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Sample records for envelope protein vp51a

  1. A 3D model of the membrane protein complex formed by the white spot syndrome virus structural proteins.

    Directory of Open Access Journals (Sweden)

    Yun-Shiang Chang

    Full Text Available BACKGROUND: Outbreaks of white spot disease have had a large negative economic impact on cultured shrimp worldwide. However, the pathogenesis of the causative virus, WSSV (whit spot syndrome virus, is not yet well understood. WSSV is a large enveloped virus. The WSSV virion has three structural layers surrounding its core DNA: an outer envelope, a tegument and a nucleocapsid. In this study, we investigated the protein-protein interactions of the major WSSV structural proteins, including several envelope and tegument proteins that are known to be involved in the infection process. PRINCIPAL FINDINGS: In the present report, we used coimmunoprecipitation and yeast two-hybrid assays to elucidate and/or confirm all the interactions that occur among the WSSV structural (envelope and tegument proteins VP51A, VP19, VP24, VP26 and VP28. We found that VP51A interacted directly not only with VP26 but also with VP19 and VP24. VP51A, VP19 and VP24 were also shown to have an affinity for self-interaction. Chemical cross-linking assays showed that these three self-interacting proteins could occur as dimers. CONCLUSIONS: From our present results in conjunction with other previously established interactions we construct a 3D model in which VP24 acts as a core protein that directly associates with VP26, VP28, VP38A, VP51A and WSV010 to form a membrane-associated protein complex. VP19 and VP37 are attached to this complex via association with VP51A and VP28, respectively. Through the VP26-VP51C interaction this envelope complex is anchored to the nucleocapsid, which is made of layers of rings formed by VP664. A 3D model of the nucleocapsid and the surrounding outer membrane is presented.

  2. Functional Analysis of Glycosylation of Zika Virus Envelope Protein

    OpenAIRE

    Camila R. Fontes-Garfias; Chao Shan; Huanle Luo; Muruato, Antonio E.; Medeiros, Daniele B.A.; Elizabeth Mays; Xuping Xie; Jing Zou; Roundy, Christopher M; Maki Wakamiya; Rossi, Shannan L.; Tian Wang; Weaver, Scott C.; Pei-Yong Shi

    2017-01-01

    Summary: Zika virus (ZIKV) infection causes devastating congenital abnormities and Guillain-Barré syndrome. The ZIKV envelope (E) protein is responsible for viral entry and represents a major determinant for viral pathogenesis. Like other flaviviruses, the ZIKV E protein is glycosylated at amino acid N154. To study the function of E glycosylation, we generated a recombinant N154Q ZIKV that lacks the E glycosylation and analyzed the mutant virus in mammalian and mosquito hosts. In mouse models...

  3. Top-down protein identification using isotopic envelope fingerprinting.

    Science.gov (United States)

    Xiao, Kaijie; Yu, Fan; Tian, Zhixin

    2017-01-30

    For top-down protein database search and identification from tandem mass spectra, our isotopic envelope fingerprinting search algorithm and ProteinGoggle search engine have demonstrated their strength of efficiently resolving heavily overlapping data as well separating non-ideal data with non-ideal isotopic envelopes from ideal ones with ideal isotopic envelopes. Here we report our updated ProteinGoggle 2.0 for intact protein database search with full-capacity. The indispensable updates include users' optional definition of dynamic post-translational modifications and static chemical labeling during database creation, comprehensive dissociation methods and ion series, as well as a Proteoform Score for each proteoform. ProteinGoggle has previously been benchmarked with both collision-based dissociation (CID, HCD) and electron-based dissociation (ETD) data of either intact proteins or intact proteomes. Here we report our further benchmarking of the new version of ProteinGoggle with publically available photon-based dissociation (UVPD) data (http://hdl.handle.net/2022/17316) of intact E. coli ribosomal proteins. Protein species (aka proteoforms) function at their molecular level, and diverse structures and biological roles of every proteoform come from often co-occurring proteolysis, amino acid variation and post-translational modifications. Complete and high-throughput capture of this combinatorial information of proteoforms has become possible in evolving top-down proteomics; yet, various methods and technologies, especially database search and bioinformatics identification tools, in the top-down pipeline are still in their infancy stages and demand intensive research and development. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Inactivation of enveloped virus by laser-driven protein aggregation

    Science.gov (United States)

    Tsen, Shaw-Wei D.; Chapa, Travis; Beatty, Wandy; Tsen, Kong-Thon; Yu, Dong; Achilefu, Samuel

    2012-12-01

    Ultrafast lasers in the visible and near-infrared range have emerged as a potential new method for pathogen reduction of blood products and pharmaceuticals. However, the mechanism of enveloped virus inactivation by this method is unknown. We report the inactivation as well as the molecular and structural effects caused by visible (425 nm) femtosecond laser irradiation on murine cytomegalovirus (MCMV), an enveloped, double-stranded DNA virus. Our results show that laser irradiation (1) caused a 5-log reduction in MCMV titer, (2) did not cause significant changes to the global structure of MCMV virions including membrane and capsid, as assessed by electron microscopy, (3) produced no evidence of double-strand breaks or crosslinking in MCMV genomic DNA, and (4) caused selective aggregation of viral capsid and tegument proteins. We propose a model in which ultrafast laser irradiation induces partial unfolding of viral proteins by disrupting hydrogen bonds and/or hydrophobic interactions, leading to aggregation of closely associated viral proteins and inactivation of the virus. These results provide new insight into the inactivation of enveloped viruses by visible femtosecond lasers at the molecular level, and help pave the way for the development of a new ultrafast laser technology for pathogen reduction.

  5. Overexpression of Ebola virus envelope GP1 protein.

    Science.gov (United States)

    Zou, Zhongcheng; Misasi, John; Sullivan, Nancy; Sun, Peter D

    2017-07-01

    Ebola virus uses its envelope GP1 and GP2 for viral attachment and entry into host cells. Due to technical difficulty expressing full-length envelope, many structural and functional studies of Ebola envelope protein have been carried out primarily using GP1 lacking its mucin-like domain. As a result, the viral invasion mechanisms involving the mucin-like domain are not fully understood. To elucidate the role of the mucin-like domain of GP1 in Ebola-host attachment and infection and to facilitate vaccine development, we constructed a GP1 expression vector containing the entire attachment region (1-496). Cysteine 53 of GP1, which forms a disulfide bond with GP2, was mutated to serine to avoid potential disulfide bond mispairing. Stable expression clones using codon optimized open reading frame were developed in human 293-H cells with yields reaching ∼25 mg of GP1 protein per liter of spent medium. Purified GP1 was functional and bound to Ebola attachment receptors, DC-SIGN and DC-SIGNR. The over-expression and easy purification characteristic of this system has implications in Ebola research and vaccine development. To further understand the differential expression yields between the codon optimized and native GP1, we analyzed the presence of RNA structural motifs in the first 100 nucleotides of translational initiation AUG site. RNA structural prediction showed the codon optimization removed two potential RNA pseudoknot structures. This methodology is also applicable to the expression of other difficult virus envelope proteins. Published by Elsevier Inc.

  6. Functional Analysis of Glycosylation of Zika Virus Envelope Protein

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    Camila R. Fontes-Garfias

    2017-10-01

    Full Text Available Summary: Zika virus (ZIKV infection causes devastating congenital abnormities and Guillain-Barré syndrome. The ZIKV envelope (E protein is responsible for viral entry and represents a major determinant for viral pathogenesis. Like other flaviviruses, the ZIKV E protein is glycosylated at amino acid N154. To study the function of E glycosylation, we generated a recombinant N154Q ZIKV that lacks the E glycosylation and analyzed the mutant virus in mammalian and mosquito hosts. In mouse models, the mutant was attenuated, as evidenced by lower viremia, decreased weight loss, and no mortality; however, knockout of E glycosylation did not significantly affect neurovirulence. Mice immunized with the mutant virus developed a robust neutralizing antibody response and were completely protected from wild-type ZIKV challenge. In mosquitoes, the mutant virus exhibited diminished oral infectivity for the Aedes aegypti vector. Collectively, the results demonstrate that E glycosylation is critical for ZIKV infection of mammalian and mosquito hosts. : Zika virus (ZIKV causes devastating congenital abnormities and Guillain-Barré syndrome. Fontes-Garfias et al. showed that the glycosylation of ZIKV envelope protein plays an important role in infecting mosquito vectors and pathogenesis in mouse. Keywords: Zika virus, glycosylation, flavivirus entry, mosquito transmission, vaccine

  7. Crystal Structure of the Japanese Encephalitis Virus Envelope Protein

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    Luca, Vincent C.; AbiMansour, Jad; Nelson, Christopher A.; Fremont, Daved H. (WU-MED)

    2012-03-13

    Japanese encephalitis virus (JEV) is the leading global cause of viral encephalitis. The JEV envelope protein (E) facilitates cellular attachment and membrane fusion and is the primary target of neutralizing antibodies. We have determined the 2.1-{angstrom} resolution crystal structure of the JEV E ectodomain refolded from bacterial inclusion bodies. The E protein possesses the three domains characteristic of flavivirus envelopes and epitope mapping of neutralizing antibodies onto the structure reveals determinants that correspond to the domain I lateral ridge, fusion loop, domain III lateral ridge, and domain I-II hinge. While monomeric in solution, JEV E assembles as an antiparallel dimer in the crystal lattice organized in a highly similar fashion as seen in cryo-electron microscopy models of mature flavivirus virions. The dimer interface, however, is remarkably small and lacks many of the domain II contacts observed in other flavivirus E homodimers. In addition, uniquely conserved histidines within the JEV serocomplex suggest that pH-mediated structural transitions may be aided by lateral interactions outside the dimer interface in the icosahedral virion. Our results suggest that variation in dimer structure and stability may significantly influence the assembly, receptor interaction, and uncoating of virions.

  8. Coronavirus envelope (E) protein remains at the site of assembly

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    Venkatagopalan, Pavithra [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Daskalova, Sasha M. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); Department of Biochemistry and Chemistry, Arizona State University, Tempe, AZ 85287-5401 (United States); Lopez, Lisa A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Molecular and Cellular Biology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Dolezal, Kelly A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Hogue, Brenda G., E-mail: Brenda.Hogue@asu.edu [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States)

    2015-04-15

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes.

  9. The Zika virus envelope protein glycan loop regulates virion antigenicity.

    Science.gov (United States)

    Goo, Leslie; DeMaso, Christina R; Pelc, Rebecca S; Ledgerwood, Julie E; Graham, Barney S; Kuhn, Richard J; Pierson, Theodore C

    2018-01-02

    Because antibodies are an important component of flavivirus immunity, understanding the antigenic structure of flaviviruses is critical. Compared to dengue virus (DENV), the loop containing the single N-linked glycosylation site on Zika virus (ZIKV) envelope (E) proteins extends further towards the DII fusion loop (DII-FL) on neighboring E proteins within E dimers on mature viruses. Although ZIKV is poorly neutralized by DII-FL antibodies, we demonstrated significantly increased neutralization sensitivity of ZIKV particles incorporating the DENV glycan loop. Increased neutralization sensitivity was independent of E protein glycosylation: ZIKV lacking E protein glycans remained poorly neutralized, whereas ZIKV loop chimeras with or without an E protein glycan were potently neutralized. ZIKV particles lacking the E protein glycan were capable of infecting Raji cells expressing the lectin DC-SIGNR, suggesting the prM glycan of partially mature particles can facilitate entry. Our study provides insight into the determinants of ZIKV E protein function and antigenicity. Copyright © 2017. Published by Elsevier Inc.

  10. Implication of Human Endogenous Retrovirus Envelope Proteins in Placental Functions

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    Adjimon Gatien Lokossou

    2014-11-01

    Full Text Available Human endogenous retroviruses (ERVs represent 8% of the total human genome. Although the majority of these ancient proviral sequences have only retained non-coding long terminal repeats (LTRs, a number of “endogenized” retroviral genes encode functional proteins. Previous studies have underlined the implication of these ERV-derived proteins in the development and the function of the placenta. In this review, we summarize recent findings showing that two ERV genes, termed Syncytin-1 and Syncytin-2, which encode former envelope (Env proteins, trigger fusion events between villous cytotrophoblasts and the peripheral multinucleated syncytiotrophoblast layer. Such fusion events maintain the stability of this latter cell structure, which plays an important role in fetal development by the active secretion of various soluble factors, gas exchange and regulation of fetomaternal immunotolerance. We also highlight new studies showing that these ERV proteins, in addition to their localization at the cell surface of cytotrophoblasts, are also incorporated on the surface of various extracellular microvesicles, including exosomes. Such exosome-associated proteins could be involved in the various functions attributed to these vesicles and could provide a form of tropism. Additionally, through their immunosuppressive domains, these ERV proteins could also contribute to fetomaternal immunotolerance in a local and more distal manner. These various aspects of the implication of Syncytin-1 and -2 in placental function are also addressed in the context of the placenta-related disorder, preeclampsia.

  11. Coronavirus envelope (E) protein remains at the site of assembly.

    Science.gov (United States)

    Venkatagopalan, Pavithra; Daskalova, Sasha M; Lopez, Lisa A; Dolezal, Kelly A; Hogue, Brenda G

    2015-04-01

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Particle-based delivery of the HIV envelope protein.

    Science.gov (United States)

    Asbach, Benedikt; Wagner, Ralf

    2017-05-01

    A major focus in HIV vaccine research is the development of suitable antigens that elicit broadly neutralizing antibody responses targeting HIV's envelope protein (Env). Delivery of Env in a repetitive manner on particle-based carriers allows higher avidity interactions and is therefore expected to efficiently engage B cells, thus leading to affinity maturation that results in superior antibody responses characterized by improved breadth, potency, and durability. This review summarizes current work that is evaluating diverse types of such particulate carriers for Env delivery. Various types of particle scaffolds are being investigated, encompassing group-specific antigen-derived virus-like particles, bacteria-derived proteins that self-assemble into symmetrical nanoparticles, as well as liposomes assembled from membrane components and recombinantly produced Env isoforms. Env-derived antigens from peptides over selected isolates to improved, stabilized next-generation designer Envs have been attached to such carriers. Immunological evaluation in animal models showed that these structures often elicit superior humoral immune responses. The findings reviewed here emphasize the potential of particle-based delivery modalities to elicit better antibody responses. Together with advances in Env antigen design, these approaches may synergistically act together on the way to obtain vaccine candidates that potentially induce protective immune responses against HIV.

  13. Functional Analysis of Glycosylation of Zika Virus Envelope Protein.

    Science.gov (United States)

    Fontes-Garfias, Camila R; Shan, Chao; Luo, Huanle; Muruato, Antonio E; Medeiros, Daniele B A; Mays, Elizabeth; Xie, Xuping; Zou, Jing; Roundy, Christopher M; Wakamiya, Maki; Rossi, Shannan L; Wang, Tian; Weaver, Scott C; Shi, Pei-Yong

    2017-10-31

    Zika virus (ZIKV) infection causes devastating congenital abnormities and Guillain-Barré syndrome. The ZIKV envelope (E) protein is responsible for viral entry and represents a major determinant for viral pathogenesis. Like other flaviviruses, the ZIKV E protein is glycosylated at amino acid N154. To study the function of E glycosylation, we generated a recombinant N154Q ZIKV that lacks the E glycosylation and analyzed the mutant virus in mammalian and mosquito hosts. In mouse models, the mutant was attenuated, as evidenced by lower viremia, decreased weight loss, and no mortality; however, knockout of E glycosylation did not significantly affect neurovirulence. Mice immunized with the mutant virus developed a robust neutralizing antibody response and were completely protected from wild-type ZIKV challenge. In mosquitoes, the mutant virus exhibited diminished oral infectivity for the Aedes aegypti vector. Collectively, the results demonstrate that E glycosylation is critical for ZIKV infection of mammalian and mosquito hosts. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Interaction of Zika Virus Envelope Protein with Glycosaminoglycans.

    Science.gov (United States)

    Kim, So Young; Zhao, Jing; Liu, Xinyue; Fraser, Keith; Lin, Lei; Zhang, Xing; Zhang, Fuming; Dordick, Jonathan S; Linhardt, Robert J

    2017-02-28

    In February 2016, the World Health Organization declared a Public Health Emergency of International Concern on Zika Virus (ZIKV), because of its association with severe fetal anomalies of congenitally infected humans. This has led to urgent efforts by academic, federal, and industry research groups to improve our understanding of the pathogenesis of ZIKV and to develop detection methods, therapeutic strategies, and vaccines. Although we still do not have the entire picture of the pathogenesis of ZIKV, extensive research has been conducted on related pathogenic flaviviruses (i.e., dengue virus, West Nile virus, and yellow fever virus). Binding to glycosaminoglycans (GAGs) through its envelope protein is the first step in successful host cell invasion of dengue virus. In this study, we examined ZIKV envelope protein (ZIKV E) binding to GAGs in a real time interaction study using surface plasmon resonance (SPR) to explore the role of GAGs in host cell entry of ZIKV into placenta and brain. ZIKV E strongly binds (KD = 443 nM) pharmaceutical heparin (HP), a highly sulfated GAG, and binds with lower avidity to less sulfated GAGs, suggesting that the ZIKV E-GAG interaction may be electrostatically driven. Using SPR competition assays with various chain length HP oligosaccharides (from 4 to 18 saccharide units in length), we observed that ZIKV E preferentially binds to longer HP oligosaccharides (with 8-18 saccharides). Next, we examined GAGs prepared from human placentas to determine if they bound ZIKV E, possibly mediating placental cell invasion of ZIKV. Compositional analysis of these GAGs as well as SPR binding studies showed that both chondroitin sulfate and heparan sulfate GAGs, present on the placenta, showed low-micromolar interactions with ZIKV E. Both porcine brain CS and HS also showed micromolar binding with ZIKV E. Moreover, heparan sulfate with a higher TriS content, the dominant repeating unit of HP, shows a high affinity for ZIKV E. These results suggest

  15. Expression of hepatitis B virus large envelope protein in Escherichia coli and Saccharomyces cerevisiae.

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    Korec, E; Korcová, J; Palková, Z; Vondrejs, V; Korínek, V; Reinis, M; Bichko, V V; Hlozánek, I

    1989-01-01

    The gene coding for hepatitis B large envelope protein was cloned under the lac promoter in bacterial vector pUC-8 and under the ADH1 promoter in yeast expression shuttle vector pVT103-U, and expression of HBsAg in bacteria and yeast was determined. The strongest expression of large envelope protein was obtained after transformation of the protease-deficient yeast strain BJ1991. The recombinant large envelope protein did not form complex 22-nm particles and was not secreted into medium.

  16. Analysis of VSV pseudotype virus infection mediated by rubella virus envelope proteins

    National Research Council Canada - National Science Library

    Masafumi Sakata; Hideki Tani; Masaki Anraku; Michiyo Kataoka; Noriyo Nagata; Fumio Seki; Maino Tahara; Noriyuki Otsuki; Kiyoko Okamoto; Makoto Takeda; Yoshio Mori

    2017-01-01

    .... To establish an infection the host cells must be susceptible and permissible. To assess the susceptibility of individual cell lines, we generated a pseudotype vesicular stomatitis virus bearing RV envelope proteins (VSV-RV/CE2E1...

  17. Envelope protein requirements for the assembly of infectious virions of porcine reproductive and respiratory syndrome virus

    NARCIS (Netherlands)

    Wissink, E.H.J.; Kroese, M.V.; Wijk, van H.A.; Rijsewijk, F.A.M.; Meulenberg, J.J.; Rottier, P.J.M.

    2005-01-01

    Virions of porcine reproductive and respiratory syndrome virus (PRRSV) contain six membrane proteins: the major proteins GP5 and M and the minor proteins GP2a, E, GP3, and GP4. Here, we studied the envelope protein requirements for PRRSV particle formation and infectivity using full-length cDNA

  18. that Bind Specifically to Recombinant Envelope Protein of Dengue

    African Journals Online (AJOL)

    Keywords: Dengue virus envelope, Biotinylation, Ni-NTA purification, Target epitopes, Plaque assay,. Competitive blocking assay. Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus,. International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, ...

  19. HIV-1 envelope trimer fusion proteins and their applications

    NARCIS (Netherlands)

    Sliepen, K.H.E.W.J.

    2016-01-01

    HIV-1 is a major threat to global health and a vaccine is not yet on the horizon. A successful HIV-1 vaccine should probably induce HIV-1 neutralizing antibodies that target the envelope glycoprotein (Env) trimer on the outside of the virion. A possible starting point for such a vaccine are soluble

  20. Exploring the evolution of the proteins of the plant nuclear envelope.

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    Poulet, Axel; Probst, Aline V; Graumann, Katja; Tatout, Christophe; Evans, David

    2017-01-02

    In this study, we explore the plasticity during evolution of proteins of the higher plant nuclear envelope (NE) from the most ancestral plant species to advanced angiosperms. The higher plant NE contains a functional Linker of Nucleoskeleton and Cytoskeleton (LINC) complex based on conserved Sad1-Unc84 (SUN) domain proteins and plant specific Klarsicht/Anc1/Syne homology (KASH) domain proteins. Recent evidence suggests the presence of a plant lamina underneath the inner membrane and various coiled-coil proteins have been hypothesized to be associated with it including Crowded Nuclei (CRWN; also termed LINC and NMCP), Nuclear Envelope Associated Protein (NEAP) protein families as well as the CRWN binding protein KAKU4. SUN domain proteins appear throughout with a key role for mid-SUN proteins suggested. Evolution of KASH domain proteins has resulted in increasing complexity, with some appearing in all species considered, while other KASH proteins are progressively gained during evolution. Failure to identify CRWN homologs in unicellular organisms included in the study and their presence in plants leads us to speculate that convergent evolution may have occurred in the formation of the lamina with each kingdom having new proteins such as the Lamin B receptor (LBR) and Lamin-Emerin-Man1 (LEM) domain proteins (animals) or NEAPs and KAKU4 (plants). Our data support a model in which increasing complexity at the nuclear envelope occurred through the plant lineage and suggest a key role for mid-SUN proteins as an early and essential component of the nuclear envelope.

  1. Deltabaculoviruses encode a functional type I budded virus envelope fusion protein

    Science.gov (United States)

    Envelope fusion proteins (F proteins) are major constituents of budded viruses (BVs) of alpha- and betabaculoviruses (Baculoviridae) and are essential for the systemic infection of insect larvae and insect cells in culture. An F protein homolog gene was absent in gammabaculoviruses. Here we show tha...

  2. Shrimp arginine kinase being a binding protein of WSSV envelope protein VP31

    Science.gov (United States)

    Ma, Cuiyan; Gao, Qiang; Liang, Yan; Li, Chen; Liu, Chao; Huang, Jie

    2016-11-01

    Viral entry into the host is the earliest stage of infection in the viral life cycle in which attachment proteins play a key role. VP31 (WSV340/WSSV396), an envelope protein of white spot syndrome virus (WSSV), contains an Arg-Gly-Asp (RGD) peptide domain known as a cellular attachment site. At present, the process of VP31 interacting with shrimp host cells has not been explored. Therefore, the VP31 gene was cloned into pET30a (+), expressed in Escherichia coli strain BL21 and purified with immobilized metal ion affinity chromatography. Four gill cellular proteins of shrimp ( Fenneropenaeus chinensis) were pulled down by an affinity column coupled with recombinant VP31 (rVP31), and the amino acid sequences were identified with MALDI-TOF/TOF mass spectrometry. Hemocyanin, beta-actin, arginine kinase (AK), and an unknown protein were suggested as the putative VP31 receptor proteins. SDS-PAGE showed that AK is the predominant binding protein of VP31. An i n vitro binding activity experiment indicated that recombinant AK's (rAK) binding activity with rVP31 is comparable to that with the same amount of WSSV. These results suggested that AK, as a member of the phosphagen kinase family, plays a role in WSSV infection. This is the first evidence showing that AK is a binding protein of VP31. Further studies on this topic will elucidate WSSV infection mechanism in the future.

  3. Enveloped virus inactivation using neutral arginine solutions and applications in therapeutic protein purification processes.

    Science.gov (United States)

    McCue, Justin T; Selvitelli, Keith; Cecchini, Doug; Brown, Rhonda

    2014-01-01

    For the manufacturing of recombinant protein therapeutics produced from mammalian cell culture, demonstrating the capacity of the purification process to effectively clear infectious viruses is a regulatory requirement. At least two process steps, using different mechanisms of virus removal and/or inactivation, should be validated in support of the regulatory approval process. For example, exposure of the product stream to low pH, detergents or solvent/detergent combinations is commonly incorporated in protein purification processes for the inactivation of lipid-enveloped viruses. However, some proteins have limited stability at low pH or in the presence of the detergents, and alternative techniques for achieving the inactivation of enveloped viruses would be beneficial. We present here an alternative and novel approach for the rapid inactivation of enveloped viruses using pH-neutral buffer solutions containing arginine. The implementation of this approach in a monoclonal antibody or Fc-fusion protein purification process is described and illustrated with several different therapeutic proteins. The use of the neutral pH arginine solution was able to effectively inactivate two enveloped model viruses, with no measurable effect on the product quality of the investigated proteins. Thus, the use of pH-neutral arginine containing buffer solutions provides an alternative means of virus inactivation where other forms of virus inactivation, such as low pH and/or solvent/detergent treatments are not possible or undesirable due to protein stability limitations. © 2013 American Institute of Chemical Engineers.

  4. Assembly of SIV virus-like particles containing envelope proteins using a baculovirus expression system.

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    Yamshchikov, G V; Ritter, G D; Vey, M; Compans, R W

    1995-12-01

    The requirements for SIV particle assembly and envelope incorporation were investigated using a baculovirus expression system. The Pr56gag precursor protein expressed under control of the polyhedrin promoter (pPolh) produced high levels of immature retrovirus-like particles (VLP) upon expression in Sf9 insect cells. To determine the optimal conditions for envelope protein (Env) incorporation into VLP, two recombinant baculoviruses expressing the SIV envelope protein under control of a very late pPolh or a hybrid late/very late capsid/polyhedrin (Pcap/polh) promoter and a recombinant expressing a truncated form of the SIV envelope protein (Envt) under the hybrid Pcap/polh promoter were compared. We have observed that utilization of the earlier hybrid promoter resulted in higher levels of Env expression on the cell surface and its incorporation into budding virus particles. We have also found that the Envt protein is transported to the cell surface of insect cells and incorporated into VLP more efficiently than full-length Env. In addition, we examined the effect of coexpression of the protease furin, which has been implicated in the proteolytic cleavage of the Env precursor gp160 in mammalian cells. Coexpression of furin in insect cells resulted in more efficient proteolytic cleavage into gp120 and gp41, and the cleaved proteins were incorporated into VLP.

  5. The overexpression of nuclear envelope protein Lap2β induces endoplasmic reticulum reorganisation via membrane stacking

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    Ekaterina G. Volkova

    2012-06-01

    Some nuclear envelope proteins are localised to both the nuclear envelope and the endoplasmic reticulum; therefore, it seems plausible that even small amounts of these proteins can influence the organisation of the endoplasmic reticulum. A simple method to study the possible effects of nuclear envelope proteins on endoplasmic reticulum organisation is to analyze nuclear envelope protein overexpression. Here, we demonstrate that Lap2β overexpression can induce the formation of cytoplasmic vesicular structures derived from endoplasmic reticulum membranes. Correlative light and electron microscopy demonstrated that these vesicular structures were composed of a series of closely apposed membranes that were frequently arranged in a circular fashion. Although stacked endoplasmic reticulum cisternae were highly ordered, Lap2β could readily diffuse into and out of these structures into the surrounding reticulum. It appears that low-affinity interactions between cytoplasmic domains of Lap2β can reorganise reticular endoplasmic reticulum into stacked cisternae. Although the effect of one protein may be insignificant at low concentrations, the cumulative effect of many non-specialised proteins may be significant.

  6. Distinct pathways mediate the sorting of tail-anchored proteins to the plastid outer envelope.

    Directory of Open Access Journals (Sweden)

    Preetinder K Dhanoa

    Full Text Available BACKGROUND: Tail-anchored (TA proteins are a distinct class of membrane proteins that are sorted post-translationally to various organelles and function in a number of important cellular processes, including redox reactions, vesicular trafficking and protein translocation. While the molecular targeting signals and pathways responsible for sorting TA proteins to their correct intracellular destinations in yeasts and mammals have begun to be characterized, relatively little is known about TA protein biogenesis in plant cells, especially for those sorted to the plastid outer envelope. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the biogenesis of three plastid TA proteins, including the 33-kDa and 34-kDa GTPases of the translocon at the outer envelope of chloroplasts (Toc33 and Toc34 and a novel 9-kDa protein of unknown function that we define here as an outer envelope TA protein (OEP9. Using a combination of in vivo and in vitro assays we show that OEP9 utilizes a different sorting pathway than that used by Toc33 and Toc34. For instance, while all three TA proteins interact with the cytosolic OEP chaperone/receptor, AKR2A, the plastid targeting information within OEP9 is distinct from that within Toc33 and Toc34. Toc33 and Toc34 also appear to differ from OEP9 in that their insertion is dependent on themselves and the unique lipid composition of the plastid outer envelope. By contrast, the insertion of OEP9 into the plastid outer envelope occurs in a proteinaceous-dependent, but Toc33/34-independent manner and membrane lipids appear to serve primarily to facilitate normal thermodynamic integration of this TA protein. CONCLUSIONS/SIGNIFICANCE: Collectively, the results provide evidence in support of at least two sorting pathways for plastid TA outer envelope proteins and shed light on not only the complex diversity of pathways involved in the targeting and insertion of proteins into plastids, but also the molecular mechanisms that underlie

  7. Expression and regulation of cornified envelope proteins in human corneal epithelium.

    Science.gov (United States)

    Tong, Louis; Corrales, Rosa M; Chen, Zhuo; Villarreal, Arturo L; De Paiva, Cintia S; Beuerman, Roger; Li, De-Quan; Pflugfelder, Stephen C

    2006-05-01

    Stratified squamous epithelial cells assemble a specialized protective barrier structure on their periphery, termed the cornified envelope. The purpose of this study was to evaluate the presence and distribution of cornified envelope precursors in human corneal epithelium, their expression in human corneal epithelial cell cultures, and the effect of ultraviolet radiation (UVB) and transglutaminase (TG) inhibition on their expression. Tissue distribution of small proline-rich proteins (SPRRs) and filaggrin and involucrin was studied in human cornea sections by immunofluorescence staining. Primary human corneal epithelial cells (HCECs) from limbal explants were used in cell culture experiments. A single dose of UVB at 20 mJ/cm2 was used to stimulate these cells, in the presence or absence of mono-dansyl cadaverine (MDC), a TG inhibitor. SPRR2 and involucrin protein levels were studied by immunofluorescence staining and Western blot analysis. Gene expression of 12 proteins was investigated by semiquantitative reverse transcription-polymerase chain reaction. In human cornea tissue, SPRR1, SPRR2, filaggrin, and involucrin protein expression were detected in the central and peripheral corneal and limbal epithelium. In HCECs, SPRR2 and involucrin proteins were detected in the cytosolic fraction, and involucrin levels increased after UVB. Both SPRR2 and involucrin levels accumulated in the presence of MDC. Nine genes including involucrin, SPRR (types 1A, 1B, 2A, 2B, and 3), late envelope protein (LEP) 1 and 16, and filaggrin were expressed by HCECs. SPRR 4, loricrin, and LEP 6 transcripts were not detected. UVB downregulated SPRR (2A, 2B) and LEP 1 transcripts. Various envelope precursors are expressed in human corneal epithelium and in HCECs, acute UVB stress differentially alters their expression in HCECs. The expression of envelope precursors and their rapid modulation by UVB supports the role of these proteins in the regulation of ocular surface stress. TG function may

  8. Envelope protein complexes of Mycobacterium avium subsp. paratuberculosis and their antigenicity

    Science.gov (United States)

    Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s disease, a chronic enteric disease of ruminant animals. In the present study, blue native PAGE electrophoresis and 2D SDS-PAGE were used to separate MAP envelope protein complexes, followed by mass spectrometry (MS) ...

  9. Potential molecular mimicry between the human endogenous retrovirus W family envelope proteins and myelin proteins in multiple sclerosis.

    Science.gov (United States)

    Ramasamy, Ranjan; Joseph, Blessy; Whittall, Trevor

    2017-03-01

    Multiple sclerosis is an autoimmune disease caused by the destruction of the myelin sheath in the central nervous system. The major target molecules for the immune response are the myelin basic protein, myelin oligodendrocyte glycoprotein and proteolipid protein but the aetiology of the disease is as yet poorly understood. The HLA Class II allele DRB1*1501 in particular as well as DRB5*0101 and the expression of human endogenous retroviral envelope proteins have been linked to multiple sclerosis but the molecular mechanisms relating these remain to be elucidated. We hypothesised that cross-reactive peptide epitopes in retroviral envelope proteins and myelin proteins that can be presented by the two Class II DR molecules may play a role in initiating multiple sclerosis. Sequence homologies between retroviral envelope and myelin proteins and in silico predictions of peptides derived from them that are able to bind to the two Class II alleles were examined to test the hypothesis. The results support the hypothesis that molecular mimicry in peptide epitopes from envelope proteins of the HERV-W family of endogenous retroviruses and myelin proteins is possible and could potentially trigger multiple sclerosis. Mimicry between syncytin-1, a HERV-W envelope protein that is expressed during placentation, and myelin proteins may also explain the higher prevalence of multiple sclerosis in women. Experiments to test the ability of the identified peptide epitopes to activate T H cells are required to confirm the present findings. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  10. Comparison of Egg Envelope Thickness in Teleosts and its Relationship to the Sites of ZP Protein Synthesis.

    Science.gov (United States)

    Sano, Kaori; Kawaguchi, Mari; Katano, Keita; Tomita, Kenji; Inokuchi, Mayu; Nagasawa, Tatsuki; Hiroi, Junya; Kaneko, Toyoji; Kitagawa, Takashi; Fujimoto, Takafumi; Arai, Katsutoshi; Tanaka, Masaru; Yasumasu, Shigeki

    2017-05-01

    Teleost egg envelope generally consists of a thin outer layer and a thick inner layer. The inner layer of the Pacific herring egg envelope is further divided into distinct inner layers I and II. In our previous study, we cloned four zona pellucida (ZP) proteins (HgZPBa, HgZPBb, HgZPCa, and HgZPCb) from Pacific herring, two of which (HgZPBa and HgZPCa) were synthesized in the liver and two (HgZPBb and HgZPCb) in the ovary. In this study, we raised antibodies against these four proteins to identify their locations using immunohistochemistry. Our results suggest that inner layer I is constructed primarily of HgZPBa and Ca, whereas inner layer II consists primarily of HgZPBa. HgZPBb and Cb were minor components of the envelope. Therefore, the egg envelope of Pacific herring is primarily composed of liver-synthesized ZP proteins. A comparison of the thickness of the fertilized egg envelopes of 55 species suggested that egg envelopes derived from liver-synthesized ZP proteins tended to be thicker in demersal eggs than those in pelagic eggs, whereas egg envelopes derived from ovarian-synthesized ZP proteins had no such tendency. Our comparison suggests that the prehatching period of an egg with a thick egg envelope is longer than that of an egg with a thin egg envelope. We hypothesized that acquisition of liver-synthesized ZP proteins during evolution conferred the ability to develop a thick egg envelope, which allowed species with demersal eggs to adapt to mechanical stress in the prehatching environment by thickening the egg envelope, while pelagic egg envelopes have remained thin. © 2017 Wiley Periodicals, Inc.

  11. Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Zhang, Huaidong [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Gong, Rui, E-mail: gongr@wh.iov.cn [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China)

    2015-05-08

    Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish.

  12. Membrane vesiculation induced by proteins of the dengue virus envelope studied by molecular dynamics simulations

    Science.gov (United States)

    de Oliveira dos Santos Soares, Ricardo; Oliveira Bortot, Leandro; van der Spoel, David; Caliri, Antonio

    2017-12-01

    Biological membranes are continuously remodeled in the cell by specific membrane-shaping machineries to form, for example, tubes and vesicles. We examine fundamental mechanisms involved in the vesiculation processes induced by a cluster of envelope (E) and membrane (M) proteins of the dengue virus (DENV) using molecular dynamics simulations and a coarse-grained model. We show that an arrangement of three E-M heterotetramers (EM3) works as a bending unit and an ordered cluster of five such units generates a closed vesicle, reminiscent of the virus budding process. In silico mutagenesis of two charged residues of the anchor helices of the envelope proteins of DENV shows that Arg-471 and Arg-60 are fundamental to produce bending stress on the membrane. The fine-tuning between the size of the EM3 unit and its specific bending action suggests this protein unit is an important factor in determining the viral particle size.

  13. Reduction of a 4q35-encoded nuclear envelope protein in muscle differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, Cecilia [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Guan, Tinglu [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Figlewicz, Denise A. [Department of Neurology, University of Michigan, Ann Arbor, MI 48109 (United States); Hays, Arthur P. [Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Worman, Howard J. [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Gerace, Larry [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Schirmer, Eric C., E-mail: e.schirmer@ed.ac.uk [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR (United Kingdom)

    2009-11-13

    Muscular dystrophy and peripheral neuropathy have been linked to mutations in genes encoding nuclear envelope proteins; however, the molecular mechanisms underlying these disorders remain unresolved. Nuclear envelope protein p19A is a protein of unknown function encoded by a gene at chromosome 4q35. p19A levels are significantly reduced in human muscle as cells differentiate from myoblasts to myotubes; however, its levels are not similarly reduced in all differentiation systems tested. Because 4q35 has been linked to facioscapulohumeral muscular dystrophy (FSHD) and some adjacent genes are reportedly misregulated in the disorder, levels of p19A were analyzed in muscle samples from patients with FSHD. Although p19A was increased in most cases, an absolute correlation was not observed. Nonetheless, p19A downregulation in normal muscle differentiation suggests that in the cases where its gene is inappropriately re-activated it could affect muscle differentiation and contribute to disease pathology.

  14. Analysis of Pseudomonas aeruginosa cell envelope proteome by capture of surface-exposed proteins on activated magnetic nanoparticles.

    Directory of Open Access Journals (Sweden)

    Davide Vecchietti

    Full Text Available We report on specific magneto-capturing followed by Multidimensional Protein Identification Technology (MudPIT for the analysis of surface-exposed proteins of intact cells of the bacterial opportunistic pathogen Pseudomonas aeruginosa. The magneto-separation of cell envelope fragments from the soluble cytoplasmic fraction allowed the MudPIT identification of the captured and neighboring proteins. Remarkably, we identified 63 proteins captured directly by nanoparticles and 67 proteins embedded in the cell envelope fragments. For a high number of proteins, our analysis strongly indicates either surface exposure or localization in an envelope district. The localization of most identified proteins was only predicted or totally unknown. This novel approach greatly improves the sensitivity and specificity of the previous methods, such as surface shaving with proteases that was also tested on P. aeruginosa. The magneto-capture procedure is simple, safe, and rapid, and appears to be well-suited for envelope studies in highly pathogenic bacteria.

  15. Immunising with the transmembrane envelope proteins of different retroviruses including HIV-1

    Science.gov (United States)

    Denner, Joachim

    2013-01-01

    The induction of neutralizing antibodies is a promising way to prevent retrovirus infections. Neutralizing antibodies are mainly directed against the envelope proteins, which consist of two molecules, the surface envelope (SU) protein and the transmembrane envelope (TM) protein. Antibodies broadly neutralizing the human immunodeficiencvy virus-1 (HIV-1) and binding to the TM protein gp41 of the virus have been isolated from infected individuals. Their epitopes are located in the membrane proximal external region (MPER). Since there are difficulties to induce such neutralizing antibodies as basis for an effective AIDS vaccine, we performed a comparative analysis immunising with the TM proteins of different viruses from the family Retroviridae. Both subfamilies, the Orthoretrovirinae and the Spumaretrovirinae were included. In this study, the TM proteins of three gammaretroviruses including (1) the porcine endogenous retrovirus (PERV), (2) the Koala retrovirus (KoRV), (3) the feline leukemia virus (FeLV), of two lentiviruses, HIV-1, HIV-2, and of two spumaviruses, the feline foamy virus (FFV) and the primate foamy virus (PFV) were used for immunisation. Whereas in all immunisation studies binding antibodies were induced, neutralizing antibodies were only found in the case of the gammaretroviruses. The induced antibodies were directed against the MPER and the fusion peptide proximal region (FPPR) of their TM proteins; however only the antibodies against the MPER were neutralizing. Most importantly, the epitopes in the MPER were localized in the same position as the epitopes of the antibodies broadly neutralizing HIV-1 in the TM protein gp41 of HIV-1, indicating that the MPER is an effective target for the neutralization of retroviruses. PMID:23249763

  16. Bioprocessing and immobilization of cell envelope proteinases from Lactobacillus delbrueckii subsp. lactis 313, for protein degradation

    OpenAIRE

    Agyei, Dominic

    2017-01-01

    Proteolytic enzymes are a useful class of biomolecules due to their ubiquity and the plethora of physiological roles they play in living systems. These enzymes are esponsible for the breakdown of proteins to peptides and have several applications in food, pharmaceuticals, diagnostics, photographic, waste treatments, bioremediation, and in the textile industry. Cell-envelope proteinases (CEPs) are a special class of industrially relevant extracellular proteolytic enzymes obtained from la...

  17. Analysis of VSV pseudotype virus infection mediated by rubella virus envelope proteins.

    Science.gov (United States)

    Sakata, Masafumi; Tani, Hideki; Anraku, Masaki; Kataoka, Michiyo; Nagata, Noriyo; Seki, Fumio; Tahara, Maino; Otsuki, Noriyuki; Okamoto, Kiyoko; Takeda, Makoto; Mori, Yoshio

    2017-09-14

    Rubella virus (RV) generally causes a systemic infection in humans. Viral cell tropism is a key determinant of viral pathogenesis, but the tropism of RV is currently poorly understood. We analyzed various human cell lines and determined that RV only establishes an infection efficiently in particular non-immune cell lines. To establish an infection the host cells must be susceptible and permissible. To assess the susceptibility of individual cell lines, we generated a pseudotype vesicular stomatitis virus bearing RV envelope proteins (VSV-RV/CE2E1). VSV-RV/CE2E1 entered cells in an RV envelope protein-dependent manner, and thus the infection was neutralized completely by an RV-specific antibody. The infection was Ca2+-dependent and inhibited by endosomal acidification inhibitors, further confirming the dependency on RV envelope proteins for the VSV-RV/CE2E1 infection. Human non-immune cell lines were mostly susceptible to VSV-RV/CE2E1, while immune cell lines were much less susceptible than non-immune cell lines. However, susceptibility of immune cells to VSV-RV/CE2E1 was increased upon stimulation of these cells. Our data therefore suggest that immune cells are generally less susceptible to RV infection than non-immune cells, but the susceptibility of immune cells is enhanced upon stimulation.

  18. Cholesterol depletion of hepatoma cells impairs hepatitis B virus envelopment by altering the topology of the large envelope protein.

    NARCIS (Netherlands)

    Dorobantu, C.M.; Macovei, A.; Lazar, C.; Dwek, R.A.; Zitzmann, N.; Branza-Nichita, N.

    2011-01-01

    Previous reports have shown that cholesterol depletion of the membrane envelope of the hepatitis B virus (HBV) impairs viral infection of target cells. A potential function of this lipid in later steps of the viral life cycle remained controversial, with secretion of virions and subviral particles

  19. Homology Modeling and Conformational Epitope Prediction of Envelope Protein of Alkhumra Haemorrhagic Fever Virus

    Directory of Open Access Journals (Sweden)

    Naghmeh Poorinmohammad

    2015-10-01

    Full Text Available Background: The aim of this study was to generate in silico 3D-structure of the envelope protein of AHFV using homology modeling method to further predict its conformational epitopes and help other studies to investigate itsstructural features using the model.Methods: A 3D-structure prediction was developed for the envelope protein of Alkhumra haemorrhagic fever virus (AHFV, an emerging tick-borne flavivirus, based on a homology modeling method using M4T and Modwebservers, as the 3D-structure of the protein is not available yet. Modeled proteins were validated using Modfold 4 server and their accuracies were calculated based on their RSMDs. Having the 3D predicted model with high quality, conformational epitopes were predicted using DiscoTope 2.0.Results: Model generated by M4T was more acceptable than the Modweb-generated model. The global score and Pvalue calculated by Modfold 4 ensured that a certifiable model was generated by M4T, since its global score was almost near 1 which is the score for a high resolution X-ray crystallography structure. Furthermore, itsthe P-value was much lower than 0.001 which means that the model is completely acceptable. Having 0.46 Å rmsd, this model was shown to be highly accurate. Results from DiscoTope 2.0 showed 26 residues as epitopes, forming conformational epitopes of the modeled protein.Conclusion: The predicted model and epitopes for envelope protein of AHFV can be used in several therapeutic and diagnostic approaches including peptide vaccine development, structure based drug design or diagnostic kit development in order to facilitate the time consuming experimental epitope mapping process.

  20. Structural rearrangements in the membrane penetration protein of a non-enveloped virus

    Science.gov (United States)

    Dormitzer, Philip R.; Nason, Emma B.; Venkataram Prasad, B. V.; Harrison, Stephen C.

    2007-01-01

    Non-enveloped virus particles (those that lack a lipid-bilayer membrane) must breach the membrane of a target host cell to gain access to its cytoplasm. So far, the molecular mechanism of this membrane penetration step has resisted structural analysis. The spike protein VP4 is a principal component in the entry apparatus of rotavirus, a non-enveloped virus that causes gastro-enteritis and kills 440,000 children each year1. Trypsin cleavage of VP4 primes the virus for entry by triggering a rearrangement that rigidifies the VP4 spikes2. We have determined the crystal structure, at 3.2 Å resolution, of the main part of VP4 that projects from the virion. The crystal structure reveals a coiled-coil stabilized trimer. Comparison of this structure with the two-fold clustered VP4 spikes in a ~12 Å resolution image reconstruction from electron cryomicroscopy of trypsin-primed virions shows that VP4 also undergoes a second rearrangement, in which the oligomer reorganizes and each subunit folds back on itself, translocating a potential membrane-interaction peptide from one end of the spike to the other. This rearrangement resembles the conformational transitions of membrane fusion proteins of enveloped viruses3–6. PMID:15329727

  1. Western Blot Detection of Human Anti-Chikungunya Virus Antibody with Recombinant Envelope 2 Protein.

    Science.gov (United States)

    Yang, Zhaoshou; Lee, Jihoo; Ahn, Hye-Jin; Chong, Chom-Kyu; Dias, Ronaldo F; Nam, Ho-Woo

    2016-04-01

    Chikungunya virus (CHIKV), a tropical pathogen, has re-emerged and has massive outbreaks abruptly all over the world. Containing many dominant epitopes, the envelope E2 protein of CHIKV has been explored for the vaccination or diagnosis. In the present study, the antigenicity of a recombinant expressed intrinsically disorder domain (IUD) of E2 was tested for the detection of the antibody against CHIKV through western blot method. The gene of the IUD of E2 was inserted into 2 different vectors and expressed as recombinant GST-E2 and recombinant MBP-E2 fusion protein, respectively. Two kinds of fusion proteins were tested with 30 CHIKV patient sera and 30 normal sera, respectively. Both proteins were detected by 25 patients sera (83.3%) and 1 normal serum (3.3%). This test showed a relatively high sensitivity and very high specificity of the recombinant E2 proteins to be used as diagnostic antigens against CHIKV infection.

  2. Repairing oxidized proteins in the bacterial envelope using respiratory chain electrons.

    Science.gov (United States)

    Gennaris, Alexandra; Ezraty, Benjamin; Henry, Camille; Agrebi, Rym; Vergnes, Alexandra; Oheix, Emmanuel; Bos, Julia; Leverrier, Pauline; Espinosa, Leon; Szewczyk, Joanna; Vertommen, Didier; Iranzo, Olga; Collet, Jean-François; Barras, Frédéric

    2015-12-17

    The reactive species of oxygen and chlorine damage cellular components, potentially leading to cell death. In proteins, the sulfur-containing amino acid methionine is converted to methionine sulfoxide, which can cause a loss of biological activity. To rescue proteins with methionine sulfoxide residues, living cells express methionine sulfoxide reductases (Msrs) in most subcellular compartments, including the cytosol, mitochondria and chloroplasts. Here we report the identification of an enzymatic system, MsrPQ, repairing proteins containing methionine sulfoxide in the bacterial cell envelope, a compartment particularly exposed to the reactive species of oxygen and chlorine generated by the host defence mechanisms. MsrP, a molybdo-enzyme, and MsrQ, a haem-binding membrane protein, are widely conserved throughout Gram-negative bacteria, including major human pathogens. MsrPQ synthesis is induced by hypochlorous acid, a powerful antimicrobial released by neutrophils. Consistently, MsrPQ is essential for the maintenance of envelope integrity under bleach stress, rescuing a wide series of structurally unrelated periplasmic proteins from methionine oxidation, including the primary periplasmic chaperone SurA. For this activity, MsrPQ uses electrons from the respiratory chain, which represents a novel mechanism to import reducing equivalents into the bacterial cell envelope. A remarkable feature of MsrPQ is its capacity to reduce both rectus (R-) and sinister (S-) diastereoisomers of methionine sulfoxide, making this oxidoreductase complex functionally different from previously identified Msrs. The discovery that a large class of bacteria contain a single, non-stereospecific enzymatic complex fully protecting methionine residues from oxidation should prompt a search for similar systems in eukaryotic subcellular oxidizing compartments, including the endoplasmic reticulum.

  3. Nuclear Envelope Protein SUN2 Promotes Cyclophilin-A-Dependent Steps of HIV Replication

    Science.gov (United States)

    Lahaye, Xavier; Satoh, Takeshi; Gentili, Matteo; Cerboni, Silvia; Silvin, Aymeric; Conrad, Cécile; Ahmed-Belkacem, Abdelhakim; Rodriguez, Elisa C.; Guichou, Jean-François; Bosquet, Nathalie; Piel, Matthieu; Le Grand, Roger; King, Megan C.; Pawlotsky, Jean-Michel; Manel, Nicolas

    2016-01-01

    Summary During the early phase of replication, HIV reverse transcribes its RNA and crosses the nuclear envelope while escaping host antiviral defenses. The host factor Cyclophilin A (CypA) is essential for these steps and binds the HIV capsid; however, the mechanism underlying this effect remains elusive. Here, we identify related capsid mutants in HIV-1, HIV-2, and SIVmac that are restricted by CypA. This antiviral restriction of mutated viruses is conserved across species and prevents nuclear import of the viral cDNA. Importantly, the inner nuclear envelope protein SUN2 is required for the antiviral activity of CypA. We show that wild-type HIV exploits SUN2 in primary CD4+ T cells as an essential host factor that is required for the positive effects of CypA on reverse transcription and infection. Altogether, these results establish essential CypA-dependent functions of SUN2 in HIV infection at the nuclear envelope. PMID:27149839

  4. Nuclear Envelope Protein SUN2 Promotes Cyclophilin-A-Dependent Steps of HIV Replication

    Directory of Open Access Journals (Sweden)

    Xavier Lahaye

    2016-04-01

    Full Text Available During the early phase of replication, HIV reverse transcribes its RNA and crosses the nuclear envelope while escaping host antiviral defenses. The host factor Cyclophilin A (CypA is essential for these steps and binds the HIV capsid; however, the mechanism underlying this effect remains elusive. Here, we identify related capsid mutants in HIV-1, HIV-2, and SIVmac that are restricted by CypA. This antiviral restriction of mutated viruses is conserved across species and prevents nuclear import of the viral cDNA. Importantly, the inner nuclear envelope protein SUN2 is required for the antiviral activity of CypA. We show that wild-type HIV exploits SUN2 in primary CD4+ T cells as an essential host factor that is required for the positive effects of CypA on reverse transcription and infection. Altogether, these results establish essential CypA-dependent functions of SUN2 in HIV infection at the nuclear envelope.

  5. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins

    Energy Technology Data Exchange (ETDEWEB)

    Maric, Martina; Haugo, Alison C. [Department of Microbiology, University of Iowa, Iowa City, IA 52242 (United States); Dauer, William [Department of Neurology, University of Michigan, Ann Arbor, MI 48109 (United States); Johnson, David [Department of Microbiology and Immunology, Oregon Health Sciences University, Portland, OR 97201 (United States); Roller, Richard J., E-mail: richard-roller@uiowa.edu [Department of Microbiology, University of Iowa, Iowa City, IA 52242 (United States)

    2014-07-15

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. - Highlights: • We show that wild-type HSV can induce breakdown of the nuclear envelope in a specific cell system. • The viral fusion proteins gB and gH are required for induction of nuclear envelope breakdown. • Nuclear envelope breakdown cannot compensate for deletion of the HSV UL34 gene.

  6. Identification of unique SUN-interacting nuclear envelope proteins with diverse functions in plants.

    Science.gov (United States)

    Zhou, Xiao; Graumann, Katja; Wirthmueller, Lennart; Jones, Jonathan D G; Meier, Iris

    2014-06-09

    Although a plethora of nuclear envelope (NE) transmembrane proteins (NETs) have been identified in opisthokonts, plant NETs are largely unknown. The only known NET homologues in plants are Sad1/UNC-84 (SUN) proteins, which bind Klarsicht/ANC-1/Syne-1 homology (KASH) proteins. Therefore, de novo identification of plant NETs is necessary. Based on similarities between opisthokont KASH proteins and the only known plant KASH proteins, WPP domain-interacting proteins, we used a computational method to identify the KASH subset of plant NETs. Ten potential plant KASH protein families were identified, and five candidates from four of these families were verified for their NE localization, depending on SUN domain interaction. Of those, Arabidopsis thaliana SINE1 is involved in actin-dependent nuclear positioning in guard cells, whereas its paralogue SINE2 contributes to innate immunity against an oomycete pathogen. This study dramatically expands our knowledge of plant KASH proteins and suggests that plants and opisthokonts have recruited different KASH proteins to perform NE regulatory functions. © 2014 Zhou et al.

  7. Proteomic profiling of the surface-exposed cell envelope proteins of Caulobacter crescentus.

    Science.gov (United States)

    Cao, Yuan; Bazemore-Walker, Carthene R

    2014-01-31

    Biotinylation of intact cells, avidin enrichment of derivatized peptides, and shotgun proteomics were employed to reveal the composition of the surface-exposed proteome of the aquatic bacterium, Caulobacter crescentus. Ninety-one unique proteins were identified with the majority originating from the outer membrane, periplasm, and inner membrane, subcellular regions that comprise the Gram-negative bacterium cell envelope. Many of these proteins were described as 'conserved hypothetical protein' or 'hypothetical protein'; and so, the actual expression of these gene products was confirmed. Others did not have any known function or lacked annotation. However, this investigation of the Caulobacter surfaceome did reveal the unanticipated presence of a number of enzymes involved in protein degradation. The results presented here can provide a starting point for hypothesis-driven research projects focused on this bacterium in particular and centered on understanding Gram-negative cell architecture and outer membrane biogenesis broadly. The detected protein degradation enzymes anchored on or located within the outer membrane suggest that Caulobacter has nutrient sources larger than small molecules and/or further processes surface proteins once secreted to this location. Additionally, confirmation of outer membrane residency of those proteins predicted to be periplasmic or whose location prediction was not definitive could potentially elucidate the identities of Gram-negative specific anchorless surface proteins. This article is part of a Special Issue entitled: Trends in Microbial Proteomics. © 2013.

  8. Phylogenetic analysis of the envelope protein (domain lll of dengue 4 viruses

    Directory of Open Access Journals (Sweden)

    Mota Javier

    2002-01-01

    Full Text Available Objective. To evaluate the genetic variability of domain III of envelope (E protein and to estimate phylogenetic relationships of dengue 4 (Den-4 viruses isolated in Mexico and from other endemic areas of the world. Material and Methods. A phylogenetic study of domain III of envelope (E protein of Den-4 viruses was conducted in 1998 using virus strains from Mexico and other parts of the world, isolated in different years. Specific primers were used to amplify by RT-PCR the domain III and to obtain nucleotide sequence. Based on nucleotide and deduced aminoacid sequence, genetic variability was estimated and a phylogenetic tree was generated. To make an easy genetic analysis of domain III region, a Restriction Fragment Length Polymorphism (RFLP assay was performed, using six restriction enzymes. Results. Study results demonstrate that nucleotide and aminoacid sequence analysis of domain III are similar to those reported from the complete E protein gene. Based on the RFLP analysis of domain III using the restriction enzymes Nla III, Dde I and Cfo I, Den-4 viruses included in this study were clustered into genotypes 1 and 2 previously reported. Conclusions. Study results suggest that domain III may be used as a genetic marker for phylogenetic and molecular epidemiology studies of dengue viruses.

  9. Recent advances in understanding plant nuclear envelope proteins involved in nuclear morphology.

    Science.gov (United States)

    Tamura, Kentaro; Goto, Chieko; Hara-Nishimura, Ikuko

    2015-03-01

    The nuclear envelope (NE) is a fundamental structure of the nucleus and plays an important role in nuclear morphology through the strict regulation of NE protein function. Beyond its physical barrier function between nucleoplasm and cytoplasm, recent studies of the plant NE have provided novel insights into basic aspects of nuclear morphology as well as cellular organization. In this review, we focus on plant NE proteins that have emerged from recent studies in nuclear morphology, and we discuss their physiological functions in cellular activities. A better understanding of the NE protein functions should provide key insights into the physiological significance of proper nuclear structure in plants. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Function of nuclear membrane proteins in shaping the nuclear envelope integrity during closed mitosis.

    Science.gov (United States)

    Yang, Hui-Ju; Iwamoto, Masaaki; Hiraoka, Yasushi; Haraguchi, Tokuko

    2017-06-01

    The nuclear envelope (NE) not only protects the genome from being directly accessed by detrimental agents but also regulates genome organization. Breaches in NE integrity threaten genome stability and impede cellular function. Nonetheless, the NE constantly remodels, and NE integrity is endangered in dividing or differentiating cells. Specifically, in unicellular eukaryotes undergoing closed mitosis, the NE expands instead of breaking down during chromosome segregation. The newly assembling nuclear pore complexes (NPCs) penetrate the existing NE in interphase. A peculiar example of NE remodelling during nuclear differentiation in Tetrahymena involves formation of the redundant NE and clustered NPCs. Even under these conditions, the NE remains intact. Many recent studies on unicellular organisms have revealed that nuclear membrane proteins, such as LEM-domain proteins, play a role in maintaining NE integrity. This review summarizes and discusses how nuclear membrane proteins participate in NE integrity. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  11. Nuclear envelope proteins and chromatin arrangement: a pathogenic mechanism for laminopathies

    Directory of Open Access Journals (Sweden)

    NM Maraldi

    2009-06-01

    Full Text Available The involvement of the nuclear envelope in the modulation of chromatin organization is strongly suggested by the increasing number of human diseases due to mutations of nuclear envelope proteins. A common feature of these diseases, named laminopathies, is the occurrence of major chromatin defects. Laminopathies share in some instances their clinical features, but each of them is characterized by a phenotype that involves one or multiple tissues.We previously reported that cells from laminopathic patients show an altered nuclear profile, and loss or detachment of heterochromatin from the nuclear envelope. Recent evidence indicates that processing of the lamin A precursor is altered in laminopathies featuring pre-mature aging and/or lipodystrophy phenotype. In these cases, pre-lamin A is accumulated in the nucleus and heterochromatin is severely disorganized. Moreover, altered distribution and solubility properties of heterochromatin-associated proteins such as HP1 are observed. These findings indicate that defects of chromatin remodeling are involved in the cascade of epigenetic events leading to the laminopathic phenotypes. Here we report evidence indicating that pre-lamin A is mis-localized in the nuclei of Emery-Dreifuss muscular dystrophy fibroblasts, either bearing lamin A/C or emerin mutations. Abnornal pre-lamin A-containing structures are formed following treatment with a farnesyl-transferase inhibitor, a drug that causes accumulation of non-farnesylated pre-lamin A. Pre-lamin A-labeled structures co-localize with heterochromatin clumps. These data indicate that in almost all laminopathies the expression of the mutant lamin A precursor disrupts the organization of heterochromatin domains so that affected cells are unable to maintain the silenced chromatin state capable to allow/preserve terminal differentiation. Our results further show that the absence of emerin expression alters the distribution of pre-lamin A and of heterochromatin

  12. Vaccinia virus protein F12 associates with intracellular enveloped virions through an interaction with A36.

    Science.gov (United States)

    Johnston, Sara C; Ward, Brian M

    2009-02-01

    Vaccinia virus is the prototypical member of the family Poxviridae. Three morphologically distinct forms are produced during infection: intracellular mature virions (IMV), intracellular enveloped virions (IEV), and extracellular enveloped virions (EEV). Two viral proteins, F12 and A36, are found exclusively on IEV but not on IMV and EEV. Analysis of membranes from infected cells showed that F12 was only associated with membranes and is not an integral membrane protein. A yeast two-hybrid assay revealed an interaction between amino acids 351 to 458 of F12 and amino acids 91 to 111 of A36. We generated a recombinant vaccinia virus that expresses an F12, which lacks residues 351 to 458. Characterization of this recombinant revealed a small-plaque phenotype and a subsequent defect in virus release similar to a recombinant virus that had F12L deleted. In addition, F12 lacking residues 351 to 458 was unable to associate with membranes in infected cells. These results suggest that F12 associates with IEV through an interaction with A36 and that this interaction is critical for the function of F12 during viral egress.

  13. Stability of Retroviral Vectors Against Ultracentrifugation Is Determined by the Viral Internal Core and Envelope Proteins Used for Pseudotyping.

    Science.gov (United States)

    Kim, Soo-Hyun; Lim, Kwang-Il

    2017-05-31

    Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

  14. The Flavivirus Precursor Membrane-Envelope Protein Complex: Structure and Maturation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Long; Lok, Shee-Mei; Yu, I-Mei; Zhang, Ying; Kuhn, Richard J.; Chen, Jue; Rossmann, Michael G. (Purdue)

    2008-09-17

    Many viruses go through a maturation step in the final stages of assembly before being transmitted to another host. The maturation process of flaviviruses is directed by the proteolytic cleavage of the precursor membrane protein (prM), turning inert virus into infectious particles. We have determined the 2.2 angstrom resolution crystal structure of a recombinant protein in which the dengue virus prM is linked to the envelope glycoprotein E. The structure represents the prM-E heterodimer and fits well into the cryo-electron microscopy density of immature virus at neutral pH. The pr peptide {beta}-barrel structure covers the fusion loop in E, preventing fusion with host cell membranes. The structure provides a basis for identifying the stages of its pH-directed conformational metamorphosis during maturation, ending with release of pr when budding from the host.

  15. West Nile virus envelope proteins: nucleotide sequence analysis of strains differing in mouse neuroinvasiveness.

    Science.gov (United States)

    Chambers, T J; Halevy, M; Nestorowicz, A; Rice, C M; Lustig, S

    1998-10-01

    Several neuroinvasive and non-neuroinvasive West Nile (WN) viruses were characterized by nucleotide sequencing of their envelope (E) protein regions. Prolonged passage in mosquito cells caused loss of neuroinvasiveness and acquisition of an N-linked glycosylation site, which is utilized. Limited passage in cell culture also caused glycosylation but not attenuation, suggesting that glycosylation may not be directly responsible for attenuation and that a second mutation (L68 --> P) may also be involved. A monoclonal antibody-neutralization escape mutant with a substitution at residue 307, a site common to other flavivirus escape mutants, was also attenuated. A partially neuroinvasive revertant regained the parental E sequence, implying that determinants outside of the E region may also influence attenuation. Data suggest that the neuroinvasive determinants may be similar to those for other flaviviruses. Also, sequence comparison with the WN virus (Nigeria) strain revealed considerable divergence of the E protein at the nucleotide and amino acid levels.

  16. Analysis of jaagsiekte sheep retrovirus (JSRV) envelope protein domains in transformation.

    Science.gov (United States)

    Hull, Stacey; Lim, Joohyun; Hamil, Alexander; Nitta, Takayuki; Fan, Hung

    2012-12-01

    Jaagsiekte sheep retrovirus (JSRV) is the causative agent of a transmissible lung cancer in sheep. A unique feature is that JSRV envelope protein is also the oncogene for this virus. Previous studies have identified the cytoplasmic tail (CT) of the envelope transmembrane (TM) protein as critical for transformation although other regions of Env have also been implicated. In this study, the roles of other Env regions in transformation were investigated. Chimeras between JSRV Env and the Env of a related non-oncogenic endogenous retrovirus (enJSRV, 5F16) were used. A chimera containing the membrane-spanning region (MSR) of enJSRV inserted into JSRV Env showed substantially reduced transformation, indicating that the MSR plays a role in transformation. Transformation by this chimera was highly dependent on both Ras/Raf/MEK/MAPK and PI3K/Akt/mTOR signaling. A chimera containing the two amino acids in the TM ectodomain that distinguish JSRV and enJSRV showed modestly reduced transformation. Chimeras in the SU protein indicated that the amino terminal region of SU contributes to transformation, while the C-terminal part is not important. To test if Env trimerization is important for transformation, we mutated a leucine-rich sequence in the putative trimerization domain in the ectodomain of TM (Tri-M). This mutant could not transform cells and it did not oligomerize. However, Tri-M could complement a non-transforming mutant CT mutant (Y590F) so oligomerization is not necessary for at least some aspects of transformation. These experiments provide new insight into the regions and residues of JSRV Env protein necessary for oncogenic transformation.

  17. Oral and parenteral immunization of chickens (Gallus gallus) against West Nile virus with recombinant envelope protein

    Science.gov (United States)

    Fassbinder-Orth, C. A.; Hofmeister, Erik K.; Weeks-Levy, C.; Karasov, W.H.

    2009-01-01

    West Nile virus (WNV) causes morbidity and mortality in humans, horses, and in more than 315 bird species in North America. Currently approved WNV vaccines are designed for parenteral administration and, as yet, no effective oral WNV vaccines have been developed. WNV envelope (E) protein is a highly antigenic protein that elicits the majority of virus-neutralizing antibodies during a WNV immune response. Leghorn chickens were given three vaccinations (each 2 wk apart) of E protein orally (20 ??g or 100 ??g/dose), of E protein intramuscularly (IM, 20 ??g/dose), or of adjuvant only (control group) followed by a WNV challenge. Viremias were measured post-WNV infection, and three new enzyme-linked immunosorbent assays were developed for quantifying IgM, IgY, and IgA-mediated immune response of birds following WNV infection. WNV viremia levels were significantly lower in the IM group than in both oral groups and the control group. Total WNV E protein-specific IgY production was significantly greater, and WNV nonstructural 1-specific IgY was significantly less, in the IM group compared to all other treatment groups. The results of this study indicate that IM vaccination of chickens with E protein is protective against WNV infection and results in a significantly different antibody production profile as compared to both orally vaccinated and nonvaccinated birds. ?? 2009 American Association of Avian Pathologists.

