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 ...

Construction and characterization of a glycoprotein E deletion mutant of bovine herpesvirus type 1.2 strain isolated in Brazil

NARCIS (Netherlands)

Franco, A.C.; Rijsewijk, F.A.M.; Flores, E.F.; Weiblen, R.; Roehe, P.M.

2002-01-01

This paper describes the construction and characterization of a Brazilian strain of bovine herpesvirus type 1.2a (BoHV-1.2a) with a deletion of the glycoprotein E (gE) gene. The deletion was introduced by co-transfection of a deletion fragment containing the 5´and 3´gE flanking regions and genomic

Prediction and identification of potential immunodominant epitopes in glycoproteins B, C, E, G, and I of herpes simplex virus type 2.

Science.gov (United States)

Pan, Mingjie; Wang, Xingsheng; Liao, Jianmin; Yin, Dengke; Li, Suqin; Pan, Ying; Wang, Yao; Xie, Guangyan; Zhang, Shumin; Li, Yuexi

2012-01-01

Twenty B candidate epitopes of glycoproteins B (gB2), C (gC2), E (gE2), G (gG2), and I (gI2) of herpes simplex virus type 2 (HSV-2) were predicted using DNAstar, Biosun, and Antheprot methods combined with the polynomial method. Subsequently, the biological functions of the peptides were tested via experiments in vitro. Among the 20 epitope peptides, 17 could react with the antisera to the corresponding parent proteins in the EIA tests. In particular, five peptides, namely, gB2(466-473) (EQDRKPRN), gC2(216-223) (GRTDRPSA), gE2(483-491) (DPPERPDSP), gG2(572-579) (EPPDDDDS), and gI2(286-295) (CRRRYRRPRG) had strong reaction with the antisera. All conjugates of the five peptides with the carrier protein BSA could stimulate mice into producing antibodies. The antisera to these peptides reacted strongly with the corresponding parent glycoproteins during the Western Blot tests, and the peptides reacted strongly with the antibodies against the parent glycoproteins during the EIA tests. The antisera against the five peptides could neutralize HSV-2 infection in vitro, which has not been reported until now. These results suggest that the immunodominant epitopes screened using software algorithms may be used for virus diagnosis and vaccine design against HSV-2.

Prediction and Identification of Potential Immunodominant Epitopes in Glycoproteins B, C, E, G, and I of Herpes Simplex Virus Type 2

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Mingjie Pan

2012-01-01

Full Text Available Twenty B candidate epitopes of glycoproteins B (gB2, C (gC2, E (gE2, G (gG2, and I (gI2 of herpes simplex virus type 2 (HSV-2 were predicted using DNAstar, Biosun, and Antheprot methods combined with the polynomial method. Subsequently, the biological functions of the peptides were tested via experiments in vitro. Among the 20 epitope peptides, 17 could react with the antisera to the corresponding parent proteins in the EIA tests. In particular, five peptides, namely, gB2466–473 (EQDRKPRN, gC2216–223 (GRTDRPSA, gE2483–491 (DPPERPDSP, gG2572–579 (EPPDDDDS, and gI2286-295 (CRRRYRRPRG had strong reaction with the antisera. All conjugates of the five peptides with the carrier protein BSA could stimulate mice into producing antibodies. The antisera to these peptides reacted strongly with the corresponding parent glycoproteins during the Western Blot tests, and the peptides reacted strongly with the antibodies against the parent glycoproteins during the EIA tests. The antisera against the five peptides could neutralize HSV-2 infection in vitro, which has not been reported until now. These results suggest that the immunodominant epitopes screened using software algorithms may be used for virus diagnosis and vaccine design against HSV-2.

Functionality of Chimeric E2 Glycoproteins of BVDV and CSFV in Virus Replication

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H.G.P. van Gennip

2008-01-01

Full Text Available An intriguing difference between the E2 glycoprotein of CSFV and the other groups of pestiviruses (nonCSFV is a lack of two cysteine residues on positions cysteine 751 and 798. Other groups of pestivirus are not restricted to one species as swine, whereas CSFV is restricted to swine and wild boar. We constructed chimeric CSFV/BVDV E2 genes based on a 2D model of E2 proposed by van Rijn et al. (van Rijn et al. 1994, J Virol 68, 3934–42 and confirmed their expression by immunostaining of plasmid-transfected SK6 cells. No equivalents for the antigenic units B/C and A were found on E2 of BVDVII. This indicates major structural differences in E2. However, the immunodominant BVDVII domain A, containing epitopes with essential amino acids between position 760–764, showed to be dependent on the presence of the region defined by amino acids 684 to 796. As for the A domain of CSFV, the BVDVII A-like domain seemed to function as a separate unit. These combined domains in E2 proved to be the only combination which was functional in viral background of CSFV C-strain. The fitness of this virus (vfl c36BVDVII 684–796 seemed to be reduced compared to vfl c9 (with the complete antigenic region of BVDVII.

Functionality of Chimeric E2 Glycoproteins of BVDV and CSFV in Virus Replication

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H.G.P. Van Gennip

2008-01-01

Full Text Available An intriguing difference between the E2 glycoprotein of CSFV and the other groups of pestiviruses (nonCSFV is a lack of two cysteine residues on positions cysteine 751 and 798. Other groups of pestivirus are not restricted to one species as swine, whereas CSFV is restricted to swine and wild boar. We constructed chimeric CSFV/BVDV E2 genes based on a 2D model of E2 proposed by van Rijn et al. (van Rijn et al. 1994, J Virol 68, 3934–42 and confirmed their expression by immunostaining of plasmid-transfected SK6 cells. No equivalents for the antigenic units B/C and A were found on E2 of BVDVII. This indicates major structural differences in E2. However, the immunodominant BVDVII domain A, containing epitopes with essential amino acids between position 760–764, showed to be dependent on the presence of the region defined by amino acids 684 to 796. As for the A domain of CSFV, the BVDVII A-like domain seemed to function as a separate unit. These combined domains in E2 proved to be the only combination which was functional in viral background of CSFV C-strain. The fitness of this virus (vflc36 BVDVII 684–796 seemed to be reduced compared to vflc9 (with the complete antigenic region of BVDVII.

Mutations in the Schmallenberg Virus Gc Glycoprotein Facilitate Cellular Protein Synthesis Shutoff and Restore Pathogenicity of NSs Deletion Mutants in Mice.

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Varela, Mariana; Pinto, Rute Maria; Caporale, Marco; Piras, Ilaria M; Taggart, Aislynn; Seehusen, Frauke; Hahn, Kerstin; Janowicz, Anna; de Souza, William Marciel; Baumgärtner, Wolfgang; Shi, Xiaohong; Palmarini, Massimo

2016-06-01

Serial passage of viruses in cell culture has been traditionally used to attenuate virulence and identify determinants of viral pathogenesis. In a previous study, we found that a strain of Schmallenberg virus (SBV) serially passaged in tissue culture (termed SBVp32) unexpectedly displayed increased pathogenicity in suckling mice compared to wild-type SBV. In this study, we mapped the determinants of SBVp32 virulence to the viral genome M segment. SBVp32 virulence is associated with the capacity of this virus to reach high titers in the brains of experimentally infected suckling mice. We also found that the Gc glycoprotein, encoded by the M segment of SBVp32, facilitates host cell protein shutoff in vitro Interestingly, while the M segment of SBVp32 is a virulence factor, we found that the S segment of the same virus confers by itself an attenuated phenotype to wild-type SBV, as it has lost the ability to block the innate immune system of the host. Single mutations present in the Gc glycoprotein of SBVp32 are sufficient to compensate for both the attenuated phenotype of the SBVp32 S segment and the attenuated phenotype of NSs deletion mutants. Our data also indicate that the SBVp32 M segment does not act as an interferon (IFN) antagonist. Therefore, SBV mutants can retain pathogenicity even when they are unable to fully control the production of IFN by infected cells. Overall, this study suggests that the viral glycoprotein of orthobunyaviruses can compensate, at least in part, for the function of NSs. In addition, we also provide evidence that the induction of total cellular protein shutoff by SBV is determined by multiple viral proteins, while the ability to control the production of IFN maps to the NSs protein. The identification of viral determinants of pathogenesis is key to the development of prophylactic and intervention measures. In this study, we found that the bunyavirus Gc glycoprotein is a virulence factor. Importantly, we show that mutations in the Gc

Pyrosequencing-Based Assays for Rapid Detection of HER2 and HER3 Mutations in Clinical Samples Uncover an E332E Mutation Affecting HER3 in Retroperitoneal Leiomyosarcoma

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Paula González-Alonso

2015-08-01

Full Text Available Mutations in Human Epidermal Growth Factor Receptors (HER are associated with poor prognosis of several types of solid tumors. Although HER-mutation detection methods are currently available, such as Next-Generation Sequencing (NGS, alternative pyrosequencing allow the rapid characterization of specific mutations. We developed specific PCR-based pyrosequencing assays for identification of most prevalent HER2 and HER3 mutations, including S310F/Y, R678Q, L755M/P/S/W, V777A/L/M, 774-776 insertion, and V842I mutations in HER2, as well as M91I, V104M/L, D297N/V/Y, and E332E/K mutations in HER3. We tested 85 Formalin Fixed and Paraffin Embbeded (FFPE samples and we detected three HER2-V842I mutations in colorectal carcinoma (CRC, ovarian carcinoma, and pancreatic carcinoma patients, respectively, and a HER2-L755M mutation in a CRC specimen. We also determined the presence of a HER3-E332K mutation in an urothelial carcinoma sample, and two HER3-D297Y mutations, in both gastric adenocarcinoma and CRC specimens. The D297Y mutation was previously detected in breast and gastric tumors, but not in CRC. Moreover, we found a not-previously-described HER3-E332E synonymous mutation in a retroperitoneal leiomyosarcoma patient. The pyrosequencing assays presented here allow the detection and characterization of specific HER2 and HER3 mutations. These pyrosequencing assays might be implemented in routine diagnosis for molecular characterization of HER2/HER3 receptors as an alternative to complex NGS approaches.

Expression, purification and crystallization of the ectodomain of the envelope glycoprotein E2 from Bovine viral diarrhoea virus

International Nuclear Information System (INIS)

Iourin, Oleg; Harlos, Karl; El Omari, Kamel; Lu, Weixian; Kadlec, Jan; Iqbal, Munir; Meier, Christoph; Palmer, Andrew; Jones, Ian; Thomas, Carole; Brownlie, Joe; Grimes, Jonathan M.; Stuart, David I.

2012-01-01

The cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the ectodomain of BVDV E2 are described. Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen which is closely related to Hepatitis C virus. Of the structural proteins, the envelope glycoprotein E2 of BVDV is the major antigen which induces neutralizing antibodies; thus, BVDV E2 is considered as an ideal target for use in subunit vaccines. Here, the expression, purification of wild-type and mutant forms of the ectodomain of BVDV E2 and subsequent crystallization and data collection of two crystal forms grown at low and neutral pH are reported. Native and multiple-wavelength anomalous dispersion (MAD) data sets have been collected and structure determination is in progress

Alteration of a second putative fusion peptide of structural glycoprotein E2 of Classical Swine Fever Virus alters virus replication and virulence in swine

Science.gov (United States)

E2, the major envelope glycoprotein of Classical Swine Fever Virus (CSFV), is involved in several critical virus functions including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on Wimley-White interfacial hydrophobicity dis...

