopoietic cancers. We employed a PCR technique called viral insertion site amplification (VISA) to rapidly isolate genomic sequence at the site of provirus insertion. Here we describe 550 VISA sequence tags (VSTs) that identify 74 common insertion sites (CISs), of which 21 have not been identified previously. Several suspected proto-oncogenes and tumor suppressor genes lie near CISs, providing supportive evidence for their roles in cancer. Furthermore, numerous previously uncharacterized genes lie near CISs, providing a pool of candidate disease genes for future research. Pathway analysis of candidate genes identified several signaling pathways as common and powerful routes to blood cancer, including Notch, E-protein, NFkappaB, and Ras signaling. Misregulation of several Notch signaling genes was confirmed by quantitative RT-PCR. Our data suggest that analyses of insertional mutagenesis on a single genetic background are biased toward the identification of cooperating mutations. This tumor collection represents the most comprehensive study of the genetics of B-cell leukemia and lymphoma development in mice. We have deposited the VST sequences, CISs in a genome viewer, histopathology, and molecular tumor typing data in a public web database called VISION (Viral Insertion Sites Identifying Oncogenes), which is located at http://www.mouse-genome.bcm.tmc.edu/vision .

Resistance to pyridine-based inhibitor KF116 reveals an unexpected role of integrase in HIV-1 Gag-Pol polyprotein proteolytic processing.

Science.gov (United States)

Hoyte, Ashley C; Jamin, Augusta V; Koneru, Pratibha C; Kobe, Matthew J; Larue, Ross C; Fuchs, James R; Engelman, Alan N; Kvaratskhelia, Mamuka

2017-12-01

The pyridine-based multimerization selective HIV-1 integrase (IN) inhibitors (MINIs) are a distinct subclass of allosteric IN inhibitors. MINIs potently inhibit HIV-1 replication during virion maturation by inducing hyper- or aberrant IN multimerization but are largely ineffective during the early steps of viral replication. Here, we investigated the mechanism for the evolution of a triple IN substitution (T124N/V165I/T174I) that emerges in cell culture with a representative MINI, KF116. We show that HIV-1 NL4-3(IN T124N/V165I/T174I) confers marked (>2000-fold) resistance to KF116. Two IN substitutions (T124N/T174I) directly weaken inhibitor binding at the dimer interface of the catalytic core domain but at the same time markedly impair HIV-1 replication capacity. Unexpectedly, T124N/T174I IN substitutions inhibited proteolytic processing of HIV-1 polyproteins Gag and Gag-Pol, resulting in immature virions. Strikingly, the addition of the third IN substitution (V165I) restored polyprotein processing, virus particle maturation, and significant levels of replication capacity. These results reveal an unanticipated role of IN for polyprotein proteolytic processing during virion morphogenesis. The complex evolutionary pathway for the emergence of resistant viruses, which includes the need for the compensatory V165I IN substitution, highlights a relatively high genetic barrier exerted by MINI KF116. Additionally, we have solved the X-ray structure of the drug-resistant catalytic core domain protein, which provides means for rational development of second-generation MINIs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

A quantitative structure–activity relationship study on HIV-1 integrase inhibitors using genetic algorithm, artificial neural networks and different statistical methods

Directory of Open Access Journals (Sweden)

Ghasem Ghasemi

2016-09-01

Full Text Available In this work, quantitative structure–activity relationship (QSAR study has been done on tricyclic phthalimide analogues acting as HIV-1 integrase inhibitors. Forty compounds were used in this study. Genetic algorithm (GA, artificial neural network (ANN and multiple linear regressions (MLR were utilized to construct the non-linear and linear QSAR models. It revealed that the GA–ANN model was much better than other models. For this purpose, ab initio geometry optimization performed at B3LYP level with a known basis set 6–31G (d. Hyperchem, ChemOffice and Gaussian 98W softwares were used for geometry optimization of the molecules and calculation of the quantum chemical descriptors. To include some of the correlation energy, the calculation was done with the density functional theory (DFT with the same basis set and Becke’s three parameter hybrid functional using the LYP correlation functional (B3LYP/6–31G (d. For the calculations in solution phase, the polarized continuum model (PCM was used and also included optimizations at gas-phase B3LYP/6–31G (d level for comparison. In the aqueous phase, the root–mean–square errors of the training set and the test set for GA–ANN model using jack–knife method, were 0.1409, 0.1804, respectively. In the gas phase, the root–mean–square errors of the training set and the test set for GA–ANN model were 0.1408, 0.3103, respectively. Also, the R2 values in the aqueous and the gas phase were obtained as 0.91, 0.82, respectively.

Gene transfer to pre-hematopoietic and committed hematopoietic precursors in the early mouse Yolk Sac: a comparative study between in situ electroporation and retroviral transduction

Directory of Open Access Journals (Sweden)

Lécluse Yann

2007-07-01

Full Text Available Abstract Background Hematopoietic development in vertebrate embryos results from the sequential contribution of two pools of precursors independently generated. While intra-embryonic precursors harbour the features of hematopoietic stem cells (HSC, precursors formed earlier in the yolk sac (YS display limited differentiation and self-renewal potentials. The mechanisms leading to the generation of the precursors in both sites are still largely unknown, as are the molecular basis underlying their different potential. A possible approach to assess the role of candidate genes is to transfer or modulate their expression/activity in both sites. We thus designed and compared transduction protocols to target either native extra-embryonic precursors, or hematopoietic precursors. Results One transduction protocol involves transient modification of gene expression through in situ electroporation of the prospective blood islands, which allows the evolution of transfected mesodermal cells in their "normal" environment, upon organ culture. Following in situ electroporation of a GFP reporter construct into the YS cavity of embryos at post-streak (mesodermal/pre-hematopoietic precursors or early somite (hematopoietic precursors stages, high GFP expression levels as well as a good preservation of cell viability is observed in YS explants. Moreover, the erythro-myeloid progeny typical of the YS arises from GFP+ mesodermal cells or hematopoietic precursors, even if the number of targeted precursors is low. The second approach, based on retroviral transduction allows a very efficient transduction of large precursor numbers, but may only be used to target 8 dpc YS hematopoietic precursors. Again, transduced cells generate a progeny quantitatively and qualitatively similar to that of control YS. Conclusion We thus provide two protocols whose combination may allow a thorough study of both early and late events of hematopoietic development in the murine YS. In situ

Foxp3-dependent transformation of human primary CD4+ T lymphocytes by the retroviral protein tax.

Science.gov (United States)

Chen, Li; Liu, Dan; Zhang, Yang; Zhang, Huan; Cheng, Hua

2015-10-23

The retroviral Tax proteins of human T cell leukemia virus type 1 and 2 (HTLV-1 and -2) are highly homologous viral transactivators. Both viral proteins can immortalize human primary CD4+ memory T cells, but when expressed alone they rarely transform T cells. In the present study, we found that the Tax proteins displayed a differential ability to immortalize human CD4+Foxp3+ T cells with characteristic expression of CTLA-4 and GITR. Because epidermal growth factor receptor (EGFR) was reportedly expressed and activated in a subset of CD4+Foxp3+ T cells, we introduced an activated EGFR into Tax-immortalized CD4+Foxp3+ T cells. We observed that these modified cells were grown independently of exogenous IL-2, correlating with a T cell transformation phenotype. In Tax-immortalized CD4+Foxp3- T cells, ectopic expression of Foxp3 was a prerequisite for Tax transformation of T cells. Accordingly, treatment of the transformed T cells with erlotinib, a selective inhibitor of EGFR, induced degradation of EGFR in lysosome, consequently causing T cell growth inhibition. Further, we identified autophagy as a crucial cellular survival pathway for the transformed T cells. Silencing key autophagy molecules including Beclin1, Atg5 and PI3 kinase class III (PI3KC3) resulted in drastic impairment of T cell growth. Our data, therefore, unveiled a previously unidentified role of Foxp3 in T cell transformation, providing a molecular basis for HTLV-1 transformation of CD4+Foxp3+ T cells. Copyright © 2015 Elsevier Inc. All rights reserved.

A Novel Superfamily of Transporters for Allantoin and Other Oxo Derivatives of Nitrogen Heterocyclic Compounds in Arabidopsis

Science.gov (United States)

Desimone, Marcelo; Catoni, Elisabetta; Ludewig, Uwe; Hilpert, Melanie; Schneider, Anja; Kunze, Reinhard; Tegeder, Mechthild; Frommer, Wolf Bernd; Schumacher, Karin

2002-01-01

A wide spectrum of soil heterocyclic nitrogen compounds are potential nutrients for plants. Here, it is shown that Arabidopsis plants are able to use allantoin as sole nitrogen source. By functional complementation of a yeast mutant defective in allantoin uptake, an Arabidopsis transporter, AtUPS1 (Arabidopsis thaliana ureide permease 1), was identified. AtUPS1 belongs to a novel superfamily of plant membrane proteins with five open reading frames in Arabidopsis (identity, 64 to 82%). UPS proteins have 10 putative transmembrane domains with a large cytosolic central domain containing a “Walker A” motif. Transport of 14C-labeled allantoin by AtUPS1 in yeast exhibited saturation kinetics (Km ∼ 52 μM), was dependent on Glc and a proton gradient, and was stimulated by acidic pH. AtUPS1 transports uric acid and xanthine, besides allantoin, but not adenine. Protons are cosubstrates in allantoin transport by AtUPS1, as demonstrated by expression in Xenopus laevis oocytes. In plants, AtUPS1 gene expression was dependent on the nitrogen source. Therefore, AtUPS1 presumably is involved in the uptake of allantoin and other purine degradation products when primary sources are limiting. PMID:11971139

New insights into potential functions for the protein 4.1superfamily of proteins in kidney epithelium

Energy Technology Data Exchange (ETDEWEB)

Calinisan, Venice; Gravem, Dana; Chen, Ray Ping-Hsu; Brittin,Sachi; Mohandas, Narla; Lecomte, Marie-Christine; Gascard, Philippe

2005-06-17

Members of the protein 4.1 family of adapter proteins are expressed in a broad panel of tissues including various epithelia where they likely play an important role in maintenance of cell architecture and polarity and in control of cell proliferation. We have recently characterized the structure and distribution of three members of the protein 4.1 family, 4.1B, 4.1R and 4.1N, in mouse kidney. We describe here binding partners for renal 4.1 proteins, identified through the screening of a rat kidney yeast two-hybrid system cDNA library. The identification of putative protein 4.1-based complexes enables us to envision potential functions for 4.1 proteins in kidney: organization of signaling complexes, response to osmotic stress, protein trafficking, and control of cell proliferation. We discuss the relevance of these protein 4.1-based interactions in kidney physio-pathology in the context of their previously identified functions in other cells and tissues. Specifically, we will focus on renal 4.1 protein interactions with beta amyloid precursor protein (beta-APP), 14-3-3 proteins, and the cell swelling-activated chloride channel pICln. We also discuss the functional relevance of another member of the protein 4.1 superfamily, ezrin, in kidney physiopathology.

The crystal structures of the tri-functional Chloroflexus aurantiacus and bi-functional Rhodobacter sphaeroides malyl-CoA lyases and comparison with CitE-like superfamily enzymes and malate synthases.

Science.gov (United States)

Zarzycki, Jan; Kerfeld, Cheryl A

2013-11-09

Malyl-CoA lyase (MCL) is a promiscuous carbon-carbon bond lyase that catalyzes the reversible cleavage of structurally related Coenzyme A (CoA) thioesters. This enzyme plays a crucial, multifunctional role in the 3-hydroxypropionate bi-cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus. A second, phylogenetically distinct MCL from Rhodobacter sphaeroides is involved in the ethylmalonyl-CoA pathway for acetate assimilation. Both MCLs belong to the large superfamily of CitE-like enzymes, which includes the name-giving β-subunit of citrate lyase (CitE), malyl-CoA thioesterases and other enzymes of unknown physiological function. The CitE-like enzyme superfamily also bears sequence and structural resemblance to the malate synthases. All of these different enzymes share highly conserved catalytic residues, although they catalyze distinctly different reactions: C-C bond formation and cleavage, thioester hydrolysis, or both (the malate synthases). Here we report the first crystal structures of MCLs from two different phylogenetic subgroups in apo- and substrate-bound forms. Both the C. aurantiacus and the R. sphaeroides MCL contain elaborations on the canonical β8/α8 TIM barrel fold and form hexameric assemblies. Upon ligand binding, changes in the C-terminal domains of the MCLs result in closing of the active site, with the C-terminal domain of one monomer forming a lid over and contributing side chains to the active site of the adjacent monomer. The distinctive features of the two MCL subgroups were compared to known structures of other CitE-like superfamily enzymes and to malate synthases, providing insight into the structural subtleties that underlie the functional versatility of these enzymes. Although the C. aurantiacus and the R. sphaeroides MCLs have divergent primary structures (~37% identical), their tertiary and quaternary structures are very similar. It can be assumed that the C-C bond formation catalyzed by the MCLs occurs as proposed for

Development of pharmacophore similarity-based quantitative activity hypothesis and its applicability domain: applied on a diverse data-set of HIV-1 integrase inhibitors.