  18. In Vitro Assembly and Stabilization of Dengue and Zika Virus Envelope Protein Homo-Dimers.

    Science.gov (United States)

    Metz, Stefan W; Gallichotte, Emily N; Brackbill, Alex; Premkumar, Lakshmanane; Miley, Michael J; Baric, Ralph; de Silva, Aravinda M

    2017-07-03

    Zika virus (ZIKV) and the 4 dengue virus (DENV) serotypes are mosquito-borne Flaviviruses that are associated with severe neuronal and hemorrhagic syndromes. The mature flavivirus infectious virion has 90 envelope (E) protein homo-dimers that pack tightly to form a smooth protein coat with icosahedral symmetry. Human antibodies that strongly neutralize ZIKV and DENVs recognize complex quaternary structure epitopes displayed on E-homo-dimers and higher order structures. The ZIKV and DENV E protein expressed as a soluble protein is mainly a monomer that does not display quaternary epitopes, which may explain the modest success with soluble recombinant E (sRecE) as a vaccine and diagnostic antigen. New strategies are needed to design recombinant immunogens that display these critical immune targets. Here we present two novel methods for building or stabilizing in vitro E-protein homo-dimers that display quaternary epitopes. In the first approach we immobilize sRecE to enable subsequent dimer generation. As an alternate method, we describe the use of human mAbs to stabilize homo-dimers in solution. The ability to produce recombinant E protein dimers displaying quaternary structure epitopes is an important advance with applications in flavivirus diagnostics and vaccine development.

  19. Surfactant protein D binds to human immunodeficiency virus (HIV) envelope protein gp120 and inhibits HIV replication

    DEFF Research Database (Denmark)

    Meschi, Joseph; Crouch, Erika C; Skolnik, Paul

    2005-01-01

    The envelope protein (gp120) of human immunodeficiency virus (HIV) contains highly conserved mannosylated oligosaccharides. These glycoconjugates contribute to resistance to antibody neutralization, and binding to cell surface lectins on macrophages and dendritic cells. Mannose-binding lectin (MBL......) binds to gp120 and plays a role in defence against the virus. In this study it is demonstrated that surfactant protein D (SP-D) binds to gp120 and inhibits HIV infectivity at significantly lower concentrations than MBL. The binding of SP-D was mediated by its calcium-dependent carbohydrate...... defence against HIV. A chimeric protein containing the N-terminal and collagen domains of SP-D linked to the neck and carbohydrate-recognition domains of MBL (called SP-D/MBL(neck+CRD)) had greater ability to bind to gp120 and inhibit virus replication than either SP-D or MBL. The enhanced binding of SP...

  20. TIM-family proteins promote infection of multiple enveloped viruses through virion-associated phosphatidylserine.

    Directory of Open Access Journals (Sweden)

    Stephanie Jemielity

    2013-03-01

    Full Text Available Human T-cell Immunoglobulin and Mucin-domain containing proteins (TIM1, 3, and 4 specifically bind phosphatidylserine (PS. TIM1 has been proposed to serve as a cellular receptor for hepatitis A virus and Ebola virus and as an entry factor for dengue virus. Here we show that TIM1 promotes infection of retroviruses and virus-like particles (VLPs pseudotyped with a range of viral entry proteins, in particular those from the filovirus, flavivirus, New World arenavirus and alphavirus families. TIM1 also robustly enhanced the infection of replication-competent viruses from the same families, including dengue, Tacaribe, Sindbis and Ross River viruses. All interactions between TIM1 and pseudoviruses or VLPs were PS-mediated, as demonstrated with liposome blocking and TIM1 mutagenesis experiments. In addition, other PS-binding proteins, such as Axl and TIM4, promoted infection similarly to TIM1. Finally, the blocking of PS receptors on macrophages inhibited the entry of Ebola VLPs, suggesting that PS receptors can contribute to infection in physiologically relevant cells. Notably, infection mediated by the entry proteins of Lassa fever virus, influenza A virus and SARS coronavirus was largely unaffected by TIM1 expression. Taken together our data show that TIM1 and related PS-binding proteins promote infection of diverse families of enveloped viruses, and may therefore be useful targets for broad-spectrum antiviral therapies.

  1. TIM-family proteins promote infection of multiple enveloped viruses through virion-associated phosphatidylserine.

    Science.gov (United States)

    Jemielity, Stephanie; Wang, Jinyize J; Chan, Ying Kai; Ahmed, Asim A; Li, Wenhui; Monahan, Sheena; Bu, Xia; Farzan, Michael; Freeman, Gordon J; Umetsu, Dale T; Dekruyff, Rosemarie H; Choe, Hyeryun

    2013-03-01

    Human T-cell Immunoglobulin and Mucin-domain containing proteins (TIM1, 3, and 4) specifically bind phosphatidylserine (PS). TIM1 has been proposed to serve as a cellular receptor for hepatitis A virus and Ebola virus and as an entry factor for dengue virus. Here we show that TIM1 promotes infection of retroviruses and virus-like particles (VLPs) pseudotyped with a range of viral entry proteins, in particular those from the filovirus, flavivirus, New World arenavirus and alphavirus families. TIM1 also robustly enhanced the infection of replication-competent viruses from the same families, including dengue, Tacaribe, Sindbis and Ross River viruses. All interactions between TIM1 and pseudoviruses or VLPs were PS-mediated, as demonstrated with liposome blocking and TIM1 mutagenesis experiments. In addition, other PS-binding proteins, such as Axl and TIM4, promoted infection similarly to TIM1. Finally, the blocking of PS receptors on macrophages inhibited the entry of Ebola VLPs, suggesting that PS receptors can contribute to infection in physiologically relevant cells. Notably, infection mediated by the entry proteins of Lassa fever virus, influenza A virus and SARS coronavirus was largely unaffected by TIM1 expression. Taken together our data show that TIM1 and related PS-binding proteins promote infection of diverse families of enveloped viruses, and may therefore be useful targets for broad-spectrum antiviral therapies.

  2. Cell envelope of Bordetella pertussis: immunological and biochemical analyses and characterization of a major outer membrane porin protein

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, S.K.

    1986-01-01

    Surface molecules of Bordetella pertussis which may be important in metabolism, pathogenesis, and immunity to whooping cough were examined using cell fractionation and /sup 125/I cell surface labeling. Antigenic envelope proteins were examined by immunofluorescence microscopy and Western blotting procedures using monoclonal antibodies and convalescent sera. A surface protein with a high M/sub r/, missing in a mutant lacking the filamentous hemagglutinin, was identified in virulent Bordetella pertussis but was absent in virulent B. pertussis strains. At least three envelope proteins were found only in virulent B. pertussis strains and were absent or diminished in avirulent and most phenotypically modulated strains. Transposon-induced mutants unable to produce hemolysin, dermonecrotic toxin, pertussis toxin, and filamentous hemagglutinin also lacked these three envelope proteins, confirming that virulence-associated envelope proteins were genetically regulated with other virulence-associated traits. Two dimensional gel electrophoresis revealed at least five heat modifiable proteins which migrated as higher or lower M/sub r/ moieties if solubilized at 25/sup 0/C instead of 100/sup 0/C.

  3. Zika Virus Encoding Non-Glycosylated Envelope Protein is Attenuated and Defective in Neuroinvasion.

    Science.gov (United States)

    Annamalai, Arun S; Pattnaik, Aryamav; Sahoo, Bikash R; Muthukrishnan, Ezhumalai; Natarajan, Sathish Kumar; Steffen, David; Vu, Hiep L X; Delhon, Gustavo; Osorio, Fernando A; Petro, Thomas M; Xiang, Shi-Hua; Pattnaik, Asit K

    2017-09-20

    Zika virus (ZIKV), a mosquito-transmitted flavivirus, responsible for sporadic outbreaks of mild and febrile illness in Africa and Asia, re-emerged in the last decade causing serious human diseases including microcephaly, congenital malformations, and Guillain-Barré syndrome. Although genomic and phylogenetic analyses suggest that genetic evolution may have led to enhanced virulence of ZIKV, experimental evidence supporting the role of specific genetic changes in virulence is currently outstanding. One sequence motif, VNDT, containing an N-linked glycosylation site in the envelope (E) protein, is polymorphic, being absent in many of the African isolates while present in all isolates from the recent outbreaks. In the present study, we interrogated the role of this sequence motif and glycosylation of the E protein in pathogenicity of ZIKV. We first constructed a stable full-length cDNA clone of ZIKV in a novel linear vector from which infectious virus was recovered. The recombinant ZIKV generated from the infectious clone, which contains the VNDT motif, is highly pathogenic and causes lethality in a mouse model. In contrast, recombinant viruses from which the VNDT motif is deleted or from which N-linked glycosylation site is mutated by single amino acid substitution, are highly attenuated and non-lethal. The mutant viruses replicate poorly in the brain of infected mice when inoculated subcutaneously but replicate well following intracranial inoculation. Our findings provide the first evidence that N-linked glycosylation of the E protein is an important determinant of ZIKV virulence and neuroinvasion.IMPORTANCE Recent emergence of Zika virus (ZIKV) in the Americas has caused major worldwide public health concern. The virus appears to have gained significant pathogenicity, causing serious human diseases including microcephaly and Guillain-Barré syndrome. The factors responsible for the emergence of pathogenic ZIKV are not understood at this time, although genetic

  4. Mapping of a neutralizing epitope in the surface envelope protein of porcine endogenous retrovirus subgroup B.

    Science.gov (United States)

    Nakaya, Yuki; Hoshino, Shigeki; Yasuda, Jiro; Miyazawa, Takayuki

    2011-04-01

    Pigs are thought to be the most suitable donor animal for xenotransplantation. However, pigs harbour potentially hazardous infectious agents, termed porcine endogenous retroviruses (PERVs), in their genome. In this study, we generated a mAb against PERV-B surface (SU) envelope protein (Env), designated KRT1. KRT1 binding was detected by an indirect immunofluorescence assay and flow cytometric analysis on cells infected with PERV-B. KRT1 neutralized PERV-B pseudotype virus and specifically recognized PERV-B SU Env, but not PERV-A SU Env by immunoblotting analysis. The peptide-ELISA revealed that KRT1 recognized a linear peptide sequence (ALEPPHNLPVP) residing in a proline-rich region that is one of the subdomains of SU Env. In conclusion, the KRT1 antibody will serve as a useful tool for the study of PERV-B and, more importantly, it may provide new protective strategies against PERV-B infection in xenotransplantation.

  5. Experimental and computational surface hydrophobicity analysis of a non-enveloped virus and proteins.

    Science.gov (United States)

    Heldt, Caryn L; Zahid, Amna; Vijayaragavan, K Saagar; Mi, Xue

    2017-05-01

    The physical characteristics of viruses needs to be understood in order to manipulate the interaction of viruses with host cells, as well as to create specific molecular recognition techniques to detect, purify, and remove viruses. Viruses are generally believed to be positively charged at physiological pH, but there are few other defining characteristics. Here, we have experimentally and computationally demonstrated that a non-enveloped virus is more hydrophobic than a panel of model proteins. Reverse-phase and hydrophobic interaction chromatography and ANS fluorescence determined the experimental hydrophobic strength of each entity. Computational surface hydrophobicity was calculated by the solvent exposed surface area of the protein weighted by the hydrophobicity of each amino acid. The results obtained indicate a strong correlation between the computational surface hydrophobicity and experimentally determined hydrophobicity using reverse-phase chromatography and ANS fluorescence. The surface hydrophobicity did not compare strongly to the weighted average of the amino acid sequence hydrophobicity. This demonstrates that our simple method of calculating the surface hydrophobicity gives general hydrophobicity information about proteins and viruses with crystal structures. In the process, this method demonstrated that porcine parvovirus (PPV) is more hydrophobic than the model proteins used in this study. This adds an additional dimension to currently known virus characteristics and can improve our manipulation of viruses for gene therapy targeting, surface adsorption and general understanding of virus interactions. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. IFITM Proteins Restrict HIV-1 Infection by Antagonizing the Envelope Glycoprotein

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    Jingyou Yu

    2015-10-01

    Full Text Available The interferon-induced transmembrane (IFITM proteins have been recently shown to restrict HIV-1 and other viruses. Here, we provide evidence that IFITM proteins, particularly IFITM2 and IFITM3, specifically antagonize the HIV-1 envelope glycoprotein (Env, thereby inhibiting viral infection. IFITM proteins interact with HIV-1 Env in viral producer cells, leading to impaired Env processing and virion incorporation. Notably, the level of IFITM incorporation into HIV-1 virions does not strictly correlate with the extent of inhibition. Prolonged passage of HIV-1 in IFITM-expressing T lymphocytes leads to emergence of Env mutants that overcome IFITM restriction. The ability of IFITMs to inhibit cell-to-cell infection can be extended to HIV-1 primary isolates, HIV-2 and SIVs; however, the extent of inhibition appears to be virus-strain dependent. Overall, our study uncovers a mechanism by which IFITM proteins specifically antagonize HIV-1 Env to restrict HIV-1 infection and provides insight into the specialized role of IFITMs in HIV infection.

  7. Development of envelope protein antigens to serologically differentiate Zika from dengue virus infection.

    Science.gov (United States)

    Premkumar, Lakshmanane; Collins, Matthew; Graham, Stephen; Liou, Guei-Jiun Alice; Lopez, Cesar A; Jadi, Ramesh; Balmaseda, Angel; Brackbill, James A; Dietze, Reynaldo; Camacho, Erwin; De Silva, Aruna D; Giuberti, Camila; Dos Reis, Helena Lucia; Singh, Tulika; Heimsath, Holly; Weiskopf, Daniela; Sette, Alessandro; Osorio, Jorge E; Permar, Sallie R; Miley, Michel J; Lazear, Helen M; Harris, Eva; de Silva, Aravinda M

    2017-12-20

    Zika virus (ZIKV) is an emerging flavivirus that can cause birth defects and neurologic complications. Molecular tests are effective in diagnosing acute ZIKV infection, although the majority of infections produce no symptoms at all or present after the narrow window in which molecular diagnostics are dependable. Serology is a reliable method for detecting infections after the viremic period; however, most serological assays have limited specificity due to cross-reactive antibodies elicited by flavivirus infections. Since ZIKV and dengue virus (DENV) widely co-circulate, distinguishing ZIKV from DENV infection is particularly important for diagnosing individual cases or surveillance to coordinate public health response. Flaviviruses also elicit type-specific antibodies directed to non-cross-reactive epitopes of the infecting virus; such epitopes are attractive targets for designing antigens to develop serologic tests with greater specificity. Guided by comparative epitope modeling of ZIKV envelope protein, we designed two recombinant antigens displaying unique antigenic regions on domain I (Z-EDI) and domain III (Z-EDIII) of ZIKV envelope protein. Both Z-EDI and Z-EDIII antigens consistently detected ZIKV-specific IgG in ZIKV-immune sera but not cross-reactive IgG in DENV-immune sera in late convalescence (>12 weeks post-infection). In contrast, during early convalescence (2-12 weeks post-infection), secondary DENV-immune sera and some primary DENV-immune sera cross-reacted with Z-EDI and Z-EDIII antigens. Analysis of sequential samples from DENV-immune individuals demonstrated that Z-EDIII cross-reactivity peaked in the early convalescence and steeply declined over time. The Z-EDIII antigen has much potential as a diagnostic antigen for population level surveillance and for detecting past infections in patients. Copyright © 2017 American Society for Microbiology.

  8. Coupling of receptor interference and a host-dependent post-binding entry deficiency in a gammaretroviral envelope protein

    Directory of Open Access Journals (Sweden)

    Sørensen Karina

    2010-02-01

    Full Text Available Abstract Background SL3-2 is a unique polytropic murine gammaretroviral isolate that is only able to infect murine cells. We have previously shown that two mutations R212G and T213I located on the surface of the receptor binding domain in a region designated the VR3 loop can alter the species tropism of this envelope protein. This location suggests that the VR3 loop composition has an influence on receptor interaction and thereby affects binding as well as superinfection resistance. In order to investigate this further, we have studied the binding and interference patterns of the SL3-2 envelope and its mutants. Results We find unexpectedly that wild type SL3-2 envelope binds equally well to both permissive and non-permissive cells, indicating a post binding defect when interacting with the human Xpr1. Using replication competent viruses containing envelopes from SL3-2 or its mutants we find that the same amino acid mutations can dramatically alter the interference profile of this polytropic ENV, suggesting that the same amino acid changes that cause the post binding defect also influence interaction with the receptor. Conclusions The envelope protein of SL3-2 MLV shows an entry defect on non-murine cells. This is coupled to a dramatically reduced ability to interfere with entry of other polytropic viruses. Two point mutations in the VR3 loop of the receptor binding domain of this envelope result both in a much increased interference ability and in removing the post-binding defect on non-murine cells, suggesting that both of these phenotypes are a consequence of insufficient interaction between the envelope and the receptor

  9. Novel interactions of domain III from the envelope glycoprotein of dengue 2 virus with human plasma proteins.

    Science.gov (United States)

    Huerta, Vivian; Ramos, Yassel; Yero, Alexis; Pupo, Dianne; Martín, Dayron; Toledo, Patricia; Fleitas, Noralvis; Gallien, Sebastien; Martín, Alejandro M; Márquez, Gabriel J; Pérez-Riverol, Yasset; Sarría, Mónica; Guirola, Osmany; González, Luis J; Domon, Bruno; Chinea, Glay

    2016-01-10

    Blood cells and plasma are important media for the four serotypes of dengue virus (DENV1-4) spreading into an infected person. Thus, interactions with human plasma proteins are expected to be decisive in the course of the viral infection. Affinity purification followed by MS analysis (AP/MS) was used to isolate and identify plasma-derived proteins capable to interact with a recombinant protein comprising the domain III of the envelope protein of DENV2 (DIIIE2). The elution of the AP potently inhibits DENV2 infection. Twenty-nine proteins were identified using a label-free approach as specifically captured by DIIIE2. Of these, a direct interaction with C reactive protein, thrombin and Inter-alpha-inhibitor complexes was confirmed by ELISA. Results provide further evidence of a significant representation of proteins from complement and coagulation cascades on DENV2 interactome in human plasma and stand out the domain III of the viral envelope protein as participant on these interactions. A functional clustering analysis highlights the presence of three structural motifs among putative DIIIE2-binding proteins: hydroxylation and EGF-like calcium-binding- and Gla domains. Early cycles of dengue virus replication take place in human blood cells. Thus, the characterization of the interactome of dengue virus proteins in human plasma can lead to the identification of pivotal interactions for the infection that can eventually constitute the target for the development of methods to control dengue virus-caused disease. In this work we identified 29 proteins from human plasma that potentially interact with the envelope protein of dengue 2 virus either directly or through co-complex formation. C reactive protein, thrombin and Inter-alpha-inhibitor complexes were validated as interactors of the domain III of the envelope protein of dengue 2. Results highlight the presence of three structural motifs among putative DIIIE2-binding proteins: hydroxylation and EGF-like calcium

  10. A single mutation in the envelope protein modulates flavivirus antigenicity, stability, and pathogenesis.

    Directory of Open Access Journals (Sweden)

    Leslie Goo

    2017-02-01

    Full Text Available The structural flexibility or 'breathing' of the envelope (E protein of flaviviruses allows virions to sample an ensemble of conformations at equilibrium. The molecular basis and functional consequences of virus conformational dynamics are poorly understood. Here, we identified a single mutation at residue 198 (T198F of the West Nile virus (WNV E protein domain I-II hinge that regulates virus breathing. The T198F mutation resulted in a ~70-fold increase in sensitivity to neutralization by a monoclonal antibody targeting a cryptic epitope in the fusion loop. Increased exposure of this otherwise poorly accessible fusion loop epitope was accompanied by reduced virus stability in solution at physiological temperatures. Introduction of a mutation at the analogous residue of dengue virus (DENV, but not Zika virus (ZIKV, E protein also increased accessibility of the cryptic fusion loop epitope and decreased virus stability in solution, suggesting that this residue modulates the structural ensembles sampled by distinct flaviviruses at equilibrium in a context dependent manner. Although the T198F mutation did not substantially impair WNV growth kinetics in vitro, studies in mice revealed attenuation of WNV T198F infection. Overall, our study provides insight into the molecular basis and the in vitro and in vivo consequences of flavivirus breathing.

  11. Structural and Functional Comparisons of Retroviral Envelope Protein C-Terminal Domains: Still Much to Learn

    Directory of Open Access Journals (Sweden)

    Jonathan D. Steckbeck

    2014-01-01

    Full Text Available Retroviruses are a family of viruses that cause a broad range of pathologies in animals and humans, from the apparently harmless, long-term genomic insertion of endogenous retroviruses, to tumors induced by the oncogenic retroviruses and acquired immunodeficiency syndrome (AIDS resulting from human immunodeficiency virus infection. Disease can be the result of diverse mechanisms, including tumorigenesis induced by viral oncogenes or immune destruction, leading to the gradual loss of CD4 T-cells. Of the virally encoded proteins common to all retroviruses, the envelope (Env displays perhaps the most diverse functionality. Env is primarily responsible for binding the cellular receptor and for effecting the fusion process, with these functions mediated by protein domains localized to the exterior of the virus. The remaining C-terminal domain may have the most variable functionality of all retroviral proteins. The C-terminal domains from three prototypical retroviruses are discussed, focusing on the different structures and functions, which include fusion activation, tumorigenesis and viral assembly and lifecycle influences. Despite these genetic and functional differences, however, the C-terminal domains of these viruses share a common feature in the modulation of Env ectodomain conformation. Despite their differences, perhaps each system still has information to share with the others.

  12. Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype.

    Science.gov (United States)

    Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

    2016-01-01

    Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis.

  13. West Nile virus envelope protein inhibits dsRNA-induced innate immune responses.

    Science.gov (United States)

    Arjona, Alvaro; Ledizet, Michel; Anthony, Karen; Bonafé, Nathalie; Modis, Yorgo; Town, Terrence; Fikrig, Erol

    2007-12-15

    The immune response against viral infection relies on the early production of cytokines that induce an antiviral state and trigger the activation of immune cells. This response is initiated by the recognition of virus-associated molecular patterns such as dsRNA, a viral replication intermediate recognized by TLR3 and certain RNA helicases. Infection with West Nile virus (WNV) can lead to lethal encephalitis in susceptible individuals and constitutes an emerging health threat. In this study, we report that WNV envelope protein (WNV-E) specifically blocks the production of antiviral and proinflammatory cytokines induced by dsRNA in murine macrophages. This immunosuppressive effect was not dependent on TLR3 or its adaptor molecule Trif. Instead, our experiments show that WNV-E acts at the level of receptor-interacting protein 1. Our results also indicate that WNV-E requires a certain glycosylation pattern, specifically that of dipteran cells, to inhibit dsRNA-induced cytokine production. In conclusion, these data show that the major structural protein of WNV impairs the innate immune response and suggest that WNV exploits differential vector/host E glycosylation profiles to evade antiviral mechanisms.

  14. Species, biotype, and bacteriophage type determinations compared with cell envelope protein profiles for typing Acinetobacter strains.

    Science.gov (United States)

    Bouvet, P J; Jeanjean, S; Vieu, J F; Dijkshoorn, L

    1990-02-01

    Species, biotypes, and phage types were determined for 120 Acinetobacter strains from clinical or environmental sources or from culture collections. These characteristics were compared with cell envelope protein profiles obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in previous studies. A considerable heterogeneity of species and types was observed by use of the various methods, in particular among strains from different sources. Acinetobacter baumannii was the most commonly found species in isolates from clinical sources, followed by Acinetobacter species 3. Nine biotypes were observed among A. baumannii strains. Further differentiation within most species and biotypes was achieved by protein profile typing and, to some extent, phage typing. Of 120 strains, 49 (41%) were not typeable by phages. Consistent results for the various classification methods were obtained for strains from common sources. Biotyping seemed an appropriate method for the screening of strains, whereas protein profile and phage typing could serve as additional methods to establish the identity or nonidentity of strains. Results of this study suggest that the combination of the typing methods is useful in epidemiological studies.

  15. Recovery of West Nile Virus Envelope Protein Domain III Chimeras with Altered Antigenicity and Mouse Virulence.

    Science.gov (United States)

    McAuley, Alexander J; Torres, Maricela; Plante, Jessica A; Huang, Claire Y-H; Bente, Dennis A; Beasley, David W C

    2016-05-01

    Flaviviruses are positive-sense, single-stranded RNA viruses responsible for millions of human infections annually. The envelope (E) protein of flaviviruses comprises three structural domains, of which domain III (EIII) represents a discrete subunit. The EIII gene sequence typically encodes epitopes recognized by virus-specific, potently neutralizing antibodies, and EIII is believed to play a major role in receptor binding. In order to assess potential interactions between EIII and the remainder of the E protein and to assess the effects of EIII sequence substitutions on the antigenicity, growth, and virulence of a representative flavivirus, chimeric viruses were generated using the West Nile virus (WNV) infectious clone, into which EIIIs from nine flaviviruses with various levels of genetic diversity from WNV were substituted. Of the constructs tested, chimeras containing EIIIs from Koutango virus (KOUV), Japanese encephalitis virus (JEV), St. Louis encephalitis virus (SLEV), and Bagaza virus (BAGV) were successfully recovered. Characterization of the chimeras in vitro and in vivo revealed differences in growth and virulence between the viruses, within vivo pathogenesis often not being correlated within vitro growth. Taken together, the data demonstrate that substitutions of EIII can allow the generation of viable chimeric viruses with significantly altered antigenicity and virulence. The envelope (E) glycoprotein is the major protein present on the surface of flavivirus virions and is responsible for mediating virus binding and entry into target cells. Several viable West Nile virus (WNV) variants with chimeric E proteins in which the putative receptor-binding domain (EIII) sequences of other mosquito-borne flaviviruses were substituted in place of the WNV EIII were recovered, although the substitution of several more divergent EIII sequences was not tolerated. The differences in virulence and tissue tropism observed with the chimeric viruses indicate a

  16. Structure and inhibition of the SARS coronavirus envelope protein ion channel.

    Directory of Open Access Journals (Sweden)

    Konstantin Pervushin

    2009-07-01

    Full Text Available The envelope (E protein from coronaviruses is a small polypeptide that contains at least one alpha-helical transmembrane domain. Absence, or inactivation, of E protein results in attenuated viruses, due to alterations in either virion morphology or tropism. Apart from its morphogenetic properties, protein E has been reported to have membrane permeabilizing activity. Further, the drug hexamethylene amiloride (HMA, but not amiloride, inhibited in vitro ion channel activity of some synthetic coronavirus E proteins, and also viral replication. We have previously shown for the coronavirus species responsible for severe acute respiratory syndrome (SARS-CoV that the transmembrane domain of E protein (ETM forms pentameric alpha-helical bundles that are likely responsible for the observed channel activity. Herein, using solution NMR in dodecylphosphatidylcholine micelles and energy minimization, we have obtained a model of this channel which features regular alpha-helices that form a pentameric left-handed parallel bundle. The drug HMA was found to bind inside the lumen of the channel, at both the C-terminal and the N-terminal openings, and, in contrast to amiloride, induced additional chemical shifts in ETM. Full length SARS-CoV E displayed channel activity when transiently expressed in human embryonic kidney 293 (HEK-293 cells in a whole-cell patch clamp set-up. This activity was significantly reduced by hexamethylene amiloride (HMA, but not by amiloride. The channel structure presented herein provides a possible rationale for inhibition, and a platform for future structure-based drug design of this potential pharmacological target.

  17. Prm3p is a pheromone-induced peripheral nuclear envelope protein required for yeast nuclear fusion.

    Science.gov (United States)

    Shen, Shu; Tobery, Cynthia E; Rose, Mark D

    2009-05-01

    Nuclear membrane fusion is the last step in the mating pathway of the yeast Saccharomyces cerevisiae. We adapted a bioinformatics approach to identify putative pheromone-induced membrane proteins potentially required for nuclear membrane fusion. One protein, Prm3p, was found to be required for nuclear membrane fusion; disruption of PRM3 caused a strong bilateral defect, in which nuclear congression was completed but fusion did not occur. Prm3p was localized to the nuclear envelope in pheromone-responding cells, with significant colocalization with the spindle pole body in zygotes. A previous report, using a truncated protein, claimed that Prm3p is localized to the inner nuclear envelope. Based on biochemistry, immunoelectron microscopy and live cell microscopy, we find that functional Prm3p is a peripheral membrane protein exposed on the cytoplasmic face of the outer nuclear envelope. In support of this, mutations in a putative nuclear localization sequence had no effect on full-length protein function or localization. In contrast, point mutations and deletions in the highly conserved hydrophobic carboxy-terminal domain disrupted both protein function and localization. Genetic analysis, colocalization, and biochemical experiments indicate that Prm3p interacts directly with Kar5p, suggesting that nuclear membrane fusion is mediated by a protein complex.

  18. Structures of the Zika Virus Envelope Protein and Its Complex with a Flavivirus Broadly Protective Antibody.

    Science.gov (United States)

    Dai, Lianpan; Song, Jian; Lu, Xishan; Deng, Yong-Qiang; Musyoki, Abednego Moki; Cheng, Huijun; Zhang, Yanfang; Yuan, Yuan; Song, Hao; Haywood, Joel; Xiao, Haixia; Yan, Jinghua; Shi, Yi; Qin, Cheng-Feng; Qi, Jianxun; Gao, George F

    2016-05-11

    Zika virus (ZIKV), a mosquito-borne flavivirus, is a current global public health concern. The flavivirus envelope (E) glycoprotein is responsible for virus entry and represents a major target of neutralizing antibodies for other flaviviruses. Here, we report the structures of ZIKV E protein at 2.0 Å and in complex with a flavivirus broadly neutralizing murine antibody 2A10G6 at 3.0 Å. ZIKV-E resembles all the known flavivirus E structures but contains a unique, positively charged patch adjacent to the fusion loop region of the juxtaposed monomer, which may influence host attachment. The ZIKV-E-2A10G6 complex structure reveals antibody recognition of a highly conserved fusion loop. 2A10G6 binds to ZIKV-E with high affinity in vitro and neutralizes currently circulating ZIKV strains in vitro and in mice. The E protein fusion loop epitope represents a potential candidate for therapeutic antibodies against ZIKV. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Antigenic and immunosuppressive properties of a trimeric recombinant transmembrane envelope protein gp41 of HIV-1.

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    Michael Mühle

    Full Text Available The transmembrane envelope (TM protein gp41 of the human immunodeficiency virus-1 (HIV-1 plays an important role during virus infection inducing the fusion of the viral and cellular membranes. In addition, there are indications that the TM protein plays a role in the immunopathogenesis leading to the acquired immunodeficiency syndrome (AIDS. Inactivated virus particles and recombinant gp41 have been reported to inhibit lymphocyte proliferation, as well as to alter cytokine release and gene expression. The same was shown for a peptide corresponding to a highly conserved domain of all retroviral TM proteins, the immunosuppressive domain. Due to its propensity to aggregate and to be expressed at low levels, studies comprising authentic gp41 produced in eukaryotic cells are extremely rare. Here we describe the production of a secreted, soluble recombinant gp41 in 293 cells. The antigen was purified to homogeneity and characterised thoroughly by various biochemical and immunological methods. It was shown that the protein was glycosylated and assembled into trimers. Binding studies by ELISA and surface plasmon resonance using conformation-specific monoclonal antibodies implied a six-helix bundle conformation. The low binding of broadly neutralising antibodies (bnAb directed against the membrane proximal external region (MPER suggested that this gp41 is probably not suited as vaccine to induce such bnAb. Purified gp41 bound to monocytes and to a lesser extent to lymphocytes and triggered the production of specific cytokines when added to normal peripheral blood mononuclear cells. In addition, gp41 expressed on target cells inhibited the antigen-specific response of murine CD8+ T cells by drastically impairing their IFNγ production. To our knowledge, this is the first comprehensive analysis of a gp41 produced in eukaryotic cells including its immunosuppressive properties. Our data provide another line of evidence that gp41 might be directly involved in

  20. Glycosylation and oligomeric state of envelope protein might influence HIV-1 virion capture by α4β7 integrin.

    Science.gov (United States)

    Chand, Subhash; Messina, Emily L; AlSalmi, Wadad; Ananthaswamy, Neeti; Gao, Guofen; Uritskiy, Gherman; Padilla-Sanchez, Victor; Mahalingam, Marthandan; Peachman, Kristina K; Robb, Merlin L; Rao, Mangala; Rao, Venigalla B

    2017-08-01

    The α4ß7 integrin present on host cells recognizes the V1V2 domain of the HIV-1 envelope protein. This interaction might be involved in virus transmission. Administration of α4ß7-specific antibodies inhibit acquisition of SIV in a macaque challenge model. But the molecular details of V1V2: α4ß7 interaction are unknown and its importance in HIV-1 infection remains controversial. Our biochemical and mutational analyses show that glycosylation is a key modulator of V1V2 conformation and binding to α4ß7. Partially glycosylated, but not fully glycosylated, envelope proteins are preferred substrates for α4ß7 binding. Surprisingly, monomers of the envelope protein bound strongly to α4ß7 whereas trimers bound poorly. Our results suggest that a conformationally flexible V1V2 domain allows binding of the HIV-1 virion to the α4ß7 integrin, which might impart selectivity for the poorly glycosylated HIV-1 envelope containing monomers to be more efficiently captured by α4ß7 integrin present on mucosal cells at the time of HIV-1 transmission. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Severe acute respiratory syndrome coronavirus envelope protein regulates cell stress response and apoptosis.

    Directory of Open Access Journals (Sweden)

    Marta L DeDiego

    2011-10-01

    Full Text Available Severe acute respiratory syndrome virus (SARS-CoV that lacks the envelope (E gene (rSARS-CoV-ΔE is attenuated in vivo. To identify factors that contribute to rSARS-CoV-ΔE attenuation, gene expression in cells infected by SARS-CoV with or without E gene was compared. Twenty-five stress response genes were preferentially upregulated during infection in the absence of the E gene. In addition, genes involved in signal transduction, transcription, cell metabolism, immunoregulation, inflammation, apoptosis and cell cycle and differentiation were differentially regulated in cells infected with rSARS-CoV with or without the E gene. Administration of E protein in trans reduced the stress response in cells infected with rSARS-CoV-ΔE or with respiratory syncytial virus, or treated with drugs, such as tunicamycin and thapsigargin that elicit cell stress by different mechanisms. In addition, SARS-CoV E protein down-regulated the signaling pathway inositol-requiring enzyme 1 (IRE-1 of the unfolded protein response, but not the PKR-like ER kinase (PERK or activating transcription factor 6 (ATF-6 pathways, and reduced cell apoptosis. Overall, the activation of the IRE-1 pathway was not able to restore cell homeostasis, and apoptosis was induced probably as a measure to protect the host by limiting virus production and dissemination. The expression of proinflammatory cytokines was reduced in rSARS-CoV-ΔE-infected cells compared to rSARS-CoV-infected cells, suggesting that the increase in stress responses and the reduction of inflammation in the absence of the E gene contributed to the attenuation of rSARS-CoV-ΔE.

  2. Use of the hemagglutinating virus of Japan (HVJ) envelope as a versatile delivery system for nucleic acids and proteins to leukocytes in vitro.

    Science.gov (United States)

    Kondo, Yoshitaka; Miyata, Keizo; Kato, Fuminori

    2010-04-01

    The hemagglutinating virus of Japan (HVJ; also called the Sendai virus) envelope has been developed as a safe and efficient non-viral vector. Because replication and transcription of genomic RNA is inactivated by beta-propiolactone treatment or UV-irradiation, the HVJ envelope is extremely safe. This unit describes the method of transfection of siRNA and protein with the HVJ envelope. (c) 2010 by John Wiley & Sons, Inc.

  3. CD-loop Extension in Zika Virus Envelope Protein Key for Stability and Pathogenesis.

    Science.gov (United States)

    Gallichotte, Emily N; Dinnon, Kenneth H; Lim, Xin-Ni; Ng, Thiam-Seng; Lim, Elisa X Y; Menachery, Vineet D; Lok, Shee-Mei; Baric, Ralph S

    2017-12-05

    With severe disease manifestations including microcephaly, congenital malformation, and Guillain-Barré syndrome, Zika virus (ZIKV) remains a persistent global public health threat. Despite antigenic similarities with dengue viruses, structural studies have suggested the extended CD-loop and hydrogen-bonding interaction network within the ZIKV envelope protein contribute to stability differences between the viral families. This enhanced stability may lead to the augmented infection, disease manifestation, and persistence in body fluids seen following ZIKV infection. To examine the role of these motifs in infection, we generated a series of ZIKV recombinant viruses that disrupted the hydrogen-bonding network (350A, 351A, and 350A/351A) or the CD-loop extension (Δ346). Our results demonstrate a key role for the ZIKV extended CD-loop in cell-type-dependent replication, virion stability, and in vivo pathogenesis. Importantly, the Δ346 mutant maintains similar antigenicity to wild-type virus, opening the possibility for its use as a live-attenuated vaccine platform for ZIKV and other clinically relevant flaviviruses. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  4. Susceptibility of domestic animals to a pseudotype virus bearing RD-114 virus envelope protein.

    Science.gov (United States)

    Miyaho, Rie Nakaoka; Nakagawa, So; Hashimoto-Gotoh, Akira; Nakaya, Yuki; Shimode, Sayumi; Sakaguchi, Shoichi; Yoshikawa, Rokusuke; Takahashi, Mahoko Ueda; Miyazawa, Takayuki

    2015-08-10

    Retroviral vectors are used for gene transduction into cells and have been applied to gene therapy. Retroviral vectors using envelope protein (Env) of RD-114 virus, a feline endogenous retrovirus, have been used for gene transduction. In this study, we investigated the susceptibility to RD-114 Env-pseudotyped virus in twelve domestic animals including cattle, sheep, horse, pig, dog, cat, ferret, mink, rabbit, rat, mouse, and quail. Comparison of nucleotide sequences of ASCT2 (SLC1A5), a receptor of RD-114 virus, in 10 mammalian and 2 avian species revealed that insertion and deletion events at the region C of ASCT2 where RD-114 viral Env interacts occurred independently in the mouse and rat lineage and in the chicken and quail lineage. By the pseudotype virus infection assay, we found that RD-114 Env-pseudotyped virus could efficiently infect all cell lines except those from mouse and rat. Furthermore, we confirmed that bovine ASCT2 (bASCT2) functions as a receptor for RD-114 virus infection. We also investigated bASCT2 mRNA expression in cattle tissues and found that it is expressed in various tissues including lung, spleen and kidney. These results indicate that retrovirus vectors with RD-114 virus Env can be used for gene therapy in large domestic animals in addition to companion animals such as cat and dog. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. An Alphavirus E2 Membrane-Proximal Domain Promotes Envelope Protein Lateral Interactions and Virus Budding

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    Emily A. Byrd

    2017-11-01

    Full Text Available Alphaviruses are members of a group of small enveloped RNA viruses that includes important human pathogens such as Chikungunya virus and the equine encephalitis viruses. The virus membrane is covered by a lattice composed of 80 spikes, each a trimer of heterodimers of the E2 and E1 transmembrane proteins. During virus endocytic entry, the E1 glycoprotein mediates the low-pH-dependent fusion of the virus membrane with the endosome membrane, thus initiating virus infection. While much is known about E1 structural rearrangements during membrane fusion, it is unclear how the E1/E2 dimer dissociates, a step required for the fusion reaction. A recent Alphavirus cryo-electron microscopy reconstruction revealed a previously unidentified D subdomain in the E2 ectodomain, close to the virus membrane. A loop within this region, here referred to as the D-loop, contains two highly conserved histidines, H348 and H352, which were hypothesized to play a role in dimer dissociation. We generated Semliki Forest virus mutants containing the single and double alanine substitutions H348A, H352A, and H348/352A. The three D-loop mutations caused a reduction in virus growth ranging from 1.6 to 2 log but did not significantly affect structural protein biosynthesis or transport, dimer stability, virus fusion, or specific infectivity. Instead, growth reduction was due to inhibition of a late stage of virus assembly at the plasma membrane. The virus particles that are produced show reduced thermostability compared to the wild type. We propose the E2 D-loop as a key region in establishing the E1-E2 contacts that drive glycoprotein lattice formation and promote Alphavirus budding from the plasma membrane.

  6. Comparative immunogenicity of HIV-1 clade C envelope proteins for prime/boost studies.

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    Douglas H Smith

    2010-08-01

    Full Text Available Previous clinical efficacy trials failed to support the continued development of recombinant gp120 (rgp120 as a candidate HIV vaccine. However, the recent RV144 HIV vaccine trial in Thailand showed that a prime/boost immunization strategy involving priming with canarypox vCP1521 followed by boosting with rgp120 could provide significant, although modest, protection from HIV infection. Based on these results, there is renewed interest in the development of rgp120 based antigens for follow up vaccine trials, where this immunization approach can be applied to other cohorts at high risk for HIV infection. Of particular interest are cohorts in Africa, India, and China that are infected with clade C viruses.A panel of 10 clade C rgp120 envelope proteins was expressed in 293 cells, purified by immunoaffinity chromatography, and used to immunize guinea pigs. The resulting sera were collected and analyzed in checkerboard experiments for rgp120 binding, V3 peptide binding, and CD4 blocking activity. Virus neutralization studies were carried out with two different assays and two different panels of clade C viruses. A high degree of cross reactivity against clade C and clade B viruses and viral proteins was observed. Most, but not all of the immunogens tested elicited antibodies that neutralized tier 1 clade B viruses, and some sera neutralized multiple clade C viruses. Immunization with rgp120 from the CN97001 strain of HIV appeared to elicit higher cross neutralizing antibody titers than the other antigens tested.While all of the clade C antigens tested were immunogenic, some were more effective than others in eliciting virus neutralizing antibodies. Neutralization titers did not correlate with rgp120 binding, V3 peptide binding, or CD4 blocking activity. CN97001 rgp120 elicited the highest level of neutralizing antibodies, and should be considered for further HIV vaccine development studies.

  7. Dengue-1 envelope protein domain III along with PELC and CpG oligodeoxynucleotides synergistically enhances immune responses.

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    Chen-Yi Chiang

    Full Text Available The major weaknesses of subunit vaccines are their low immunogenicity and poor efficacy. Adjuvants can help to overcome some of these inherent defects with subunit vaccines. Here, we evaluated the efficacy of the newly developed water-in-oil-in-water multiphase emulsion system, termed PELC, in potentiating the protective capacity of dengue-1 envelope protein domain III. Unlike aluminum phosphate, dengue-1 envelope protein domain III formulated with PELC plus CpG oligodeoxynucleotides induced neutralizing antibodies against dengue-1 virus and increased the splenocyte secretion of IFN-γ after in vitro re-stimulation. The induced antibodies contained both the IgG1 and IgG2a subclasses. A rapid anamnestic neutralizing antibody response against a live dengue virus challenge was elicited at week 26 after the first immunization. These results demonstrate that PELC plus CpG oligodeoxynucleotides broaden the dengue-1 envelope protein domain III-specific immune responses. PELC plus CpG oligodeoxynucleotides is a promising adjuvant for recombinant protein based vaccination against dengue virus.

  8. A peptide derived from hepatitis C virus E2 envelope protein inhibits a post-binding step in HCV entry.

    Science.gov (United States)

    Liu, R; Tewari, M; Kong, R; Zhang, R; Ingravallo, P; Ralston, R

    2010-05-01

    The HCV envelope proteins E1 and E2 are required for virus binding to cellular receptors and pH-dependent fusion with endosomal membranes. Envelope protein interactions within this multistep process may provide novel targets for development of antiviral agents. To identify E1 and E2 regions involved in critical steps of HCV entry, we screened an E1E2 overlapping peptide library for inhibition of infection using a lentiviral reporter vector pseudotyped with E1E2 envelope proteins. A 16-residue polypeptide containing a portion of the E2 transmembrane domain (Peptide 75) inhibited HCV pseudoparticle infection with an IC50 of approximately 0.3microM and did not inhibit infection by VSV-g pseudoparticles at concentrations up to 50microM. Structure-activity analysis of Peptide 75 showed that antiviral activity was dependent upon L-configuration and hydrophobic character, and that the native sequence was required for maximal activity. Peptide 75 did not show virocidal activity against HCV pseudoparticles or other viruses. Temperature-shift experiments showed that the peptide acted at a post-binding step and that inhibition was further increased when used in combination with an anti-CD81 antibody previously shown to inhibit pseudoparticle entry at a post-binding step. These data suggest that interactions involving the C terminal region of E2 may play an important role in the HCV entry process.

  9. Genotype-specific neutralization determinants in envelope protein: implications for the improvement of Japanese encephalitis vaccine.

    Science.gov (United States)

    Ye, Qing; Xu, Yan-Peng; Zhang, Yu; Li, Xiao-Feng; Wang, Hong-Jiang; Liu, Zhong-Yu; Li, Shi-Hua; Liu, Long; Zhao, Hui; Nian, Qing-Gong; Deng, Yong-Qiang; Qin, E-De; Qin, Cheng-Feng

    2015-08-01

    Japanese encephalitis remains the leading cause of viral encephalitis in children in Asia and is expanding its geographical range to larger areas in Asia and Australasia. Five genotypes of Japanese encephalitis virus (JEV) co-circulate in the geographically affected areas. In particular, the emergence of genotype I (GI) JEV has displaced genotype III (GIII) as the dominant circulating genotype in many Asian regions. However, all approved vaccine products are derived from GIII strains. In the present study, bioinformatic analysis revealed that GI and GIII JEV strains shared two distinct amino acid residues within the envelope (E) protein (E222 and E327). By using reverse genetics approaches, A222S and S327T mutations were demonstrated to decrease live-attenuated vaccine (LAV) SA14-14-2-induced neutralizing antibodies in humans, without altering viral replication. A222S or S327T mutations were then rationally engineered into the infectious clone of SA14-14-2, and the resulting mutant strains retained the same genetic stability and attenuation characteristics as the parent strain. More importantly, immunization of mice with LAV-A222S or LAV-S327T elicited increased neutralizing antibodies against GI strains. Together, these results demonstrated that E222 and E327 are potential genotype-related neutralization determinants and are critical in determining the protective efficacy of live Japanese encephalitis vaccine SA14-14-2 against circulating GI strains. Our findings will aid in the rational design of the next generation of Japanese encephalitis LAVs capable of providing broad protection against all JEV strains belonging to different genotypes.

  10. Components of the E. coli envelope are affected by and can react to protein over-production in the cytoplasm

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    Villa Riccardo

    2009-06-01

    Full Text Available Abstract Background Protein over-expression in bacteria is still the easiest, cheapest and therefore preferred way to obtain large amounts of proteins for industrial and laboratory scale preparations. Several studies emphasized the importance of understanding cellular and molecular mechanisms triggered by protein over-production in order to obtain higher yield and better quality of the recombinant product. Almost every step leading to a fully functional polypeptide has been investigated, from mRNA stability to the role of molecular chaperones, from aggregation to bottlenecks in the secretory pathway. In this context, we focused on the still poorly addressed relationship between protein production in the cytoplasm and the bacterial envelope, an active and reactive cell compartment that controls interactions with the environment and several major cellular processes. Results available to date show that the accumulation of foreign proteins in the cytoplasm induces changes in the membrane lipids and in the levels of mRNAs for some membrane proteins. However, a direct connection between membrane protein expression levels and soluble/aggregated protein accumulation in the cytoplasm has never been reported. Results By the use of a combined physiological and proteomic approach, we investigated the effects on the cell membrane of E. coli of the overexpression of two recombinant proteins, the B. cepacia lipase (BCL and the green fluorescent protein (GFP. Both polypeptides are expressed in the cytoplasm at similar levels but GFP is fully soluble whereas inactive BCL accumulates in inclusion bodies. Growth and viability of the transformed cells were tested in the presence of different drugs. We found that chloramphenycol preferentially inhibited the strain over-producing GFP while SDS was more effective when BCL inclusion bodies accumulated in the cytoplasm. In contrast, both proteins induced a similar response in the membrane proteome, i.e. increased levels

  11. The BDLF2 protein of Epstein-Barr virus is a type II glycosylated envelope protein whose processing is dependent on coexpression with the BMRF2 protein.

    Science.gov (United States)

    Gore, Mindy; Hutt-Fletcher, Lindsey M

    2009-01-05

    Epstein-Barr virus has been documented to encode for ten envelope glycoproteins, gB, gH, gL, gM, gN, gp350, gp42, gp78, gp150 and BMRF2. The BDLF2 open reading frame is also predicted to encode a type II membrane protein but, although found in the virion, it has been described as a component of the tegument. We show here that, as predicted, it is the eleventh envelope glycoprotein of the virus. The full length 65 kDa glycoprotein formed a complex with BMRF2 and, as its homologs in other gammaherpesviruses, was dependent on BMRF2, for authentic processing and transport. Two cleavage products of BDLF2 were also identified in cells and in purified virion particles, one corresponding approximately to the aminoterminal half of the protein, that remained associated with the full length form, and one corresponding to the carboxyterminal glycosylated portion of the protein which did not.

  12. The lamin B receptor of the nuclear envelope inner membrane: a polytopic protein with eight potential transmembrane domains

    OpenAIRE

    1990-01-01

    The lamin B receptor is a previously identified integral membrane protein in the nuclear envelope of turkey erythrocytes that associates with the nuclear intermediate filament protein lamin B (Worman, H. J., J. Yuan, G. Blobel, and S. D. Georgatos. 1988. Proc. Natl. Acad. Sci. USA. 85:8531-8534). In the present report, we use cell fractionation and antibodies against the lamin B receptor to localize it to an 8-M urea-extracted membrane fraction of chicken liver nuclei, supporting an inner nuc...

  13. Comparative proteomics of chloroplast envelopes from C3 and C4 plants reveals specific adaptations of the plastid envelope to C4 photosynthesis and candidate proteins required for maintaining C4 metabolite fluxes.

    Science.gov (United States)

    Bräutigam, Andrea; Hoffmann-Benning, Susanne; Hofmann-Benning, Susanne; Weber, Andreas P M

    2008-09-01

    C(4) plants have up to 10-fold higher apparent CO(2) assimilation rates than the most productive C(3) plants. This requires higher fluxes of metabolic intermediates across the chloroplast envelope membranes of C(4) plants in comparison with those of C(3) plants. In particular, the fluxes of metabolites involved in the biochemical inorganic carbon pump of C(4) plants, such as malate, pyruvate, oxaloacetate, and phosphoenolpyruvate, must be considerably higher in C(4) plants because they exceed the apparent rate of photosynthetic CO(2) assimilation, whereas they represent relatively minor fluxes in C(3) plants. While the enzymatic steps involved in the C(4) biochemical inorganic carbon pump have been studied in much detail, little is known about the metabolite transporters in the envelope membranes of C(4) chloroplasts. In this study, we used comparative proteomics of chloroplast envelope membranes from the C(3) plant pea (Pisum sativum) and mesophyll cell chloroplast envelopes from the C(4) plant maize (Zea mays) to analyze the adaptation of the mesophyll cell chloroplast envelope proteome to the requirements of C(4) photosynthesis. We show that C(3)- and C(4)-type chloroplasts have qualitatively similar but quantitatively very different chloroplast envelope membrane proteomes. In particular, translocators involved in the transport of triosephosphate and phosphoenolpyruvate as well as two outer envelope porins are much more abundant in C(4) plants. Several putative transport proteins have been identified that are highly abundant in C(4) plants but relatively minor in C(3) envelopes. These represent prime candidates for the transport of C(4) photosynthetic intermediates, such as pyruvate, oxaloacetate, and malate.

  14. Structure-function relationship of the baculovirus envelope fusion protein F

    NARCIS (Netherlands)

    Long, G.

    2007-01-01

    Baculoviruses are a large group of enveloped, double-stranded DNA viruses exclusively infectious for arthropods, predominantly insects of the order Lepidoptera. Baculovirology has advanced considerably in recent years as a consequence of the successful use of baculoviruses (i) in biological control

  15. Increased titers of neutralizing antibodies after immunization with both envelope proteins of the porcine endogenous retroviruses (PERVs

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    Denner Joachim

    2012-11-01

    Full Text Available Abstract Despite enormous difficulties to induce antibodies neutralizing HIV-1, especially broadly neutralizing antibodies directed against the conserved membrane proximal external region (MPER of the transmembrane envelope protein, such antibodies can be easily induced in the case of gammaretroviruses, among them the porcine endogenous retroviruses (PERVs. In addition to neutralizing antibodies directed against the transmembrane envelope protein p15E, neutralizing antibodies were also induced by immunization with the surface envelope protein gp70. PERVs represent a special risk for xenotransplantation using pig tissues or organs since they are integrated in the genome of all pigs and infect human cells and a vaccine may protect from transmission to the recipient. To investigate the effect of simultaneous immunization with both proteins in detail, a study was performed in hamsters. Gp70 and p15E of PERV were produced in E. coli, purified and used for immunization. All animals developed binding antibodies against the antigens used for immunization. Sera from animals immunized with p15E recognized epitopes in the MPER and the fusion peptide proximal region (FPPR of p15E. One MPER epitope showed a sequence homology to an epitope in the MPER of gp41 of HIV-1 recognized by broadly neutralizing antibodies found in HIV infected individuals. Neutralizing antibodies were detected in all sera. Most importantly, sera from animals immunized with gp70 had a higher neutralizing activity when compared with the sera from animals immunized with p15E and sera from animals immunized with gp70 together with p15E had a higher neutralizing activity compared with sera from animals immunized with each antigen alone. These immunization studies are important for the development of vaccines against other retroviruses including the human immunodeficiency virus HIV-1.

  16. Protein-Carbohydrate Interaction between Sperm and the Egg-Coating Envelope and Its Regulation by Dicalcin, a Xenopus laevis Zona Pellucida Protein-Associated Protein

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    Naofumi Miwa

    2015-05-01

    Full Text Available Protein-carbohydrate interaction regulates multiple important processes during fertilization, an essential biological event where individual gametes undergo intercellular recognition to fuse and generate a zygote. In the mammalian female reproductive tract, sperm temporarily adhere to the oviductal epithelium via the complementary interaction between carbohydrate-binding proteins on the sperm membrane and carbohydrates on the oviductal cells. After detachment from the oviductal epithelium at the appropriate time point following ovulation, sperm migrate and occasionally bind to the extracellular matrix, called the zona pellucida (ZP, which surrounds the egg, thereafter undergoing the exocytotic acrosomal reaction to penetrate the envelope and to reach the egg plasma membrane. This sperm-ZP interaction also involves the direct interaction between sperm carbohydrate-binding proteins and carbohydrates within the ZP, most of which have been conserved across divergent species from mammals to amphibians and echinoderms. This review focuses on the carbohydrate-mediated interaction of sperm with the female reproductive tract, mainly the interaction between sperm and the ZP, and introduces the fertilization-suppressive action of dicalcin, a Xenopus laevis ZP protein-associated protein. The action of dicalcin correlates significantly with a dicalcin-dependent change in the lectin-staining pattern within the ZP, suggesting a unique role of dicalcin as an inherent protein that is capable of regulating the affinity between the lectin and oligosaccharides attached on its target glycoprotein.

  17. The inner nuclear membrane protein lamin B receptor forms distinct microdomains and links epigenetically marked chromatin to the nuclear envelope.

    Science.gov (United States)

    Makatsori, Dimitra; Kourmouli, Niki; Polioudaki, Hara; Shultz, Leonard D; McLean, Kelvin; Theodoropoulos, Panayiotis A; Singh, Prim B; Georgatos, Spyros D

    2004-06-11

    Using heterochromatin-enriched fractions, we have detected specific binding of mononucleosomes to the N-terminal domain of the inner nuclear membrane protein lamin B receptor. Mass spectrometric analysis reveals that LBR-associated particles contain complex patterns of methylated/acetylated histones and are devoid of "euchromatic" epigenetic marks. LBR binds heterochromatin as a higher oligomer and forms distinct nuclear envelope microdomains in vivo. The organization of these membrane assemblies is affected significantly in heterozygous ic (ichthyosis) mutants, resulting in a variety of structural abnormalities and nuclear defects.

  18. Type B lamins remain associated with the integral nuclear envelope protein p58 during mitosis: implications for nuclear reassembly.

    Science.gov (United States)

    Meier, J; Georgatos, S D

    1994-04-15

    p58 (also referred to as the lamin B receptor) is an integral membrane protein of the nuclear envelope known to form a multimeric complex with the lamins and other nuclear proteins during interphase. To examine the fate of this complex during mitosis, we have investigated the partitioning and the molecular interactions of p58 in dividing chicken hepatoma (DU249) cells. Using confocal microscopy and double immunolabelling, we show here that lamins B1 and B2 co-localize with p58 during all phases of mitosis and co-assemble around reforming nuclei. A close juxtaposition of p58/lamin B-containing vesicles and chromosomes is already detectable in metaphase; however, p58 and lamin reassembly proceeds slowly and is completed in late telophase--G1. Flotation of mitotic membranes in sucrose density gradients and analysis of mitotic vesicles by immunoelectron microscopy confirms that p58 and most of the type B lamins reside in the same compartment. Co-immunoprecipitation of both proteins by affinity-purified anti-p58 antibodies shows that they are physically associated in the context of a mitotic p58 'sub-complex'. This sub-assembly does not include the type A lamins which are fully solubilized during mitosis. Our data provide direct, in vivo and in vitro evidence that the majority of type B lamins remain connected to nuclear membrane 'receptors' during mitosis. The implications of these findings in nuclear envelope reassembly are discussed below.

  19. Binding of human lipoproteins (low, very low, high density lipoproteins) to recombinant envelope proteins of hepatitis C virus.

    Science.gov (United States)

    Monazahian, M; Kippenberger, S; Müller, A; Seitz, H; Böhme, I; Grethe, S; Thomssen, R

    2000-06-01

    Heterogeneities in the density of hepatitis C virus (HCV)-RNA-carrying material from human sera (1.03-1.20 g/ml) are partially due to the binding of lipoproteins [low density (LDL), very low density (VLDL), high density (HDL) lipoproteins] and immunoglobulins. In this study we demonstrate the binding of recombinant HCV envelope protein (El/E2) to human LDL, VLDL and HDL on a molecular basis. The binding of lipoproteins was restricted to the middle part of the El gene product (amino acids 222-336) and the C-terminal part of the E2 protein (amino acids 523-809). Lipoproteins did not bind to recombinant HCV core protein.

  20. A flow cytometry-based screen of nuclear envelope transmembrane proteins identifies NET4/Tmem53 as involved in stress-dependent cell cycle withdrawal.

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    Nadia Korfali

    2011-04-01

    Full Text Available Disruption of cell cycle regulation is one mechanism proposed for how nuclear envelope protein mutation can cause disease. Thus far only a few nuclear envelope proteins have been tested/found to affect cell cycle progression: to identify others, 39 novel nuclear envelope transmembrane proteins were screened for their ability to alter flow cytometry cell cycle/DNA content profiles when exogenously expressed. Eight had notable effects with seven increasing and one decreasing the 4N:2N ratio. We subsequently focused on NET4/Tmem53 that lost its effects in p53(-/- cells and retinoblastoma protein-deficient cells. NET4/TMEM53 knockdown by siRNA altered flow cytometry cell cycle/DNA content profiles in a similar way as overexpression. NET4/TMEM53 knockdown did not affect total retinoblastoma protein levels, unlike nuclear envelope-associated proteins Lamin A and LAP2α. However, a decrease in phosphorylated retinoblastoma protein was observed along with a doubling of p53 levels and a 7-fold increase in p21. Consequently cells withdrew from the cell cycle, which was confirmed in MRC5 cells by a drop in the percentage of cells expressing Ki-67 antigen and an increase in the number of cells stained for ß-galactosidase. The ß-galactosidase upregulation suggests that cells become prematurely senescent. Finally, the changes in retinoblastoma protein, p53, and p21 resulting from loss of NET4/Tmem53 were dependent upon active p38 MAP kinase. The finding that roughly a fifth of nuclear envelope transmembrane proteins screened yielded alterations in flow cytometry cell cycle/DNA content profiles suggests a much greater influence of the nuclear envelope on the cell cycle than is widely held.

  1. Recombinant envelope protein of HIV-1 subtype E as antigen in HIV-1 antibody detection enzyme immunoassay.

    Science.gov (United States)

    Sutthent, Ruengpung; Kanoksinsombat, Chinda; Horthongkham, Navin; Louisirirotchanakul, Suda; Auewarakul, Prasert; Kantakamalakul, Wannee

    2002-06-01

    In order to develop a reliable and inexpensive serodiagnostic method to be used for anti-HIV antibody detection in Thailand, recombinant envelope (TM or gp41 subunit) protein of HIV-1 subtype E was produced from prokaryotic cell (Escherichia coli) as the source of antigen in enzyme immunoassay (TE diagnostic EIA kit). HIV-1 gp41 subunit of subtype E was successfully expressed in E. coli in the form of polyhistidine-tagged proteins, comprising of rgp41A (601 bases N-terminal half of TM or 25kDa) and rgp41B (560 bases C-terminal half of TM or 24 kDa) by using an expression vector, pBAD/His C. The amount of protein, dilution of sera, and anti-human IgG labeled HRP used in the EIA test optimized by a checker board titration of the protein and seropositive or seronegative sera, were 5.0 microg/ml, 1:300, and 1:4,000, respectively. The blinded test evaluation of TE-diagnostic EIA in 500 seropositive and 500 seronegative sera which have been simultaneously tested by two available commercial kits and compared with our TE diagnostic EIA, gave 99.6% sensitivity and specificity. The other known genetic subtypes sera such as subtype A (n=5), B (n=9), C (n=4) and D (n=5) were also positive with this EIA. The estimated manufacturer cost per test of rgp41 based anti-HIV antibody detection EIA or TE-diagnostic EIA was about 15 baht. This recombinant envelope (gp41 or TM) protein from HIV-1, which can be produced in large quantities without any hazards from growing the virus and has lower cost to produce anti-HIV antibody serological diagnostic kit, should be considered as an HIV screening test in Thailand.

  2. Potent in vitro antiviral activity of Cistus incanus extract against HIV and Filoviruses targets viral envelope proteins

    Science.gov (United States)

    Rebensburg, Stephanie; Helfer, Markus; Schneider, Martha; Koppensteiner, Herwig; Eberle, Josef; Schindler, Michael; Gürtler, Lutz; Brack-Werner, Ruth

    2016-01-01

    Novel therapeutic options are urgently needed to improve global treatment of virus infections. Herbal products with confirmed clinical safety features are attractive starting material for the identification of new antiviral activities. Here we demonstrate that Cistus incanus (Ci) herbal products inhibit human immunodeficiency virus (HIV) infections in vitro. Ci extract inhibited clinical HIV-1 and HIV-2 isolates, and, importantly, a virus isolate with multiple drug resistances, confirming broad anti-HIV activity. Antiviral activity was highly selective for virus particles, preventing primary attachment of the virus to the cell surface and viral envelope proteins from binding to heparin. Bioassay-guided fractionation indicated that Ci extract contains numerous antiviral compounds and therefore has favorably low propensity to induce virus resistance. Indeed, no resistant viruses emerged during 24 weeks of continuous propagation of the virus in the presence of Ci extracts. Finally, Ci extracts also inhibited infection by virus particles pseudotyped with Ebola and Marburg virus envelope proteins, indicating that antiviral activity of Ci extract extends to emerging viral pathogens. These results demonstrate that Ci extracts show potent and broad in vitro antiviral activity against viruses that cause life-threatening diseases in humans and are promising sources of agents that target virus particles. PMID:26833261

  3. Vaccinia Virus Protein F12 Associates with Intracellular Enveloped Virions through an Interaction with A36▿

    Science.gov (United States)

    Johnston, Sara C.; Ward, Brian M.

    2009-01-01

    Vaccinia virus is the prototypical member of the family Poxviridae. Three morphologically distinct forms are produced during infection: intracellular mature virions (IMV), intracellular enveloped virions (IEV), and extracellular enveloped virions (EEV). Two viral proteins, F12 and A36, are found exclusively on IEV but not on IMV and EEV. Analysis of membranes from infected cells showed that F12 was only associated with membranes and is not an integral membrane protein. A yeast two-hybrid assay revealed an interaction between amino acids 351 to 458 of F12 and amino acids 91 to 111 of A36. We generated a recombinant vaccinia virus that expresses an F12, which lacks residues 351 to 458. Characterization of this recombinant revealed a small-plaque phenotype and a subsequent defect in virus release similar to a recombinant virus that had F12L deleted. In addition, F12 lacking residues 351 to 458 was unable to associate with membranes in infected cells. These results suggest that F12 associates with IEV through an interaction with A36 and that this interaction is critical for the function of F12 during viral egress. PMID:19052096

  4. Induction of neutralizing antibodies specific for the envelope proteins of the koala retrovirus by immunization with recombinant proteins or with DNA.

    Science.gov (United States)

    Fiebig, Uwe; Dieckhoff, Britta; Wurzbacher, Christian; Möller, Annekathrin; Kurth, Reinhard; Denner, Joachim

    2015-04-30

    The koala retrovirus (KoRV) is the result of a transspecies transmission of a gammaretrovirus with fatal consequences for the new host. Like many retroviruses, KoRV induces lymphoma, leukemia and an immunodeficiency that is associated with opportunistic infections in the virus-infected animals. We recently reported the induction of neutralizing antibodies by immunization with the recombinant ectodomain of the transmembrane envelope protein p15E of KoRV. Since the neutralization titers of the p15E-specific sera were only moderate, we investigated the use of the surface envelope protein gp70 to induce neutralizing antibodies. We immunized rats and goats with the recombinant gp70 protein of the KoRV, an unglycosylated protein of 52kD (rgp70/p52) or with the corresponding DNA. In parallel we immunized with recombinant rp15E or with a combination of rp15E and rgp70/p52. In all cases binding and neutralizing antibodies were induced. The gp70-specific sera had titers of neutralizing antibodies that were 15-fold higher than the p15E-specific sera. Combining rp15E and rgp70/p52 did not significantly increase neutralizing titers compared to rgp70/p52 alone. High titers of neutralizing antibodies specific for gp70 were also induced by immunization with DNA. Since KoRV and PERV are closely related, we investigated cross-neutralization of the antisera. The antisera against p15E and gp70 of PERV and KoRV inhibited infection by both viruses. The envelope proteins of the KoRV may therefore form the basis of an effective preventive vaccine to protect uninfected koalas from infection and possibly an immunotherapeutic treatment for those already infected.

  5. Expression of large hepatitis B envelope protein mutants using a new expression vector.

    Science.gov (United States)

    Korec, E; Gerlich, W H

    1992-01-01

    Aminoterminal deletion mutants of the gene encoding the large hepatitis B surface protein were expressed in COS cells using a new expression vector. The truncated protein showed the same intracellular retention like the wild type protein. The findings show that the secretion block of the protein is not due to its aminoterminal myristylation.

  6. Expression of particulate-form of Japanese encephalitis virus envelope protein in a stably transfected Drosophila cell line

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    Zhang Li

    2007-02-01

    Full Text Available Abstract Background Japanese encephalitis virus (JEV, a member of the family Flaviviridae, is an important mosquito-borne human pathogen. Its envelope glycoprotein (E is the major determinant of the pathogenicity and host immune responses. In the present study, we explored the feasibility of producing recombinant JEV E protein in the virus-free Drosophila expression system. Results The coding sequence for the signal sequence of premembrane and E protein was cloned into the Drosophila expression vector pAc5.1/V5-His. A Drosophila cell line S2 was cotransfected with this construct as well as a plasmid providing hygromycin B resistance. A cell line expressing the JEV E protein was selected by immunofluoresence, confocal microscopy, and western blot analysis using three different monoclonal antibodies directed against JEV E protein. This cell line was stable in the yield of JEV E protein during two months in vitro maintenance in the presence of hygromycin B. The results showed that the recombinant E protein had an expected molecular weight of about 50 kilodalton, was immunoreactive with all three monoclonal antibodies, and found in both the cytoplasm and culture supernatant. Sucrose gradient ultracentrifugation analysis revealed that the secreted E protein product was in a particulate form. It migrated to the sucrose fraction with a density of 1.13 g/ml. Balb/c mice immunised with the sucrose fraction containing the E protein particles developed specific antibodies. These data show that functioning JEV E protein was expressed in the stable S2 cell line. Conclusion The Drosophila expression system is a more convenient, cheaper and safer approach to the production of vaccine candidates and diagnostic reagents for JEV.