Analysing the Structural Effect of Point Mutations of Cytotoxic Necrotizing Factor 1 (CNF1 on Lu/BCAM Adhesion Glycoprotein Association

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Alexandre G. de Brevern

2018-03-01

Full Text Available Cytotoxic Necrotizing Factor 1 (CNF1 was identified in 1983 as a protein toxin produced by certain pathogenic strains of Escherichia coli. Since then, numerous studies have investigated its particularities. For instance, it is associated with the single chain AB-toxin family, and can be divided into different functional and structural domains, e.g., catalytic and transmembrane domain and interaction sites. A few years ago, the identification of the Lutheran (Lu adhesion glycoprotein/basal cell adhesion molecule (BCAM as a cellular receptor for CNF1 provided new insights into the adhesion process of CNF1. Very recently, the Ig-like domain 2 of Lu/BCAM was confirmed as the main interaction site using protein-protein interaction and competition studies with various different mutants. Here, I present in silico approaches that precisely explain the impact of these mutations, leading to a better explanation of these experimental studies. These results can be used in the development of future antitoxin strategies.

Glycoprotein on cell surfaces

International Nuclear Information System (INIS)

Muramatsu, T.

1975-01-01

There are conjugated polysaccharides in cell membranes and outside of animal cells, and they play important role in the control of cell behavior. In this paper, the studies on the glycoprotein on cell surfaces are reported. It was found that the glycoprotein on cell surfaces have both N-glycoside type and O-glycoside type saccharic chains. Therefore it can be concluded that the basic structure of the saccharic chains in the glycoprotein on cell surfaces is similar to that of blood serum and body fluid. The main glycoprotein in the membranes of red blood corpuscles has been studied most in detail, and it also has both types of saccharic chains. The glycoprotein in liver cell membranes was found to have only the saccharic chains of acid type and to be in different pattern from that in endoplasmic reticula and nuclear membranes, which also has the saccharic chains of neutral type. The structure of the saccharic chains of H-2 antigen, i.e. the peculiar glycoprotein on the surfaces of lymph system cells, has been studied, and it is similar to the saccharic chains of glycoprotein in blood serum. The saccharic chain structures of H-2 antigen and TL antigen are different. TL, H-2 (D), Lna and H-2 (K) are the glycoprotein on cell surfaces, and are independent molecules. The analysis of the saccharic chain patterns on cell surfaces was carried out, and it was shown that the acid type saccharic chains were similar to those of ordinary glycoprotein, because the enzyme of pneumococci hydrolyzed most of the acid type saccharic chains. The change of the saccharic chain patterns of glycoprotein on cell surfaces owing to canceration and multiplication is complex matter. (Kako, I.)

Monoclonal Antibodies Directed toward the Hepatitis C Virus Glycoprotein E2 Detect Antigenic Differences Modulated by the N-Terminal Hypervariable Region 1 (HVR1), HVR2, and Intergenotypic Variable Region.

Science.gov (United States)

Alhammad, Yousef; Gu, Jun; Boo, Irene; Harrison, David; McCaffrey, Kathleen; Vietheer, Patricia T; Edwards, Stirling; Quinn, Charles; Coulibaly, Fásseli; Poumbourios, Pantelis; Drummer, Heidi E

2015-12-01

Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 form a heterodimer and mediate receptor interactions and viral fusion. Both E1 and E2 are targets of the neutralizing antibody (NAb) response and are candidates for the production of vaccines that generate humoral immunity. Previous studies demonstrated that N-terminal hypervariable region 1 (HVR1) can modulate the neutralization potential of monoclonal antibodies (MAbs), but no information is available on the influence of HVR2 or the intergenotypic variable region (igVR) on antigenicity. In this study, we examined how the variable regions influence the antigenicity of the receptor binding domain of E2 spanning HCV polyprotein residues 384 to 661 (E2661) using a panel of MAbs raised against E2661 and E2661 lacking HVR1, HVR2, and the igVR (Δ123) and well-characterized MAbs isolated from infected humans. We show for a subset of both neutralizing and nonneutralizing MAbs that all three variable regions decrease the ability of MAbs to bind E2661 and reduce the ability of MAbs to inhibit E2-CD81 interactions. In addition, we describe a new MAb directed toward the region spanning residues 411 to 428 of E2 (MAb24) that demonstrates broad neutralization against all 7 genotypes of HCV. The ability of MAb24 to inhibit E2-CD81 interactions is strongly influenced by the three variable regions. Our data suggest that HVR1, HVR2, and the igVR modulate exposure of epitopes on the core domain of E2 and their ability to prevent E2-CD81 interactions. These studies suggest that the function of HVR2 and the igVR is to modulate antibody recognition of glycoprotein E2 and may contribute to immune evasion. This study reveals conformational and antigenic differences between the Δ123 and intact E2661 glycoproteins and provides new structural and functional data about the three variable regions and their role in occluding neutralizing and nonneutralizing epitopes on the E2 core domain. The variable regions may therefore function to

A novel NR2E3 gene mutation in autosomal recessive retinitis pigmentosa with cystic maculopathy

OpenAIRE

Mahajan, D.; Votruba, Marcela

2017-01-01

NR2E3 is a gene that encodes for photoreceptor cell specific nuclear receptor, which is involved in cone proliferation. The splice site mutation 119-2A>C in NR2E3 (15q23) has been previously reported to underlie recessive enhanced cone S sensitivity syndrome, clumped pigmentary retinal degeneration, Goldman-Favre syndrome and also autosomal dominant and autosomal recessive retinitis pigmentosa (RP). However, the mutation c 571 + 2 T > C in NR2E3 has not been previously reported with retinal d...

Marburg Virus Glycoprotein GP2: pH-Dependent Stability of the Ectodomain α-Helical Bundle†

Science.gov (United States)

Harrison, Joseph S.; Koellhoffer, Jayne F.; Chandran, Kartik; Lai, Jonathan R.

2012-01-01

Marburg virus (MARV) and Ebola virus (EBOV) constitute the family Filoviridae of enveloped viruses (filoviruses) that cause severe hemorrhagic fever. Infection by MARV is required for fusion between the host cell and viral membranes, a process that is mediated by the two subunits of the envelope glycoprotein GP1 (surface subunit) and GP2 (transmembrane subunit). Upon viral attachment and uptake, it is believed that the MARV viral fusion machinery is triggered by host factors and environmental conditions found in the endosome. Next, conformational rearrangements in the GP2 ectodomain result in the formation of a highly stable six-helix bundle; this refolding event provides the energetic driving force for membrane fusion. Both GP1 and GP2 from EBOV have been extensively studied, but there is little information available for the MARV glycoproteins. Here we have expressed two variants of the MARV GP2 ectodomain in Escherichia coli and analyzed their biophysical properties. Circular dichroism indicates that the MARV GP2 ectodomain adopts an α-helical conformation, and one variant sediments as a trimer by equilibrium analytical ultracentrifugation. Denaturation studies indicate the α-helical structure is highly stable at pH 5.3 (unfolding energy, ΔGunf H2O, of 33.4 ± 2.5 kcal/mol and melting temperature, Tm, of 75.3 ± 2.1 °C for one variant). Furthermore, we found the α-helical stability to be strongly dependent on pH with higher stability under lower pH conditions (Tm values ranging from ~92 °C at pH 4.0 to ~38 °C at pH 8.0). Mutational analysis suggests two glutamic acid residues (E579 and E580) are partially responsible for this pH-dependent behavior. Based on these results, we hypothesize that pH-dependent folding stability of the MARV GP2 ectodomain provides a mechanism to control conformational preferences such that the six-helix bundle ‘post-fusion’ state is preferred under conditions of appropriately matured endosomes. PMID:22369502

Development and evaluation of a replicon particle vaccine expressing the E2 glycoprotein of bovine viral diarrhea virus (BVDV in cattle

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Loy John Dustin

2013-01-01

Full Text Available Abstract Background Bovine viral diarrhea virus is one of the most significant and costly viral pathogens of cattle worldwide. Alphavirus-derived replicon particles have been shown to be safe and highly effective vaccine vectors against a variety of human and veterinary pathogens. Replicon particles are non-propagating, DIVA compatible, and can induce both humoral and cell mediated immune responses. This is the first experiment to demonstrate that Alphavirus-based replicon particles can be utilized in a standard prime/boost vaccination strategy in calves against a commercially significant bovine pathogen. Findings Replicon particles that express bovine viral diarrhea virus sub-genotype 1b E2 glycoprotein were generated and expression was confirmed in vitro using polyclonal and monoclonal antibodies specific to E2. Vaccine made from particles was generated in Vero cells and administered to BVDV free calves in a prime/boost regimen at two dosage levels. Vaccination resulted in neutralizing antibody titers that cross-neutralized both type 1 and type 2 BVD genotypes following booster vaccination. Additionally, high dose vaccine administration demonstrated some protection from clinical disease and significantly reduced the degree of leukopenia caused by viral infection. Conclusions Replicon particle vaccines administered in a prime/boost regimen expressing BVDV E2 glycoprotein can induce cross-neutralizing titers, reduce leukopenia post challenge, and mitigate clinical disease in calves. This strategy holds promise for a safe and effective vaccine to BVDV.

Krüppel-like factor 1 mutations and expression of hemoglobins F and A2 in homozygous hemoglobin E syndrome.

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Tepakhan, Wanicha; Yamsri, Supawadee; Fucharoen, Goonnapa; Sanchaisuriya, Kanokwan; Fucharoen, Supan

2015-07-01

The basis for variability of hemoglobin (Hb) F in homozygous Hb E disease is not well understood. We have examined multiple mutations of the Krüppel-like factor 1 (KLF1) gene; an erythroid specific transcription factor and determined their associations with Hbs F and A2 expression in homozygous Hb E. Four KLF1 mutations including G176AfsX179, T334R, R238H, and -154 (C-T) were screened using specific PCR assays on 461 subjects with homozygous Hb E and 100 normal controls. None of these four mutations were observed in 100 normal controls. Among 461 subjects with homozygous Hb E, 306 had high (≥5 %) and 155 had low (<5 %) Hb F. DNA analysis identified the KLF1 mutations in 35 cases of the former group with high Hb F, including the G176AfsX179 mutation (17/306 = 5.6 %), T334R mutation (9/306 = 2.9 %), -154 (C-T) mutation (7/306 = 2.3 %), and R328H mutation (2/306 = 0.7 %). Only two subjects in the latter group with low Hb F carried the G176AfsX179 and -154 (C-T) mutations. Significant higher Hb A2 level was observed in those of homozygous Hb E with the G176AfsX179 mutation as compared to those without KLF1 mutations. These results indicate that KLF1 is among the genetic factors associated with increased Hbs F and A2, and in combination with other factors could explain the variabilities of these Hb expression in Hb E syndrome.

Mutational analysis of the hepatitis C virus E1 glycoprotein in retroviral pseudoparticles and cell-culture-derived H77/JFH1 chimeric infectious virus particles

DEFF Research Database (Denmark)

Russell, R S; Kawaguchi, K; Meunier, J-C

2009-01-01

Cell entry by enveloped viruses is mediated by viral glycoproteins, and generally involves a short hydrophobic peptide (fusion peptide) that inserts into the cellular membrane. An internal hydrophobic domain within E1 (aa262-290) of hepatitis C virus (HCV) may function as a fusion peptide. Retrov...

A rare male patient with classic Rett syndrome caused by MeCP2_e1 mutation.

Science.gov (United States)

Tokaji, Narumi; Ito, Hiromichi; Kohmoto, Tomohiro; Naruto, Takuya; Takahashi, Rizu; Goji, Aya; Mori, Tatsuo; Toda, Yoshihiro; Saito, Masako; Tange, Shoichiro; Masuda, Kiyoshi; Kagami, Shoji; Imoto, Issei

2018-03-01

Rett syndrome (RTT) is a severe neurodevelopmental disorder typically affecting females. It is mainly caused by loss-of-function mutations that affect the coding sequence of exon 3 or 4 of methyl-CpG-binding protein 2 (MECP2). Severe neonatal encephalopathy resulting in death before the age of 2 years is the most common phenotype observed in males affected by a pathogenic MECP2 variant. Mutations in MECP2 exon 1 affecting the MeCP2_e1 isoform are relatively rare causes of RTT in females, and only one case of a male patient with MECP2-related severe neonatal encephalopathy caused by a mutation in MECP2 exon 1 has been reported. This is the first reported case of a male with classic RTT caused by a 5-bp duplication in the open-reading frame of MECP2 exon 1 (NM_001110792.1:c.23_27dup) that introduced a premature stop codon [p.(Ser10Argfs*36)] in the MeCP2_e1 isoform, which has been reported in one female patient with classic RTT. Therefore, both males and females displaying at least some type of MeCP2_e1 mutation may exhibit the classic RTT phenotype. © 2018 Wiley Periodicals, Inc.

Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

International Nuclear Information System (INIS)

Halaban, R.; Moellmann, G.

1990-01-01

Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B lt /B lt ) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B lt mutation renders the protein susceptible to rapid proteolytic degradation

Mutations altering the gammaretrovirus endoproteolytic motif affect glycosylation of the envelope glycoprotein and early events of the virus life cycle

Energy Technology Data Exchange (ETDEWEB)

Argaw, Takele; Wilson, Carolyn A., E-mail: carolyn.wilson@fda.hhs.gov

2015-01-15

Previously, we found that mutation of glutamine to proline in the endoproteolytic cleavage signal of the PERV-C envelope (RQKK to RPKK) resulted in non-infectious vectors. Here, we show that RPKK results in a non-infectious vector when placed in not only a PERV envelope, but also the envelope of a related gammaretrovirus, FeLV-B. The amino acid substitutions do not prevent envelope precursor cleavage, viral core and genome assembly, or receptor binding. Rather, the mutations result in the formation of hyperglycosylated glycoprotein and a reduction in the reverse transcribed minus strand synthesis and undetectable 2-LTR circular DNA in cells exposed to vectors with these mutated envelopes. Our findings suggest novel functions associated with the cleavage signal sequence that may affect trafficking through the glycosylation machinery of the cell. Further, the glycosylation status of the envelope appears to impact post-binding events of the viral life cycle, either membrane fusion, internalization, or reverse transcription. - Highlights: • Env cleavage signal impacts infectivity of gammaretroviruses. • Non-infectious mutants have hyper-glycosylated envelope that bind target cells. • Non-infectious mutants have defects in the formation of the double-stranded DNA. • Env cleavage motif has functions beyond cleavage of the env precursor.

Adipokine zinc-α2-glycoprotein regulated by growth hormone and linked to insulin sensitivity.

Science.gov (United States)

Balaz, Miroslav; Ukropcova, Barbara; Kurdiova, Timea; Gajdosechova, Lucia; Vlcek, Miroslav; Janakova, Zuzana; Fedeles, Jozef; Pura, Mikulas; Gasperikova, Daniela; Smith, Steven R; Tkacova, Ruzena; Klimes, Iwar; Payer, Juraj; Wolfrum, Christian; Ukropec, Jozef

2015-02-01

Hypertrophic obesity is associated with impaired insulin sensitivity and lipid-mobilizing activity of zinc-α2-glycoprotein. Adipose tissue (AT) of growth hormone (GH) -deficient patients is characterized by extreme adipocyte hypertrophy due to defects in AT lipid metabolism. It was hypothesized that zinc-α2-glycoprotein is regulated by GH and mediates some of its beneficial effects in AT. AT from patients with GH deficiency and individuals with obesity-related GH deficit was obtained before and after 5-year and 24-month GH supplementation therapy. GH action was tested in primary human adipocytes. Relationships of GH and zinc-α2-glycoprotein with adipocyte size and insulin sensitivity were evaluated in nondiabetic patients with noncancerous cachexia and hypertrophic obesity. AT in GH-deficient adults displayed a substantial reduction of zinc-α2-glycoprotein. GH therapy normalized AT zinc-α2-glycoprotein. Obesity-related relative GH deficit was associated with almost 80% reduction of zinc-α2-glycoprotein mRNA in AT. GH increased zinc-α2-glycoprotein mRNA in both AT of obese men and primary human adipocytes. Interdependence of GH and zinc-α2-glycoprotein in regulating AT morphology and metabolic phenotype was evident from their relationship with adipocyte size and AT-specific and whole-body insulin sensitivity. The results demonstrate that GH is involved in regulation of AT zinc-α2-glycoprotein; however, the molecular mechanism linking GH and zinc-α2-glycoprotein in AT is yet unknown. © 2014 The Obesity Society.

Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

DEFF Research Database (Denmark)

Meunier, Jean-Christophe; Russell, Rodney S.; Goossens, Vera

2008-01-01

The relative importance of humoral and cellular immunity in the prevention or clearance of hepatitis C virus (HCV) infection is poorly understood. However, there is considerable evidence that neutralizing antibodies are involved in disease control. Here we describe the detailed analysis of human...... monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...... neutralize HCVpp bearing the envelope glycoproteins of genotype 2a. Genotype 3a was not neutralized. The epitopes for both MAbs were mapped to the region encompassing amino acids 313 to 327. In addition, robust neutralization was also observed against cell culture-adapted viruses of genotypes 1a and 2a...

Effect of neuraminidase inhibitor-resistant mutations on pathogenicity of clade 2.2 A/Turkey/15/06 (H5N1) influenza virus in ferrets.

Science.gov (United States)

Ilyushina, Natalia A; Seiler, Jon P; Rehg, Jerold E; Webster, Robert G; Govorkova, Elena A

2010-05-27

The acquisition of neuraminidase (NA) inhibitor resistance by H5N1 influenza viruses has serious clinical implications, as this class of drugs can be an essential component of pandemic control measures. The continuous evolution of the highly pathogenic H5N1 influenza viruses results in the emergence of natural NA gene variations whose impact on viral fitness and NA inhibitor susceptibility are poorly defined. We generated seven genetically stable recombinant clade 2.2 A/Turkey/15/06-like (H5N1) influenza viruses carrying NA mutations located either in the framework residues (E119A, H274Y, N294S) or in close proximity to the NA enzyme active site (V116A, I117V, K150N, Y252H). NA enzyme inhibition assays showed that NA mutations at positions 116, 117, 274, and 294 reduced susceptibility to oseltamivir carboxylate (IC(50)s increased 5- to 940-fold). Importantly, the E119A NA mutation (previously reported to confer resistance in the N2 NA subtype) was stable in the clade 2.2 H5N1 virus background and induced cross-resistance to oseltamivir carboxylate and zanamivir. We demonstrated that Y252H NA mutation contributed for decreased susceptibility of clade 2.2 H5N1 viruses to oseltamivir carboxylate as compared to clade 1 viruses. The enzyme kinetic parameters (V(max), K(m) and K(i)) of the avian-like N1 NA glycoproteins were highly consistent with their IC(50) values. None of the recombinant H5N1 viruses had attenuated virulence in ferrets inoculated with 10(6) EID(50) dose. Most infected ferrets showed mild clinical disease signs that differed in duration. However, H5N1 viruses carrying the E119A or the N294S NA mutation were lethal to 1 of 3 inoculated animals and were associated with significantly higher virus titers (Pinfluenza drugs that target different virus/host factors and can limit the emergence of resistance.

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

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Rafael Simó

Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

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Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

Immunoglobulin-E reactivity to wine glycoproteins in heavy drinkers

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Gonzalez-Quintela, Arturo; Gomez-Rial, Jose; Valcarcel, Catalina

2011-01-01

and biological significance of IgE antibodies to N-glycans from wine glycoproteins in heavy drinkers. A structured questionnaire, skin prick tests, serum IgE levels, IgE-immunoblotting to wine extracts, and basophil activation tests were used to characterize 20 heavy drinkers and 10 control subjects. Eleven...... heavy drinkers (55%) showed IgE binding to proteins in wine extracts. The proteins were identified by mass spectrometry as grape-derived vacuolar invertase and thaumatin-like protein. Immunoblot reactivity was closely associated with the presence of IgE to CCDs and was inhibited by preincubation...... with a glycoconjugate containing bromelain-type N-glycans. The same conjugate, CCD-bearing allergens, and wine extracts activated basophils in patients with high-titer CCD-specific IgE but not in healthy controls. There was no relationship between immunoblot reactivity and consumption of any specific type of wine...

Cooperativity in virus neutralization by human monoclonal antibodies to two adjacent regions located at the amino terminus of hepatitis C virus E2 glycoprotein

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Keck, Zhenyong; Wang, Wenyan; Wang, Yong

2013-01-01

A challenge for hepatitis C virus (HCV) vaccine development is defining conserved epitopes that induce protective antibodies against this highly diverse virus. An envelope glycoprotein (E2) segment located at amino acids (aa) 412 to 423 contains highly conserved neutralizing epitopes. While...... at higher concentrations. However, the overall effect was additive neutralization. A similar pattern was observed when these antibodies were combined to block E2 binding to the HCV coreceptor, CD81. These findings demonstrate that both of these E2 regions participate in epitopes mediating virus...... (HCVcc) with various activities. Although nonneutralizing HC33 HMAbs were isolated, they had lower binding affinities than neutralizing HC33 HMAbs. These antibodies could be converted to neutralizing antibodies by affinity maturation. Unidirectional competition for binding to E2 was observed between HC33...

Expression of variable viruses as herpes simplex glycoprotein D and varicella zoster gE glycoprotein using a novel plasmid based expression system in insect cell

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A.M. Al-Sulaiman

2017-11-01

Full Text Available Several prokaryotic and eukaryotic expression systems have been used for in vitro production of viruses’ proteins. However eukaryotic expression system was always the first choice for production of proteins that undergo post-translational modification such as glycosylation. Recombinant baculoviruses have been widely used as safe vectors to express heterologous genes in the culture of insect cells, but the manipulation involved in creating, titrating, and amplifying viral stocks make it time consuming and laborious. Therefore, to facilitate rapid expression in insect cell, a plasmid based expression system was used to express herpes simplex type 1 glycoprotein D (HSV-1 gD and varicella zoster glycoprotein E (VZV gE. Recombinant plasmids were generated, transfected into insect cells (SF9, and both glycoproteins were expressed 48 h post-infection. A protein with approximately molecular weight of 64-kDa and 98-kDa for HSV-1 gD and VZV gE respectively was expressed and confirmed by SDS. Proteins were detected in insect cells cytoplasm and outer membrane by immunofluorescence. The antigenicity and immunoreactivity of each protein were confirmed by immunoblot and ELISA. Results suggest that this system can be an alternative to the traditional baculovirus expression for small scale expression system in insect cells.

Monoclonal antibodies directed to E1 glycoprotein of rubella virus

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Umino, Y.; Sato, A.; Katow, S.; Matsuno, T.; Sugiura, A.

1985-01-01

We have prepared four monoclonal antibodies to rubella virus E1 glycoprotein. Three nonoverlapping antigenic sites were delineated on E1 protein by competitive binding assays. Antibodies binding to one site were characterized by high hemagglutination inhibition (HI) titer but poor neutralizing activity. The addition of antiglobulin conferred neutralizing activity. Antibodies directed to two other antigenic sites had modest hemolysis inhibition but little or no HI and neutralizing activities. The addition of antiglobulin markedly augmented HI activity but had little effect on neutralizing activity. Epitopes defined by three antibodies were conserved among four rubella virus strains examined. (Author)

Encoding asymmetry of the N-glycosylation motif facilitates glycoprotein evolution.