Science.gov (United States)

Kumar, Sivakumar Prasanth; Jasrai, Yogesh T; Mehta, Vijay P; Pandya, Himanshu A

2015-01-01

Quantitative pharmacophore hypothesis combines the 3D spatial arrangement of pharmacophore features with biological activities of the ligand data-set and predicts the activities of geometrically and/or pharmacophoric similar ligands. Most pharmacophore discovery programs face difficulties in conformational flexibility, molecular alignment, pharmacophore features sampling, and feature selection to score models if the data-set constitutes diverse ligands. Towards this focus, we describe a ligand-based computational procedure to introduce flexibility in aligning the small molecules and generating a pharmacophore hypothesis without geometrical constraints to define pharmacophore space, enriched with chemical features necessary to elucidate common pharmacophore hypotheses (CPHs). Maximal common substructure (MCS)-based alignment method was adopted to guide the alignment of carbon molecules, deciphered the MCS atom connectivity to cluster molecules in bins and subsequently, calculated the pharmacophore similarity matrix with the bin-specific reference molecules. After alignment, the carbon molecules were enriched with original atoms in their respective positions and conventional pharmacophore features were perceived. Distance-based pharmacophoric descriptors were enumerated by computing the interdistance between perceived features and MCS-aligned 'centroid' position. The descriptor set and biological activities were used to develop support vector machine models to predict the activities of the external test set. Finally, fitness score was estimated based on pharmacophore similarity with its bin-specific reference molecules to recognize the best and poor alignments and, also with each reference molecule to predict outliers of the quantitative hypothesis model. We applied this procedure to a diverse data-set of 40 HIV-1 integrase inhibitors and discussed its effectiveness with the reported CPH model.

Antiviral activity of dolutegravir in subjects with failure on an integrase inhibitor-based regimen: week 24 phase 3 results from VIKING-3

Science.gov (United States)

Nichols, G; Mills, A; Grossberg, R; Lazzarin, A; Maggiolo, F; Molina, J; Pialoux, G; Wright, D; Ait-Khaled, M; Huang, J; Vavro, C; Wynne, B; Yeo, J

2012-01-01

Background VIKING-3 aimed to examine efficacy and safety of dolutegravir (DTG) 50 mg twice daily in patients with resistance to multiple ARV classes, including integrase inhibitors (INI). Methods RAL and/or EVG-resistant (current or historical) adult subjects with screening plasma HIV-1 RNA ≥500 c/mL and resistance to ≥2 other ART classes received open-label DTG 50 mg BID while continuing their failing regimen (without RAL/EVG). At Day 8 the background regimen was optimised and DTG continued. Activity of the optimized background regimen (OBR) was determined by Monogram Net Assessment. Primary endpoints were antiviral efficacy at Day 8 and Week 24. Results 183 subjects enrolled, 124 with INI-resistance at screening and 59 with historical (but no screening) resistance. Population was advanced: at BL, median CD4 140, prior ART 13 yrs, 56% CDC Class C; 79% had >2 NRTI, 75% >1 NNRTI, and 70% >2 PI resistance-associated mutations, and 61% had non-R5 HIV detected. Of the 114 subjects who had the opportunity to complete 24 weeks on study before data cutoff, 72 (63%) had 1 log HIV RNA decline of 2, respectively. Discontinuations due to adverse events were uncommon (6/183, 3%); the most common drug-related AEs were diarrhoea, nausea and headache, each reported in only 5% of subjects. Conclusion A majority of the highly treatment-experienced subjects in VIKING-3 achieved suppression with DTG-based therapy. Responses were associated with Baseline IN genotype but not OSS, highlighting the importance and independence of DTG antiviral activity. DTG had a low rate of discontinuation due to adverse events at 50 mg BID in this advanced patient population.

Potential benefit of dolutegravir once daily: efficacy and safety

Directory of Open Access Journals (Sweden)

Fantauzzi A

2013-02-01

Full Text Available Alessandra Fantauzzi,1 Ombretta Turriziani,2 Ivano Mezzaroma11Department of Clinical Medicine, 2Department of Molecular Medicine, Sapienza, University of Rome, Rome, ItalyAbstract: The viral integrase enzyme has recently emerged as a primary alternative target to block HIV-1 replication, and integrase inhibitors are considered a pivotal new class of antiretroviral drugs. Dolutegravir is an investigational next-generation integrase inhibitor showing some novel and intriguing characteristics, ie, it has a favorable pharmacokinetic profile with a prolonged intracellular half-life, rendering feasible once-daily dosing without the need for ritonavir boosting and without regard to meals. Moreover, dolutegravir is primarily metabolized via uridine diphosphate glucuronosyltranferase 1A1, with a minor component of the cytochrome P450 3A4 isoform, thereby limiting drug–drug interactions. Furthermore, its metabolic profile enables coadministration with most of the other available antiretroviral agents without dose adjustment. Recent findings also demonstrate that dolutegravir has significant activity against HIV-1 isolates with resistance mutations associated with raltegravir and/or elvitegravir. The attributes of once-daily administration and the potential to treat integrase inhibitor-resistant viruses make dolutegravir an interesting and promising investigational drug. In this review, the main concerns about the efficacy and safety of dolutegravir as well as its resistance profile are explored by analysis of currently available data from preclinical and clinical studies.Keywords: antiretroviral drugs, HIV-1 integrase, integrase inhibitors, dolutegravir, once daily

Nuclear receptors from the ctenophore Mnemiopsis leidyi lack a zinc-finger DNA-binding domain: lineage-specific loss or ancestral condition in the emergence of the nuclear receptor superfamily?

Directory of Open Access Journals (Sweden)

Reitzel Adam M

2011-02-01

Full Text Available Abstract Background Nuclear receptors (NRs are an ancient superfamily of metazoan transcription factors that play critical roles in regulation of reproduction, development, and energetic homeostasis. Although the evolutionary relationships among NRs are well-described in two prominent clades of animals (deuterostomes and protostomes, comparatively little information has been reported on the diversity of NRs in early diverging metazoans. Here, we identified NRs from the phylum Ctenophora and used a phylogenomic approach to explore the emergence of the NR superfamily in the animal kingdom. In addition, to gain insight into conserved or novel functions, we examined NR expression during ctenophore development. Results We report the first described NRs from the phylum Ctenophora: two from Mnemiopsis leidyi and one from Pleurobrachia pileus. All ctenophore NRs contained a ligand-binding domain and grouped with NRs from the subfamily NR2A (HNF4. Surprisingly, all the ctenophore NRs lacked the highly conserved DNA-binding domain (DBD. NRs from Mnemiopsis were expressed in different regions of developing ctenophores. One was broadly expressed in the endoderm during gastrulation. The second was initially expressed in the ectoderm during gastrulation, in regions corresponding to the future tentacles; subsequent expression was restricted to the apical organ. Phylogenetic analyses of NRs from ctenophores, sponges, cnidarians, and a placozoan support the hypothesis that expansion of the superfamily occurred in a step-wise fashion, with initial radiations in NR family 2, followed by representatives of NR families 3, 6, and 1/4 originating prior to the appearance of the bilaterian ancestor. Conclusions Our study provides the first description of NRs from ctenophores, including the full complement from Mnemiopsis. Ctenophores have the least diverse NR complement of any animal phylum with representatives that cluster with only one subfamily (NR2A. Ctenophores and

A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K(+)/Na(+) Ratio, and Antioxidant Machinery.

Science.gov (United States)

Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K; Jha, Bhavanath

2016-01-01

About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na(+) ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

A SNARE-like superfamily protein SbSLSP from the halophyte Salicornia brachiata confers salt and drought tolerance by maintaining membrane stability, K+/Na+ ratio, and antioxidant machinery

Directory of Open Access Journals (Sweden)

Dinkar eSingh

2016-06-01

Full Text Available About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP, (Salicornia brachiata SNARE-like superfamily protein showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterised proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localisation studies indicated that the SbSLSP protein is mainly localised in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS. Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signalling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

Pathogenic Leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily

Science.gov (United States)

Matsunaga, James; Barocchi, Michele A.; Croda, Julio; Young, Tracy A.; Sanchez, Yolanda; Siqueira, Isadora; Bolin, Carole A.; Reis, Mitermayer G.; Riley, Lee W.; Haake, David A.; Ko, Albert I.

2005-01-01

Summary Proteins with bacterial immunoglobulin-like (Big) domains, such as the Yersinia pseudotuberculosis invasin and Escherichia coli intimin, are surface-expressed proteins that mediate host mammalian cell invasion or attachment. Here, we report the identification and characterization of a new family of Big domain proteins, referred to as Lig (leptospiral Ig-like) proteins, in pathogenic Leptospira. Screening of L. interrogans and L. kirschneri expression libraries with sera from leptospirosis patients identified 13 lambda phage clones that encode tandem repeats of the 90 amino acid Big domain. Two lig genes, designated ligA and ligB, and one pseudo-gene, ligC, were identified. The ligA and ligB genes encode amino-terminal lipoprotein signal peptides followed by 10 or 11 Big domain repeats and, in the case of ligB, a unique carboxy-terminal non-repeat domain. The organization of ligC is similar to that of ligB but contains mutations that disrupt the reading frame. The lig sequences are present in pathogenic but not saprophytic Leptospira species. LigA and LigB are expressed by a variety of virulent leptospiral strains. Loss of Lig protein and RNA transcript expression is correlated with the observed loss of virulence during culture attenuation of pathogenic strains. High-pressure freeze substitution followed by immunocytochemical electron microscopy confirmed that the Lig proteins were localized to the bacterial surface. Immunoblot studies with patient sera found that the Lig proteins are a major antigen recognized during the acute host infection. These observations demonstrate that the Lig proteins are a newly identified surface protein of pathogenic Leptospira, which by analogy to other bacterial immunoglobulin superfamily virulence factors, may play a role in host cell attachment and invasion during leptospiral pathogenesis. PMID:12890019

Extracellular Ribonuclease from Bacillus licheniformis (Balifase, a New Member of the N1/T1 RNase Superfamily

Directory of Open Access Journals (Sweden)

Yulia Sokurenko

2016-01-01

Full Text Available The N1/T1 RNase superfamily comprises enzymes with well-established antitumor effects, such as ribotoxins secreted by fungi, primarily by Aspergillus and Penicillium species, and bacterial RNase secreted by B. pumilus (binase and B. amyloliquefaciens (barnase. RNase is regarded as an alternative to classical chemotherapeutic agents due to its selective cytotoxicity towards tumor cells. New RNase with a high degree of structural similarity with binase (73% and barnase (74% was isolated and purified from Bacillus licheniformis (balifase, calculated molecular weight 12421.9 Da, pI 8.91. The protein sample with enzymatic activity of 1.5 × 106 units/A280 was obtained. The physicochemical properties of balifase are similar to those of barnase. However, in terms of its gene organization and promoter activity, balifase is closer to binase. The unique feature of balifase gene organization consists in the fact that genes of RNase and its inhibitor are located in one operon. Similarly to biosynthesis of binase, balifase synthesis is induced under phosphate starvation; however, in contrast to binase, balifase does not form dimers under natural conditions. We propose that the highest stability of balifase among analyzed RNase types allows the protein to retain its structure without oligomerization.

Kinetic and Structural Characterization of a Heterohexamer 4-Oxalocrotonate Tautomerase from Chloroflexus aurantiacus J-10-fl: Implications for Functional and Structural Diversity in the Tautomerase Superfamily

International Nuclear Information System (INIS)

Burks, Elizabeth A.; Fleming, Christopher D.; Mesecar, Andrew D.; Whitman, Christian P.; Pegan, Scott D.

2010-01-01

4-Oxalocrotonate tautomerase (4-OT) isozymes play prominent roles in the bacterial utilization of aromatic hydrocarbons as sole carbon sources. These enzymes catalyze the conversion of 2-hydroxy-2,4-hexadienedioate (or 2-hydroxymuconate) to 2-oxo-3-hexenedioate, where Pro-1 functions as a general base and shuttles a proton from the 2-hydroxyl group of the substrate to the C-5 position of the product. 4-OT, a homohexamer from Pseudomonas putida mt-2, is the most extensively studied 4-OT isozyme and the founding member of the tautomerase superfamily. A search of five thermophilic bacterial genomes identified a coded amino acid sequence in each that had been annotated as a tautomerase-like protein but lacked Pro-1. However, a nearby sequence has Pro-1, but the sequence is not annotated as a tautomerase-like protein. To characterize this group of proteins, two genes from Chloroflexus aurantiacus J-10-fl were cloned, and the corresponding proteins were expressed. Kinetic, biochemical, and X-ray structural analyses show that the two expressed proteins form a functional heterohexamer 4-OT (hh4-OT), composed of three αβ dimers. Like the P. putida enzyme, hh4-OT requires the amino-terminal proline and two arginines for the conversion of 2-hydroxymuconate to the product, implicating an analogous mechanism. In contrast to 4-OT, hh4-OT does not exhibit the low-level activity of another tautomerase superfamily member, the heterohexamer trans-3-chloroacrylic acid dehalogenase (CaaD). Characterization of hh4-OT enables functional assignment of the related enzymes, highlights the diverse ways the β-α-β building block can be assembled into an active enzyme, and provides further insight into the molecular basis of the low-level CaaD activity in 4-OT.