  7. FULL-LENGTH PEPTIDE ASSAY OF ANTIGENIC PROFILE OF ENVELOPE PROTEINS FROM SIBERIAN ISOLATES OF HEPATITIS C VIRUS

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    A. A. Grazhdantseva

    2010-01-01

    Full Text Available Antigenic profiles of envelope glycoproteins of hepatitis C virus presented by three genotypes 1b, 2a/2c and 3a, which are most widespread in the territory of Russia and, in particular, in Novosibirsk, were studied using a panel of overlapping synthetic peptides. It was shown that highly immunogenic peptide epitopes of Е1 and Е2 proteins common for all HCV genotypes, are located in amino acid positions 250-260, 315-325 (Е1 protein, 390-400 (hypervariable region 1, 430-440, and 680-690 (Е2 protein. The greatest inter-genotypic differences were recorded in positions 280-290, 410-430 and 520-540. A novel antigenic determinant was detected in the region of aa 280-290 of the Е1 protein which was typical only for HCV 2a/2c genotype. A broad variation in the boundaries for the most epitopes suggests a high variability of the Е1 and Е2 viral proteins; however, a similar repertoire of antibodies induced by different HCV genotypes indicates to an opportunity of designing a new generation of cross-reactive HCV vaccines based on mapping of the E1 and E2 antigenic regions.

  8. Oral immunization of mice with Japanese encephalitis virus envelope protein synthesized in Escherichia coli induces anti-viral antibodies.

    Science.gov (United States)

    Rauthan, Manish; Kaur, Rupinderjeet; Appaiahgari, Mohan Babu; Vrati, Sudhanshu

    2004-11-01

    In order to evaluate the possibility of developing an oral vaccine against Japanese encephalitis virus (JEV), mice were fed with recombinant JEV envelope (E) protein synthesized in Escherichia coli. The protein was administered orally to mice with or without an immunostimulatory cytosine-phosphate-guanosine (CpG) motif containing synthetic oligodeoxynucleotide (ODN) as an adjuvant. The immunized mice made high-titered anti-E and anti-JEV antibodies. Mice immunized with JEV E protein along with the ODN adjuvant produced higher antibody titers and these were predominantly IgG2a type. These antibodies, however, failed to neutralize JEV activity in vitro, and the immunization did not protect the mice against lethal JEV challenge. Splenocytes from the immunized mice secreted large amounts of interferon (IFN)-gamma and showed proliferation in the presence of JEV E protein. Our results indicate that JEV E protein delivered orally to mice together with ODN generated both humoral and cellular immune responses to JEV, and these were of the Th1 type.

  9. Antigenicity of envelop and non-structural proteins of dengue serotypes and their potentiality to elicit specifi antibody

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    Ramesh Venkatachalam

    2015-06-01

    Full Text Available Objective: To find out the antigenic nature of envelop (E and non-structural (NS proteins and their ability to induce specific antibodies, and to investigate specific antibody produced by specific dengue virus (DENV serotypes. Methods: Amino acid sequences of E and NS proteins of dengue serotypes were analysed by using VaxiJen antigen predicition server. The transmembrane of topology analyses were conducted by using transmembrane prediction using hidden markov models. The Hex dock server was used for docking. Results: The antigenicity score and exomembrane potentiality of E and NS proteins were calculated. All those proteins were antigenic; these antigens were made to interact with antibodies such as immunoglobulin A, immunoglobulin G and immunoglobulin M. Higher energy values of immunoglobulin M were found in DENV-1 and DENV-2, and more energy values were found in immunoglobulin G of DENV-3, DENV-4, NS-1, NS-3 and NS-5. Conclusions: In the present study, DENV-1 and DENV-2 are positive to immunoglobulin M and involved in the primary infection. DENV 3, DENV 4 and all the NS proteins (NS-1, NS-3, NS-5 which elicit immunoglobulin G are involved in the secondary infection.

  10. Unusual Reversible Oligomerization of Unfolded Dengue Envelope Protein Domain 3 at High Temperatures and Its Abolition by a Point Mutation.

    Science.gov (United States)

    Saotome, Tomonori; Nakamura, Shigeyoshi; Islam, Mohammad M; Nakazawa, Akiko; Dellarole, Mariano; Arisaka, Fumio; Kidokoro, Shun-Ichi; Kuroda, Yutaka

    2016-08-16

    We report differential scanning calorimetry (DSC) experiments between 10 and 120 °C of Dengue 4 envelope protein domain 3 (DEN4 ED3), a small 107-residue monomeric globular protein domain. The thermal unfolding of DEN4 ED3 was fully reversible and exhibited two peculiar endothermic peaks. AUC (analytical ultracentrifugation) experiments at 25 °C indicated that DEN4 ED3 was monomeric. Detailed thermodynamic analysis indicated that the two endothermic peaks separated with an increasing protein concentration, and global fitting of the DSC curves strongly suggested the presence of unfolded tetramers at temperatures around 80-90 °C, which dissociated to unfolded monomers at even higher temperatures. To further characterize this rare thermal unfolding process, we designed and constructed a DEN4 ED3 variant that would unfold according to a two-state model, typical of globular proteins. We thus substituted Val 380, the most buried residue at the dimeric interface in the protein crystal, with less hydrophobic amino acids (Ala, Ser, Thr, Asn, and Lys). All variants showed a single heat absorption peak, typical of small globular proteins. In particular, the DSC thermogram of DEN4 V380K indicated a two-state reversible thermal unfolding independent of protein concentration, indicating that the high-temperature oligomeric state was successfully abolished by a single mutation. These observations confirmed the standard view that small monomeric globular proteins undergo a two-state unfolding. However, the reversible formation of unfolded oligomers at high temperatures is a truly new phenomenon, which was fully inhibited by an accurately designed single mutation.

  11. Identification of peptides that bind hepatitis C virus envelope protein E2 and inhibit viral cellular entry from a phage-display peptide library.

    Science.gov (United States)

    Lü, Xin; Yao, Min; Zhang, Jian-Min; Yang, Jing; Lei, Ying-Feng; Huang, Xiao-Jun; Jia, Zhan-Sheng; Ma, Li; Lan, Hai-Yun; Xu, Zhi-Kai; Yin, Wen

    2014-05-01

    Hepatitis C virus (HCV) envelope protein E2 is required for the entry of HCV into cells. Viral envelope proteins interact with cell receptors in a multistep process, which may be a promising target for the development of novel antiviral agents. In this study, a heptapeptide M13 phage-display library was screened for peptides that bind specifically to prokaryotically expressed, purified truncated HCV envelope protein E2. ELISA assay was used to quantify the binding of the peptides to HCV E2 protein. Flow cytometry, quantitative reverse-transcription PCR and western blotting were used to investigate the inhibition effect of one peptide on HCV infection in hepatoma cells (Huh7.5) in vitro. Four peptides capable of binding specifically to HCV E2 protein were obtained after three rounds of biopanning. Peptide C18 (WPWHNHR), with the highest affinity for binding HCV E2 protein, was synthesized. The results showed that peptide C18 inhibited the viral infectivity of both HCV pseudotype particles (HCVpp) harboring HCV envelope glycoproteins and cell-culture produced HCV (HCVcc). Thus, this study demonstrated that peptide C18 is a potential candidate for anti-HCV therapy as a novel viral entry inhibitor.

  12. Characterization of the ectodomain of the envelope protein of dengue virus type 4: expression, membrane association, secretion and particle formation in the absence of precursor membrane protein.

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    Szu-Chia Hsieh

    Full Text Available The envelope (E of dengue virus (DENV is the major target of neutralizing antibodies and vaccine development. After biosynthesis E protein forms a heterodimer with precursor membrane (prM protein. Recent reports of infection enhancement by anti-prM monoclonal antibodies (mAbs suggest anti-prM responses could be potentially harmful. Previously, we studied a series of C-terminal truncation constructs expressing DENV type 4 prM/E or E proteins and found the ectodomain of E protein alone could be recognized by all 12 mAbs tested, suggesting E protein ectodomain as a potential subunit immunogen without inducing anti-prM response. The characteristics of DENV E protein ectodomain in the absence of prM protein remains largely unknown.In this study, we investigated the expression, membrane association, glycosylation pattern, secretion and particle formation of E protein ectodomain of DENV4 in the presence or absence of prM protein. E protein ectodomain associated with membrane in or beyond trans-Golgi and contained primarily complex glycans, whereas full-length E protein associated with ER membrane and contained high mannose glycans. In the absence of prM protein, E protein ectodomain can secrete as well as form particles of approximately 49 nm in diameter, as revealed by sucrose gradient ultracentrifugation with or without detergent and electron microscopy. Mutational analysis revealed that the secretion of E protein ectodomain was affected by N-linked glycosylation and could be restored by treatment with ammonia chloride.Considering the enhancement of DENV infectivity by anti-prM antibodies, our findings provide new insights into the expression and secretion of E protein ectodomain in the absence of prM protein and contribute to future subunit vaccine design.

  13. Human endogenous retrovirus-FRD envelope protein (syncytin 2 expression in normal and trisomy 21-affected placenta

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    Handschuh Karen

    2008-01-01

    Full Text Available Abstract Human trophoblast expresses two fusogenic retroviral envelope proteins, the widely studied syncytin 1, encoded by HERV-W and the recently characterized syncytin 2 encoded by HERV-FRD. Here we studied syncytin 2 in normal and Trisomy 21-affected placenta associated with abnormal trophoblast differentiation. Syncytin 2 immunolocalization was restricted throughout normal pregnancy to some villous cytotrophoblastic cells (CT. During the second trimester of pregnancy, syncytin 2 was immunolocalized in some cuboidal CT in T21 placentas, whereas in normal placentas it was observed in flat CT, extending into their cytoplasmic processes. In vitro, CT isolated from normal placenta fuse and differentiate into syncytiotrophoblast. At the same time, syncytin 2 transcript levels decreased significantly with syncytiotrophoblast formation. In contrast, CT isolated from T21-affected placentas fused and differentiated poorly and no variation in syncytin 2 transcript levels was observed. Syncytin 2 expression illustrates the abnormal trophoblast differentiation observed in placenta of fetal T21-affected pregnancies.

  14. Chromosomal assignment of human nuclear envelope protein genes LMNA, LMNB1, and LBR by fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Wydner, K.L.; McNeil, J.A. [Univ. of Masssachusetts Medical Center, Worcester, MA (United States); Lin, Feng [Columbia Univ., New York, NY (United States)] [and others

    1996-03-05

    We have used fluorescence in situ hybridization to establish precise chromosomal localizations for three human genes encoding four different nuclear envelope proteins. Lamin A/C (LMN1, HGMW-approved symbol LMNA) mapped to 1q21.2-q21.3, with a most probable gene assignment to 1q21.3; lamin B receptor (LBR) was localized to 1q42.1; and lamin B1 (LMNB1) was mapped to the interface of bands 5q23.3-q31.1. Assignments were determined by direct placement of signals relative to high-resolution DAPI or G-bands. Comparison of these results of band positions predicted from fractional length measurements to signal placement indicated that more accurate predictions are made using Francke idiograms and that measurement strategy avoids variance due to polymorphic chromosome segments. 30 refs., 2 figs., 1 tab.

  15. Building envelope

    CSIR Research Space (South Africa)

    Gibberd, Jeremy T

    2009-01-01

    Full Text Available This chapter describes the way building envelopes can contribute to developing green buildings and sets out some objectives that could be aimed for. It also proposes a number of approaches that can be used to help design green building envelopes...

  16. Membrane and envelope virus proteins co-expressed as lysosome associated membrane protein (LAMP fused antigens: a potential tool to develop DNA vaccines against flaviviruses

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    Rafael Dhalia

    2009-12-01

    Full Text Available Vaccination is the most practical and cost-effective strategy to prevent the majority of the flavivirus infection to which there is an available vaccine. However, vaccines based on attenuated virus can potentially promote collateral side effects and even rare fatal reactions. Given this scenario, the developent of alternative vaccination strategies such as DNA-based vaccines encoding specific flavivirus sequences are being considered. Endogenous cytoplasmic antigens, characteristically plasmid DNA-vaccine encoded, are mainly presented to the immune system through Major Histocompatibility Complex class I - MHC I molecules. The MHC I presentation via is mostly associated with a cellular cytotoxic response and often do not elicit a satisfactory humoral response. One of the main strategies to target DNA-encoded antigens to the MHC II compartment is expressing the antigen within the Lysosome-Associated Membrane Protein (LAMP. The flavivirus envelope protein is recognized as the major virus surface protein and the main target for neutralizing antibodies. Different groups have demonstrated that co-expression of flavivirus membrane and envelope proteins in mammalian cells, fused with the carboxyl-terminal of LAMP, is able to induce satisfactory levels of neutralizing antibodies. Here we reviewed the use of the envelope flavivirus protein co-expression strategy as LAMP chimeras with the aim of developing DNA vaccines for dengue, West Nile and yellow fever viruses.A vacinação é a estratégia mais prática e o melhor custo-benefício para prevenir a maioria das infecções dos flavivirus, para os quais existe vacina disponível. Entretanto, as vacinas baseadas em vírus atenuados podem potencialmente promover efeitos colaterais e, mais raramente, reações fatais. Diante deste cenário, o desenvolvimento de estratégias alternativas de vacinação, como vacinas baseadas em DNA codificando seqüências específicas dos flavivirus, está sendo considerado

  17. The kinase inhibitor SFV785 dislocates dengue virus envelope protein from the replication complex and blocks virus assembly.

    Directory of Open Access Journals (Sweden)

    Azlinda Anwar

    Full Text Available Dengue virus (DENV is the etiologic agent for dengue fever, for which there is no approved vaccine or specific anti-viral drug. As a remedy for this, we explored the use of compounds that interfere with the action of required host factors and describe here the characterization of a kinase inhibitor (SFV785, which has selective effects on NTRK1 and MAPKAPK5 kinase activity, and anti-viral activity on Hepatitis C, DENV and yellow fever viruses. SFV785 inhibited DENV propagation without inhibiting DENV RNA synthesis or translation. The compound did not cause any changes in the cellular distribution of non-structural 3, a protein critical for DENV RNA synthesis, but altered the distribution of the structural envelope protein from a reticulate network to enlarged discrete vesicles, which altered the co-localization with the DENV replication complex. Ultrastructural electron microscopy analyses of DENV-infected SFV785-treated cells showed the presence of viral particles that were distinctly different from viable enveloped virions within enlarged ER cisternae. These viral particles were devoid of the dense nucleocapsid. The secretion of the viral particles was not inhibited by SFV785, however a reduction in the amount of secreted infectious virions, DENV RNA and capsid were observed. Collectively, these observations suggest that SFV785 inhibited the recruitment and assembly of the nucleocapsid in specific ER compartments during the DENV assembly process and hence the production of infectious DENV. SFV785 and derivative compounds could be useful biochemical probes to explore the DENV lifecycle and could also represent a new class of anti-virals.

  18. Immunogenicity and protective efficacy of recombinant major envelope protein (rH3L) of buffalopox virus in animal models.

    Science.gov (United States)

    Kumar, Amit; Yogisharadhya, Revanaiah; Venkatesan, Gnanavel; Bhanuprakash, Veerakyathappa; Shivachandra, Sathish Bhadravati

    2016-02-01

    Buffalopox virus, a zoonotic Indian vaccinia-like virus, is responsible for contagious disease affecting mainly buffaloes, cattle and humans. H3L gene, encoding for an immunodominant major envelope protein of intracellular mature virion of orthopoxviruses, is highly conserved and found to elicit neutralizing antibodies. Therefore in the present study, the immunogenicity and protective efficacy of the recombinant H3L protein of buffalopox virus in laboratory animal models has been evaluated. A partial H3L gene encoding for the C-terminal truncated ectodomain of H3L protein (1M to I280) of BPXV-Vij/96 strain was cloned, over-expressed and purified as histidine-tagged fusion protein (50 kDa) from Escherichia coli using Ni-NTA affinity chromatography. The purified rH3L protein was further used for active immunization of guinea pig (250 μg/dose) and adult mice (10 μg and 50 μg/dose) with or without adjuvants (alum, Freund's Complete Adjuvant and CpG). Subsequently, a gradual increase in antigen specific serum IgG as well as neutralizing antibody titres measured by using indirect-ELISA and serum neutralization test respectively, was noted in both guinea pigs and mouse models. Suckling mice immunized passively with anti-H3L serum showed 80% pre-exposure prophylaxis upon challenge with virulent buffalopox virus strain. An indirect-ELISA based on rH3L protein showed no cross-reactivity with hyperimmune sera against sheeppox virus (SPPV), goatpox virus (GTPV), orf virus (ORFV), foot- and- mouth disease virus (FMDV), peste des petits ruminants virus (PPRV) and bluetongue virus (BTV) during the course of study. The study highlights the potential utility of rH3L protein as a safer prophylactic and diagnostic reagent for buffalopox. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Enhanced immunogenicity of HIV-1 envelope gp140 proteins fused to APRIL.

    Science.gov (United States)

    Isik, Gözde; Sliepen, Kwinten; van Montfort, Thijs; Sanders, Rogier W

    2014-01-01

    Current HIV-1 vaccines based on the HIV-1 envelope glycoprotein spike (Env), the only relevant target for broadly neutralizing antibodies, are unable to induce protective immunity. Env immunogenicity can be enhanced by fusion to costimulatory molecules involved in B cell activation, such as APRIL and CD40L. Here, we found that Env-APRIL signaled through the two receptors, BCMA and TACI. In rabbits, Env-APRIL induced significantly higher antibody responses against Env compared to unconjugated Env, while the antibody responses against the APRIL component were negligible. To extend this finding, we tested Env-APRIL in mice and found minimal antibody responses against APRIL. Furthermore, Env-CD40L did not induce significant anti-CD40L responses. Thus, in contrast to the 4-helix cytokines IL-21 and GM-CSF, the TNF-superfamily members CD40L and APRIL induced negligible autoantibodies. This study confirms and extends previous work and shows that fusion of Env-based immunogens to APRIL can improve Env immunogenicity and might help in designing HIV vaccines that induce protective humoral immunity.

  20. Enhanced immunogenicity of HIV-1 envelope gp140 proteins fused to APRIL.

    Directory of Open Access Journals (Sweden)

    Gözde Isik

    Full Text Available Current HIV-1 vaccines based on the HIV-1 envelope glycoprotein spike (Env, the only relevant target for broadly neutralizing antibodies, are unable to induce protective immunity. Env immunogenicity can be enhanced by fusion to costimulatory molecules involved in B cell activation, such as APRIL and CD40L. Here, we found that Env-APRIL signaled through the two receptors, BCMA and TACI. In rabbits, Env-APRIL induced significantly higher antibody responses against Env compared to unconjugated Env, while the antibody responses against the APRIL component were negligible. To extend this finding, we tested Env-APRIL in mice and found minimal antibody responses against APRIL. Furthermore, Env-CD40L did not induce significant anti-CD40L responses. Thus, in contrast to the 4-helix cytokines IL-21 and GM-CSF, the TNF-superfamily members CD40L and APRIL induced negligible autoantibodies. This study confirms and extends previous work and shows that fusion of Env-based immunogens to APRIL can improve Env immunogenicity and might help in designing HIV vaccines that induce protective humoral immunity.

  1. A laminin-receptor-like protein regulates white spot syndrome virus infection by binding to the viral envelope protein VP28 in red claw crayfish Cherax quadricarinatus.

    Science.gov (United States)

    Liu, Ling-Ke; Li, Wei-Dong; Gao, Yan; Chen, Rong-Yuan; Xie, Xiao-Lu; Hong, Heng; Wang, Ke-Jian; Liu, Hai-Peng

    2018-02-01

    White spot syndrome virus (WSSV) is a lethal pathogen of shrimp and many other crustaceans, which has been causing huge economic losses in global aquaculture. Laminin receptor (LR) is a cell surface receptor which participates in the interactions between cells as well as cells and extracellular matrix. Previously, we found that a CqLR-like gene was responsive to WSSV infection in the hematopoietic tissue (Hpt) cells from red claw crayfish Cherax quadricarinatus. To further reveal the role of CqLR-like gene involved in WSSV infection, the full-length cDNA of CqLR-like gene was cloned with 1000 bp, and the open reading frame encoded 308 amino acids with a conserved laminin-binding domain. Importantly, both the WSSV entry and viral replication were strongly reduced in Hpt cells after loss-of-function of CqLR-like gene by gene silencing. Protein interaction assay demonstrated that the recombinant CqLR-like protein could bind to WSSV virion in vitro by enzyme-linked immunosorbent assay and the binding affinity was in a dose-dependent manner. Furthermore, recombinant CqLR-like protein was found to bind to WSSV envelop protein VP28, but not other envelop proteins tested including VP19, VP24, and VP26, by pull down assay in HEK293T cells. In regarding to that LR is mainly localized on many types of cells' membrane, these data together suggested that CqLR-like protein was likely to function as a putative recognition molecule towards WSSV and act in the viral entry into a crustacean host cell, which may benefit the elucidation of the WSSV pathogenesis and further the pharmaceutical target for the possibly effective control of WSSV disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. GB Virus Type C Envelope Protein E2 Elicits Antibodies That React with a Cellular Antigen on HIV-1 Particles and Neutralize Diverse HIV-1 Isolates

    Science.gov (United States)

    Mohr, Emma L.; Xiang, Jinhua; McLinden, James H.; Kaufman, Thomas M.; Chang, Qing; Montefiori, David C.; Klinzman, Donna; Stapleton, Jack T.

    2012-01-01

    Broadly neutralizing Abs to HIV-1 are well described; however, identification of Ags that elicit these Abs has proven difficult. Persistent infection with GB virus type C (GBV-C) is associated with prolonged survival in HIV-1–infected individuals, and among those without HIV-1 viremia, the presence of Ab to GBV-C glycoprotein E2 is also associated with survival. GBV-C E2 protein inhibits HIV-1 entry, and an antigenic peptide within E2 interferes with gp41-induced membrane perturbations in vitro, suggesting the possibility of structural mimicry between GBV-C E2 protein and HIV-1 particles. Naturally occurring human and experimentally induced GBV-C E2 Abs were examined for their ability to neutralize infectious HIV-1 particles and HIV-1–enveloped pseudovirus particles. All GBV-C E2 Abs neutralized diverse isolates of HIV-1 with the exception of rabbit anti-peptide Abs raised against a synthetic GBV-C E2 peptide. Rabbit anti–GBV-C E2 Abs neutralized HIV-1–pseudotyped retrovirus particles but not HIV-1–pseudotyped vesicular stomatitis virus particles, and E2 Abs immune-precipitated HIV-1 gag particles containing the vesicular stomatitis virus type G envelope, HIV-1 envelope, GBV-C envelope, or no viral envelope. The Abs did not neutralize or immune-precipitate mumps or yellow fever viruses. Rabbit GBV-C E2 Abs inhibited HIV attachment to cells but did not inhibit entry following attachment. Taken together, these data indicate that the GBV-C E2 protein has a structural motif that elicits Abs that cross-react with a cellular Ag present on retrovirus particles, independent of HIV-1 envelope glycoproteins. The data provide evidence that a heterologous viral protein can induce HIV-1–neutralizing Abs. PMID:20826757

  3. The type 2 dengue virus envelope protein interacts with small ubiquitin-like modifier-1 (SUMO-1) conjugating enzyme 9 (Ubc9).

    Science.gov (United States)

    Chiu, Mei-Wui; Shih, Hsiu-Ming; Yang, Tsung-Han; Yang, Yun-Liang

    2007-05-01

    Dengue viruses are mosquito-borne flaviviruses and may cause the life-threatening dengue hemorrhagic fever and dengue shock syndrome. Its envelope protein is responsible mainly for the virus attachment and entry to host cells. To identify the human cellular proteins interacting with the envelope protein of dengue virus serotype 2 inside host cells, we have performed a screening with the yeast-two-hybrid-based "Functional Yeast Array". Interestingly, the small ubiquitin-like modifier-1 conjugating enzyme 9 protein, modulating cellular processes such as those regulating signal transduction and cell growth, was one of the candidates interacting with the dengue virus envelope protein. With co-precipitation assay, we have demonstrated that it indeed could interact directly with the Ubc9 protein. Site-directed mutagenesis has demonstrated that Ubc9 might interact with the E protein via amino acid residues K51 and K241. Furthermore, immunofluorescence microscopy has shown that the DV2E-EGFP proteins tended to progress toward the nuclear membrane and co-localized with Flag-Ubc9 proteins around the nuclear membrane in the cytoplasmic side, and DV2E-EGFP also shifted the distribution of Flag-Ubc9 from evenly in the nucleus toward concentrating around the nuclear membrane in the nucleic side. In addition, over-expression of Ubc9 could reduce the plaque formation of the dengue virus in mammalian cells. This is the first report that DV envelope proteins can interact with the protein of sumoylation system and Ubc9 may involve in the host defense system to prevent virus propagation.

  4. Specific detection of dengue and Zika virus antibodies using envelope proteins with mutations in the conserved fusion loop.

    Science.gov (United States)

    Rockstroh, Alexandra; Moges, Beyene; Barzon, Luisa; Sinigaglia, Alessandro; Palù, Giorgio; Kumbukgolla, Widuranga; Schmidt-Chanasit, Jonas; Sarno, Manoel; Brites, Carlos; Moreira-Soto, Andres; Drexler, Jan Felix; Ferreira, Orlando C; Ulbert, Sebastian

    2017-11-08

    Detection of antibodies is widely used for the diagnosis of infections with arthropod-borne flaviviruses including dengue (DENV) and Zika virus (ZIKV). Due to the emergence of ZIKV in areas endemic for DENV, massive co-circulation is observed and methods to specifically diagnose these infections and differentiate them from each other are mandatory. However, serological assays for flaviviruses in general, and for DENV and ZIKV in particular, are compromised by the high degree of similarities in their proteins which can lead to cross-reacting antibodies and false-positive test results. Cross-reacting flavivirus antibodies mainly target the highly conserved fusion loop (FL) domain in the viral envelope (E-) protein, and we and others have shown previously that recombinant E-proteins bearing FL-mutations strongly reduce cross-reactivity. Here we investigate whether such mutant E-proteins can be used to specifically detect antibodies against DENV and ZIKV in an ELISA-format. IgM antibodies against DENV and ZIKV virus were detected with 100% and 94.2% specificity and 90.7% and 87.5% sensitivity, respectively. For IgG the mutant E-proteins showed cross-reactivity, which was overcome by pre-incubation of the sera with the heterologous antigen. This resulted in specificities of 97.1% and 97.9% and in sensitivities of 100% and 100% for the DENV and ZIKV antigens, respectively. Our results suggest that E-proteins bearing mutations in the FL-domain have a high potential for the development of serological DENV and ZIKV tests with high specificity.

  5. SARS-CoV envelope protein palmitoylation or nucleocapid association is not required for promoting virus-like particle production.

    Science.gov (United States)

    Tseng, Ying-Tzu; Wang, Shiu-Mei; Huang, Kuo-Jung; Wang, Chin-Tien

    2014-04-27

    Coronavirus membrane (M) proteins are capable of interacting with nucleocapsid (N) and envelope (E) proteins. Severe acute respiratory syndrome coronavirus (SARS-CoV) M co-expression with either N or E is sufficient for producing virus-like particles (VLPs), although at a lower level compared to M, N and E co-expression. Whether E can release from cells or E/N interaction exists so as to contribute to enhanced VLP production is unknown. It also remains to be determined whether E palmitoylation or disulfide bond formation plays a role in SARS-CoV virus assembly. SARS-CoV N is released from cells through an association with E protein-containing vesicles. Further analysis suggests that domains involved in E/N interaction are largely located in both carboxyl-terminal regions. Changing all three E cysteine residues to alanines did not exert negative effects on E release, E association with N, or E enhancement of VLP production, suggesting that E palmitoylation modification or disulfide bond formation is not required for SARS-CoV virus assembly. We found that removal of the last E carboxyl-terminal residue markedly affected E release, N association, and VLP incorporation, but did not significantly compromise the contribution of E to efficient VLP production. The independence of the SARS-CoV E enhancement effect on VLP production from its viral packaging capacity suggests a distinct SARS-CoV E role in virus assembly.

  6. Targeting and assembly of components of the TOC protein import complex at the chloroplast outer envelope membrane.

    Science.gov (United States)

    Richardson, Lynn G L; Paila, Yamuna D; Siman, Steven R; Chen, Yi; Smith, Matthew D; Schnell, Danny J

    2014-01-01

    The translocon at the outer envelope membrane of chloroplasts (TOC) initiates the import of thousands of nuclear encoded preproteins required for chloroplast biogenesis and function. The multimeric TOC complex contains two GTP-regulated receptors, Toc34 and Toc159, which recognize the transit peptides of preproteins and initiate protein import through a β-barrel membrane channel, Toc75. Different isoforms of Toc34 and Toc159 assemble with Toc75 to form structurally and functionally diverse translocons, and the composition and levels of TOC translocons is required for the import of specific subsets of coordinately expressed proteins during plant growth and development. Consequently, the proper assembly of the TOC complexes is key to ensuring organelle homeostasis. This review will focus on our current knowledge of the targeting and assembly of TOC components to form functional translocons at the outer membrane. Our analyses reveal that the targeting of TOC components involves elements common to the targeting of other outer membrane proteins, but also include unique features that appear to have evolved to specifically facilitate assembly of the import apparatus.

  7. Targeting and Assembly of Components of the TOC Protein Import Complex at the Chloroplast Outer Envelope Membrane

    Directory of Open Access Journals (Sweden)

    Lynn G.L. Richardson

    2014-06-01

    Full Text Available The translocon at the outer envelope membrane of chloroplasts (TOC initiates the import of thousands of nuclear encoded preproteins required for chloroplast biogenesis and function. The multimeric TOC complex contains two GTP-regulated receptors, Toc34 and Toc159, which recognize the transit peptides of preproteins and initiate protein import through a β–barrel membrane channel, Toc75. Different isoforms of Toc34 and Toc159 assemble with Toc75 to form structurally and functionally diverse translocons, and the composition and levels of TOC translocons is required for the import of specific subsets of coordinately expressed proteins during plant growth and development. Consequently, the proper assembly of the TOC complexes is key to ensuring organelle homeostasis. This review will focus on our current knowledge of the targeting and assembly of TOC components to form functional translocons at the outer membrane. Our analyses reveal that the targeting of TOC components involves elements common to the targeting of other outer membrane proteins, but also include unique features that appear to have evolved to specifically facilitate assembly of the import apparatus.

  8. Immunization of Zika virus envelope protein domain III induces specific and neutralizing immune responses against Zika virus.

    Science.gov (United States)

    Yang, Ming; Dent, Matthew; Lai, Huafang; Sun, Haiyan; Chen, Qiang

    2017-07-24

    In this study, we described the generation and immunogenicity of the Zika Virus (ZIKV) envelope protein (E) domain III (DIII) as a protein subunit vaccine candidate. ZIKV EDIII (zEDIII) was rapidly produced in E. coli in inclusion bodies. ZIKV EDIII was solubilized, refolded and purified to >95% homogeneity with a one-step Ni2+ affinity chromatography process. Further analysis revealed that zEDIII was refolded properly and demonstrated specific binding to an anti-zEDIII monoclonal antibody that recognizes a zEDIII conformational epitope. Subcutaneous immunization of mice with 25 and 50μg of zEDIII was performed over a period of 11weeks. zEDIII evoked ZIKV-specific and neutralizing antibody response with titers that exceed the threshold that correlates with protective immunity against ZIKV. The antigen-specific IgG isotypes were predominantly IgG1 and splenocyte cultures from immunized mice secreted IFN-gamma, IL-4 and IL-6. Notably, zEDIII-elicited antibodies did not enhance the infection of dengue virus in Fc gamma receptor (FcγR)-expressing cells. This study provided a proof of principle for the further development of recombinant protein-based subunit vaccines against ZIKV. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. HEMO, an ancestral endogenous retroviral envelope protein shed in the blood of pregnant women and expressed in pluripotent stem cells and tumors.

    Science.gov (United States)

    Heidmann, Odile; Béguin, Anthony; Paternina, Janio; Berthier, Raphaël; Deloger, Marc; Bawa, Olivia; Heidmann, Thierry

    2017-08-08

    Capture of retroviral envelope genes is likely to have played a role in the emergence of placental mammals, with evidence for multiple, reiterated, and independent capture events occurring in mammals, and be responsible for the diversity of present day placental structures. Here, we uncover a full-length endogenous retrovirus envelope protein, dubbed HEMO [human endogenous MER34 (medium-reiteration-frequency-family-34) ORF], with unprecedented characteristics, because it is actively shed in the blood circulation in humans via specific cleavage of the precursor envelope protein upstream of the transmembrane domain. At variance with previously identified retroviral envelope genes, its encoding gene is found to be transcribed from a unique CpG-rich promoter not related to a retroviral LTR, with sites of expression including the placenta as well as other tissues and rather unexpectedly, stem cells as well as reprogrammed induced pluripotent stem cells (iPSCs), where the protein can also be detected. We provide evidence that the associated retroviral capture event most probably occurred >100 Mya before the split of Laurasiatheria and Euarchontoglires, with the identified retroviral envelope gene encoding a full-length protein in all simians under purifying selection and with similar shedding capacity. Finally, a comprehensive screen of the expression of the gene discloses high transcript levels in several tumor tissues, such as germ cell, breast, and ovarian tumors, with in the latter case, evidence for a histotype dependence and specific protein expression in clear-cell carcinoma. Altogether, the identified protein could constitute a "stemness marker" of the normal cell and a possible target for immunotherapeutic approaches in tumors.

  10. Production of dengue virus envelope protein domain III-based antigens in tobacco chloroplasts using inducible and constitutive expression systems.

    Science.gov (United States)

    Gottschamel, Johanna; Lössl, Andreas; Ruf, Stephanie; Wang, Yanliang; Skaugen, Morten; Bock, Ralph; Clarke, Jihong Liu

    2016-07-01

    Dengue fever is a disease in many parts of the tropics and subtropics and about half the world's population is at risk of infection according to the World Health Organization. Dengue is caused by any of the four related dengue virus serotypes DEN-1, -2, -3 and -4, which are transmitted to people by Aedes aegypti mosquitoes. Currently there is only one vaccine (Dengvaxia(®)) available (limited to a few countries) on the market since 2015 after half a century's intensive efforts. Affordable and accessible vaccines against dengue are hence still urgently needed. The dengue envelop protein domain III (EDIII), which is capable of eliciting serotype-specific neutralizing antibodies, has become the focus for subunit vaccine development. To contribute to the development of an accessible and affordable dengue vaccine, in the current study we have used plant-based vaccine production systems to generate a dengue subunit vaccine candidate in tobacco. Chloroplast genome engineering was applied to express serotype-specific recombinant EDIII proteins in tobacco chloroplasts using both constitutive and ethanol-inducible expression systems. Expression of a tetravalent antigen fusion construct combining EDIII polypeptides from all four serotypes was also attempted. Transplastomic EDIII-expressing tobacco lines were obtained and homoplasmy was verified by Southern blot analysis. Northern blot analyses showed expression of EDIII antigen-encoding genes. EDIII protein accumulation levels varied for the different recombinant EDIII proteins and the different expression systems, and reached between 0.8 and 1.6 % of total cellular protein. Our study demonstrates the suitability of the chloroplast compartment as a production site for an EDIII-based vaccine candidate against dengue fever and presents a Gateway(®) plastid transformation vector for inducible transgene expression.

  11. DNA prime/protein boost vaccination elicits robust humoral response in rhesus macaques using oligomeric simian immunodeficiency virus envelope and Advax delta inulin adjuvant.

    Science.gov (United States)

    Menon, Veena; Ayala, Victor I; Rangaswamy, Sneha P; Kalisz, Irene; Whitney, Stephen; Galmin, Lindsey; Ashraf, Asma; LaBranche, Celia; Montefiori, David; Petrovsky, Nikolai; Kalyanaraman, Vaniambadi S; Pal, Ranajit

    2017-08-01

    The partial success of the RV144 trial underscores the importance of envelope-specific antibody responses for an effective HIV-1 vaccine. Oligomeric HIV-1 envelope proteins delivered with a potent adjuvant are expected to elicit strong antibody responses with broad neutralization specificity. To test this hypothesis, two SIV envelope proteins were formulated with delta inulin-based adjuvant (Advax) and used to immunize nonhuman primates. Oligomeric gp140-gp145 from SIVmac251 and SIVsmE660 was purified to homogeneity. Oligomers showed high-affinity interaction with CD4 and were highly immunogenic in rabbits, inducing Tier 2 SIV-neutralizing antibodies. The immunogenicity of an oligomeric Env DNA prime and protein boost together with Advax was evaluated in Chinese rhesus macaques. DNA administration elicited antibodies to both envelopes, and titres were markedly enhanced following homologous protein boosts via intranasal and intramuscular routes. Strong antibody responses were detected against the V1 and V2 domains of gp120. During peak immune responses, a low to moderate level of neutralizing activity was detected against Tier 1A/1B SIV isolates, with a moderate level noted against a Tier 2 isolate. Increased serum antibody affinity to SIVmac251 gp140 and generation of Env-specific memory B cells were observed in the immunized macaques. Animals were subjected to low-dose intravaginal challenge with SIVmac251 one week after the last protein boost. One out of three immunized animals was protected from infection. Although performed with a small number of macaques, this study demonstrates the utility of oligomeric envelopes formulated with Advax in eliciting broad antibody responses with the potential to provide protection against SIV transmission.

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

    DEFF Research Database (Denmark)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma

    2014-01-01

    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....

  13. Three-Dimensional Visualizations in Teaching Genomics and Bioinformatics: Mutations in HIV Envelope Proteins and Their Consequences for Vaccine Design

    Directory of Open Access Journals (Sweden)

    Kathy Takayama

    2009-11-01

    Full Text Available This project addresses the need to provide a visual context to teach the practical applications of genome sequencing and bioinformatics. Present-day research relies on indirect visualization techniques (e.g., fluorescence-labeling of DNA in sequencing reactions and sophisticated computer analysis. Such methods are impractical and prohibitively expensive for laboratory classes. More importantly, there is a need for curriculum resources that visually demonstrate the application of genome sequence information rather than the DNA sequencing methodology itself. This project is a computer-based lesson plan that engages students in collaborative, problem-based learning. The specific example focuses on approaches to Human Immunodeficiency Virus-1 (HIV-1 vaccine design based on HIV-1 genome sequences using a case study. Students performed comparative alignments of variant HIV-1 sequences available from a public database. Students then examined the consequences of HIV-1 mutations by applying the alignments to three-dimensional images of the HIV-1 envelope protein structure, thus visualizing the implications for applications such as vaccine design. The lesson enhances problem solving through the application of one type of information (genomic or protein sequence into concrete visual conceptualizations. Assessment of student comprehension and problem-solving ability revealed marked improvement after the computer tutorial. Furthermore, contextual presentation of these concepts within a case study resulted in student responses that demonstrated higher levels of cognitive ability than was expected by the instructor.

  14. Epigallocatechin gallate, an active green tea compound inhibits the Zika virus entry into host cells via binding the envelope protein.

    Science.gov (United States)

    Sharma, Nitin; Murali, Aarthy; Singh, Sanjeev Kumar; Giri, Rajanish

    2017-11-01

    Emerging infections of Zika virus (ZIKV) are associated with serious consequences like microcephaly and Guillain-Barré syndrome. It leads to a situation of global health emergency and demand an intensive research investigation to develop safe and effective therapeutics. Various efforts have been made to reduce the pathological pressure of ZIKV, but no effective drug has been introduced against ZIKV infections. A recent study has reported the inhibition of ZIKV entry into the host cells by an active green tea ingredient, Epigallocatechin Gallate (EGCG) in Vero E6cells. The effect of EGCG seems remarkable but lacking the information of the mechanism of action. In this study, we have investigated the binding site (Site1) of EGCG on envelope protein and provided the insights into various interactions of molecule with the binding site using molecular docking studies. Further, using molecular dynamics approaches we proposed the possible associated mechanism of inhibition of ZIKV entry by EGCG molecule. EGCG has found to interact with several residues and providing stability to the protein conformations up to 50ns simulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Human immunodeficiency virus envelope protein Gp120 induces proliferation but not apoptosis in osteoblasts at physiologic concentrations.

    Directory of Open Access Journals (Sweden)

    Nathan W Cummins

    Full Text Available Patients with HIV infection have decreased numbers of osteoblasts, decreased bone mineral density and increased risk of fracture compared to uninfected patients; however, the molecular mechanisms behind these associations remain unclear. We questioned whether Gp120, a component of the envelope protein of HIV capable of inducing apoptosis in many cell types, is able to induce cell death in bone-forming osteoblasts. We show that treatment of immortalized osteoblast-like cells and primary human osteoblasts with exogenous Gp120 in vitro at physiologic concentrations does not result in apoptosis. Instead, in the osteoblast-like U2OS cell line, cells expressing CXCR4, a receptor for Gp120, had increased proliferation when treated with Gp120 compared to control (P<0.05, which was inhibited by pretreatment with a CXCR4 inhibitor and a G-protein inhibitor. This suggests that Gp120 is not an inducer of apoptosis in human osteoblasts and likely does not directly contribute to osteoporosis in infected patients by this mechanism.

  16. Recombinant Envelope-Proteins with Mutations in the Conserved Fusion Loop Allow Specific Serological Diagnosis of Dengue-Infections.

    Directory of Open Access Journals (Sweden)

    Alexandra Rockstroh

    2015-11-01

    Full Text Available Dengue virus (DENV is a mosquito-borne flavivirus and a major international public health concern in many tropical and sub-tropical areas worldwide. DENV is divided into four major serotypes, and infection with one serotype leads to immunity against the same, but not the other serotypes. The specific diagnosis of DENV-infections via antibody-detection is problematic due to the high degree of cross-reactivity displayed by antibodies against related flaviviruses, such as West Nile virus (WNV, Yellow Fever virus (YFV or Tick-borne encephalitis virus (TBEV. Especially in areas where several flaviviruses co-circulate or in the context of vaccination e.g. against YFV or TBEV, this severely complicates diagnosis and surveillance. Most flavivirus cross-reactive antibodies are produced against the highly conserved fusion loop (FL domain in the viral envelope (E protein. We generated insect-cell derived recombinant E-proteins of the four DENV-serotypes which contain point mutations in the FL domain. By using specific mixtures of these mutant antigens, cross-reactivity against heterologous flaviviruses was strongly reduced, enabling sensitive and specific diagnosis of the DENV-infected serum samples in IgG and IgM-measurements. These results have indications for the development of serological DENV-tests with improved specificity.

  17. The Plant TPX2 Protein Regulates Prospindle Assembly before Nuclear Envelope Breakdown

    NARCIS (Netherlands)

    Vos, J.W.; Pieuchot, L.; Evrard, J.L.; Janski, N.; Bergdoll, M.; Ronde, de D.

    2008-01-01

    The Targeting Protein for Xklp2 (TPX2) is a central regulator of spindle assembly in vertebrate cells. The absence or excess of TPX2 inhibits spindle formation. We have defined a TPX2 signature motif that is present once in vertebrate sequences but twice in plants. Plant TPX2 is predominantly

  18. Translocation of proteins across the cell envelope of Gram-positive bacteria

    NARCIS (Netherlands)

    Wely, Karel H.M. van; Swaving, Jelto; Freudl, Roland; Driessen, Arnold J.M.

    2001-01-01

    In contrast to Gram-negative bacteria, secretory proteins of Gram-positive bacteria only need to traverse a single membrane to enter the extracellular environment. For this reason, Gram-positive bacteria (e.g. various Bacillus species) are often used in industry for the commercial production of

  19. Contributions of herpes simplex virus type 1 envelope proteins to entry by endocytosis

    Science.gov (United States)

    Herpes simplex virus (HSV) proteins specifically required for endocytic entry but not direct penetration have not been identified. HSVs deleted of gE, gG, gI, gJ, gM, UL45, or Us9 entered cells via either pH-dependent or pH-independent endocytosis and were inactivated by mildly acidic pH. Thus, the ...

  20. Immunization with truncated envelope protein of Zika virus induces protective immune response in mice

    OpenAIRE

    Han, Jian-Feng; Qiu, Yang; Yu, Jiu-Yang; Wang, Hong-Jiang; Deng, Yong-Qiang; Li, Xiao-Feng; Zhao, Hui; Sun, Han-Xiao; Qin, Cheng-Feng

    2017-01-01

    The global spread of Zika virus (ZIKV) as well as its unexpected link to infant microcephaly have resulted in serious public health concerns. No antiviral drugs against ZIKV is currently available, and vaccine development is of high priority to prepare for potential ZIKV pandemic. In the present study, a truncated E protein with the N-terminal 90% region reserved (E90) from a contemporary ZIKV strain was cloned and expressed in Escherichia coli, purified by a Ni-NTA column, and characterized ...

  1. Identification of two HSP70-related Xenopus oocyte proteins that are capable of recycling across the nuclear envelope

    Energy Technology Data Exchange (ETDEWEB)

    Mandell, R.B.; Feldherr, C.M. (Univ. of Florida, Gainesville (USA))

    1990-11-01

    Two 70-kD polypeptides, B3 and B4, are present in equivalent concentrations in the nucleus and cytoplasm of Xenopus oocytes. The objectives of this study were to determine if they (a) are members of the 70-kD family of heat shock proteins, and (b) recycle between the nuclear and cytoplasmic compartments. Evidence based on high-affinity binding to ATP, cross-reactivity of B3/B4-specific antibodies with rat hsc70, and a comparison of cyanogen bromide cleavage peptide maps with hsc70, verified that B3 and B4 are members of the 70-kD family of heat-shock proteins. Nuclear uptake studies were performed by microinjecting 125I-labeled B3/B4, rat hsc70, and BSA into the cytoplasm of oocytes, and examining their subsequent intracellular distributions. By 6 h postinjection, the nuclear concentration of B3/B4 and hsc70 were approximately 24-fold greater than BSA controls. It was also found that B3/B4-coated gold particles as large as 120A in diameter were able to enter the nucleus by passing through the pores. Nuclear efflux was analyzed by microinjecting the iodinated proteins directly into the oocyte nuclei. 2 h after nuclear injection, at least 46% of the B3/B4 and 60% of the hsc70 were found in the cytoplasmic fractions, compared with less than 10% for the BSA controls. Cell fusion experiments, in which labeled, anucleate oocyte vegetal hemispheres were fused, under oil, with nucleate unlabeled animal hemispheres, demonstrated that cytoplasmic B3 and B4 could enter the nucleus after equilibration was reached, arguing against the existence of separate nuclear and cytoplasmic populations. Collectively, these results show that B3, B4, and rat hsc70 are transported across the nuclear envelope and recycle between the nucleus and cytoplasm.

  2. Nuclear localization of bradykinin B(2) receptors reflects binding to the nuclear envelope protein lamin C.

    Science.gov (United States)

    Takano, Masaoki; Kanoh, Akira; Amako, Katsumi; Otani, Mieko; Sano, Keiji; Kanazawa-Hamada, Michiko; Matsuyama, Shogo

    2014-01-15

    The mechanism of action of bradykinin (BK), a pro-inflammatory mediator, is thought to be mediated by specific cell surface membrane bradykinin B2 receptors. Some evidence suggests that there are both intracellular and nuclear bradykinin B2 receptors. This study identified proteins that interact with the C-terminus of the bradykinin B2 receptor (in particular, the nuclear membrane protein lamin C), using the yeast two-hybrid system. The motif of the C-terminal domain (CT) mutant 303-320 in bradykinin B2 receptor was identified as a lamin C protein binding motif. Immunohistochemistry revealed colocalization of FLAG- bradykinin B2 receptor with HA-lamin C in the nucleus of HEK 293T cells. In situ proximity ligation assay (PLA) showed that FLAG-bradykinin B2 receptor formed heterodimers with HA-lamin C in the nucleus. In addition, live cell fluorescence imaging showed that bradykinin B2 receptor-EGFP was located in the nucleus and co-localized with HcRed-lamin C. Interestingly, neither BK addition nor bradykinin B2 receptor CT mutation reduced the binding to lamin C or changed the distribution of bradykinin B2 receptor. Taken together, these findings demonstrate that bradykinin B2 receptor-lamin C heterodimers form in the nucleus independent of BK stimulation and CT mutation. We propose that heterodimerization of bradykinin B2 receptor with lamin C is essential to nuclear localization of bradykinin B2 receptor and plays an important role in cell signaling and function. © 2013 Elsevier B.V. All rights reserved.

  3. Fitness landscape of the human immunodeficiency virus envelope protein that is targeted by antibodies.

    Science.gov (United States)

    Louie, Raymond H Y; Kaczorowski, Kevin J; Barton, John P; Chakraborty, Arup K; McKay, Matthew R

    2018-01-08

    HIV is a highly mutable virus, and over 30 years after its discovery, a vaccine or cure is still not available. The isolation of broadly neutralizing antibodies (bnAbs) from HIV-infected patients has led to renewed hope for a prophylactic vaccine capable of combating the scourge of HIV. A major challenge is the design of immunogens and vaccination protocols that can elicit bnAbs that target regions of the virus's spike proteins where the likelihood of mutational escape is low due to the high fitness cost of mutations. Related challenges include the choice of combinations of bnAbs for therapy. An accurate representation of viral fitness as a function of its protein sequences (a fitness landscape), with explicit accounting of the effects of coupling between mutations, could help address these challenges. We describe a computational approach that has allowed us to infer a fitness landscape for gp160, the HIV polyprotein that comprises the viral spike that is targeted by antibodies. We validate the inferred landscape through comparisons with experimental fitness measurements, and various other metrics. We show that an effective antibody that prevents immune escape must selectively bind to high escape cost residues that are surrounded by those where mutations incur a low fitness cost, motivating future applications of our landscape for immunogen design. Copyright © 2018 the Author(s). Published by PNAS.

  4. Characterization of p18, a component of the lamin B receptor complex and a new integral membrane protein of the avian erythrocyte nuclear envelope.

    Science.gov (United States)

    Simos, G; Maison, C; Georgatos, S D

    1996-05-24

    Employing avian erythrocytes, we have previously isolated a multimeric complex consisting of the lamin B receptor (LBR, or p58), the nuclear lamins, an LBR-specific kinase, a 34-kDa protein, and an 18-kDa polypeptide termed p18. As the LBR kinase and the 34-kDa component have been recently characterized, we now proceed in the characterization of p18. We show here that p18 is an integral membrane protein specific to the erythrocyte nuclear envelope which binds to LBR and B-type lamins. NH2-terminal sequencing indicates that p18 is distinct from other nuclear envelope components, but has similarity to the mitochondrial isoquinoline-binding protein. In situ analysis by immunoelectron microscopy and examination of digitonin-permeabilized cells by indirect immunofluorescence show that p18, unlike LBR and other lamin-binding proteins, is equally distributed between the inner and outer nuclear membrane. Furthermore, cycloheximide inhibition experiments reveal that the fraction of p18 that resides in the outer nuclear membrane does not represent nascent chains en route to the inner nuclear membrane, but rather material in equilibrium with the p18 that partitions with the inner nuclear membrane. The paradigm of p18 suggests that transmembrane complexes formed by the nuclear lamins and LBR provide potential docking sites for integral membrane proteins of the nuclear envelope that equilibrate between the rough endoplasmic reticulum and the inner nuclear membrane.

  5. Chimeric hepatitis B virus/hepatitis C virus envelope proteins elicit broadly neutralizing antibodies and constitute a potential bivalent prophylactic vaccine.

    Science.gov (United States)

    Beaumont, Elodie; Patient, Romuald; Hourioux, Christophe; Dimier-Poisson, Isabelle; Roingeard, Philippe

    2013-04-01

    The development of a prophylactic vaccine against hepatitis C virus (HCV) has become an important medical priority, because 3-4 million new HCV infections are thought to occur each year worldwide. Hepatitis B virus (HBV) is another major human pathogen, but infections with this virus can be prevented with a safe, efficient vaccine, based on the remarkable ability of the envelope protein (S) of this virus to self-assemble into highly immunogenic subviral particles. Chimeric HBV-HCV envelope proteins in which the N-terminal transmembrane domain of S was replaced with the transmembrane domain of the HCV envelope proteins (E1 or E2) were efficiently coassembled with the wild-type HBV S protein into subviral particles. These chimeric particles presented the full-length E1 and E2 proteins from a genotype 1a virus in an appropriate conformation for formation of the E1-E2 heterodimer. Produced in stably transduced Chinese hamster ovary cells and used to immunize New Zealand rabbits, these particles induced a strong specific antibody (Ab) response against the HCV and HBV envelope proteins in immunized animals. Sera containing anti-E1 or anti-E2 Abs elicited by these particles neutralized infections with HCV pseudoparticles and cell-cultured viruses derived from different heterologous 1a, 1b, 2a, and 3 strains. Moreover, the anti-hepatitis B surface response induced by these chimeric particles was equivalent to the response induced by a commercial HBV vaccine. Our results provide support for approaches based on the development of bivalent HBV-HCV prophylactic vaccine candidates potentially able to prevent initial infection with either of these two hepatotropic viruses. Copyright © 2012 American Association for the Study of Liver Diseases.

  6. Virus-like particles that display Zika virus envelope protein domain III induce potent neutralizing immune responses in mice.

    Science.gov (United States)

    Yang, Ming; Lai, Huafang; Sun, Haiyan; Chen, Qiang

    2017-08-09

    Several Zika virus (ZIKV) vaccine candidates have recently been described which use inactivated whole virus, DNA or RNA that express the virus' Envelope (E) glycoprotein as the antigen. These were successful in stimulating production of virus-targeted antibodies that protected animals against ZIKV challenges, but their use potentially will predispose vaccinated individuals to infection by the related Dengue virus (DENV). We have devised a virus like particle (VLP) carrier based on the hepatitis B core antigen (HBcAg) that displays the ZIKV E protein domain III (zDIII), and shown that it can be produced quickly and easily purified in large quantities from Nicotiana benthamiana plants. HBcAg-zDIII VLPs are shown to be highly immunogenic, as two doses elicited potent humoral and cellular responses in mice that exceed the threshold correlated with protective immunity against multiple strains of Zika virus. Notably, HBcAg-zDIII VLPs-elicited antibodies did not enhance the infection of DENV in Fc gamma receptor-expressing cells, offsetting the concern of ZIKV vaccines inducing cross-reactive antibodies and sensitizing people to subsequent DENV infection. Thus, our zDIII-based vaccine offers improved safety and lower cost production than other current alternatives, with equivalent effectiveness.

  7. Immunization with truncated envelope protein of Zika virus induces protective immune response in mice.

    Science.gov (United States)

    Han, Jian-Feng; Qiu, Yang; Yu, Jiu-Yang; Wang, Hong-Jiang; Deng, Yong-Qiang; Li, Xiao-Feng; Zhao, Hui; Sun, Han-Xiao; Qin, Cheng-Feng

    2017-08-30

    The global spread of Zika virus (ZIKV) as well as its unexpected link to infant microcephaly have resulted in serious public health concerns. No antiviral drugs against ZIKV is currently available, and vaccine development is of high priority to prepare for potential ZIKV pandemic. In the present study, a truncated E protein with the N-terminal 90% region reserved (E90) from a contemporary ZIKV strain was cloned and expressed in Escherichia coli, purified by a Ni-NTA column, and characterized by Western blotting assays. Immunization with recombinant E90 induced robust ZIKV-specific humoral response in adult BALB/c mice. Passive transfer of the antisera from E90-immunized mice conferred full protection against lethal ZIKV challenge in a neonatal mice model. Our results indicate that recombinant ZIKV E90 described here represents as a promising ZIKV subunit vaccine that deserves further clinical development.

  8. Tecovirimat, a p37 envelope protein inhibitor for the treatment of smallpox infection.

    Science.gov (United States)

    Duraffour, Sophie; Andrei, Graciela; Snoeck, Robert

    2010-03-01

    Since the eradication of naturally occurring smallpox in 1980, the fear that variola virus could be used as a biological weapon has become real. Over the last 10 years, emergency preparedness programs have been launched to protect populations against a smallpox outbreak or the possible emergence in humans of other orthopoxvirus infections, such as monkeypox. Vaccination against smallpox was responsible for its eradication, but was linked with high rates of adverse events and contraindications. In this context, intensive research in the poxvirus field has led to the development of safer vaccines and to an increase in the number of anti-poxvirus agents in the pipeline. SIGA Technologies Inc, under license from ViroPharma Inc, is developing tecovirimat (ST-246). Tecovirimat is a novel antiviral that inhibits the egress of orthopoxviruses by targeting viral p37 protein orthologs. The development of tecovirimat during the last 5 years for the treatment of smallpox and for its potential use as adjunct to smallpox vaccine is reviewed here.

  9. Nelfinavir impairs glycosylation of herpes simplex virus 1 envelope proteins and blocks virus maturation.

    Science.gov (United States)

    Gantt, Soren; Gachelet, Eliora; Carlsson, Jacquelyn; Barcy, Serge; Casper, Corey; Lagunoff, Michael

    2015-01-01

    Nelfinavir (NFV) is an HIV-1 aspartyl protease inhibitor that has numerous effects on human cells, which impart attractive antitumor properties. NFV has also been shown to have in vitro inhibitory activity against human herpesviruses (HHVs). Given the apparent absence of an aspartyl protease encoded by HHVs, we investigated the mechanism of action of NFV herpes simplex virus type 1 (HSV-1) in cultured cells. Selection of HSV-1 resistance to NFV was not achieved despite multiple passages under drug pressure. NFV did not significantly affect the level of expression of late HSV-1 gene products. Normal numbers of viral particles appeared to be produced in NFV-treated cells by electron microscopy but remain within the cytoplasm more often than controls. NFV did not inhibit the activity of the HSV-1 serine protease nor could its antiviral activity be attributed to inhibition of Akt phosphorylation. NFV was found to decrease glycosylation of viral glycoproteins B and C and resulted in aberrant subcellular localization, consistent with induction of endoplasmic reticulum stress and the unfolded protein response by NFV. These results demonstrate that NFV causes alterations in HSV-1 glycoprotein maturation and egress and likely acts on one or more host cell functions that are important for HHV replication.

  10. Nelfinavir Impairs Glycosylation of Herpes Simplex Virus 1 Envelope Proteins and Blocks Virus Maturation

    Directory of Open Access Journals (Sweden)

    Soren Gantt

    2015-01-01

    Full Text Available Nelfinavir (NFV is an HIV-1 aspartyl protease inhibitor that has numerous effects on human cells, which impart attractive antitumor properties. NFV has also been shown to have in vitro inhibitory activity against human herpesviruses (HHVs. Given the apparent absence of an aspartyl protease encoded by HHVs, we investigated the mechanism of action of NFV herpes simplex virus type 1 (HSV-1 in cultured cells. Selection of HSV-1 resistance to NFV was not achieved despite multiple passages under drug pressure. NFV did not significantly affect the level of expression of late HSV-1 gene products. Normal numbers of viral particles appeared to be produced in NFV-treated cells by electron microscopy but remain within the cytoplasm more often than controls. NFV did not inhibit the activity of the HSV-1 serine protease nor could its antiviral activity be attributed to inhibition of Akt phosphorylation. NFV was found to decrease glycosylation of viral glycoproteins B and C and resulted in aberrant subcellular localization, consistent with induction of endoplasmic reticulum stress and the unfolded protein response by NFV. These results demonstrate that NFV causes alterations in HSV-1 glycoprotein maturation and egress and likely acts on one or more host cell functions that are important for HHV replication.

  11. Use of envelope domain III protein for detection and differentiation of flaviviruses in the Free State Province, South Africa.

    Science.gov (United States)

    Mathengtheng, Lehlohonolo; Burt, Felicity J

    2014-04-01

    The presence of the mosquito-borne flavivirus species West Nile virus (WNV) and Wesselsbron virus (WESSV) in southern Africa is well established; however, their true prevalence remains unknown. To date, the presence of tick-borne flaviviruses has not been confirmed in this region. Serological assays using reagents that can be handled in a biosafety level 2 or lower facility were developed and evaluated for the detection and differentiation of tick- and mosquito-borne flaviviruses in the Free State province of South Africa. A total of 2393 serum samples from a variety of species including humans, cattle, and sheep were tested using Kunjin virus (KUNV) cell lysate antigen for the detection of anti-flavivirus antibodies in an indirect immunoglobulin G (IgG) enzyme-linked immonosorbent assay (ELISA). To further differentiate positive reactors on the KUNV assay for antibodies against tick- or mosquito-borne flaviviruses, recombinant envelope domain III (r-EDIII) proteins of Langat virus (LGTV), WNV, and WESSV were expressed in a bacterial expression system and used in ELISA. A total of 722 samples were positive using the KUNV assay, of which 71, 457, and 431 were positive using the r-LGTVEDIII, r-WNVEDIII, and r-WESSVEDIII assays, respectively. A total of 70 samples were reactive using the KUNV assay but not using any of the other assays, suggesting that there are possibly other flaviviruses circulating in the Free State province for which specific r-EDIII assays were not available. Collectively, the results suggest a strong presence of flaviviruses co-circulating in the Free State province with an abundance of mosquito-borne flaviviruses. There is evidence suggesting the presence of tick-borne flaviviruses, but it has yet to be confirmed. The EDIII protein is a useful tool that can be used in the detection and differentiation of flaviviruses in resource-limited laboratories, but virus neutralization assays are suggested for accurate confirmation of results.

  12. Comparative proteomics of chloroplasts envelopes from bundle sheath and mesophyll chloroplasts reveals novel membrane proteins with a possible role in C4-related metabolite fluxes and development.

    Directory of Open Access Journals (Sweden)

    Kalpana eManandhar-Shrestha

    2013-03-01

    Full Text Available As the world population grows, our need for food increases drastically. Limited amounts of arable land lead to a competition between food and fuel crops, while changes in the global climate may impact future crop yields. Thus, a second green revolution will need a better understanding of the processes essential for plant growth and development. One approach toward the solution of this problem is to better understand regulatory and transport processes in C4 plants. C4 plants display an up to 10-fold higher apparent CO2 assimilation and higher yields while maintaining high water use efficiency. This requires differential regulation of mesophyll (M and bundle sheath (BS chloroplast development as well as higher metabolic fluxes of photosynthetic intermediates between cells and across chloroplast envelopes. While previous analyses of overall chloroplast membranes have yielded significant insight, our comparative proteomics approach using enriched BS and M chloroplast envelopes of Zea mays allowed us to identify 37 proteins of unknown function that have not been seen in these earlier studies. We identified 280 proteins, 84% of which are known/predicted to be present in chloroplasts (cp. 74% have a known or predicted membrane association. 21 membrane proteins were 2-15 times more abundant in BS cells, while 36 proteins were more abundant in M cp envelopes. These proteins could represent additional candidates of proteins essential for development or metabolite transport processes in C4 plants. RT-PCR confirmed differential expression of thirteen candidate genes. Cp association was confirmed using GFP labeling. Genes for a PIC-like protein and an ER-AP-like protein show an early transient increase in gene expression during the transition to light. In addition, PIC gene expression is increased in the immature part of the leaf and was lower in the fully developed parts of the leaf, suggesting a need for/incorporation of the protein during chloroplast

  13. Reactions of the envelope proteins of bacteria from uranium spoil banks with heavy metals; Wechselwirkungen der Huellproteine von Bakterien aus Uranabfallhalden mit Schwermetallen

    Energy Technology Data Exchange (ETDEWEB)

    Raff, J.

    2002-10-01

    New envelope proteins of the Bacillus type were to be isolated from uranium spoil banks and analyzed structurally and from the view of molecular biology. Direct interactions of palladium, platinum and uranium were observed with the envelope proteins of B. sphaericus JG-A12 and NCTC 9602. The binding capacity of biologized ceramics (bioceres) for uranium and copper was 2.7-42 times higher than the binding capacity of other materials used for soil regeneration. Further characteristics of bioceres are full-scale regenerability and the possibility of varying their porosity by freeze-drying or by adding penetration agents like sorbit. This leads to faster sorption and desorption of uranium and copper. (orig.)

  14. Characterization of the TolB-Pal trans-envelope complex from Xylella fastidiosa reveals a dynamic and coordinated protein expression profile during the biofilm development process.

    Science.gov (United States)

    Santos, Clelton A; Janissen, Richard; Toledo, Marcelo A S; Beloti, Lilian L; Azzoni, Adriano R; Cotta, Monica A; Souza, Anete P

    2015-10-01

    The intriguing roles of the bacterial Tol-Pal trans-envelope protein complex range from maintenance of cell envelope integrity to potential participation in the process of cell division. In this study, we report the characterization of the XfTolB and XfPal proteins of the Tol-Pal complex of Xylella fastidiosa. X. fastidiosa is a major plant pathogen that forms biofilms inside xylem vessels, triggering the development of diseases in important cultivable plants around the word. Based on functional complementation experiments in Escherichia coli tolB and pal mutant strains, we confirmed the role of xftolB and xfpal in outer membrane integrity. In addition, we observed a dynamic and coordinated protein expression profile during the X. fastidiosa biofilm development process. Using small-angle X-ray scattering (SAXS), the low-resolution structure of the isolated XfTolB-XfPal complex in solution was solved for the first time. Finally, the localization of the XfTolB and XfPal polar ends was visualized via immunofluorescence labeling in vivo during bacterial cell growth. Our results highlight the major role of the components of the cell envelope, particularly the TolB-Pal complex, during the different phases of bacterial biofilm development. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins.

    Science.gov (United States)

    Maric, Martina; Haugo, Alison C; Dauer, William; Johnson, David; Roller, Richard J

    2014-07-01

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. INTERNAL ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  17. Expression and structural properties of a chimeric protein based on the ectodomains of E1 and E2 hepatitis C virus envelope glycoproteins

    OpenAIRE

    Tello, Daniel; Rodríguez-Rodríguez, Mar; Yélamos, Belén; Gómez-Gutiérrez, Julián; Ortega, Sara; Pacheco, Beatriz; Peterson, Darrell L.; Gavilanes, Francisco

    2010-01-01

    Hepatitis C virus encodes two enveloped glycoproteins, E1 and E2, which are involved in viral attachment and entry into target cells. We have obtained in insect cells infected by recombinant baculovirus a chimeric secreted recombinant protein, E1341E2661, containing the ectodomains of E1 and E2. The described procedure allows the purification of approximately 2 mg of protein from 1 L of culture media. Sedimentation velocity experiments and SDS-PAGE in the absence of reducing agents indicate t...

  18. The Use of Two-Photon FRET-FLIM to Study Protein Interactions During Nuclear Envelope Fusion In Vivo and In Vitro.

    Science.gov (United States)

    Byrne, Richard D; Larijani, Banafshé; Poccia, Dominic L

    2016-01-01

    FRET-FLIM techniques have wide application in the study of protein and protein-lipid interactions in cells. We have pioneered an imaging platform for accurate detection of functional states of proteins and their interactions in fixed cells. This platform, two-site-amplified Förster resonance energy transfer (a-FRET), allows greater signal generation while retaining minimal noise thus enabling application of fluorescence lifetime imaging microscopy (FLIM) to be routinely deployed in different types of cells and tissue. We have used the method described here, time-resolved FRET monitored by two-photon FLIM, to demonstrate the direct interaction of Phospholipase Cγ (PLCγ) by Src Family Kinase 1 (SFK1) during nuclear envelope formation and during male and female pronuclear membrane fusion in fertilized sea urchin eggs. We describe here a generic method that can be applied to monitor any proteins of interest.