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Ryan Williams

Full Text Available Protein N-glycosylation is found in all domains of life and has a conserved role in glycoprotein folding and stability. In animals, glycoproteins transit through the Golgi where the N-glycans are trimmed and rebuilt with sequences that bind lectins, an innovation that greatly increases structural diversity and redundancy of glycoprotein-lectin interaction at the cell surface. Here we ask whether the natural tension between increasing diversity (glycan-protein interactions and site multiplicity (backup and status quo might be revealed by a phylogenic examination of glycoproteins and NXS/T(X ≠ P N-glycosylation sites. Site loss is more likely by mutation at Asn encoded by two adenosine (A-rich codons, while site gain is more probable by generating Ser or Thr downstream of an existing Asn. Thus mutations produce sites at novel positions more frequently than the reversal of recently lost sites, and therefore more paths though sequence space are made available to natural selection. An intra-species comparison of secretory and cytosolic proteins revealed a departure from equilibrium in sequences one-mutation-away from NXS/T and in (A content, indicating strong selective pressures and exploration of N-glycosylation positions during vertebrate evolution. Furthermore, secretory proteins have evolved at rates proportional to N-glycosylation site number, indicating adaptive interactions between the N-glycans and underlying protein. Given the topology of the genetic code, mutation of (A is more often nonsynonomous, and Lys, another target of many PTMs, is also encoded by two (A-rich codons. An examination of acetyl-Lys sites in proteins indicated similar evolutionary dynamics, consistent with asymmetry of the target and recognition portions of modified sites. Our results suggest that encoding asymmetry is an ancient mechanism of evolvability that increases diversity and experimentation with PTM site positions. Strong selective pressures on PTMs may have

Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

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Meunier, Jean-Christophe; Russell, Rodney S; Goossens, Vera

2008-01-01

monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...

ALDH2(E487K) mutation increases protein turnover and promotes murine hepatocarcinogenesis.

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Jin, Shengfang; Chen, Jiang; Chen, Lizao; Histen, Gavin; Lin, Zhizhong; Gross, Stefan; Hixon, Jeffrey; Chen, Yue; Kung, Charles; Chen, Yiwei; Fu, Yufei; Lu, Yuxuan; Lin, Hui; Cai, Xiujun; Yang, Hua; Cairns, Rob A; Dorsch, Marion; Su, Shinsan M; Biller, Scott; Mak, Tak W; Cang, Yong

2015-07-21

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) in the liver removes toxic aldehydes including acetaldehyde, an intermediate of ethanol metabolism. Nearly 40% of East Asians inherit an inactive ALDH2*2 variant, which has a lysine-for-glutamate substitution at position 487 (E487K), and show a characteristic alcohol flush reaction after drinking and a higher risk for gastrointestinal cancers. Here we report the characterization of knockin mice in which the ALDH2(E487K) mutation is inserted into the endogenous murine Aldh2 locus. These mutants recapitulate essentially all human phenotypes including impaired clearance of acetaldehyde, increased sensitivity to acute or chronic alcohol-induced toxicity, and reduced ALDH2 expression due to a dominant-negative effect of the mutation. When treated with a chemical carcinogen, these mutants exhibit increased DNA damage response in hepatocytes, pronounced liver injury, and accelerated development of hepatocellular carcinoma (HCC). Importantly, ALDH2 protein levels are also significantly lower in patient HCC than in peritumor or normal liver tissues. Our results reveal that ALDH2 functions as a tumor suppressor by maintaining genomic stability in the liver, and the common human ALDH2 variant would present a significant risk factor for hepatocarcinogenesis. Our study suggests that the ALDH2*2 allele-alcohol interaction may be an even greater human public health hazard than previously appreciated.

Identification of coexistence of BRAF V600E mutation and EZH2 gain specifically in melanoma as a promising target for combination therapy.

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Yu, Huan; Ma, Meng; Yan, Junya; Xu, Longwen; Yu, Jiayi; Dai, Jie; Xu, Tianxiao; Tang, Huan; Wu, Xiaowen; Li, Siming; Lian, Bin; Mao, Lili; Chi, Zhihong; Cui, Chuanliang; Guo, Jun; Kong, Yan

2017-12-04

Coexistence of enhancer of zeste homolog 2 (EZH2) and BRAF gene aberrations has been described in many cancer types. In this study, we aim to explore the coexistence status of BRAF V600E mutation and the copy number variation of EZH2 and explore the potential of this combination as a therapeutic target. A total of 138 cases of melanoma samples harboring BRAF V600E mutation were included, and EZH2 copy numbers were examined by QuantiGenePlex DNA Assays. Clinical pathological distinction between patient groups with or without EZH2 amplification (hereafter referred to as EZH2 gain) was statistically analyzed. The sensitivity of melanoma cell lines and patient-derived xenograft (PDX) models containing BRAF V600E mutation with or without EZH2 gain to vemurafenib (BRAF inhibitor), GSK2816126 (EZH2 inhibitor) and a combination of both agents was evaluated. In our cohort, the coexistence rate of BRAF V600E mutation and EZH2 gain was up to 29.0%, and significant differences in overall survival and disease-free survival were found between no EZH2 copy number gain and gain groups (P = 0.038, P = 0.030), gain and high EZH2 copy number gain groups (P = 0.006, P = 0.010). Combination with BRAF and EZH2 inhibition showed better inhibitory efficacy in melanoma prevention compared with vemurafenib monotherapy. More importantly, this improved therapeutic effect was observed especially in melanoma cell lines and PDX models containing concurrently BRAF V600E mutation and EZH2 gain. Coexistence of BRAF V600E mutation and EZH2 gain is rather prevalent in melanoma. Our findings provided evidence for the feasibility of combination therapy with EZH2 and BRAF inhibitors in melanoma with concurrent BRAF V600E mutation and EZH2 gain.

Cell wall O-glycoproteins and N-glycoproteins: biosynthesis and some functional aspects.

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Eric eNguema-Ona

2014-10-01

Full Text Available Cell wall O-glycoproteins and N-glycoproteins are two types of glycomolecules whose glycans are structurally complex. They are both assembled and modified within the endomembrane system, i.e., the endoplasmic reticulum (ER and the Golgi apparatus, before their transport to their final locations within or outside the cell. In contrast to extensin, the O-glycan chains of arabinogalactan proteins are highly heterogeneous consisting mostly of (i a short oligo-arabinoside chain of three to four residues, and (ii a larger -1,3-linked galactan backbone with -1,6-linked side chains containing galactose, arabinose and, often, fucose, rhamnose or glucuronic acid. The fine structure of arabinogalactan chains varies between, and within plant species, and is important for the functional activities of the glycoproteins. With regards to N-glycans, ER-synthesizing events are highly conserved in all eukaryotes studied so far since they are essential for efficient protein folding. In contrast, evolutionary adaptation of N-glycan processing in the Golgi apparatus has given rise to a variety of organism-specific complex structures. Therefore, plant complex-type N-glycans contain specific glyco-epitopes such as core 1,2-xylose, core 1,3-fucose residues and Lewisa substitutions on the terminal position of the antenna. Like O-glycans, N-glycans of proteins are essential for their stability and function. Mutants affected in the glycan metabolic pathways have provided valuable information on the role of N-/O-glycoproteins in the control of growth, morphogenesis and adaptation to biotic and abiotic stresses. With regards to O-glycoproteins only extensin and arabinogalactan proteins are considered herein. The biosynthesis of these glycoproteins and functional aspects are presented and discussed in this review.

A point mutation in the DNA-binding domain of HPV-2 E2 protein increases its DNA-binding capacity and reverses its transcriptional regulatory activity on the viral early promoter

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Gao Chen

2012-02-01

Full Text Available Abstract Background The human papillomavirus (HPV E2 protein is a multifunctional DNA-binding protein. The transcriptional activity of HPV E2 is mediated by binding to its specific binding sites in the upstream regulatory region of the HPV genomes. Previously we reported a HPV-2 variant from a verrucae vulgaris patient with huge extensive clustered cutaneous, which have five point mutations in its E2 ORF, L118S, S235P, Y287H, S293R and A338V. Under the control of HPV-2 LCR, co-expression of the mutated HPV E2 induced an increased activity on the viral early promoter. In the present study, a series of mammalian expression plasmids encoding E2 proteins with one to five amino acid (aa substitutions for these mutations were constructed and transfected into HeLa, C33A and SiHa cells. Results CAT expression assays indicated that the enhanced promoter activity was due to the co-expressions of the E2 constructs containing A338V mutation within the DNA-binding domain. Western blots analysis demonstrated that the transiently transfected E2 expressing plasmids, regardless of prototype or the A338V mutant, were continuously expressed in the cells. To study the effect of E2 mutations on its DNA-binding activity, a serial of recombinant E2 proteins with various lengths were expressed and purified. Electrophoresis mobility shift assays (EMSA showed that the binding affinity of E2 protein with A338V mutation to both an artificial probe with two E2 binding sites or HPV-2 and HPV-16 promoter-proximal LCR sequences were significantly stronger than that of the HPV-2 prototype E2. Furthermore, co-expression of the construct containing A338V mutant exhibited increased activities on heterologous HPV-16 early promoter P97 than that of prototype E2. Conclusions These results suggest that the mutation from Ala to Val at aa 338 is critical for E2 DNA-binding and its transcriptional regulation.

A novel function of N-linked glycoproteins, alpha-2-HS-glycoprotein and hemopexin: Implications for small molecule compound-mediated neuroprotection.

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Takuya Kanno

Full Text Available Therapeutic agents to the central nervous system (CNS need to be efficiently delivered to the target site of action at appropriate therapeutic levels. However, a limited number of effective drugs for the treatment of neurological diseases has been developed thus far. Further, the pharmacological mechanisms by which such therapeutic agents can protect neurons from cell death have not been fully understood. We have previously reported the novel small-molecule compound, 2-[mesityl(methylamino]-N-[4-(pyridin-2-yl-1H-imidazol-2-yl] acetamide trihydrochloride (WN1316, as a unique neuroprotectant against oxidative injury and a highly promising remedy for the treatment of amyotrophic lateral sclerosis (ALS. One of the remarkable characteristics of WN1316 is that its efficacious doses in ALS mouse models are much less than those against oxidative injury in cultured human neuronal cells. It is also noted that the WN1316 cytoprotective activity observed in cultured cells is totally dependent upon the addition of fetal bovine serum in culture medium. These findings led us to postulate some serum factors being tightly linked to the WN1316 efficacy. In this study, we sieved through fetal bovine serum proteins and identified two N-linked glycoproteins, alpha-2-HS-glycoprotein (AHSG and hemopexin (HPX, requisites to exert the WN1316 cytoprotective activity against oxidative injury in neuronal cells in vitro. Notably, the removal of glycan chains from these molecules did not affect the WN1316 cytoprotective activity. Thus, two glycoproteins, AHSG and HPX, represent a pivotal glycoprotein of the cytoprotective activity for WN1316, showing a concrete evidence for the novel glycan-independent function of serum glycoproteins in neuroprotective drug efficacy.

New truncation mutation of the NR2E3 gene in a Japanese patient with enhanced S-cone syndrome.

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Kuniyoshi, Kazuki; Hayashi, Takaaki; Sakuramoto, Hiroyuki; Mishima, Hiroshi; Tsuneoka, Hiroshi; Tsunoda, Kazushige; Iwata, Takeshi; Shimomura, Yoshikazu

2016-11-01

The enhanced S-cone syndrome (ESCS) is a rare hereditary retinal degeneration that has enhanced short wavelength-sensitive cone (S-cone) functions. The longitudinal clinical course of this disease has been rarely reported, and the genetic aspects of ESCS have not been well investigated in the Japanese population. In this report, we present our clinical and genetic findings for 2 patients with ESCS. The patients were 2 unrelated Japanese men. Standard ophthalmic examinations and mutation screening for the NR2E3 gene were performed. Patient 1 was a 36-year-old man, and his clinical findings were typical of ESCS. His decimal best-corrected visual acuity (BCVA) was 1.0 OD and 0.5 OS after removal of cataracts. Genetic investigations revealed a homozygous truncation frameshift, the p.I307LfsX33 mutation. Patient 2 was an 11-year-old boy when he was first examined by us. His clinical findings were typical of ESCS except for uveitis in the left eye. His decimal BCVA at the age of 39 years was maintained at 1.5 in each eye, although the retinal degeneration and visual field impairments had progressed during the follow-up period. The genetic investigations revealed homozygous mutations of p.R104Q in the NR2E3 gene. The frameshift mutation, p.I307LfsX33, in the NR2E3 gene is a new causative mutation for ESCS. The clinical observations for patient 2 are the longest ever reported. The retinal degeneration caused by this mutation is slowly progressive, and these patients maintained good vision with maintenance of the foveal structure until their late thirties.