Oligomerisation status and evolutionary conservation of interfaces of protein structural domain superfamilies.

Science.gov (United States)

Sukhwal, Anshul; Sowdhamini, Ramanathan

2013-07-01

and its remote homologue-interacting partner pair. We found that, in exceptional cases, homologous proteins belonging to the same superfamily, but with remote sequence similarity, can share similar interfaces.

Association between discordant immunological response to highly active anti-retroviral therapy, regulatory T cell percentage, immune cell activation and very low-level viraemia in HIV-infected patients.

Science.gov (United States)

Saison, J; Ferry, T; Demaret, J; Maucort Boulch, D; Venet, F; Perpoint, T; Ader, F; Icard, V; Chidiac, C; Monneret, G

2014-06-01

The mechanisms sustaining the absence of complete immune recovery in HIV-infected patients upon long-term effective highly active anti-retroviral therapy (HAART) remain elusive. Immune activation, regulatory T cells (T(regs)) or very low-level viraemia (VLLV) have been alternatively suspected, but rarely investigated simultaneously. We performed a cross-sectional study in HIV-infected aviraemic subjects (mean duration of HAART: 12 years) to concomitantly assess parameters associated independently with inadequate immunological response. Patients were classified as complete immunological responders (cIR, n = 48) and inadequate immunological responders (iIR, n = 39), depending on the CD4(+) T cell count (> or response to long-term HAART, activation of CD4(+) and CD8(+) T cells, T(reg) percentages and very low-level viraemia. Causative interactions between T(regs) and CD4(+) T cells should now be explored prospectively in a large patients cohort. © 2014 British Society for Immunology.

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superfamily from higher plants

Science.gov (United States)

Rosenthal, Cindy; Mueller, Uwe; Panjikar, Santosh; Sun, Lianli; Ruppert, Martin; Zhao, Yu; Stöckigt, Joachim

2006-01-01

Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C2221 and diffract to 2.0 Å, with unit-cell parameters a = 58.9, b = 93.0, c = 143.4 Å. PMID:17142919

PpRT1: the first complete gypsy-like retrotransposon isolated in Pinus pinaster.

Science.gov (United States)

Rocheta, Margarida; Cordeiro, Jorge; Oliveira, M; Miguel, Célia

2007-02-01

We have isolated and characterized a complete retrotransposon sequence, named PpRT1, from the genome of Pinus pinaster. PpRT1 is 5,966 bp long and is closely related to IFG7 gypsy retrotransposon from Pinus radiata. The long terminal repeats (LTRs) have 333 bp each and show a 5.4% sequence divergence between them. In addition to the characteristic polypurine tract (PPT) and the primer binding site (PBS), PpRT1 carries internal regions with homology to retroviral genes gag and pol. The pol region contains sequence motifs related to the enzymes protease, reverse transcriptase, RNAseH and integrase in the same typical order known for Ty3/gypsy-like retrotransposons. PpRT1 was extended from an EST database sequence indicating that its transcription is occurring in pine tissues. Southern blot analyses indicate however, that PpRT1 is present in a unique or a low number of copies in the P. pinaster genome. The differences in nucleotide sequence found between PpRT1 and IFG7 may explain the strikingly different copy number in the two pine species genome. Based on the homologies observed when comparing LTR region among different gypsy elements we propose that the highly conserved LTR regions may be useful to amplify other retrotransposon sequences of the same or close retrotransposon family.

Conserved amino acid motifs from the novel Piv/MooV family of transposases and site-specific recombinases are required for catalysis of DNA inversion by Piv.

Science.gov (United States)

Tobiason, D M; Buchner, J M; Thiel, W H; Gernert, K M; Karls, A C

2001-02-01

Piv, a site-specific invertase from Moraxella lacunata, exhibits amino acid homology with the transposases of the IS110/IS492 family of insertion elements. The functions of conserved amino acid motifs that define this novel family of both transposases and site-specific recombinases (Piv/MooV family) were examined by mutagenesis of fully conserved amino acids within each motif in Piv. All Piv mutants altered in conserved residues were defective for in vivo inversion of the M. lacunata invertible DNA segment, but competent for in vivo binding to Piv DNA recognition sequences. Although the primary amino acid sequences of the Piv/MooV recombinases do not contain a conserved DDE motif, which defines the retroviral integrase/transposase (IN/Tnps) family, the predicted secondary structural elements of Piv align well with those of the IN/Tnps for which crystal structures have been determined. Molecular modelling of Piv based on these alignments predicts that E59, conserved as either E or D in the Piv/MooV family, forms a catalytic pocket with the conserved D9 and D101 residues. Analysis of Piv E59G confirms a role for E59 in catalysis of inversion. These results suggest that Piv and the related IS110/IS492 transposases mediate DNA recombination by a common mechanism involving a catalytic DED or DDD motif.

Syncytin-1, an endogenous retroviral protein, triggers the activation of CRP via TLR3 signal cascade in glial cells.

Science.gov (United States)

Wang, Xiuling; Liu, Zhongchun; Wang, Peigang; Li, Shan; Zeng, Jie; Tu, Xiaoning; Yan, Qiujin; Xiao, Zheman; Pan, Mengxian; Zhu, Fan

2018-01-01

Schizophrenia is a devastating psychiatric disorder that impacts on social functioning and quality of life, and there is accumulating evidence that inflammation is a potential pathogenic mechanism of schizophrenia. However, the mechanism of inflammation possibly occurred in schizophrenia has not been well understood. The endogenous retroviral protein syncytin-1 and inflammatory marker CRP are both abnormally expressed in schizophrenia patients. CRP is one of the markers of bacterial infection generally. Less clear is whether virus or viral protein can trigger the activation of CRP. Here, we detected a robust increase of the levels of syncytin-1 and CRP in schizophrenia patients, and displayed a positive correlation and marked consistency between expressions of syncytin-1 and CRP in schizophrenia patients. Furthermore, overexpression of syncytin-1 significantly elevated the levels of CRP, TLR3, and IL-6 in both human microglia and astrocytes. TLR3 deficiency impaired the expressions of CRP and IL-6 induced by syncytin-1. Importantly, we observed a cellular co-localization and a direct interaction between syncytin-1 and TLR3. Additionally, knockdown of IL-6 inhibited the syncytin-1-induced CRP expression. Thus, the totality of these results showed that viral protein syncytin-1 could trigger the activation of CRP, which might explain the elevated CRP in sterile inflammation and exhibit a novel mechanism for regulation of inflammation by syncytin-1 in schizophrenia. Copyright © 2017 Elsevier Inc. All rights reserved.

The FTO (fat mass and obesity associated gene codes for a novel member of the non-heme dioxygenase superfamily

Directory of Open Access Journals (Sweden)

Andrade-Navarro Miguel A

2007-11-01

Full Text Available Abstract Background Genetic variants in the FTO (fat mass and obesity associated gene have been associated with an increased risk of obesity. However, the function of its protein product has not been experimentally studied and previously reported sequence similarity analyses suggested the absence of homologs in existing protein databases. Here, we present the first detailed computational analysis of the sequence and predicted structure of the protein encoded by FTO. Results We performed a sequence similarity search using the human FTO protein as query and then generated a profile using the multiple sequence alignment of the homologous sequences. Profile-to-sequence and profile-to-profile based comparisons identified remote homologs of the non-heme dioxygenase family. Conclusion Our analysis suggests that human FTO is a member of the non-heme dioxygenase (Fe(II- and 2-oxoglutarate-dependent dioxygenases superfamily. Amino acid conservation patterns support this hypothesis and indicate that both 2-oxoglutarate and iron should be important for FTO function. This computational prediction of the function of FTO should suggest further steps for its experimental characterization and help to formulate hypothesis about the mechanisms by which it relates to obesity in humans.

5-Hydroxypyrido[2,3-b]pyrazin-6(5H)-one derivatives as novel dual inhibitors of HIV-1 reverse transcriptase-associated ribonuclease H and integrase.

Science.gov (United States)

Sun, Lin; Gao, Ping; Dong, Guanyu; Zhang, Xujie; Cheng, Xiqiang; Ding, Xiao; Wang, Xueshun; Daelemans, Dirk; De Clercq, Erik; Pannecouque, Christophe; Menéndez-Arias, Luis; Zhan, Peng; Liu, Xinyong

2018-06-18

We reported herein the design, synthesis and biological evaluation of a series of 5-hydroxypyrido[2,3-b]pyrazin-6(5H)-one derivatives as HIV-1 reverse transcriptase (RT) ribonuclease H (RNase H) inhibitors using a privileged structure-guided scaffold refining strategy. In view of the similarities between the pharmacophore model of RNase H and integrase (IN) inhibitors as well as their catalytic sites, we also performed IN inhibition assays. Notably, the majority of these derivatives inhibited RNase H and IN at micromolar concentrations. Among them, compound 7a exhibited similar inhibitory activity against RNase H and IN (IC 50 RNase H  = 1.77 μM, IC 50 IN  = 1.18 μM, ratio = 1.50). To the best of our knowledge, this is the first reported dual HIV-1 RNase H-IN inhibitor based on a 5-hydroxypyrido[2,3-b]pyrazin-6(5H)-one structure. Molecular modeling has been used to predict the binding mode of 7a in complex with the catalytic cores of HIV-1 RNase H and IN. Taken together these results strongly support the feasibility of developing HIV-1 dual inhibitors from analog-based optimization of divalent metal ion chelators. Recently, the identification of dual inhibitors proved to be a highly effective strategy for novel antivirals discovery. Therefore, these compounds appear to be useful leads that can be further modified to develop more valuable anti-HIV-1 molecules with suitable drug profiles. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Queratinocitos derivados de piel humana modificados por el vector retroviral FOCH 29-NeoR

Directory of Open Access Journals (Sweden)

Luz Marina Restrepo

2000-02-01

Full Text Available

En este protocolo se evaluará la eficiencia de la transducción mediada por el vector retroviral FOCH 29-NeoR derivado del virus de Friend; éste ha mostrado una alta eficiencia en la transducción, tanto de células madres hematopoyéticas como de otras líneas celulares. Se medirá su eficiencia de transducción en cultivos primarios de queratinocitos, derivados de biopsias de piel humana o de sobrantes de procedimientos quirúrgicos como circuncisiones, mastectomías y cirugía cosmética de pacientes que consultan el Hospital Universitario San Vicente de Paul, Hospital la María, la Clínica del Rosario y la Clínica León XIII.

Las muestras de piel se procesarán en un lapso no superior a 12 horas, se eliminará el exceso de dermis y tejido conectivo por digestión con dispasa (0.6-2.4 U/ml a 37°C durante 1 hora. Las muestras serán lavadas con PBS, antibiótico (penicilina + estreptomicina y se cortarán en fragmentos de 1-2 mm; después de 2-3 horas de digestión con tripsina-EDTA (0.25% las células serán resuspendidas en KGM (Medio de crecimiento para queratinocitos y se sembrarán a una concentración de 105 - 3x105 células por plato de 100 mm; se incubarán a 37°C, 5% CO2 con cambios de medio 2-3 veces por semana. Se harán subcultivos con el fin de expandirlos y congelar una parte de las

Superfamily of genes encoding G protein-coupled receptors in the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae).

Science.gov (United States)

Wu, S-F; Yu, H-Y; Jiang, T-T; Gao, C-F; Shen, J-L

2015-08-01

G protein-coupled receptors (GPCRs) are the largest and most versatile superfamily of cell membrane proteins, which mediate various physiological processes including reproduction, development and behaviour. The diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), is one of the most notorious insect pests, preferentially feeding on cruciferous plants. P. xylostella is not only one of the world's most widespread lepidopteran insects, but has also developed resistance to nearly all classes of insecticides. Although the mechanisms of insecticide resistance have been studied extensively in many insect species, few investigations have been carried out on GPCRs in P. xylostella. In the present study, we identified 95 putative GPCRs in the P. xylostella genome. The identified GPCRs were compared with their homologues in Bombyx mori and Drosophila melanogaster. Our results suggest that GPCRs in different insect species may have evolved by a birth-and-death process. One of the differences among compared insects is the duplication of short neuropeptide F receptor and adipokinetic hormone receptors in P. xylostella and B. mori. Another divergence is the decrease in quantity and diversity of the stress-tolerance gene, Mth, in P. xylostella. The evolution by the birth-and-death process is probably involved in adaptation to the feeding behaviour, reproduction and stress responses of P. xylostella. Some of the genes identified in the present study could be potential targets for the development of novel pesticides. © 2015 The Royal Entomological Society.