  19. Primary structure analysis and lamin B and DNA binding of human LBR, an integral protein of the nuclear envelope inner membrane.

    Science.gov (United States)

    Ye, Q; Worman, H J

    1994-04-15

    We have determined the primary structure of human LBR, an integral protein of the nuclear envelope inner membrane, and examined its interactions with lamin B and DNA. Human LBR is 68% identical to the chicken lamin B receptor and has a basic nucleoplasmic amino-terminal domain of 208 amino acids followed by a hydrophobic domain with eight putative transmembrane segments. The amino-terminal domain contains a Ser-Arg-rich stretch and consensus sites for phosphorylation by protein kinase A and p34cdc2 protein kinase. A fusion protein containing the amino-terminal domain of human LBR is recognized by autoantibodies from patients with primary biliary cirrhosis, and these serum antibodies label the nuclear envelope when examined by immunofluorescence microscopy. The LBR amino-terminal domain precipitates lamin B from nuclear extracts and retards the migration of double-stranded DNA subjected to agarose gel electrophoresis. When immobilized on nitrocellulose, the amino-terminal domain of LBR also associates with DNA, and the stretch between amino acids 71 and 100, which contains the Ser-Arg-rich stretch, is necessary for DNA binding. These results demonstrate that LBR is conserved among vertebrate species and that its nucleoplasmic domain can potentially mediate the interaction of both the nuclear lamina and the chromatin with the inner nuclear membrane.

  20. Hepatitis C virus expressing flag-tagged envelope protein 2 has unaltered infectivity and density, is specifically neutralized by flag antibodies and can be purified by affinity chromatography

    DEFF Research Database (Denmark)

    Prentø, Jannick Cornelius; Bukh, Jens

    2011-01-01

    Hepatitis C virus (HCV) purification by ultracentrifugation is difficult because of the low and heterogeneous density of native and cultured viruses. It was recently shown that inserting flag tag into envelope protein 2 (E2) of HCV permitted virus purification by affinity chromatography. However...... to the original virus. Flag-tagged virus was susceptible to flag-specific antibody neutralization, and infected cells could be immuno-stained by anti-flag antibodies. Using affinity chromatography with anti-flag resin we repeatedly obtained ~30% recovery of infectious particles. The full viability and unaltered...

  1. A Tyrosine-Based Trafficking Motif of the Tegument Protein pUL71 Is Crucial for Human Cytomegalovirus Secondary Envelopment.

    Science.gov (United States)

    Dietz, Andrea N; Villinger, Clarissa; Becker, Stefan; Frick, Manfred; von Einem, Jens

    2018-01-01

    The human cytomegalovirus (HCMV) tegument protein pUL71 is required for efficient secondary envelopment and accumulates at the Golgi compartment-derived viral assembly complex (vAC) during infection. Analysis of various C-terminally truncated pUL71 proteins fused to enhanced green fluorescent protein (eGFP) identified amino acids 23 to 34 as important determinants for its Golgi complex localization. Sequence analysis and mutational verification revealed the presence of an N-terminal tyrosine-based trafficking motif (YXXΦ) in pUL71. This led us to hypothesize a requirement of the YXXΦ motif for the function of pUL71 in infection. Mutation of both the tyrosine residue and the entire YXXΦ motif resulted in an altered distribution of mutant pUL71 at the plasma membrane and in the cytoplasm during infection. Both YXXΦ mutant viruses exhibited similarly decreased focal growth and reduced virus yields in supernatants. Ultrastructurally, mutant-virus-infected cells exhibited impaired secondary envelopment manifested by accumulations of capsids undergoing an envelopment process. Additionally, clusters of capsid accumulations surrounding the vAC were observed, similar to the ultrastructural phenotype of a UL71-deficient mutant. The importance of endocytosis and thus the YXXΦ motif for targeting pUL71 to the Golgi complex was further demonstrated when clathrin-mediated endocytosis was inhibited either by coexpression of the C-terminal part of cellular AP180 (AP180-C) or by treatment with methyl-β-cyclodextrin. Both conditions resulted in a plasma membrane accumulation of pUL71. Altogether, these data reveal the presence of a functional N-terminal endocytosis motif that is an important determinant for intracellular localization of pUL71 and that is furthermore required for the function of pUL71 during secondary envelopment of HCMV capsids at the vAC. IMPORTANCE Human cytomegalovirus (HCMV) is the leading cause of birth defects among congenital virus infections and can

  2. SAFEGUARDS ENVELOPE

    Energy Technology Data Exchange (ETDEWEB)

    Duc Cao; Richard Metcalf

    2010-07-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details advanced statistical techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z-testing. A brief analysis of the impact of the safeguards optimization on the rest of plant efficiency, criticality concerns, and overall requirements is presented.

  3. Hepatitis C Virus Proteins Interact with the Endosomal Sorting Complex Required for Transport (ESCRT Machinery via Ubiquitination To Facilitate Viral Envelopment

    Directory of Open Access Journals (Sweden)

    Rina Barouch-Bentov

    2016-11-01

    Full Text Available Enveloped viruses commonly utilize late-domain motifs, sometimes cooperatively with ubiquitin, to hijack the endosomal sorting complex required for transport (ESCRT machinery for budding at the plasma membrane. However, the mechanisms underlying budding of viruses lacking defined late-domain motifs and budding into intracellular compartments are poorly characterized. Here, we map a network of hepatitis C virus (HCV protein interactions with the ESCRT machinery using a mammalian-cell-based protein interaction screen and reveal nine novel interactions. We identify HRS (hepatocyte growth factor-regulated tyrosine kinase substrate, an ESCRT-0 complex component, as an important entry point for HCV into the ESCRT pathway and validate its interactions with the HCV nonstructural (NS proteins NS2 and NS5A in HCV-infected cells. Infectivity assays indicate that HRS is an important factor for efficient HCV assembly. Specifically, by integrating capsid oligomerization assays, biophysical analysis of intracellular viral particles by continuous gradient centrifugations, proteolytic digestion protection, and RNase digestion protection assays, we show that HCV co-opts HRS to mediate a late assembly step, namely, envelopment. In the absence of defined late-domain motifs, K63-linked polyubiquitinated lysine residues in the HCV NS2 protein bind the HRS ubiquitin-interacting motif to facilitate assembly. Finally, ESCRT-III and VPS/VTA1 components are also recruited by HCV proteins to mediate assembly. These data uncover involvement of ESCRT proteins in intracellular budding of a virus lacking defined late-domain motifs and a novel mechanism by which HCV gains entry into the ESCRT network, with potential implications for other viruses.

  4. Vaccinia virus intracellular enveloped virions move to the cell periphery on microtubules in the absence of the A36R protein.

    Science.gov (United States)

    Herrero-Martínez, Esteban; Roberts, Kim L; Hollinshead, Michael; Smith, Geoffrey L

    2005-11-01

    Vaccinia virus (VACV) intracellular enveloped virus (IEV) particles are transported to the cell periphery on microtubules where they fuse with the plasma membrane to form cell-associated enveloped virus (CEV). Two IEV-specific proteins, F12L and A36R, are implicated in mediating transport of IEV. Without F12L, virus morphogenesis halts after formation of IEV, and CEV is not formed, whereas without A36R, IEV was reported not to be transported, yet CEV was formed, To address the roles of A36R and F12L in IEV transport, viruses with deletions of either F12L (vdeltaF12L) or A36R (vdeltaA36R) were labelled with enhanced green fluorescent protein (EGFP) fused to the core protein A5L, and used to follow CEV production with time. Without F12L, CEV production was inhibited by >99 %, whereas without A36R, CEV were produced at approximately 60 % of wild-type levels at 24 h post-infection. Depolymerization of microtubules, but not actin, inhibited CEV formation in vdeltaA36R-infected cells. Moreover, vdeltaA36R IEV labelled with EGFP fused to the B5R protein co-localized with microtubules, showing that the A36R protein is not required for the interaction of IEV with microtubules. Time-lapse confocal microscopy confirmed that both wild-type and vdeltaA36R IEV moved in a stop-start manner at speeds consistent with microtubular movement, although the mean length of vdeltaA36R IEV movement was shorter. These data demonstrate that VACV IEV is transported to the cell surface using microtubules in the absence of A36R, and therefore IEV must attach to microtubule motors using at least one protein other than A36R.

  5. GB virus C particles inhibit T cell activation via envelope E2 protein-mediated inhibition of T cell receptor signaling

    Science.gov (United States)

    Bhattarai, Nirjal; McLinden, James H.; Xiang, Jinhua; Landay, Alan L.; Chivero, Ernest T.; Stapleton, Jack T.

    2014-01-01

    Viruses enter into complex interactions within human hosts leading to facilitation or suppression of each other's replication. Upon coinfection, GB virus C (GBV-C) suppresses HIV-1 replication in vivo and in vitro, and GBV-C coinfection is associated with prolonged survival in HIV-infected people. GBV-C is a lymphotropic virus capable of persistent infection. GBV-C infection is associated with reduced T cell activation in HIV-infected humans, and immune activation is a critical component of HIV disease pathogenesis. We demonstrate that serum GBV-C particles inhibited activation of primary human T cells. T cell activation inhibition was mediated by the envelope glycoprotein E2, as expression of E2 inhibited T cell receptor (TCR)-mediated activation of tyrosine kinase (Lck). The region on the E2 protein was characterized and revealed a highly conserved peptide motif sufficient to inhibit TCR-mediated signaling. The E2 region contained a predicted Lck substrate site, and substitution of an alanine or histidine for the tyrosine reversed TCR signaling inhibition. GBV-C E2 protein and a synthetic peptide representing the inhibitory amino acid sequence were phosphorylated by Lck in vitro. The synthetic peptide also inhibited TCR-mediated activation of primary human CD4+ and CD8+ T cells. Extracellular microvesicles from GBV-C E2-expressing cells contained E2 protein and inhibited TCR signaling in bystander T cells not expressing E2. Thus, GBV-C reduced global T cell activation via competition between its envelope protein E2 and Lck following TCR engagement. This novel inhibitory mechanism of T cell activation may provide new approaches for HIV and immunoactivation therapy. PMID:23686495

  6. The nucleocapsid protein of an enveloped plant virus, Tomato spotted wilt virus, facilitates long-distance movement of Tobacco mosaic virus hybrids.

    Science.gov (United States)

    Zhang, Yongqiang; Zhang, Chao; Li, Weimin

    2012-01-01

    To investigate the potential role(s) of the nucleocapsid (N) protein of Tomato spotted wilt virus (TSWV), the open reading frame for the N protein was expressed from a Tobacco mosaic virus (TMV)-based vector encoding only the TMV replicase proteins. In the absence of other TSWV-encoded proteins, the transiently expressed N protein facilitated long-distance movement of the TMV-based hybrids in transgenic Nicotiana benthamiana [NB-MP(+)] expressing movement protein of TMV, thus providing the functional demonstration of the N protein in long-distance RNA movement. Removal of the N-terminal 39 amino acids (N-NΔ39), the C-terminal 26 amino acids (N-CΔ26) or both of them (N-NΔ39CΔ26) abolished the long-distance movement function, indicating the essential role of both N- and C-terminus. In contrast, alanine substitution of the phenylalanines at positions 242 and 246 (N242/262A), two crucial amino acids for homotypic interaction of the N protein, had little effect, suggesting that the N protein could function in long-distance movement in the form of monomers. In addition, both the wild type N and the alanine mutant N242/262A hardly induced local symptoms in NB-MP(+) plants and TMV-MP transgenic N. tabacum cv. Xanthi. The deletion mutants N-NΔ39, N-CΔ26 and N-NΔ39CΔ26, however, induced apparent symptoms of necrotic ringspots, necrosis or chlorotic spots in all inoculated leaves. On the basis of these findings, the potential role of N during the TSWV infection was discussed. To our knowledge, this is the first report that the N protein of an enveloped plant virus functioned in long-distance movement. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Cold co-extraction of hemagglutinin and matrix M1 protein from influenza virus A by a combination of non-ionic detergents allows for visualization of the raft-like nature of the virus envelope.

    Science.gov (United States)

    Radyukhin, V; Fedorova, N; Ksenofontov, A; Serebryakova, M; Baratova, L

    2008-01-01

    Membrane solubilization with a mixture of cold non-ionic detergents has been applied to isolate detergent-resistant membranes from intact virus A lipid bilayer. Association of the viral envelope glycoproteins and M1 into a raft lipid-protein complex was verified via detergent insolubility experiments, and the M1:HA stoichiometry of the proposed supramolecular complex was estimated via amino acid analysis. Electron microscopy and dynamic light scattering data revealed that these lipid-protein rafts form unilamellar vesicles with HA spikes on their surfaces similar to influenza virus virions. Together, our data suggest that the cold co-extraction technique visualizes the raft-like nature of the viral envelope and demonstrates the interaction of matrix M1 protein with the envelope.

  8. A nuclear envelope-associated kinase phosphorylates arginine-serine motifs and modulates interactions between the lamin B receptor and other nuclear proteins.

    Science.gov (United States)

    Nikolakaki, E; Simos, G; Georgatos, S D; Giannakouros, T

    1996-04-05

    Previous studies have identified a subassembly of nuclear envelope proteins, termed "the LBR complex." This complex includes the lamin B receptor protein (LBR or p58), a kinase which phosphorylates LBR in a constitutive fashion (LBR kinase), the nuclear lamins A and B, an 18-kDa polypeptide (p18), and a 34-kDa protein (p34/p32). The latter polypeptide has been shown to interact with the HIV-1 proteins Rev and Tat and with the splicing factor 2 (SF2). Using recombinant proteins produced in bacteria and synthetic peptides representing different regions of LBR, we now show that the LBR kinase modifies specifically arginine-serine (RS) dipeptide motifs located at the nucleoplasmic, NH2-terminal domain of LBR and in members of the SR family of splicing factors. Furthermore, we show that the NH2-terminal domain of LBR binds to p34/p32, whereas a mutated domain lacking the RS region does not. Phosphorylation of LBR by the RS kinase completely abolishes binding of p34/p32, suggesting that this enzyme regulates interactions among the components of the LBR complex.

  9. Definition of novel cell envelope associated proteins in Triton X-114 extracts of Mycobacterium tuberculosis H37Rv

    Directory of Open Access Journals (Sweden)

    Søfteland Tina

    2010-04-01

    Full Text Available Abstract Background Membrane- and membrane-associated proteins are important for the pathogenicity of bacteria. We have analysed the content of these proteins in virulent Mycobacterium tuberculosis H37Rv using Triton X-114 detergent-phase separation for extraction of lipophilic proteins, followed by their identification with high resolution mass spectrometry. Results In total, 1417 different proteins were identified. In silico analysis of the identified proteins revealed that 248 proteins had at least one predicted trans-membrane region. Also, 64 of the identified proteins were predicted lipoproteins, and 54 proteins were predicted as outer membrane proteins. Three-hundred-and-ninety-five of the observed proteins, including 91 integral membrane proteins were described for the first time. Comparison of abundance levels of the identified proteins was performed using the exponentially modified protein abundance index (emPAI which takes into account the number of the observable peptides to the number of experimentally observed peptide ions for a given protein. The outcome showed that among the membrane-and membrane-associated proteins several proteins are present with high relative abundance. Further, a close examination of the lipoprotein LpqG (Rv3623 which is only detected in the membrane fractions of M. tuberculosis but not in M. bovis, revealed that the homologous gene in M. bovis lack the signal peptide and lipobox motif, suggesting impaired export to the membrane. Conclusions Altogether, we have identified a substantial proportion of membrane- and membrane-associated proteins of M. tuberculosis H37Rv, compared the relative abundance of the identified proteins and also revealed subtle differences between the different members of the M. tuberculosis complex.

  10. Co-expression of foreign proteins tethered to HIV-1 envelope glycoprotein on the cell surface by introducing an intervening second membrane-spanning domain.

    Directory of Open Access Journals (Sweden)

    Hongyun Wang

    Full Text Available The envelope glycoprotein (Env of human immunodeficiency virus type I (HIV-1 mediates membrane fusion. To analyze the mechanism of HIV-1 Env-mediated membrane fusion, it is desirable to determine the expression level of Env on the cell surface. However, the quantification of Env by immunological staining is often hampered by the diversity of HIV-1 Env and limited availability of universal antibodies that recognize different Envs with equal efficiency. To overcome this problem, here we linked a tag protein called HaloTag at the C-terminus of HIV-1 Env. To relocate HaloTag to the cell surface, we introduced a second membrane-spanning domain (MSD between Env and HaloTag. The MSD of transmembrane protease serine 11D, a type II transmembrane protein, successfully relocated HaloTag to the cell surface. The surface level of Env can be estimated indirectly by staining HaloTag with a specific membrane-impermeable fluorescent ligand. This tagging did not compromise the fusogenicity of Env drastically. Furthermore, fusogenicity of Env was preserved even after the labeling with the ligands. We have also found that an additional foreign peptide or protein such as C34 or neutralizing single-chain variable fragment (scFv can be linked to the C-terminus of the HaloTag protein. Using these constructs, we were able to determine the required length of C34 and critical residues of neutralizing scFv for blocking membrane fusion, respectively.

  11. Co-expression of foreign proteins tethered to HIV-1 envelope glycoprotein on the cell surface by introducing an intervening second membrane-spanning domain.

    Science.gov (United States)

    Wang, Hongyun; Li, Xiao; Nakane, Shuhei; Liu, Shujun; Ishikawa, Hirohito; Iwamoto, Aikichi; Matsuda, Zene

    2014-01-01

    The envelope glycoprotein (Env) of human immunodeficiency virus type I (HIV-1) mediates membrane fusion. To analyze the mechanism of HIV-1 Env-mediated membrane fusion, it is desirable to determine the expression level of Env on the cell surface. However, the quantification of Env by immunological staining is often hampered by the diversity of HIV-1 Env and limited availability of universal antibodies that recognize different Envs with equal efficiency. To overcome this problem, here we linked a tag protein called HaloTag at the C-terminus of HIV-1 Env. To relocate HaloTag to the cell surface, we introduced a second membrane-spanning domain (MSD) between Env and HaloTag. The MSD of transmembrane protease serine 11D, a type II transmembrane protein, successfully relocated HaloTag to the cell surface. The surface level of Env can be estimated indirectly by staining HaloTag with a specific membrane-impermeable fluorescent ligand. This tagging did not compromise the fusogenicity of Env drastically. Furthermore, fusogenicity of Env was preserved even after the labeling with the ligands. We have also found that an additional foreign peptide or protein such as C34 or neutralizing single-chain variable fragment (scFv) can be linked to the C-terminus of the HaloTag protein. Using these constructs, we were able to determine the required length of C34 and critical residues of neutralizing scFv for blocking membrane fusion, respectively.

  12. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Roehrig, John T., E-mail: jtr1@cdc.gov [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Butrapet, Siritorn; Liss, Nathan M. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Bennett, Susan L. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  13. Bacillus anthracis Sortase A (SrtA) Anchors LPXTG Motif-Containing Surface Proteins to the Cell Wall Envelope

    OpenAIRE

    Gaspar, Andrew H.; Marraffini, Luciano A.; Glass, Elizabeth M.; DeBord, Kristin L.; Ton-That, Hung; Schneewind, Olaf

    2005-01-01

    Cell wall-anchored surface proteins of gram-positive pathogens play important roles during the establishment of many infectious diseases, but the contributions of surface proteins to the pathogenesis of anthrax have not yet been revealed. Cell wall anchoring in Staphylococcus aureus occurs by a transpeptidation mechanism requiring surface proteins with C-terminal sorting signals as well as sortase enzymes. The genome sequence of Bacillus anthracis encodes three sortase genes and eleven surfac...

  14. Molecular contacts for chlorosome envelope proteins revealed by cross-linking studies with chlorosomes from Chlorobium tepidum

    DEFF Research Database (Denmark)

    Li, Hui; Frigaard, Niels-Ulrik; Bryant, Donald A

    2006-01-01

    type and mutants lacking a single chlorosome protein were cross-linked with the zero-length cross-linker 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and analyzed by gel electrophoresis. Similar cross-linking products were observed when the time and temperature were varied or when EDC...... was replaced with glutaraldehyde. Specific interactions between chlorosome proteins in cross-linked products were identified by immunoblotting with polyclonal antibodies raised against recombinant chlorosome proteins. We confirmed these interactions by demonstrating that these products were missing...... in appropriate mutants. Confirming the location of CsmA in the paracrystalline baseplate, cross-linking showed that CsmA forms dimers, trimers, and homomultimers as large as dodecamers and that CsmA directly interacts with the Fenna-Matthews-Olson protein. Cross-linking further suggests that the precursor form...

  15. The Immunodominance Change and Protection of CD4+ T-Cell Responses Elicited by an Envelope Protein Domain III-Based Tetravalent Dengue Vaccine in Mice.

    Directory of Open Access Journals (Sweden)

    Hsin-Wei Chen

    Full Text Available Dengue is the leading cause of mosquito-borne viral infections and no vaccine is available now. Envelope protein domain III (ED3 is the major target for the binding of dengue virus neutralizing antibodies; however, the ED3-specifc T-cell response is less well understood. To investigate the T-cell responses to four serotypes of dengue virus (DENV-1 to 4, we immunized mice using either a tetravalent ED3-based DNA or protein vaccine, or combined both as a DNA prime-protein boost strategy (prime-boost. A significant serotype-dependent IFN-γ or IL-4 response was observed in mice immunized with either the DNA or protein vaccine. The IFN-γ response was dominant to DENV-1 to 3, whereas the IL-4 response was dominant to DENV-4. Although the similar IgG titers for the four serotypes were observed in mice immunized with the tetravalent vaccines, the neutralizing antibody titers varied and followed the order of 2 = 3>1>4. Interestingly, the lower IFN-γ response to DENV-4 is attributable to the immunodominance change between two CD4+ T-cell epitopes; one T-cell epitope located at E349-363 of DENV-1 to 3 was more immunogenic than the DENV-4 epitope E313-327. Despite DENV-4 specific IFN-γ responses were suppressed by immunodominance change, either DENV-4-specific IFN-γ or neutralizing antibody responses were still recalled after DENV-4 challenge and contributed to virus clearance. Immunization with the prime-boost elicited both IFN-γ and neutralizing antibody responses and provided better protection than either DNA or protein immunization. Our findings shed light on how ED3-based tetravalent dengue vaccines sharpen host CD4 T-cell responses and contribute to protection against dengue virus.

  16. Geraniin extracted from the rind of Nephelium lappaceum binds to dengue virus type-2 envelope protein and inhibits early stage of virus replication.

    Science.gov (United States)

    Abdul Ahmad, Siti Aisyah; Palanisamy, Uma D; Tejo, Bimo A; Chew, Miaw Fang; Tham, Hong Wai; Syed Hassan, Sharifah

    2017-11-21

    The rapid rise and spread in dengue cases, together with the unavailability of safe vaccines and effective antiviral drugs, warrant the need to discover and develop novel anti-dengue treatments. In this study the antiviral activity of geraniin, extracted from the rind of Nephelium lappaceum, against dengue virus type-2 (DENV-2) was investigated. Geraniin was prepared from Nephelium lappaceum rind by reverse phase C-18 column chromatography. Cytotoxicity of geraniin towards Vero cells was evaluated using MTT assay while IC 50 value was determined by plaque reduction assay. The mode-of-action of geraniin was characterized using the virucidal, attachment, penetration and the time-of-addition assays'. Docking experiments with geraniin molecule and the DENV envelope (E) protein was also performed. Finally, recombinant E Domain III (rE-DIII) protein was produced to physiologically test the binding of geraniin to DENV-2 E-DIII protein, through ELISA competitive binding assay. Cytotoxicity assay confirmed that geraniin was not toxic to Vero cells, even at the highest concentration tested. The compound exhibited DENV-2 plaque formation inhibition, with an IC 50 of 1.75 μM. We further revealed that geraniin reduced viral infectivity and inhibited DENV-2 from attaching to the cells but had little effect on its penetration. Geraniin was observed to be most effective when added at the early stage of DENV-2 infection. Docking experiments showed that geraniin binds to DENV E protein, specifically at the DIII region, while the ELISA competitive binding assay confirmed geraniin's interaction with rE-DIII with high affinity. Geraniin from the rind of Nephelium lappaceum has antiviral activity against DENV-2. It is postulated that the compound inhibits viral attachment by binding to the E-DIII protein and interferes with the initial cell-virus interaction. Our results demonstrate that geraniin has the potential to be developed into an effective antiviral treatment, particularly for

  17. Computational analysis of perturbations in the post-fusion Dengue virus envelope protein highlights known epitopes and conserved residues in the Zika virus [version 2; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    2016-09-01

    Full Text Available The dramatic transformation of the Zika virus (ZIKV from a relatively unknown virus to a pathogen generating global-wide panic has exposed the dearth of detailed knowledge about this virus. Decades of research in the related Dengue virus (DENV, finally culminating in a vaccine registered for use in endemic regions (CYD-TDV in three countries, provides key insights in developing strategies for tackling ZIKV, which has caused global panic to microcephaly and Guillain-Barre Syndrome. Dengue virus (DENV, a member of the family Flaviviridae, the causal agent of the self-limiting Dengue fever and the potentially fatal hemorrhagic fever/dengue shock syndrome, has been a scourge in tropical countries for many centuries. The recently solved structure of mature ZIKV (PDB ID:5IRE has provided key insights into the structure of the envelope (E and membrane (M proteins, the primary target of neutralizing antibodies. The previously established MEPP methodology compares two conformations of the same protein and identifies residues with significant spatial and electrostatic perturbations. In the current work, MEPP analyzed the pre-and post-fusion DENV type 2 envelope (E protein, and identified several known epitopes (His317, Tyr299, Glu26, Arg188, etc. (MEPPitope. These residues are overwhelmingly conserved in ZIKV and all DENV serotypes, and also enumerates residue pairs that undergo significant polarity reversal. Characterization of α-helices in E-proteins show that α1 is not conserved in the sequence space of ZIKV and DENV. Furthermore, perturbation of α1 in the post-fusion DENV structure includes a known epitope Asp215, a residue absent in the pre-fusion α1. A cationic β-sheet in the GAG-binding domain that is stereochemically equivalent in ZIKV and all DENV serotypes is also highlighted due to a residue pair (Arg286-Arg288 that has a significant electrostatic polarity reversal upon fusion. Finally, two highly conserved residues (Thr32 and Thr40, with

  18. Computational analysis of perturbations in the post-fusion Dengue virus envelope protein highlights known epitopes and conserved residues in the Zika virus.

    Science.gov (United States)

    Chakraborty, Sandeep

    2016-01-01

    The dramatic transformation of the Zika virus (ZIKV) from a relatively unknown virus to a pathogen generating global-wide panic has exposed the dearth of detailed knowledge about this virus. Decades of research in the related Dengue virus (DENV), finally culminating in a vaccine registered for use in endemic regions (CYD-TDV) in three countries, provides key insights in developing strategies for tackling ZIKV, which has caused global panic to microcephaly and Guillain-Barre Syndrome. Dengue virus (DENV), a member of the family Flaviviridae, the causal agent of the self-limiting Dengue fever and the potentially fatal hemorrhagic fever/dengue shock syndrome, has been a scourge in tropical countries for many centuries. The recently solved structure of mature ZIKV (PDB ID:5IRE) has provided key insights into the structure of the envelope (E) and membrane (M) proteins, the primary target of neutralizing antibodies. The previously established MEPP methodology compares two conformations of the same protein and identifies residues with significant spatial and electrostatic perturbations. In the current work, MEPP analyzed the pre-and post-fusion DENV type 2 envelope (E) protein, and identified several known epitopes (His317, Tyr299, Glu26, Arg188, etc.) (MEPPitope). These residues are overwhelmingly conserved in ZIKV and all DENV serotypes, and also enumerates residue pairs that undergo significant polarity reversal. Characterization of α-helices in E-proteins show that α1 is not conserved in the sequence space of ZIKV and DENV. Furthermore, perturbation of α1 in the post-fusion DENV structure includes a known epitope Asp215, a residue absent in the pre-fusion α1. A cationic β-sheet in the GAG-binding domain that is stereochemically equivalent in ZIKV and all DENV serotypes is also highlighted due to a residue pair (Arg286-Arg288) that has a significant electrostatic polarity reversal upon fusion. Finally, two highly conserved residues (Thr32 and Thr40), with little

  19. Induction of antigen-specific immune responses in mice by recombinant baculovirus expressing premembrane and envelope proteins of West Nile virus

    Directory of Open Access Journals (Sweden)

    Zhu Bibo

    2012-07-01

    Full Text Available Abstract Background West Nile Virus (WNV is an emerging arthropod-born flavivirus with increasing distribution worldwide that is responsible for a large proportion of viral encephalitis in humans and horses. Given that there are no effective antiviral drugs available for treatment of the disease, efforts have been directed to develop vaccines to prevent WNV infection. Recently baculovirus has emerged as a novel and attractive gene delivery vehicle for mammalian cells. Results In the present study, recombinant baculoviruses expressing WNV premembrane (prM and envelope (E proteins under the cytomegalovirus (CMV promoter with or without vesicular stomatitis virus glycoprotein (VSV/G were constructed. The recombinant baculoviruses designated Bac-G-prM/E and Bac-prM/E, efficiently express E protein in mammalian cells. Intramuscular injection of the two recombinant baculoviruses (at doses of 108 or 109 PFU/mouse induced the production of WNV-specific antibodies, neutralizing antibodies as well as gamma interferon (IFN-γ in a dose-dependent pattern. Interestingly, the recombinant baculovirus Bac-G-prM/E was found to be a more efficient immunogen than Bac-prM/E to elicit a robust immune response upon intramuscular injection. In addition, inoculation of baculovirus resulted in the secretion of inflammatory cytokines, such as TNF-α, IL-2 and IL-6. Conclusions These recombinant baculoviruses are capable of eliciting robust humoral and cellular immune responses in mice, and may be considered as novel vaccine candidates for West Nile Virus.

  20. Multi-walled carbon nanotubes functionalized with recombinant Dengue virus 3 envelope proteins induce significant and specific immune responses in mice.

    Science.gov (United States)

    Versiani, Alice F; Astigarraga, Ruiz G; Rocha, Eliseu S O; Barboza, Ana Paula M; Kroon, Erna G; Rachid, Milene A; Souza, Daniele G; Ladeira, Luiz O; Barbosa-Stancioli, Edel F; Jorio, Ado; Da Fonseca, Flávio G

    2017-04-04

    Dengue is the most prevalent arthropod-borne viral disease in the world. In this article we present results on the development, characterization and immunogenic evaluation of an alternative vaccine candidate against Dengue. The MWNT-DENV3E nanoconjugate was developed by covalent functionalization of carboxylated multi-walled carbon nanotubes (MWNT) with recombinant dengue envelope (DENV3E) proteins. The recombinant antigens were bound to the MWNT using a diimide-activated amidation process and the immunogen was characterized by TEM, AFM and Raman Spectroscopy. Furthermore, the immunogenicity of this vaccine candidate was evaluated in a murine model. Immunization with MWNT-DENV3E induced comparable IgG responses in relation to the immunization with non-conjugated proteins; however, the inoculation of the nanoconjugate into mice generated higher titers of neutralizing antibodies. Cell-mediated responses were also evaluated, and higher dengue-specific splenocyte proliferation was observed in cell cultures derived from mice immunized with MWNT-DENV3E when compared to animals immunized with the non-conjugated DENV3E. Despite the recent licensure of the CYD-TDV dengue vaccine in some countries, results from the vaccine's phase III trial have cast doubts about its overall efficacy and global applicability. While questions about the effectiveness of the CYD-TDV vaccine still lingers, it is wise to keep at hand an array of vaccine candidates, including alternative non-classical approaches like the one presented here.

  1. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  2. Identification of Estrogen-responsive Vitelline Envelope Protein Fragments from Rainbow Trout (Oncorhynchus mykiss) Plasma Using Mass Spectrometry

    Science.gov (United States)

    Plasma protein biomarkers associated with exposure of rainbow trout (Oncorhynchus mykiss) to 17β-estradiol were isolated and identified using novel sample preparation techniques and state-of-the-art mass spectrometry and bioinformatics approaches. Juvenile male and female trout ...

  3. An N-terminally truncated envelope protein encoded by a human endogenous retrovirus W locus on chromosome Xq22.3

    Directory of Open Access Journals (Sweden)

    Roebke Christina

    2010-08-01

    Full Text Available Abstract Background We previously showed that the envelope (env sequence of a human endogenous retrovirus (HERV-W locus on chromosome Xq22.3 is transcribed in human peripheral blood mononuclear cells. The env open reading frame (ORF of this locus is interrupted by a premature stop at codon 39, but otherwise harbors a long ORF for an N-terminally truncated 475 amino acid Env protein, starting at an in-frame ATG at codon 68. We set out to characterize the protein encoded by that ORF. Results Transient expression of the 475 amino acid Xq22.3 HERV-W env ORF produced an N-terminally truncated HERV-W Env protein, as detected by the monoclonal anti-HERV-W Env antibodies 6A2B2 and 13H5A5. Remarkably, reversion of the stop at codon 39 in Xq22.3 HERV-W env reconstituted a full-length HERV-W Xq22.3 Env protein. Similar to the full-length HERV-W Env protein Syncytin-1, reconstituted full-length Xq22.3 HERV-W Env is glycosylated, forms oligomers, and is expressed at the cell surface. In contrast, Xq22.3 HERV-W Env is unglycosylated, does not form oligomers, and is located intracellularly, probably due to lack of a signal peptide. Finally, we reconfirm by immunohistochemistry that monoclonal antibody 6A2B2 detects an antigen expressed in placenta and multiple sclerosis brain lesions. Conclusions A partially defective HERV-W env gene located on chromosome Xq22.3, which we propose to designate ERVWE2, has retained coding capacity and can produce ex vivo an N-terminally truncated Env protein, named N-Trenv. Detection of an antigen by 6A2B2 in placenta and multiple sclerosis lesions opens the possibility that N-Trenv could be expressed in vivo. More generally, our findings are compatible with the idea that defective HERV elements may be capable of producing incomplete HERV proteins that, speculatively, may exert functions in human physiology or pathology.

  4. Pichia pastoris-expressed dengue 2 envelope forms virus-like particles without pre-membrane protein and induces high titer neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Shailendra Mani

    Full Text Available Dengue is a mosquito-borne viral disease with a global prevalence. It is caused by four closely-related dengue viruses (DENVs 1-4. A dengue vaccine that can protect against all four viruses is an unmet public health need. Live attenuated vaccine development efforts have encountered unexpected interactions between the vaccine viruses, raising safety concerns. This has emphasized the need to explore non-replicating dengue vaccine options. Virus-like particles (VLPs which can elicit robust immunity in the absence of infection offer potential promise for the development of non-replicating dengue vaccine alternatives. We have used the methylotrophic yeast Pichia pastoris to develop DENV envelope (E protein-based VLPs. We designed a synthetic codon-optimized gene, encoding the N-terminal 395 amino acid residues of the DENV-2 E protein. It also included 5' pre-membrane-derived signal peptide-encoding sequences to ensure proper translational processing, and 3' 6× His tag-encoding sequences to facilitate purification of the expressed protein. This gene was integrated into the genome of P. pastoris host and expressed under the alcohol oxidase 1 promoter by methanol induction. Recombinant DENV-2 protein, which was present in the insoluble membrane fraction, was extracted and purified using Ni(2+-affinity chromatography under denaturing conditions. Amino terminal sequencing and detection of glycosylation indicated that DENV-2 E had undergone proper post-translational processing. Electron microscopy revealed the presence of discrete VLPs in the purified protein preparation after dialysis. The E protein present in these VLPs was recognized by two different conformation-sensitive monoclonal antibodies. Low doses of DENV-2 E VLPs formulated in alum were immunogenic in inbred and outbred mice eliciting virus neutralizing titers >1,1200 in flow cytometry based assays and protected AG129 mice against lethal challenge (p<0.05. The formation of immunogenic DENV-2 E

  5. Envelope Protein Mutations L107F and E138K Are Important for Neurovirulence Attenuation for Japanese Encephalitis Virus SA14-14-2 Strain.

    Science.gov (United States)

    Yang, Jian; Yang, Huiqiang; Li, Zhushi; Wang, Wei; Lin, Hua; Liu, Lina; Ni, Qianzhi; Liu, Xinyu; Zeng, Xianwu; Wu, Yonglin; Li, Yuhua

    2017-01-21

    The attenuated Japanese encephalitis virus (JEV) strain SA14-14-2 has been successfully utilized to prevent JEV infection; however, the attenuation determinants have not been fully elucidated. The envelope (E) protein of the attenuated JEV SA14-14-2 strain differs from that of the virulent parental SA14 strain at eight amino acid positions (E107, E138, E176, E177, E264, E279, E315, and E439). Here, we investigated the SA14-14-2-attenuation determinants by mutating E107, E138, E176, E177, and E279 in SA14-14-2 to their status in the parental virulent strain and tested the replication capacity, neurovirulence, neuroinvasiveness, and mortality associated with the mutated viruses in mice, as compared with those of JEV SA14-14-2 and SA14. Our findings indicated that revertant mutations at the E138 or E107 position significantly increased SA14-14-2 virulence, whereas other revertant mutations exhibited significant increases in neurovirulence only when combined with E138, E107, and other mutations. Revertant mutations at all eight positions in the E protein resulted in the highest degree of SA14-14-2 virulence, although this was still lower than that observed in SA14. These results demonstrated the critical role of the viral E protein in controlling JEV virulence and identified the amino acids at the E107 and E138 positions as the key determinants of SA14-14-2 neurovirulence.

  6. [Differences in the spatial structure of an envelope protein from tobacco mosaic virus and its mutant, detected by tritium planigraphy].

    Science.gov (United States)

    Lukashina, E V; Badun, G A; Fedoseev, V M; Fedorova, N V; Ksenofontov, A L; Baratova, L A; Dobrov, E N

    2001-01-01

    Mutant ts21-66 of the tobacco mosaic virus (TMV) differs from the wild-type TMV-U1 by two mutations (Ile-21-->Thr and Asp-66-->Gly) in the coat protein (CP) gene and in symptoms produced in infected N' plants. The CP structure in TMV-U1 and ts21-66 virions was probed by tritium planigraphy. Compared with the wild-type CP, labeling of the N-terminal region of mutant CP was half as high and suggested its greater shielding. A role of this CP region in virus interactions with the N' resistance system is discussed.

  7. An epitope conserved in orthopoxvirus A13 envelope protein is the target of neutralizing and protective antibodies.

    Science.gov (United States)

    Xu, Chungui; Meng, Xiangzhi; Yan, Bo; Crotty, Shane; Deng, Junpeng; Xiang, Yan

    2011-09-15

    Primary immunization of humans with smallpox vaccine (live vaccinia virus (VACV)) consistently elicits antibody responses to six VACV virion membrane proteins, including A13. However, whether anti-A13 antibody contributes to immune protection against orthopoxviruses was unknown. Here, we isolated a murine monoclonal antibody (mAb) against A13 from a mouse that had been infected with VACV. The anti-A13 mAb bound to recombinant A13 protein with an affinity of 3.4nM and neutralized VACV mature virions. Passive immunization of mice with the anti-A13 mAb protected against intranasal VACV infection. The epitope of the anti-A13 mAb was mapped to a 10-amino acid sequence conserved in all orthopoxviruses, including viriola virus and monkeypox virus, suggesting that anti-A13 antibodies elicited by smallpox vaccine might contribute to immune protection against orthopoxviruses. In addition, our data demonstrates that anti-A13 mAbs are effective for treating orthopoxvirus infection. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. The HIV-1 envelope protein gp120 is captured and displayed for B cell recognition by SIGN-R1(+) lymph node macrophages.

    Science.gov (United States)

    Park, Chung; Arthos, James; Cicala, Claudia; Kehrl, John H

    2015-08-10

    The HIV-1 envelope protein gp120 is both the target of neutralizing antibodies and a major focus of vaccine efforts; however how it is delivered to B cells to elicit an antibody response is unknown. Here, we show that following local gp120 injection lymph node (LN) SIGN-R1(+) sinus macrophages located in interfollicular pockets and underlying SIGN-R1(+) macrophages form a cellular network that rapidly captures gp120 from the afferent lymph. In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells. Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells. The gp120 specific, but not the control B cells repetitively extracted gp120 from the network cells. Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells.

  9. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion.

    Science.gov (United States)

    Roehrig, John T; Butrapet, Siritorn; Liss, Nathan M; Bennett, Susan L; Luy, Betty E; Childers, Thomas; Boroughs, Karen L; Stovall, Janae L; Calvert, Amanda E; Blair, Carol D; Huang, Claire Y-H

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. Published by Elsevier Inc.

  10. Molecular Determinants of Dengue Virus 2 Envelope Protein Important for Virus Entry in FcγRIIA-Mediated Antibody-Dependent Enhancement of Infection

    Science.gov (United States)

    Chotiwan, Nunya; Roehrig, John T.; Schlesinger, Jacob J.; Blair, Carol D.; Huang, Claire Y.-H.

    2015-01-01

    Antibody-dependent enhancement (ADE) of infection may cause severe illness in patients suffering a secondary infection by a heterologous dengue virus (DENV) serotype. During ADE of infection, cross-reactive non- or poorly-neutralizing antibodies form infectious virus-Ab complexes with the newly infecting serotype and enhance virus infection by binding to the Fcγ receptors (FcγR) on FcγR-bearing cells. In this study, we determined that molecular determinants of DENV2 envelope protein critical for virus entry during non-ADE infection are also required for ADE infection mediated by FcγRIIA, and binding of virus-Ab complexes with FcγRIIA alone is not sufficient for ADE of infection. The FcγRIIA mainly plays an auxiliary role in concentrating the virus-Ab complex to the cell surface, and other primary cellular receptors are required for virus entry. Understanding the viral entry pathway in ADE of DENV infection will greatly facilitate rational designs of anti-viral therapeutics against severe dengue disease associated with ADE. PMID:24889243

  11. The HIV-1 envelope protein gp120 is captured and displayed for B cell recognition by SIGN-R1+ lymph node macrophages

    Science.gov (United States)

    Park, Chung; Arthos, James; Cicala, Claudia; Kehrl, John H

    2015-01-01

    The HIV-1 envelope protein gp120 is both the target of neutralizing antibodies and a major focus of vaccine efforts; however how it is delivered to B cells to elicit an antibody response is unknown. Here, we show that following local gp120 injection lymph node (LN) SIGN-R1+ sinus macrophages located in interfollicular pockets and underlying SIGN-R1+ macrophages form a cellular network that rapidly captures gp120 from the afferent lymph. In contrast, two other antigens, phycoerythrin and hen egg lysozyme, were not captured by these cells. Intravital imaging of mouse LNs revealed persistent, but transient interactions between gp120 bearing interfollicular network cells and both trafficking and LN follicle resident gp120 specific B cells. The gp120 specific, but not the control B cells repetitively extracted gp120 from the network cells. Our findings reveal a specialized LN antigen delivery system poised to deliver gp120 and likely other pathogen derived glycoproteins to B cells. DOI: http://dx.doi.org/10.7554/eLife.06467.001 PMID:26258881

  12. The use of aqueous two-phase systems to concentrate and purify bovine leukemia virus outer envelope protein gp51.

    Science.gov (United States)

    Hammar, L; Merza, M; Malm, K; Eriksson, S; Morein, B

    1989-06-01

    Enzootic bovine leucosis is a chronic lymphoproliferative disease of cattle. The causative agent, bovine leukemia virus (BLV), is related to the human retroviruses HTLV-I and -II. The external env-protein of BLV, a glycoprotein of 51 kDa, carries neutralizing epitopes and should be an essential component in a vaccine against the virus. Problems have been encountered with the concentration and purification of intact virions of BLV and other retroviruses. During centrifugation procedures the external env-proteins are to a great extent detached and consequently poorly recovered with the virion particles. Therefore, other methods are sought to obtain a high yield of the external glycoproteins. The use of two-phase systems based on water soluble polymers is described for the extraction of BLV-gp51 from culture medium. Several polymer systems were tested and the results showed that some were attractive for large scale application. The classical combination dextran-polyethylene glycol gave promising results; a partition coefficient of about 0.02 was obtained for the distribution of the gp51 between the top and combined inter- and bottom phases. In a single extraction step it was possible to obtain 45% of the glycoprotein in a small volume bottom phase and at the same time about 15-fold purified. That should be compared with a recovery of less than 20% with the conventional centrifugation procedures. It is concluded that extraction in phase systems based on water soluble polymers is a methodology well suited for the concentration and purification of BLV-gp51.

  13. GB virus C envelope protein E2 inhibits T cell receptor induced IL-2 production and alters IL-2 signaling pathways

    Science.gov (United States)

    Bhattarai, Nirjal; McLinden, James H.; Xiang, Jinhua; Kaufman, Thomas M.; Stapleton, Jack T.

    2012-01-01

    GB virus type C (GBV-C) viremia is associated with reduced CD4+ T cell expansion following Interleukin 2 (IL-2) therapy and with a reduction in T cell activation in HIV-infected individuals. Mechanism(s) by which GBV-C might alter T-cell activation or IL-2 signaling have not been studied. Here, we assess IL-2 release, IL-2 receptor (IL-2R) expression, IL-2 signaling, and cell proliferation in Tet-off Jurkat cells expressing the GBV-C envelope glycoprotein (E2) following activation through the T cell receptor (TCR). TCR activation was induced by incubation in anti-CD3/CD28 antibodies. IL-2 release was measured by ELISA, STAT5 phosphorylation was assessed by immunoblot, and IL-2Rα (CD25) expression and cell proliferation were determined by flow cytometry. IL-2 and IL-2Rα steady-state mRNA levels were measured by real-time PCR. GBV-C E2 expression significantly inhibited IL-2 release, CD25 expression, STAT5 phosphorylation and cellular proliferation in Jurkat cells following activation through the TCR compared to control cell lines. Reducing E2 expression by doxycycline reversed the inhibitory effects observed in the E2-expressing cells. The N-terminal 219 a.a of E2 was sufficient to inhibit IL-2 signaling. Addition of purified recombinant GBV-C E2 protein to primary human CD4+ and CD8+ T cells inhibited TCR activation-induced IL-2 release and upregulation of IL-2Rα expression. These data provide evidence that the GBV-C E2 protein may contribute to the block in CD4+ T cell expansion following IL-2 therapy in HIV-infected individuals. Furthermore, the effects of GBV-C on IL-2 and IL-2 signaling pathways may contribute to the reduction in chronic immune activation observed in GBV-C/HIV co-infected individuals. PMID:22844114

  14. Analysis of Epitopes on Dengue Virus Envelope Protein Recognized by Monoclonal Antibodies and Polyclonal Human Sera by a High Throughput Assay

    Science.gov (United States)

    Lin, Hong-En; Tsai, Wen-Yang; Liu, I-Ju; Li, Pi-Chun; Liao, Mei-Ying; Tsai, Jih-Jin; Wu, Yi-Chieh; Lai, Chih-Yun; Lu, Chih-Hsuan; Huang, Jyh-Hsiung; Chang, Gwong-Jen; Wu, Han-Chung; Wang, Wei-Kung

    2012-01-01

    Background The envelope (E) protein of dengue virus (DENV) is the major target of neutralizing antibodies and vaccine development. While previous studies on domain III or domain I/II alone have reported several epitopes of monoclonal antibodies (mAbs) against DENV E protein, the possibility of interdomain epitopes and the relationship between epitopes and neutralizing potency remain largely unexplored. Methodology/Principal Findings We developed a dot blot assay by using 67 alanine mutants of predicted surface-exposed E residues as a systematic approach to identify epitopes recognized by mAbs and polyclonal sera, and confirmed our findings using a capture-ELISA assay. Of the 12 mouse mAbs tested, three recognized a novel epitope involving residues (Q211, D215, P217) at the central interface of domain II, and three recognized residues at both domain III and the lateral ridge of domain II, suggesting a more frequent presence of interdomain epitopes than previously appreciated. Compared with mAbs generated by traditional protocols, the potent neutralizing mAbs generated by a new protocol recognized multiple residues in A strand or residues in C strand/CC′ loop of DENV2 and DENV1, and multiple residues in BC loop and residues in DE loop, EF loop/F strand or G strand of DENV1. The predominant epitopes of anti-E antibodies in polyclonal sera were found to include both fusion loop and non-fusion residues in the same or adjacent monomer. Conclusions/Significance Our analyses have implications for epitope-specific diagnostics and epitope-based dengue vaccines. This high throughput method has tremendous application for mapping both intra and interdomain epitopes recognized by human mAbs and polyclonal sera, which would further our understanding of humoral immune responses to DENV at the epitope level. PMID:22235356

  15. Induction of polyploidy by nuclear fusion mechanism upon decreased expression of the nuclear envelope protein LAP2β in the human osteosarcoma cell line U2OS.

    Science.gov (United States)

    Ben-Shoshan, Shirley Oren; Simon, Amos J; Jacob-Hirsch, Jasmine; Shaklai, Sigal; Paz-Yaacov, Nurit; Amariglio, Ninette; Rechavi, Gideon; Trakhtenbrot, Luba

    2014-01-28

    Polyploidy has been recognized for many years as an important hallmark of cancer cells. Polyploid cells can arise through cell fusion, endoreplication and abortive cell cycle. The inner nuclear membrane protein LAP2β plays key roles in nuclear envelope breakdown and reassembly during mitosis, initiation of replication and transcriptional repression. Here we studied the function of LAP2β in the maintenance of cell ploidy state, a role which has not yet been assigned to this protein. By knocking down the expression of LAP2β, using both viral and non-viral RNAi approaches in osteosarcoma derived U2OS cells, we detected enlarged nuclear size, nearly doubling of DNA content and chromosomal duplications, as analyzed by fluorescent in situ hybridization and spectral karyotyping methodologies. Spectral karyotyping analyses revealed that near-hexaploid karyotypes of LAP2β knocked down cells consisted of not only seven duplicated chromosomal markers, as could be anticipated by genome duplication mechanism, but also of four single chromosomal markers. Furthermore, spectral karyotyping analysis revealed that both of two near-triploid U2OS sub-clones contained the seven markers that were duplicated in LAP2β knocked down cells, whereas the four single chromosomal markers were detected only in one of them. Gene expression profiling of LAP2β knocked down cells revealed that up to a third of the genes exhibiting significant changes in their expression are involved in cancer progression. Our results suggest that nuclear fusion mechanism underlies the polyploidization induction upon LAP2β reduced expression. Our study implies on a novel role of LAP2β in the maintenance of cell ploidy status. LAP2β depleted U2OS cells can serve as a model to investigate polyploidy and aneuploidy formation by nuclear fusion mechanism and its involvement in cancerogenesis.

  16. Plant-produced Zika virus envelope protein elicits neutralizing immune responses that correlate with protective immunity against Zika virus in mice.

    Science.gov (United States)

    Yang, Ming; Sun, Haiyan; Lai, Huafang; Hurtado, Jonathan; Chen, Qiang

    2017-07-15

    The global Zika virus (ZIKV) outbreak and its link to foetal and newborn microcephaly and severe neurological complications in adults call for the urgent development of ZIKV vaccines. In response, we developed a subunit vaccine based on the ZIKV envelope (E) protein and investigated its immunogenicity in mice. Transient expression of ZIKV E (zE) resulted in its rapid accumulation in leaves of Nicotiana benthamiana plants. Biochemical analysis revealed that plant-produced ZIKV E (PzE) exhibited specific binding to a panel of monoclonal antibodies that recognize various zE conformational epitopes. Furthermore, PzE can be purified to >90% homogeneity with a one-step Ni2+ affinity chromatography process. PzE are found to be highly immunogenic, as two doses of PzE elicited both potent zE-specific antibody and cellular immune responses in mice. The delivery of PzE with alum induced a mixed Th1/Th2 immune response, as the antigen-specific IgG isotypes were a mixture of high levels of IgG1/IgG2c and splenocyte cultures from immunized mice secreted significant levels of IFN-gamma, IL-4 and IL-6. Most importantly, the titres of zE-specific and neutralizing antibodies exceeded the threshold that correlates with protective immunity against multiple strains of ZIKV. Thus, our results demonstrated the feasibility of plant-produced ZIKV protein antigen as effective, safe and affordable vaccines against ZIKV. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  17. Novel function of the endoplasmic reticulum degradation-enhancing α-mannosidase-like proteins in the human hepatitis B virus life cycle, mediated by the middle envelope protein.

    Science.gov (United States)

    Lazar, Catalin; Uta, Mihaela; Petrescu, Stefana Maria; Branza-Nichita, Norica

    2017-02-01

    Cells replicating the human hepatitis B virus (HBV) express high levels of degradation-enhancing α-mannosidase-like proteins (EDEMs), a family of proteins involved in the endoplasmic reticulum associated degradation, one of the pathways activated during the unfolded protein response. Owing to their α-1,2 mannosidase activity, the EDEM1-3 proteins are able to process the N-linked glycans of misfolded or incompletely folded proteins, providing the recognition signal for their subsequent degradation. The HBV small (S), medium (M), and large (L) surface proteins bear an N-linked glycosylation site in the common S domain that is partially occupied in all proteins. The M protein contains an additional site in its preS2 domain, which is always functional. Here, we report that these oligosaccharides are processed by EDEMs, more efficiently by EDEM3, which induces degradation of L and S proteins, accompanied by a reduction of subviral particles production. In striking contrast, M not only is spared from degradation but its trafficking is also accelerated leading to an improved secretion. This unusual behavior of the M protein requires strictly the mannose trimming of the preS2 N-linked glycan. Furthermore, we show that HBV secretion is significantly inhibited under strong endoplasmic reticulum stress conditions when M expression is prevented by mutagenesis of the viral genome. These observations unfold unique properties of the M protein in the HBV life cycle during unfolded protein response and point to alternative mechanisms employed by EDEMs to alleviate this stress in case of necessity by promoting glycoprotein trafficking rather than degradation. © 2016 John Wiley & Sons Ltd.

  18. The Rcs stress response and accessory envelope proteins are required for de novo generation of cell shape in Escherichia coli.

    Science.gov (United States)

    Ranjit, Dev K; Young, Kevin D

    2013-06-01

    Interactions with immune responses or exposure to certain antibiotics can remove the peptidoglycan wall of many Gram-negative bacteria. Though the spheroplasts thus created usually lyse, some may survive by resynthesizing their walls and shapes. Normally, bacterial morphology is generated by synthetic complexes directed by FtsZ and MreBCD or their homologues, but whether these classic systems can recreate morphology in the absence of a preexisting template is unknown. To address this question, we treated Escherichia coli with lysozyme to remove the peptidoglycan wall while leaving intact the inner and outer membranes and periplasm. The resulting lysozyme-induced (LI) spheroplasts recovered a rod shape after four to six generations. Recovery proceeded via a series of cell divisions that produced misshapen and branched intermediates before later progeny assumed a normal rod shape. Importantly, mutants defective in mounting the Rcs stress response and those lacking penicillin binding protein 1B (PBP1B) or LpoB could not divide or recover their cell shape but instead enlarged until they lysed. LI spheroplasts from mutants lacking the Lpp lipoprotein or PBP6 produced spherical daughter cells that did not recover a normal rod shape or that did so only after a significant delay. Thus, to regenerate normal morphology de novo, E. coli must supplement the classic FtsZ- and MreBCD-directed cell wall systems with activities that are otherwise dispensable for growth under normal laboratory conditions. The existence of these auxiliary mechanisms implies that they may be required for survival in natural environments, where bacterial walls can be damaged extensively or removed altogether.

  19. Induction of HIV neutralizing antibodies against the MPER of the HIV envelope protein by HA/gp41 chimeric protein-based DNA and VLP vaccines

    National Research Council Canada - National Science Library

    Ye, Ling; Wen, Zhiyuan; Dong, Ke; Wang, Xi; Bu, Zhigao; Zhang, Huizhong; Compans, Richard W; Yang, Chinglai

    2011-01-01

    .... We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies...

  20. Computer-based comparison of structural features of envelope protein of Alkhurma hemorrhagic fever virus with the homologous proteins of two closest viruses.

    Science.gov (United States)

    Mohabatkar, Hassan

    2011-06-01

    The aim of this study was prediction of epitopes and medically important structural properties of protein E of Alkhurma hemorrhagic fever virus (AHFV) and comparing these features with two closely relates viruses, i.e. Kyasanur Forest disease virus (KFDV) and Tick-borne encephalitis virus (TBEV) by bioinformatics tools. Prediction of evolutionary distance, localization, sequence of signal peptides, C, N O glycosylation sites, transmembrane helices (TMHs), cysteine bond positions and B cell and T cell epitopes of E proteins were performed. 2D-MH, Virus-PLoc, Signal-CF, EnsembleGly, MemBrain, DiANNA, BCPREDS and MHCPred servers were applied for the prediction. According to the results, the evolutionary distance of E protein of AHFV and two other viruses was almost equal. In all three proteins of study, residues 1-35 were predicted as signal sequences and one asparagine was predicted to be glycosylated. Results of prediction of transmembrane helices showed one TMH at position 444-467 and the other one at position 476-490. Twelve cysteines were potentially involved to form six disulfide bridges in the proteins. Four parts were predicted as B cell epitopes in E protein of AHFV. One epitope was conserved between three proteins of study. The only conserved major histocompatibility complex (MHC) binding epitope between three viruses was for DRB0401 allele. As there are not much experimental data available about AHFV, computer-aided study and comparison of E protein of this virus with two closely related flaviviruses can help in better understanding of medical properties of the virus.

  1. Virosomes of hepatitis B virus envelope L proteins containing doxorubicin: synergistic enhancement of human liver-specific antitumor growth activity by radiotherapy.

    Science.gov (United States)

    Liu, Qiushi; Jung, Joohee; Somiya, Masaharu; Iijima, Masumi; Yoshimoto, Nobuo; Niimi, Tomoaki; Maturana, Andrés D; Shin, Seol Hwa; Jeong, Seong-Yun; Choi, Eun Kyung; Kuroda, Shun'ichi

    2015-01-01

    Bionanocapsules (BNCs) are hollow nanoparticles consisting of hepatitis B virus (HBV) envelope L proteins and have been shown to deliver drugs and genes specifically to human hepatic tissues by utilizing HBV-derived infection machinery. The complex of BNCs with liposomes (LPs), the BNC-LP complexes (a LP surrounded by BNCs in a rugged spherical form), could also become active targeting nanocarriers by the BNC function. In this study, under acidic conditions and high temperature, BNCs were found to fully fuse with LPs (smooth-surfaced spherical form), deploying L proteins with a membrane topology similar to that of BNCs (ie, virosomes displaying L proteins). Doxorubicin (DOX) was efficiently encapsulated via the remote loading method at 14.2%±1.0% of total lipid weight (mean ± SD, n=3), with a capsule size of 118.2±4.7 nm and a ζ-potential of -51.1±1.0 mV (mean ± SD, n=5). When mammalian cells were exposed to the virosomes, the virosomes showed strong cytotoxicity in human hepatic cells (target cells of BNCs), but not in human colon cancer cells (nontarget cells of BNCs), whereas LPs containing DOX and DOXOVES (structurally stabilized PEGylated LPs containing DOX) did not show strong cytotoxicity in either cell type. Furthermore, the virosomes preferentially delivered DOX to the nuclei of human hepatic cells. Xenograft mice harboring either target or nontarget cell-derived tumors were injected twice intravenously with the virosomes containing DOX at a low dose (2.3 mg/kg as DOX, 5 days interval). The growth of target cell-derived tumors was retarded effectively and specifically. Next, the combination of high dose (10.0 mg/kg as DOX, once) with tumor-specific radiotherapy (3 Gy, once after 2 hours) exhibited the most effective antitumor growth activity in mice harboring target cell-derived tumors. These results demonstrated that the HBV-based virosomes containing DOX could be an effective antitumor nanomedicine specific to human hepatic tissues, especially in

  2. Molecular determinants of dengue virus 2 envelope protein important for virus entry in FcγRIIA-mediated antibody-dependent enhancement of infection

    Energy Technology Data Exchange (ETDEWEB)

    Chotiwan, Nunya; Roehrig, John T. [Arboviral Diseases Branch, Division of Vector-Borne Disease, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Schlesinger, Jacob J. [Department of Medicine, University of Rochester, Rochester, NY 14642 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H., E-mail: yxh0@cdc.gov [Arboviral Diseases Branch, Division of Vector-Borne Disease, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2014-05-15

    Antibody-dependent enhancement (ADE) of infection may cause severe illness in patients suffering a secondary infection by a heterologous dengue virus (DENV) serotype. During ADE of infection, cross-reactive non- or poorly-neutralizing antibodies form infectious virus-Ab complexes with the newly infecting serotype and enhance virus infection by binding to the Fcγ receptors (FcγR) on FcγR-bearing cells. In this study, we determined that molecular determinants of DENV2 envelope protein critical for virus entry during non-ADE infection are also required for ADE infection mediated by FcγRIIA, and binding of virus-Ab complexes with FcγRIIA alone is not sufficient for ADE of infection. The FcγRIIA mainly plays an auxiliary role in concentrating the virus–Ab complex to the cell surface, and other primary cellular receptors are required for virus entry. Understanding the viral entry pathway in ADE of DENV infection will greatly facilitate rational designs of anti-viral therapeutics against severe dengue disease associated with ADE. - Highlights: • KKK305/307/310 in DENV2 E-DIII is critical for virus attachment in ADE and non-ADE infection. • Binding of DENV2–Ab complex with FcγRII alone is not sufficient for virus entry in ADE infection. • Other primary receptors were required for DENV2 internalization during FcγRII–mediated ADE. • G104 and L135 of DENV2 E are critical for virus-mediated membrane fusion. • DENV2 virus-mediated membrane fusion is required for both ADE and non-ADE infection.

  3. Effect of Glycosylation on an Immunodominant Region in the V1V2 Variable Domain of the HIV-1 Envelope gp120 Protein.

    Directory of Open Access Journals (Sweden)

    Jianhui Tian

    2016-10-01

    Full Text Available Heavy glycosylation of the envelope (Env surface subunit, gp120, is a key adaptation of HIV-1; however, the precise effects of glycosylation on the folding, conformation and dynamics of this protein are poorly understood. Here we explore the patterns of HIV-1 Env gp120 glycosylation, and particularly the enrichment in glycosylation sites proximal to the disulfide linkages at the base of the surface-exposed variable domains. To dissect the influence of glycans on the conformation these regions, we focused on an antigenic peptide fragment from a disulfide bridge-bounded region spanning the V1 and V2 hyper-variable domains of HIV-1 gp120. We used replica exchange molecular dynamics (MD simulations to investigate how glycosylation influences its conformation and stability. Simulations were performed with and without N-linked glycosylation at two sites that are highly conserved across HIV-1 isolates (N156 and N160; both are contacts for recognition by V1V2-targeted broadly neutralizing antibodies against HIV-1. Glycosylation stabilized the pre-existing conformations of this peptide construct, reduced its propensity to adopt other secondary structures, and provided resistance against thermal unfolding. Simulations performed in the context of the Env trimer also indicated that glycosylation reduces flexibility of the V1V2 region, and provided insight into glycan-glycan interactions in this region. These stabilizing effects were influenced by a combination of factors, including the presence of a disulfide bond between the Cysteines at 131 and 157, which increased the formation of beta-strands. Together, these results provide a mechanism for conservation of disulfide linkage proximal glycosylation adjacent to the variable domains of gp120 and begin to explain how this could be exploited to enhance the immunogenicity of those regions. These studies suggest that glycopeptide immunogens can be designed to stabilize the most relevant Env conformations to

  4. Induction of HIV neutralizing antibodies against the MPER of the HIV envelope protein by HA/gp41 chimeric protein-based DNA and VLP vaccines.

    Science.gov (United States)

    Ye, Ling; Wen, Zhiyuan; Dong, Ke; Wang, Xi; Bu, Zhigao; Zhang, Huizhong; Compans, Richard W; Yang, Chinglai

    2011-01-01

    Several conserved neutralizing epitopes have been identified in the HIV Env protein and among these, the MPER of gp41 has received great attention and is widely recognized as a promising target. However, little success has been achieved in eliciting MPER-specific HIV neutralizing antibodies by a number of different vaccine strategies. We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies. In characterization of the HA/gp41 chimeric protein, we found that by mutating an unpaired Cys residue (Cys-14) in its HA1 subunit to a Ser residue, the modified chimeric protein HA-C14S/gp41 showed increased reactivity to a conformation-sensitive monoclonal antibody against HA and formed more stable trimers in VLPs. On the other hand, HA-C14S/gp41 and HA/gp41 chimeric proteins expressed on the cell surfaces exhibited similar reactivity to monoclonal antibodies 2F5 and 4E10. Immunization of guinea pigs using the HA-C14S/gp41 DNA or VLP vaccines induced antibodies against the HIV gp41 as well as to a peptide corresponding to a segment of MPER at higher levels than immunization by standard HIV VLPs. Further, sera from vaccinated guinea pigs were found to exhibit HIV neutralizing activities. Moreover, sera from guinea pigs vaccinated by HA-C14S/gp41 DNA and VLP vaccines but not the standard HIV VLPs, were found to neutralize HIV pseudovirions containing a SIV-4E10 chimeric Env protein. The virus neutralization could be blocked by a MPER-specific peptide, thus demonstrating induction of MPER-specific HIV neutralizing antibodies by this novel vaccine strategy. These results show that induction of MPER-specific HIV neutralizing antibodies can be achieved through a rationally designed vaccine strategy.

  5. Oxidative stress and protein oxidation in the brain of water drinking and alcohol drinking rats administered the HIV envelope protein, gp120.

    Science.gov (United States)

    Singh, Ashok K; Gupta, Shveta; Jiang, Yin

    2008-03-01

    Possible roles of oxidative stress and protein oxidation on alcohol-induced augmentation of cerebral neuropathy in gp120 administered alcohol preferring rats drinking either pure water (W rats) or a free-choice ethanol and water (E rats) for 90 days. This study showed that peripherally administered gp120 accumulated into the brain, liver, and RBCs samples from water drinking - gp120 administered rats (Wg rats) and ethanol drinking - gp120 administered rats (Eg rats), although gp120 levels in samples from Eg rats were significantly greater than the levels in samples from Wg rats. The brain samples from ethanol drinking-saline administered (EC) and Wg rats exhibited comparable levels of free radicals that were significantly lower than the levels in Eg rats. Peroxiredoxin-I (PrxI) activity in the brain samples exhibited the following pattern: Wg > > WC > EC > Eg. Total protein-carbonyl and carbonylated hippocampal cholinergic neurostimulating peptide precursor protein levels, but not N-acetylaspartate or N-acetyl aspartylglutamate or total protein-thiol levels, paralleled the free radical levels in the brain of all four groups. This suggests PrxI inhibition may be more sensitive indicator of oxidative stress than measuring free radicals or metabolites. As PrxI oxidation in WC, Wg, and EC rats was reversible, while PrxI oxidation in Eg rats was not, we suggest that alcohol drinking and gp120 together hyperoxidized and inactivated PrxI that suppressed free radical neutralization in the brain of Eg rats. In conclusion, chronic alcohol drinking, by carbonylating and hyperoxidizing free radical neutralization proteins, augmented the gp120-induced oxidative stress that may be associated with an increase in severity of the brain neuropathy.