The PTPN11 loss-of-function mutation Q510E-Shp2 causes hypertrophic cardiomyopathy by dysregulating mTOR signaling.

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Schramm, Christine; Fine, Deborah M; Edwards, Michelle A; Reeb, Ashley N; Krenz, Maike

2012-01-01

The identification of mutations in PTPN11 (encoding the protein tyrosine phosphatase Shp2) in families with congenital heart disease has facilitated mechanistic studies of various cardiovascular defects. However, the roles of normal and mutant Shp2 in the developing heart are still poorly understood. Furthermore, it remains unclear how Shp2 loss-of-function (LOF) mutations cause LEOPARD Syndrome (also termed Noonan Syndrome with multiple lentigines), which is characterized by congenital heart defects such as pulmonary valve stenosis and hypertrophic cardiomyopathy (HCM). In normal hearts, Shp2 controls cardiomyocyte size by regulating signaling through protein kinase B (Akt) and mammalian target of rapamycin (mTOR). We hypothesized that Shp2 LOF mutations dysregulate this pathway, resulting in HCM. For our studies, we chose the Shp2 mutation Q510E, a dominant-negative LOF mutation associated with severe early onset HCM. Newborn mice with cardiomyocyte-specific overexpression of Q510E-Shp2 starting before birth displayed increased cardiomyocyte sizes, heart-to-body weight ratios, interventricular septum thickness, and cardiomyocyte disarray. In 3-mo-old hearts, interstitial fibrosis was detected. Echocardiographically, ventricular walls were thickened and contractile function was depressed. In ventricular tissue samples, signaling through Akt/mTOR was hyperactivated, indicating that the presence of Q510E-Shp2 led to upregulation of this pathway. Importantly, rapamycin treatment started shortly after birth rescued the Q510E-Shp2-induced phenotype in vivo. If rapamycin was started at 6 wk of age, HCM was also ameliorated. We also generated a second mouse model in which cardiomyocyte-specific Q510E-Shp2 overexpression started after birth. In contrast to the first model, these mice did not develop HCM. In summary, our studies establish a role for mTOR signaling in HCM caused by Q510E-Shp2. Q510E-Shp2 overexpression in the cardiomyocyte population alone was sufficient to

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.

Effect of specific amino acid substitutions in the putative fusion peptide of structural glycoprotein E2 on Classical Swine Fever Virus replication

International Nuclear Information System (INIS)

Fernández-Sainz, I.J.; Largo, E.; Gladue, D.P.; Fletcher, P.; O’Donnell, V.; Holinka, L.G.; Carey, L.B.; Lu, X.; Nieva, J.L.; Borca, M.V.

2014-01-01

E2, along with E rns and E1, is an envelope glycoprotein of Classical Swine Fever Virus (CSFV). E2 is involved in several virus functions: cell attachment, host range susceptibility and virulence in natural hosts. Here we evaluate the role of a specific E2 region, 818 CPIGWTGVIEC 828 , containing a putative fusion peptide (FP) sequence. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how individual amino acid substitutions within this region of E2 may affect replication of BICv. A synthetic peptide representing the complete E2 FP amino acid sequence adopted a β-type extended conformation in membrane mimetics, penetrated into model membranes, and perturbed lipid bilayer integrity in vitro. Similar peptides harboring amino acid substitutions adopted comparable conformations but exhibited different membrane activities. Therefore, a preliminary characterization of the putative FP 818 CPIGWTGVIEC 828 indicates a membrane fusion activity and a critical role in virus replication. - Highlights: • A putative fusion peptide (FP) region in CSFV E2 protein was shown to be critical for virus growth. • Synthetic FPs were shown to efficiently penetrate into lipid membranes using an in vitro model. • Individual residues in the FP affecting virus replication were identified by reverse genetics. • The same FP residues are also responsible for mediating membrane fusion

Effect of specific amino acid substitutions in the putative fusion peptide of structural glycoprotein E2 on Classical Swine Fever Virus replication

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Fernández-Sainz, I.J. [Plum Island Animal Disease Center, ARS, USDA (United States); Largo, E. [Biophysics Unit (CSIC-UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao (Spain); Gladue, D.P.; Fletcher, P. [Plum Island Animal Disease Center, ARS, USDA (United States); O’Donnell, V. [Plum Island Animal Disease Center, ARS, USDA (United States); Plum Island Animal Disease Center, DHS, Greenport, NY 11944 (United States); Holinka, L.G. [Plum Island Animal Disease Center, ARS, USDA (United States); Carey, L.B. [Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), E-08003 Barcelona (Spain); Lu, X. [Plum Island Animal Disease Center, DHS, Greenport, NY 11944 (United States); Nieva, J.L. [Biophysics Unit (CSIC-UPV/EHU), Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080 Bilbao (Spain); Borca, M.V., E-mail: manuel.borca@ars.usda.gov [Plum Island Animal Disease Center, ARS, USDA (United States)

2014-05-15

E2, along with E{sup rns} and E1, is an envelope glycoprotein of Classical Swine Fever Virus (CSFV). E2 is involved in several virus functions: cell attachment, host range susceptibility and virulence in natural hosts. Here we evaluate the role of a specific E2 region, {sup 818}CPIGWTGVIEC{sup 828}, containing a putative fusion peptide (FP) sequence. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how individual amino acid substitutions within this region of E2 may affect replication of BICv. A synthetic peptide representing the complete E2 FP amino acid sequence adopted a β-type extended conformation in membrane mimetics, penetrated into model membranes, and perturbed lipid bilayer integrity in vitro. Similar peptides harboring amino acid substitutions adopted comparable conformations but exhibited different membrane activities. Therefore, a preliminary characterization of the putative FP {sup 818}CPIGWTGVIEC{sup 828} indicates a membrane fusion activity and a critical role in virus replication. - Highlights: • A putative fusion peptide (FP) region in CSFV E2 protein was shown to be critical for virus growth. • Synthetic FPs were shown to efficiently penetrate into lipid membranes using an in vitro model. • Individual residues in the FP affecting virus replication were identified by reverse genetics. • The same FP residues are also responsible for mediating membrane fusion.

In vitro neutralization of HCV by goat antibodies against peptides encompassing regions downstream of HVR-1 of E2 glycoprotein.

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Tabll, Ashraf A; Atef, Khaled; Bader El Din, Noha G; El Abd, Yasmine S; Salem, Ahmed; Sayed, Ahmed A; Dawood, Reham M; Omran, Moataza H; El-Awady, Mostafa K

2014-01-01

This article aims at testing several in vitro systems with various viral sources and cell lines for propagation of HCV to evaluate goat antibodies raised against three E2 epitopes in viral neutralization experiments. Four human cell lines (Huh-7, Huh-7.5, HepG2, and CaCo2) were tested using two different HCV viral sources; Genotype 4 infected sera and J6/JFH HCV cc particles. Neutralization capacity of goat Abs against conserved E2 epitopes; p412 (a.a 412-419), p517 (a.a 517-531), and p430 (a.a 430-447) were examined in the above mentioned in vitro systems. Although infection with patients' sera seems to mimic the in vitro situation, it has limited replication rates as compared with HCV cc particularly in Huh7.5 cells. Non-HCV adapted Huh-7 cells were also found susceptible for transfection with J6/JFH virus but at much slower kinetics. The results of the neutralization assay showed that anti p412 and anti p517 were highly neutralizing to HCVcc. Our data demonstrate that antibodies directed against the viral surface glycoprotein E2 reduced the infectivity of the J6/JFH virus and are promising agents for immunotherapy and HCV vaccine development.

Effect of neuraminidase inhibitor-resistant mutations on pathogenicity of clade 2.2 A/Turkey/15/06 (H5N1 influenza virus in ferrets.

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Natalia A Ilyushina

2010-05-01

Full Text Available The acquisition of neuraminidase (NA inhibitor resistance by H5N1 influenza viruses has serious clinical implications, as this class of drugs can be an essential component of pandemic control measures. The continuous evolution of the highly pathogenic H5N1 influenza viruses results in the emergence of natural NA gene variations whose impact on viral fitness and NA inhibitor susceptibility are poorly defined. We generated seven genetically stable recombinant clade 2.2 A/Turkey/15/06-like (H5N1 influenza viruses carrying NA mutations located either in the framework residues (E119A, H274Y, N294S or in close proximity to the NA enzyme active site (V116A, I117V, K150N, Y252H. NA enzyme inhibition assays showed that NA mutations at positions 116, 117, 274, and 294 reduced susceptibility to oseltamivir carboxylate (IC(50s increased 5- to 940-fold. Importantly, the E119A NA mutation (previously reported to confer resistance in the N2 NA subtype was stable in the clade 2.2 H5N1 virus background and induced cross-resistance to oseltamivir carboxylate and zanamivir. We demonstrated that Y252H NA mutation contributed for decreased susceptibility of clade 2.2 H5N1 viruses to oseltamivir carboxylate as compared to clade 1 viruses. The enzyme kinetic parameters (V(max, K(m and K(i of the avian-like N1 NA glycoproteins were highly consistent with their IC(50 values. None of the recombinant H5N1 viruses had attenuated virulence in ferrets inoculated with 10(6 EID(50 dose. Most infected ferrets showed mild clinical disease signs that differed in duration. However, H5N1 viruses carrying the E119A or the N294S NA mutation were lethal to 1 of 3 inoculated animals and were associated with significantly higher virus titers (P<0.01 and inflammation in the lungs compared to the wild-type virus. Our results suggest that highly pathogenic H5N1 variants carrying mutations within the NA active site that decrease susceptibility to NA inhibitors may possess increased

STAT3 mutations correlated with hyper-IgE syndrome lead to ...

Indian Academy of Sciences (India)

Of all the causes identified for the disease hyper-immunoglobulinemia E syndrome (HIES), a homozygous mutation in tyrosine kinase2 (TYK2) and heterozygous mutations in STAT3 are implicated the defects in Jak/STAT signalling pathway in the pathogenesis of HIES. Mutations of STAT3 have been frequently clinically ...

ERBB2 mutation is associated with a worse prognosis in patients with CDH1 altered invasive lobular cancer of the breast.

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Ping, Zheng; Siegal, Gene P; Harada, Shuko; Eltoum, Isam-Eldin; Youssef, Mariam; Shen, Tiansheng; He, Jianbo; Huang, Yingjie; Chen, Dongquan; Li, Yiping; Bland, Kirby I; Chang, Helena R; Shen, Dejun

2016-12-06

E-cadherin (CDH1) is a glycoprotein that mediates adhesion between epithelial cells and also suppresses cancer invasion. Mutation or deletion of the CDH1 gene has been reported in 30-60% cases of invasive lobular carcinoma (ILC). However, little is known about genomic differences between ILC with and without a CDH1 alteration. Therefore, we analyzed whole genome sequencing data of 169 ILC cases from The Cancer Genome Atlas (TCGA) to address this deficiency. Our study shows that CDH1 gene was altered in 59.2% (100/169) of ILC. No significant difference was identified between CDH1-altered and -unaltered ILC cases for any of the examined demographic, clinical or pathologic characteristics, including histologic grade, tumor stage, lymph node metastases, or ER/PR/HER2 states. Seven recurrent mutations (PTEN, MUC16, ERBB2, FAT4, PCDHGA2, HERC1 and FLNC) and four chromosomal changes with recurrent copy number variation (CNV) (11q13, 17q12-21, 8p11 and 8q11) were found in ILC, which correlated with a positive or negative CDH1 alteration status, respectively. The prevalence of the most common breast cancer driver abnormalities including TP53 and PIK3CA mutations and MYC and ERBB2 amplifications showed no difference between the two groups. However, CDH1-altered ILC with an ERBB2 mutation shows a significantly worse prognosis compared to its counterparts without such a mutation. Our study suggests that CDH1-altered ILC patients with ERBB2 mutations may represent an actionable group of patients who could benefit from targeted breast cancer therapy.