Exploring the role of cellular homologous of the 30K-superfamily of plant virus movement proteins.

Science.gov (United States)

Carrasco, José L; Sánchez-Navarro, Jesús A; Elena, Santiago F

2018-02-21

Genes orthologous to the 30K-superfamily of movement proteins (MP) from plant viruses have been recently discovered by bioinformatics analyses as integrated elements in the genome of most vascular plants. However, their functional relevance for plants is still unclear. Here, we undertake some preliminary steps into the functional characterization of one of these putative MP genes found in Arabidopsis thaliana. We found that the AtMP gene is expressed at different stages of the plant development, with accumulation being highest in flowers but lowest in mature siliques. We also found down-regulation of the gene may result in a small delay in plant development and in an exacerbation of the negative effect of salinity in germination efficiency. We have also explored whether changes in expression of the endogenous AtMP have any effect on susceptibility to infection with several viruses, and found that the infectivity of tobacco rattle tobravirus was strongly dependent on the expression of the endogenous AtMP. Finally, we have cloned the endogenous MP from four different plant species into an expression vector that allows for specifically assessing their activity as cell-to-cell movement proteins and have shown that though some may still retain the ancestral activity, they do so in a quite inefficient manner, thus suggesting they have acquired a novel function during adaptation to the host genome. Copyright © 2018 Elsevier B.V. All rights reserved.

Hypothesis for heritable, anti-viral immunity in crustaceans and insects

Directory of Open Access Journals (Sweden)

Flegel Timothy W

2009-09-01

Full Text Available Abstract Background It is known that crustaceans and insects can persistently carry one or more viral pathogens at low levels, without signs of disease. They may transmit them to their offspring or to naïve individuals, often with lethal consequences. The underlying molecular mechanisms have not been elucidated, but the process has been called viral accommodation. Since tolerance to one virus does not confer tolerance to another, tolerance is pathogen-specific, so the requirement for a specific pathogen response mechanism (memory was included in the original viral accommodation concept. Later, it was hypothesized that specific responses were based on the presence of viruses in persistent infections. However, recent developments suggest that specific responses may be based on viral sequences inserted into the host genome. Presentation of the hypothesis Non-retroviral fragments of both RNA and DNA viruses have been found in insect and crustacean genomes. In addition, reverse-transcriptase (RT and integrase (IN sequences are also common in their genomes. It is hypothesized that shrimp and other arthropods use these RT to recognize "foreign" mRNA of both RNA and DNA viruses and use the integrases (IN to randomly insert short cDNA sequences into their genomes. By chance, some of these sequences result in production of immunospecific RNA (imRNA capable of stimulating RNAi that suppresses viral propagation. Individuals with protective inserts would pass these on to the next generation, together with similar protective inserts for other viruses that could be amalgamated rapidly in individual offspring by random assortment of chromosomes. The most successful individuals would be environmentally selected from billions of offspring. Conclusion This hypothesis for immunity based on an imRNA generation mechanism fits with the general principle of invertebrate immunity based on a non-host, "pattern recognition" process. If proven correct, understanding the

Mycobacterium smegmatis SftH exemplifies a distinctive clade of superfamily II DNA-dependent ATPases with 3' to 5' translocase and helicase activities.

Science.gov (United States)

Yakovleva, Lyudmila; Shuman, Stewart

2012-08-01

Bacterial DNA helicases are nucleic acid-dependent NTPases that play important roles in DNA replication, recombination and repair. We are interested in the DNA helicases of Mycobacteria, a genus of the phylum Actinobacteria, which includes the human pathogen Mycobacterium tuberculosis and its avirulent relative Mycobacterium smegmatis. Here, we identify and characterize M. smegmatis SftH, a superfamily II helicase with a distinctive domain structure, comprising an N-terminal NTPase domain and a C-terminal DUF1998 domain (containing a putative tetracysteine metal-binding motif). We show that SftH is a monomeric DNA-dependent ATPase/dATPase that translocates 3' to 5' on single-stranded DNA and has 3' to 5' helicase activity. SftH homologs are found in bacteria representing 12 different phyla, being especially prevalent in Actinobacteria (including M. tuberculosis). SftH homologs are evident in more than 30 genera of Archaea. Among eukarya, SftH homologs are present in plants and fungi.

GH97 is a new family of glycoside hydrolases, which is related to the α-galactosidase superfamily

Directory of Open Access Journals (Sweden)

Naumoff Daniil G

2005-08-01

Full Text Available Abstract Background As a rule, about 1% of genes in a given genome encode glycoside hydrolases and their homologues. On the basis of sequence similarity they have been grouped into more than ninety GH families during the last 15 years. The GH97 family has been established very recently and initially included only 18 bacterial proteins. However, the evolutionary relationship of the genes encoding proteins of this family remains unclear, as well as their distribution among main groups of the living organisms. Results The extensive search of the current databases allowed us to double the number of GH97 family proteins. Five subfamilies were distinguished on the basis of pairwise sequence comparison and phylogenetic analysis. Iterative sequence analysis revealed the relationship of the GH97 family with the GH27, GH31, and GH36 families of glycosidases, which belong to the α-galactosidase superfamily, as well as a more distant relationship with some other glycosidase families (GH13 and GH20. Conclusion The results of this study show an unexpected sequence similarity of GH97 family proteins with glycoside hydrolases from several other families, that have (β/α8-barrel fold of the catalytic domain and a retaining mechanism of the glycoside bond hydrolysis. These data suggest a common evolutionary origin of glycosidases representing different families and clans.

Identification of the bacteria-binding peptide domain on salivary agglutinin (gp-340/DMBT1), a member of the scavenger receptor cysteine-rich superfamily

DEFF Research Database (Denmark)

Bikker, Floris J; Ligtenberg, Antoon J M; Nazmi, Kamran

2002-01-01

Salivary agglutinin is encoded by DMBT1 and identical to gp-340, a member of the scavenger receptor cysteine-rich (SRCR) superfamily. Salivary agglutinin/DMBT1 is known for its Streptococcus mutans agglutinating properties. This 300-400 kDa glycoprotein is composed of conserved peptide motifs: 14...... containing exclusively SRCR and SID domains that binds to S. mutans. To define more closely the S. mutans-binding domain, consensus-based peptides of the SRCR domains and SIDs were designed and synthesized. Only one of the SRCR peptides, designated SRCRP2, and none of the SID peptides bound to S. mutans....... Strikingly, this peptide was also able to induce agglutination of S. mutans and a number of other bacteria. The repeated presence of this peptide in the native molecule endows agglutinin/DMBT1 with a general bacterial binding feature with a multivalent character. Moreover, our studies demonstrate...

[Isolation and identification of the temperate bacteriophage from isolated strains of Streptococcus suis serotype 2].

Science.gov (United States)

Ma, Yuling; Lu, Chengping; Fan, Hongjie

2008-04-01

A PCR assay was developed to study the distributional characteristics of phage integrase gene in Streptococcus suis serotype 2 (SS2). A 323bp distinct DNA target can be amplified in 25 strains of virulent SS2, while can not be amplified in avirulent strain T15, 5 strains of other serotypes (SS1, SS7, SS9) and strains of group C Streptococcus strains from pigs, which suggested that the phage integrase gene may be related to the pathogenicity of SS2 and can be consider as a detection factor of the virulent gene of SS2. The sequencing and restriction endonuclease analysis of the PCR products were also done. Comparisons between the sequences of phage integrase gene with that of SS2 strain, showed a high homology with SS2 China strains 98HAH33, 05ZYH33 and North American strain 89-1591. Complete cell lysis was observed with SS2 virulent strains but not with avirulent strain T15 after the induction by mitomycin C. Electron microscopy analysis of the lysate from SS2 virulent strains HA9801 and ZY05719 revealed the presence of phage particles. The induced phage, named SS2-HA and SS2-ZY, both have a small isometric nucleocapsid approximately 50 nm in diameter and have no tail and is therefore a member of the Tectiviridae family. The phage integrase gene sequence of phage SS2-HA and SS2-ZY shared high homologue identities with virulent SS2 strains, which suggested that the phage integrase gene of SS2 has high specify. The temperate phage and phage integrase gene can only detected from SS2 virulent strains but not from avirulent strain, and the detection of phage integrase gene was related to the virulence-associate factors of SS2, such as the muramidase-released protein gene (mrp), which suggested that the temperate phage of SS2 may be related to the pathogenicity of SS2.

Non-adherence to anti-retroviral therapy among HIV infected adults in Mon State of Myanmar

Directory of Open Access Journals (Sweden)

Win Lei Aye

2017-05-01

Full Text Available Abstract Background The provision of Anti-Retroviral Therapy (ART was started in Myanmar in 2005 in collaboration with the National AIDS Program and the private sector. Successful clinical management of HIV-infected patients is subject to optimal adherence. The aim of the study was to determine the prevalence of adherence to ART and identify factors associated with non-adherence to ART among HIV infected adults registered in a private sector setting in Mon State, Myanmar. Methods This cross-sectional study was conducted with adults living with HIV receiving ART at an HIV outpatient clinic between April and May 2016. A total of three hundred People Living with HIV(PLHIV were interviewed using a pretested and structured questionnaire. The 30 days Visual Analog Scale (VAS adherence instrument was used to assess the level of adherence. Multivariable logistic regression analysis was used to determine factors associated with non-adherence to ART. Results Among 300 patients (male 37.7% and female 62.3%, with a mean age of 41.3 years, standard deviation 8.7, 84% reported ≥95% adherence to ART in the past month. Among 16% of those reporting non-adherence, major reasons for skipping the medication were being busy (23%, being away from home (17.7% and being forgetful (12.3%. In multivariable logistic rgeression, low behavioural skills on ART adherence (OR = 0.31, 95% CI: 0.10-0.94, tobacco use (OR = 3.22, 95% CI:1.28-8.12, having disclosed their HIV status (OR = 0.07, 95% CI: 0.01-0.69, having a partner who was not on ART (OR = 4.25, 95% CI: 1.70-10.64 and among men, having erectile dysfunction (OR = 15.14, 95% CI: 1.41-162.66 were significant associated with ART non-adherence. Conclusion Non-adherence to ART was associated with individual moderating factors and behavioral skills. Priority measures such as addressing risk behaviour and behavioural change communication tailored to individual patients’ lifestyles requires comprehensive

Non-adherence to anti-retroviral therapy among HIV infected adults in Mon State of Myanmar.

Science.gov (United States)

Aye, Win Lei; Puckpinyo, Apa; Peltzer, Karl

2017-05-05

The provision of Anti-Retroviral Therapy (ART) was started in Myanmar in 2005 in collaboration with the National AIDS Program and the private sector. Successful clinical management of HIV-infected patients is subject to optimal adherence. The aim of the study was to determine the prevalence of adherence to ART and identify factors associated with non-adherence to ART among HIV infected adults registered in a private sector setting in Mon State, Myanmar. This cross-sectional study was conducted with adults living with HIV receiving ART at an HIV outpatient clinic between April and May 2016. A total of three hundred People Living with HIV(PLHIV) were interviewed using a pretested and structured questionnaire. The 30 days Visual Analog Scale (VAS) adherence instrument was used to assess the level of adherence. Multivariable logistic regression analysis was used to determine factors associated with non-adherence to ART. Among 300 patients (male 37.7% and female 62.3%, with a mean age of 41.3 years, standard deviation 8.7), 84% reported ≥95% adherence to ART in the past month. Among 16% of those reporting non-adherence, major reasons for skipping the medication were being busy (23%), being away from home (17.7%) and being forgetful (12.3%). In multivariable logistic rgeression, low behavioural skills on ART adherence (OR = 0.31, 95% CI: 0.10-0.94), tobacco use (OR = 3.22, 95% CI:1.28-8.12), having disclosed their HIV status (OR = 0.07, 95% CI: 0.01-0.69), having a partner who was not on ART (OR = 4.25, 95% CI: 1.70-10.64) and among men, having erectile dysfunction (OR = 15.14, 95% CI: 1.41-162.66) were significant associated with ART non-adherence. Non-adherence to ART was associated with individual moderating factors and behavioral skills. Priority measures such as addressing risk behaviour and behavioural change communication tailored to individual patients' lifestyles requires comprehensive interventions to improve adherence.

Evaluation of the effect of short-term treatment with the integrase inhibitor raltegravir (Isentress) on the course of progressive feline leukemia virus infection.