  6. Genetic Diversity of Koala Retroviral Envelopes

    Directory of Open Access Journals (Sweden)

    Wenqin Xu

    2015-03-01

    Full Text Available Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  7. Genetic diversity of koala retroviral envelopes.

    Science.gov (United States)

    Xu, Wenqin; Gorman, Kristen; Santiago, Jan Clement; Kluska, Kristen; Eiden, Maribeth V

    2015-03-17

    Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A) were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  8. Targeting of the retroviral envelope protein SL3-2 towards the human G-Protein coupled receptor hAPJ

    DEFF Research Database (Denmark)

    Pagh, Kristina

    baseret på en murin leukemi virus, SL3-2. Denne virus er valgt, da den kun er i stand til at inficere museceller og derfor vil kunne bruges i senere forsøg med andre organismer, herunder mennesket. Den første metode, der bliver beskrevet, er apelin projektet, hvor vi gennem modificering af det virale...... overflade protein af SL3-2 har indsat en naturlig ligand for et humant protein. Det er apelin receptoren, APJ, som findes på overfladen af forskellige humane celletyper. Gennem de beskrevne forsøg er det lykkedes os at få SL3-2 til at inficere celler via APJ. Det har vist sig, at SL3-2 er en fremragende...... platform til målrettet inficering af celler. Den anden metode er baseret på de resultater vi har opnået med det første forsøg. Her har vi udnyttet det område i SL3-2, som viste sig at være tolerant for ændringer i apelin projektet. Heri har vi indsat det ene af to små peptider. Peptid 1 kan genkendes af et...

  9. Initial preclinical safety of non-replicating human endogenous retrovirus envelope protein-coated baculovirus vector-based vaccines against human papillomavirus.

    Science.gov (United States)

    Han, Su-Eun; Kim, Mi-Gyeong; Lee, Soondong; Cho, Hee-Jeong; Byun, Youngro; Kim, Sujeong; Kim, Young Bong; Choi, Yongseok; Oh, Yu-Kyoung

    2013-12-01

    Human endogenous retrovirus (HERV) envelope protein-coated, baculovirus vector-based HPV 16 L1 (AcHERV-HPV16L1) is a non-replicating recombinant baculoviral vaccine. Here, we report an initial evaluation of the preclinical safety of AcHERV-HPV16L1 vaccine. In an acute toxicity study, a single administration of AcHERV-HPV16L1 DNA vaccine given intramuscularly (i.m.) to mice at a dose of 1 × 10(8) plaque-forming units (PFU) did not cause significant changes in body weight compared with vehicle-treated controls. It did cause a brief increase in the weights of some organs on day 15 post-treatment, but by day 30, all organ weights were not significantly different from those in the vehicle-treated control group. No hematological changes were observed on day 30 post-treatment. In a range-finding toxicity study with three doses of 1 × 10(7) , 2 × 10(7) and 5 × 10(7) PFU once daily for 5 days, the group treated with 5 × 10(7) PFU showed a transient decrease in the body weights from day 5 to day 15 post-treatment, but recovery to the levels similar to those in the vehicle-treated control group by post-treatment day 20. Organ weights were slightly higher for lymph nodes, spleen, thymus and liver after repeated dosing with 5 × 10(7) PFU on day 15, but had normalized by day 30. Moreover, repeated administration of AcHERV-HPV16L1 did not induce myosin-specific autoantibody in serum, and did not cause immune complex deposition or tissue damage at injection sites. Taken together, these results provide preliminary evidence of the preclinical safety of AcHERV-based HPV16L1 DNA vaccines in mice. Copyright © 2012 John Wiley & Sons, Ltd.

  10. Tegument Assembly and Secondary Envelopment of Alphaherpesviruses

    Directory of Open Access Journals (Sweden)

    Danielle J. Owen

    2015-09-01

    Full Text Available Alphaherpesviruses like herpes simplex virus are large DNA viruses characterized by their ability to establish lifelong latent infection in neurons. As for all herpesviruses, alphaherpesvirus virions contain a protein-rich layer called “tegument” that links the DNA-containing capsid to the glycoprotein-studded membrane envelope. Tegument proteins mediate a diverse range of functions during the virus lifecycle, including modulation of the host-cell environment immediately after entry, transport of virus capsids to the nucleus during infection, and wrapping of cytoplasmic capsids with membranes (secondary envelopment during virion assembly. Eleven tegument proteins that are conserved across alphaherpesviruses have been implicated in the formation of the tegument layer or in secondary envelopment. Tegument is assembled via a dense network of interactions between tegument proteins, with the redundancy of these interactions making it challenging to determine the precise function of any specific tegument protein. However, recent studies have made great headway in defining the interactions between tegument proteins, conserved across alphaherpesviruses, which facilitate tegument assembly and secondary envelopment. We summarize these recent advances and review what remains to be learned about the molecular interactions required to assemble mature alphaherpesvirus virions following the release of capsids from infected cell nuclei.

  11. HIV-1 envelope glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

    2017-08-22

    The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

  12. Jacketed lamp bulb envelope

    Science.gov (United States)

    MacLennan, Donald A.; Turner, Brian P.; Gitsevich, Aleksandr; Bass, Gary K.; Dolan, James T.; Kipling, Kent; Kirkpatrick, Douglas A.; Leng, Yongzhang; Levin, Izrail; Roy, Robert J.; Shanks, Bruce; Smith, Malcolm; Trimble, William C.; Tsai, Peter

    2001-01-01

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  13. Thermal Activated Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    search procedure, the combination of materials and their bonding temperature is found in relation to the envelope effect on a thermal environment inside a defined space. This allows the designer to articulate dynamic composites with time-based thermal functionality, related to the material dynamics...

  14. Vaccine Induction of Antibodies Against a Structurally Heterogeneous Site of Immune Pressure within HIV-1 Envelope Protein Variable Regions 1 and 2

    Science.gov (United States)

    Liao, Hua-Xin; Bonsignori, Mattia; Alam, S. Munir; McLellan, Jason S.; Tomaras, Georgia D.; Moody, M. Anthony; Kozink, Daniel M.; Hwang, Kwan-Ki; Chen, Xi; Tsao, Chun-Yen; Liu, Pinghuang; Lu, Xiaozhi; Parks, Robert J.; Montefiori, David C.; Ferrari, Guido; Pollara, Justin; Rao, Mangala; Peachman, Kristina K.; Santra, Sampa; Letvin, Norman L.; Karasavvas, Nicos; Yang, Zhi-Yong; Dai, Kaifan; Pancera, Marie; Gorman, Jason; Wiehe, Kevin; Nicely, Nathan I.; Rerks-Ngarm, Supachai; Nitayaphan, Sorachai; Kaewkungwal, Jaranit; Pitisuttithum, Punnee; Tartaglia, James; Sinangil, Faruk; Kim, Jerome H.; Michael, Nelson L.; Kepler, Thomas B.; Kwong, Peter D.; Mascola, John R.; Nabel, Gary J.; Pinter, Abraham; Zolla-Pazner, Susan; Haynes, Barton F.

    2013-01-01

    Summary The RV144 HIV-1 trial of the canary pox vector (ALVAC-HIV) plus the gp120 AIDSVAX B/E vaccine demonstrated an estimated efficacy of 31%, that correlated directly with antibodies to HIV-1 envelope variable regions 1 and 2 (V1–V2). Genetic analysis of trial viruses revealed increased vaccine efficacy against viruses matching the vaccine strain at V2 residue 169. Here, we isolated four V2 monoclonal antibodies from RV144 vaccinees that recognize residue 169, neutralize laboratory-adapted HIV-1, and mediate killing of field isolate HIV-1-infected CD4+ T cells. Crystal structures of two of the V2 antibodies demonstrated residue 169 can exist within divergent helical and loop conformations, which contrasted dramatically with the beta strand conformation previously observed with a broadly neutralizing antibody PG9. Thus, RV144 vaccine-induced immune pressure appears to target a region that may be both sequence variable and structurally polymorphic. Variation may signal sites of HIV-1 envelope vulnerability, providing vaccine designers with new options. PMID:23313589

  15. A consensus envelope protein domain III can induce neutralizing antibody responses against serotype 2 of dengue virus in non-human primates.

    Science.gov (United States)

    Chen, Hsin-Wei; Liu, Shih-Jen; Li, Yi-Shiuan; Liu, Hsueh-Hung; Tsai, Jy-Ping; Chiang, Chen-Yi; Chen, Mei-Yu; Hwang, Chyi-Sing; Huang, Chin-Cheng; Hu, Hui-Mei; Chung, Han-Hsuan; Wu, Sze-Hsien; Chong, Pele; Leng, Chih-Hsiang; Pan, Chien-Hsiung

    2013-07-01

    We have previously demonstrated that vaccination with a subunit dengue vaccine containing a consensus envelope domain III with aluminum phosphate elicits neutralizing antibodies against all four serotypes of dengue virus in mice. In this study, we evaluated the immunogenicity of the subunit dengue vaccine in non-human primates. After vaccination, monkeys that received the subunit vaccine with aluminum phosphate developed a significantly strong and long-lasting antibody response. A specific T cell response with cytokine production was also induced, and this correlated with the antibody response. Additionally, neutralizing antibodies against serotype 2 were detected in two of three monkeys. The increase in serotype-2-specific antibody titers and avidity observed in these two monkeys suggested that a serotype-2-biased antibody response occurs. These data provide evidence that a protective neutralizing antibody response was successfully elicited in non-human primates by the dengue subunit vaccine with aluminum phosphate adjuvant.

  16. Internal mail envelopes

    CERN Multimedia

    2003-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unusual stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  17. URGENT - Internal Mail Envelopes

    CERN Multimedia

    2007-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  18. URGENT - Internal Mail Envelopes

    CERN Multimedia

    Mail Office

    2004-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  19. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  20. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  1. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  2. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.   Mail Office

  3. INTERNAL CIRCULATION ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or a piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  4. Uncertain data envelopment analysis

    CERN Document Server

    Wen, Meilin

    2014-01-01

    This book is intended to present the milestones in the progression of uncertain Data envelopment analysis (DEA). Chapter 1 gives some basic introduction to uncertain theories, including probability theory, credibility theory, uncertainty theory and chance theory. Chapter 2 presents a comprehensive review and discussion of basic DEA models. The stochastic DEA is introduced in Chapter 3, in which the inputs and outputs are assumed to be random variables. To obtain the probability distribution of a random variable, a lot of samples are needed to apply the statistics inference approach. Chapter 4

  5. Nuclear envelope organization in papillary thyroid carcinoma

    OpenAIRE

    Fischer, A.H.; Taysavang, P.; Weber, C.J.; Wilson, K L

    2001-01-01

    Papillary thyroid carcinomas (PTCs) have characteristic nuclear shape changes compared to follicular-type thyroid epithelium. We tested the hypothesis that the altered nuclear shape results from altered distribution or expression of the major structural proteins of the nuclear envelope. Lamin A, lamin B1, lamin C, lamin B receptor (LBR), lamina-associated polypeptide 2 (LAP2), emerin, and nuclear pores were examined. PTC7s with typical nuclear features by H&E ...

  6. Elicitation of strong immune responses by a DNA vaccine expressing a secreted form of hepatitis C virus envelope protein E2 in murine and porcine animal models

    DEFF Research Database (Denmark)

    Li, Yiping; Kang, H.N.; Babiuk, L.A.

    2006-01-01

    AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without...... boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-gamma secreting cells, and cytotoxic T lymphocyte assays....... RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-like immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination, strategy induced significantly higher E2-specific antibody levels...

  7. Identification of two Isoforms of Vitelline Envelope Protein as Complementary Biomarkers to Vitellogenin in the Plasma of Rainbow Trout Exposed to 17beta-estradiol

    Science.gov (United States)

    In the present study, protein markers of estrogenic exposure in rainbow trout (Oncorhynchus mykiss) were isolated and identified using innovative sample preparation techniques followed by advanced MS and bioinformatics approaches. Juvenile trout were administered 17ß-estradiol t...

  8. Involvement of both the V2 and V3 Regions of the CCR5-Tropic Human Immunodeficiency Virus Type 1 Envelope in Reduced Sensitivity to Macrophage Inflammatory Protein

    Science.gov (United States)

    Maeda, Yosuke; Foda, Mohamed; Matsushita, Shuzo; Harada, Shinji

    2000-01-01

    To determine whether C-C chemokines play an important role in the phenotype switch of human immunodeficiency virus (HIV) from CCR5 to CXCR4 usage during the course of an infection in vivo, macrophage inflammatory protein (MIP)-1α-resistant variants were isolated from CCR5-tropic (R5) HIV-1 in vitro. The selected variants displayed reduced sensitivities to MIP-1α (fourfold) through CCR5-expressing CD4-HeLa/long terminal repeat–β-galactosidase (MAGI/CCR5) cells. The variants were also resistant to other natural ligands for CCR5, namely, MIP-1β (>4-fold) and RANTES (regulated upon activation, normal T-cell expressed and secreted) (6-fold). The env sequence analyses revealed that the variants had amino acid substitutions in V2 (valine 166 to methionine) and V3 (serine 303 to glycine), although the same V3 substitution appeared in virus passaged without MIP-1α. A single-round replication assay using a luciferase reporter HIV-1 strain pseudotyped with mutant envelopes confirmed that mutations in both V2 and V3 were necessary to confer the reduced sensitivity to MIP-1α, MIP-1β, and RANTES. However, the double mutant did not switch its chemokine receptor usage from CCR5 to CXCR4, indicating the altered recognition of CCR5 by this mutant. These results indicated that V2 combined with the V3 region of the CCR5-tropic HIV-1 envelope modulates the sensitivity of HIV-1 to C-C chemokines without altering the ability to use chemokine receptors. PMID:10644351

  9. Adaptive Architectural Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    . The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two......Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability...... different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up concept...

  10. Thermal Responsive Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    alterations, their respective durability and copper’s architectural (visual and transformative) aesthetic qualities. Through the use of an evolutionary solver, the composite structure of the elements are organised to find the bending behaviour specified by and for the thermal environments. The entire model......The paper presents an architectural computational method and model, which, through additive and subtractive processes, create composite elements with bending behaviour based on thermal variations in the surrounding climatic environment. The present effort is focused on the manipulation of assembly...... composite layers and their relative layer lengths thereby embedding the merged material effect to create a responsive behavioural architectural envelope. Copper and polypropylene are used as base materials for the composite structure due to their high differences in thermal expansion, surface emissivity...

  11. The HtrA-like serine protease PepD interacts with and modulates the Mycobacterium tuberculosis 35-kDa antigen outer envelope protein.

    Directory of Open Access Journals (Sweden)

    Mark J White

    2011-03-01

    Full Text Available Mycobacterium tuberculosis remains a significant global health concern largely due to its ability to persist for extended periods within the granuloma of the host. While residing within the granuloma, the tubercle bacilli are likely to be exposed to stress that can result in formation of aberrant proteins with altered structures. Bacteria encode stress responsive determinants such as proteases and chaperones to deal with misfolded or unfolded proteins. pepD encodes an HtrA-like serine protease and is thought to process proteins altered following exposure of M. tuberculosis to extra-cytoplasmic stress. PepD functions both as a protease and chaperone in vitro, and is required for aspects of M. tuberculosis virulence in vivo. pepD is directly regulated by the stress-responsive two-component signal transduction system MprAB and indirectly by extracytoplasmic function (ECF sigma factor SigE. Loss of PepD also impacts expression of other stress-responsive determinants in M. tuberculosis. To further understand the role of PepD in stress adaptation by M. tuberculosis, a proteomics approach was taken to identify binding proteins and possible substrates of this protein. Using subcellular fractionation, the cellular localization of wild-type and PepD variants was determined. Purified fractions as well as whole cell lysates from Mycobacterium smegmatis or M. tuberculosis strains expressing a catalytically compromised PepD variant were immunoprecipitated for PepD and subjected to LC-MS/MS analyses. Using this strategy, the 35-kDa antigen encoding a homolog of the PspA phage shock protein was identified as a predominant binding partner and substrate of PepD. We postulate that proteolytic cleavage of the 35-kDa antigen by PepD helps maintain cell wall homeostasis in Mycobacterium and regulates specific stress response pathways during periods of extracytoplasmic stress.

  12. Moisture Dynamics in Building Envelopes

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele

    2003-01-01

    The overall scope of this Thesis "Moisture dynamics in building envelopes" has been to characterise how the various porous insulation materials investigated performed hygrothermally under conditions similar to those in a typical building envelope. As a result of the changing temperature...

  13. Anisotropic charged core envelope star

    Science.gov (United States)

    Mafa Takisa, P.; Maharaj, S. D.

    2016-08-01

    We study a charged compact object with anisotropic pressures in a core envelope setting. The equation of state is quadratic in the core and linear in the envelope. There is smooth matching between the three regions: the core, envelope and the Reissner-Nordström exterior. We show that the presence of the electric field affects the masses, radii and compactification factors of stellar objects with values which are in agreement with previous studies. We investigate in particular the effect of electric field on the physical features of the pulsar PSR J1614-2230 in the core envelope model. The gravitational potentials and the matter variables are well behaved within the stellar object. We demonstrate that the radius of the core and the envelope can vary by changing the parameters in the speed of sound.

  14. The Lack of the Essential LptC Protein in the Trans-Envelope Lipopolysaccharide Transport Machine Is Circumvented by Suppressor Mutations in LptF, an Inner Membrane Component of the Escherichia coli Transporter

    KAUST Repository

    Benedet, Mattia

    2016-08-16

    The lipopolysaccharide (LPS) transport (Lpt) system is responsible for transferring LPS from the periplasmic surface of the inner membrane (IM) to the outer leaflet of the outer membrane (OM), where it plays a crucial role in OM selective permeability. In E. coli seven essential proteins are assembled in an Lpt trans-envelope complex, which is conserved in gamma-Proteobacteria. LptBFG constitute the IMABC transporter, LptDE form the OM translocon for final LPS delivery, whereas LptC, an IM-anchored protein with a periplasmic domain, interacts with the IM ABC transporter, the periplasmic protein LptA, and LPS. Although essential, LptC can tolerate several mutations and its role in LPS transport is unclear. To get insights into the functional role of LptC in the Lpt machine we searched for viable mutants lacking LptC by applying a strong double selection for lptC deletion mutants. Genome sequencing of viable Delta lptC mutants revealed single amino acid substitutions at a unique position in the predicted large periplasmic domain of the IM component LptF (LptF(SupC)). In complementation tests, lptF(SupC) mutants suppress lethality of both Delta lptC and lptC conditional expressionmutants. Our data show that mutations in a specific residue of the predicted LptF periplasmic domain can compensate the lack of the essential protein LptC, implicate such LptF domain in the formation of the periplasmic bridge between the IM and OM complexes, and suggest that LptC may have evolved to improve the performance of an ancestral six-component Lpt machine.

  15. The major envelope protein, GP(5), of a European porcine reproductive and respiratory syndrome virus contains a neutralization epitope in its N-terminal ectodomain

    NARCIS (Netherlands)

    Wissink, E.H.J.; Wijk, van H.A.R.; Kroese, M.V.; Weiland, E.; Meulenberg, J.J.M.; Rottier, P.J.M.; Rijn, van P.A.

    2003-01-01

    A set of neutralizing monoclonal antibodies (mAbs) directed against the GP5 protein of European type porcine reproductive and respiratory syndrome virus (PRRSV) has been produced previously (Weiland et al., 1999). This set reacted with a plaque-purified virus (PPV) subpopulation of Dutch isolate

  16. A comparative analysis on the physicochemical properties of tick-borne encephalitis virus envelope protein residues that affect its antigenic properties

    Czech Academy of Sciences Publication Activity Database

    Bukin, Y. S.; Dzhioev, Y.; Tkachev, S. E.; Kozlova, I.; Paramonov, A. I.; Růžek, Daniel; Qu, Z.; Zlobin, V. I.

    2017-01-01

    Roč. 238, JUN 15 (2017), s. 124-132 ISSN 0168-1702 Institutional support: RVO:60077344 Keywords : tick-borne encephalitis virus * E protein * physicochemical properties amino acid residue * antigen * antibody Subject RIV: EE - Microbiology, Virology Impact factor: 2.628, year: 2016

  17. Co-administration of recombinant major envelope proteins (rA27L and rH3L) of buffalopox virus provides enhanced immunogenicity and protective efficacy in animal models.

    Science.gov (United States)

    Kumar, Amit; Yogisharadhya, Revanaiah; Venkatesan, Gnanavel; Bhanuprakash, Veerakyathappa; Pandey, Awadh Bihari; Shivachandra, Sathish Bhadravati

    2017-05-01

    Buffalopox virus (BPXV) and other vaccinia-like viruses (VLVs) are causing an emerging/re-emerging zoonosis affecting buffaloes, cattle and humans in India and other countries. A27L and H3L are immuno-dominant major envelope proteins of intracellular mature virion (IMV) of orthopoxviruses (OPVs) and are highly conserved with an ability to elicit neutralizing antibodies. In the present study, two recombinant proteins namely; rA27L (21S to E110; ∼30 kDa) and rH3L(1M to I280; ∼50 kDa) of BPXV-Vij/96 produced from Escherichia coli were used in vaccine formulation. A combined recombinant subunit vaccine comprising rA27L and rH3L antigens (10 μg of each) was used for active immunization of adult mice (20μg/dose/mice) with or without adjuvant (FCA/FIA) by intramuscular route. Immune responses revealed a gradual increase in antigen specific serum IgG as well as neutralizing antibody titers measured by using indirect-ELISA and serum neutralization test (SNT) respectively, which were higher as compared to that elicited by individual antigens. Suckling mice passively administered with combined anti-A27L and anti-H3L sera showed a complete (100%) pre-exposure protection upon challenge with virulent BPXV. Conclusively, this study highlights the potential utility of rA27L and rH3L proteins as safer candidate prophylactic antigens in combined recombinant subunit vaccine for buffalopox as well as passive protective efficacy of combined sera in employing better pre-exposure protection against virulent BPXV. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. MEPPitope: spatial, electrostatic and secondary structure perturbations in the post-fusion Dengue virus envelope protein highlights known epitopes and conserved residues in the Zika virus [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    2016-06-01

    Full Text Available The dramatic transformation of the Zika virus (ZIKV from a relatively unknown virus to a pathogen generating global-wide panic has exposed the dearth of detailed knowledge about this virus. Decades of research in the related Dengue virus (DENV, finally culminating in a vaccine registered for use in endemic regions (CYD-TDV, provides key insights in developing strategies for tackling ZIKV. The previously established MEPP methodology compares two conformations of the same protein and identifies residues with significant spatial and electrostatic perturbations. In the current work, MEPP analyzed the pre-and post-fusion DENV type 2 envelope (E protein, and identified several known epitopes (His317, Tyr299, Glu26, Arg188, etc. (MEPPitope. These residues are overwhelmingly conserved in ZIKV and all DENV serotypes. Characterization of α-helices in E-proteins show that α1 is not conserved in the sequence space of ZIKV and DENV. Furthermore, perturbation of α1 in the post-fusion DENV structure includes a known epitope Asp215, a residue absent in the pre-fusion α1. A cationic β-sheet in the GAG-binding domain that is stereochemically equivalent in ZIKV and all DENV serotypes is also highlighted due to a residue pair (Arg286-Arg288 that has a significant electrostatic polarity reversal upon fusion. Finally, two highly conserved residues (Thr32 and Thr40, with little emphasis in existing literature, are found to have significant electrostatic perturbation. Thus, a combination of different computational methods enable the rapid and rational detection of critical residues that can be made the target of small drugs, or as epitopes in the search for an elusive therapy or vaccine that neutralizes multiple members of the Flaviviridae family.

  19. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  20. Distinct functional domains within the acidic cluster of tegument protein pp28 required for trafficking and cytoplasmic envelopment of human cytomegalovirus.

    Science.gov (United States)

    Seo, Jun-Young; Jeon, Hyejin; Hong, Sookyung; Britt, William J

    2016-10-01

    Human cytomegalovirus UL99-encoded tegument protein pp28 contains a 16 aa acidic cluster that is required for pp28 trafficking to the assembly compartment (AC) and the virus assembly. However, functional signals within the acidic cluster of pp28 remain undefined. Here, we demonstrated that an acidic cluster rather than specific sorting signals was required for trafficking to the AC. Recombinant viruses with chimeric pp28 proteins expressing non-native acidic clusters exhibited delayed viral growth kinetics and decreased production of infectious virus, indicating that the native acidic cluster of pp28 was essential for wild-type virus assembly. These results suggested that the acidic cluster of pp28 has distinct functional domains required for trafficking and for efficient virus assembly. The first half (aa 44-50) of the acidic cluster was sufficient for pp28 trafficking, whereas the native acidic cluster consisting of aa 51-59 was required for the assembly of wild-type levels of infectious virus.

  1. Characterization of hepatitis C virus recombinants with chimeric E1/E2 envelope proteins and identification of single amino acids in the E2 stem region important for entry

    DEFF Research Database (Denmark)

    Carlsen, Thomas H R; Scheel, Troels K H; Ramirez, Santseharay

    2013-01-01

    The hepatitis C virus (HCV) envelope proteins E1 and E2 play a key role in host cell entry and represent important targets for vaccine and drug development. Here, we characterized HCV recombinants with chimeric E1/E2 complexes in vitro. Using genotype 1a/2a JFH1-based recombinants expressing 1a...... core-NS2, we exchanged E2 with functional isolate sequences of genotypes 1a (alternative isolate), 1b, and 2a. While the 1a-E2 exchange did not impact virus viability, the 2a-E2 recombinant was nonviable. After E2 exchange from three 1b isolates, long delays were observed before spread of infection....... For recovered 1b-E2 recombinants, single E2 stem region amino acid changes were identified at residues 706, 707, and 710. In reverse genetic studies, these mutations increased infectivity titers by ~100-fold, apparently without influencing particle stability or cell binding although introducing slight decrease...

  2. Integrated process for the purification and immobilization of the envelope protein domain III of dengue virus type 2 expressed in Rachiplusia nu larvae and its potential application in a diagnostic assay.

    Science.gov (United States)

    Smith, María Emilia; Targovnik, Alexandra Marisa; Cerezo, Julieta; Morales, María Alejandra; Miranda, María Victoria; Talou, Julián Rodríguez

    2017-03-01

    Dengue incidence has grown dramatically in the last years, with about 40% of the world population at risk of infection. Recently, a vaccine developed by Sanofi Pasteur has been registered, but only in a few countries. Moreover, specific antiviral drugs are not available. Thus, an efficient and accurate diagnosis is important for disease management. To develop a low-cost immunoassay for dengue diagnosis, in the present study we expressed the envelope protein domain III of dengue virus type 2 in Rachiplusia nu larvae by infection with a recombinant baculovirus. The antigen was expressed as a fusion to hydrophobin I (DomIIIHFBI) to easily purify it by an aqueous two-phase system (ATPS) and to efficiently immobilize it in immunoassay plates. A high level of recombinant DomIIIHFBI was obtained in R. nu, where yields reached 4.5 mg per g of larva. Also, we were able to purify DomIIIHFBI by an ATPS with 2% of Triton X-114, reaching a yield of 73% and purity higher than 80% in a single purification step. The recombinant DomIIIHFBI was efficiently immobilized in hydrophobic surface plates. The immunoassay we developed with the immobilized antigen was able to detect IgG specific for dengue virus type 2 in serum samples and not for other serotypes. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Genomic Methylation Inhibits Expression of Hepatitis B Virus Envelope Protein in Transgenic Mice: A Non-Infectious Mouse Model to Study Silencing of HBV Surface Antigen Genes.

    Science.gov (United States)

    Graumann, Franziska; Churin, Yuri; Tschuschner, Annette; Reifenberg, Kurt; Glebe, Dieter; Roderfeld, Martin; Roeb, Elke

    2015-01-01

    The Hepatitis B virus genome persists in the nucleus of virus infected hepatocytes where it serves as template for viral mRNA synthesis. Epigenetic modifications, including methylation of the CpG islands contribute to the regulation of viral gene expression. The present study investigates the effects of spontaneous age dependent loss of hepatitis B surface protein- (HBs) expression due to HBV-genome specific methylation as well as its proximate positive effects in HBs transgenic mice. Liver and serum of HBs transgenic mice aged 5-33 weeks were analyzed by Western blot, immunohistochemistry, serum analysis, PCR, and qRT-PCR. From the third month of age hepatic loss of HBs was observed in 20% of transgenic mice. The size of HBs-free area and the relative number of animals with these effects increased with age and struck about 55% of animals aged 33 weeks. Loss of HBs-expression was strongly correlated with amelioration of serum parameters ALT and AST. In addition lower HBs-expression went on with decreased ER-stress. The loss of surface protein expression started on transcriptional level and appeared to be regulated epigenetically by DNA methylation. The amount of the HBs-expression correlated negatively with methylation of HBV DNA in the mouse genome. Our data suggest that methylation of specific CpG sites controls gene expression even in HBs-transgenic mice with truncated HBV genome. More important, the loss of HBs expression and intracellular aggregation ameliorated cell stress and liver integrity. Thus, targeted modulation of HBs expression may offer new therapeutic approaches. Furthermore, HBs-transgenic mice depict a non-infectious mouse model to study one possible mechanism of HBs gene silencing by hypermethylation.

  4. Host cell selection of Murray Valley encephalitis virus variants altered at an RGD sequence in the envelope protein and in mouse virulence.

    Science.gov (United States)

    Lobigs, M; Usha, R; Nestorowicz, A; Marshall, I D; Weir, R C; Dalgarno, L

    1990-06-01

    We have passaged the prototype strain of Murray Valley encephalitis virus in SW13 (human) cells, sequenced the E and M genes, and examined the virulence of the passaged virus for 21-day-old mice following intracranial and intraperitoneal inoculation. Six independent passage series were carried out: four in the presence of mouse hyperimmune ascitic fluid and two without antibody. Changes were observed in the E protein deduced amino acid sequence for each of the six 10th passage stocks sequenced. Eleven changes were observed in total for the six stocks sequenced; these were at residues 117, 118, 390, 423, and 460. Nine of the changes were nonconservative. Five of the six passaged variants were altered at Asp 390 which is part of an Arg-Gly-Asp (RGD) sequence. This change resulted from adaptation to SW13 cells rather than from antibody selection. The RGD sequence (and residue 423) falls within a region which is highly conserved between flaviviruses and is strongly hydrophilic. All five variants which were altered at Asp 390 were attenuated in 21-day-old mice following i.p. inoculation. We propose that the domain of E encompassing the RGD sequence is an important determinant of flavivirus pathogenicity.

  5. The Nrf1 CNC/bZIP protein is a nuclear envelope-bound transcription factor that is activated by t-butyl hydroquinone but not by endoplasmic reticulum stressors.

    Science.gov (United States)

    Zhang, Yiguo; Lucocq, John M; Hayes, John D

    2009-03-01

    In rat liver RL-34 cells, endogenous Nrf1 (nuclear factor-erythroid 2 p45 subunit-related factor 1) is localized in the ER (endoplasmic reticulum) where it exists as a glycosylated protein. Electron microscopy has demonstrated that ectopic Nrf1 in COS-1 cells is located in the ER and the NE (nuclear envelope). Subcellular fractionation, together with a membrane proteinase protection assay, revealed that Nrf1 is an integral membrane protein with both luminal and cytoplasmic domains. The N-terminal 65 residues of Nrf1 direct its integration into the ER and NE membranes and tether it to a Triton X-100-resistant membrane microdomain that is associated with lipid rafts. The activity of Nrf1 was increased by the electrophile tBHQ (t-butyl hydroquinone) probably through an N-terminal domain-dependent process. We found that the NST (Asn/Ser/Thr-rich) domain, along with AD1 (acidic domain 1), contributes positively to the transactivation activity of full-length Nrf1. Furthermore, the NST domain contains seven putative -Asn-Xaa-Ser/Thr- glycosylation sites and, when glycosylation was prevented by replacing all of the seven asparagine residues with either glutamine (Nrf1(1-7xN/Q)) or aspartic acid (Nrf1(1-7xN/D)), the former multiple point mutant possessed less activity than the wild-type factor, whereas the latter mutant exhibited substantially greater activity. Lastly, the ER stressors tunicamycin, thapsigargin and Brefeldin A were found to inhibit basal Nrf1 activity by approximately 25%, and almost completely prevented induction of Nrf1-mediated transactivation by tBHQ. Collectively, these results suggest that the activity of Nrf1 critically depends on its topology within the ER, and that this is modulated by redox stressors, as well as by its glycosylation status.

  6. The LHC on an envelope

    CERN Multimedia

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays ...

  7. The LHC in an envelope

    CERN Multimedia

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays de Gex (Ferney-Voltaire, Prévessin...

  8. Parasitic Events in Envelope Analysis

    Directory of Open Access Journals (Sweden)

    J. Doubek

    2001-01-01

    Full Text Available Envelope analysis allows fast fault location of individual gearboxes and parts of bearings by repetition frequency determination of the mechanical catch of an amplitude-modulated signal. Systematic faults arise when using envelope analysis on a signal with strong changes. The source of these events is the range of function definition of used in convolution integral definition. This integral is used for Hilbert image calculation of analyzed signal. Overshoots (almost similar to Gibbs events on a synthetic signal using the Fourier series are result from these faults. Overshoots are caused by parasitic spectral lines in the frequency domain, which can produce faulty diagnostic analysis.This paper describes systematic arising during faults rising by signal numerical calculation using envelope analysis with Hilbert transform. It goes on to offer a mathematical analysis of these systematic faults.

  9. Enhancement of feline immunodeficiency virus infection after immunization with envelope glycoprotein subunit vaccines.

    NARCIS (Netherlands)

    C.H.J. Siebelink (Kees); E.J. Tijhaar (Edwin); R.C. Huisman (Robin); W. Huisman (Willem); A. de Ronde; I.H. Darby; M.J. Francis; G.F. Rimmelzwaan (Guus); A.D.M.E. Osterhaus (Albert)

    1995-01-01

    textabstractCats were immunized three times with different recombinant feline immunodeficiency virus (FIV) candidate vaccines. Recombinant vaccinia virus (rVV)-expressed envelope glycoprotein with (vGR657) or without (vGR657 x 15) the cleavage site and an FIV envelope bacterial fusion protein

  10. Traffic to the inner membrane of the nuclear envelope

    NARCIS (Netherlands)

    Laba, Justyna K.; Steen, Anton; Veenhoff, Liesbeth M.

    Past research has yielded valuable insight into the mechanisms that regulate the nuclear transport of soluble molecules like transcription factors and mRNA. Much less is known about the mechanisms responsible for the transportation of membrane proteins to the inner membrane of the nuclear envelope.

  11. Optimum Insulation of Building Envelopes

    DEFF Research Database (Denmark)

    Svendsen, Sv Aa Højgaard

    1997-01-01

    The problem of optimising building envelopes with respect to the overall aim of stimulating a sustainable development is described.A proposal is given for performing an optmization based on the priciple of making the same effort of saving energy in the building as supplying the building with ener...

  12. Handbook on data envelopment analysis

    CERN Document Server

    Cooper, William W; Zhu, Joe

    2011-01-01

    Focusing on extensively used Data Envelopment Analysis topics, this volume aims to both describe the state of the field and extend the frontier of DEA research. New chapters include DEA models for DMUs, network DEA, models for supply chain operations and applications, and new developments.

  13. Herpes Simplex Virus 1 Envelope Cholesterol Facilitates Membrane Fusion

    Directory of Open Access Journals (Sweden)

    George A. Wudiri

    2017-12-01

    Full Text Available Methyl beta-cyclodextrin (MβCD treatment of herpes simplex virus 1 (HSV-1 reduced envelope cholesterol levels and inhibited viral entry and infectivity in several cell types, regardless of the dependence of entry on endocytosis or low pH. Viral protein composition was similar in MβCD-treated and untreated virions, and ultrastructural analysis by electron microscopy revealed that cholesterol removal did not grossly affect virion structure or integrity. Removal of envelope cholesterol greatly reduced virion fusion activity as measured by fusion-from-without, suggesting that virion cholesterol is critical for the step of membrane fusion. MβCD-treatment of HSV-1 did not reduce viral attachment to the cells nor endocytic uptake of HSV-1 from the cell surface. The pre-fusion form of gB present in the HSV-1 envelope undergoes conformational changes in response to mildly acidic pH. These gB changes occurred independently of envelope cholesterol. Removal of cholesterol compromised virion stability as measured by recovery of infectivity following cycles of freeze-thaw. Taken together, the data suggest that HSV-1 envelope cholesterol is important for viral entry and infectivity due to a critical role in membrane fusion.

  14. A tetravalent virus-like particle vaccine designed to display domain III of dengue envelope proteins induces multi-serotype neutralizing antibodies in mice and macaques which confer protection against antibody dependent enhancement in AG129 mice.

    Directory of Open Access Journals (Sweden)

    Viswanathan Ramasamy

    2018-01-01

    Full Text Available Dengue is one of the fastest spreading vector-borne diseases, caused by four antigenically distinct dengue viruses (DENVs. Antibodies against DENVs are responsible for both protection as well as pathogenesis. A vaccine that is safe for and efficacious in all people irrespective of their age and domicile is still an unmet need. It is becoming increasingly apparent that vaccine design must eliminate epitopes implicated in the induction of infection-enhancing antibodies.We report a Pichia pastoris-expressed dengue immunogen, DSV4, based on DENV envelope protein domain III (EDIII, which contains well-characterized serotype-specific and cross-reactive epitopes. In natural infection, <10% of the total neutralizing antibody response is EDIII-directed. Yet, this is a functionally relevant domain which interacts with the host cell surface receptor. DSV4 was designed by in-frame fusion of EDIII of all four DENV serotypes and hepatitis B surface (S antigen and co-expressed with unfused S antigen to form mosaic virus-like particles (VLPs. These VLPs displayed EDIIIs of all four DENV serotypes based on probing with a battery of serotype-specific anti-EDIII monoclonal antibodies. The DSV4 VLPs were highly immunogenic, inducing potent and durable neutralizing antibodies against all four DENV serotypes encompassing multiple genotypes, in mice and macaques. DSV4-induced murine antibodies suppressed viremia in AG129 mice and conferred protection against lethal DENV-4 virus challenge. Further, neither murine nor macaque anti-DSV4 antibodies promoted mortality or inflammatory cytokine production when passively transferred and tested in an in vivo dengue disease enhancement model of AG129 mice.Directing the immune response to a non-immunodominant but functionally relevant serotype-specific dengue epitope of the four DENV serotypes, displayed on a VLP platform, can help minimize the risk of inducing disease-enhancing antibodies while eliciting effective tetravalent

  15. The herpes simplex virus UL20 protein functions in glycoprotein K (gK intracellular transport and virus-induced cell fusion are independent of UL20 functions in cytoplasmic virion envelopment

    Directory of Open Access Journals (Sweden)

    Kousoulas Konstantin G

    2007-11-01

    Full Text Available Abstract The HSV-1 UL20 protein (UL20p and glycoprotein K (gK are both important determinants of cytoplasmic virion morphogenesis and virus-induced cell fusion. In this manuscript, we examined the effect of UL20 mutations on the coordinate transport and Trans Golgi Network (TGN localization of UL20p and gK, virus-induced cell fusion and infectious virus production. Deletion of 18 amino acids from the UL20p carboxyl terminus (UL20 mutant 204t inhibited intracellular transport and cell-surface expression of both gK and UL20, resulting in accumulation of UL20p and gK in the endoplasmic reticulum (ER in agreement with the inability of 204t to complement UL20-null virus replication and virus-induced cell fusion. In contrast, less severe carboxyl terminal deletions of either 11 or six amino acids (UL20 mutants 211t and 216t, respectively allowed efficient UL20p and gK intracellular transport, cell-surface expression and TGN colocalization. However, while both 211t and 216t failed to complement for infectious virus production, 216t complemented for virus-induced cell fusion, but 211t did not. These results indicated that the carboxyl terminal six amino acids of UL20p were crucial for infectious virus production, but not involved in intracellular localization of UL20p/gK and concomitant virus-induced cell fusion. In the amino terminus of UL20, UL20p mutants were produced changing one or both of the Y38 and Y49 residues found within putative phosphorylation sites. UL20p tyrosine-modified mutants with both tyrosine residues changed enabled efficient intracellular transport and TGN localization of UL20p and gK, but failed to complement for either infectious virus production, or virus-induced cell fusion. These results show that UL20p functions in cytoplasmic envelopment are separable from UL20 functions in UL20p intracellular transport, cell surface expression and virus-induced cell fusion.

  16. HVJ liposomes and HVJ envelope vectors.

    Science.gov (United States)

    Kaneda, Yasufumi

    2011-10-01

    This protocol describes techniques for construction of fusion-mediated vectors based on inactivated HVJ (hemagglutinating virus of Japan; Sendai virus). HVJ liposomes are constructed by fusing liposomes containing DNA with inactivated HVJ. The HVJ envelope vector, a more simplified vector, incorporates DNA into inactivated HVJ particles without liposomes. Both vectors have many advantages. They can be used to introduce proteins, peptides, oligonucleotides (including antisense oligonucleotides, decoy oligonucleotides, and ribozymes), and short interfering RNA (siRNA), as well as plasmid DNA, into cultured cells in vitro and into organs in vivo. Fusion-mediated delivery avoids the degradation of therapeutic molecules before reaching the cytoplasm. Finally, repeated injection of the vector in vivo is not inhibited and even enhances the effects of the delivered molecules. These vectors have been used in many gene therapy experiments in animal models to address problems such as liver cirrhosis, hearing impairment, ischemic brain damage, peripheral arterial diseases, and cancers. This protocol describes methods for the preparation of HVJ liposomes and of HVJ envelope vectors and their use in delivery of plasmid DNA into various cells and tissues.

  17. The envelopes of amphibian oocytes: physiological modifications in Bufo arenarum

    Directory of Open Access Journals (Sweden)

    Sánchez Mercedes

    2003-02-01

    Full Text Available Abstract A characterization of the Amphibian Bufo arenarum oocyte envelope is presented. It was made in different functional conditions of the oocyte: 1 when it has been released into the coelomic cavity during ovulation (surrounded by the coelomic envelope, (CE, 2 after it has passed through the oviduct and is deposed (surrounded by the viteline envelope, (VE, and 3 after oocyte activation (surrounded by the fertilization envelope, (FE. The characterization was made by SDS-PAGE followed by staining for protein and glycoproteins. Labeled lectins were used to identify glycosidic residues both in separated components on nitrocellulose membranes or in intact oocytes and embryos. Proteolytic properties of the content of the cortical granules were also analyzed. After SDS-PAGE of CE and VE, a different protein pattern was observed. This is probably due to the activity of a protease present in the pars recta of the oviduct. Comparison of the SDS-PAGE pattern of VE and FE showed a different mobility for one of the glycoproteins, gp75. VE and FE proved to have different sugar residues in their oligosaccharide chains. Mannose residues are only present in gp120 of the three envelopes. N-acetyl-galactosamine residues are present in all of the components, except for gp69 in the FE. Galactose residues are present mainly in gp120 of FE. Lectin-binding assays indicate the presence of glucosamine, galactose and N-acetyl galactosamine residues and the absence (or non-availability of N-acetyl-glucosamine or fucose residues on the envelopes surface. The cortical granule product (CGP shows proteolytic activity on gp75 of the VE.

  18. A Strategy for O-Glycoproteomics of Enveloped Viruses-the O-Glycoproteome of Herpes Simplex Virus Type 1

    DEFF Research Database (Denmark)

    Bagdonaite, Ieva; Nordén, Rickard; Joshi, Hiren J

    2015-01-01

    present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1) as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B...

  19. Diversity in the fertilization envelopes of echinoderms.

    Science.gov (United States)

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L; Ramos, Isabela; Wessel, Gary M

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium-induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here, we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all, of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, and rendezvin. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs decreased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, but different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation for cell surface changes in sea urchins has been shifted to later in oogenesis, and perhaps reflects the meiotic differences among the species-sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxons in which eggs have completed meiosis prior to fertilization. © 2013 Wiley Periodicals, Inc.

  20. Diversity in the fertilization envelopes of echinoderms

    Science.gov (United States)

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L.; Wessel, Gary M.

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, rendezvin, and ovoperoxidase. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs deceased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, and different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation of the cell surface changes in sea urchins has been shifted to later in oogenesis and perhaps reflects the meiotic differences among the species–sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxa in which eggs have completed meiosis prior to fertilization. PMID:23331915

  1. Cell Cycle Dynamics of the Nuclear Envelope

    Directory of Open Access Journals (Sweden)

    Roland Foisner

    2003-01-01

    Full Text Available The nuclear envelope (NE consists of an inner and an outer membrane, nuclear pore complexes, and the underlying nuclear lamina, a filamentous scaffold structure formed by lamins. The inner membrane is linked to the lamina and chromatin by its integral membrane proteins, such as lamin B receptor (LBR, emerin, and various isoforms of lamina-associated polypeptides (LAP 1 and 2, which bind lamins and/or chromatin. During mitosis, the NE is disassembled upon phosphorylation of its core components, and the NE is torn apart by a dynein-driven microtubule-dependent mechanism. Nuclear reassembly after sister chromatid separation requires a timely coordinated and dephosphorylation-dependent association of lamin-binding proteins and lamins with chromosomal proteins and targeting of membranes to specific sites on chromosomes. Various chromatin-binding domains in lamina proteins, such as the LEM domain, present in all LAP2 isoforms and in emerin, as well as unique regions in lamina proteins and in specific LAP2 isoforms have been implicated in defined steps of NE reformation. Furthermore, novel mechanisms of membrane fusion involving Ran GTPase are just beginning to emerge.

  2. A survey of CN in circumstellar envelopes

    NARCIS (Netherlands)

    Bachiller, R; Fuente, A; Bujarrabal, [No Value; Colomer, F; Loup, C; Omont, A; deJong, T

    We have conducted a survey of CN N=2-1 and N=1-0 line emission in the envelopes of evolved stars. The sample consists of 42 objects, including C-rich and O-rich envelopes, S-stars, detached envelopes, and proto-planetary nebulae. Confident detections have been achieved in 30 objects. Both CN lines

  3. The plant LINC complex at the nuclear envelope.

    Science.gov (United States)

    Tatout, Christophe; Evans, David E; Vanrobays, Emmanuel; Probst, Aline V; Graumann, Katja

    2014-06-01

    Significant advances in understanding the plant nuclear envelope have been made over the past few years; indeed, knowledge of the protein network at the nuclear envelope is rapidly growing. One such network, the linker of nucleoskeleton and cytoskeleton (LINC) complex, is known in animals to connect chromatin to the cytoskeleton through the nuclear envelope. The LINC complex is made of Sad1/Unc84 (SUN) and Klarsicht/Anc1/Syne1 homology (KASH) proteins which have been recently characterized in plants. SUN proteins are located within the inner nuclear membrane, while the KASH proteins are included into the outer nuclear membrane. SUN and KASH domains interact and bridge the two nuclear membranes. In Arabidopsis, KASH proteins also interact with the tryptophan-proline-proline (WPP) domain-interacting tail-anchored protein 1 (WIT1), associated with the nuclear pore complex and with myosin XI-i which directly interacts with the actin cytoskeleton. Although evidence for a plant LINC complex connecting the nucleus to the cytoskeleton is growing, its interaction with chromatin is still unknown, but knowledge gained from animal models strongly suggests its existence in plants. Possible functions of the plant LINC complex in cell division, nuclear shape, and chromatin organization are discussed.

  4. Targeted chemotherapy against intraperitoneally disseminated colon carcinoma using a cationized gelatin–conjugated HVJ envelope vector

    National Research Council Canada - National Science Library

    Hidetoshi Mima; Seiji Yamamoto; Makoto Ito; Ryuji Tomoshige; Yasuhiko Tabata; Katsuto Tamai; Yasufumi Kaneda

    2006-01-01

    The hemagglutinating virus of Japan envelope (HVJ-E; Sendai virus) vector derived from inactivated HVJ particles can be used to deliver DNA, proteins, and drugs into cells both in vitro and in vivo...

  5. Fusion of reconstituted influenza virus envelopes with liposomes mediated by streptavidin/biotin interactions

    NARCIS (Netherlands)

    Schoen, P; Leserman, L; Wilschut, J

    1996-01-01

    Reconstituted influenza virus envelopes (virosomes) containing the viral hemagglutinin (HA) represent an efficient fusogenic cellular delivery system, By interaction of HA with its natural receptors, sialylated lipids (gangliosides) or proteins, virosomes bind to cells and, following endocytic

  6. Maturation of HIV envelope glycoprotein precursors by cellular endoproteases.

    Science.gov (United States)

    Moulard, M; Decroly, E

    2000-11-10

    The entry of enveloped viruses into its host cells is a crucial step for the propagation of viral infection. The envelope glycoprotein complex controls viral tropism and promotes the membrane fusion process. The surface glycoproteins of enveloped viruses are synthesized as inactive precursors and sorted through the constitutive secretory pathway of the infected cells. To be infectious, most of the viruses require viral envelope glycoprotein maturation by host cell endoproteases. In spite of the strong variability of primary sequences observed within different viral envelope glycoproteins, the endoproteolytical cleavage occurs mainly in a highly conserved domain at the carboxy terminus of the basic consensus sequence (Arg-X-Lys/Arg-Arg downward arrow). The same consensus sequence is recognized by the kexin/subtilisin-like serine proteinases (so called convertases) in many cellular substrates such as prohormones, proprotein of receptors, plasma proteins, growth factors and bacterial toxins. Therefore, several groups of investigators have evaluated the implication of convertases in viral envelope glycoprotein cleavage. Using the vaccinia virus overexpression system, furin was first shown to mediate the proteolytic maturation of both human immunodeficiency virus (HIV-1) and influenza virus envelope glycoproteins. In vitro studies demonstrated that purified convertases directly and specifically cleave viral envelope glycoproteins. Although these studies suggested the participation of several enzymes belonging to the convertases family, recent data suggest that other protease families may also participate in the HIV envelope glycoprotein processing. Their role in the physiological maturation process is still hypothetical and the molecular mechanism of the cleavage is not well documented. Crystallization of the hemagglutinin precursor (HA0) of influenza virus allowed further understanding of the molecular interaction between viral precursors and the cellular endoproteases

  7. Safeguards Envelope Progress FY08

    Energy Technology Data Exchange (ETDEWEB)

    Robert Bean; Richard Metcalf; Aaron Bevill

    2008-09-01

    The Safeguards Envelope Project met its milestones by creating a rudimentary safeguards envelope, proving the value of the approach on a small scale, and determining the most appropriate path forward. The Idaho Chemical Processing Plant’s large cache of reprocessing process monitoring data, dubbed UBER Data, was recovered and used in the analysis. A probabilistic Z test was used on a Markov Monte Carlo simulation of expected diversion data when compared with normal operating data. The data regarding a fully transient event in a tank was used to create a simple requirement, representative of a safeguards envelope, whose impact was a decrease in operating efficiency by 1.3% but an increase in material balance period of 26%. This approach is operator, state, and international safeguards friendly and should be applied to future reprocessing plants. Future requirements include tank-to-tank correlations in reprocessing facilities, detailed operations impact studies, simulation inclusion, automated optimization, advanced statistics analysis, and multi-attribute utility analysis.

  8. Determinants of the Bovine Leukemia Virus Envelope Glycoproteins Involved in Infectivity, Replication and Pathogenesis

    Directory of Open Access Journals (Sweden)

    Alix de Brogniez

    2016-03-01

    Full Text Available Interaction of viral envelope proteins with host cell membranes has been extensively investigated in a number of systems. However, the biological relevance of these interactions in vivo has been hampered by the absence of adequate animal models. Reverse genetics using the bovine leukemia virus (BLV genome highlighted important functional domains of the envelope protein involved in the viral life cycle. For example, immunoreceptor tyrosine-based activation motifs (ITAM of the envelope transmembrane protein (TM are essential determinants of infection. Although cell fusion directed by the aminoterminal end of TM is postulated to be essential, some proviruses expressing fusion-deficient envelope proteins unexpectedly replicate at wild-type levels. Surprisingly also, a conserved N-linked glycosylation site of the extracellular envelope protein (SU inhibits cell-to-cell transmission suggesting that infectious potential has been limited during evolution. In this review, we summarize the knowledge pertaining to the BLV envelope protein in the context of viral infection, replication and pathogenesis.

  9. Determinants of the Bovine Leukemia Virus Envelope Glycoproteins Involved in Infectivity, Replication and Pathogenesis

    Science.gov (United States)

    de Brogniez, Alix; Mast, Jan; Willems, Luc

    2016-01-01

    Interaction of viral envelope proteins with host cell membranes has been extensively investigated in a number of systems. However, the biological relevance of these interactions in vivo has been hampered by the absence of adequate animal models. Reverse genetics using the bovine leukemia virus (BLV) genome highlighted important functional domains of the envelope protein involved in the viral life cycle. For example, immunoreceptor tyrosine-based activation motifs (ITAM) of the envelope transmembrane protein (TM) are essential determinants of infection. Although cell fusion directed by the aminoterminal end of TM is postulated to be essential, some proviruses expressing fusion-deficient envelope proteins unexpectedly replicate at wild-type levels. Surprisingly also, a conserved N-linked glycosylation site of the extracellular envelope protein (SU) inhibits cell-to-cell transmission suggesting that infectious potential has been limited during evolution. In this review, we summarize the knowledge pertaining to the BLV envelope protein in the context of viral infection, replication and pathogenesis. PMID:27023592

  10. Nuclear envelopathies: a complex LINC between nuclear envelope and pathology.

    Science.gov (United States)

    Janin, Alexandre; Bauer, Delphine; Ratti, Francesca; Millat, Gilles; Méjat, Alexandre

    2017-08-30

    Since the identification of the first disease causing mutation in the gene coding for emerin, a transmembrane protein of the inner nuclear membrane, hundreds of mutations and variants have been found in genes encoding for nuclear envelope components. These proteins can be part of the inner nuclear membrane (INM), such as emerin or SUN proteins, outer nuclear membrane (ONM), such as Nesprins, or the nuclear lamina, such as lamins A and C. However, they physically interact with each other to insure the nuclear envelope integrity and mediate the interactions of the nuclear envelope with both the genome, on the inner side, and the cytoskeleton, on the outer side. The core of this complex, called LINC (LInker of Nucleoskeleton to Cytoskeleton) is composed of KASH and SUN homology domain proteins. SUN proteins are INM proteins which interact with lamins by their N-terminal domain and with the KASH domain of nesprins located in the ONM by their C-terminal domain.Although most of these proteins are ubiquitously expressed, their mutations have been associated with a large number of clinically unrelated pathologies affecting specific tissues. Moreover, variants in SUN proteins have been found to modulate the severity of diseases induced by mutations in other LINC components or interactors. For these reasons, the diagnosis and the identification of the molecular explanation of "nuclear envelopathies" is currently challenging.The aim of this review is to summarize the human diseases caused by mutations in genes coding for INM proteins, nuclear lamina, and ONM proteins, and to discuss their potential physiopathological mechanisms that could explain the large spectrum of observed symptoms.

  11. Serial femtosecond X-ray diffraction of enveloped virus microcrystals

    Directory of Open Access Journals (Sweden)

    Robert M. Lawrence

    2015-07-01

    Full Text Available Serial femtosecond crystallography (SFX using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ∼700 Å diameter. Microcrystals delivered in viscous agarose medium diffracted to ∼40 Å resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is an important step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  12. Enveloped virus flocculation and removal in osmolyte solutions.

    Science.gov (United States)

    Gencoglu, Maria F; Heldt, Caryn L

    2015-07-20

    Our ability to reduce infectious disease burden throughout the world has been greatly improved by the creation of vaccines. However, worldwide immunization rates are low. The two most likely reasons are the lack of sufficient distribution in underdeveloped countries and the high cost of vaccine products. The high costs are due to the difficulties of manufacturing individual vaccine products with specialized purification trains. In this study, we propose to use virus flocculation in osmolytes, followed by microfiltration, as an alternative vaccine purification operation. In our previous work, we demonstrated that osmolytes preferentially flocculate a non-enveloped virus, porcine parvovirus (PPV). In this work we show that osmolytes flocculate the enveloped virus, Sindbis virus heat resistant strain (SVHR), and demonstrate a >80% removal with a 0.2 μm microfilter membrane while leaving proteins in solution. The best osmolytes were tested for their ability to flocculate SVHR at different concentrations, pH and ionic strengths. Our best removal was 98% of SVHR in 0.3M mannitol at a pH of 5. We propose that osmolytes are able to flocculate hydrophobic non-enveloped and enveloped virus particles by the reduction of the hydration layer around the particles, which stimulates virus aggregation. Now that we have demonstrated that protecting osmolytes flocculate viruses, this method has the potential to be a future platform purification process for vaccines. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. The human granulocyte nucleus: Unusual nuclear envelope and heterochromatin composition.

    Science.gov (United States)

    Olins, Ada L; Zwerger, Monika; Herrmann, Harald; Zentgraf, Hanswalter; Simon, Amos J; Monestier, Marc; Olins, Donald E

    2008-05-01

    The human blood granulocyte (neutrophil) is adapted to find and destroy infectious agents. The nucleus of the human neutrophil has a segmented appearance, consisting of a linear or branched array of three or four lobes. Adequate levels of lamin B receptor (LBR) are necessary for differentiation of the lobulated nucleus. The levels of other components of the nuclear envelope may also be important for nuclear shape determination. In the present study, immunostaining and immunoblotting procedures explored the levels of various components of the nuclear envelope and heterochromatin, comparing freshly isolated human neutrophils with granulocytic forms of HL-60 cells, a tissue culture model system. In comparison to granulocytic HL-60 cells, blood neutrophil nuclear envelopes contain low-to-negligible amounts of LBR, lamins A/C, B1 and B2, LAP2beta and emerin. Surprisingly, a "mitotic" chromosome marker, H3(S10)phos, is elevated in neutrophil nuclei, compared to granulocytic HL-60 cells. Furthermore, neutrophil nuclei appear to be more fragile to methanol fixation, than observed with granulocytic HL-60 cells. Thus, the human neutrophil nucleus appears to be highly specialized, possessing a paucity of nuclear envelope-stabilizing proteins. In consequence, the neutrophil nucleus appears to be very malleable, supporting rapid migration through tight tissue spaces.

  14. Safeguards Envelope Progress FY10

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf

    2010-10-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details the additions to the advanced operating techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). Research this year focused on combining disparate pieces of data together to maximize operating time with minimal downtime due to safeguards. A Chi-Square and Croiser's cumulative sum were both included as part of the new analysis. Because of a major issue with the original data, the implementation of the two new tests did not add to the existing set of tests, though limited one-variable optimization made a small increase in detection probability. Additional analysis was performed to determine if prior analysis would have caused a major security or safety operating envelope issue. It was determined that a safety issue would have resulted from the prior research, but that the security may have been increased under certain conditions.

  15. Adaptive Flight Envelope Estimation and Protection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Impact Technologies, in collaboration with the Georgia Institute of Technology, proposes to develop and demonstrate an innovative flight envelope estimation and...

  16. Building Construction Elements, Building Envelope and Method for Constructing a Building Envelope

    DEFF Research Database (Denmark)

    2009-01-01

    High-strength concrete building system and method of assembly for construction a buiding envelope.......High-strength concrete building system and method of assembly for construction a buiding envelope....

  17. Torsin Mediates Primary Envelopment of Large Ribonucleoprotein Granules at the Nuclear Envelope

    Directory of Open Access Journals (Sweden)

    Vahbiz Jokhi

    2013-04-01

    Full Text Available A previously unrecognized mechanism through which large ribonucleoprotein (megaRNP granules exit the nucleus is by budding through the nuclear envelope (NE. This mechanism is akin to the nuclear egress of herpes-type viruses and is essential for proper synapse development. However, the molecular machinery required to remodel the NE during this process is unknown. Here, we identify Torsin, an AAA-ATPase that in humans is linked to dystonia, as a major mediator of primary megaRNP envelopment during NE budding. In torsin mutants, megaRNPs accumulate within the perinuclear space, and the messenger RNAs contained within fail to reach synaptic sites, preventing normal synaptic protein synthesis and thus proper synaptic bouton development. These studies begin to establish the cellular machinery underlying the exit of megaRNPs via budding, offer an explanation for the “nuclear blebbing” phenotype found in dystonia models, and provide an important link between Torsin and the synaptic phenotypes observed in dystonia.

  18. The metabolite transporters of the plastid envelope: an update.

    Directory of Open Access Journals (Sweden)

    Fabio eFacchinelli

    2011-09-01

    Full Text Available The engulfment of a photoautotrophic cyanobacterium by a primitive mitochondria-bearing eukaryote traces back to more than 1.2 billion years ago. This single endosymbiotic event not only provided the early protoalga with the metabolic capacity to perform oxygenic photosynthesis, but also introduced a plethora of other metabolic routes ranging from fatty acids and amino acids biosynthesis, nitrogen and sulfur assimilation to secondary compounds synthesis. This implicated the integration and coordination of the newly acquired metabolic entity with the host metabolism. The interface between the host cytosol and the plastidic stroma became of crucial importance in sorting precursors and products between the plastid and other cellular compartments.The plastid envelope membranes fulfill different tasks: they perform important metabolic functions, as they are involved in the synthesis of carotenoids, chlorophylls and galactolipids. In addition, since most genes of cyanobacterial origin have been transferred to the nucleus, plastidial proteins encoded by nuclear genes are post-translationally transported across the envelopes through the TIC-TOC import machinery. Most importantly, chloroplasts supply the photoautotrophic cell with photosynthates in form of reduced carbon.The innermost bilayer of the plastidic envelope represents the permeability barrier for the metabolites involved in the carbon cycle and is literally stuffed with transporter proteins facilitating their transfer. The intracellular metabolite transporters consist of polytopic proteins containing membrane spans usually in the number of four or more α-helices.Phylogenetic analyses revealed that connecting the plastid with the host metabolism was mainly a process driven by the host cell. In Arabidopsis, 58% of the metabolite transporters are of host origin, whereas only 12% are attributable to the cyanobacterial endosymbiont.This review focuses on the metabolite transporters of the inner

  19. Mosaic HIV envelope immunogenic polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  20. Comment on "The envelope of projectile trajectories"

    CERN Document Server

    Butikov, E I

    2003-01-01

    Several simple alternative methods to obtain the equation of the envelope of the family of projectile trajectories corresponding to the same initial speed are suggested, including methods in which the boundary of the region occupied by the parabolic trajectories is found as an envelope of a set of circles. Two possible generalizations of the discussed problem are also suggested. (letters and comments)

  1. 14 CFR 23.333 - Flight envelope.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight envelope. 23.333 Section 23.333... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.333 Flight envelope. (a) General. Compliance with the strength requirements of this subpart must be shown at...

  2. The epigenetics of nuclear envelope organization and disease

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, Eric C. [Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Building, Room 5.22, Edinburgh EH9 3JR (United Kingdom)], E-mail: e.schirmer@ed.ac.uk

    2008-12-01

    Mammalian chromosomes and some specific genes have non-random positions within the nucleus that are tissue-specific and heritable. Work in many organisms has shown that genes at the nuclear periphery tend to be inactive and altering their partitioning to the interior results in their activation. Proteins of the nuclear envelope can recruit chromatin with specific epigenetic marks and can also recruit silencing factors that add new epigenetic modifications to chromatin sequestered at the periphery. Together these findings indicate that the nuclear envelope is a significant epigenetic regulator. The importance of this function is emphasized by observations of aberrant distribution of peripheral heterochromatin in several human diseases linked to mutations in NE proteins. These debilitating inherited diseases range from muscular dystrophies to the premature aging progeroid syndromes and the heterochromatin changes are just one early clue for understanding the molecular details of how they work. The architecture of the nuclear envelope provides a unique environment for epigenetic regulation and as such a great deal of research will be required before we can ascertain the full range of its contributions to epigenetics.

  3. Virulence properties of the Legionella pneumophila cell envelope

    Directory of Open Access Journals (Sweden)

    Olga eShevchuk

    2011-04-01

    Full Text Available The bacterial envelope plays a crucial role in the pathogenesis of infectious diseases. In this review, we summarize the current knowledge of the structure and molecular composition of the Legionella pneumophila cell envelope. We describe LPS biosynthesis and the biological activities of membrane and periplasmic proteins and discuss their decisive functions during the pathogen-host interaction. In addition to adherence, invasion and intracellular survival of L. pneumophila, special emphasis is laid on iron acquisition, detoxification, key elicitors of the immune response and the diverse functions of outer membrane vesicles. The critical analysis of the literature reveals that the dynamics and phenotypic plasticity of the Legionella cell surface during the different metabolic stages requires more attention in the future.

  4. Seasonal benefits of a natural propolis envelope to honey bee immunity and colony health.

    Science.gov (United States)

    Borba, Renata S; Klyczek, Karen K; Mogen, Kim L; Spivak, Marla

    2015-11-01

    Honey bees, as social insects, rely on collective behavioral defenses that produce a colony-level immune phenotype, or social immunity, which in turn impacts the immune response of individuals. One behavioral defense is the collection and deposition of antimicrobial plant resins, or propolis, in the nest. We tested the effect of a naturally constructed propolis envelope within standard beekeeping equipment on the pathogen and parasite load of large field colonies, and on immune system activity, virus and storage protein levels of individual bees over the course of a year. The main effect of the propolis envelope was a decreased and more uniform baseline expression of immune genes in bees during summer and autumn months each year, compared with the immune activity in bees with no propolis envelope in the colony. The most important function of the propolis envelope may be to modulate costly immune system activity. As no differences were found in levels of bacteria, pathogens and parasites between the treatment groups, the propolis envelope may act directly on the immune system, reducing the bees' need to activate the physiologically costly production of humoral immune responses. Colonies with a natural propolis envelope had increased colony strength and vitellogenin levels after surviving the winter in one of the two years of the study, despite the fact that the biological activity of the propolis diminished over the winter. A natural propolis envelope acts as an important antimicrobial layer enshrouding the colony, benefiting individual immunity and ultimately colony health. © 2015. Published by The Company of Biologists Ltd.

  5. LINCing the nuclear envelope to gametogenesis.

    Science.gov (United States)

    Kracklauer, Martin P; Link, Jana; Alsheimer, Manfred

    2013-01-01

    Gametogenesis combines two important features: reduction of the genome content from diploid to haploid by carefully partitioning chromosomes, and the subsequent differentiation into fertilization-competent gametes, which in males is characterized by profound nuclear restructuring. These are quite difficult tasks and require a tight coordination of different cellular mechanisms. Recent studies in the field established a key role for LINC complexes in both meiosis and sperm head formation. LINC complexes comprise SUN and KASH domain proteins that form nuclear envelope (NE) bridges, linking the nucleoskeleton to the cytoskeleton. They are well known for their crucial roles in diverse cellular and developmental processes, such as nuclear positioning and cell polarization. In this review, we highlight key roles ascribed to LINC complexes and to the nucleocytoskeletal connection in gametogenesis. First, we give a short overview about the general features of LINC components and the profound reorganization of the NE in germ cells. We then focus on specific roles of LINC complexes in meiotic chromosome dynamics and their impact on pairing, synapsis, and recombination. Finally, we provide an update of the mechanisms controlling sperm head formation and discuss the role of sperm-specific LINC complexes in nuclear shaping and their relation to specialized cytoskeletal structures that form concurrently with nuclear restructuring and sperm elongation. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Safeguards Envelope Progress FY09

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf; Robert Bean

    2009-09-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters which nuclear facilities may operate within to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details advanced statistical techniques will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). As a result of the U.S. having no operating nuclear chemical reprocessing plants, there has been a strong interest in obtaining process monitoring data from the ICPP. The ICPP was shut down in 1996 and a recent effort has been made to retrieve the PM data from storage in a data mining effort. In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z- testing7.