Analysis of a conserved RGE/RGD motif in HCV E2 in mediating entry

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Rong Lijun

2009-01-01

Full Text Available Abstract Background Hepatitis C virus (HCV encodes two transmembrane glycoproteins E1 and E2 which form a heterodimer. E1 is believed to mediate fusion while E2 has been shown to bind cellular receptors. It is clear that HCV uses a multi-receptor complex to gain entry into susceptible cells, however key elements of this complex remain elusive. In this study, the role of a highly conserved RGE/RGD motif of HCV E2 glycoprotein in viral entry was examined. The effect of each substitution mutation in this motif was tested by challenging susceptible cell lines with mutant HCV E1E2 pseudotyped viruses generated using a lentiviral system (HCVpp. In addition to assaying infectivity, producer cell expression and HCVpp incorporation of HCV E2 proteins, CD81 binding profiles, and conformation of mutants were examined. Results Based on these characteristics, mutants either displayed wt characteristics (high infectivity [≥ 90% of wt HCVpp], CD81 binding, E1E2 expression, and incorporation into viral particles and proper conformation or very low infectivity (≤ 20% of wt HCVpp. Only amino acid substitutions of the 3rd position (D or E resulted in wt characteristics as long as the negative charge was maintained or a neutral alanine was introduced. A change in charge to a positive lysine, disrupted HCVpp infectivity at this position. Conclusion Although most amino acid substitutions within this conserved motif displayed greatly reduced HCVpp infectivity, they retained soluble CD81 binding, proper E2 conformation, and incorporation into HCVpp. Our results suggest that although RGE/D is a well-defined integrin binding motif, in this case the role of these three hyperconserved amino acids does not appear to be integrin binding. As the extent of conservation of this region extends well beyond these three amino acids, we speculate that this region may play an important role in the structure of HCV E2 or in mediating the interaction with other factor(s during

Multiple linear B-cell epitopes of classical swine fever virus glycoprotein E2 expressed in E.coli as multiple epitope vaccine induces a protective immune response

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Wei Jian-Chao

2011-07-01

Full Text Available Abstract Classical swine fever is a highly contagious disease of swine caused by classical swine fever virus, an OIE list A pathogen. Epitope-based vaccines is one of the current focuses in the development of new vaccines against classical swine fever virus (CSFV. Two B-cell linear epitopes rE2-ba from the E2 glycoprotein of CSFV, rE2-a (CFRREKPFPHRMDCVTTTVENED, aa844-865 and rE2-b (CKEDYRYAISSTNEIGLLGAGGLT, aa693-716, were constructed and heterologously expressed in Escherichia coli as multiple epitope vaccine. Fifteen 6-week-old specified-pathogen-free (SPF piglets were intramuscularly immunized with epitopes twice at 2-week intervals. All epitope-vaccinated pigs could mount an anamnestic response after booster vaccination with neutralizing antibody titers ranging from 1:16 to 1:256. At this time, the pigs were subjected to challenge infection with a dose of 1 × 106 TCID50 virulent CSFV strain. After challenge infection, all of the rE2-ba-immunized pigs were alive and without symptoms or signs of CSF. In contrast, the control pigs continuously exhibited signs of CSF and had to be euthanized because of severe clinical symptoms at 5 days post challenge infection. The data from in vivo experiments shown that the multiple epitope rE2-ba shown a greater protection (similar to that of HCLV vaccine than that of mono-epitope peptide(rE2-a or rE2-b. Therefore, The results demonstrated that this multiple epitope peptide expressed in a prokaryotic system can be used as a potential DIVA (differentiating infected from vaccinated animals vaccine. The E.coli-expressed E2 multiple B-cell linear epitopes retains correct immunogenicity and is able to induce a protective immune response against CSFV infection.

Can mutational GC-pressure create new linear B-cell epitopes in herpes simplex virus type 1 glycoprotein B?

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Khrustalev, Vladislav Victorovich

2009-01-01

We showed that GC-content of nucleotide sequences coding for linear B-cell epitopes of herpes simplex virus type 1 (HSV1) glycoprotein B (gB) is higher than GC-content of sequences coding for epitope-free regions of this glycoprotein (G + C = 73 and 64%, respectively). Linear B-cell epitopes have been predicted in HSV1 gB by BepiPred algorithm ( www.cbs.dtu.dk/services/BepiPred ). Proline is an acrophilic amino acid residue (it is usually situated on the surface of protein globules, and so included in linear B-cell epitopes). Indeed, the level of proline is much higher in predicted epitopes of gB than in epitope-free regions (17.8% versus 1.8%). This amino acid is coded by GC-rich codons (CCX) that can be produced due to nucleotide substitutions caused by mutational GC-pressure. GC-pressure will also lead to disappearance of acrophobic phenylalanine, isoleucine, methionine and tyrosine coded by GC-poor codons. Results of our "in-silico directed mutagenesis" showed that single nonsynonymous substitutions in AT to GC direction in two long epitope-free regions of gB will cause formation of new linear epitopes or elongation of previously existing epitopes flanking these regions in 25% of 539 possible cases. The calculations of GC-content and amino acid content have been performed by CodonChanges algorithm ( www.barkovsky.hotmail.ru ).

Presence of calreticulin mutations in JAK2-negative polycythemia vera.

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Broséus, Julien; Park, Ji-Hye; Carillo, Serge; Hermouet, Sylvie; Girodon, François

2014-12-18

Calreticulin (CALR) mutations have been reported in Janus kinase 2 (JAK2)- and myeloproliferative leukemia (MPL)-negative essential thrombocythemia and primary myelofibrosis. In contrast, no CALR mutations have ever been reported in the context of polycythemia vera (PV). Here, we describe 2 JAK2(V617F)-JAK2(exon12)-negative PV patients who presented with a CALR mutation in peripheral granulocytes at the time of diagnosis. In both cases, the CALR mutation was a 52-bp deletion. Single burst-forming units-erythroid (BFU-E) from 1 patient were grown in vitro and genotyped: the same CALR del 52-bp mutation was noted in 31 of the 37 colonies examined; 30 of 31 BFU-E were heterozygous for CALR del 52 bp, and 1 of 31 BFU-E was homozygous for CALR del 52 bp. In summary, although unknown mutations leading to PV cannot be ruled out, our results suggest that CALR mutations can be associated with JAK2-negative PV. © 2014 by The American Society of Hematology.

Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

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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.

Nonsense mutation in the glycoprotein Ibα coding sequence associated with Bernard-Soulier syndrome

International Nuclear Information System (INIS)

Ware, J.; Russell, S.R.; Vicente, V.; Scharf, R.E.; Tomer, A.; McMillian, R.; Ruggeri, Z.M.

1990-01-01

Three distinct gene products, the α and β chains of glycoprotein (GP) Ib and GP IX, constitute the platelet membrane GP Ib-IX complex, a receptor for von Willebrand factor and thrombin involved in platelet adhesion and aggregation. Defective function of the GP Ib-IX complex is the hallmark of a rare congenital bleeding disorder of still undefined pathogenesis, the Bernard-Soulier syndrome. The authors have analyzed the molecular basis of the disease in one patient in whom immunoblotting of solubilized platelets demonstrated absence of normal GP Ibα but presence of a smaller immunoreactive species. The truncated polypeptide was also present, along with normal protein, in platelets from the patient's mother and two of his four children. Genetic characterization identified a nucleotide transition changing the Trp-343 codon (TGG) to a nonsense codon (TGA). Such a mutation explains the origin of the smaller GP Ibα, which by lacking half of the sequence on the carboxyl-terminal side, including the transmembrane domain, cannot be properly inserted in the platelet membrane. Both normal and mutant codons were found in the patient, suggesting that he is a compound heterozygote with a still unidentified defect in the other GP Ibα allele. Nonsense mutation and truncated GP Ibα polypeptide were found to cosegregate in four individuals through three generations and were associated with either Bernard-Soulier syndrome or carrier state phenotype. The molecular abnormality demonstrated in this family provides evidence that defective synthesis of GP Ibα alters the membrane expression of the GP Ib-IX complex and may be responsible for Bernard-Soulier syndrome

Blocking herpes simplex virus 2 glycoprotein E immune evasion as an approach to enhance efficacy of a trivalent subunit antigen vaccine for genital herpes.

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Awasthi, Sita; Huang, Jialing; Shaw, Carolyn; Friedman, Harvey M

2014-08-01

Herpes simplex virus 2 (HSV-2) subunit antigen vaccines targeting virus entry molecules have failed to prevent genital herpes in human trials. Our approach is to include a virus entry molecule and add antigens that block HSV-2 immune evasion. HSV-2 glycoprotein C (gC2) is an immune evasion molecule that inhibits complement. We previously reported that adding gC2 to gD2 improved vaccine efficacy compared to the efficacy of either antigen alone in mice and guinea pigs. Here we demonstrate that HSV-2 glycoprotein E (gE2) functions as an immune evasion molecule by binding the IgG Fc domain. HSV-2 gE2 is synergistic with gC2 in protecting the virus from antibody and complement neutralization. Antibodies produced by immunization with gE2 blocked gE2-mediated IgG Fc binding and cell-to-cell spread. Mice immunized with gE2 were only partially protected against HSV-2 vaginal challenge in mice; however, when gE2 was added to gC2/gD2 to form a trivalent vaccine, neutralizing antibody titers with and without complement were significantly higher than those produced by gD2 alone. Importantly, the trivalent vaccine protected the dorsal root ganglia (DRG) of 32/33 (97%) mice between days 2 and 7 postchallenge, compared with 27/33 (82%) in the gD2 group. The HSV-2 DNA copy number was significantly lower in mice immunized with the trivalent vaccine than in those immunized with gD2 alone. The extent of DRG protection using the trivalent vaccine was better than what we previously reported for gC2/gD2 immunization. Therefore, gE2 is a candidate antigen for inclusion in a multivalent subunit vaccine that attempts to block HSV-2 immune evasion. Herpes simplex virus is the most common cause of genital ulcer disease worldwide. Infection results in emotional distress for infected individuals and their partners, is life threatening for infants exposed to herpes during childbirth, and greatly increases the risk of individuals acquiring and transmitting HIV infection. A vaccine that prevents

Nipah virus infection and glycoprotein targeting in endothelial cells

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Maisner Andrea

2010-11-01

Full Text Available Abstract Background The highly pathogenic Nipah virus (NiV causes fatal respiratory and brain infections in animals and humans. The major hallmark of the infection is a systemic endothelial infection, predominantly in the CNS. Infection of brain endothelial cells allows the virus to overcome the blood-brain-barrier (BBB and to subsequently infect the brain parenchyma. However, the mechanisms of NiV replication in endothelial cells are poorly elucidated. We have shown recently that the bipolar or basolateral expression of the NiV surface glycoproteins F and G in polarized epithelial cell layers is involved in lateral virus spread via cell-to-cell fusion and that correct sorting depends on tyrosine-dependent targeting signals in the cytoplasmic tails of the glycoproteins. Since endothelial cells share many characteristics with epithelial cells in terms of polarization and protein sorting, we wanted to elucidate the role of the NiV glycoprotein targeting signals in endothelial cells. Results As observed in vivo, NiV infection of endothelial cells induced syncytia formation. The further finding that infection increased the transendothelial permeability supports the idea of spread of infection via cell-to-cell fusion and endothelial cell damage as a mechanism to overcome the BBB. We then revealed that both glycoproteins are expressed at lateral cell junctions (bipolar, not only in NiV-infected primary endothelial cells but also upon stable expression in immortalized endothelial cells. Interestingly, mutation of tyrosines 525 and 542/543 in the cytoplasmic tail of the F protein led to an apical redistribution of the protein in endothelial cells whereas tyrosine mutations in the G protein had no effect at all. This fully contrasts the previous results in epithelial cells where tyrosine 525 in the F, and tyrosines 28/29 in the G protein were required for correct targeting. Conclusion We conclude that the NiV glycoprotein distribution is responsible for

Crystal structure of the pestivirus envelope glycoprotein E(rns) and mechanistic analysis of its ribonuclease activity.