Science.gov (United States)

Boesch, Andrea; Cattori, Valentino; Riond, Barbara; Willi, Barbara; Meli, Marina L; Rentsch, Katharina M; Hosie, Margaret J; Hofmann-Lehmann, Regina; Lutz, Hans

2015-02-25

Cats persistently infected with the gammaretrovirus feline leukemia virus (FeLV) are at risk to die within months to years from FeLV-associated disease, such as immunosuppression, anemia or lymphoma/leukemia. The integrase inhibitor raltegravir has been demonstrated to reduce FeLV replication in vitro. The aim of the present study was to investigate raltegravir in vivo for its safety and efficacy to suppress FeLV replication. The safety was tested in three naïve specified pathogen-free (SPF) cats during a 15 weeks treatment period (initially 20mg then 40mg orally b.i.d.). No adverse effects were noted. The efficacy was tested in seven persistently FeLV-infected SPF cats attained from 18 cats experimentally exposed to FeLV-A/Glasgow-1. The seven cats were treated during nine weeks (40mg then 80mg b.i.d.). Raltegravir was well tolerated even at the higher dose. A significant decrease in plasma viral RNA loads (∼5×) was found; however, after treatment termination a rebound effect was observed. Only one cat developed anti-FeLV antibodies and viral RNA loads remained decreased after treatment termination. Of note, one of the untreated FeLV-A infected cats developed fatal FeLV-C associated anemia within 5 weeks of FeLV-A infection. Moreover, progressive FeLV infection was associated with significantly lower enFeLV loads prior to infection supporting that FeLV susceptibility may be related to the genetic background of the cat. Overall, our data demonstrate the ability of raltegravir to reduce viral replication also in vivo. However, no complete control of viremia was achieved. Further investigations are needed to find an optimized treatment against FeLV. (250 words). Copyright © 2014 Elsevier B.V. All rights reserved.

Supporting children to adhere to anti-retroviral therapy in urban Malawi: multi method insights

Directory of Open Access Journals (Sweden)

Phiri Sam

2009-07-01

Full Text Available Abstract Background Ensuring good adherence is critical to the success of anti-retroviral treatment (ART. However, in resource-poor contexts, where paediatric HIV burden is high there has been limited progress in developing or adapting tools to support adherence for HIV-infected children on ART and their caregivers. We conducted formative research to assess children's adherence and to explore the knowledge, perceptions and attitudes of caregivers towards children's treatment. Methods All children starting ART between September 2002 and January 2004 (when ART was at cost in Malawi were observed for at least 6 months on ART. Their adherence was assessed quantitatively by asking caregivers of children about missed ART doses during the previous 3 days at monthly visits. Attendance to clinic appointments was also monitored. In June and July 2004, four focus group discussions, each with 6 to 8 caregivers, and 5 critical incident narratives were conducted to provide complementary contextual data on caregivers' experiences on the challenges to and opportunities of paediatric ART adherence. Results We followed prospectively 47 children who started ART between 8 months and 12 years of age over a median time on ART of 33 weeks (2–91 weeks. 72% (34/47 never missed a single dose according to caregivers' report and 82% (327/401 of clinic visits were either as scheduled, or before or within 1 week after the scheduled appointment. Caregivers were generally knowledgeable about ART and motivated to support children to adhere to treatment despite facing multiple challenges. Caregivers were particularly motivated by seeing children begin to get better; but faced challenges in meeting the costs of medicine and transport, waiting times in clinic, stock outs and remembering to support children to adhere in the face of multiple responsibilities. Conclusion In the era of rapid scale-up of treatment for children there is need for holistic support strategies that focus

Understanding the -C-X1-X2-C- motif in the active site of the thioredoxin superfamily: E. coli DsbA and its mutants as a model system.

Science.gov (United States)

Karshikoff, Andrey; Nilsson, Lennart; Foloppe, Nicolas

2013-08-27

E. coli DsbA is an intensively studied enzyme of the thioredoxin superfamily of thiol-disulfide oxidoreductases. DsbA catalyzes the disulfide bond formation and folding of proteins in the bacterial periplasm. DsbA and its mutants have highlighted the strong and puzzling influence of the -C-X1-X2-C- active site variants, found across the thioredoxin superfamily, on the ionization and redox properties of this site. However, the interpretation of these observations remains wanting, largely due to a dearth of structural information. Here, molecular dynamics simulations are used to provide extensive information on the structure and dynamics of reduced -C30-X31-X32-C33- motifs in wild type DsbA and 13 of its mutants. These simulations are combined with calculations of the pK of H32 and of the very low pK of the catalytic cysteine C30. In wild type DsbA, the titrations of C30 and H32 are shown to be coupled; the protonation states and dynamics of H32 are examined. The thiolate of C30 is stabilized by hydrogen bonds with the protein. Modulation of these hydrogen bonds by alteration of residue X32 has the greatest impact on the pK of C30, which rationalizes its higher pK in thioredoxin and tryparedoxin. Because of structural constrains, residue X31 has only an indirect and weak influence on the pK of C30. The dynamics of C30 is clearly related to its stabilizing interactions and pK value. Although relatively small differences between pKs were not reproduced in the calculations, the major trends are explained, adding new insights to our understanding of enzymes in this family.

Discovery of a distinct superfamily of Kunitz-type toxin (KTT from tarantulas.

Directory of Open Access Journals (Sweden)

Chun-Hua Yuan

Full Text Available BACKGROUND: Kuntiz-type toxins (KTTs have been found in the venom of animals such as snake, cone snail and sea anemone. The main ancestral function of Kunitz-type proteins was the inhibition of a diverse array of serine proteases, while toxic activities (such as ion-channel blocking were developed under a variety of Darwinian selection pressures. How new functions were grafted onto an old protein scaffold and what effect Darwinian selection pressures had on KTT evolution remains a puzzle. PRINCIPAL FINDINGS: Here we report the presence of a new superfamily of ktts in spiders (TARANTULAS: Ornithoctonus huwena and Ornithoctonus hainana, which share low sequence similarity to known KTTs and is clustered in a distinct clade in the phylogenetic tree of KTT evolution. The representative molecule of spider KTTs, HWTX-XI, purified from the venom of O. huwena, is a bi-functional protein which is a very potent trypsin inhibitor (about 30-fold more strong than BPTI as well as a weak Kv1.1 potassium channel blocker. Structural analysis of HWTX-XI in 3-D by NMR together with comparative function analysis of 18 expressed mutants of this toxin revealed two separate sites, corresponding to these two activities, located on the two ends of the cone-shape molecule of HWTX-XI. Comparison of non-synonymous/synonymous mutation ratios (omega for each site in spider and snake KTTs, as well as PBTI like body Kunitz proteins revealed high Darwinian selection pressure on the binding sites for Kv channels and serine proteases in snake, while only on the proteases in spider and none detected in body proteins, suggesting different rates and patterns of evolution among them. The results also revealed a series of key events in the history of spider KTT evolution, including the formation of a novel KTT family (named sub-Kuntiz-type toxins derived from the ancestral native KTTs with the loss of the second disulfide bridge accompanied by several dramatic sequence modifications

Geometrically and conformationally restrained cinnamoyl compounds as inhibitors of HIV-1 integrase: synthesis, biological evaluation, and molecular modeling.

Science.gov (United States)

Artico, M; Di Santo, R; Costi, R; Novellino, E; Greco, G; Massa, S; Tramontano, E; Marongiu, M E; De Montis, A; La Colla, P

1998-10-08

Various cinnammoyl-based structures were synthesized and tested in enzyme assays as inhibitors of the HIV-1 integrase (IN). The majority of compounds were designed as geometrically or conformationally constrained analogues of caffeic acid phenethyl ester (CAPE) and were characterized by a syn disposition of the carbonyl group with respect to the vinylic double bond. Since the cinnamoyl moiety present in flavones such as quercetin (inactive on HIV-1-infected cells) is frozen in an anti arrangement, it was hoped that fixing our compounds in a syn disposition could favor anti-HIV-1 activity in cell-based assays. Geometrical and conformational properties of the designed compounds were taken into account through analysis of X-ray structures available from the Cambridge Structural Database. The polyhydroxylated analogues were prepared by reacting 3,4-bis(tetrahydropyran-2-yloxy)benzaldehyde with various compounds having active methylene groups such as 2-propanone, cyclopentanone, cyclohexanone, 1,3-diacetylbenzene, 2, 4-dihydroxyacetophenone, 2,3-dihydro-1-indanone, 2,3-dihydro-1, 3-indandione, and others. While active against both 3'-processing and strand-transfer reactions, the new compounds, curcumin included, failed to inhibit the HIV-1 multiplication in acutely infected MT-4 cells. Nevertheless, they specifically inhibited the enzymatic reactions associated with IN, being totally inactive against other viral (HIV-1 reverse transcriptase) and cellular (RNA polymerase II) nucleic acid-processing enzymes. On the other hand, title compounds were endowed with remarkable antiproliferative activity, whose potency correlated neither with the presence of catechols (possible source of reactive quinones) nor with inhibition of topoisomerases. The SARs developed for our compounds led to novel findings concerning the molecular determinants of IN inhibitory activity within the class of cinnamoyl-based structures. We hypothesize that these compounds bind to IN featuring the

Associations between HIV, highly active anti-retroviral therapy, and hypertensive disorders of pregnancy among maternal deaths in South Africa 2011-2013.

Science.gov (United States)

Sebitloane, Hannah M; Moodley, Jagidesa; Sartorius, Benn

2017-02-01

To explore potential relationships between HIV and highly active anti-retroviral therapy (HAART), and hypertensive disorders of pregnancy (HDP). A retrospective secondary analysis of maternal-deaths data from the 2011-2013 Saving Mothers Report from South Africa. The incidence of HIV infection amongst individuals who died owing to HDP was determined and comparisons were made based on HIV status and the use of HAART. Among 4452 maternal deaths recorded in the Saving Mothers report, a lower risk of a maternal deaths being due to HDP was observed among women who had HIV infections compared with women who did not have HIV (relative risk [RR] 0.57, 95% confidence interval [CI] 0.51-0.64). Further, reduced odds of death being due to HDP were recorded among women with AIDS not undergoing HAART compared with women with HIV who did not require treatment (RR 0.42, 95% CI 0.3-0.58). Notably, among all women with AIDS, a greater risk of death due to HDP was demonstrated among those who received HAART compared with those who did not (RR 1.15, 95% CI 1.02-1.29). HIV and AIDS were associated with a decreased risk of HDP being the primary cause of death; the use of HAART increased this risk. © 2016 International Federation of Gynecology and Obstetrics.

Incorporation of aptamers in the terminal loop of shRNAs yields an effective and novel combinatorial targeting strategy.

Science.gov (United States)

Pang, Ka Ming; Castanotto, Daniela; Li, Haitang; Scherer, Lisa; Rossi, John J

2018-01-09

Gene therapy by engineering patient's own blood cells to confer HIV resistance can potentially lead to a functional cure for AIDS. Toward this goal, we have previously developed an anti-HIV lentivirus vector that deploys a combination of shRNA, ribozyme and RNA decoy. To further improve this therapeutic vector against viral escape, we sought an additional reagent to target HIV integrase. Here, we report the development of a new strategy for selection and expression of aptamer for gene therapy. We developed a SELEX protocol (multi-tag SELEX) for selecting RNA aptamers against proteins with low solubility or stability, such as integrase. More importantly, we expressed these aptamers in vivo by incorporating them in the terminal loop of shRNAs. This novel strategy allowed efficient expression of the shRNA-aptamer fusions that targeted RNAs and proteins simultaneously. Expressed shRNA-aptamer fusions targeting HIV integrase or reverse transcriptase inhibited HIV replication in cell cultures. Viral inhibition was further enhanced by combining an anti-integrase aptamer with an anti-HIV Tat-Rev shRNA. This construct exhibited efficacy comparable to that of integrase inhibitor Raltegravir. Our strategy for the selection and expression of RNA aptamers can potentially extend to other gene therapy applications. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Gene Expression in Class 2 Integrons Is SOS-Independent and Involves Two Pc Promoters.

Science.gov (United States)

Jové, Thomas; Da Re, Sandra; Tabesse, Aurore; Gassama-Sow, Amy; Ploy, Marie-Cécile

2017-01-01

Integrons are powerful bacterial genetic elements that permit the expression and dissemination of antibiotic-resistance gene cassettes. They contain a promoter Pc that allows the expression of gene cassettes captured through site-specific recombination catalyzed by IntI, the integron-encoded integrase. Class 1 and 2 integrons are found in both clinical and environmental settings. The regulation of intI and of Pc promoters has been extensively studied in class 1 integrons and the regulatory role of the SOS response on intI expression has been shown. Here we investigated class 2 integrons. We characterized the P intI2 promoter and showed that intI2 expression is not regulated via the SOS response. We also showed that, unlike class 1 integrons, class 2 integrons possess not one but two active Pc promoters that are located within the attI2 region that seem to contribute equally to gene cassette expression. Class 2 integrons mostly encode an inactive truncated integrase, but the rare class 2 integrons that encode an active integrase are associated with less efficient Pc2 promoter variants. We propose an evolutionary model for class 2 integrons in which the absence of repression of the integrase gene expression led to mutations resulting in either inactive integrase or Pc variants of weaker activity, thereby reducing the potential fitness cost of these integrons.