  7. GAGE cancer-germline antigens bind DNA and are recruited to the nuclear envelope by Germ cell-less

    DEFF Research Database (Denmark)

    Gjerstorff, Morten; Rösner, Heike; Pedersen, Christina Bøg

    GAGE genes encode a highly similar, primate-specific protein family with unique primary structure and undefined roles in germ cells, various fetal cells and cancer cells. We report that GAGE proteins are intrinsically disordered proteins that provide novel interfaces between chromatin......) at the nuclear envelope. Furthermore, exogenous and endogenous GAGE proteins were recruited to the nuclear envelope in GCL-overexpressing cells. Gene expression analysis and immunohistochemical staining suggest GAGE proteins and GCL interact physiologically in human cells that express both, including male germ...... and the nuclear envelope. Structural analysis by NMR and CD spectroscopy showed GAGE proteins lack distinct secondary or tertiary structure and are therefore intrinsically disordered. In normal cells and cancer cells GAGE proteins localize predominantly in the nucleus; we found GAGE proteins formed stable...

  8. Neutralization of Zika virus by germline-like human monoclonal antibodies targeting cryptic epitopes on envelope domain III

    OpenAIRE

    Wu, Yanling; Li, Shun; Du, Lanying; Wang, Chunyu; Zou, Peng; Hong, Binbin; Yuan, Mengjiao; Ren, Xiaonan; Tai, Wanbo; Kong, Yu; Zhou, Chen; Lu, Lu; Zhou, Xiaohui; Jiang, Shibo; Ying, Tianlei

    2017-01-01

    The Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, has emerged as a global public health concern. Pre-existing cross-reactive antibodies against other flaviviruses could modulate immune responses to ZIKV infection by antibody-dependent enhancement, highlighting the importance of understanding the immunogenicity of the ZIKV envelope protein. In this study, we identified a panel of human monoclonal antibodies (mAbs) that target domain III (DIII) of the ZIKV envelope protein fr...

  9. Development of HVJ Envelope Vector and Its Application to Gene Therapy.

    Science.gov (United States)

    Kaneda, Yasufumi; Yamamoto, Seiji; Nakajima, Toshihiro

    2005-01-01

    To create a highly efficient vector system that is minimally invasive, we initially developed liposomes that contained fusion proteins from the hemagglutinating virus of Japan (HVJ; Sendai virus). These HVJ-liposomes delivered genes and drugs to cultured cells and tissues. To simplify the vector system and develop more efficient vectors, the next approach was to convert viruses to non-viral vectors. Based on this concept, we recently developed the HVJ envelope vector. HVJ with robust fusion activity was inactivated, and exogenous DNA was incorporated into the viral envelope by detergent treatment and centrifugation. The resulting HVJ envelope vector introduced plasmid DNA efficiently and rapidly into both cultured cells in vitro and organs in vivo. Furthermore, proteins, synthetic oligonucleotides, and drugs have also been effectively introduced into cells using the HVJ envelope vector. The HVJ envelope vector is a promising tool for both ex vivo and in vivo gene therapy experiments. Hearing impairment in rats was prevented and treated by hepatocyte growth factor gene transfer to cerebrospinal fluid using HVJ envelope vector. For cancer treatment, tumor-associated antigen genes were delivered efficiently to mouse dendritic cells to evoke an anti-cancer immune response. HVJ envelope vector fused dendritic cells and tumor cells and simultaneously delivered cytokine genes, such as IL-12, to the hybrid cells. This strategy successfully prevented and treated cancers in mice by stimulating the presentation of tumor antigens and the maturation of T cells. For human gene therapy, a pilot plant to commercially produce clinical grade HVJ envelope vector has been established.

  10. All the Universe in an envelope

    CERN Multimedia

    2007-01-01

    Do you know which force is hidden in an envelope or how many billions of years old are the atoms it contains? You will find the answers to these (curious) questions in a post office in the Pays de Gex. The French postal services of the Pays de Gex are again issuing pre-paid envelopes in collaboration with CERN (see Bulletin No. 24/2006). The new series presents some of the concepts of modern physics in an amazing way by showing what you can learn about the Universe with a single envelope. Packets of ten pre-stamped envelopes, each carrying a statement on fundamental physics, will be on sale from 7 July onwards. To learn more about the physics issues presented on the envelopes, people are invited to go to the CERN Web site where they will find the explanations. Five thousand envelopes will be put on sale in July and five thousand more during the French "Fête de la science" in October. They will be available from five post offices in the Pays de Gex (F...

  11. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes.

    Directory of Open Access Journals (Sweden)

    Bruno Hernáez

    2016-04-01

    Full Text Available African swine fever virus (ASFV is a nucleocytoplasmic large DNA virus (NCLDV that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs.

  12. Interaction and inhibition of dengue envelope glycoprotein with mammalian receptor DC-sign, an in-silico approach.

    Directory of Open Access Journals (Sweden)

    Masaud Shah

    Full Text Available Membrane fusion is the central molecular event during the entry of enveloped viruses into cells. The critical agents of this process are viral surface proteins, primed to facilitate cell bilayer fusion. The important role of Dendritic-cell-specific ICAM3-grabbing non-integrin (DC-SIGN in Dengue virus transmission makes it an attractive target to interfere with Dengue virus Propagation. Receptor mediated endocytosis allows the entry of virions due to the presence of endosomal membranes and low pH-induced fusion of the virus. DC-SIGN is the best characterized molecule among the candidate protein receptors and is able to mediate infection with the four serotypes of dengue virus (DENV. Unrestrained pair wise docking was used for the interaction of dengue envelope protein with DC-SIGN and monoclonal antibody 2G12. Pre-processed the PDB coordinates of dengue envelope glycoprotein and other candidate proteins were prepared and energy minimized through AMBER99 force field distributed in MOE software. Protein-protein interaction server, ZDOCK was used to find molecular interaction among the candidate proteins. Based on these interactions it was found that antibody successfully blocks the glycosylation site ASN 67 and other conserved residues present at DC-SIGN-Den-E complex interface. In order to know for certain, the exact location of the antibody in the envelope protein, co-crystallize of the envelope protein with these compounds is needed so that their exact docking locations can be identified with respect to our results.

  13. Mutational library analysis of selected amino acids in the receptor binding domain of envelope of Akv murine leukemia virus by conditionally replication competent bicistronic vectors

    DEFF Research Database (Denmark)

    Bahrami, Shervin; Jespersen, Thomas; Pedersen, Finn Skou

    2003-01-01

    The envelope protein of retroviruses is responsible for viral entry into host cells. Here, we describe a mutational library approach to dissect functional domains of the envelope protein involving a retroviral vector, which expresses both the envelope protein of Akv murine leukemia virus (MLV...... mutational library of Arg 85 and Asp 86 in the first variable region of Akv envelope protein. Homologous amino acids to Asp 86 in Moloney and Friend murine leukemia viruses are thought to be directly involved in receptor binding. Subsequent selection of mutants capable of infecting murine NIH 3T3 cells...... indicated that the wild type aspartic acid or another hydrophilic residue at position 86 is an important determinant for envelope function....

  14. Temporal control of nuclear envelope assembly by phosphorylation of lamin B receptor.

    Science.gov (United States)

    Tseng, Li-Chuan; Chen, Rey-Huei

    2011-09-01

    The nuclear envelope of metazoans disassembles during mitosis and reforms in late anaphase after sister chromatids have well separated. The coordination of these mitotic events is important for genome stability, yet the temporal control of nuclear envelope reassembly is unknown. Although the steps of nuclear formation have been extensively studied in vitro using the reconstitution system from egg extracts, the temporal control can only be studied in vivo. Here, we use time-lapse microscopy to investigate this process in living HeLa cells. We demonstrate that Cdk1 activity prevents premature nuclear envelope assembly and that phosphorylation of the inner nuclear membrane protein lamin B receptor (LBR) by Cdk1 contributes to the temporal control. We further identify a region in the nucleoplasmic domain of LBR that inhibits premature chromatin binding of the protein. We propose that this inhibitory effect is partly mediated by Cdk1 phosphorylation. Furthermore, we show that the reduced chromatin-binding ability of LBR together with Aurora B activity contributes to nuclear envelope breakdown. Our studies reveal for the first time a mechanism that controls the timing of nuclear envelope reassembly through modification of an integral nuclear membrane protein.

  15. A lamin B receptor in the nuclear envelope.

    OpenAIRE

    Worman, H.J.; Yuan, J; Blobel, G; Georgatos, S D

    1988-01-01

    Using a solution binding assay, we show that purified 125I-labeled lamin B binds in a saturable and specific fashion to lamin-depleted avian erythrocyte nuclear membranes with a Kd of approximately 0.2 microM. This binding is significantly greater than the binding of 125I-labeled lamin A and is competitively inhibited by unlabeled ligand. We demonstrate that a 58-kDa integral membrane protein (p58) is a lamin B receptor by virtue of its abundance in the nuclear envelope and association with 1...

  16. Enveloped and non-enveloped viral-like particles in Trypanosoma cruzi epimastigotes

    Science.gov (United States)

    Fernández-Presas, Ana María; Padilla-Noriega, Luis; Ingeborg-Becker; Robert, Lilia; Jiménez, José Agustín; Solano, Sandra; Delgado, Jose; Tato, Patricia; Molinari, José Luis

    2017-01-01

    ABSTRACT Electron microscopy is routinely used to identify viral infections in protozoan parasites. These viruses have been described as non-enveloped and icosahedral structures with a diameter of 30-60 nm. Most of them are classified within the non-segmented dsRNA Totiviridae family. We observed virus-like particles (VLPs) through transmission electron microscopy in the cytoplasm of Trypanosoma cruzi epimastigotes grown in cultures. Clusters of electrodense enveloped VLPs having a diameter of 48 nm were also observed. These clusters appear to have been released from distended Golgi cisternae. Furthermore, a paracrystalline array of electrodense, non-enveloped VLPs (with a diameter of 32 nm) were found in distended Golgi cisternae or as smaller clusters at a distance from the RE or Golgi. We cannot rule out that the 48 nm enveloped VLPs belong to the ssRNA Flaviviridae family because they are within its size range. The localization of enveloped VLPs is consistent with the replication strategy of these viruses that transit through the Golgi to be released at the cell surface. Due to the size and shape of the 32 nm non-enveloped VLPs, we propose that they belong to the dsRNA Totiviridae family. This is the first description of cytoplasmic enveloped and non-enveloped VLPs in T. cruzi epimastigotes. PMID:28793017

  17. Inhibition of enveloped viruses infectivity by curcumin.

    Directory of Open Access Journals (Sweden)

    Tzu-Yen Chen

    Full Text Available Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter than for the pseudorabies virus (approximately 180 nm and the vaccinia virus (roughly 335 × 200 × 200 nm. These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.

  18. Envelope Solitons in Acoustically Dispersive Vitreous Silica

    Science.gov (United States)

    Cantrell, John H.; Yost, William T.

    2012-01-01

    Acoustic radiation-induced static strains, displacements, and stresses are manifested as rectified or dc waveforms linked to the energy density of an acoustic wave or vibrational mode via the mode nonlinearity parameter of the material. An analytical model is developed for acoustically dispersive media that predicts the evolution of the energy density of an initial waveform into a series of energy solitons that generates a corresponding series of radiation-induced static strains (envelope solitons). The evolutionary characteristics of the envelope solitons are confirmed experimentally in Suprasil W1 vitreous silica. The value (-11.9 plus or minus 1.43) for the nonlinearity parameter, determined from displacement measurements of the envelope solitons via a capacitive transducer, is in good agreement with the value (-11.6 plus or minus 1.16) obtained independently from acoustic harmonic generation measurements. The agreement provides strong, quantitative evidence for the validity of the model.

  19. Computation of Phase Equilibrium and Phase Envelopes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Jørgensen, John Bagterp

    and 2) nonideal gases and liquids modeled with cubic equations of state. Next, we derive the equilibrium conditions for an isothermal-isobaric (constant temperature, constant pressure) vapor-liquid equilibrium process (PT flash), and we present a method for the computation of phase envelopes. We......In this technical report, we describe the computation of phase equilibrium and phase envelopes based on expressions for the fugacity coefficients. We derive those expressions from the residual Gibbs energy. We consider 1) ideal gases and liquids modeled with correlations from the DIPPR database...... formulate the involved equations in terms of the fugacity coefficients. We present expressions for the first-order derivatives. Such derivatives are necessary in computationally efficient gradient-based methods for solving the vapor-liquid equilibrium equations and for computing phase envelopes. Finally, we...

  20. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage....... The performance of the envelope is simulated and put through an optimization process. The impact of a design system on the architectural potential of Performance -based design was investigated.......A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  1. InduciblespyTranscription Acts as a Sensor for Envelope Stress ofSalmonella typhimurium.

    Science.gov (United States)

    Jeong, Seon Mi; Lee, Hwa Jeong; Park, Yoon Mee; Kim, Jin Seok; Lee, Sang Dae; Bang, Iel Soo

    2017-01-01

    Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella .

  2. Expression of HERV-K108 envelope interferes with HIV-1 production.

    Science.gov (United States)

    Terry, Sandra N; Manganaro, Lara; Cuesta-Dominguez, Alvaro; Brinzevich, Daria; Simon, Viviana; Mulder, Lubbertus C F

    2017-09-01

    The human endogenous retroviruses (HERV)-K of the HML-2 group include full-length or near full-length elements encoding functional proteins, and are classified as type-1 or type-2 (type-1 has a deletion in the 5' end of the env gene). Because proteins of different retroviruses can interact, we hypothesized that HERV-K envelope (Env) could influence HIV-1 replication. Here we describe the negative effect of envelope expression of certain type-2 HERV-Ks on HIV-1 production. All HIV-1 and SIV strains tested were susceptible to various degrees to inhibition by the HERV-K108 envelope. We identified four residues within HERV-K108 Env as being critical to inhibit HIV-1 production. No inhibition was observed on EGFP expression, indicating that HERV-K Env does not affect general protein production. These findings demonstrate that envelope proteins from some endogenous retroviruses can limit production of exogenous lentiviruses such as HIV-1. Future studies will elucidate the mechanism mediating HIV-1 inhibition by HERV Envs. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Deciphering the Origin and Evolution of Hepatitis B Viruses by Means of a Family of Non-enveloped Fish Viruses

    OpenAIRE

    Lauber, Chris; Seitz, Stefan; Mattei, Simone; Suh, Alexander; Beck, Jürgen; Herstein, Jennifer; Börold, Jacob; Salzburger, Walter; Kaderali, Lars; Briggs, John A. G.; Bartenschlager, Ralf

    2017-01-01

    Hepatitis B viruses (HBVs), which are enveloped viruses with reverse-transcribed DNA genomes, constitute the family Hepadnaviridae. An outstanding feature of HBVs is their streamlined genome organization with extensive gene overlap. Remarkably, the similar to 1,100 bp open reading frame (ORF) encoding the envelope proteins is fully nested within the ORF of the viral replicase P. Here, we report the discovery of a diversified family of fish viruses, designated nackednaviruses, which lack the e...

  4. Hepatitis C Virus E2 Envelope Glycoprotein Core Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Leopold; Giang, Erick; Nieusma, Travis; Kadam, Rameshwar U.; Cogburn, Kristin E.; Hua, Yuanzi; Dai, Xiaoping; Stanfield, Robyn L.; Burton, Dennis R.; Ward, Andrew B.; Wilson, Ian A.; Law, Mansun

    2014-08-26

    Hepatitis C virus (HCV), a Hepacivirus, is a major cause of viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV envelope glycoproteins E1 and E2 mediate fusion and entry into host cells and are the primary targets of the humoral immune response. The crystal structure of the E2 core bound to broadly neutralizing antibody AR3C at 2.65 angstroms reveals a compact architecture composed of a central immunoglobulin-fold β sandwich flanked by two additional protein layers. The CD81 receptor binding site was identified by electron microscopy and site-directed mutagenesis and overlaps with the AR3C epitope. The x-ray and electron microscopy E2 structures differ markedly from predictions of an extended, three-domain, class II fusion protein fold and therefore provide valuable information for HCV drug and vaccine design.

  5. Ozone Reductions Using Residential Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Sherman, Max; Nazaroff, William W.

    2009-02-01

    Ozone is an air pollutant with that can have significant health effects and a significant source of ozone in some regions of California is outdoor air. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone could lead to improved health for many California residents. Ozone is removed from indoor air by surface reactions and can also be filtered by building envelopes. The magnitude of the envelope impact depends on the specific building materials that the air flows over and the geometry of the air flow paths through the envelope that can be changes by mechanical ventilation operation. The 2008 Residential Building Standards in California include minimum requirements for mechanical ventilation by referencing ASHRAE Standard 62.2. This study examines the changes in indoor ozone depending on the mechanical ventilation system selected to meet these requirements. This study used detailed simulations of ventilation in a house to examine the impacts of different ventilation systems on indoor ozone concentrations. The simulation results showed that staying indoors reduces exposure to ozone by 80percent to 90percent, that exhaust ventilation systems lead to lower indoor ozone concentrations, that opening of windows should be avoided at times of high outdoor ozone, and that changing the time at which mechanical ventilation occurs has the ability to halve exposure to ozone. Future work should focus on the products of ozone reactions in the building envelope and the fate of these products with respect to indoor exposures.

  6. Global Envelope Tests for Spatial Processes

    DEFF Research Database (Denmark)

    Myllymäki, Mari; Mrkvička, Tomáš; Grabarnik, Pavel

    2017-01-01

    distance r only, whereas the functions are inspected on an interval of distances I. In this study, we propose two approaches related to Barnard’s Monte Carlo test for building global envelope tests on I: (1) ordering the empirical and simulated functions based on their r-wise ranks among each other, and (2...

  7. Shape Control of Responsive Building Envelopes

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning; Christensen, Jesper Thøger

    2010-01-01

    alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock-up concept of a secondary...

  8. SAFEGUARDS ENVELOPE: PREVIOUS WORK AND EXAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf; Aaron Bevill; William Charlton; Robert Bean

    2008-07-01

    The future expansion of nuclear power will require not just electricity production but fuel cycle facilities such as fuel fabrication and reprocessing plants. As large reprocessing facilities are built in various states, they must be built and operated in a manner to minimize the risk of nuclear proliferation. Process monitoring has returned to the spotlight as an added measure that can increase confidence in the safeguards of special nuclear material (SNM). Process monitoring can be demonstrated to lengthen the allowable inventory period by reducing accountancy requirements, and to reduce the false positive indications. The next logical step is the creation of a Safeguards Envelope, a set of operational parameters and models to maximize anomaly detection and inventory period by process monitoring while minimizing operator impact and false positive rates. A brief example of a rudimentary Safeguards Envelope is presented, and shown to detect synthetic diversions overlaying a measured processing plant data set. This demonstration Safeguards Envelope is shown to increase the confidence that no SNM has been diverted with minimal operator impact, even though it is based on an information sparse environment. While the foundation on which a full Safeguards Envelope can be built has been presented in historical demonstrations of process monitoring, several requirements remain yet unfulfilled. Future work will require reprocessing plant transient models, inclusion of “non-traditional” operating data, and exploration of new methods of identifying subtle events in transient processes.

  9. Discriminating Dysarthria Type from Envelope Modulation Spectra

    Science.gov (United States)

    Liss, Julie M.; LeGendre, Sue; Lotto, Andrew J.

    2010-01-01

    Purpose: Previous research demonstrated the ability of temporally based rhythm metrics to distinguish among dysarthrias with different prosodic deficit profiles (J. M. Liss et al., 2009). The authors examined whether comparable results could be obtained by an automated analysis of speech envelope modulation spectra (EMS), which quantifies the…

  10. Cytosol-dependent membrane fusion in ER, nuclear envelope and nuclear pore assembly: biological implications.

    Science.gov (United States)

    Rafikova, Elvira R; Melikov, Kamran; Chernomordik, Leonid V

    2010-01-01

    Endoplasmic reticulum and nuclear envelope rearrangements after mitosis are often studied in the reconstitution system based on Xenopus egg extract. In our recent work we partially replaced the membrane vesicles in the reconstitution mix with protein-free liposomes to explore the relative contributions of cytosolic and transmembrane proteins. Here we discuss our finding that cytosolic proteins mediate fusion between membranes lacking functional transmembrane proteins and the role of membrane fusion in endoplasmic reticulum and nuclear envelope reorganization. Cytosol-dependent liposome fusion has allowed us to restore, without adding transmembrane nucleoporins, functionality of nuclear pores, their spatial distribution and chromatin decondensation in nuclei formed at insufficient amounts of membrane material and characterized by only partial decondensation of chromatin and lack of nuclear transport. Both the mechanisms and the biological implications of the discovered coupling between spatial distribution of nuclear pores, chromatin decondensation and nuclear transport are discussed.

  11. Novel Real-Time Flight Envelope Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an aircraft flight envelope monitoring system that will provide real-time in-cockpit estimations of aircraft flight envelope boundaries,...

  12. Novel Real-Time Flight Envelope Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an aircraft flight envelope monitoring system that will provide real-time in-cockpit estimations of aircraft flight envelope boundaries....

  13. ZP genes in avian species illustrate the dynamic evolution of the vertebrate egg envelope.

    Science.gov (United States)

    Hughes, D C

    2007-01-01

    The vertebrate egg envelope is composed of a set of related proteins, encoded by the ZP genes. The apparent simplicity of the egg envelope is in contrast to the number of ZP genes identified by conventional cloning and data mining of genome sequences from a number of vertebrates. The vertebrate ZP genes fall into five classes, ZP1, ZP2, ZP3, ZPD and ZPAX. Analysis of chicken genome and EST sequence data has revealed the presence of seven distinct ZP genes, falling into these classes that are expressed in the female reproductive system. Comparison with the repertoire of ZP genes in other vertebrates suggests a major source of diversity in the composition of the egg envelope is a continual process of amplification, diversification and attrition of ZP gene sequences. Copyright 2007 S. Karger AG, Basel.

  14. Influence of the bud neck on nuclear envelope fission in Saccharomyces cerevisiae.

    Science.gov (United States)

    Melloy, Patricia G; Rose, Mark D

    2017-09-15

    Studies have shown that nuclear envelope fission (karyokinesis) in budding yeast depends on cytokinesis, but not distinguished whether this was a direct requirement, indirect, because of cell cycle arrest, or due to bud neck-localized proteins impacting both processes. To determine the requirements for karyokinesis, we examined mutants conditionally defective for bud emergence and/or nuclear migration. The common mutant phenotype was completion of the nuclear division cycle within the mother cell, but karyokinesis did not occur. In the cdc24 swe1 mutant, at the non-permissive temperature, multiple nuclei accumulated within the unbudded cell, with connected nuclear envelopes. Upon return to the permissive temperature, the cdc24 swe1 mutant initiated bud emergence, but only the nucleus spanning the neck underwent fission suggesting that the bud neck region is important for fission initiation. The neck may be critical for either mechanical reasons, as the contractile ring might facilitate fission, or for regulatory reasons, as the site of a protein network regulating nuclear envelope fission, mitotic exit, and cytokinesis. We also found that 77-85% of pairs of septin mutant nuclei completed nuclear envelope fission. In addition, 27% of myo1Δ mutant nuclei completed karyokinesis. These data suggested that fission is not dependent on mechanical contraction at the bud neck, but was instead controlled by regulatory proteins there. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. NKp44 receptor mediates interaction of the envelope glycoproteins from the West Nile and dengue viruses with NK cells.

    Science.gov (United States)

    Hershkovitz, Oren; Rosental, Benyamin; Rosenberg, Lior Ann; Navarro-Sanchez, Martha Erika; Jivov, Sergey; Zilka, Alon; Gershoni-Yahalom, Orly; Brient-Litzler, Elodie; Bedouelle, Hugues; Ho, Joanna W; Campbell, Kerry S; Rager-Zisman, Bracha; Despres, Philippe; Porgador, Angel

    2009-08-15

    Dengue virus (DV) and West Nile virus (WNV) have become a global concern due to their widespread distribution and their ability to cause a variety of human diseases. Antiviral immune defenses involve NK cells. In the present study, we investigated the interaction between NK cells and these two flaviviruses. We show that the NK-activating receptor NKp44 is involved in virally mediated NK activation through direct interaction with the flavivirus envelope protein. Recombinant NKp44 directly binds to purified DV and WNV envelope proteins and specifically to domain III of WNV envelope protein; it also binds to WNV virus-like particles. These WNV-virus-like particles and WNV-domain III of WNV envelope protein directly bind NK cells expressing high levels of NKp44. Functionally, interaction of NK cells with infective and inactivated WNV results in NKp44-mediated NK degranulation. Finally, WNV infection of cells results in increased binding of rNKp44 that is specifically inhibited by anti-WNV serum. WNV-infected target cells induce IFN-gamma secretion and augmented lysis by NKp44-expressing primary NK cells that are blocked by anti-NKp44 Abs. Our findings show that triggering of NK cells by flavivirus is mediated by interaction of NKp44 with the flavivirus envelope protein.

  16. The action of three antiseptics/disinfectants against enveloped and non-enveloped viruses.

    Science.gov (United States)

    Wood, A; Payne, D

    1998-04-01

    The antiviral action of chloroxylenol, benzalkonium chloride and cetrimide/chlorhexidine was assessed against a range of enveloped and non-enveloped human viruses using a suspension test method. Viral suspensions of 10(6)-10(7) pfu/TCID50 or sfu were prepared in each of the antiseptic/disinfectant solutions in the presence of a bovine serum/yeast extract mixture to simulate 'dirty conditions'. During incubation, aliquots were removed at predetermined timepoints up to 10 min to assess the kinetics of inactivation. Results indicate that all products were effective in inactivating the enveloped viruses herpes simplex virus type 1 and human immunodeficiency virus type 1, whilst being ineffective in inactivating human coronavirus, also enveloped, and the non-enveloped viruses. The exception to this was the benzalkonium chloride-based product (Dettol Hospital Concentrate) which was active against the non-enveloped human coxsackie virus. Four antiseptic/disinfectant solutions with chloroxylenol, benzalkonium chloride, cetrimide/chlorhexidine and povidone-iodine were also assessed for antiviral effect against human immunodeficiency virus in the presence of whole human blood. All four solutions proved to be effective within 1 min despite the cytotoxic nature of the compounds to the detection system.

  17. Communication across the bacterial cell envelope depends on the size of the periplasm.

    Directory of Open Access Journals (Sweden)

    Abir T Asmar

    2017-12-01

    Full Text Available The cell envelope of gram-negative bacteria, a structure comprising an outer (OM and an inner (IM membrane, is essential for life. The OM and the IM are separated by the periplasm, a compartment that contains the peptidoglycan. The OM is tethered to the peptidoglycan via the lipoprotein, Lpp. However, the importance of the envelope's multilayered architecture remains unknown. Here, when we removed physical coupling between the OM and the peptidoglycan, cells lost the ability to sense defects in envelope integrity. Further experiments revealed that the critical parameter for the transmission of stress signals from the envelope to the cytoplasm, where cellular behaviour is controlled, is the IM-to-OM distance. Augmenting this distance by increasing the length of the lipoprotein Lpp destroyed signalling, whereas simultaneously increasing the length of the stress-sensing lipoprotein RcsF restored signalling. Our results demonstrate the physiological importance of the size of the periplasm. They also reveal that strict control over the IM-to-OM distance is required for effective envelope surveillance and protection, suggesting that cellular architecture and the structure of transenvelope protein complexes have been evolutionarily co-optimised for correct function. Similar strategies are likely at play in cellular compartments surrounded by 2 concentric membranes, such as chloroplasts and mitochondria.

  18. Focal Targeting of the Bacterial Envelope by Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Rafi eRashid

    2016-06-01

    Full Text Available Antimicrobial peptides (AMPs are utilized by both eukaryotic and prokaryotic organisms. AMPs such as the human beta defensins, human neutrophil peptides, human cathelicidin, and many bacterial bacteriocins are cationic and capable of binding to anionic regions of the bacterial surface. Cationic AMPs (CAMPs target anionic lipids (e.g. phosphatidylglycerol (PG and cardiolipins (CL in the cell membrane and anionic components (e.g. lipopolysaccharide (LPS and lipoteichoic acid (LTA of the cell envelope. Bacteria have evolved mechanisms to modify these same targets in order to resist CAMP killing, e.g. lysinylation of PG to yield cationic lysyl-PG and alanylation of LTA. Since CAMPs offer a promising therapeutic alternative to conventional antibiotics, which are becoming less effective due to rapidly emerging antibiotic resistance, there is a strong need to improve our understanding about the AMP mechanism of action. Recent literature suggests that AMPs often interact with the bacterial cell envelope at discrete foci. Here we review recent AMP literature, with an emphasis on focal interactions with bacteria, including (1 CAMP disruption mechanisms, (2 delocalization of membrane proteins and lipids by CAMPs, and (3 CAMP sensing systems and resistance mechanisms. We conclude with new approaches for studying the bacterial membrane, e.g., lipidomics, high resolution imaging and non-detergent-based membrane domain extraction.

  19. Analysis of Building Envelope Construction in 2003 CBECS

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, David W.; Halverson, Mark A.; Jiang, Wei

    2007-06-01

    The purpose of this analysis is to determine "typical" building envelope characteristics for buildings built after 1980. We address three envelope components in this paper - roofs, walls, and window area. These typical building envelope characteristics were used in the development of DOE’s Reference Buildings .

  20. Inversion of Auditory Spectrograms, Traditional Spectrograms, and Other Envelope Representations

    DEFF Research Database (Denmark)

    Decorsière, Remi Julien Blaise; Søndergaard, Peter Lempel; MacDonald, Ewen

    2015-01-01

    Envelope representations such as the auditory or traditional spectrogram can be defined by the set of envelopes from the outputs of a filterbank. Common envelope extraction methods discard information regarding the fast fluctuations, or phase, of the signal. Thus, it is difficult to invert, or re...... to the framework is proposed, which leads to a more accurate inversion of traditional spectrograms...

  1. y Human herpesvirus 6 envelope components enriched in lipid rafts: evidence for virion-associated lipid rafts

    Directory of Open Access Journals (Sweden)

    Yamanishi Koichi

    2009-08-01

    Full Text Available Abstract In general, enveloped viruses are highly dependent on their lipid envelope for entry into host cells. Here, we demonstrated that during the course of virus maturation, a significant proportion of human herpesvirus 6 (HHV-6 envelope proteins were selectively concentrated in the detergent-resistant glycosphingolipid- and cholesterol-rich membranes (rafts in HHV-6-infected cells. In addition, the ganglioside GM1, which is known to partition preferentially into lipid rafts, was detected in purified virions, along with viral envelope glycoproteins, gH, gL, gB, gQ1, gQ2 and gO indicating that at least one raft component was included in the viral particle during the assembly process.

  2. Development of High Specific Strength Envelope Materials

    Science.gov (United States)

    Komatsu, Keiji; Sano, Masa-Aki; Kakuta, Yoshiaki

    Progress in materials technology has produced a much more durable synthetic fabric envelope for the non-rigid airship. Flexible materials are required to form airship envelopes, ballonets, load curtains, gas bags and covering rigid structures. Polybenzoxazole fiber (Zylon) and polyalirate fiber (Vectran) show high specific tensile strength, so that we developed membrane using these high specific tensile strength fibers as a load carrier. The main material developed is a Zylon or Vectran load carrier sealed internally with a polyurethane bonded inner gas retention film (EVOH). The external surface provides weather protecting with, for instance, a titanium oxide integrated polyurethane or Tedlar film. The mechanical test results show that tensile strength 1,000 N/cm is attained with weight less than 230g/m2. In addition to the mechanical properties, temperature dependence of the joint strength and solar absorptivity and emissivity of the surface are measured. 

  3. Cost Allocation and Convex Data Envelopment

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tind, Jørgen

    This paper considers allocation rules. First, we demonstrate that costs allocated by the Aumann-Shapley and the Friedman-Moulin cost allocation rules are easy to determine in practice using convex envelopment of registered cost data and parametric programming. Second, from the linear programming...... such as Data Envelopment Analysis (DEA). The convexity constraint of the BCC model introduces a non-zero slack in the objective function of the multiplier problem and we show that the cost allocation rules discussed in this paper can be used as candidates to allocate this slack value on to the input (or output......) variables and hence enable a full allocation of the inefficiency on to the input (or output) variables as in the CCR model...

  4. Envelope instability and the fourth order resonance

    Directory of Open Access Journals (Sweden)

    Chao Li

    2014-12-01

    Full Text Available The well-known envelope instability or the second order even collective mode [I. Hofmann, Phys. Rev. E 57, 4 (1998] and the fourth order resonance 4σ=360° due to the nonlinear space charge effect in high intensity beams have been studied previously. A wide stop band around 15° is found in a pure periodic focusing channel. In addition, it is illustrated that the fourth order resonance dominates over the envelope instability and practically replaces it in the stop band [D. Jeon et al., Phys. Rev. ST Accel. Beams 12, 054204 (2009]. In this paper, for a continuous beam with remarkable space charge, our 2D self-consistent particle-in-cell simulation work with the code topopic shows these two kinds of effects respectively in a periodic focusing defocusing (FD channel. For a fixed tune depression η=0.8, a stop band with a width of almost 15° is also demonstrated. Moreover, it is confirmed that analytical results of the rms envelope instability diagram are a valid tool to interpret the width of the stop band. Emittance growth rates in stop band are also well explained. It is found that, for a nearly rms matched beam, the emittance growth in the stop band is almost proportional to the saturation time of the nonlinear instability of the envelope, which happens in a quick manner and takes only a few FD cells. In contrast, the fourth order resonance is independent of rms matching and will be accompanied by beam evolution as “a long term effect” once the related mechanism is excited.

  5. Deciphering the Origin and Evolution of Hepatitis B Viruses by Means of a Family of Non-enveloped Fish Viruses.

    Science.gov (United States)

    Lauber, Chris; Seitz, Stefan; Mattei, Simone; Suh, Alexander; Beck, Jürgen; Herstein, Jennifer; Börold, Jacob; Salzburger, Walter; Kaderali, Lars; Briggs, John A G; Bartenschlager, Ralf

    2017-09-13

    Hepatitis B viruses (HBVs), which are enveloped viruses with reverse-transcribed DNA genomes, constitute the family Hepadnaviridae. An outstanding feature of HBVs is their streamlined genome organization with extensive gene overlap. Remarkably, the ∼1,100 bp open reading frame (ORF) encoding the envelope proteins is fully nested within the ORF of the viral replicase P. Here, we report the discovery of a diversified family of fish viruses, designated nackednaviruses, which lack the envelope protein gene, but otherwise exhibit key characteristics of HBVs including genome replication via protein-primed reverse-transcription and utilization of structurally related capsids. Phylogenetic reconstruction indicates that these two virus families separated more than 400 million years ago before the rise of tetrapods. We show that HBVs are of ancient origin, descending from non-enveloped progenitors in fishes. Their envelope protein gene emerged de novo, leading to a major transition in viral lifestyle, followed by co-evolution with their hosts over geologic eras. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. A new technique for quantifying temporal envelope contrasts.

    Science.gov (United States)

    Fortune, T W; Woodruff, B D; Preves, D A

    1994-02-01

    A new technique has been developed for precisely quantifying the temporal contrasts that exist between two sound samples. This technique is based on envelope subtraction, and generates an Envelope Difference Index that may be used to help clarify whether alteration of the natural speech envelope via amplification improves or degrades speech intelligibility. The Envelope Difference Index method may also be used to assess hearing aid saturation, and may have other applications as well. The technique is applicable whenever a precise quantification of the difference between two temporal envelopes is required, regardless of stimulus duration.

  7. Performance of envelope: an innovative energy system

    Directory of Open Access Journals (Sweden)

    Rossella Franchino

    2014-05-01

    Full Text Available In the field of applied research in construction, the constant request from the production's sector and the persisting both European (Directive 2010/31/EU and 2012/27/UE and national (Legislative Decree 63/13, LD 115/ 09, LD 28/11 normative indications require testing of technology solutions for envelope ever more efficient in terms of energy and the environment. The conversion of locally generated energy from renewable sources assumes a particularly important role in the energy balance of the building-plant system. In this respect, the paper illustrates the results of technological experimentation conducted within the SEEM (Solar Eco - efficient Envelope Model Project, funded in 2011 by the Ministry of Environment. The project involved the study of a combined system of solar and wind chimney, architecturally integrated into an envelope systems of the tertiary sector, in order to produce electricity and heat from renewable sources. The study proposes the performance analysis of the SEEM system's components, with particular attention to the thermo-physical relationship between the building and the integrated plant system.

  8. The cell envelope glycoconjugates of Mycobacterium tuberculosis

    Science.gov (United States)

    Angala, Shiva Kumar; Belardinelli, Juan Manuel; Huc-Claustre, Emilie; Wheat, William H.; Jackson, Mary

    2015-01-01

    Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last ten years in the discovery and development of novel inhibitors targeting their biogenesis. PMID:24915502

  9. Dynamic assembly of brambleberry mediates nuclear envelope fusion during early development.

    Science.gov (United States)

    Abrams, Elliott W; Zhang, Hong; Marlow, Florence L; Kapp, Lee; Lu, Sumei; Mullins, Mary C

    2012-08-03

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Glycosylation in HIV-1 envelope glycoprotein and its biological implications

    KAUST Repository

    Ho, Yung Shwen

    2013-08-01

    Glycosylation of HIV-1 envelope proteins (Env gp120/gp41) plays a vital role in viral evasion from the host immune response, which occurs through the masking of key neutralization epitopes and the presentation of the Env glycosylation as \\'self\\' to the host immune system. Env glycosylation is generally conserved, yet its continual evolution plays an important role in modulating viral infectivity and Env immunogenicity. Thus, it is believed that Env glycosylation, which is a vital part of the HIV-1 architecture, also controls intra- and inter-clade genetic variations. Discerning intra- and inter-clade glycosylation variations could therefore yield important information for understanding the molecular and biological differences between HIV clades and may assist in effectively designing Env-based immunogens and in clearly understanding HIV vaccines. This review provides an in-depth perspective of various aspects of Env glycosylation in the context of HIV-1 pathogenesis. © 2013 Future Medicine Ltd.

  11. Lamin B receptor: multi-tasking at the nuclear envelope.

    Science.gov (United States)

    Olins, Ada L; Rhodes, Gale; Welch, David B Mark; Zwerger, Monika; Olins, Donald E

    2010-01-01

    Lamin B receptor (LBR) is an integral membrane protein of the interphase nuclear envelope (NE). The N-terminal end resides in the nucleoplasm, binding to lamin B and heterochromatin, with the interactions disrupted during mitosis. The C-terminal end resides within the inner nuclear membrane, retreating with the ER away from condensing chromosomes during mitotic NE breakdown. Some of these properties are interpretable in terms of our current structural knowledge of LBR, but many of the structural features remain unknown. LBR apparently has an evolutionary history which brought together at least two ancient conserved structural domains (i.e., Tudor and sterol reductase). This convergence may have occurred with the emergence of the chordates and echinoderms. It is not clear what survival values have maintained LBR structure during evolution. But it seems likely that roles in post-mitotic nuclear reformation, interphase NE growth and compartmentalization of nuclear architecture might have provided some evolutionary advantage to preservation of the LBR gene.

  12. Nuclear envelope and genome interactions in cell fate

    Science.gov (United States)

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  13. Csm4-dependent telomere movement on nuclear envelope promotes meiotic recombination.

    Directory of Open Access Journals (Sweden)

    Hiromichi Kosaka

    2008-09-01

    Full Text Available During meiotic prophase, chromosomes display rapid movement, and their telomeres attach to the nuclear envelope and cluster to form a "chromosomal bouquet." Little is known about the roles of the chromosome movement and telomere clustering in this phase. In budding yeast, telomere clustering is promoted by a meiosis-specific, telomere-binding protein, Ndj1. Here, we show that a meiosis-specific protein, Csm4, which forms a complex with Ndj1, facilitates bouquet formation. In the absence of Csm4, Ndj1-bound telomeres tether to nuclear envelopes but do not cluster, suggesting that telomere clustering in the meiotic prophase consists of at least two distinct steps: Ndj1-dependent tethering to the nuclear envelope and Csm4-dependent clustering/movement. Similar to Ndj1, Csm4 is required for several distinct steps during meiotic recombination. Our results suggest that Csm4 promotes efficient second-end capture of a double-strand break following a homology search, as well as resolution of the double-Holliday junction during crossover formation. We propose that chromosome movement and associated telomere dynamics at the nuclear envelope promotes the completion of key biochemical steps during meiotic recombination.

  14. Antiviral Activity of Graphene–Silver Nanocomposites against Non-Enveloped and Enveloped Viruses

    Directory of Open Access Journals (Sweden)

    Yi-Ning Chen

    2016-04-01

    Full Text Available The discovery of novel antiviral materials is important because many infectious diseases are caused by viruses. Silver nanoparticles have demonstrated strong antiviral activity, and graphene is a potential antimicrobial material due to its large surface area, high carrier mobility, and biocompatibility. No studies on the antiviral activity of nanomaterials on non-enveloped viruses have been reported. To investigate the antiviral activity of graphene oxide (GO sheets and GO sheets with silver particles (GO-Ag against enveloped and non-enveloped viruses, feline coronavirus (FCoV with an envelope and infectious bursal disease virus (IBDV without an envelope were chosen. The morphology and sizes of GO and GO-Ag were characterized by transmission, scanning electron microscopy, and X-ray diffraction. A virus inhibition assay was used to identify the antiviral activity of GO and GO-Ag. Go-Ag inhibited 25% of infection by FCoV and 23% by IBDV, whereas GO only inhibited 16% of infection by FCoV but showed no antiviral activity against the infection by IBDV. Further application of GO and GO-Ag can be considered for personal protection equipment to decrease the transmission of viruses.

  15. NET23/STING Promotes Chromatin Compaction from the Nuclear Envelope

    Science.gov (United States)

    de las Heras, Jose I.; Saiz-Ros, Natalia; Makarov, Alexandr A.; Lazou, Vassiliki; Meinke, Peter; Waterfall, Martin; Kelly, David A.; Schirmer, Eric C.

    2014-01-01

    Changes in the peripheral distribution and amount of condensed chromatin are observed in a number of diseases linked to mutations in the lamin A protein of the nuclear envelope. We postulated that lamin A interactions with nuclear envelope transmembrane proteins (NETs) that affect chromatin structure might be altered in these diseases and so screened thirty-one NETs for those that promote chromatin compaction as determined by an increase in the number of chromatin clusters of high pixel intensity. One of these, NET23 (also called STING, MITA, MPYS, ERIS, Tmem173), strongly promoted chromatin compaction. A correlation between chromatin compaction and endogenous levels of NET23/STING was observed for a number of human cell lines, suggesting that NET23/STING may contribute generally to chromatin condensation. NET23/STING has separately been found to be involved in innate immune response signaling. Upon infection cells make a choice to either apoptose or to alter chromatin architecture to support focused expression of interferon genes and other response factors. We postulate that the chromatin compaction induced by NET23/STING may contribute to this choice because the cells expressing NET23/STING eventually apoptose, but the chromatin compaction effect is separate from this as the condensation was still observed when cells were treated with Z-VAD to block apoptosis. NET23/STING-induced compacted chromatin revealed changes in epigenetic marks including changes in histone methylation and acetylation. This indicates a previously uncharacterized nuclear role for NET23/STING potentially in both innate immune signaling and general chromatin architecture. PMID:25386906

  16. Envelope tracking CMOS power amplifier with high-speed CMOS envelope amplifier for mobile handsets

    Science.gov (United States)

    Yoshida, Eiji; Sakai, Yasufumi; Oishi, Kazuaki; Yamazaki, Hiroshi; Mori, Toshihiko; Yamaura, Shinji; Suto, Kazuo; Tanaka, Tetsu

    2014-01-01

    A high-efficiency CMOS power amplifier (PA) based on envelope tracking (ET) has been reported for a wideband code division multiple access (W-CDMA) and long term evolution (LTE) application. By adopting a high-speed CMOS envelope amplifier with current direction sensing, a 5% improvement in total power-added efficiency (PAE) and a 11 dB decrease in adjacent channel leakage ratio (ACLR) are achieved with a W-CDMA signal. Moreover, the proposed PA achieves a PAE of 25.4% for a 10 MHz LTE signal at an output power (Pout) of 25.6 dBm and a gain of 24 dB.

  17. A lamin B receptor in the nuclear envelope

    Energy Technology Data Exchange (ETDEWEB)

    Worman, H.J.; Yuan, J.; Blobel, G.; Georgatos, S.D. (Rockefeller Univ., New York, NY (USA))

    1988-11-01

    Using a solution binding assay, the authors show that purified {sup 125}I-labeled lamin B binds in a saturable and specific fashion to lamin-depleted avian erythrocyte nuclear membranes with a K{sub d} of {approx} 0.2 {mu}M. This binding is significantly greater than the binding of {sup 125}I-labeled lamin A and is competitively inhibited by unlabeled ligand. They demonstrate that a 58-kDa integral membrane protein (p58) is a lamin B receptor by virtue of its abundance in the nuclear envelope and association with {sup 125}I-labeled lamin B in ligand blotting assays. Specific antibodies raised against p58 recognize one protein in isolated nuclei and partially block {sup 125}I-labeled lamin B binding to lamin-depleted nuclear membranes. Cell fractionation and indirect immunofluorescence microscopy show that p58 is located in the periphery of the nucleus. This protein may serve as a membrane attachment site for the nuclear lamina by acting as a specific receptor for lamin B.

  18. A lamin B receptor in the nuclear envelope.

    Science.gov (United States)

    Worman, H J; Yuan, J; Blobel, G; Georgatos, S D

    1988-11-01

    Using a solution binding assay, we show that purified 125I-labeled lamin B binds in a saturable and specific fashion to lamin-depleted avian erythrocyte nuclear membranes with a Kd of approximately 0.2 microM. This binding is significantly greater than the binding of 125I-labeled lamin A and is competitively inhibited by unlabeled ligand. We demonstrate that a 58-kDa integral membrane protein (p58) is a lamin B receptor by virtue of its abundance in the nuclear envelope and association with 125I-labeled lamin B in ligand blotting assays. Specific antibodies raised against p58 recognize one protein in isolated nuclei and partially block 125I-labeled lamin B binding to lamin-depleted nuclear membranes. Cell fractionation and indirect immunofluorescence microscopy show that p58 is located in the periphery of the nucleus. This protein may serve as a membrane attachment site for the nuclear lamina by acting as a specific receptor for lamin B.

  19. Functional analysis of a novel baculovirus envelope fusion protein

    NARCIS (Netherlands)

    Westenberg, M.

    2004-01-01

    Baculoviridae are a family of large double stranded DNA viruses that are exclusively pathogenic to arthropods. Baculoviruses have been studied i) with the aim to develop alternatives to chemical pest control, ii) for their application asaneukaryotic expression system to

  20. Superresolution Microscopy of the Nuclear Envelope and Associated Proteins.

    Science.gov (United States)

    Xie, Wei; Horn, Henning F; Wright, Graham D

    2016-01-01

    Superresolution microscopy is undoubtedly one of the most exciting technologies since the invention of the optical microscope. Capable of nanometer-scale resolution to surpass the diffraction limit and coupled with the versatile labeling techniques available, it is revolutionizing the study of cell biology. Our understanding of the nucleus, the genetic and architectural center of the cell, has gained great advancements through the application of various superresolution microscopy techniques. This chapter describes detailed procedures of multichannel superresolution imaging of the mammalian nucleus, using structured illumination microscopy and single-molecule localization microscopy.

  1. Cell envelope stress responses upon protein overproduction in Bacillus subtilis

    NARCIS (Netherlands)

    Marciniak, Bogumiła Cecylia

    2012-01-01

    Bacillus subtilis wordt gebruikt in de productie van veel enzymen die nuttig zijn in de was en levensmiddelenindustrie en voor de ontwikkeling van farmaceutische producten. Ondanks eerdere verbeteringen van B. subtilis als een productiestam, door veranderingen van factoren die de verschillende

  2. Model Dust Envelopes Around Silicate Carbon Stars

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    2006-03-01

    Full Text Available We have modeled dust envelopes around silicate carbon stars using optical properties for a mixture of amorphous carbon and silicate dust grains paying close attention to the infrared observations of the stars. The 4 stars show various properties in chemistry and location of the dust shell. We expect that the objects that fit a simple detached silicate dust shell model could be in the transition phase of the stellar chemistry. For binary system objects, we find that a mixed dust chemistry model would be necessary.

  3. Back-of-the-Envelope Problems.

    Science.gov (United States)

    1987-07-01

    not a lot and... There’s a high altitude that’s above the treeline so let’s see [reduces to 1.5 million sq. miles]. Then I can figure out how many trees...problems involving physics, such as the asteroid problem mentioned above , knowledge and formulas S. -’ --. Back-of-the-envelope problems: Introduction J. L...used some subset of the methods described above , and all subjects envisioned objects. These strategies seem to be a necessary part of solving back-of

  4. Snell Envelope with Small Probability Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Del Moral, Pierre, E-mail: Pierre.Del-Moral@inria.fr; Hu, Peng, E-mail: Peng.Hu@inria.fr [Universite de Bordeaux I, Centre INRIA Bordeaux et Sud-Ouest and Institut de Mathematiques de Bordeaux (France); Oudjane, Nadia, E-mail: Nadia.Oudjane@edf.fr [EDF R and D Clamart (France)

    2012-12-15

    We present a new algorithm to compute the Snell envelope in the specific case where the criteria to optimize is associated with a small probability or a rare event. This new approach combines the Stochastic Mesh approach of Broadie and Glasserman with a particle approximation scheme based on a specific change of measure designed to concentrate the computational effort in regions pointed out by the criteria. The theoretical analysis of this new algorithm provides non asymptotic convergence estimates. Finally, the numerical tests confirm the practical interest of this approach.

  5. Cryo electron tomography of herpes simplex virus during axonal transport and secondary envelopment in primary neurons.

    Directory of Open Access Journals (Sweden)

    Iosune Ibiricu

    2011-12-01

    Full Text Available During herpes simplex virus 1 (HSV1 egress in neurons, viral particles travel from the neuronal cell body along the axon towards the synapse. Whether HSV1 particles are transported as enveloped virions as proposed by the 'married' model or as non-enveloped capsids suggested by the 'separate' model is controversial. Specific viral proteins may form a recruitment platform for microtubule motors that catalyze such transport. However, their subviral location has remained elusive. Here we established a system to analyze herpesvirus egress by cryo electron tomography. At 16 h post infection, we observed intra-axonal transport of progeny HSV1 viral particles in dissociated hippocampal neurons by live-cell fluorescence microscopy. Cryo electron tomography of frozen-hydrated neurons revealed that most egressing capsids were transported independently of the viral envelope. Unexpectedly, we found not only DNA-containing capsids (cytosolic C-capsids, but also capsids lacking DNA (cytosolic A-/B-capsids in mid-axon regions. Subvolume averaging revealed lower amounts of tegument on cytosolic A-/B-capsids than on C-capsids. Nevertheless, all capsid types underwent active axonal transport. Therefore, even few tegument proteins on the capsid vertices seemed to suffice for transport. Secondary envelopment of capsids was observed at axon terminals. On their luminal face, the enveloping vesicles were studded with typical glycoprotein-like spikes. Furthermore, we noted an accretion of tegument density at the concave cytosolic face of the vesicle membrane in close proximity to the capsids. Three-dimensional analysis revealed that these assembly sites lacked cytoskeletal elements, but that filamentous actin surrounded them and formed an assembly compartment. Our data support the 'separate model' for HSV1 egress, i.e. progeny herpes viruses being transported along axons as subassemblies and not as complete virions within transport vesicles.

  6. Pseudotyping of vesicular stomatitis virus with the envelope glycoproteins of highly pathogenic avian influenza viruses.

    Science.gov (United States)

    Zimmer, Gert; Locher, Samira; Berger Rentsch, Marianne; Halbherr, Stefan J

    2014-08-01

    Pseudotype viruses are useful for studying the envelope proteins of harmful viruses. This work describes the pseudotyping of vesicular stomatitis virus (VSV) with the envelope glycoproteins of highly pathogenic avian influenza viruses. VSV lacking the homotypic glycoprotein (G) gene (VSVΔG) was used to express haemagglutinin (HA), neuraminidase (NA) or the combination of both. Propagation-competent pseudotype viruses were only obtained when HA and NA were expressed from the same vector genome. Pseudotype viruses containing HA from different H5 clades were neutralized specifically by immune sera directed against the corresponding clade. Fast and sensitive reading of test results was achieved by vector-mediated expression of GFP. Pseudotype viruses expressing a mutant VSV matrix protein showed restricted spread in IFN-competent cells. This pseudotype system will facilitate the detection of neutralizing antibodies against virulent influenza viruses, circumventing the need for high-level biosafety containment. © 2014 The Authors.

  7. Kar5p is required for multiple functions in both inner and outer nuclear envelope fusion in Saccharomyces cerevisiae.

    Science.gov (United States)

    Rogers, Jason V; Rose, Mark D

    2014-12-02

    During mating in the budding yeast Saccharomyces cerevisiae, two haploid nuclei fuse via two sequential membrane fusion steps. SNAREs (i.e., soluble N-ethylmaleimide-sensitive factor attachment protein receptors) and Prm3p mediate outer nuclear membrane fusion, but the inner membrane fusogen remains unknown. Kar5p is a highly conserved transmembrane protein that localizes adjacent to the spindle pole body (SPB), mediates nuclear envelope fusion, and recruits Prm3p adjacent to the SPB. To separate Kar5p's functions, we tested localization, Prm3p recruitment, and nuclear fusion efficiency in various kar5 mutants. All domains and the conserved cysteine residues were essential for nuclear fusion. Several kar5 mutant proteins localized properly but did not mediate Prm3p recruitment; other kar5 mutant proteins localized and recruited Prm3p but were nevertheless defective for nuclear fusion, demonstrating additional functions beyond Prm3p recruitment. We identified one Kar5p domain required for SPB localization, which is dependent on the half-bridge protein Mps3p. Electron microscopy revealed a kar5 mutant that arrests with expanded nuclear envelope bridges, suggesting that Kar5p is required after outer nuclear envelope fusion. Finally, a split-GFP assay demonstrated that Kar5p localizes to both the inner and outer nuclear envelope. These insights suggest a mechanism by which Kar5p mediates inner nuclear membrane fusion. Copyright © 2015 Rogers and Rose.

  8. The photodissociation of CO in circumstellar envelopes

    Science.gov (United States)

    Groenewegen, M. A. T.

    2017-10-01

    Carbon monoxide is the most abundant molecule after H2 and is important for chemistry in circumstellar envelopes around late-type stars. The size of the envelope is important when modelling low-J transition lines and deriving mass-loss rates from such lines. Now that ALMA is coming to full power the extent of the CO emitting region can be measured directly for nearby asymptotic giant branch (AGB) stars. In parallel, it has become obvious in the past few years that the strength of the interstellar radiation field (ISRF) can have a significant impact on the interpretation of the emission lines. In this paper an update and extension of the classical Mamon et al. (1988, ApJ, 328, 797) paper is presented; these authors provided the CO abundance profile, described by two parameters, as a function of mass-loss rate and expansion velocity. Following recent work an improved numerical method and updated H2 and CO shielding functions are used and a larger grid is calculated that covers more parameter space, including the strength of the ISRF. The effect of changing the photodissociation radius on the low-J CO line intensities is illustrated in two cases. Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A67

  9. Groupwise Dimension Reduction via Envelope Method.

    Science.gov (United States)

    Guo, Zifang; Li, Lexin; Lu, Wenbin; Li, Bing

    2015-12-01

    The family of sufficient dimension reduction (SDR) methods that produce informative combinations of predictors, or indices, are particularly useful for high dimensional regression analysis. In many such analyses, it becomes increasingly common that there is available a priori subject knowledge of the predictors; e.g., they belong to different groups. While many recent SDR proposals have greatly expanded the scope of the methods' applicability, how to effectively incorporate the prior predictor structure information remains a challenge. In this article, we aim at dimension reduction that recovers full regression information while preserving the predictor group structure. Built upon a new concept of the direct sum envelope, we introduce a systematic way to incorporate the group information in most existing SDR estimators. As a result, the reduction outcomes are much easier to interpret. Moreover, the envelope method provides a principled way to build a variety of prior structures into dimension reduction analysis. Both simulations and real data analysis demonstrate the competent numerical performance of the new method.

  10. [Electrophysiological characterisation of envelope-following responses].

    Science.gov (United States)

    Mijares Nodarse, Eleina; Pérez Abalo, María Cecilia; Torres Fortuny, Alejandro; Vega Hernández, Mayrim

    2011-01-01

    The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. This ability is deteriorated in some neurological diseases such as multiple sclerosis, auditory neuropathy, sensorineural hearing loss, presbycusis and primary developmental language disorder. Envelope-following responses (EFRs) in humans are useful in objective measurement of temporal processing in the auditory nervous system. To evaluate EFRs in healthy younger subjects and to investigate the effects of subject states on the EFRs recorded. Eleven young subjects were included; six of them were awake and five were asleep. EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200Hz presented at 50dB HL. The EFRs we recorded were similar in all subjects. There were two principal components. During both subject sleep and wakefulness, the first component (located between 30-50Hz) was significantly larger than the second component (located between 80-110Hz). There was also a significant effect of sleep on the EFR amplitude for the modulation frequencies between 88-110, 155-165 and 190-200Hz. However, there were no significant effects of sleep on the principal EFR components. These results corroborate the usefulness of the EFR technique for objective measurement of human auditory temporal processing. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  11. A Constant Envelope OFDM Implementation on GNU Radio

    Science.gov (United States)

    2015-02-02

    Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/5524--15-9575 A Constant Envelope OFDM Implementation on GNU Radio February 2, 2015...NUMBER OF PAGES 17. LIMITATION OF ABSTRACT A Constant Envelope OFDM Implementation on GNU Radio Andrew Robertson, Amos Ajo, Sastry Kompella, Joe...time for non-linear amplification. These requirements are uniquely served by constant envelope OFDM . We describe the use-cases, theory, and

  12. Energizing the last phase of common-envelope removal

    Science.gov (United States)

    Soker, Noam

    2017-11-01

    We propose a scenario where a companion that is about to exit a common-envelope evolution (CEE) with a giant star accretes mass from the remaining envelope outside its deep orbit and launches jets that facilitate the removal of the remaining envelope. The jets that the accretion disc launches collide with the envelope and form hot bubbles that energize the envelope. Due to gravitational interaction with the envelope, which might reside in a circumbinary disc, the companion migrates farther in, but the inner boundary of the circumbinary disc continues to feed the accretion disc. While near the equatorial plane mass leaves the system at a very low velocity, along the polar directions velocities are very high. When the primary is an asymptotic giant branch star, this type of flow forms a bipolar nebula with very narrow waists. We compare this envelope-removal process with four other last-phase common-envelope-removal processes. We also note that the accreted gas from the envelope outside the orbit in the last phase of the CEE might carry with it angular momentum that is anti-aligned to the orbital angular momentum. We discuss the implications to the possibly anti-aligned spins of the merging black hole event GW170104.

  13. Nuclear envelope remnants: fluid membranes enriched in sterols and polyphosphoinositides.

    Directory of Open Access Journals (Sweden)

    Marie Garnier-Lhomme

    Full Text Available The cytoplasm of eukaryotic cells is a highly dynamic compartment where membranes readily undergo fission and fusion to reorganize the cytoplasmic architecture, and to import, export and transport various cargos within the cell. The double membrane of the nuclear envelope that surrounds the nucleus, segregates the chromosomes from cytoplasm and regulates nucleocytoplasmic transport through pores. Many details of its formation are still unclear. At fertilization the sperm devoid of nuclear envelope pores enters the egg. Although most of the sperm nuclear envelope disassembles, remnants of the envelope at the acrosomal and centriolar fossae do not and are subsequently incorporated into the newly forming male pronuclear envelope. Remnants are conserved from annelid to mammalian sperm.Using lipid mass spectrometry and a new application of deuterium solid-state NMR spectroscopy we have characterized the lipid composition and membrane dynamics of the sperm nuclear envelope remnants in isolated sperm nuclei.We report nuclear envelope remnants are relatively fluid membranes rich in sterols, devoid of sphingomyelin, and highly enriched in polyphosphoinositides and polyunsaturated phospholipids. The localization of the polybasic effector domain of MARCKS illustrates the non-nuclear aspect of the polyphosphoinositides. Based on their atypical biophysical characteristics and phospholipid composition, we suggest a possible role for nuclear envelope remnants in membrane fusion leading to nuclear envelope assembly.

  14. Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael

    This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown infinitedime......This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

  15. Sorting nexin 6 enhances lamin a synthesis and incorporation into the nuclear envelope.

    Directory of Open Access Journals (Sweden)

    Jose M González-Granado

    Full Text Available Nuclear lamins are important structural and functional proteins in mammalian cells, but little is known about the mechanisms and cofactors that regulate their traffic into the nucleus. Here, we demonstrate that trafficking of lamin A, but not lamin B1, and its assembly into the nuclear envelope are regulated by sorting nexin 6 (SNX6, a major component of the retromer that targets proteins and other molecules to specific subcellular locations. SNX6 interacts with lamin A in vitro and in vivo and links it to the outer surface of the endoplasmic reticulum in human and mouse cells. SNX6 transports its lamin A cargo to the nuclear envelope in a process that takes several hours. Lamin A protein levels in the nucleus augment or decrease, respectively, upon gain or loss of SNX6 function. We further show that SNX6-dependent lamin A nuclear import occurs across the nuclear pore complex via a RAN-GTP-dependent mechanism. These results identify SNX6 as a key regulator of lamin A synthesis and incorporation into the nuclear envelope.

  16. Sorting Nexin 6 Enhances Lamin A Synthesis and Incorporation into the Nuclear Envelope

    Science.gov (United States)

    González-Granado, Jose M.; Navarro-Puche, Ana; Molina-Sanchez, Pedro; Blanco-Berrocal, Marta; Viana, Rosa; de Mora, Jaime Font; Andrés, Vicente

    2014-01-01

    Nuclear lamins are important structural and functional proteins in mammalian cells, but little is known about the mechanisms and cofactors that regulate their traffic into the nucleus. Here, we demonstrate that trafficking of lamin A, but not lamin B1, and its assembly into the nuclear envelope are regulated by sorting nexin 6 (SNX6), a major component of the retromer that targets proteins and other molecules to specific subcellular locations. SNX6 interacts with lamin A in vitro and in vivo and links it to the outer surface of the endoplasmic reticulum in human and mouse cells. SNX6 transports its lamin A cargo to the nuclear envelope in a process that takes several hours. Lamin A protein levels in the nucleus augment or decrease, respectively, upon gain or loss of SNX6 function. We further show that SNX6-dependent lamin A nuclear import occurs across the nuclear pore complex via a RAN-GTP-dependent mechanism. These results identify SNX6 as a key regulator of lamin A synthesis and incorporation into the nuclear envelope. PMID:25535984

  17. The plant nuclear envelope and regulation of gene expression.

    Science.gov (United States)

    Parry, Geraint

    2015-03-01

    The nuclear envelope (NE) separates the key mechanisms of transcription and translation, and as such is a critical control point in all eukaryotic cells. In plants, the proteins of the NE influence a number of processes including the control of nucleo-cytoplasmic transport of RNA and protein, chromatin localization to the nuclear periphery, and direct chromatin binding by members of the nuclear pore complex (NPC). In this review I attempt to bring these roles under the umbrella of their effect on gene expression, even though the complex nature of this cellular environment means there is considerable overlap of effects. Although the volume of research in plant cells has greatly improved over recent years, it is clear that our understanding of how the components of the NE either directly or indirectly influence gene expression is still in its infancy. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. The Primary Enveloped Virion of Herpes Simplex Virus 1: Its Role in Nuclear Egress.

    Science.gov (United States)

    Newcomb, William W; Fontana, Juan; Winkler, Dennis C; Cheng, Naiqian; Heymann, J Bernard; Steven, Alasdair C

    2017-06-13

    Many viruses migrate between different cellular compartments for successive stages of assembly. The HSV-1 capsid assembles in the nucleus and then transfers into the cytoplasm. First, the capsid buds through the inner nuclear membrane, becoming coated with nuclear egress complex (NEC) protein. This yields a primary enveloped virion (PEV) whose envelope fuses with the outer nuclear membrane, releasing the capsid into the cytoplasm. We investigated the associated molecular mechanisms by isolating PEVs from US3-null-infected cells and imaging them by cryo-electron microscopy and tomography. (pUS3 is a viral protein kinase in whose absence PEVs accumulate in the perinuclear space.) Unlike mature extracellular virions, PEVs have very few glycoprotein spikes. PEVs are ~20% smaller than mature virions, and the little space available between the capsid and the NEC layer suggests that most tegument proteins are acquired later in the egress pathway. Previous studies have proposed that NEC is organized as hexamers in honeycomb arrays in PEVs, but we find arrays of heptameric rings in extracts from US3-null-infected cells. In a PEV, NEC contacts the capsid predominantly via the pUL17/pUL25 complexes which are located close to the capsid vertices. Finally, the NEC layer dissociates from the capsid as it leaves the nucleus, possibly in response to pUS3-mediated phosphorylation. Overall, nuclear egress emerges as a process driven by a program of multiple weak interactions. IMPORTANCE On its maturation pathway, the newly formed HSV-1 nucleocapsid must traverse the nuclear envelope, while respecting the integrity of that barrier. Nucleocapsids (125 nm in diameter) are too large to pass through the nuclear pore complexes that conduct most nucleocytoplasmic traffic. It is now widely accepted that the process involves envelopment/de-envelopment of a key intermediate-the primary enveloped virion. In wild-type infections, PEVs are short-lived, which has impeded study. Using a mutant

  19. Isolation and characterization of 20'-F-RNA aptamers against whole HIV-1 subtype C envelope pseudovirus

    CSIR Research Space (South Africa)

    London, GM

    2015-01-01

    Full Text Available , with a view to target surface molecules that facilitate infection, such as the envelope protein, in their native form. HIV-1(subCAP45) belongs to subtype C viruses endemic in Sub-Saharan Africa and responsible for the majority of the global HIV-1...

  20. Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

    Directory of Open Access Journals (Sweden)

    Vinca Icard

    Full Text Available The density of circulating hepatitis C virus (HCV particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB positive and triglyceride rich lipoproteins (TRL likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1-E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed.

  1. Remodeling of the Nuclear Envelope and Lamina during Bovine Preimplantation Development and Its Functional Implications.