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Krey, Thomas; Bontems, Francois; Vonrhein, Clemens; Vaney, Marie-Christine; Bricogne, Gerard; Rümenapf, Till; Rey, Félix A

2012-05-09

Pestiviruses, which belong to the Flaviviridae family of RNA viruses, are important agents of veterinary diseases causing substantial economical losses in animal farming worldwide. Pestivirus particles display three envelope glycoproteins at their surface: E(rns), E1, and E2. We report here the crystal structure of the catalytic domain of E(rns), the ribonucleolytic activity of which is believed to counteract the innate immunity of the host. The structure reveals a three-dimensional fold corresponding to T2 ribonucleases from plants and fungi. Cocrystallization experiments with mono- and oligonucleotides revealed the structural basis for substrate recognition at two binding sites previously identified for T2 RNases. A detailed analysis of poly-U cleavage products using (31)P-NMR and size exclusion chromatography, together with molecular docking studies, provides a comprehensive mechanistic picture of E(rns) activity on its substrates and reveals the presence of at least one additional nucleotide binding site. Copyright © 2012 Elsevier Ltd. All rights reserved.

Darier disease mutation E917K of SERCA2b relieves the inhibitory influence of the 11th transmembrane segment

DEFF Research Database (Denmark)

Mikkelsen, Stine; Holdensen, Anne Nyholm; Vangheluwe, Peter

Mutation E917K of the Sarco(endo)plasmic Reticulum Ca2+-ATPase isoform 2b (SERCA2b) causes Darier disease, an autosomal dominantly inherited skin disease also denoted as Keratosis Follicularis or Darier-White disease. SERCA is encoded by three genes ATP2A1, ATP2A2 and ATP2A3 giving rise to the pr......Mutation E917K of the Sarco(endo)plasmic Reticulum Ca2+-ATPase isoform 2b (SERCA2b) causes Darier disease, an autosomal dominantly inherited skin disease also denoted as Keratosis Follicularis or Darier-White disease. SERCA is encoded by three genes ATP2A1, ATP2A2 and ATP2A3 giving rise...

Mutations in the DNA-binding domain of NR2E3 affect in vivo dimerization and interaction with CRX.

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Raphael Roduit

Full Text Available BACKGROUND: NR2E3 (PNR is an orphan nuclear receptor essential for proper photoreceptor determination and differentiation. In humans, mutations in NR2E3 have been associated with the recessively inherited enhanced short wavelength sensitive (S- cone syndrome (ESCS and, more recently, with autosomal dominant retinitis pigmentosa (adRP. NR2E3 acts as a suppressor of the cone generation program in late mitotic retinal progenitor cells. In adult rod photoreceptors, NR2E3 represses cone-specific gene expression and acts in concert with the transcription factors CRX and NRL to activate rod-specific genes. NR2E3 and CRX have been shown to physically interact in vitro through their respective DNA-binding domains (DBD. The DBD also contributes to homo- and heterodimerization of nuclear receptors. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed NR2E3 homodimerization and NR2E3/CRX complex formation in an in vivo situation by Bioluminescence Resonance Energy Transfer (BRET(2. NR2E3 wild-type protein formed homodimers in transiently transfected HEK293T cells. NR2E3 homodimerization was impaired in presence of disease-causing mutations in the DBD, except for the p.R76Q and p.R104W mutant proteins. Strikingly, the adRP-linked p.G56R mutant protein interacted with CRX with a similar efficiency to that of NR2E3 wild-type and p.R311Q proteins. In contrast, all other NR2E3 DBD-mutant proteins did not interact with CRX. The p.G56R mutant protein was also more effective in abolishing the potentiation of rhodospin gene transactivation by the NR2E3 wild-type protein. In addition, the p.G56R mutant enhanced the transrepression of the M- and S-opsin promoter, while all other NR2E3 DBD-mutants did not. CONCLUSIONS/SIGNIFICANCE: These results suggest different disease mechanisms in adRP- and ESCS-patients carrying NR2E3 mutations. Titration of CRX by the p.G56R mutant protein acting as a repressor in trans may account for the severe clinical phenotype in adRP patients.

Analysis of glycoprotein-derived oligosaccharides in glycoproteins detected on two-dimensional gel by capillary electrophoresis using on-line concentration method.

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Kamoda, Satoru; Nakanishi, Yasuharu; Kinoshita, Mitsuhiro; Ishikawa, Rika; Kakehi, Kazuaki

2006-02-17

Capillary electrophoresis (CE) is an effective tool to analyze carbohydrate mixture derived from glycoproteins with high resolution. However, CE has a disadvantage that a few nanoliters of a sample solution are injected to a narrow capillary. Therefore, we have to prepare a sample solution of high concentration for CE analysis. In the present study, we applied head column field-amplified sample stacking method to the analysis of N-linked oligosaccharides derived from glycoprotein separated by two-dimensional gel electrophoresis. Model studies demonstrated that we achieved 60-360 times concentration effect on the analysis of carbohydrate chains labeled with 3-aminobenzoic acid (3-AA). The method was applied to the analysis of N-linked oligosaccharides from glycoproteins separated and detected on PAGE gel. Heterogeneity of alpha1-acid glycoprotein (AGP), i.e. glycoforms, was examined by 2D-PAGE and N-linked oligosaccharides were released by in-gel digestion with PNGase F. The released oligosaccharides were derivatized with 3-AA and analyzed by CE. The results showed that glycoforms having lower pI values contained a larger amount of tetra- and tri-antennary oligosaccharides. In contrast, glycoforms having higher pI values contained bi-antennary oligosaccharides abundantly. The result clearly indicated that the spot of a glycoprotein glycoform detected by Coomassie brilliant blue staining on 2D-PAGE gel is sufficient for quantitative profiling of oligosaccharides.

The NS1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease.

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Andrew K I Falconar

Full Text Available Antibody-enhanced replication (AER of dengue type-2 virus (DENV-2 strains and production of antibody-enhanced disease (AED was tested in out-bred mice. Polyclonal antibodies (PAbs generated against the nonstructural-1 (NS1 glycoprotein candidate vaccine of the New Guinea-C (NG-C or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (<0.5 LD₅₀ of the DENV-2 NSx strain, but not the NG-C strain, they all generated dramatic and lethal DENV-2 AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS, displayed by diffuse alveolar damage (DAD resulting from i dramatic interstitial alveolar septa-thickening with mononuclear cells, ii some hyperplasia of alveolar type-II pneumocytes, iii copious intra-alveolar protein secretion, iv some hyaline membrane-covered alveolar walls, and v DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human "severe dengue" cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines

Generation of a novel live rabies vaccine strain with a high level of safety by introducing attenuating mutations in the nucleoprotein and glycoprotein.

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Nakagawa, Keisuke; Nakagawa, Kento; Omatsu, Tsutomu; Katayama, Yukie; Oba, Mami; Mitake, Hiromichi; Okada, Kazuma; Yamaoka, Satoko; Takashima, Yasuhiro; Masatani, Tatsunori; Okadera, Kota; Ito, Naoto; Mizutani, Tetsuya; Sugiyama, Makoto

2017-10-09

The current live rabies vaccine SAG2 is attenuated by only one mutation (Arg-to-Glu) at position 333 in the glycoprotein (G333). This fact generates a potential risk of the emergence of a pathogenic revertant by a back mutation at this position during viral propagation in the body. To circumvent this risk, it is desirable to generate a live vaccine strain highly and stably attenuated by multiple mutations. However, the information on attenuating mutations other than that at G333 is very limited. We previously reported that amino acids at positions 273 and 394 in the nucleoprotein (N273/394) (Leu and His, respectively) of fixed rabies virus Ni-CE are responsible for the attenuated phenotype by enhancing interferon (IFN)/chemokine gene expressions in infected neural cells. In this study, we found that amino acid substitutions at N273/394 (Phe-to-Leu and Tyr-to-His, respectively) attenuated the pathogenicity of the oral live vaccine ERA, which has a virulent-type Arg at G333. Then we generated ERA-N273/394-G333 attenuated by the combination of the above attenuating mutations at G333 and N273/394, and checked its safety. Similar to the ERA-G333, which is attenuated by only the mutation at G333, ERA-N273/394-G333 did not cause any symptoms in adult mice after intracerebral inoculation, indicating a low level of residual pathogenicity of ERA-N273/394-G333. Further examination revealed that infection with ERA-N273/394-G333 induces IFN-β and CXCL10 mRNA expressions more strongly than ERA-G333 infection in a neuroblastoma cell line. Importantly, we found that the ERA-N273/394-G333 stain has a lower risk for emergence of a pathogenic revertant than does the ERA-G333. These results indicate that ERA-N273/394-G333 has a potential to be a promising candidate for a live rabies vaccine strain with a high level of safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification of syncytial mutations in a clinical isolate of herpes simplex virus 2

International Nuclear Information System (INIS)

Muggeridge, Martin I.; Grantham, Michael L.; Johnson, F. Brent

2004-01-01

Small polykaryocytes resulting from cell fusion are found in herpes simplex virus (HSV) lesions in patients, but their significance for viral spread and pathogenesis is unclear. Although syncytial variants causing extensive fusion in tissue culture can be readily isolated from laboratory strains, they are rarely found in clinical isolates, suggesting that extensive cell fusion may be deleterious in vivo. Syncytial mutations have previously been identified for several laboratory strains, but not for clinical isolates of HSV type 2. To address this deficiency, we studied a recent syncytial clinical isolate, finding it to be a mixture of two syncytial and one nonsyncytial strain. The two syncytial strains have novel mutations in glycoprotein B, and in vitro cell fusion assays confirmed that they are responsible for syncytium formation. This panel of clinical strains may be ideal for examining the effect of increased cell fusion on pathogenesis

DUSP4/MKP2 overexpression is associated with BRAFV600E mutation and aggressive behavior of papillary thyroid cancer

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Ma B

2016-04-01

Full Text Available Ben Ma,1,2,* Rongliang Shi,1–3,* Shuwen Yang,1,2 Li Zhou,1,2 Ning Qu,1,2 Tian Liao,1,2 Yu Wang,1,2 Yulong Wang,1,2 Qinghai Ji1,2 1Department of Head and Neck Surgery, Fudan University Shanghai Cancer Center, 2Department of Oncology, Shanghai Medical College, 3Department of General Surgery, Fudan University, Minhang Hospital, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The study was performed to retrospectively analyze the correlation of dual specificity phosphatase 4 (DUSP4 expression with clinicopathological variables and BRAFV600E mutation to better characterize the potential role of DUSP4 as a biomarker in papillary thyroid cancer (PTC. Patients (n=120 who underwent surgery for PTC at Fudan University Shanghai Cancer Center (FUSCC were enrolled in this study, and a validation cohort from The Cancer Genome Atlas (TCGA database was identified to confirm the preliminary findings in our study. We investigated DUSP4 expression at the mRNA level in PTC tissues and adjacent normal tissues using real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR. BRAFV600E mutation analysis was also performed in PTC tissues using Sanger sequencing. Initially, we compared PTC tissues with paired normal tissues in DUSP4 expression using Student’s t-test, and then analyzed the correlation of DUSP4 with clinicopathological variables and BRAFV600E mutation in PTC using Mann–Whitney U, Kruskal–Wallis, χ2, and Fisher’s exact tests. Human-derived thyroid cell lines were also used to verify our findings. DUSP4 was significantly overexpressed in PTC tissues compared with the adjacent normal tissues (P<0.001. High DUSP4 expression showed a significant association with lymph node metastasis and extrathyroidal extension in both FUSCC and TCGA cohorts, and DUSP4 overexpression was an independent risk factor for lymph node metastasis in multivariate analysis. Additionally, DUSP4 expression

Development of glycoprotein capture-based label-free method for the high-throughput screening of differential glycoproteins in hepatocellular carcinoma.