1,4-Bis(5-(naphthalen-1-yl)thiophen-2-yl)naphthalene, a small molecule, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular Lens epithelium-derived growth factor.

Science.gov (United States)

Gu, Wan-gang; Ip, Denis Tsz-Ming; Liu, Si-jie; Chan, Joseph H; Wang, Yan; Zhang, Xuan; Zheng, Yong-tang; Wan, David Chi-Cheong

2014-04-25

Translocation of viral integrase (IN) into the nucleus is a critical precondition of integration during the life cycle of HIV, a causative agent of Acquired Immunodeficiency Syndromes (AIDS). As the first discovered cellular factor to interact with IN, Lens epithelium-derived growth factor (LEDGF/p75) plays an important role in the process of integration. Disruption of the LEDGF/p75-IN interaction has provided a great interest for anti-HIV agent discovery. In this work, we reported that one small molecular compound, 1,4-bis(5-(naphthalen-1-yl)thiophen-2-yl)naphthalene(Compound 15), potently inhibit the IN-LEDGF/p75 interaction and affect the HIV-1 IN nuclear distribution at 1 μM. The putative binding mode of Compound 15 was constructed by a molecular docking simulation to provide structural insights into the ligand-binding mechanism. Compound 15 suppressed viral replication by measuring p24 antigen production in HIV-1IIIB acute infected C8166 cells with EC50 value of 11.19 μM. Compound 15 might supply useful structural information for further anti-HIV agent discovery. Copyright © 2014. Published by Elsevier Ireland Ltd.

Effect of Micronutrient and Probiotic Fortified Yogurt on Immune-Function of Anti-Retroviral Therapy Naive HIV Patients  

Directory of Open Access Journals (Sweden)

J. Dik F. Habbema

2011-10-01

Full Text Available Background: Micronutrient supplementation has been shown to reduce the progression of HIV but does not have an effect on the intestinal barrier or the intestinal microbiota of HIV patients. Studies have suggested that probiotics could potentially complement micronutrients in preserving the immune-function of HIV patients. Objective: Assess the impact of micronutrient supplemented probiotic yogurt on the immune function of HIV patients. Design: We performed a randomized, double blind, controlled trial with CD4 count as primary outcome among HIV patients naïve to anti-retroviral treatment. Secondary outcomes included hematological parameters, incidence of diarrhea and clinical symptoms. A total of 112 HIV patients were randomized to receive a micronutrient fortified yogurt with (n = 55 or without additional probiotic Lactobacillus rhamnosus GR-1 (n = 57 for four weeks. Results: An average decline in CD4 count of −70 cells/μL (95% CI: −154 to −15 was observed in the micronutrient, probiotic group versus a decrease of −63 cells/μL (95% CI: −157 to −30 in the micronutrient control group (p = 0.9. Additional probiotic supplementation was well tolerated and not associated with adverse events. No difference between groups was detected in incidence of diarrhea or clinical symptoms. An improvement of hemoglobin levels was observed for all subjects, based upon a mean difference from baseline of 1.4 g/L (SD = 6 (p = 0.02. Conclusion: The addition of probiotics to a micronutrient fortified yogurt was well tolerated by HIV patients but was not associated with a further increase in CD4 count after one month.

The short mRNA isoform of the immunoglobulin superfamily, member 1 gene encodes an intracellular glycoprotein.

Directory of Open Access Journals (Sweden)

Ying Wang

Full Text Available Mutations in the immunoglobulin superfamily, member 1 gene (IGSF1/Igsf1 cause an X-linked form of central hypothyroidism. The canonical form of IGSF1 is a transmembrane glycoprotein with 12 immunoglobulin (Ig loops. The protein is co-translationally cleaved into two sub-domains. The carboxyl-terminal domain (CTD, which contains the last 7 Ig loops, is trafficked to the plasma membrane. Most pathogenic mutations in IGSF1 map to the portion of the gene encoding the CTD. IGSF1/Igsf1 encodes a variety of transcripts. A little studied, but abundant splice variant encodes a truncated form of the protein, predicted to contain the first 2 Ig loops of the full-length IGSF1. The protein (hereafter referred to as IGSF1 isoform 2 or IGSF1-2 is likely retained in most individuals with IGSF1 mutations. Here, we characterized basic biochemical properties of the protein as a foray into understanding its potential function. IGSF1-2, like the IGSF1-CTD, is a glycoprotein. In both mouse and rat, the protein is N-glycosylated at a single asparagine residue in the first Ig loop. Contrary to earlier predictions, neither the murine nor rat IGSF1-2 is secreted from heterologous or homologous cells. In addition, neither protein associates with the plasma membrane. Rather, IGSF1-2 appears to be retained in the endoplasmic reticulum. Whether the protein plays intracellular functions or is trafficked through the secretory pathway under certain physiologic or pathophysiologic conditions has yet to be determined.

Concerted and nonconcerted evolution of the Hsp70 gene superfamily in two sibling species of nematodes.

Science.gov (United States)

Nikolaidis, Nikolas; Nei, Masatoshi

2004-03-01

We have identified the Hsp70 gene superfamily of the nematode Caenorhabditis briggsae and investigated the evolution of these genes in comparison with Hsp70 genes from C. elegans, Drosophila, and yeast. The Hsp70 genes are classified into three monophyletic groups according to their subcellular localization, namely, cytoplasm (CYT), endoplasmic reticulum (ER), and mitochondria (MT). The Hsp110 genes can be classified into the polyphyletic CYT group and the monophyletic ER group. The different Hsp70 and Hsp110 groups appeared to evolve following the model of divergent evolution. This model can also explain the evolution of the ER and MT genes. On the other hand, the CYT genes are divided into heat-inducible and constitutively expressed genes. The constitutively expressed genes have evolved more or less following the birth-and-death process, and the rates of gene birth and gene death are different between the two nematode species. By contrast, some heat-inducible genes show an intraspecies phylogenetic clustering. This suggests that they are subject to sequence homogenization resulting from gene conversion-like events. In addition, the heat-inducible genes show high levels of sequence conservation in both intra-species and inter-species comparisons, and in most cases, amino acid sequence similarity is higher than nucleotide sequence similarity. This indicates that purifying selection also plays an important role in maintaining high sequence similarity among paralogous Hsp70 genes. Therefore, we suggest that the CYT heat-inducible genes have been subjected to a combination of purifying selection, birth-and-death process, and gene conversion-like events.

Drosophila Model for the Analysis of Genesis of LIM-kinase 1-Dependent Williams-Beuren Syndrome Cognitive Phenotypes: INDELs, Transposable Elements of the Tc1/Mariner Superfamily and MicroRNAs

Directory of Open Access Journals (Sweden)

Elena V. Savvateeva-Popova

2017-09-01

Full Text Available Genomic disorders, the syndromes with multiple manifestations, may occur sporadically due to unequal recombination in chromosomal regions with specific architecture. Therefore, each patient may carry an individual structural variant of DNA sequence (SV with small insertions and deletions (INDELs sometimes less than 10 bp. The transposable elements of the Tc1/mariner superfamily are often associated with hotspots for homologous recombination involved in human genetic disorders, such as Williams Beuren Syndromes (WBS with LIM-kinase 1-dependent cognitive defects. The Drosophila melanogaster mutant agnts3 has unusual architecture of the agnostic locus harboring LIMK1: it is a hotspot of chromosome breaks, ectopic contacts, underreplication, and recombination. Here, we present the analysis of LIMK1-containing locus sequencing data in agnts3 and three D. melanogaster wild-type strains—Canton-S, Berlin, and Oregon-R. We found multiple strain-specific SVs, namely, single base changes and small INDEls. The specific feature of agnts3 is 28 bp A/T-rich insertion in intron 1 of LIMK1 and the insertion of mobile S-element from Tc1/mariner superfamily residing ~460 bp downstream LIMK1 3′UTR. Neither of SVs leads to amino acid substitutions in agnts3 LIMK1. However, they apparently affect the nucleosome distribution, non-canonical DNA structure formation and transcriptional factors binding. Interestingly, the overall expression of miRNAs including the biomarkers for human neurological diseases, is drastically reduced in agnts3 relative to the wild-type strains. Thus, LIMK1 DNA structure per se, as well as the pronounced changes in total miRNAs profile, probably lead to LIMK1 dysregulation and complex behavioral dysfunctions observed in agnts3 making this mutant a simple plausible Drosophila model for WBS.

CACTA-superfamily transposable element is inserted in MYB transcription factor gene of soybean line producing variegated seeds.

Science.gov (United States)

Yan, Fan; Di, Shaokang; Takahashi, Ryoji

2015-08-01

The R gene of soybean, presumably encoding a MYB transcription factor, controls seed coat color. The gene consists of multiple alleles, R (black), r-m (black spots and (or) concentric streaks on brown seed), and r (brown seed). This study was conducted to determine the structure of the MYB transcription factor gene in a near-isogenic line (NIL) having r-m allele. PCR amplification of a fragment of the candidate gene Glyma.09G235100 generated a fragment of about 1 kb in the soybean cultivar Clark, whereas a fragment of about 14 kb in addition to fragments of 1 and 1.4 kb were produced in L72-2040, a Clark 63 NIL with the r-m allele. Clark 63 is a NIL of Clark with the rxp and Rps1 alleles. A DNA fragment of 13 060 bp was inserted in the intron of Glyma.09G235100 in L72-2040. The fragment had the CACTA motif at both ends, imperfect terminal inverted repeats (TIR), inverse repetition of short sequence motifs close to the 5' and 3' ends, and a duplication of three nucleotides at the site of integration, indicating that it belongs to a CACTA-superfamily transposable element. We designated the element as Tgm11. Overall nucleotide sequence, motifs of TIR, and subterminal repeats were similar to those of Tgm1 and Tgs1, suggesting that these elements comprise a family.

NCX-DB: a unified resource for integrative analysis of the sodium calcium exchanger super-family.

Science.gov (United States)

Bode, Katrin; O'Halloran, Damien M

2018-04-13

Na + /Ca 2+ exchangers are low-affinity high-capacity transporters that mediate Ca 2+ extrusion by coupling Ca 2+ efflux to the influx of Na + ions. The Na + /Ca 2+ exchangers form a super-family comprised of three branches each differing in ion-substrate selectivity: Na + /Ca 2+ exchangers (NCX), Na + /Ca 2+ /K + exchangers, and Ca 2+ /cation exchangers. Their primary function is to maintain Ca 2+ homeostasis and play a particularly important role in excitable cells that experience transient Ca 2+ fluxes. Research into the role and activity of Na + /Ca 2+ exchangers has focused extensively on the cardio-vascular system, however, growing evidence suggests that Na + /Ca 2+ exchangers play a key role in neuronal processes such as memory formation, learning, oligodendrocyte differentiation, neuroprotection during brain ischemia and axon guidance. They have also been implicated in pathologies such as Alzheimer's disease, Parkinson's disease, Multiple Sclerosis and Epilepsy, however, a clear understanding of their mechanism during disease is lacking. To date, there has never been a central resource or database for Na + /Ca 2+ exchangers. With clear disease relevance and ever-increasing research on Na + /Ca 2+ exchangers from both model and non-model species, a database that unifies the data on Na + /Ca 2+ exchangers is needed for future research. NCX-DB is a publicly available database with a web interface that enables users to explore various Na + /Ca 2+ exchangers, perform cross-species sequence comparison, identify new exchangers, and stay-up to date with recent literature. NCX-DB is available on the web via an interactive user interface with an intuitive design, which is applicable for the identification and comparison of Na + /Ca 2+ exchanger proteins across diverse species.

Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy

International Nuclear Information System (INIS)

Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke; Hirobe, Sachiko; Nakagawa, Shinsaku; Okada, Naoki

2016-01-01

Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period of pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. - Highlights: • We established highly efficient gene transduction protocols for murine T cells. • CD8"+ CAR-T cells had antigen-specific cytotoxic activity. • CD4"+ CAR-T cells secreted multiple cytokines by antigen stimulation. • This finding can contribute to the development of T-cell biology and immunotherapy.

Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy

Energy Technology Data Exchange (ETDEWEB)

Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke; Hirobe, Sachiko; Nakagawa, Shinsaku, E-mail: nakagawa@phs.osaka-u.ac.jp; Okada, Naoki, E-mail: okada@phs.osaka-u.ac.jp

2016-04-22

Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period of pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. - Highlights: • We established highly efficient gene transduction protocols for murine T cells. • CD8{sup +} CAR-T cells had antigen-specific cytotoxic activity. • CD4{sup +} CAR-T cells secreted multiple cytokines by antigen stimulation. • This finding can contribute to the development of T-cell biology and immunotherapy.

Examining the relationship between psychological distress and adherence to anti-retroviral therapy among Ugandan adolescents living with HIV.