    Directory of Open Access Journals (Sweden)

    Jens Popken

    Full Text Available The present study demonstrates a major remodeling of the nuclear envelope and its underlying lamina during bovine preimplantation development. Up to the onset of major embryonic genome activation (MGA at the 8-cell stage nuclei showed a non-uniform distribution of nuclear pore complexes (NPCs. NPCs were exclusively present at sites where DNA contacted the nuclear lamina. Extended regions of the lamina, which were not contacted by DNA, lacked NPCs. In post-MGA nuclei the whole lamina was contacted rather uniformly by DNA. Accordingly, NPCs became uniformly distributed throughout the entire nuclear envelope. These findings shed new light on the conditions which control the integration of NPCs into the nuclear envelope. The switch from maternal to embryonic production of mRNAs was accompanied by multiple invaginations covered with NPCs, which may serve the increased demands of mRNA export and protein import. Other invaginations, as well as interior nuclear segments and vesicles without contact to the nuclear envelope, were exclusively positive for lamin B. Since the abundance of these invaginations and vesicles increased in concert with a massive nuclear volume reduction, we suggest that they reflect a mechanism for fitting the nuclear envelope and its lamina to a shrinking nuclear size during bovine preimplantation development. In addition, a deposit of extranuclear clusters of NUP153 (a marker for NPCs without associated lamin B was frequently observed from the zygote stage up to MGA. Corresponding RNA-Seq data revealed deposits of spliced, maternally provided NUP153 mRNA and little unspliced, newly synthesized RNA prior to MGA, which increased strongly at the initiation of embryonic expression of NUP153 at MGA.

  2. Fullerenes and fulleranes in circumstellar envelopes

    Science.gov (United States)

    Zhang, Yong; Kwok, Sun; Sadjadi, SeyedAbdolreza

    2016-07-01

    Three decades of search have recently led to convincing discoveries of cosmic fullerenes. The presence of C60 and C+ 60 in both circumstellar and interstellar environments suggests that these molecules and their derivatives can be efficiently formed in circumstellar envelopes and survive in harsh conditions. Detailed analysis of the infrared bands from fullerenes and their connections with the local properties can provide valuable information on the physical conditions and chemical processes that occurred in the late stages of stellar evolution. The identification of C+ 60 as the carrier of four diffuse interstellar bands (DIBs) suggests that fullerene- related compounds are abundant in interstellar space and are essential for resolving the DIB mystery. Experiments have revealed a high hydrogenation rate when C60 is exposed to atomic hydrogen, motivating the attempt to search for cosmic fulleranes. In this paper, we present a short review of current knowledge of cosmic fullerenes and fulleranes and briefly discuss the implications on circumstellar chemistry.

  3. Integrated Energy Design of the Building Envelope

    DEFF Research Database (Denmark)

    Nielsen, Martin Vraa

    This thesis describes the outcome of the PhD project Integrated energy design of the building envelope carried out through a combination of scientific dissemination reported through peer-reviewed journals and a wide range of affiliated projects involved in at an architectural firm. The research...... project analysed how the implementation of technical knowledge early in the building design process can quantify the effect of a building’s façades on its energy efficiency and indoor climate and thereby facilitate a more qualified design development. The project was structured in the following way: 1...... place. This was done by applying the methodology of Integrated Energy Design (IED) and analysing its applicability in the design of façades. A major part of the project was an actual engagement in the architectural process to test out incorporating a consciousness about energy and comfort as part...

  4. Evaluating Emergency Physicians: Data Envelopment Analysis Approach

    Science.gov (United States)

    Fiallos, Javier; Farion, Ken; Michalowski, Wojtek; Patrick, Jonathan

    2013-01-01

    The purpose of this research is to develop an evaluation tool to assess performance of Emergency Physicians according to such criteria as resource utilization, patient throughput and the quality of care. Evaluation is conducted using a mathematical programming model known as Data Envelopment Analysis (DEA). Use of this model does not require the subjective assignment of weights associated with each criterion – a feature typical of methodologies that rely on composite scores. The DEA model presented in this paper was developed using a hypothetical data set describing a representative set of profiles of Emergency Physicians. The solution to the model relates the performance of each Emergency Physician in relation to the others and to a benchmark. We discuss how such an evaluation tool can be used in practice. PMID:24551348

  5. Evaluating emergency physicians: data envelopment analysis approach.

    Science.gov (United States)

    Fiallos, Javier; Farion, Ken; Michalowski, Wojtek; Patrick, Jonathan

    2013-01-01

    The purpose of this research is to develop an evaluation tool to assess performance of Emergency Physicians according to such criteria as resource utilization, patient throughput and the quality of care. Evaluation is conducted using a mathematical programming model known as Data Envelopment Analysis (DEA). Use of this model does not require the subjective assignment of weights associated with each criterion - a feature typical of methodologies that rely on composite scores. The DEA model presented in this paper was developed using a hypothetical data set describing a representative set of profiles of Emergency Physicians. The solution to the model relates the performance of each Emergency Physician in relation to the others and to a benchmark. We discuss how such an evaluation tool can be used in practice.

  6. Enveloping branes and brane-world singularities

    CERN Document Server

    Antoniadis, Ignatios; Klaoudatou, Ifigeneia

    2014-01-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows to determine the singularity structure of the solutions. The result is applied to braneworlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parametrizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite distance singularity contrary to previous claims. We then study the possibility of avoiding finite distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes however this possibility, as well.

  7. Enveloping branes and brane-world singularities.

    Science.gov (United States)

    Antoniadis, Ignatios; Cotsakis, Spiros; Klaoudatou, Ifigeneia

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well.

  8. Enveloping branes and brane-world singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios; Cotsakis, Spiros [CERN-Theory Division, Department of Physics, Geneva 23 (Switzerland); Klaoudatou, Ifigeneia [University of the Aegean, Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, Samos (Greece)

    2014-12-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well. (orig.)

  9. Performance measurement with fuzzy data envelopment analysis

    CERN Document Server

    Tavana, Madjid

    2014-01-01

    The intensity of global competition and ever-increasing economic uncertainties has led organizations to search for more efficient and effective ways to manage their business operations.  Data envelopment analysis (DEA) has been widely used as a conceptually simple yet powerful tool for evaluating organizational productivity and performance. Fuzzy DEA (FDEA) is a promising extension of the conventional DEA proposed for dealing with imprecise and ambiguous data in performance measurement problems. This book is the first volume in the literature to present the state-of-the-art developments and applications of FDEA. It is designed for students, educators, researchers, consultants and practicing managers in business, industry, and government with a basic understanding of the DEA and fuzzy logic concepts.

  10. ASYMMETRIC ACCRETION FLOWS WITHIN A COMMON ENVELOPE

    Energy Technology Data Exchange (ETDEWEB)

    MacLeod, Morgan; Ramirez-Ruiz, Enrico [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2015-04-10

    This paper examines flows in the immediate vicinity of stars and compact objects dynamically inspiralling within a common envelope (CE). Flow in the vicinity of the embedded object is gravitationally focused, leading to drag and potentially to gas accretion. This process has been studied numerically and analytically in the context of Hoyle–Lyttleton accretion (HLA). Yet, within a CE, accretion structures may span a large fraction of the envelope radius, and in so doing sweep across a substantial radial gradient of density. We quantify these gradients using detailed stellar evolution models for a range of CE encounters. We provide estimates of typical scales in CE encounters that involve main sequence stars, white dwarfs, neutron stars, and black holes with giant-branch companions of a wide range of masses. We apply these typical scales to hydrodynamic simulations of three-dimensional HLA with an upstream density gradient. This density gradient breaks the symmetry that defines HLA flow, and imposes an angular momentum barrier to accretion. Material that is focused into the vicinity of the embedded object thus may not be able to accrete. As a result, accretion rates drop dramatically, by one to two orders of magnitude, while drag rates are only mildly affected. We provide fitting formulae to the numerically derived rates of drag and accretion as a function of the density gradient. The reduced ratio of accretion to drag suggests that objects that can efficiently gain mass during CE evolution, such as black holes and neutron stars, may grow less than implied by the HLA formalism.

  11. Studies of inactivation mechanism of non-enveloped icosahedral virus by a visible ultrashort pulsed laser.

    Science.gov (United States)

    Tsen, Shaw-Wei D; Kingsley, David H; Poweleit, Christian; Achilefu, Samuel; Soroka, Douglas S; Wu, T C; Tsen, Kong-Thon

    2014-02-05

    Low-power ultrashort pulsed (USP) lasers operating at wavelengths of 425 nm and near infrared region have been shown to effectively inactivate viruses such as human immunodeficiency virus (HIV), M13 bacteriophage, and murine cytomegalovirus (MCMV). It was shown previously that non-enveloped, helical viruses such as M13 bacteriophage, were inactivated by a USP laser through an impulsive stimulated Raman scattering (ISRS) process. Recently, enveloped virus like MCMV has been shown to be inactivated by a USP laser via protein aggregation induced by an ISRS process. However, the inactivation mechanism for a clinically important class of viruses--non-enveloped, icosahedral viruses remains unknown. We have ruled out the following four possible inactivation mechanisms for non-enveloped, icosahedral viruses, namely, (1) inactivation due to ultraviolet C (UVC) photons produced by non-linear optical process of the intense, fundamental laser beam at 425 nm; (2) inactivation caused by thermal heating generated by the direct laser absorption/heating of the virion; (3) inactivation resulting from a one-photon absorption process via chromophores such as porphyrin molecules, or indicator dyes, potentially producing reactive oxygen or other species; (4) inactivation by the USP lasers in which the extremely intense laser pulse produces shock wave-like vibrations upon impact with the viral particle. We present data which support that the inactivation mechanism for non-enveloped, icosahedral viruses is the impulsive stimulated Raman scattering process. Real-time PCR experiments show that, within the amplicon size of 273 bp tested, there is no damage on the genome of MNV-1 caused by the USP laser irradiation. We conclude that our model non-enveloped virus, MNV-1, is inactivated by the ISRS process. These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales. From the analysis of the transmission electron microscope (TEM) images of viral particles

  12. Studies of inactivation mechanism of non-enveloped icosahedral virus by a visible ultrashort pulsed laser

    Science.gov (United States)

    2014-01-01

    Background Low-power ultrashort pulsed (USP) lasers operating at wavelengths of 425 nm and near infrared region have been shown to effectively inactivate viruses such as human immunodeficiency virus (HIV), M13 bacteriophage, and murine cytomegalovirus (MCMV). It was shown previously that non-enveloped, helical viruses such as M13 bacteriophage, were inactivated by a USP laser through an impulsive stimulated Raman scattering (ISRS) process. Recently, enveloped virus like MCMV has been shown to be inactivated by a USP laser via protein aggregation induced by an ISRS process. However, the inactivation mechanism for a clinically important class of viruses – non-enveloped, icosahedral viruses remains unknown. Results and discussions We have ruled out the following four possible inactivation mechanisms for non-enveloped, icosahedral viruses, namely, (1) inactivation due to ultraviolet C (UVC) photons produced by non-linear optical process of the intense, fundamental laser beam at 425 nm; (2) inactivation caused by thermal heating generated by the direct laser absorption/heating of the virion; (3) inactivation resulting from a one-photon absorption process via chromophores such as porphyrin molecules, or indicator dyes, potentially producing reactive oxygen or other species; (4) inactivation by the USP lasers in which the extremely intense laser pulse produces shock wave-like vibrations upon impact with the viral particle. We present data which support that the inactivation mechanism for non-enveloped, icosahedral viruses is the impulsive stimulated Raman scattering process. Real-time PCR experiments show that, within the amplicon size of 273 bp tested, there is no damage on the genome of MNV-1 caused by the USP laser irradiation. Conclusion We conclude that our model non-enveloped virus, MNV-1, is inactivated by the ISRS process. These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales. From the analysis of the transmission

  13. 5-(Perylen-3-yl)ethynyl-arabino-uridine (aUY11), an arabino-based rigid amphipathic fusion inhibitor, targets virion envelope lipids to inhibit fusion of influenza virus, hepatitis C virus, and other enveloped viruses.

    Science.gov (United States)

    Colpitts, Che C; Ustinov, Alexey V; Epand, Raquel F; Epand, Richard M; Korshun, Vladimir A; Schang, Luis M

    2013-04-01

    Entry of enveloped viruses requires fusion of viral and cellular membranes. Fusion requires the formation of an intermediate stalk structure, in which only the outer leaflets are fused. The stalk structure, in turn, requires the lipid bilayer of the envelope to bend into negative curvature. This process is inhibited by enrichment in the outer leaflet of lipids with larger polar headgroups, which favor positive curvature. Accordingly, phospholipids with such shape inhibit viral fusion. We previously identified a compound, 5-(perylen-3-yl)ethynyl-2'-deoxy-uridine (dUY11), with overall shape and amphipathicity similar to those of these phospholipids. dUY11 inhibited the formation of the negative curvature necessary for stalk formation and the fusion of a model enveloped virus, vesicular stomatitis virus (VSV). We proposed that dUY11 acted by biophysical mechanisms as a result of its shape and amphipathicity. To test this model, we have now characterized the mechanisms against influenza virus and HCV of 5-(perylen-3-yl)ethynyl-arabino-uridine (aUY11), which has shape and amphipathicity similar to those of dUY11 but contains an arabino-nucleoside. aUY11 interacted with envelope lipids to inhibit the infectivity of influenza virus, hepatitis C virus (HCV), herpes simplex virus 1 and 2 (HSV-1/2), and other enveloped viruses. It specifically inhibited the fusion of influenza virus, HCV, VSV, and even protein-free liposomes to cells. Furthermore, aUY11 inhibited the formation of negative curvature in model lipid bilayers. In summary, the arabino-derived aUY11 and the deoxy-derived dUY11 act by the same antiviral mechanisms against several enveloped but otherwise unrelated viruses. Therefore, chemically unrelated compounds of appropriate shape and amphipathicity target virion envelope lipids to inhibit formation of the negative curvature required for fusion, inhibiting infectivity by biophysical, not biochemical, mechanisms.

  14. Calculation of CWKB envelope in boson and fermion productions

    Indian Academy of Sciences (India)

    We present the calculation of envelope of boson and of both low- and high- mass fermion production at the end of inflation when the coherently oscillating inflatons decay into bosons and fermions. We consider three different models of inflation and use CWKB technique to calculate the envelope to understand the structure ...

  15. Calculation of CWKB envelope in boson and fermion productions

    Indian Academy of Sciences (India)

    Abstract. We present the calculation of envelope of boson and of both low- and high- mass fermion production at the end of inflation when the coherently oscillating inflatons decay into bosons and fermions. We consider three different models of inflation and use. CWKB technique to calculate the envelope to understand the ...

  16. Mauritius green building handbook, vol 1: Building envelope

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available The building envelope plays a significant role in the performance of a building, especially with regard to the green building components. This chapter will focus on the external building envelope only, i.e., sub-structure, super structure, and roof...

  17. Modeling Protostar Envelopes and Disks Seen With ALMA

    Science.gov (United States)

    Terebey, Susan; Flores-Rivera, Lizxandra; Willacy, Karen

    2017-01-01

    Thermal continuum emission from protostars comes from both the envelope and circumstellar disk. The dust emits on a variety of spatial scales, ranging from sub-arcseconds for disks to roughly 10 arcseconds for envelopes for nearby protostars. We present models of what ALMA should detect that incorporate a self-consistent collapse solution, radiative transfer, and realistic dust properties.

  18. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.

    Science.gov (United States)

    Liu, Guan-Ting; Kung, Hsiu-Ni; Chen, Chung-Kuan; Huang, Cheng; Wang, Yung-Li; Yu, Cheng-Pu; Lee, Chung-Pei

    2018-02-26

    Although a vesicular nucleocytoplasmic transport system is believed to exist in eukaryotic cells, the features of this pathway are mostly unknown. Here, we report that the BFRF1 protein of the Epstein-Barr virus improves vesicular transport of nuclear envelope (NE) to facilitate the translocation and clearance of nuclear components. BFRF1 expression induces vesicles that selectively transport nuclear components to the cytoplasm. With the use of aggregation-prone proteins as tools, we found that aggregated nuclear proteins are dispersed when these BFRF1-induced vesicles are formed. BFRF1-containing vesicles engulf the NE-associated aggregates, exit through from the NE, and putatively fuse with autophagic vacuoles. Chemical treatment and genetic ablation of autophagy-related factors indicate that autophagosome formation and autophagy-linked FYVE protein-mediated autophagic proteolysis are involved in this selective clearance of nuclear proteins. Remarkably, vesicular transport, elicited by BFRF1, also attenuated nuclear aggregates accumulated in neuroblastoma cells. Accordingly, induction of NE-derived vesicles by BFRF1 facilitates nuclear protein translocation and clearance, suggesting that autophagy-coupled transport of nucleus-derived vesicles can be elicited for nuclear component catabolism in mammalian cells.-Liu, G.-T., Kung, H.-N., Chen, C.-K., Huang, C., Wang, Y.-L., Yu, C.-P., Lee, C.-P. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.

  19. Design reference year for development of photovoltaic envelope systems

    Science.gov (United States)

    Mihalka, Peter; Matiasovsky, Peter

    2017-07-01

    An application of photovoltaic cells on external surfaces of building envelope represents a development of new construction element. A mutual coupling between thermal behaviour of photovoltaic layer and the other layers of the structure, with special properties, requires a specific selection of the characteristic outdoor thermal boundary conditions, necessary for optimum design of the envelope from the aspect of structure, material composition and geometry. The main design criteria are the effectiveness and elimination of overheating of photovoltaic module and the optimisation of heat distribution in the envelope structure during particular year seasons. The paper contains the results of the analysis of time courses of climatic elements during a real year as the boundary conditions for simulation of photovoltaic integrated building envelope systems, used in simulations of thermal behaviour of photovoltaics integrated with building envelope systems.

  20. A Spectral Algorithm for Envelope Reduction of Sparse Matrices

    Science.gov (United States)

    Barnard, Stephen T.; Pothen, Alex; Simon, Horst D.

    1993-01-01

    The problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope-reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2-sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reordering algorithm usually computes smaller envelope sizes than those obtained from the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK reverse Cuthill-McKee (RCM), in some cases reducing the envelope by more than a factor of two.

  1. HIV envelope glycoprotein imaged at high resolution | Center for Cancer Research

    Science.gov (United States)

    The outer surface of the human immunodeficiency virus (HIV) is surrounded by an envelope studded with spike-shaped glycoproteins called Env that help the deadly virus identify, bind, and infect cells. When unbound, Env exists in a “closed” conformational state. Upon binding with target cells, such as CD4+ T cells, the protein transitions to an “open” configuration. Given that Env is the only viral protein expressed on HIV’s surface, knowing its detailed structure—especially in the unbound state—may be critical for designing antibodies and vaccines against HIV.

  2. Requirement of cholesterol in the viral envelope for dengue virus infection.

    Science.gov (United States)

    Carro, Ana C; Damonte, Elsa B

    2013-06-01

    The role of cholesterol in the virus envelope or in the cellular membranes for dengue virus (DENV) infection was examined by depletion with methyl-beta-cyclodextrin (MCD) or nystatin. Pretreatment of virions with MCD or nystatin significantly reduced virus infectivity in a dose-dependent manner. By contrast, pre-treatment of diverse human cell lines with MCD or nystatin did not affect DENV infection. The four DENV serotypes were similarly inactivated by cholesterol-extracting drugs and infectivity was partially rescued when virion suspensions were treated with MCD in the presence of bovine serum. The addition of serum or exogenous water-soluble cholesterol after MCD treatment did not produce a reversion of MCD inactivating effect. Furthermore, virion treatment with extra cholesterol exerted also a virucidal effect. Binding and uptake of cholesterol-deficient DENV into the host cell were not impaired, whereas the next step of fusion between virion envelope and endosome membrane leading to virion uncoating and release of nucleocapsids to the cytoplasm appeared to be prevented, as determined by the retention of capsid protein in cells infected with MCD inactivated-DENV virions. Thereafter, the infection was almost completely inhibited, given the failure of viral RNA synthesis and viral protein expression in cells infected with MCD-treated virions. These data suggest that envelope cholesterol is a critical factor in the fusion process for DENV entry. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Membrane topology analysis of HIV-1 envelope glycoprotein gp41

    Directory of Open Access Journals (Sweden)

    Xiao Dan

    2010-11-01

    Full Text Available Abstract Background The gp41 subunit of the HIV-1 envelope glycoprotein (Env has been widely regarded as a type I transmembrane protein with a single membrane-spanning domain (MSD. An alternative topology model suggested multiple MSDs. The major discrepancy between the two models is that the cytoplasmic Kennedy sequence in the single MSD model is assigned as the extracellular loop accessible to neutralizing antibodies in the other model. We examined the membrane topology of the gp41 subunit in both prokaryotic and mammalian systems. We attached topological markers to the C-termini of serially truncated gp41. In the prokaryotic system, we utilized a green fluorescent protein (GFP that is only active in the cytoplasm. The tag protein (HaloTag and a membrane-impermeable ligand specific to HaloTag was used in the mammalian system. Results In the absence of membrane fusion, both the prokaryotic and mammalian systems (293FT cells supported the single MSD model. In the presence of membrane fusion in mammalian cells (293CD4 cells, the data obtained seem to support the multiple MSD model. However, the region predicted to be a potential MSD is the highly hydrophilic Kennedy sequence and is least likely to become a MSD based on several algorithms. Further analysis revealed the induction of membrane permeability during membrane fusion, allowing the membrane-impermeable ligand and antibodies to cross the membrane. Therefore, we cannot completely rule out the possible artifacts. Addition of membrane fusion inhibitors or alterations of the MSD sequence decreased the induction of membrane permeability. Conclusions It is likely that a single MSD model for HIV-1 gp41 holds true even in the presence of membrane fusion. The degree of the augmentation of membrane permeability we observed was dependent on the membrane fusion and sequence of the MSD.

  4. HVJ envelope vector, a versatile delivery system: its development, application, and perspectives.

    Science.gov (United States)

    Zhang, Qingxian; Li, Ying; Shi, Yonghong; Zhang, Yanling

    2008-08-29

    An efficient and minimally invasive vector system is the "bottle neck" of both gene transfer and drug delivery. Numerous viral and non-viral (synthetic) delivery systems have been developed and improved. Hemagglutinating virus of Japan (HVJ, Sendai virus) envelope vector is a novel and unique system which combined the advantages of viral and non-viral vectors with the following features and advantages: (1) safe and easy as a "non-viral" transfection reagent; (2) delivery of various molecules including plasmid DNA, siRNA, protein, antisense oligonucleotide; (3) wide usability from in vitro to in vivo. In this review, the development, application, and perspectives of the HVJ envelope vector will be discussed.

  5. Understanding three-dimensional damage envelopes

    Science.gov (United States)

    Browning, John; Harland, Sophie; Meredith, Philip; Healy, David; Mitchell, Tom

    2017-04-01

    Microcrack damage leading to failure in rocks evolves in response to differential loading. This loading is often visualized in a two-dimensional stress space through the use of Mohr-Coulomb diagrams. The vast majority of experimental studies investigate damage evolution and rock failure using conventional triaxial stress states (σ1 > σ2 = σ3) in which the results can be easily represented in a Mohr-Coulomb plot. However, in nature the stress state is in general truly triaxial (σ1 > σ2 > σ3) and as such comprises a 3D stress state potentially leading to more complexity. By monitoring acoustic wave velocities and acoustic emissions we have shown that damage is generated in multiple orientations depending on the loading directions and hence principal stress directions. Furthermore, crack growth is shown to be a function of differential stress regardless of the mean stress. As such, new cracks can form due to a decrease in the minimum principal stress, which reduces mean stress but increases the differential stress. Although the size of individual cracks is not affected by the intermediate principal stress it has been shown that the σ2 plays a key role in suppressing the total amount of crack growth and concentrates this damage in a single plane. Hence, the differential stress at which rocks fail (i.e. the rock strength) will be significantly increased under true triaxial stress conditions than under the much more commonly applied condition of conventional triaxial stress. Through a series of cyclic loading tests we investigated the Kaiser effect, we show that while individual stress states are important, the stress path by which this stress state is reached is equally important. Whether or not a stress state has been 'visited' before is also vitally important in determining and understanding damage envelopes. Finally, we show that damage evolution can be anisotropic and must be considered as a three-dimensional problem. It is unclear how damage envelopes

  6. Penicillin-binding site on the Escherichia coli cell envelope

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, L.; Lee, Y.; Schwarz, U.; Lorian, V.

    1986-08-01

    The binding of /sup 35/S-labeled penicillin to distinct penicillin-binding proteins (PBPs) of the cell envelope obtained from the sonication of Escherichia coli was studied at different pHs ranging from 4 to 11. Experiments distinguishing the effect of pH on penicillin binding by PBP 5/6 from its effect on beta-lactamase activity indicated that although substantial binding occurred at the lowest pH, the amount of binding increased with pH, reaching a maximum at pH 10. Based on earlier studies, it is proposed that the binding at high pH involves the formation of a covalent bond between the C-7 of penicillin and free epsilon amino groups of the PBPs. At pHs ranging from 4 to 8, position 1 of penicillin, occupied by sulfur, is considered to be the site that establishes a covalent bond with the sulfhydryl groups of PBP 5. The use of specific blockers of free epsilon amino groups or sulfhydryl groups indicated that wherever the presence of each had little or no effect on the binding of penicillin by PBP 5, the presence of both completely prevented binding. The specific blocker of the hydroxyl group of serine did not affect the binding of penicillin.

  7. Energy transport by convection in the common envelope evolution

    Science.gov (United States)

    Sabach, Efrat; Hillel, Shlomi; Schreier, Ron; Soker, Noam

    2017-12-01

    We argue that outward transport of energy by convection and photon diffusion in a common envelope evolution (CEE) of giant stars substantially reduces the fraction of the recombination energy of hydrogen and helium that is available for envelope removal. We base our estimate on the properties of an unperturbed asymptotic giant branch spherical model, and on some simple arguments. Since during the CEE the envelope expands and energy removal by photon diffusion becomes more efficient, our arguments underestimate the escape of recombination energy. We hence strengthen earlier claims that recombination energy does not contribute much to common envelope removal. A large fraction of the energy that jets deposit to the envelope, on the other hand, might be in the form of kinetic energy of the expanding and buoyantly rising hot bubbles. These rapidly rising bubbles remove mass from the envelope. We demonstrate this process by conducting a three-dimensional hydrodynamical simulation where we deposit hot gas in the location of a secondary star that orbits inside the envelope of a giant star. Despite the fact that we do not include the large amount of gravitational energy that is released by the in-spiralling secondary star, the hot bubbles alone remove mass at a rate of about 0.1 M⊙ yr- 1, which is much above the regular mass-loss rate.

  8. Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor, E-mail: leonorhh@biomedicas.unam.mx

    2017-03-01

    Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4{sup +} T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

  9. ANALYSES AND INFLUENCES OF GLAZED BUILDING ENVELOPES

    Directory of Open Access Journals (Sweden)

    Sabina Jordan

    2011-01-01

    Full Text Available The article presents the results of an analytical study of the functioning of glazing at two different yet interacting levels: at the level of the building as a whole, and at that of glazing as a building element. At the building level, analyses were performed on a sample of high-rise business buildings in Slovenia, where the glazing"s share of the building envelope was calculated, and estimates of the proportion of shade provided by external blinds were made. It is shown that, especially in the case of modern buildings with large proportions of glazing and buildings with no shading devices, careful glazing design is needed, together with a sound knowledge of energy performance. In the second part of the article, the energy balance values relating to selected types of glazing are presented, including solar control glazing. The paper demonstrates the need for a holistic energy approach to glazing problems, as well as how different types of glazing can be methodically compared, thus improving the design of sustainability-orientated buildings.

  10. A Functional Henipavirus Envelope Glycoprotein Pseudotyped Lentivirus Assay System

    Directory of Open Access Journals (Sweden)

    Broder Christopher C

    2010-11-01

    Full Text Available Abstract Background Hendra virus (HeV and Nipah virus (NiV are newly emerged zoonotic paramyxoviruses discovered during outbreaks in Queensland, Australia in 1994 and peninsular Malaysia in 1998/9 respectively and classified within the new Henipavirus genus. Both viruses can infect a broad range of mammalian species causing severe and often-lethal disease in humans and animals, and repeated outbreaks continue to occur. Extensive laboratory studies on the host cell infection stage of HeV and NiV and the roles of their envelope glycoproteins have been hampered by their highly pathogenic nature and restriction to biosafety level-4 (BSL-4 containment. To circumvent this problem, we have developed a henipavirus envelope glycoprotein pseudotyped lentivirus assay system using either a luciferase gene or green fluorescent protein (GFP gene encoding human immunodeficiency virus type-1 (HIV-1 genome in conjunction with the HeV and NiV fusion (F and attachment (G glycoproteins. Results Functional retrovirus particles pseudotyped with henipavirus F and G glycoproteins displayed proper target cell tropism and entry and infection was dependent on the presence of the HeV and NiV receptors ephrinB2 or B3 on target cells. The functional specificity of the assay was confirmed by the lack of reporter-gene signals when particles bearing either only the F or only G glycoprotein were prepared and assayed. Virus entry could be specifically blocked when infection was carried out in the presence of a fusion inhibiting C-terminal heptad (HR-2 peptide, a well-characterized, cross-reactive, neutralizing human mAb specific for the henipavirus G glycoprotein, and soluble ephrinB2 and B3 receptors. In addition, the utility of the assay was also demonstrated by an examination of the influence of the cytoplasmic tail of F in its fusion activity and incorporation into pseudotyped virus particles by generating and testing a panel of truncation mutants of NiV and HeV F

  11. The nuclear envelope environment and its cancer connections

    Science.gov (United States)

    Chow, Kin-Hoe; Factor, Rachel E.; Ullman, Katharine S.

    2014-01-01

    Because of the association between aberrant nuclear structure and tumour grade, nuclear morphology is an indispensible criterion in the current pathological assessment of cancer. Components of the nuclear envelope environment have central roles in many aspects of cell function that affect tumour development and progression. As the roles of the nuclear envelope components, including nuclear pore complexes and nuclear lamina, are being deciphered in molecular detail there are opportunities to harness this knowledge for cancer therapeutics and biomarker development. In this Review, we summarize the progress that has been made in our understanding of the nuclear envelope and the implications of changes in this environment for cancer biology. PMID:22337151

  12. DATA ENVELOPMENT ANALYSIS OF BANKING SECTOR IN BANGLADESH

    Directory of Open Access Journals (Sweden)

    Md. Rashedul Hoque

    2012-05-01

    Full Text Available Banking sector of Bangladesh is flourishing and contributing to its economy. In this aspect measuring efficiency is important. Data Envelopment Analysis technique is used for this purpose. The data are collected from the annual reports of twenty four different banks in Bangladesh. Data Envelopment Analysis is mainly of two types - constant returns to scale and variable returns to scale. Since this study attempts to maximize output, so the output oriented Data Envelopment Analysis is used. The most efficient bank is one that obtains the highest efficiency score.

  13. Pre-paid envelopes commemorating the 2013 Open Days

    CERN Multimedia

    2013-01-01

    The post office on CERN's Prévessin site is still selling pre-paid envelopes commemorating the 2013 Open Days. Hurry while stocks last!   The special envelopes, which are valid in France for non-priority letters weighing up to 20 grams, are ideal for your Christmas and New Year correspondence. A set of ten envelopes, each featuring a different image, costs € 8.70 or 10 CHF. The post office is located in Building 866 on the Prévessin site and is open Mondays to Thursdays from 9.30 a.m. to 12.30 p.m.

  14. Envelope parameters, their effect on high-rise buildings

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, M.J.

    1982-04-01

    Makeup of the exterior envelope of a high-rise building - walls, insulation, glass, mass - greatly affects both peak and total structure energy usages. The influence of a well-designed building envelope on energy conservation is considered and the effects of envelope parameters on high-rise building energy use and costs are addressed. A general guideline for the building design team is given. By knowing the ramifications of certain design decisions, a design team can effectively plan a useful and energy-efficient building.

  15. Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Silvia A.; Paladino, Monica G. [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina); Affranchino, Jose L., E-mail: jose.affranchino@comunidad.ub.edu.ar [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina)

    2012-06-20

    The feline immunodeficiency virus (FIV) envelope glycoprotein (Env) possesses a short cytoplasmic domain of 53 amino acids containing four highly conserved cysteines at Env positions 804, 811, 815 and 848. Since palmitoylation of transmembrane proteins occurs at or near the membrane anchor, we investigated whether cysteines 804, 811 and 815 are acylated and analyzed the relevance of these residues for Env functions. Replacement of cysteines 804, 811 and 815 individually or in combination by serine residues resulted in Env glycoproteins that were efficiently expressed and processed. However, mutations C804S and C811S reduced Env fusogenicity by 93% and 84%, respectively, compared with wild-type Env. By contrast, mutant C815S exhibited a fusogenic capacity representing 50% of the wild-type value. Remarkably, the double mutation C804S/C811S abrogated both Env fusion activity and Env incorporation into virions. Finally, by means of Click chemistry assays we demonstrated that the four FIV Env cytoplasmic cysteines are palmitoylated.

  16. Fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the Xenopus laevis ZP3.

    Science.gov (United States)

    Miwa, Naofumi; Ogawa, Motoyuki; Hanaue, Mayu; Takamatsu, Ken

    2015-08-05

    Fertilization begins with species-restricted interaction of sperm and the egg-coating envelope, which includes a three-dimensional meshwork of filaments composed of glycoproteins (called ZP proteins). Growing evidence has unveiled the molecular nature of ZP proteins; however, the structural property conferring fertilization competence to the egg-coating envelope remains unknown. Here, we show the molecular mechanism that mediates direct interaction between dicalcin, a novel fertilization-suppressive ZP protein-associated protein, and gp41, a Xenopus laevis ortholog of mammalian ZP3, and subsequently demonstrate the structural basis of the envelope for fertilization competence. The interactive regions between dicalcin and gp41 comprised five and nine amino acid residues within dicalcin and twenty-three within gp41 [corrected]. Synthetic peptides corresponding to these regions dramatically affected fertilization: treatment with dicalcin- or gp41-derived peptides decreased or increased fertilization rates, respectively. Prior application of these peptides caused distinct alterations in the in vivo lectin-staining pattern of the envelope as well. Transmission electron microscopy analysis revealed that the dicalcin-derived peptide induced the formation of a well-organized meshwork, whereas the gp41-derived peptide caused the formation of a significantly disorganized meshwork. These findings indicated that the fertilization competence of the egg-coating envelope is crucially regulated by the direct interaction between dicalcin and gp41.

  17. Phospholipase A2 isolated from the venom of Crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.

    Directory of Open Access Journals (Sweden)

    Vanessa Danielle Muller

    Full Text Available The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

  18. Phospholipase A2 isolated from the venom of Crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.

    Science.gov (United States)

    Muller, Vanessa Danielle; Soares, Ricardo Oliveira; dos Santos, Nilton Nascimento; Trabuco, Amanda Cristina; Cintra, Adelia Cristina; Figueiredo, Luiz Tadeu; Caliri, Antonio; Sampaio, Suely Vilela; Aquino, Victor Hugo

    2014-01-01

    The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

  19. A tamB homolog is involved in maintenance of cell envelope integrity and stress resistance of Deinococcus radiodurans

    Science.gov (United States)

    Yu, Jiangliu; Li, Tao; Dai, Shang; Weng, Yulan; Li, Jiulong; Li, Qinghao; Xu, Hong; Hua, Yuejin; Tian, Bing

    2017-01-01

    The translocation and assembly module (TAM) in bacteria consists of TamA and TamB that form a complex to control the transport and secretion of outer membrane proteins. Herein, we demonstrated that the DR_1462-DR_1461-DR_1460 gene loci on chromosome 1 of Deinococcus radiodurans, which lacks tamA homologs, is a tamB homolog (DR_146T) with two tamB motifs and a DUF490 motif. Mutation of DR_146T resulted in cell envelope peeling and a decrease in resistance to shear stress and osmotic pressure, as well as an increase in oxidative stress resistance, consistent with the phenotype of a surface layer (S-layer) protein SlpA (DR_2577) mutant, demonstrating the involvement of DR_146T in maintenance of cell envelope integrity. The 123 kDa SlpA was absent and only its fragments were present in the cell envelope of DR_146T mutant, suggesting that DR_146T might be involved in maintenance of the S-layer. A mutant lacking the DUF490 motif displayed only a slight alteration in phenotype compared with the wild type, suggesting DUF490 is less important than tamB motif for the function of DR_146T. These findings enhance our understanding of the properties of the multilayered envelope in extremophilic D. radiodurans, as well as the diversity and functions of TAMs in bacteria. PMID:28383523

  20. A tamB homolog is involved in maintenance of cell envelope integrity and stress resistance of Deinococcus radiodurans.

    Science.gov (United States)

    Yu, Jiangliu; Li, Tao; Dai, Shang; Weng, Yulan; Li, Jiulong; Li, Qinghao; Xu, Hong; Hua, Yuejin; Tian, Bing

    2017-04-06

    The translocation and assembly module (TAM) in bacteria consists of TamA and TamB that form a complex to control the transport and secretion of outer membrane proteins. Herein, we demonstrated that the DR_1462-DR_1461-DR_1460 gene loci on chromosome 1 of Deinococcus radiodurans, which lacks tamA homologs, is a tamB homolog (DR_146T) with two tamB motifs and a DUF490 motif. Mutation of DR_146T resulted in cell envelope peeling and a decrease in resistance to shear stress and osmotic pressure, as well as an increase in oxidative stress resistance, consistent with the phenotype of a surface layer (S-layer) protein SlpA (DR_2577) mutant, demonstrating the involvement of DR_146T in maintenance of cell envelope integrity. The 123 kDa SlpA was absent and only its fragments were present in the cell envelope of DR_146T mutant, suggesting that DR_146T might be involved in maintenance of the S-layer. A mutant lacking the DUF490 motif displayed only a slight alteration in phenotype compared with the wild type, suggesting DUF490 is less important than tamB motif for the function of DR_146T. These findings enhance our understanding of the properties of the multilayered envelope in extremophilic D. radiodurans, as well as the diversity and functions of TAMs in bacteria.

  1. Nuclear Envelope Retention of LINC Complexes Is Promoted by SUN-1 Oligomerization in the Caenorhabditis elegans Germ Line.

    Science.gov (United States)

    Daryabeigi, Anahita; Woglar, Alexander; Baudrimont, Antoine; Silva, Nicola; Paouneskou, Dimitra; Vesely, Cornelia; Rauter, Manuel; Penkner, Alexandra; Jantsch, Michael; Jantsch, Verena

    2016-06-01

    SUN (Sad1 and UNC-84) and KASH (Klarsicht, ANC-1, and Syne homology) proteins are constituents of the inner and outer nuclear membranes. They interact in the perinuclear space via C-terminal SUN-KASH domains to form the linker of nucleoskeleton and cytoskeleton (LINC) complex thereby bridging the nuclear envelope. LINC complexes mediate numerous biological processes by connecting chromatin with the cytoplasmic force-generating machinery. Here we show that the coiled-coil domains of SUN-1 are required for oligomerization and retention of the protein in the nuclear envelope, especially at later stages of female gametogenesis. Consistently, deletion of the coiled-coil domain makes SUN-1 sensitive to unilateral force exposure across the nuclear membrane. Premature loss of SUN-1 from the nuclear envelope leads to embryonic death due to loss of centrosome-nuclear envelope attachment. However, in contrast to previous notions we can show that the coiled-coil domain is dispensable for functional LINC complex formation, exemplified by successful chromosome sorting and synapsis in meiotic prophase I in its absence. Copyright © 2016 by the Genetics Society of America.

  2. Interphase nuclei of many mammalian cell types contain deep, dynamic, tubular membrane-bound invaginations of the nuclear envelope.

    Science.gov (United States)

    Fricker, M; Hollinshead, M; White, N; Vaux, D

    1997-02-10

    The nuclear envelope consists of a double-membraned extension of the rough endoplasmic reticulum. In this report we describe long, dynamic tubular channels, derived from the nuclear envelope, that extend deep into the nucleoplasm. These channels show cell-type specific morphologies ranging from single short stubs to multiple, complex, branched structures. Some channels transect the nucleus entirely, opening at two separate points on the nuclear surface, while others terminate at or close to nucleoli. These channels are distinct from other topological features of the nuclear envelope, such as lobes or folds. The channel wall consists of two membranes continuous with the nuclear envelope, studded with features indistinguishable from nuclear pore complexes, and decorated on the nucleoplasmic surface with lamins. The enclosed core is continuous with the cytoplasm, and the lumenal space between the membranes contains soluble ER-resident proteins (protein disulphide isomerase and glucose-6-phosphatase). Nuclear channels are also found in live cells labeled with the lipophilic dye DiOC6. Time-lapse imaging of DiOC6-labeled cells shows that the channels undergo changes in morphology and spatial distribution within the interphase nucleus on a timescale of minutes. The presence of a cytoplasmic core and nuclear pore complexes in the channel walls suggests a possible role for these structures in nucleo-cytoplasmic transport. The clear association of a subset of these structures with nucleoli would also be consistent with such a transport role.

  3. Intelligent building envelopes. Architectural concept and applications for daylighting quality

    Energy Technology Data Exchange (ETDEWEB)

    Wyckmans, Annemie

    2005-11-15

    How does an intelligent building envelope manage the variable and sometimes conflictive occupant requirements that arise in a day lit indoor environment. This is the research question that provides the basis for this Ph.D. work. As it touches upon several fields of application, the research question is untangled into four steps, each of which corresponds to a chapter of the thesis. 1) What characterises intelligent behaviour for a building envelope. 2) What characterises indoor day lighting quality. 3) Which functions can an intelligent building envelope be expected to perform in the context of day lighting quality. 4) How are the materials, components and composition of an intelligent building envelope designed to influence this performance. The emphasis is on design, environmental aspects, energy conservation, functional analysis and physical applications.

  4. Full waveform inversion using envelope-based global correlation norm

    Science.gov (United States)

    Oh, Ju-Won; Alkhalifah, Tariq

    2018-01-01

    To increase the feasibility of full waveform inversion on real data, we suggest a new objective function, which is defined as the global correlation of the envelopes of modeled and observed data. The envelope-based global correlation norm has the advantage of the envelope inversion that generates artificial low-frequency information, which provides the possibility to recover long-wavelength structure in an early stage. In addition, the envelope-based global correlation norm maintains the advantage of the global correlation norm, which reduces the sensitivity of the misfit to amplitude errors so that the performance of inversion on real data can be enhanced when the exact source wavelet is not available and more complex physics are ignored.

  5. Transport of Ions Across the Inner Envelope Membrane of Chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, R. E.

    2004-06-02

    The technical report outlines the results of nine years of research on how ions cross the inner envelope membrane of chloroplasts. The ions include protons, nitrite, calcium and ferrous iron. Bicarbonate transport was also studied.

  6. Envelope Protection for In-Flight Ice Contamination

    Science.gov (United States)

    Gingras, David R.; Barnhart, Billy P.; Ranaudo, Richard J.; Ratvasky, Thomas P.; Morelli, Eugene A.

    2010-01-01

    Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.

  7. Low Permeation Envelope Material Development for Titan Aerobot Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerobot vehicles for missions on Titan require envelope materials that are strong, light and durable. Unlike terrestrial balloon materials, these must be able to...

  8. Low Permeation Envelope Material Development for Titan Aerobot Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerobot vehicles for missions on Titan require envelope materials that are strong, light and durable. In particular they must be able to withstand flexing at liquid...

  9. Application of data envelopment analysis models in supply chain management

    DEFF Research Database (Denmark)

    Soheilirad, Somayeh; Govindan, Kannan; Mardani, Abbas

    2017-01-01

    Supply chain management aims to designing, managing and coordinating material/product, information and financial flows to fulfill the customer requirements at low costs and thereby increasing supply chain profitability. In the last decades, data envelopment analysis has become the main topic...... of interest as a mathematical tool to evaluate supply chain management. While, various data envelopment analysis models have been suggested to measure and evaluate the supply chain management, there is a lack of research regarding to systematic literature review and classification of study in this field...... have been attained to reach a comprehensive review of data envelopment analysis models in evaluation supply chain management. Consequently, the selected published articles have been categorized by author name, the year of publication, technique, application area, country, scope, data envelopment...

  10. 300 Area Liquid Effluent Facilities (LEF) Authorization Envelope

    Energy Technology Data Exchange (ETDEWEB)

    WRIGHT, E.J.; STORDEUR, R.T.

    2000-04-07

    The purpose of this document is to establish the facility Authorization Envelope (AE) for the 300 Liquid Effluent Facilities (LEP )Project and identify the requirements related to the maintenance of the AE as Specified in HNF-PRO-2701, Authorization Envelope and Authorization Agreement. The 300 LEF Project consists of two separate facilities operating under one management organization. They are the 310 Facility and the 340 Facility. The AE documents the limits of operations for all 300 LEF Project activities.

  11. A New Envelope with Highly Energy-Efficient Insulation

    OpenAIRE

    Alonso Pastor, Luis Alberto; Lauret Aguirregabiria, Benito; Alonso Amo, Fernando

    2010-01-01

    This article examines, from the insulation viewpoint, a new lightweight, slim, high energy efficient, lighttransmitting envelope system, providing for seamless, free-form designs for use in architectural projects. The research was based on envelope components already existing on the market, especially components implemented with granular silica gel insulation, as this is the most effective translucent thermal insulation there is today. The tests run on these materials revealed tha...

  12. Episodic mass ejections from common-envelope objects

    Science.gov (United States)

    Clayton, Matthew; Podsiadlowski, Philipp; Ivanova, Natasha; Justham, Stephen

    2017-09-01

    After the initial fast spiral-in phase experienced by a common-envelope binary, the system may enter a slow, self-regulated phase, possibly lasting hundreds of years, in which all the energy released by orbital decay can be efficiently transported to the surface, where it is radiated away. If the remaining envelope is to be removed during this phase, this removal must occur through some as-yet-undetermined mechanism. We carried out 1D hydrodynamic simulations of a low-mass red giant undergoing a synthetic common-envelope event in such a slow spiral-in phase, using the stellar evolutionary code mesa. We simulated the heating of the envelope due to frictional dissipation from a binary companion's orbit in multiple configurations and investigated the response of the giant's envelope. We find that our model envelopes become dynamically unstable and develop large-amplitude pulsations, with periods in the range 3-20 yr and very short growth time-scales of similar order. The shocks and associated rebounds that emerge as these pulsations grow are in some cases strong enough to dynamically eject shells of matter of up to 0.1 M⊙, ˜10 per cent of the mass of the envelope, from the stellar surface at above escape velocity. These ejections are seen to repeat within a few decades, leading to a time-averaged mass-loss rate of the order of 10-3 M⊙ yr-1, which is sufficiently high to represent a candidate mechanism for removing the entire envelope over the duration of the slow spiral-in phase.

  13. Preserving Envelope Efficiency in Performance Based Code Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Brian A. [Thornton Energy Consulting (United States); Sullivan, Greg P. [Efficiency Solutions (United States); Rosenberg, Michael I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baechler, Michael C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-20

    The City of Seattle 2012 Energy Code (Seattle 2014), one of the most progressive in the country, is under revision for its 2015 edition. Additionally, city personnel participate in the development of the next generation of the Washington State Energy Code and the International Energy Code. Seattle has pledged carbon neutrality by 2050 including buildings, transportation and other sectors. The United States Department of Energy (DOE), through Pacific Northwest National Laboratory (PNNL) provided technical assistance to Seattle in order to understand the implications of one potential direction for its code development, limiting trade-offs of long-lived building envelope components less stringent than the prescriptive code envelope requirements by using better-than-code but shorter-lived lighting and heating, ventilation, and air-conditioning (HVAC) components through the total building performance modeled energy compliance path. Weaker building envelopes can permanently limit building energy performance even as lighting and HVAC components are upgraded over time, because retrofitting the envelope is less likely and more expensive. Weaker building envelopes may also increase the required size, cost and complexity of HVAC systems and may adversely affect occupant comfort. This report presents the results of this technical assistance. The use of modeled energy code compliance to trade-off envelope components with shorter-lived building components is not unique to Seattle and the lessons and possible solutions described in this report have implications for other jurisdictions and energy codes.

  14. The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution

    Science.gov (United States)

    Fischer, William J.; Megeath, S. Thomas; Furlan, Elise; Ali, Babar; Stutz, Amelia M.; Tobin, John J.; Osorio, Mayra; Stanke, Thomas; Manoj, P.; Poteet, Charles A.; Booker, Joseph J.; Hartmann, Lee; Wilson, Thomas L.; Myers, Philip C.; Watson, Dan M.

    2017-05-01

    The Herschel Orion Protostar Survey obtained well-sampled 1.2-870 μm spectral energy distributions (SEDs) of over 300 protostars in the Orion molecular clouds, home to most of the young stellar objects (YSOs) in the nearest 500 pc. We plot the bolometric luminosities and temperatures for 330 Orion YSOs, 315 of which have bolometric temperatures characteristic of protostars. The histogram of the bolometric temperature is roughly flat; 29% of the protostars are in Class 0. The median luminosity decreases by a factor of four with increasing bolometric temperature; consequently, the Class 0 protostars are systematically brighter than the Class I protostars, with a median luminosity of 2.3 L⊙ as opposed to 0.87 L⊙. At a given bolometric temperature, the scatter in luminosities is three orders of magnitude. Using fits to the SEDs, we analyze how the luminosities corrected for inclination and foreground reddening relate to the mass in the inner 2500 au of the best-fit model envelopes. The histogram of the envelope mass is roughly flat, while the median-corrected luminosity peaks at 15 L⊙ for young envelopes and falls to 1.7 L⊙ for late-stage protostars with remnant envelopes. The spread in luminosity at each envelope mass is three orders of magnitude. Envelope masses that decline exponentially with time explain the flat mass histogram and the decrease in luminosity, while the formation of a range of stellar masses explains the dispersion in luminosity.

  15. An E2?F12 complex is required for intracellular enveloped virus morphogenesis during vaccinia infection

    OpenAIRE

    Dodding, Mark P; Newsome, Timothy P; Collinson, Lucy M; Edwards, Ceri; Way, Michael

    2009-01-01

    The vaccinia virus protein, F12, has been suggested to play an important role in microtubule-based transport of intracellular enveloped virus (IEV). We found that GFP-F12 is recruited to IEV moving on microtubules but is released from virus particles when they switch to actin-based motility. In the absence of F12, although the majority of IEV remain close to their peri-nuclear site of assembly, a small number of IEV still move with linear trajectories at speeds of 0.85 ?m s?1, consistent with...

  16. Multicriteria approach to data envelopment analysis

    Directory of Open Access Journals (Sweden)

    Hélcio Vieira Junior

    2008-08-01

    Full Text Available With the aim of making Data Envelopment Analysis (DEA more acceptable to the managers' community, the Weights Restrictions approaches were born. They allow DEA to not dispose of any data and permit the Decision Maker (DM to have some management over the method. The purpose of this paper is to suggest a Weights Restrictions DEA model that incorporates the DM preference. In order to perform that, we employed the MACBETH methodology as a tool to find out the bounds of the weights to be used in a Weights Restrictions approach named Virtual Weights Restrictions. Our proposal achieved an outcome that has an expressive correlation with three widely used decision-aids methodologies: the ELECTRE III, the SMART and the PROMETHEE I and II. In addition, our approach was able to join the most significant outcomes of all the above three Multicriteria decision-aids methodologies in one unique outcome.Com o objetivo de fazer a Análise Envoltória de Dados (DEA mais aceitável pela comunidade gerencial, as abordagens de Restrição aos Pesos foram criadas. Estas abordagens fazem com que a DEA não descarte nenhum dado e permitem que o Decisor (DM tenha alguma gerência sobre o método. O objetivo deste artigo é sugerir um modelo de restrição aos pesos que incorpore as preferências do DM. Para realizar isto, nós empregamos a metodologia MACBETH como ferramenta para descobrir os limites dos pesos a serem utilizados na abordagem de restrição aos pesos chamada "Restrição aos Pesos Virtuais". Nossa proposta alcançou um resultado que apresenta uma correlação expressiva com três metodologias de apoio à decisão amplamente utilizadas: o ELECTRE III, o SMART e o PROMETHEE I e II. Adicionalmente, nossa abordagem foi capaz de reunir os resultados mais significativos de todas estas três metodologias de apoio à decisão em um único resultado.

  17. The plant nuclear envelope as a multifunctional platform LINCed by SUN and KASH.

    Science.gov (United States)

    Zhou, Xiao; Graumann, Katja; Meier, Iris

    2015-03-01

    The nuclear envelope (NE) is a double membrane system enclosing the genome of eukaryotes. Besides nuclear pore proteins, which form channels at the NE, nuclear membranes are populated by a collection of NE proteins that perform various cellular functions. However, in contrast to well-conserved nuclear pore proteins, known NE proteins share little homology between opisthokonts and plants. Recent studies on NE protein complexes formed by Sad1/UNC-84 (SUN) and Klarsicht/ANC-1/Syne-1 Homology (KASH) proteins have advanced our understanding of plant NE proteins and revealed their function in anchoring other proteins at the NE, nuclear shape determination, nuclear positioning, anti-pathogen defence, root development, and meiotic chromosome organization. In this review, we discuss the current understanding of plant SUN, KASH, and other related NE proteins, and compare their function with the opisthokont counterparts. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Untethering the Nuclear Envelope and Cytoskeleton: Biologically Distinct Dystonias Arising from a Common Cellular Dysfunction

    Directory of Open Access Journals (Sweden)

    Nadia A. Atai

    2012-01-01

    Full Text Available Most cases of early onset DYT1 dystonia in humans are caused by a GAG deletion in the TOR1A gene leading to loss of a glutamic acid (ΔE in the torsinA protein, which underlies a movement disorder associated with neuronal dysfunction without apparent neurodegeneration. Mutation/deletion of the gene (Dst encoding dystonin in mice results in a dystonic movement disorder termed dystonia musculorum, which resembles aspects of dystonia in humans. While torsinA and dystonin proteins do not share modular domain architecture, they participate in a similar function by modulating a structural link between the nuclear envelope and the cytoskeleton in neuronal cells. We suggest that through a shared interaction with the nuclear envelope protein nesprin-3α, torsinA and the neuronal dystonin-a2 isoform comprise a bridge complex between the outer nuclear membrane and the cytoskeleton, which is critical for some aspects of neuronal development and function. Elucidation of the overlapping roles of torsinA and dystonin-a2 in nuclear/endoplasmic reticulum dynamics should provide insights into the cellular mechanisms underlying the dystonic phenotype.

  19. RAB1A promotes Vaccinia virus replication by facilitating the production of intracellular enveloped virions

    Energy Technology Data Exchange (ETDEWEB)

    Pechenick Jowers, Tali; Featherstone, Rebecca J.; Reynolds, Danielle K.; Brown, Helen K. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom); James, John; Prescott, Alan [Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom); Haga, Ismar R. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom); Beard, Philippa M., E-mail: pip.beard@roslin.ed.ac.uk [The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, Scotland (United Kingdom)

    2015-01-15

    Vaccinia virus (VACV) is a large double-stranded DNA virus with a complex cytoplasmic replication cycle that exploits numerous cellular proteins. This work characterises the role of a proviral cellular protein, the small GTPase RAB1A, in VACV replication. Using siRNA, we identified RAB1A as required for the production of extracellular enveloped virions (EEVs), but not intracellular mature virions (IMVs). Immunofluorescence and electron microscopy further refined the role of RAB1A as facilitating the wrapping of IMVs to become intracellular enveloped virions (IEVs). This is consistent with the known function of RAB1A in maintenance of ER to Golgi transport. VACV can therefore be added to the growing list of viruses which require RAB1A for optimal replication, highlighting this protein as a broadly proviral host factor. - Highlights: • Characterisation of the role of the small GTPase RAB1A in VACV replication. • RAB1A is not required for production of the primary virion form (IMV). • RAB1A is required for production of processed virion forms (IEVs, CEVs and EEVs). • Consistent with known role of RAB1A in ER to Golgi transport.

  20. Different sympathetic pathways control the metabolism of distinct bone envelopes.

    Science.gov (United States)

    Bataille, Caroline; Mauprivez, Cédric; Haÿ, Eric; Baroukh, Brigitte; Brun, Adrian; Chaussain, Catherine; Marie, Pierre J; Saffar, Jean-Louis; Cherruau, Marc

    2012-05-01

    Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through

  1. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    Science.gov (United States)

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  2. Perinatal transmission of hepatitis C antigens: envelope 1, envelope 2 and non-structural 4.

    Science.gov (United States)

    Attallah, Abdelfattah M; Abdallah, Sanaa O; El-Far, Mohamed; Omran, Mohamed M; Tabll, Ashraf A; Ghaly, Mohamed F; Ezzat, Said M; Elhamshary, Manal O; El-Gohary, Zeinab M; Mohamedin, Attiya H; El-Morsi, Adel A; Askora, Ahmed A; Abdelrazek, Mohamed A; El-Kafrawy, Hala M; Keneber, Mohamed H; Khalil, Mohamed R; Aggag, Mostafa M; Elbendary, Mohamed S; El-Deeb, Menatallah M; Abuzaid, Mahmoud S; Mansour, Ahmed T; Attallah, Ahmed A

    2015-08-01

    Perinatal exposure to hepatitis C virus (HCV) antigens during pregnancy may affect the developing immune system in the fetus. We aimed to study the perinatal transmission of HCV structural and non-structural antigens. Sera from 402 pregnant mothers were tested for anti-HCV antibody and HCV RNA. HCV antigens were determined in sera from 101 HCV-infected mothers and their cord blood. In both serum and cord blood samples, HCV NS4 (non-structural 4) at 27 kDa, E1 (envelope 1) at 38 kDa and E2 (envelope 2) at 40 kDa were identified, purified and quantified using western blotting, electroelution and ELISA. Maternal sera and neonate cord blood samples had similar detection rates for NS4 (94.1%), E1 (90.1%) and E2 (90.1%). The mean maternal serum levels (optical density, OD) of HCV NS4 (0.87 ± 0.01), E1 (0.86 ± 0.01) and E2 (0.85 ± 0.01) did not differ significantly (p > 0.05) from those of neonatal cord blood (0.83 ± 0.01, 0.87 ± 0.01 and 0.85 ± 0.01, respectively). Also, strong correlations (p 0.05) from those in caesarean section. These findings indicate that vertical transmission of HCV NS4, E1 and E2 antigens was very high. Thus, exposure to these antigens may influence the developing immune responses to natural infection or future vaccination.

  3. Integrated energy design of the building envelope

    Energy Technology Data Exchange (ETDEWEB)

    Vraa Nielsen, M.

    2012-07-01

    This thesis describes the outcome of the PhD project Integrated energy design of the building envelope carried out through a combination of scientific dissemination reported through peer-reviewed journals and a wide range of affiliated projects involved in at an architectural firm. The research project analysed how the implementation of technical knowledge early in the building design process can quantify the effect of a building's facades on its energy efficiency and indoor climate and thereby facilitate a more qualified design development. The project was structured in the following way: 1) the importance of integrating knowledge in the early stages of design, and how it can be done; 2) understanding the facade's typology; and 3) the complex notion of comfort. The project touched not only on the technical capabilities and requirements governing facade design, but also the process by which it takes place. This was done by applying the methodology of Integrated Energy Design (IED) and analysing its applicability in the design of facades. A major part of the project was an actual engagement in the architectural process to test out incorporating a consciousness about energy and comfort as part of a more holistic performance evaluation. The research project illustrates the great potential in taking passive properties into account through a geometrical optimisation inherent in the development of the architectural concept. It demonstrates that integration of technical knowledge at the early stages of design not only can qualify the geometrical processing, but also facilitate the design development of the facade. Thereby a more holistic performance optimisation can be obtained through parameters such as overall facade geometry and orientation, functional organisation, room height and depth, facade layout, window geometry and transparency, design of the window aperture, etc. Through the wide range of affiliated project involved in at the architectural firm over

  4. Building envelope innovation: smart facades for non residential buildings

    Directory of Open Access Journals (Sweden)

    Marco Sala

    2011-11-01

    Full Text Available The research analyzes the evolution of smart façade systems in the area of design and industrial production, in order to investigate the technological, functional and qualitative standards of dynamic façade and evaluate the energy performance of the building envelope as a dynamic system that interacts between indoor and outdoor environment. The study focused on dynamic envelopes for office building analyzing the evolution of façade systems in terms of: building construction, innovative systems, smart materials, dynamic system. Aiming to improve building energy performances. The research, developed during the PhD thesis “Smart Envelope - dynamic and innovative technologies for energy saving” and the research “Abitare Mediterraneo”, aims to identify and define the energy performances of smart envelopes trough the analysis of the state of art, related to dynamic building envelope of double skin façade, and the development of a new dynamic façade system.

  5. HST Images of Protostellar Disks and Envelopes in Orion

    Science.gov (United States)

    Booker, Joseph; Fischer, Will; Megeath, Tom; Tobin, John; Kounkel, Marina; Poteet, Charles; Ali, Babar; Furlan, Elise; Stanke, Thomas; Stutz, Amelia

    2013-07-01

    We present near-infrared HST NICMOS+WFC3 images of disk shadows, envelopes, and envelope cavities of 244 Orion protostars at better than 100 AU spatial resolution. Orion is home to half the young stellar objects in the nearest 500 pc and is a largely unexplored ground for scattered-light studies of protostellar envelopes and disks. This region is the focus of HOPS, the Herschel Orion Protostar Survey, a multi-observatory study of protostars using Herschel, Spitzer, Hubble, and APEX. Scattered light images allow us to break degeneracies in fitting the 1-870 micron spectral energy distributions (see posters by E. Furlan and W. Fischer), in particular by constraining the inclination of the source and the opening angle of the envelope cavity. We present a grid of ~2900 models of the scattered light images to show how the nebulosity depends on cavity shape and inclination. For edge-on protostars, the comparison of the HST images to models allows us to determine the properties of protostellar disks by their shape in absorption against the scattered light and by the shadows they cast in the envelope. We present an initial example of HOPS 136 (Fischer et al. in prep.), where we have used the NICMOS data to provide strong constraints on the disk radius, mass, and structure, and we present a sample of 15 edge-on sources that are the subject of a similar analysis.

  6. Solar envelope concepts: moderate density building applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, R.L.; Berry, R.D.

    1980-04-01

    Solar energy utilization in urban areas requires public guarantees that all property owners have direct access to the sun. The study examines the implications of this premise in relation to the need for cities to also encourage or accommodate rebuilding and future development. The public policy mechanism for guaranteeing solar access is conceptualized as a solar zoning envelope that allows the largest possible building bulk on a land parcel without shadowing neighboring properties during specified times. Step-by-step methods for generating solar envelopes are described with extensive drawings, showing a variety of urban platting and lot configurations. Development and design possibilities are examined on a selected set of Los Angeles sites with typically diverse urban characteristics. Envelope attributes suitable for encouraging moderate-density commercial and residential building are examined in the context of two hypothetical but realistic development programs: one for speculative office buildings and one for condominium housing. Numerous illustrations of envelope forms and prototypical building designs are provided. The results of development simulation studies on all test sites are tabulated to show building bulk, density, land-coverage and open space characteristics obtainable under the hypothesized envelopes.

  7. African swine fever virus is enveloped by a two-membraned collapsed cisterna derived from the endoplasmic reticulum.

    Science.gov (United States)

    Andrés, G; García-Escudero, R; Simón-Mateo, C; Viñuela, E

    1998-11-01

    During the cytoplasmic maturation of African swine fever virus (ASFV) within the viral factories, the DNA-containing core becomes wrapped by two shells, an inner lipid envelope and an outer icosahedral capsid. We have previously shown that the inner envelope is derived from precursor membrane-like structures on which the capsid layer is progressively assembled. In the present work, we analyzed the origin of these viral membranes and the mechanism of envelopment of ASFV. Electron microscopy studies on permeabilized infected cells revealed the presence of two tightly apposed membranes within the precursor membranous structures as well as polyhedral assembling particles. Both membranes could be detached after digestion of intracellular virions with proteinase K. Importantly, membrane loop structures were observed at the ends of open intermediates, which suggests that the inner envelope is derived from a membrane cisterna. Ultraestructural and immunocytochemical analyses showed a close association and even direct continuities between the endoplasmic reticulum (ER) and assembling virus particles at the bordering areas of the viral factories. Such interactions become evident with an ASFV recombinant that inducibly expresses the major capsid protein p72. In the absence of the inducer, viral morphogenesis was arrested at a stage at which partially and fully collapsed ER cisternae enwrapped the core material. Together, these results indicate that ASFV, like the poxviruses, becomes engulfed by a two-membraned collapsed cisterna derived from the ER.

  8. Dansyl chloride labeling of Pseudomonas aeruginosa treated with pyocin R1: change in permeability of the cell envelope.

    OpenAIRE

    Uratani, Y

    1982-01-01

    Pyocin R1, a bacteriocin of Pseudomonas aeruginosa, caused an increase in binding of fluorescent label, 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride), to sensitive cells. In pyocin R1-treated cells, cytoplasmic soluble proteins and crude ribosomes as well as cell envelopes were labeled by dansyl chloride. The amount of bound dye was proportional to the multiplicity of pyocin R1 and reached a maximal level at high multiplicity. In addition, pyocin R1 rapidly caused an increa...

  9. Characterization and Enhanced Processing of Soluble, Oligomeric gp140 Envelope Glycoproteins Derived from Human Immunodeficiency Virus Type-1 Primary Isolates

    Science.gov (United States)

    2001-05-01

    97). Herzberg and colleague have been able to induce long-lasting central neuropathology in the rat by directly applying gp120 to the sciatic...by lentil lectin chromatography as described above. The Envs were quantitated and sent to Buford Biomedical, Inc., Frederick , MD for encapsulation...Virol. 141:2139-2151. 131. Herzberg , U., and J. Sagen 2001. Peripheral nerve exposure to HIV viral envelope protein gp120 induces neuropathic pain

  10. Venture from the Interior-Herpesvirus pUL31 Escorts Capsids from Nucleoplasmic Replication Compartments to Sites of Primary Envelopment at the Inner Nuclear Membrane.

    Science.gov (United States)

    Bailer, Susanne M.

    2017-11-25

    Herpesviral capsid assembly is initiated in the nucleoplasm of the infected cell. Size constraints require that newly formed viral nucleocapsids leave the nucleus by an evolutionarily conserved vescular transport mechanism called nuclear egress. Mature capsids released from the nucleoplasm are engaged in a membrane-mediated budding process, composed of primary envelopment at the inner nuclear membrane and de-envelopment at the outer nuclear membrane. Once in the cytoplasm, the capsids receive their secondary envelope for maturation into infectious virions. Two viral proteins conserved throughout the herpesvirus family, the integral membrane protein pUL34 and the phosphoprotein pUL31, form the nuclear egress complex required for capsid transport from the infected nucleus to the cytoplasm. Formation of the nuclear egress complex results in budding of membrane vesicles revealing its function as minimal virus-encoded membrane budding and scission machinery. The recent structural analysis unraveled details of the heterodimeric nuclear egress complex and the hexagonal coat it forms at the inside of budding vesicles to drive primary envelopment. With this review, I would like to present the capsid-escort-model where pUL31 associates with capsids in nucleoplasmic replication compartments for escort to sites of primary envelopment thereby coupling capsid maturation and nuclear egress.