Science.gov (United States)

Mutumba, Massy; Musiime, Victor; Lepkwoski, James M; Harper, Gary W; Snow, Rachel C; Resnicow, Ken; Bauermeister, Jose A

2016-07-01

Psychological distress is common among adolescents living with HIV (ALHIV) worldwide, and has been associated with non-adherence to anti-retroviral therapy (ART), leading to poor virologic suppression, drug resistance, and increased risk for AIDS morbidity and mortality. However, only a few studies have explored the relationship between psychological distress and ART adherence among adolescents in sub-Saharan Africa. The paper examines the relationship between psychological distress and ART adherence, and effect of psychosocial resources on ART adherence. We conducted a cross-sectional survey of 464 ALHIV (aged 12-19; 53% female) seeking HIV care at a large HIV treatment center in Kampala, Uganda. ALHIV were recruited during routine clinic visits. Three self-reported binary adherence measures were utilized: missed pills in the past three days, non-adherence to the prescribed medical regimen, and self-rated adherence assessed using a visual analog scale. Psychological distress was measured as a continuous variable, and computed as the mean score on a locally developed and validated 25-item symptom checklist for Ugandan ALHIV. Psychosocial resources included spirituality, religiosity, optimism, social support, and coping strategies. After adjusting for respondents' socio-demographic characteristics and psychosocial resources, a unit increase in psychological distress was associated with increased odds of missing pills in past 3 days (Odds Ratio(OR) = 1.75; Confidence Interval (CI): 1.04-2.95), not following the prescribed regimen (OR = 1.63; CI: 1.08-2.46), and lower self-rated adherence (OR = 1.79; CI: 1.19-2.69). Psychosocial resources were associated with lower odds for non-adherence on all three self-report measures. There is a need to strengthen the psychosocial aspects of adolescent HIV care by developing interventions to identify and prevent psychological distress among Ugandan ALHIV.

The viral transmembrane superfamily: possible divergence of Arenavirus and Filovirus glycoproteins from a common RNA virus ancestor

Directory of Open Access Journals (Sweden)

Buchmeier Michael J

2001-02-01

Full Text Available Abstract Background Recent studies of viral entry proteins from influenza, measles, human immunodeficiency virus, type 1 (HIV-1, and Ebola virus have shown, first with molecular modeling, and then X-ray crystallographic or other biophysical studies, that these disparate viruses share a coiled-coil type of entry protein. Results Structural models of the transmembrane glycoproteins (GP-2 of the Arenaviruses, lymphochoriomeningitis virus (LCMV and Lassa fever virus, are presented, based on consistent structural propensities despite variation in the amino acid sequence. The principal features of the model, a hydrophobic amino terminus, and two antiparallel helices separated by a glycosylated, antigenic apex, are common to a number of otherwise disparate families of enveloped RNA viruses. Within the first amphipathic helix, demonstrable by circular dichroism of a peptide fragment, there is a highly conserved heptad repeat pattern proposed to mediate multimerization by coiled-coil interactions. The amino terminal 18 amino acids are 28% identical and 50% highly similar to the corresponding region of Ebola, a member of the Filovirus family. Within the second, charged helix just prior to membrane insertion there is also high similarity over the central 18 amino acids in corresponding regions of Lassa and Ebola, which may be further related to the similar region of HIV-1 defining a potent antiviral peptide analogue. Conclusions These findings indicate a common pattern of structure and function among viral transmembrane fusion proteins from a number of virus families. Such a pattern may define a viral transmembrane superfamily that evolved from a common precursor eons ago.

Motif III in superfamily 2 "helicases" helps convert the binding energy of ATP into a high-affinity RNA binding site in the yeast DEAD-box protein Ded1.

Science.gov (United States)

Banroques, Josette; Doère, Monique; Dreyfus, Marc; Linder, Patrick; Tanner, N Kyle

2010-03-05

Motif III in the putative helicases of superfamily 2 is highly conserved in both its sequence and its structural context. It typically consists of the sequence alcohol-alanine-alcohol (S/T-A-S/T). Historically, it was thought to link ATPase activity with a "helicase" strand displacement activity that disrupts RNA or DNA duplexes. DEAD-box proteins constitute the largest family of superfamily 2; they are RNA-dependent ATPases and ATP-dependent RNA binding proteins that, in some cases, are able to disrupt short RNA duplexes. We made mutations of motif III (S-A-T) in the yeast DEAD-box protein Ded1 and analyzed in vivo phenotypes and in vitro properties. Moreover, we made a tertiary model of Ded1 based on the solved structure of Vasa. We used Ded1 because it has relatively high ATPase and RNA binding activities; it is able to displace moderately stable duplexes at a large excess of substrate. We find that the alanine and the threonine in the second and third positions of motif III are more important than the serine, but that mutations of all three residues have strong phenotypes. We purified the wild-type and various mutants expressed in Escherichia coli. We found that motif III mutations affect the RNA-dependent hydrolysis of ATP (k(cat)), but not the affinity for ATP (K(m)). Moreover, mutations alter and reduce the affinity for single-stranded RNA and subsequently reduce the ability to disrupt duplexes. We obtained intragenic suppressors of the S-A-C mutant that compensate for the mutation by enhancing the affinity for ATP and RNA. We conclude that motif III and the binding energy of gamma-PO(4) of ATP are used to coordinate motifs I, II, and VI and the two RecA-like domains to create a high-affinity single-stranded RNA binding site. It also may help activate the beta,gamma-phosphoanhydride bond of ATP. (c) 2009 Elsevier Ltd. All rights reserved.

Modulation of chromatin structure by the FACT histone chaperone complex regulates HIV-1 integration.

Science.gov (United States)

Matysiak, Julien; Lesbats, Paul; Mauro, Eric; Lapaillerie, Delphine; Dupuy, Jean-William; Lopez, Angelica P; Benleulmi, Mohamed Salah; Calmels, Christina; Andreola, Marie-Line; Ruff, Marc; Llano, Manuel; Delelis, Olivier; Lavigne, Marc; Parissi, Vincent

2017-07-28

Insertion of retroviral genome DNA occurs in the chromatin of the host cell. This step is modulated by chromatin structure as nucleosomes compaction was shown to prevent HIV-1 integration and chromatin remodeling has been reported to affect integration efficiency. LEDGF/p75-mediated targeting of the integration complex toward RNA polymerase II (polII) transcribed regions ensures optimal access to dynamic regions that are suitable for integration. Consequently, we have investigated the involvement of polII-associated factors in the regulation of HIV-1 integration. Using a pull down approach coupled with mass spectrometry, we have selected the FACT (FAcilitates Chromatin Transcription) complex as a new potential cofactor of HIV-1 integration. FACT is a histone chaperone complex associated with the polII transcription machinery and recently shown to bind LEDGF/p75. We report here that a tripartite complex can be formed between HIV-1 integrase, LEDGF/p75 and FACT in vitro and in cells. Biochemical analyzes show that FACT-dependent nucleosome disassembly promotes HIV-1 integration into chromatinized templates, and generates highly favored nucleosomal structures in vitro. This effect was found to be amplified by LEDGF/p75. Promotion of this FACT-mediated chromatin remodeling in cells both increases chromatin accessibility and stimulates HIV-1 infectivity and integration. Altogether, our data indicate that FACT regulates HIV-1 integration by inducing local nucleosomes dissociation that modulates the functional association between the incoming intasome and the targeted nucleosome.

Role of a new member of IGFBP superfamily, IGFBP-rP10, in proliferation and differentiation of osteoblastic cells

International Nuclear Information System (INIS)

Shibata, Yasuaki; Tsukazaki, Tomoo; Hirata, Kazunari; Xin Cheng; Yamaguchi, Akira

2004-01-01

Bone regeneration is critically regulated by various molecules. To identify the new genes involved in bone regeneration, we performed microarray-based gene expression analysis using a mouse bone regeneration model. We identified a new member of the IGFBP superfamily, designated IGFBP-rP10, whose expression is up-regulated at the early phase of bone regeneration. IGFBP-rP10 consists of an IGFBP homologous domain followed by a Kazal-type protein inhibitor domain and an immunoglobulin G-like domain. A real-time-based RT-PCR analysis demonstrated that various tissues including bone expressed IGFBP-rP10 mRNA in various degrees, and confirmed an up-regulation at the early phase of bone regeneration. In situ hybridization revealed that osteoblastic cells expressed IGFPB-rP10 mRNA during bone regeneration. Bone morphogenetic protein-2 increased the expression level of IGFBP-rP10 mRNA in various cells including C3H10T1/2, MC3T3-E1, C2C12, and primary murine osteoblastic cells. The addition of recombinant mouse IGFBP-rP10 promoted the proliferation of these cells but failed to stimulate alkaline phosphatase activity. These results suggest that IGFBP-rP10 is involved in the proliferation of osteoblasts during bone formation and bone regeneration

Identification of an internal ribosome entry segment in the 5' region of the mouse VL30 retrotransposon and its use in the development of retroviral vectors.

Science.gov (United States)

López-Lastra, M; Ulrici, S; Gabus, C; Darlix, J L

1999-10-01

Mouse virus-like 30S RNAs (VL30m) constitute a family of retrotransposons, present at 100 to 200 copies, dispersed in the mouse genome. They display little sequence homology to Moloney murine leukemia virus (MoMLV), do not encode virus-like proteins, and have not been implicated in retroviral carcinogenesis. However, VL30 RNAs are efficiently packaged into MLV particles that are propagated in cell culture. In this study, we addressed whether the 5' region of VL30m could replace the 5' leader of MoMLV functionally in a recombinant vector construct. Our data confirm that the putative packaging sequence of VL30 is located within the 5' region (nucleotides 362 to 1149 with respect to the cap structure) and that it can replace the packaging sequence of MoMLV. We also show that VL30m contains an internal ribosome entry segment (IRES) in the 5' region, as do MoMLV, Friend murine leukemia virus, Harvey murine sarcoma virus, and avian reticuloendotheliosis virus type A. Our data show that both the packaging and IRES functions of the 5' region of VL30m RNA can be efficiently used to develop retrotransposon-based vectors.

Common gene variants in the tumor necrosis factor (TNF and TNF receptor superfamilies and NF-kB transcription factors and non-Hodgkin lymphoma risk.

Directory of Open Access Journals (Sweden)

Sophia S Wang

Full Text Available A promoter polymorphism in the pro-inflammatory cytokine tumor necrosis factor (TNF (TNF G-308A is associated with increased non-Hodgkin lymphoma (NHL risk. The protein product, TNF-alpha, activates the nuclear factor kappa beta (NF-kappaB transcription factor, and is critical for inflammatory and apoptotic responses in cancer progression. We hypothesized that the TNF and NF-kappaB pathways are important for NHL and that gene variations across the pathways may alter NHL risk.We genotyped 500 tag single nucleotide polymorphisms (SNPs from 48 candidate gene regions (defined as 20 kb 5', 10 kb 3' in the TNF and TNF receptor superfamilies and the NF-kappaB and related transcription factors, in 1946 NHL cases and 1808 controls pooled from three independent population-based case-control studies. We obtained a gene region-level summary of association by computing the minimum p-value ("minP test". We used logistic regression to compute odds ratios and 95% confidence intervals for NHL and four major NHL subtypes in relation to SNP genotypes and haplotypes. For NHL, the tail strength statistic supported an overall relationship between the TNF/NF-kappaB pathway and NHL (p = 0.02. We confirmed the association between TNF/LTA on chromosome 6p21.3 with NHL and found the LTA rs2844484 SNP most significantly and specifically associated with the major subtype, diffuse large B-cell lymphoma (DLBCL (p-trend = 0.001. We also implicated for the first time, variants in NFKBIL1 on chromosome 6p21.3, associated with NHL. Other gene regions identified as statistically significantly associated with NHL included FAS, IRF4, TNFSF13B, TANK, TNFSF7 and TNFRSF13C. Accordingly, the single most significant SNPs associated with NHL were FAS rs4934436 (p-trend = 0.0024, IRF4 rs12211228 (p-trend = 0.0026, TNFSF13B rs2582869 (p-trend = 0.0055, TANK rs1921310 (p-trend = 0.0025, TNFSF7 rs16994592 (p-trend = 0.0024, and TNFRSF13C rs6002551 (p-trend = 0.0074. All associations were

Mouse Mammary Tumor Virus Promoter-Containing Retroviral Promoter Conversion Vectors for Gene-Directed Enzyme Prodrug Therapy are Functional in Vitro and in Vivo

Directory of Open Access Journals (Sweden)

Reinhard Klein

2008-01-01

Full Text Available Gene directed-enzyme prodrug therapy (GDEPT is an approach for sensitization of tumor cells to an enzymatically activated, otherwise nontoxic, prodrug. Cytochrome P450 2B1 (CYP2B1 metabolizes the prodrugs cyclophosphamide (CPA and ifosfamide (IFA to produce the cytotoxic substances phosphoramide mustard and isophosphoramide mustard as well as the byproduct acrolein. We have constructed a retroviral promoter conversion (ProCon vector for breast cancer GDEPT. The vector allows expression of CYP2B1 from the mouse mammary tumor virus (MMTV promoter known to be active in the mammary glands of transgenic animals. It is anticipated to be used for the generation of encapsulated viral vector producing cells which, when placed inside or close to a tumor, will act as suppliers of the therapeutic CYP2B1 protein as well as of the therapeutic vector itself. The generated vector was effectively packaged by virus producing cells and allowed the production of high levels of enzymatically active CYP2B1 in infected cells which sensitized them to killing upon treatment with both IFA and CPA. Determination of the respective IC50 values demonstrated that the effective IFA dose was reduced by sixteen folds. Infection efficiencies in vivo were determined using a reporter gene-bearing vector in a mammary cancer cell-derived xenograft tumor mouse model.