  11. Planetary Gearbox Fault Diagnosis Using Envelope Manifold Demodulation

    Directory of Open Access Journals (Sweden)

    Weigang Wen

    2016-01-01

    Full Text Available The important issue in planetary gear fault diagnosis is to extract the dependable fault characteristics from the noisy vibration signal of planetary gearbox. To address this critical problem, an envelope manifold demodulation method is proposed for planetary gear fault detection in the paper. This method combines complex wavelet, manifold learning, and frequency spectrogram to implement planetary gear fault characteristic extraction. The vibration signal of planetary gear is demodulated by wavelet enveloping. The envelope energy is adopted as an indicator to select meshing frequency band. Manifold learning is utilized to reduce the effect of noise within meshing frequency band. The fault characteristic frequency of the planetary gear is shown by spectrogram. The planetary gearbox model and test rig are established and experiments with planet gear faults are conducted for verification. All results of experiment analysis demonstrate its effectiveness and reliability.

  12. Post-common envelope binaries from SDSS - XVI. Long orbital period systems and the energy budget of common envelope evolution

    Science.gov (United States)

    Rebassa-Mansergas, A.; Zorotovic, M.; Schreiber, M. R.; Gänsicke, B. T.; Southworth, J.; Nebot Gómez-Morán, A.; Tappert, C.; Koester, D.; Pyrzas, S.; Papadaki, C.; Schmidtobreick, L.; Schwope, A.; Toloza, O.

    2012-06-01

    Virtually all close compact binary stars are formed through common envelope (CE) evolution. It is generally accepted that during this crucial evolutionary phase a fraction of the orbital energy is used to expel the envelope. However, it is unclear whether additional sources of energy, such as the recombination energy of the envelope, play an important role. Here we report the discovery of the second and third longest orbital period post-common envelope binaries (PCEBs) containing white dwarf (WD) primaries, i.e. SDSS J121130.94-024954.4 (? d) and SDSS J222108.45+002927.7 (? d), reconstruct their evolutionary history and discuss the implications for the energy budget of CE evolution. We find that, despite their long orbital periods, the evolution of both systems can still be understood without incorporating recombination energy, although at least small contributions of this additional energy seem to be likely. If recombination energy significantly contributes to the ejection of the envelope, more PCEBs with relatively long orbital periods (? d) harbouring massive WDs (?) should exist.

  13. The tracking of speech envelope in the human cortex.

    Directory of Open Access Journals (Sweden)

    Jan Kubanek

    Full Text Available Humans are highly adept at processing speech. Recently, it has been shown that slow temporal information in speech (i.e., the envelope of speech is critical for speech comprehension. Furthermore, it has been found that evoked electric potentials in human cortex are correlated with the speech envelope. However, it has been unclear whether this essential linguistic feature is encoded differentially in specific regions, or whether it is represented throughout the auditory system. To answer this question, we recorded neural data with high temporal resolution directly from the cortex while human subjects listened to a spoken story. We found that the gamma activity in human auditory cortex robustly tracks the speech envelope. The effect is so marked that it is observed during a single presentation of the spoken story to each subject. The effect is stronger in regions situated relatively early in the auditory pathway (belt areas compared to other regions involved in speech processing, including the superior temporal gyrus (STG and the posterior inferior frontal gyrus (Broca's region. To further distinguish whether speech envelope is encoded in the auditory system as a phonological (speech-related, or instead as a more general acoustic feature, we also probed the auditory system with a melodic stimulus. We found that belt areas track melody envelope weakly, and as the only region considered. Together, our data provide the first direct electrophysiological evidence that the envelope of speech is robustly tracked in non-primary auditory cortex (belt areas in particular, and suggest that the considered higher-order regions (STG and Broca's region partake in a more abstract linguistic analysis.

  14. A Phase-Change Composite for Use in Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Ron S. [LMES/ORNL; Stovall, T. K. [LMES/ORNL; Weaver, K. E. [LMES/ORNL; Wilkes, K. E. [LMES/ORNL; Roy, S. [PhD Research Group, Inc.

    1992-06-15

    The objective of this project is to develop composite thermal insulations containing phase-change materials for use in the building envelope. The use of a phase-change insulation composite in the building envelope could result in a significant increase in energy efficiency. PhD Research provided candidate phase-change composites, and ORNL performed analytical and experimental evaluations of their thermal performance. The thermal resistance of the prototype panels was somewhat less than that of commercial products, although their thermal capacity was greater. Using these results, PhD Research has been working to modify the design and to produce practical building elements that incorporate phase-change material.

  15. A spectral algorithm for envelope reduction of sparse matrices

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, S.T.; Simon, H.D. [NASA Ames Research Center, Moffett Field, CA (United States). Cray Research Inc.; Pothen, A. [Univ. of Waterloo, Ontario (Canada). Computer Science Dept.

    1993-12-31

    A new algorithm for reducing the envelope of a sparse matrix is presented. This algorithm is based on the computation of eigenvectors of the Laplacian matrix associated with the graph of the sparse matrix. A reordering of the sparse matrix is determined based on the numerical values of the entries of an eigenvector of the Laplacian matrix. Numerical results show that the new reordering algorithm can in some cases reduce the envelope by more than a factor of two over the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK`s reverse Cuthill-McKee (RCM).

  16. Selective Gammatone Envelope Feature for Robust Sound Event Recognition

    Science.gov (United States)

    Leng, Yi Ren; Tran, Huy Dat; Kitaoka, Norihide; Li, Haizhou

    Conventional features for Automatic Speech Recognition and Sound Event Recognition such as Mel-Frequency Cepstral Coefficients (MFCCs) have been shown to perform poorly in noisy conditions. We introduce an auditory feature based on the gammatone filterbank, the Selective Gammatone Envelope Feature (SGEF), for Robust Sound Event Recognition where channel selection and the filterbank envelope is used to reduce the effect of noise for specific noise environments. In the experiments with Hidden Markov Model (HMM) recognizers, we shall show that our feature outperforms MFCCs significantly in four different noisy environments at various signal-to-noise ratios.

  17. Oocytes as an experimental system to analyze the ultrastructure of endogenous and ectopically expressed nuclear envelope components by field-emission scanning electron microscopy.

    Science.gov (United States)

    Stick, Reimer; Goldberg, Martin W

    2010-05-01

    Xenopus oocytes provide a powerful model system for studying the structure and function of the nuclear envelope and its components. Firstly, the nuclear envelope is easily isolated by hand under gentle conditions that have little effect on its structural organization. They can then be prepared for several types of electron microscopy (EM) including field-emission scanning EM (feSEM) (described here) and cryo-EM. They can be immuno-gold labeled to determine the localization of individual proteins. There is also enough material to analyze biochemically. Secondly, they possess an efficient transcription and translation system so that proteins of interest can be ectopically expressed by injection of either mRNA into the cytoplasm or plasmids into the nucleus. Such proteins can be tagged and mutated. They are post-translationally modified and usually incorporate into the correct compartment. We describe here methods developed to analyze the structural organization of the nuclear envelope by feSEM including the structural organization of ectopically expressed nuclear envelope proteins.

  18. HIV-1 envelope glycoprotein resistance to monoclonal antibody 2G12 is subject-specific and context-dependent in macaques and humans

    NARCIS (Netherlands)

    Malherbe, Delphine C.; Sanders, Rogier W.; van Gils, Marit J.; Park, Byung; Gomes, Michelle M.; Schuitemaker, Hanneke; Barnett, Susan; Haigwood, Nancy L.

    2013-01-01

    HIV-1 Envelope (Env) protein is the sole target of neutralizing antibodies (NAbs) that arise during infection to neutralize autologous variants. Under this immune pressure, HIV escape variants are continuously selected and over the course of infection Env becomes more neutralization resistant. Many

  19. cGMP production and analysis of BG505 SOSIP.664, an extensively glycosylated, trimeric HIV-1 envelope glycoprotein vaccine candidate

    NARCIS (Netherlands)

    dey, Antu K.; Cupo, Albert; Ozorowski, Gabriel; Sharma, Vaneet K.; Behrens, Anna-Janina; Go, Eden P.; Ketas, Thomas J.; Yasmeen, Anila; Klasse, Per J.; Sayeed, Eddy; Desaire, Heather; Crispin, Max; Wilson, Ian A.; Sanders, Rogier W.; Hassell, Thomas; Ward, Andrew; Moore, John P.

    2017-01-01

    We describe the properties of BG505 SOSIP.664 HIV-1 envelope glycoprotein trimers produced under current Good Manufacturing Practice (cGMP) conditions. These proteins are the first of a new generation of native-like trimers that are the basis for many structure-guided immunogen development programs

  20. Tracking down the ZP domain: From the mammalian zona pellucida to the molluscan vitelline envelope.

    Science.gov (United States)

    Monné, Magnus; Han, Ling; Jovine, Luca

    2006-09-01

    Oocytes from virtually all organisms are surrounded by at least one coat. This specialized extracellular matrix, called the zona pellucida (ZP) in mammals and the vitelline envelope (VE) in nonmammals, has a structural function and plays essential roles in oogenesis, fertilization, and early development. During the last 15 years, compelling evidence has accumulated that all ZP/VE subunits polymerize using a conserved sequence, the ZP domain, so that the basic structural features of egg coat matrices have been maintained through evolution. Moreover, ZP domains have been identified in many other polymeric extracellular proteins from eukaryotes. This review compares the ultrastructure and molecular composition of egg coats from mollusc to human, suggests a common mechanism for assembly of ZP/VE proteins, and discusses alternative models of how these could be arranged within filaments.

  1. Printing of the year book, carton boxes and printed envelopes

    Indian Academy of Sciences (India)

    2018-01-18

    Jan 18, 2018 ... 1. Title: PRINTING AND SUPPLY OF THE YEAR BOOK - 2018 AND CARTON BOXES ALONG WITH PRINTED. ENVELOPES. Description a) Book size: : 140 X 215 mm / 22.5 cm x 15 cm (Trim Size) b) No. of Pages. : 340 + 4 in DOUBLE COLOUR c) Inner Pages. Matt Art 100 GSM. 2) Natural shade (NS), ...

  2. Access envelopes: A new accessibility mapping technique for ...

    African Journals Online (AJOL)

    The article describes the application of a GIS-based accessibility measurement technique suited to assessing the impact of both transport and spatial development strategies on the location-specific affordability of job access for poor households. The access envelope methodology extends existing accessibility measures by: ...

  3. Application of sand and geotextile envelope in subsurface drip ...

    African Journals Online (AJOL)

    TUOYO

    2010-08-09

    Aug 9, 2010 ... Application of sand and geotextile envelope in subsurface drip irrigation. P. Najafi* and S. H. Tabatabaei. 1Islamic Azad University, Khorasgan Branch, P.O. 81595-158, Isfahan, Iran. 2Department of Water Engineering, Faculty of Agriculture, Shahrekord University, Shahrekord, Iran. Accepted 7 June, 2010.

  4. Magnetically Targeted Viral Envelopes: A PET Investigation of Initial Biodistribution

    Science.gov (United States)

    Flexman, Jennifer A.; Cross, Donna J.; Lewellen, Barbara L.; Miyoshi, Sosuke; Kim, Yongmin

    2009-01-01

    Gene and drug therapy for organ-specific diseases in part depends on the efficient delivery to a particular region of the body. We examined the biodistribution of a viral envelope commonly used as a nanoscale gene delivery vehicle using positron emission tomography (PET) and investigated the magnetic alteration of its biodistribution. Iron oxide nanoparticles and 18 F-fluoride were encapsulated by hemagglutinating virus of Japan envelopes (HVJ-Es). HVJ-Es were then injected intravenously in the rat and imaged dynamically using high-resolution PET. Control subjects received injections of encapsulated materials alone. For magnetic targeting, permanent magnets were fixed on the head during the scan. Based on the quantitative analysis of PET images, HVJ-Es accumulated in the liver and spleen and activity remained higher than control subjects for 2 h. Histological sections of the liver confirmed imaging findings. Pixel-wise activity patterns on coregistered PET images of the head showed a significantly different pattern for the subjects receiving magnetic targeting as compared to all control groups. Imaging demonstrated the initial biodistribution of a viral envelope within the rodent by providing quantitative behavior over time and in specific anatomical regions. Magnetic force altered the biodistribution of the viral envelope to a target structure, and could enable region-specific delivery of therapeutic vehicles noninvasively. PMID:18779103

  5. AM Envelope : The Potential of Additive Manufacturing for facade constructions

    NARCIS (Netherlands)

    Strauss, H.

    2013-01-01

    The continuous development of the building envelope over the past hundred years can be exemplified by a few ground-breaking inventions. Firstly, the separation of primary and secondary structure during the beginning of the 20th century; by implementing a curtain wall façade to physically separate

  6. Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

    African Journals Online (AJOL)

    The E glycoprotein of dengue virus is responsible for the viral binding to the receptor. The crystal structure of envelope glycoprotein has already been determined. However, where the well-defined Bcell and T-cell epitopes are located is still a question. Because of the large variations among the four dengue genotypes, it is ...

  7. Enveloped virus-like particles as vaccines against pathogenic arboviruses

    NARCIS (Netherlands)

    Pijlman, G.P.

    2015-01-01

    Arthropod-borne arboviruses form a continuous threat to human and animal health, but few arboviral vaccines are currently available. Advances in expression technology for complex, enveloped virus-like particles (eVLPs) create new opportunities to develop potent vaccines against pathogenic

  8. 10 CFR 434.402 - Building envelope assemblies and materials.

    Science.gov (United States)

    2010-01-01

    ... design condition. For shell buildings, the permitted skylight area shall be based on a light level of 30... 10 Energy 3 2010-01-01 2010-01-01 false Building envelope assemblies and materials. 434.402... MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Design Requirements-Electric Systems and Equipment...

  9. Neural coding of sound envelope structure in songbirds.

    Science.gov (United States)

    Boari, Santiago; Amador, Ana

    2017-12-12

    Songbirds are a well-established animal model to study the neural basis of learning, perception and production of complex vocalizations. In this system, telencephalic neurons in HVC present a state-dependent, highly selective response to auditory presentations of the bird's own song (BOS). This property provides an opportunity to study the neural code behind a complex motor behavior. In this work, we explore whether changes in the temporal structure of the sound envelope can drive changes in the neural responses of highly selective HVC units. We generated an envelope-modified BOS (MOD) by reversing each syllable's envelope but leaving the overall temporal structure of syllable spectra unchanged, which resulted in a subtle modification for each song syllable. We conducted in vivo electrophysiological recordings of HVC neurons in anaesthetized zebra finches (Taeniopygia guttata). Units analyzed presented a high BOS selectivity and lower response to MOD, but preserved the profile response shape. These results show that the temporal evolution of the sound envelope is being sensed by the avian song system and suggest that the biomechanical properties of the vocal apparatus could play a role in enhancing subtle sound differences.

  10. Fault diagnosis in gear using wavelet envelope power spectrum ...

    African Journals Online (AJOL)

    An experimental data set is used to compare the diagnostic capability of the fast Fourier transform power spectrum to the wavelet envelope power spectrum as respectively computed using Laplace and Morlet wavelet functions. The gear testing apparatus was used for experimental studies to obtain the vibration signal from ...

  11. Masking Release for Sweeping Masker Components with Correlated Envelopes

    DEFF Research Database (Denmark)

    Verhey, Jesko l.; Klein-Hennig, Hendrike; Epp, Bastian

    2013-01-01

    To separate sounds from different sound sources, common properties of natural sounds are used by the auditory system, such as coherent temporal envelope fluctuations and correlated changes of frequency in different frequency regions. The present study investigates how the auditory systemprocesses...

  12. Spectral Envelope Transformation in Singing Voice for Advanced Pitch Shifting

    Directory of Open Access Journals (Sweden)

    José L. Santacruz

    2016-11-01

    Full Text Available The aim of the present work is to perform a step towards more natural pitch shifting techniques in singing voice for its application in music production and entertainment systems. In this paper, we present an advanced method to achieve natural modifications when applying a pitch shifting process to singing voice by modifying the spectral envelope of the audio excerpt. To this end, an all-pole model has been selected to model the spectral envelope, which is estimated using a constrained non-linear optimization. The analysis of the global variations of the spectral envelope was carried out by identifying changes of the parameters of the model along with the changes of the pitch. With the obtained spectral envelope transformation functions, we applied our pitch shifting scheme to some sustained vowels in order to compare results with the same transformation made by using the Flex Pitch plugin of Logic Pro X and pitch synchronous overlap and add technique (PSOLA. This comparison has been carried out by means of both an objective and a subjective evaluation. The latter was done with a survey open to volunteers on our website.

  13. Hygrothermal Simulation: A Tool for Building Envelope Design Analysis

    Science.gov (United States)

    Samuel V. Glass; Anton TenWolde; Samuel L. Zelinka

    2013-01-01

    Is it possible to gauge the risk of moisture problems while designing the building envelope? This article provides a brief introduction to computer-based hygrothermal (heat and moisture) simulation, shows how simulation can be useful as a design tool, and points out a number of im-portant considerations regarding model inputs and limita-tions. Hygrothermal simulation...

  14. Comparative Study of Two Multilevel Converters for Envelope Amplifier

    Directory of Open Access Journals (Sweden)

    Miroslav Vasić

    2010-06-01

    Full Text Available Modern transmitters usually have to amplify and transmit signals with simultaneous envelope and phase modulation. Due to this property of the transmitted signal, linear power amplifiers (class A, B or AB are usually used as a solution for the power amplifier stage. These amplifiers have high linearity, but suffer from low efficiency when the transmitted signal has low peak-to-average power ratio. The Kahn envelope elimination and restoration (EER technique is used to enhance efficiency of RF transmitters, by combining highly efficient,nonlinear RF amplifier (class D or E with a highly efficient envelope amplifier in order to obtain linear and highly efficientRF amplifier. This paper compares two solutions for the envelope amplifier based on a combination of multilevel converter and linear regulator. The solutions are compared regarding their efficiency, size and weight. Both solutions can reproduce any signal with maximal spectral component of 2 MHz and give instantaneous maximal power of 50 W. The efficiency measurements show that when the signals with low average value are transmitted, the implemented prototypes have up to 20% higher efficiency than linear regulator that is used as a conventional solution.

  15. Envelope-Law and Geometric-Mean STAP Detection

    NARCIS (Netherlands)

    Anitori, L.; Srinivasan, R.; Rangaswamy, M.

    2010-01-01

    Two detectors for space-time adaptive processing (STAP) are proposed here. These are variants that use envelope-law and geometric-mean (GM) (or logarithmic) processing, both being well-known concepts from conventional constant false alarm rate (CFAR) square-law radar detection [212]. The variants

  16. Print and supply of envelopes and file covers

    Indian Academy of Sciences (India)

    The Financial bids would be sealed by the bidder in separate covers duly superscribed & both these. Sealed covers are to be put in a bigger cover which should also be sealed & duly Super scribed with. Tender for Supply of Printed Envelopes and File Covers. Tender documents can be downloaded from IASc Website ...

  17. Efficient delivery of antibody into living cells using a novel HVJ envelope vector system.

    Science.gov (United States)

    Kondo, Yoshitaka; Fushikida, Kuni; Fujieda, Takayuki; Sakai, Kimie; Miyata, Keizo; Kato, Fuminori; Kato, Masanari

    2008-03-20

    Introduction of antibodies which retain their function into cells using a simple and easy method would be very useful for study of the intracellular events in living cells. In this study, we developed a new method for intracellular delivery of antibody. It includes a combination of a novel IgG-capturing protein and hemagglutinating virus of Japan envelope (HVJ-E), an inactivated Sendai virus particle which can deliver a variety of molecules into mammalian cells via membrane-fusing activity. The IgG-capturing protein, which was molecularly designed to have two functions, was prepared as a fusion protein (ZZ-NP) of ZZ-dimer derived from an immunoglobulin-binding domain of protein A and nucleocapsid protein (NP), a part of the structural protein of HVJ. ZZ-NP was efficiently incorporated into the HVJ-E particle by treatment with detergent, and enhanced the incorporation of IgG. Moreover, fluorescence immunostaining revealed that the incorporated antibody was very efficiently introduced into living cells while retaining its function, i.e. anti-NPC (nuclear pore complex) monoclonal antibody was selectively located around cell nuclei. These findings suggest that this method is useful for intracellular delivery of antibody and for analysis of biological function of sub-cellular molecules in living cells.

  18. Dynamic Flight Envelope Assessment with Flight Safety Applications

    Science.gov (United States)

    Pandita, Rohit

    Aircraft have a manufacturer prescribed operating flight envelope for safe operation, exceeding these limits can result in unrecoverable departures or even structural failure. Numerous commercial aircraft accidents in the past have been attributed to loss-of-control (LOC) resulting from exceeding the safe operating flight envelope. Hence, real-time knowledge of the safe operating flight envelope is essential for safe flight operation, a problem known as dynamic flight envelope assessment. This dissertation explores dynamic flight envelope assessment from a control theoretic perspective. Two notions of the flight envelope, namely, the reachable sets and the region-of-attraction analysis are investigated. The NASA generic transport model (GTM) aircraft dynamics is used as an application problem. Linear and nonlinear techniques for flight envelope assessment are formulated in the linear matrix inequality (LMI) and sum-of-squares (SOS) framework, respectively. LMI and SOS problems are computationally tractable convex optimization problems for which many semi-definite programming solvers are available. This thesis also investigated fault detection and isolation strategies. Commercial jet transport aircrafts make extensive use of active controls. Faults or failures in the flight control system (FCS) elements like sensors or control effectors can lead to catastrophic failure. Model-based fault detection and isolation (FDI) filters can provide analytical redundancy by reliably detecting such faults in the system. Practical application of model-based FDI filters is limited so far due to poor performance, false alarms and missed detection arising out of uncertain dynamics of the aircraft, effect of nonlinearities in the system and the influence of closed-loop controllers. An application of closed-loop metrics to assess worst case FDI filter performance in the presence of a controller and uncertain dynamics is presented. Longitudinal GTM dynamics are considered. An Hinfinity

  19. GPI-anchored single chain Fv - an effective way to capture transiently-exposed neutralization epitopes on HIV-1 envelope spike

    Directory of Open Access Journals (Sweden)

    Kimata Jason T

    2010-10-01

    Full Text Available Abstract Background Identification of broad neutralization epitopes in HIV-1 envelope spikes is paramount for HIV-1 vaccine development. A few broad neutralization epitopes identified so far are present on the surface of native HIV-1 envelope spikes whose recognition by antibodies does not depend on conformational changes of the envelope spikes. However, HIV-1 envelope spikes also contain transiently-exposed neutralization epitopes, which are more difficult to identify. Results In this study, we constructed single chain Fvs (scFvs derived from seven human monoclonal antibodies and genetically linked them with or without a glycosyl-phosphatidylinositol (GPI attachment signal. We show that with a GPI attachment signal the scFvs are targeted to lipid rafts of plasma membranes. In addition, we demonstrate that four of the GPI-anchored scFvs, but not their secreted counterparts, neutralize HIV-1 with various degrees of breadth and potency. Among them, GPI-anchored scFv (X5 exhibits extremely potent and broad neutralization activity against multiple clades of HIV-1 strains tested. Moreover, we show that GPI-anchored scFv (4E10 also exhibited more potent neutralization activity than its secretory counterpart. Finally, we demonstrate that expression of GPI-anchored scFv (X5 in the lipid raft of plasma membrane of human CD4+ T cells confers long-term resistance to HIV-1 infection, HIV-1 envelope-mediated cell-cell fusion, and the infection of HIV-1 captured and transferred by human DCs. Conclusions Thus GPI-anchored scFv could be used as a general and effective way to identify antibodies that react with transiently-exposed neutralization epitopes in envelope proteins of HIV-1 and other enveloped viruses. The GPI-anchored scFv (X5, because of its breadth and potency, should have a great potential to be developed into anti-viral agent for HIV-1 prevention and therapy.

  20. Proteomics on the rims: insights into the biology of the nuclear envelope and flagellar pocket of trypanosomes.

    Science.gov (United States)

    Field, Mark C; Adung'a, Vincent; Obado, Samson; Chait, Brian T; Rout, Michael P

    2012-08-01

    Trypanosomatids represent the causative agents of major diseases in humans, livestock and plants, with inevitable suffering and economic hardship as a result. They are also evolutionarily highly divergent organisms, and the many unique aspects of trypanosome biology provide opportunities in terms of identification of drug targets, the challenge of exploiting these putative targets and, at the same time, significant scope for exploration of novel and divergent cell biology. We can estimate from genome sequences that the degree of divergence of trypanosomes from animals and fungi is extreme, with perhaps one third to one half of predicted trypanosome proteins having no known function based on homology or recognizable protein domains/architecture. Two highly important aspects of trypanosome biology are the flagellar pocket and the nuclear envelope, where in silico analysis clearly suggests great potential divergence in the proteome. The flagellar pocket is the sole site of endo- and exocytosis in trypanosomes and plays important roles in immune evasion via variant surface glycoprotein (VSG) trafficking and providing a location for sequestration of various invariant receptors. The trypanosome nuclear envelope has been largely unexplored but, by analogy with higher eukaryotes, roles in the regulation of chromatin and most significantly, in controlling VSG gene expression are expected. Here we discuss recent successful proteomics-based approaches towards characterization of the nuclear envelope and the endocytic apparatus, the identification of conserved and novel trypanosomatid-specific features, and the implications of these findings.

  1. Redirecting the Cyanobacterial Bicarbonate Transporters BicA and SbtA to the Chloroplast Envelope: Soluble and Membrane Cargos Need Different Chloroplast Targeting Signals in Plants.

    Directory of Open Access Journals (Sweden)

    Vivien eRolland

    2016-02-01

    Full Text Available Most major crops used for human consumption are C3 plants, which yields are limited by photosynthetic inefficiency. To circumvent this, it has been proposed to implement the cyanobacterial CO2-concentrating mechanism (CCM, principally consisting of bicarbonate transporters and carboxysomes, into plant chloroplasts. As it is currently not possible to recover homoplasmic transplastomic monocots, foreign genes must be introduced in these plants via nuclear transformation. Consequently, it is paramount to ensure that resulting proteins reach the appropriate sub-cellular compartment, which for cyanobacterial transporters BicA and SbtA, is the chloroplast inner-envelope membrane (IEM. At present, targeting signals to redirect large transmembrane proteins from non-chloroplastic organisms to plant chloroplast envelopes are unknown. The goal of this study was to identify such signals, using agrobacteria-mediated transient expression and confocal microscopy to determine the sub-cellular localization of ~37 GFP-tagged chimeras. Initially, fragments of chloroplast proteins known to target soluble cargos to the stroma were tested for their ability to redirect BicA, but they proved ineffective. Next, different N-terminal regions from Arabidopsis IEM transporters were tested. We demonstrated that the N-terminus of AtHP59, AtPLGG1 or AtNTT1 (92-115 amino acids, containing a cleavable chloroplast transit peptide (cTP and a membrane protein leader (MPL, was sufficient to redirect BicA or SbtA to the chloroplast envelope. This constitutes the first evidence that nuclear-encoded transmembrane proteins from non-chloroplastic organisms can be targeted to the envelope of plant chloroplasts; a finding which represents an important advance in chloroplast engineering by opening up the door to further manipulation of the chloroplastic envelope.

  2. Probability distributions of the electroencephalogram envelope of preterm infants.

    Science.gov (United States)

    Saji, Ryoya; Hirasawa, Kyoko; Ito, Masako; Kusuda, Satoshi; Konishi, Yukuo; Taga, Gentaro

    2015-06-01

    To determine the stationary characteristics of electroencephalogram (EEG) envelopes for prematurely born (preterm) infants and investigate the intrinsic characteristics of early brain development in preterm infants. Twenty neurologically normal sets of EEGs recorded in infants with a post-conceptional age (PCA) range of 26-44 weeks (mean 37.5 ± 5.0 weeks) were analyzed. Hilbert transform was applied to extract the envelope. We determined the suitable probability distribution of the envelope and performed a statistical analysis. It was found that (i) the probability distributions for preterm EEG envelopes were best fitted by lognormal distributions at 38 weeks PCA or less, and by gamma distributions at 44 weeks PCA; (ii) the scale parameter of the lognormal distribution had positive correlations with PCA as well as a strong negative correlation with the percentage of low-voltage activity; (iii) the shape parameter of the lognormal distribution had significant positive correlations with PCA; (iv) the statistics of mode showed significant linear relationships with PCA, and, therefore, it was considered a useful index in PCA prediction. These statistics, including the scale parameter of the lognormal distribution and the skewness and mode derived from a suitable probability distribution, may be good indexes for estimating stationary nature in developing brain activity in preterm infants. The stationary characteristics, such as discontinuity, asymmetry, and unimodality, of preterm EEGs are well indicated by the statistics estimated from the probability distribution of the preterm EEG envelopes. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. The psychic envelopes in psychoanalytic theories of infancy.

    Science.gov (United States)

    Mellier, Denis

    2014-01-01

    This paper aims to review the topic of psychic envelopes and to sketch the main outlines of this concept in infancy. We first explore the origins of the concept in Freud's "protective shield" and then its development in adult psychoanalysis before going on to see how this fits in infancy with post-Bionian psychoanalysis and development. Four central notions guide this review: (1) Freud's "protective shield" describes a barrier to protect the psychic apparatus against potentially overflowing trauma. It is a core notion which highlights a serious clinical challenge for patients for whom the shield is damaged or faulty: the risk of confusion of borders between the internal/external world, conscious/unconscious, mind/body, or self-conservation/sexuality. (2) Anzieu's "Skin-Ego" is defined by the different senses of the body. The different layers of experienced sensation, of this body-ego, go on to form the psychic envelope. This theory contributes to our understanding of how early trauma, due to the failures of maternal care, can continue to have an impact in adult life. (3) Bick's "psychic skin" establishes the concept in relation to infancy. The mother's containing functions allow a first psychic skin to develop, which then defines an infant's psychic space and affords the infant a degree of self-containment. Houzel then conceptualized this process as a stabilization of drive forces. (4) Stern's "narrative envelope" derives from the intersection between psychoanalysis and neuroscience. It gives us another way to conceptualize the development of pre-verbal communication. It may also pave the way for a finer distinction of different types of envelopes. Ultimately, in this review we find that psychic envelopes in infancy can be viewed from four different perspectives (economic, topographical, dynamic, and genetic) and recommend further investigation.

  4. The psychic envelopes in psychoanalytic theories of infancy.

    Directory of Open Access Journals (Sweden)

    Denis eMellier

    2014-07-01

    Full Text Available This paper aims to review the topic of psychic envelopes and to sketch the main outlines of this concept in infancy. We first explore the origins of the concept in Freud's 'protective shield' and then its development in adult psychoanalysis before going on to see how this fits in infancy with post-Bionian psychoanalysis and development. Four central notions guide this review:1 Freud's protective shield describes a barrier to protect the psychic apparatus against potentially overflowing trauma. It is a core notion which highlights a serious clinical challenge for patients for whom the shield is damaged or faulty: the risk of confusion of borders between the internal/external world, conscious/unconscious, mind/body, or self-conservation/sexuality.2 Anzieu's Skin-Ego is defined by the different senses of the body. The different layers of experienced sensation, of this body-ego, go on to form the psychic envelope. This theory contributes to our understanding of how early trauma, due to the failures of maternal care, can continue to have an impact in adult life. 3 Bick's psychic skin establishes the concept in relation to infancy. The mother’s containing functions allow a first psychic skin to develop, which then defines an infant’s psychic space and affords the infant a degree of self-containment. Houzel then conceptualized this process as a stabilization of drive forces.4 Stern's narrative envelope derives from the intersection between psychoanalysis and neuroscience. It gives us another way to conceptualise the development of pre-verbal communication. It may also pave the way for a finer distinction of different types of envelopes.Ultimately, in this review we find that psychic envelopes in infancy can be viewed from four different perspectives (economic, topographical, dynamic and genetic and recommend further investigation.

  5. Dansyl chloride labeling of Pseudomonas aeruginosa treated with pyocin R1: change in permeability of the cell envelope.

    Science.gov (United States)

    Uratani, Y

    1982-01-01

    Pyocin R1, a bacteriocin of Pseudomonas aeruginosa, caused an increase in binding of fluorescent label, 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride), to sensitive cells. In pyocin R1-treated cells, cytoplasmic soluble proteins and crude ribosomes as well as cell envelopes were labeled by dansyl chloride. The amount of bound dye was proportional to the multiplicity of pyocin R1 and reached a maximal level at high multiplicity. In addition, pyocin R1 rapidly caused an increase in fluorescence intensity of the hydrophobic probes N-phenyl-1-naphthylamine, pyrene, and perylene, which were mixed with cells. These results show that pyocin R1 damages locally a cell envelope barrier to hydrophobic solutes and allows dyes to penetrate into the intracellular space across the barrier. PMID:6799489

  6. Early localization of NPA58, a rat nuclear pore-associated protein, to ...

    Indian Academy of Sciences (India)

    The targeting of NPA58 to the reforming nuclear envelope in early telophase coincides with the recruitment of a well-characterized class of nuclear pore proteins recognized by the antibody mAb 414, and occurs prior to the incorporation of lamin B1 into the envelope. Significant protein import activity is detectable only after ...

  7. Building Envelope for New Buildings and Energy Renovation of Old Buildings

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian

    1997-01-01

    The Building Envelope Project at Technical University of Denmark should, in coorporation with associated trade organizations, strengthen the development on the building envelope area with focus on heat, moisture and economy...

  8. Regulation of nuclear envelope dynamics via APC/C is necessary for the progression of semi-open mitosis in Schizosaccharomyces japonicus.

    Science.gov (United States)

    Aoki, Keita; Shiwa, Yuh; Takada, Hiraku; Yoshikawa, Hirofumi; Niki, Hironori

    2013-09-01

    Three types of mitosis, which are open, closed or semi-open mitosis, function in eukaryotic cells, respectively. The open mitosis involves breakage of the nuclear envelope before nuclear division, whereas the closed mitosis proceeds with an intact nuclear envelope. To understand the mechanism and significance of three types of mitotic division in eukaryotes, we investigated the process of semi-open mitosis, in which the nuclear envelope is only partially broken, in the fission yeast Schizosaccharomyces japonicus. In anaphase-promoting complex/cyclosome (APC/C) mutants of Sz. japonicus, the nuclear envelope remained relatively intact during anaphase, resulting in impaired semi-open mitosis. As a suppressor of apc2 mutant, a mutation of Oar2, which was a 3-oxoacyl-[acyl carrier protein] reductase, was obtained. The level of the Oar2, which had two destruction-box motifs recognized by APC/C, was increased in APC/C mutants. Furthermore, the defective semi-open mitosis observed in an apc2 mutant was restored by mutated oar2+. Based on these findings, we propose that APC/C regulates the dynamics of the nuclear envelope through degradation of Oar2 dependent on APC/C during the metaphase-to-anaphase transition of semi-open mitosis in Sz. japonicus. © 2013 The Authors Genes to Cells © 2013 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  9. A simple one-step method for the preparation of HIV-1 envelope glycoprotein immunogens based on a CD4 mimic peptide.

    Science.gov (United States)

    Martin, Grégoire; Sun, Yide; Heyd, Bernadette; Combes, Olivier; Ulmer, Jeffrey B; Descours, Anne; Barnett, Susan W; Srivastava, Indresh K; Martin, Loïc

    2008-11-25

    To counteract the problems associated with the purification of HIV envelope, we developed a new purification method exploiting the high affinity of a peptide mimicking CD4 towards the viral glycoprotein. This miniCD4 was used as a ligand in affinity chromatography and allowed the separation in one step of HIV envelope monomer from cell supernatant and the capture of pre-purified trimer. This simple and robust method of purification yielded to active and intact HIV envelopes as proved by the binding of CCR5 HIV co-receptor, CD4 and a panel of well-characterized monoclonal antibodies. The immunogenicity of miniCD4-purified HIV envelope was further assessed in rats. The analysis of the humoral response indicated that elicited antibodies were able to recognize a broad range of HIV envelopes. Finally, this method based on a chemically synthesized peptide may represent a convenient and versatile tool for protein purification compatible far scale-up in both academic and pharmaceutical researches.

  10. AM Envelope. The potential of Additive Manufacturing for facade constructions

    Directory of Open Access Journals (Sweden)

    Holger Strauss

    2017-11-01

    Full Text Available This dissertation shows the potential of Additive Manufacturing (AM for the development of building envelopes: AM will change the way of designing facades, how we engineer and produce them. To achieve today’s demands from those future envelopes, we have to find new solutions. New technologies offer one possible way to do so. They open new approaches in designing, producing and processing building construction and facades. Finding the one capable of having big impact is difficult – Additive Manufacturing is one possible answer. The term ‘AM Envelope’ (Additive Manufacturing Envelope describes the transfer of this technology to the building envelope. Additive Fabrication is a building block that aids in developing the building envelope from a mere space enclosure to a dynamic building envelope. First beginnings of AM facade construction show up when dealing with relevant aspects like material consumption, mounting or part’s performance. From those starting points several parts of an existing post-and-beam façade system were optimized, aiming toward the implementation of AM into the production chain. Enhancements on all different levels of production were achieved: storing, producing, mounting and performance. AM offers the opportunity to manufacture facades ‘just in time’. It is no longer necessary to store or produce large numbers of parts in advance. Initial investment for tooling can be avoided, as design improvements can be realized within the dataset of the AM part. AM is based on ‘tool-less’ production, all parts can be further developed with every new generation. Producing tool-less also allows for new shapes and functional parts in small batch sizes – down to batch size one. The parts performance can be re-interpreted based on the demands within the system, not based on the limitations of conventional manufacturing. AM offers new ways of materializing the physical part around its function. It leads toward customized

  11. AM Envelope. The potential of Additive Manufacturing for facade constructions

    Directory of Open Access Journals (Sweden)

    Holger Strauss

    2013-02-01

    Full Text Available This dissertation shows the potential of Additive Manufacturing (AM for the development of building envelopes: AM will change the way of designing facades, how we engineer and produce them. To achieve today’s demands from those future envelopes, we have to find new solutions.New technologies offer one possible way to do so. They open new approaches in designing, producing and processing building construction and facades. Finding the one capable of having big impact is difficult – Additive Manufacturing is one possible answer.The term ‘AM Envelope’ (Additive Manufacturing Envelope describes the transfer of this technology to the building envelope. Additive Fabrication is a building block that aids in developing the building envelope from a mere space enclosure to a dynamic building envelope.First beginnings of AM facade construction show up when dealing with relevant aspects like material consumption, mounting or part’s performance.From those starting points several parts of an existing post-and-beam façade system were optimized, aiming toward the implementation of AM into the production chain. Enhancements on all different levels of production were achieved: storing, producing, mounting and performance.AM offers the opportunity to manufacture facades ‘just in time’. It is no longer necessary to store or produce large numbers of parts in advance. Initial investment for tooling can be avoided, as design improvements can be realized within the dataset of the AM part. AM is based on ‘tool-less’ production, all parts can be further developed with every new generation.Producing tool-less also allows for new shapes and functional parts in small batch sizes – down to batch size one. The parts performance can be re-interpreted based on the demands within the system, not based on the limitations of conventional manufacturing. AM offers new ways of materializing the physical part around its function. It leads toward customized and

  12. The HVJ-envelope as an innovative vector system for cardiovascular disease.

    Science.gov (United States)

    Kotani, Hitoshi; Nakajima, Toshihiro; Lai, Shoupeng; Morishita, Ryuichi; Kaneda, Yasufumi

    2004-06-01

    Recently promising results of gene therapy clinical trials have been reported for treatment of peripheral vascular and cardiovascular diseases using various angiogenic growth factors and other therapeutic genes. Viral vector and non-viral vector systems were employed in preclinical studies and clinical trials. Adenoviral vector and naked plasmid have been used most in the clinical studies. HVJ (hemagglutinating virus of Japan or Sendai virus)-liposome vector, a hybrid non-viral vector system with fusion of inactivated HVJ virus particle and liposome, has developed and demonstrated high transfection efficiency in preclinical studies of many different disease models, including a wide range of cardiovascular disease models. However, some limitations exist in the HVJ-liposome technology, especially in the scalability of its production. Recently an innovative vector technology, HVJ envelope (HVJ-E) has been developed as a non-viral vector, consisting of HVJ envelope without its viral genome, which is eliminated by a combination of inactivation and purification steps. HVJ-E is able to enclose various molecule entities, including DNA, oligonucleotides, proteins, as single or multiple therapeutic remedies. The therapeutic molecule-included HVJ-E vector can transfect various cell types in animals and humans with high efficiency. In this review, vector technology for cardiovascular disease and the biology of HVJ-E vector technology is discussed.

  13. A coherent mathematical characterization of isotope trace extraction, isotopic envelope extraction, and LC-MS correspondence

    Science.gov (United States)

    2015-01-01

    Background Liquid chromatography-mass spectrometry is a popular technique for high-throughput protein, lipid, and metabolite comparative analysis. Such statistical comparison of millions of data points requires the generation of an inter-run correspondence. Though many techniques for generating this correspondence exist, few if any, address certain well-known run-to-run LC-MS behaviors such as elution order swaps, unbounded retention time swaps, missing data, and significant differences in abundance. Moreover, not all extant correspondence methods leverage the rich discriminating information offered by isotope envelope extraction informed by isotope trace extraction. To date, no attempt has been made to create a formal generalization of extant algorithms for these problems. Results By enumerating extant objective functions for these problems, we elucidate discrepancies between known LC-MS data behavior and extant approaches. We propose novel objective functions that more closely model known LC-MS behavior. Conclusions Through instantiating the proposed objective functions in the form of novel algorithms, practitioners can more accurately capture the known behavior of isotope traces, isotopic envelopes, and replicate LC-MS data, ultimately providing for improved quantitative accuracy. PMID:25951936

  14. Efficient Strategy to Generate a Vectored Duck Enteritis Virus Delivering Envelope of Duck Tembusu Virus

    Directory of Open Access Journals (Sweden)

    Zhong Zou

    2014-06-01

    Full Text Available Duck Tembusu virus (DTMUV is a recently emerging pathogenic flavivirus that has resulted in a huge economic loss in the duck industry. However, no vaccine is currently available to control this pathogen. Consequently, a practical strategy to construct a vaccine against this pathogen should be determined. In this study, duck enteritis virus (DEV was examined as a candidate vaccine vector to deliver the envelope (E of DTMUV. A modified mini-F vector was inserted into the SORF3 and US2 gene junctions of the attenuated DEV vaccine strain C-KCE genome to generate an infectious bacterial artificial chromosome (BAC of C-KCE (vBAC-C-KCE. The envelope (E gene of DTMUV was inserted into the C-KCE genome through the mating-assisted genetically integrated cloning (MAGIC strategy, resulting in the recombinant vector, pBAC-C-KCE-E. A bivalent vaccine C-KCE-E was generated by eliminating the BAC backbone. Immunofluorescence and western blot analysis results indicated that the E proteins were vigorously expressed in C-KCE-E-infected chicken embryo fibroblasts (CEFs. Duck experiments demonstrated that the insertion of the E gene did not alter the protective efficacy of C-KCE. Moreover, C-KCE-E-immunized ducks induced neutralization antibodies against DTMUV. These results demonstrated, for the first time, that recombinant C-KCE-E can serve as a potential bivalent vaccine against DEV and DTMUV.

  15. Brucella abortus choloylglycine hydrolase affects cell envelope composition and host cell internalization.

    Science.gov (United States)

    Marchesini, María Inés; Connolly, Joseph; Delpino, María Victoria; Baldi, Pablo C; Mujer, Cesar V; DelVecchio, Vito G; Comerci, Diego J

    2011-01-01

    Choloylglycine hydrolase (CGH, E.C. 3.5.1.24) is a conjugated bile salt hydrolase that catalyses the hydrolysis of the amide bond in conjugated bile acids. Bile salt hydrolases are expressed by gastrointestinal bacteria, and they presumably decrease the toxicity of host's conjugated bile salts. Brucella species are the causative agents of brucellosis, a disease affecting livestock and humans. CGH confers Brucella the ability to deconjugate and resist the antimicrobial action of bile salts, contributing to the establishment of a successful infection through the oral route in mice. Additionally, cgh-deletion mutant was also attenuated in intraperitoneally inoculated mice, which suggests that CGH may play a role during systemic infection other than hydrolyzing conjugated bile acids. To understand the role CGH plays in B. abortus virulence, we infected phagocytic and epithelial cells with a cgh-deletion mutant (Δcgh) and found that it is defective in the internalization process. This defect along with the increased resistance of Δcgh to the antimicrobial action of polymyxin B, prompted an analysis of the cell envelope of this mutant. Two-dimensional electrophoretic profiles of Δcgh cell envelope-associated proteins showed an altered expression of Omp2b and different members of the Omp25/31 family. These results were confirmed by Western blot analysis with monoclonal antibodies. Altogether, the results indicate that Brucella CGH not only participates in deconjugation of bile salts but also affects overall membrane composition and host cell internalization.

  16. Virtual nuclear envelope breakdown and its regulators in fission yeast meiosis

    Directory of Open Access Journals (Sweden)

    Haruhiko eAsakawa

    2016-02-01

    Full Text Available Ran, a small GTPase, is required for the spindle formation and nuclear envelope (NE formation. After NE breakdown (NEBD during mitosis in metazoan cells, the Ran-GTP gradient across the NE is lost and Ran-GTP becomes concentrated around chromatin, thus affecting the stability of microtubules and promoting the assembly of spindle microtubules and segregation of chromosomes. Mitosis in which chromosomes are segregated subsequent to NEBD is called open mitosis. In contrast, many fungi undergo a process termed closed mitosis in which chromosome segregation and spindle formation occur without NEBD. Although the fission yeast Schizosaccharomyces pombe undergoes a closed mitosis, it exhibits a short period during meiosis (anaphase of the second meiosis; called anaphase II when nuclear and cytoplasmic proteins are mixed in the presence of intact NE and nuclear pore complexes (NPC. This virtual nuclear envelope breakdown (vNEBD involves changes in the localization of RanGAP1, an activator of Ran-GTP hydrolysis. Recently, Nup132, a component of the structural core Nup107-160 subcomplex of the NPC, has been shown to be involved in the maintenance of the nuclear cytoplasmic barrier in yeast meiosis. In this review, we highlight the possible roles of RanGAP1 and Nup132 in vNEBD and discuss the biological significance of vNEBD in S. pombe meiosis.

  17. A CRISPR-Cas system enhances envelope integrity mediating antibiotic resistance and inflammasome evasion

    Science.gov (United States)

    Sampson, Timothy R.; Napier, Brooke A.; Schroeder, Max R.; Louwen, Rogier; Zhao, Jinshi; Chin, Chui-Yoke; Ratner, Hannah K.; Llewellyn, Anna C.; Jones, Crystal L.; Laroui, Hamed; Merlin, Didier; Zhou, Pei; Endtz, Hubert P.; Weiss, David S.

    2014-01-01

    Clustered, regularly interspaced, short palindromic repeats–CRISPR associated (CRISPR-Cas) systems defend bacteria against foreign nucleic acids, such as during bacteriophage infection and transformation, processes which cause envelope stress. It is unclear if these machineries enhance membrane integrity to combat this stress. Here, we show that the Cas9-dependent CRISPR-Cas system of the intracellular bacterial pathogen Francisella novicida is involved in enhancing envelope integrity through the regulation of a bacterial lipoprotein. This action ultimately provides increased resistance to numerous membrane stressors, including antibiotics. We further find that this previously unappreciated function of Cas9 is critical during infection, as it promotes evasion of the host innate immune absent in melanoma 2/apoptosis associated speck-like protein containing a CARD (AIM2/ASC) inflammasome. Interestingly, the attenuation of the cas9 mutant is complemented only in mice lacking both the AIM2/ASC inflammasome and the bacterial lipoprotein sensor Toll-like receptor 2, but not in single knockout mice, demonstrating that Cas9 is essential for evasion of both pathways. These data represent a paradigm shift in our understanding of the function of CRISPR-Cas systems as regulators of bacterial physiology and provide a framework with which to investigate the roles of these systems in myriad bacteria, including pathogens and commensals. PMID:25024199

  18. Solubilization of Envelopes of HVJ (Sendai virus) with Alkali-Emasol Treatment and Reassembly of Envelope Particles with Removal of the Detergent

    Science.gov (United States)

    Shimizu, Kazufumi; Hosaka, Yashuhiro; Shimizu, Yohko K.

    1972-01-01

    The envelopes of HVJ (Sendai virus) virions were solubilized with alkali-Emasol treatment. The solubilized envelope subunit(s) associated with hemagglutination-inhibiting antibody blocking, neuraminidase, and low hemagglutinating (HA) activities had a sedimentation coefficient of 8.8S. Envelope fragment-like structures were assembled from the solubilized subunits after Emasol was removed by gel filtration. These reassembled envelope particles with HA activity had cell-fusion activity as well as hemolytic activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the reassembled particles revealed that they mainly consisted of two kinds of polypeptides. Images PMID:4337169

  19. SOFIA/HAWC+ Polarization in the Envelope of IRC+10216

    Science.gov (United States)

    Andersson, B.-G.; Hoang, Thiem; Lopez-Rodriguez, Enrique; Vaillancourt, John; Sankrit, Ravi; Lazarian, Alex; HAWC+ Instrument Team

    2018-01-01

    Polarization is a potentially powerful, but underutilized, tool for understanding interstellar, circumstellar environments. To accurately interpret dust-induced polarization, in terms of magnetic fields and other environmental parameters, a quantitative understanding of the alignment of the dust grains is, however, required. Significant progress has been made recently in clarifying the physics of grain alignment, such that we now know that radiative processes is the main driver. One remaining open issue is the role of grain mineralogy on the alignment, specifically whether carbonaceous grains can be aligned. We have acquired SOFIA/HAWC+ polarimetry of the carbon rich envelope of the AGB star IRC+10216 to probe this issue. Strong, systematic far-infrared polarization is seen in the envelope. We will discuss these data, their interpretation and their implication on the physics of grain alignment and interstellar, and circumstellar, polarimetry.

  20. Interior thermal insulation systems for historical building envelopes

    Science.gov (United States)

    Jerman, Miloš; Solař, Miloš; Černý, Robert

    2017-11-01

    The design specifics of interior thermal insulation systems applied for historical building envelopes are described. The vapor-tight systems and systems based on capillary thermal insulation materials are taken into account as two basic options differing in building-physical considerations. The possibilities of hygrothermal analysis of renovated historical envelopes including laboratory methods, computer simulation techniques, and in-situ tests are discussed. It is concluded that the application of computational models for hygrothermal assessment of interior thermal insulation systems should always be performed with a particular care. On one hand, they present a very effective tool for both service life assessment and possible planning of subsequent reconstructions. On the other, the hygrothermal analysis of any historical building can involve quite a few potential uncertainties which may affect negatively the accuracy of obtained results.

  1. Time dependent wave envelope finite difference analysis of sound propagation

    Science.gov (United States)

    Baumeister, K. J.

    1984-01-01

    A transient finite difference wave envelope formulation is presented for sound propagation, without steady flow. Before the finite difference equations are formulated, the governing wave equation is first transformed to a form whose solution tends not to oscillate along the propagation direction. This transformation reduces the required number of grid points by an order of magnitude. Physically, the transformed pressure represents the amplitude of the conventional sound wave. The derivation for the wave envelope transient wave equation and appropriate boundary conditions are presented as well as the difference equations and stability requirements. To illustrate the method, example solutions are presented for sound propagation in a straight hard wall duct and in a two dimensional straight soft wall duct. The numerical results are in good agreement with exact analytical results.

  2. Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

    Science.gov (United States)

    Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

    2009-01-01

    Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

  3. Functional envelope of a non-autonomous discrete system

    Directory of Open Access Journals (Sweden)

    Barzanouni Ali

    2017-11-01

    Full Text Available Let (X, F = {fn}n =0∞ be a non-autonomous discrete system by a compact metric space X and continuous maps fn : X → X, n = 0, 1, ....We introduce functional envelope (S(X, G = {Gn}n =0∞, of (X, F = {fn}n =0∞, where S(X is the space of all continuous self maps of X and the map Gn : S(X → S(X is defined by Gn(ϕ = Fn ∘ ϕ, Fn = fn ∘ fn-1 ∘ . . . ∘ f1 ∘ f0. The paper mainly deals with the connection between the properties of a system and the properties of its functional envelope.

  4. Full-Envelope Launch Abort System Performance Analysis Methodology

    Science.gov (United States)

    Aubuchon, Vanessa V.

    2014-01-01

    The implementation of a new dispersion methodology is described, which dis-perses abort initiation altitude or time along with all other Launch Abort System (LAS) parameters during Monte Carlo simulations. In contrast, the standard methodology assumes that an abort initiation condition is held constant (e.g., aborts initiated at altitude for Mach 1, altitude for maximum dynamic pressure, etc.) while dispersing other LAS parameters. The standard method results in large gaps in performance information due to the discrete nature of initiation conditions, while the full-envelope dispersion method provides a significantly more comprehensive assessment of LAS abort performance for the full launch vehicle ascent flight envelope and identifies performance "pinch-points" that may occur at flight conditions outside of those contained in the discrete set. The new method has significantly increased the fidelity of LAS abort simulations and confidence in the results.

  5. Spectropolarimetry of stripped-envelope supernovae: observations and modelling

    Science.gov (United States)

    Tanaka, Masaomi

    2017-09-01

    Spectropolarimetry is one of the most powerful methods to study the multi-dimensional geometry of supernovae (SNe). We present a brief summary of the spectropolarimetric observations of stripped-envelope core-collapse SNe. Observations indicate that stripped-envelope SNe generally have a non-axisymmetric ion distribution in the ejecta. Three-dimensional clumpy geometry nicely explains the observed properties. A typical size of the clumps deduced from observations is relatively large: 25% of the photosphere. Such a large-scale clumpy structure is similar to that observed in Cassiopeia A, and suggests that large-scale convection or standing accretion shock instability takes place at the onset of the explosion. This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'.

  6. A Review of Ranking Models in Data Envelopment Analysis

    OpenAIRE

    Hosseinzadeh Lotfi, F.; Jahanshahloo, G.R.; M. Khodabakhshi; Rostamy-Malkhlifeh, M.; Moghaddas, Z.; Vaez-Ghasemi, M.

    2013-01-01

    In the course of improving various abilities of data envelopment analysis (DEA) models, many investigations have been carried out for ranking decision-making units (DMUs). This is an important issue both in theory and practice. There exist a variety of papers which apply different ranking methods to a real data set. Here the ranking methods are divided into seven groups. As each of the existing methods can be viewed from different aspects, it is possible that somewhat these groups have an ove...

  7. Case Study of Envelope Sealing in Existing Multiunit Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, Jordan [ARIES Collaborative, New York, NY (United States); Conlin, Francis [ARIES Collaborative, New York, NY (United States); Podorson, David [ARIES Collaborative, New York, NY (United States)

    2012-10-01

    This report describes envelope air sealing that was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Specifications and a pictorial guide were developed for contractors performing the work.

  8. A Benchmark Analysis of Italian Seaports Using Data Envelopment Analysis

    OpenAIRE

    Carlos Pestana Barros

    2006-01-01

    This paper uses data envelopment analysis to evaluate the performance of Italian seaports from 2002 to 2003, combining operational and financial variables. The paper evaluates how close the Italian seaports are to the frontier of best practices. Moreover, the paper also tests for the role played by size, containerisation and labour in the efficiency of the seaports analysed. The general conclusion is that the Italians seaports examined display relatively high efficiency. However, there are al...

  9. A Comparison of PSD Enveloping Methods for Nonstationary Vibration

    Science.gov (United States)

    Irvine, Tom

    2015-01-01

    There is a need to derive a power spectral density (PSD) envelope for nonstationary acceleration time histories, including launch vehicle data, so that components can be designed and tested accordingly. This paper presents the results of the three methods for an actual flight accelerometer record. Guidelines are given for the application of each method to nonstationary data. The method can be extended to other scenarios, including transportation vibration.

  10. The envelope of ballistic trajectories and elliptic orbits

    Science.gov (United States)

    Butikov, Eugene I.

    2015-11-01

    Simple geometric derivations are given for the shape of the "safety domain" boundary for the family of Keplerian orbits of equal energy in a central gravitational field and for projectile trajectories in a uniform field. Examples of practical uses of the envelope of the family of orbits are discussed and illustrated by computer simulations. This material is appropriate for physics teachers and undergraduate students studying classical mechanics and orbital motions.

  11. Planetary Gearbox Fault Diagnosis Using Envelope Manifold Demodulation

    OpenAIRE

    Weigang Wen; Gao, Robert X.; Weidong Cheng

    2016-01-01

    The important issue in planetary gear fault diagnosis is to extract the dependable fault characteristics from the noisy vibration signal of planetary gearbox. To address this critical problem, an envelope manifold demodulation method is proposed for planetary gear fault detection in the paper. This method combines complex wavelet, manifold learning, and frequency spectrogram to implement planetary gear fault characteristic extraction. The vibration signal of planetary gear is demodulated by w...

  12. Analysis of quadrature detectors using complex envelope notation

    Science.gov (United States)

    Roome, S. J.

    1989-04-01

    Quadrature detection is a common technique for demodulating radio and microwave signals in which the signal is demodulated to form two orthogonal components. Complex envelope notation is a compact method of representing the modulation of a real signal in complex form. The relationship between these two concepts is discussed, and there follows an analysis of quadrature demodulation, including the effects of gain mismatch, phase error, local oscillator breakthrough, and dc offsets.

  13. Nonlinear envelope equation for broadband optical pulses in quadratic media

    CERN Document Server

    Conforti, Matteo; De Angelis, Costantino

    2010-01-01

    We derive a nonlinear envelope equation to describe the propagation of broadband optical pulses in second order nonlinear materials. The equation is first order in the propagation coordinate and is valid for arbitrarily wide pulse bandwidth. Our approach goes beyond the usual coupled wave description of $\\chi^{(2)}$ phenomena and provides an accurate modelling of the evolution of ultra-broadband pulses also when the separation into different coupled frequency components is not possible or not profitable.

  14. Comparative Analysis of the Glycosylation Profiles of Membrane-Anchored HIV-1 Envelope Glycoprotein Trimers and Soluble gp140

    Science.gov (United States)

    Go, Eden P.; Herschhorn, Alon; Gu, Christopher; Castillo-Menendez, Luis; Zhang, Shijian; Mao, Youdong; Chen, Haiyan; Ding, Haitao; Wakefield, John K.; Hua, David; Liao, Hua-Xin; Kappes, John C.; Sodroski, Joseph

    2015-01-01

    ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer, which consists of the gp120 and gp41 subunits, is the focus of multiple strategies for vaccine development. Extensive Env glycosylation provides HIV-1 with protection from the immune system, yet the glycans are also essential components of binding epitopes for numerous broadly neutralizing antibodies. Recent studies have shown that when Env is isolated from virions, its glycosylation profile differs significantly from that of soluble forms of Env (gp120 or gp140) predominantly used in vaccine discovery research. Here we show that exogenous membrane-anchored Envs, which can be produced in large quantities in mammalian cells, also display a virion-like glycan profile, where the glycoprotein is extensively decorated with high-mannose glycans. Additionally, because we characterized the glycosylation with a high-fidelity profiling method, glycopeptide analysis, an unprecedented level of molecular detail regarding membrane Env glycosylation and its heterogeneity is presented. Each glycosylation site was characterized individually, with about 500 glycoforms characterized per Env protein. While many of the sites contain exclusively high-mannose glycans, others retain complex glycans, resulting in a glycan profile that cannot currently be mimicked on soluble gp120 or gp140 preparations. These site-level studies are important for understanding antibody-glycan interactions on native Env trimers. Additionally, we report a newly observed O-linked glycosylation site, T606, and we show that the full O-linked glycosylation profile of membrane-associated Env is similar to that of soluble gp140. These findings provide new insight into Env glycosylation and clarify key molecular-level differences between membrane-anchored Env and soluble gp140. IMPORTANCE A vaccine that protects against human immunodeficiency virus type 1 (HIV-1) infection should elicit antibodies that bind to the surface

  15. ORF7 of Varicella-Zoster Virus Is Required for Viral Cytoplasmic Envelopment in Differentiated Neuronal Cells.

    Science.gov (United States)

    Jiang, Hai-Fei; Wang, Wei; Jiang, Xuan; Zeng, Wen-Bo; Shen, Zhang-Zhou; Song, Yi-Ge; Yang, Hong; Liu, Xi-Juan; Dong, Xiao; Zhou, Jing; Sun, Jin-Yan; Yu, Fei-Long; Guo, Lin; Cheng, Tong; Rayner, Simon; Zhao, Fei; Zhu, Hua; Luo, Min-Hua

    2017-06-15

    Although a varicella-zoster virus (VZV) vaccine has been used for many years, the neuropathy caused by VZV infection is still a major health concern. Open reading frame 7 (ORF7) of VZV has been recognized as a neurotropic gene in vivo , but its neurovirulent role remains unclear. In the present study, we investigated the effect of ORF7 deletion on VZV replication cycle at virus entry, genome replication, gene expression, capsid assembly and cytoplasmic envelopment, and transcellular transmission in differentiated neural progenitor cells (dNPCs) and neuroblastoma SH-SY5Y (dSY5Y) cells. Our results demonstrate that the ORF7 protein is a component of the tegument layer of VZV virions. Deleting ORF7 did not affect viral entry, viral genome replication, or the expression of typical viral genes but clearly impacted cytoplasmic envelopment of VZV capsids, resulting in a dramatic increase of envelope-defective particles and a decrease in intact virions. The defect was more severe in differentiated neuronal cells of dNPCs and dSY5Y. ORF7 deletion also impaired transmission of ORF7-deficient virus among the neuronal cells. These results indicate that ORF7 is required for cytoplasmic envelopment of VZV capsids, virus transmission among neuronal cells, and probably the neuropathy induced by VZV infection. IMPORTANCE The neurological damage caused by varicella-zoster virus (VZV) reactivation is commonly manifested as clinical problems. Thus, identifying viral neurovirulent genes and characterizing their functions are important for relieving VZV related neurological complications. ORF7 has been previously identified as a potential neurotropic gene, but its involvement in VZV replication is unclear. In this study, we found that ORF7 is required for VZV cytoplasmic envelopment in differentiated neuronal cells, and the envelopment deficiency caused by ORF7 deletion results in poor dissemination of VZV among neuronal cells. These findings imply that ORF7 plays a role in neuropathy

  16. The Nonlinear Analytical Envelope Equation in quadratic nonlinear crystals

    CERN Document Server

    Bache, Morten

    2016-01-01

    We here derive the so-called Nonlinear Analytical Envelope Equation (NAEE) inspired by the work of Conforti et al. [M. Conforti, A. Marini, T. X. Tran, D. Faccio, and F. Biancalana, "Interaction between optical fields and their conjugates in nonlinear media," Opt. Express 21, 31239-31252 (2013)], whose notation we follow. We present a complete model that includes $\\chi^{(2)}$ terms [M. Conforti, F. Baronio, and C. De Angelis, "Nonlinear envelope equation for broadband optical pulses in quadratic media," Phys. Rev. A 81, 053841 (2010)], $\\chi^{(3)}$ terms, and then extend the model to delayed Raman effects in the $\\chi^{(3)}$ term. We therefore get a complete model for ultrafast pulse propagation in quadratic nonlinear crystals similar to the Nonlinear Wave Equation in Frequency domain [H. Guo, X. Zeng, B. Zhou, and M. Bache, "Nonlinear wave equation in frequency domain: accurate modeling of ultrafast interaction in anisotropic nonlinear media," J. Opt. Soc. Am. B 30, 494-504 (2013)], but where the envelope is...

  17. Experiences when employing different alternatives for envelope upgrading

    Directory of Open Access Journals (Sweden)

    Peru Elguezabal Esnarrizaga

    2015-06-01

    Full Text Available The challenges of achieving the 2020 goals in terms of energy savings and improving efficiency are guiding numerous research initiatives looking for more insulated envelopes, dealing with thermal performance of insulation materials and envelope systems. Nevertheless, the envelope integrates within the building and this improvement on the insulation performance has to be properly adopted, taking into account the interrelation of main elements composing the overall system (facade, frame, slabs, openings, partitions etc., as well as side effects originated not only for new erected buildings, but specifically in renovation and retrofitting works. This paper describes real experiences when considering various options for upgrading the facade through the increase of the insulation capacity, starting from external overcladding prefabricated panels and ventilated facades, advancing to more sustainable low carbon systems and ending with even more highly insulated solutions employing aerogels. Lessons from these cases, where energy and hygrothermal assessments have being carried out, demonstrate the influence of the design and construction phases and the relevance of disregarded effects such as minor thermal bridges, uncontrolled craftsmanship on site, and moisture transfer for the different technologies considered. Finally, possible alternatives are provided to overcome some of the detected difficulties, such as combination with non-metallic structural components and building membranes, and being prepared for future challenges and new developments when these isolative elements are combined with other technologies, as for example, renewable energy harvesting devices.  

  18. Solar active envelope module with an adjustable transmittance/absorptance

    Directory of Open Access Journals (Sweden)

    C. Villasante Villasante

    2015-06-01

    Full Text Available A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three glazed chambers with advanced coatings and frames to assure a minimum thermal transmittance while allowing transparency. A fluid containing heat-absorbing nanoparticles flows inside the central chamber and is heated up due to the impinging solar energy. Unlike other systems proposed in the past, which included transparency control systems based on complex filters and chemical processes, the absorption of the module is controlled by the variation of the thickness of the central chamber with a mechanical device. That is, varying the thickness of the central chamber, it allows controlling the absorptance of the whole system and, as a result, indoor day-lighting and thermal loads. Therefore, a new system is proposed that enables to:  

  19. Biomimetic Architecture in Building Envelope Maintenance (A Literature

    Directory of Open Access Journals (Sweden)

    Agus Salim N.A.

    2014-01-01

    Full Text Available The study of biomimetic architecture on building envelope is the main structure of this research. The concept is believed more sustainable and efficient for energy saving, operating cost consumption, waste recycle and design renewal in the future. The inspiration from the nature developed the intention on this study to explore on what and how this concept to overcome the problems through design. Biomimicry does catch the attention of human to study more on the system and function of its nature course. The designers are not exception influenced by this concept when the form, shape, texture and colour inspired them in their design. The domination of building form will affect the building envelope as the skin of the structure. A clear impact on building failure is begun with building envelope appearance without a proper maintenance. The faults in building design place a heavy burden on the building for the rest of its operational life and there is no compensation for it. In such situations, the responsibility falls on the shoulders of the designer.

  20. Dynamics of jets during the common-envelope phase

    Science.gov (United States)

    Moreno Méndez, Enrique; López-Cámara, Diego; De Colle, Fabio

    2017-09-01

    Common envelope (CE) is an important phase in the evolution of many binary systems. Giant star/compact object interaction in binaries plays an important role in high-energy phenomena as well as in the evolution of their environment. Material accreted on to the compact object may form a disc and power a jet. We study analytically and through numerical simulations the interaction between the jet and the CE. We determine the conditions under which accreting material quenches the jet or allows it to propagate successfully, in which case even the envelope may be ejected. Close to the stellar core of the companion, the compact object accretes at a larger rate. A jet launched from this region needs a larger accretion-to-ejection efficiency to successfully propagate through the CE compared to a jet launched far from the stellar core, and is strongly deflected by the orbital motion. The energy deposited by the jet may be larger than the binding energy of the envelope. The jet can, thus, play a fundamental role in the CE evolution. We find that the energy dissipation of the jet into the CE may stop accretion on to the disc. We expect the jet to be intermittent, unless the energy deposited is large enough to lead to the unbinding of the outer layers of the CE. Given that the energy and duration of the jet are similar to those of ultralong gamma-ray bursts, we suggest this as a new channel to produce these events.