Mouse RC/BTB2, a Member of the RCC1 Superfamily, Localizes to Spermatid Acrosomal Vesicles

Science.gov (United States)

Shen, Xuening; Nagarkatti-Gude, David R.; Hess, Rex A.; Henderson, Scott C.; Strauss, Jerome F.; Zhang, Zhibing

2012-01-01

Mouse RC/BTB2 is an unstudied protein of the RCC1 (Regulator of Chromosome Condensation) superfamily. Because of the significant remodeling of chromatin that occurs during spermiogenesis, we characterized the expression and localization of mouse RC/BTB2 in the testis and male germ cells. The Rc/btb2 gene yields two major transcripts: 2.3 kb Rc/btb2-s, present in most somatic tissues examined; and 2.5 kb Rc/btb2-t, which contains a unique non-translated exon in its 5′-UTR that is only detected in the testis. During the first wave of spermatogenesis, Rc/btb2-t mRNA is expressed from day 8 after birth, reaching highest levels of expression at day 30 after birth. The full-length protein contains three RCC1 domains in the N-terminus, and a BTB domain in the C-terminus. In the testis, the protein is detectable from day 12, but is progressively up-regulated to day 30 and day 42 after birth. In spermatids, some of the protein co-localizes with acrosomal markers sp56 and peanut lectin, indicating that it is an acrosomal protein. A GFP-tagged RCC1 domain is present throughout the cytoplasm of transfected CHO cells. However, both GFP-tagged, full-length RC/BTB2 and a GFP-tagged BTB domain localize to vesicles in close proximity to the nuclear membrane, suggesting that the BTB domain might play a role in mediating full-length RC/BTB2 localization. Since RCC1 domains associate with Ran, a small GTPase that regulates molecular trafficking, it is possible that RC/BTB2 plays a role in transporting proteins during acrosome formation. PMID:22768142

Adherence to anti-retroviral therapy & factors associated with it: A community based cross-sectional study from West Bengal, India

Directory of Open Access Journals (Sweden)

Sobha Pahari

2015-01-01

Full Text Available Background & objectives: Failure to adhere to anti-retroviral therapy (ART can lead to a range of unfavourable consequences impacting upon people living with HIV (PLH and society. It is, therefore, paramount that ART adherence is measured in a reliable manner and factors associated with adherence are identified. Lack of such data from West Bengal necessitated undertaking the current study. Methods: Participants were included during August-October, 2011 from three Drop-In-Centres (DICs from the three districts of West Bengal, India. ART-adherence was calculated by using formula based on pill-count and records collected from ART-card in possession of each of the 128 consenting adult PLH. Information on self-reported adherence, socio-demography, and adherence influencing issues was also collected through interviewer-administered questionnaire. Results: Of the 128 PLH, 99 (77% and 93 (73% PLH had ≥90 per cent and ≥95 per cent adherence, respectively to ART. Conversely, subjective reporting captured much higher proportion of PLH as ′well adherent′; a finding having implications for ongoing ART programme. Factors, independently associated with poor adherence (<90%, were ′7 th to 12 th month period of ART intake′ (adjusted OR=9.5; 90% CI 1.9 - 47.3; p0 =0.02 and ′non-disclosure of HIV status to family members′ (adjusted OR=4; 90% CI 1.3 - 13; P=0.05. Results at 95 per cent adherence cut-off were similar. Interpretation & conclusions: Enabling environment, which would encourage people to disclose their HIV status and in turn seek adherence partners from families and beyond and ongoing adherence-counselling appear to be important issues in the programme. Relevance of these study findings in wider context is conceivable.

The Foldback-like element Galileo belongs to the P superfamily of DNA transposons and is widespread within the Drosophila genus.

Science.gov (United States)

Marzo, Mar; Puig, Marta; Ruiz, Alfredo

2008-02-26

Galileo is the only transposable element (TE) known to have generated natural chromosomal inversions in the genus Drosophila. It was discovered in Drosophila buzzatii and classified as a Foldback-like element because of its long, internally repetitive, terminal inverted repeats (TIRs) and lack of coding capacity. Here, we characterized a seemingly complete copy of Galileo from the D. buzzatii genome. It is 5,406 bp long, possesses 1,229-bp TIRs, and encodes a 912-aa transposase similar to those of the Drosophila melanogaster 1360 (Hoppel) and P elements. We also searched the recently available genome sequences of 12 Drosophila species for elements similar to Dbuz\\Galileo by using bioinformatic tools. Galileo was found in six species (ananassae, willistoni, peudoobscura, persimilis, virilis, and mojavensis) from the two main lineages within the Drosophila genus. Our observations place Galileo within the P superfamily of cut-and-paste transposons and extend considerably its phylogenetic distribution. The interspecific distribution of Galileo indicates an ancient presence in the genus, but the phylogenetic tree built with the transposase amino acid sequences contrasts significantly with that of the species, indicating lineage sorting and/or horizontal transfer events. Our results also suggest that Foldback-like elements such as Galileo may evolve from DNA-based transposon ancestors by loss of the transposase gene and disproportionate elongation of TIRs.

Pessoas vivendo com HIV/AIDS: variáveis associadas à adesão ao tratamento anti-retroviral Persons living with HIV/AIDS: factors associated with adherence to antiretroviral treatment

Directory of Open Access Journals (Sweden)

Eliane Maria Fleury Seidl

2007-10-01

Full Text Available O estudo objetivou descrever o comportamento de adesão ao tratamento anti-retroviral em pessoas vivendo com HIV/AIDS e investigar preditores da adesão entre as variáveis escolaridade, presença de efeitos colaterais, interrupção anterior da terapia anti-retroviral (TARV por conta própria, auto-estima, expectativa de auto-eficácia, estratégias de enfrentamento, suporte social e satisfação com a relação profissional de saúde-usuário. Adesão foi medida pelo auto-relato da perda do número de comprimidos/cápsulas dos medicamentos anti-retrovirais na última semana e mês, sendo considerada satisfatória na ocorrência de omissão inferior a 5% do total prescrito. Participaram 101 pessoas, 60,4% homens, idades entre 20 a 71 anos (M = 37,9 anos, 73,3% sintomáticos. A coleta de dados incluiu entrevista e instrumentos auto-aplicáveis. A maioria (n = 73; 72,3% relatou adesão igual ou superior a 95%. Nos resultados da regressão logística, interrupção anterior da TARV e expectativa de auto-eficácia foram preditores significativos da adesão. Faz-se necessária a qualificação da assistência pela constituição de equipes interdisciplinares, para o desenvolvimento de abordagens adequadas às dificuldades médicas e psicossociais de adesão das pessoas vivendo com HIV/AIDS.This study aimed to describe the adherence of persons living with HIV/AIDS to antiretroviral therapy (ART and to investigate adherence predictors among the following: level of schooling, presence of side effects, current or previous interruption of ART by the persons themselves, self-esteem, self-efficacy expectation, coping strategies, social support, and satisfaction with the health professional-patient relationship. Adherence was measured by self-reported number of ART pills/capsules missed during the previous week and previous month, evaluated as satisfactory when less than 5%. 101 HIV+ adults took part in this study, 60.4% males, ranging from 20 to 71 years

[Efficacy of dolutegravir in treatment-experienced patients: the SAILING and VIKING trials].

Science.gov (United States)

Moreno, Santiago; Berenguer, Juan

2015-03-01

Dolutegravir is an HIV integrase inhibitor with a high genetic barrier to resistance and is active against raltegravir- and/or elvitegravir-resistant strains. The clinical development of dolutegravir for HIV infection rescue therapy is based on 3 clinical trials. In the SAILING trial, dolutegravir (5 mg once daily) in combination with 2 other antiretroviral agents was well tolerated and showed greater virological effect than raltegravir (400 mg twice daily) in the treatment of integrase inhibitor-naïve adults with virological failure infected with HIV strains with at least two-class drug resistance. The VIKING studies were designed to evaluate the efficacy of dolutegravir as rescue therapy in treatment-experienced patients infected with HIV strains with resistance mutations to raltegravir and/or elvitegravir. VIKING-1-2 was a dose-ranging phase IIb trial. VIKING-3 was a phase III trial in which dolutegravir (50 mg twice daily) formed part of an optimized regimen and proved safe and effective in this difficult-to-treat group of patients. Dolutegravir is the integrase inhibitor of choice for rescue therapy in multiresistant HIV infection, both in integrase inhibitor-naïve patients and in those previously treated with raltegravir or elvitegravir. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

International Nuclear Information System (INIS)

Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

2008-01-01

The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo

Structure-based virtual screening toward the discovery of novel inhibitors for impeding the protein-protein interaction between HIV-1 integrase and human lens epithelium-derived growth factor (LEDGF/p75).

Science.gov (United States)

Panwar, Umesh; Singh, Sanjeev Kumar

2017-10-23

HIV-1 integrase is a unique promising component of the viral replication cycle, catalyzing the integration of reverse transcribed viral cDNA into the host cell genome. Generally, IN activity requires both viral as well as a cellular co-factor in the processing replication cycle. Among them, the human lens epithelium-derived growth factor (LEDGF/p75) represented as promising cellular co-factor which supports the viral replication by tethering IN to the chromatin. Due to its major importance in the early steps of HIV replication, the interaction between IN and LEDGF/p75 has become a pleasing target for anti-HIV drug discovery. The present study involves the finding of novel inhibitor based on the information of dimeric CCD of IN in complex with known inhibitor, which were carried out by applying a structure-based virtual screening concept with molecular docking. Additionally, Free binding energy, ADME properties, PAINS analysis, Density Functional Theory, and Enrichment Calculations were performed on selected compounds for getting a best lead molecule. On the basis of these analyses, the current study proposes top 3 compounds: Enamine-Z742267384, Maybridge-HTS02400, and Specs-AE-848/37125099 with acceptable pharmacological properties and enhanced binding affinity to inhibit the interaction between IN and LEDGF/p75. Furthermore, Simulation studies were carried out on these molecules to expose their dynamics behavior and stability. We expect that the findings obtained here could be future therapeutic agents and may provide an outline for the experimental studies to stimulate the innovative strategy for research community.

Evolutionary history and functional divergence of the cytochrome P450 gene superfamily between Arabidopsis thaliana and Brassica species uncover effects of whole genome and tandem duplications.

Science.gov (United States)

Yu, Jingyin; Tehrim, Sadia; Wang, Linhai; Dossa, Komivi; Zhang, Xiurong; Ke, Tao; Liao, Boshou

2017-09-18

The cytochrome P450 monooxygenase (P450) superfamily is involved in the biosynthesis of various primary and secondary metabolites. However, little is known about the effects of whole genome duplication (WGD) and tandem duplication (TD) events on the evolutionary history and functional divergence of P450s in Brassica after splitting from a common ancestor with Arabidopsis thaliana. Using Hidden Markov Model search and manual curation, we detected that Brassica species have nearly 1.4-fold as many P450 members as A. thaliana. Most P450s in A. thaliana and Brassica species were located on pseudo-chromosomes. The inferred phylogeny indicated that all P450s were clustered into two different subgroups. Analysis of WGD event revealed that different P450 gene families had appeared after evolutionary events of species. For the TD event analyses, the P450s from TD events in Brassica species can be divided into ancient and recent parts. Our comparison of influence of WGD and TD events on the P450 gene superfamily between A. thaliana and Brassica species indicated that the family-specific evolution in the Brassica lineage can be attributed to both WGD and TD, whereas WGD was recognized as the major mechanism for the recent evolution of the P450 super gene family. Expression analysis of P450s from A. thaliana and Brassica species indicated that WGD-type P450s showed the same expression pattern but completely different expression with TD-type P450s across different tissues in Brassica species. Selection force analysis suggested that P450 orthologous gene pairs between A. thaliana and Brassica species underwent negative selection, but no significant differences were found between P450 orthologous gene pairs in A. thaliana-B. rapa and A. thaliana-B. oleracea lineages, as well as in different subgenomes in B. rapa or B. oleracea compared with A. thaliana. This study is the first to investigate the effects of WGD and TD on the evolutionary history and functional divergence of P450