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Chen, Rui; Tan, Yexiong; Wang, Min; Wang, Fangjun; Yao, Zhenzhen; Dong, Liwei; Ye, Mingliang; Wang, Hongyang; Zou, Hanfa

2011-07-01

A robust, reproducible, and high throughput method was developed for the relative quantitative analysis of glycoprotein abundances in human serum. Instead of quantifying glycoproteins by glycopeptides in conventional quantitative glycoproteomics, glycoproteins were quantified by nonglycosylated peptides derived from the glycoprotein digest, which consists of the capture of glycoproteins in serum samples and the release of nonglycopeptides by trypsin digestion of captured glycoproteins followed by two-dimensional liquid chromatography-tandem MS analysis of released peptides. Protein quantification was achieved by comparing the spectrum counts of identified nonglycosylated peptides of glycoproteins between different samples. This method was demonstrated to have almost the same specificity and sensitivity in glycoproteins quantification as capture at glycopeptides level. The differential abundance of proteins present at as low as nanogram per milliliter levels was quantified with high confidence. The established method was applied to the analysis of human serum samples from healthy people and patients with hepatocellular carcinoma (HCC) to screen differential glycoproteins in HCC. Thirty eight glycoproteins were found with substantial concentration changes between normal and HCC serum samples, including α-fetoprotein, the only clinically used marker for HCC diagnosis. The abundance changes of three glycoproteins, i.e. galectin-3 binding protein, insulin-like growth factor binding protein 3, and thrombospondin 1, which were associated with the development of HCC, were further confirmed by enzyme-linked immunosorbent assay. In conclusion, the developed method was an effective approach to quantitatively analyze glycoproteins in human serum and could be further applied in the biomarker discovery for HCC and other cancers.

The amino-terminus of the hepatitis C virus (HCV p7 viroporin and its cleavage from glycoprotein E2-p7 precursor determine specific infectivity and secretion levels of HCV particle types.

Directory of Open Access Journals (Sweden)

Solène Denolly

2017-12-01

Full Text Available Viroporins are small transmembrane proteins with ion channel activities modulating properties of intracellular membranes that have diverse proviral functions. Hepatitis C virus (HCV encodes a viroporin, p7, acting during assembly, envelopment and secretion of viral particles (VP. HCV p7 is released from the viral polyprotein through cleavage at E2-p7 and p7-NS2 junctions by signal peptidase, but also exists as an E2p7 precursor, of poorly defined properties. Here, we found that ectopic p7 expression in HCVcc-infected cells reduced secretion of particle-associated E2 glycoproteins. Using biochemical assays, we show that p7 dose-dependently slows down the ER-to-Golgi traffic, leading to intracellular retention of E2, which suggested that timely E2p7 cleavage and p7 liberation are critical events to control E2 levels. By studying HCV mutants with accelerated E2p7 processing, we demonstrate that E2p7 cleavage controls E2 intracellular expression and secretion levels of nucleocapsid-free subviral particles and infectious virions. In addition, our imaging data reveal that, following p7 liberation, the amino-terminus of p7 is exposed towards the cytosol and coordinates the encounter between NS5A and NS2-based assembly sites loaded with E1E2 glycoproteins, which subsequently leads to nucleocapsid envelopment. We identify punctual mutants at p7 membrane interface that, by abrogating NS2/NS5A interaction, are defective for transmission of infectivity owing to decreased secretion of core and RNA and to increased secretion of non/partially-enveloped particles. Altogether, our results indicate that the retarded E2p7 precursor cleavage is essential to regulate the intracellular and secreted levels of E2 through p7-mediated modulation of the cell secretory pathway and to unmask critical novel assembly functions located at p7 amino-terminus.

CMS-dependent prognostic impact of KRAS and BRAFV600E mutations in primary colorectal cancer.

Science.gov (United States)

Smeby, J; Sveen, A; Merok, M A; Danielsen, S A; Eilertsen, I A; Guren, M G; Dienstmann, R; Nesbakken, A; Lothe, R A

2018-05-01

The prognostic impact of KRAS and BRAFV600E mutations in primary colorectal cancer (CRC) varies with microsatellite instability (MSI) status. The gene expression-based consensus molecular subtypes (CMSs) of CRC define molecularly and clinically distinct subgroups, and represent a novel stratification framework in biomarker analysis. We investigated the prognostic value of these mutations within the CMS groups. Totally 1197 primary tumors from a Norwegian series of CRC stage I-IV were analyzed for MSI and mutation status in hotspots in KRAS (codons 12, 13 and 61) and BRAF (codon 600). A subset was analyzed for gene expression and confident CMS classification was obtained for 317 samples. This cohort was expanded with clinical and molecular data, including CMS classification, from 514 patients in the publically available dataset GSE39582. Gene expression signatures associated with KRAS and BRAFV600E mutations were used to evaluate differential impact of mutations on gene expression among the CMS groups. BRAFV600E and KRAS mutations were both associated with inferior 5-year overall survival (OS) exclusively in MSS tumors (BRAFV600E mutation versus KRAS/BRAF wild-type: Hazard ratio (HR) 2.85, P CMS1, leading to negative prognostic impact in this subtype (OS: BRAFV600E mutation versus wild-type: HR 7.73, P = 0.001). In contrast, the poor prognosis of KRAS mutations was limited to MSS tumors with CMS2/CMS3 epithelial-like gene expression profiles (OS: KRAS mutation versus wild-type: HR 1.51, P = 0.011). The subtype-specific prognostic associations were substantiated by differential effects of BRAFV600E and KRAS mutations on gene expression signatures according to the MSI status and CMS group. BRAFV600E mutations are enriched and associated with metastatic disease in CMS1 MSS tumors, leading to poor prognosis in this subtype. KRAS mutations are associated with adverse outcome in epithelial (CMS2/CMS3) MSS tumors.

Use of a fragment of glycoprotein G-2 produced in the baculovirus expression system for detecting herpes simplex virus type 2-specific antibodies

NARCIS (Netherlands)

Ikoma, M; Liljeqvist, JA; Glazenburg, KL; The, TH; Welling-Wester, S; Groen, J.

Fragments of glycoprotein G (gG-2(281-594His)), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1(t26-189His)), and glycoprotein D of HSV-1 (gD-1(1-313)), were expressed in the baculovirus expression system to develop an assay for the detection of

Dysfunction of bovine endogenous retrovirus K2 envelope glycoprotein is related to unsuccessful intracellular trafficking.

Science.gov (United States)

Nakaya, Yuki; Miyazawa, Takayuki

2014-06-01

Endogenous retroviruses (ERVs) are the remnants of retroviral infection of ancestral germ cells. Mutations introduced into ERVs halt the production of infectious agents, but their effects on the function of retroviral proteins are not fully understood. Retroviral envelope glycoproteins (Envs) are utilized in membrane fusion during viral entry, and we recently identified intact coding sequences for bovine endogenous retrovirus K1 (BERV-K1) and BERV-K2 Envs. Amino acid sequences of BERV-K1 Env (also called Fematrin-1) and BERV-K2 Env are similar, and both viruses are classified in the genus Betaretrovirus. While Fematrin-1 plays an important role in cell-to-cell fusion in bovine placenta, the BERV-K2 envelope gene is marginally expressed in vivo, and its recombinant Env protein is defective in membrane fusion due to inefficient cleavage of surface (SU) and transmembrane subunits. Here, we conducted chimeric analyses of Fematrin-1 and BERV-K2 Envs and revealed that defective maturation of BERV-K2 Env contributed to failed intracellular trafficking. Fluorescence microscopy and flow cytometric analysis suggested that in contrast to Fematrin-1 Env, BERV-K2 Env could not be transported from the endoplasmic reticulum to the trans-Golgi network, where cellular proteases required for processing retroviral Envs are localized. We also identified that one of the responsive regions of this phenomenon resided within a 65-amino-acid region of BERV-K2 SU. This is the first report to identify that retroviral Env SU is involved in the regulation of intracellular trafficking, and it may help to elucidate the maturation process of Fematrin-1 and other related Envs. Retroviruses utilize envelope glycoproteins (Envs) to enter host target cells. Mature retroviral Env is a heterodimer, which consists of surface (SU) and transmembrane (TM) subunits that are generated by the cleavage of an Env precursor protein in the trans-Golgi network. SU and TM mediate the recognition of the entry

Cooperative role of calnexin and TigA in Aspergillus oryzae glycoprotein folding.

Science.gov (United States)

Wang, Ning; Seko, Akira; Takeda, Yoichi; Kikuma, Takashi; Ito, Yukishige

2015-10-01

Calnexin (CNX), known as a lectin chaperone located in the endoplasmic reticulum (ER), specifically recognizes G1M9GN2-proteins and facilitates their proper folding with the assistance of ERp57 in mammalian cells. However, it has been left unidentified how CNX works in Aspergillus oryzae, which is a filamentous fungus widely exploited in biotechnology. In this study, we found that a protein disulfide isomerase homolog TigA can bind with A. oryzae CNX (AoCNX), which was revealed to specifically recognize monoglucosylated glycans, similarly to CNX derived from other species, and accelerate the folding of G1M9GN2-ribonuclease (RNase) in vitro. For refolding experiments, a homogeneous monoglucosylated high-mannose-type glycoprotein G1M9GN2-RNase was chemoenzymatically synthesized from G1M9GN-oxazoline and GN-RNase. Denatured G1M9GN2-RNase was refolded with highest efficiency in the presence of both soluble form of AoCNX and TigA. TigA contains two thioredoxin domains with CGHC motif, mutation analysis of which revealed that the one in N-terminal regions is involved in binding to AoCNX, while the other in catalyzing protein refolding. The results suggested that in glycoprotein folding process of A. oryzae, TigA plays a similar role as ERp57 in mammalian cells, as a partner protein of AoCNX. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The short mRNA isoform of the immunoglobulin superfamily, member 1 gene encodes an intracellular glycoprotein.

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Ying Wang

Full Text Available Mutations in the immunoglobulin superfamily, member 1 gene (IGSF1/Igsf1 cause an X-linked form of central hypothyroidism. The canonical form of IGSF1 is a transmembrane glycoprotein with 12 immunoglobulin (Ig loops. The protein is co-translationally cleaved into two sub-domains. The carboxyl-terminal domain (CTD, which contains the last 7 Ig loops, is trafficked to the plasma membrane. Most pathogenic mutations in IGSF1 map to the portion of the gene encoding the CTD. IGSF1/Igsf1 encodes a variety of transcripts. A little studied, but abundant splice variant encodes a truncated form of the protein, predicted to contain the first 2 Ig loops of the full-length IGSF1. The protein (hereafter referred to as IGSF1 isoform 2 or IGSF1-2 is likely retained in most individuals with IGSF1 mutations. Here, we characterized basic biochemical properties of the protein as a foray into understanding its potential function. IGSF1-2, like the IGSF1-CTD, is a glycoprotein. In both mouse and rat, the protein is N-glycosylated at a single asparagine residue in the first Ig loop. Contrary to earlier predictions, neither the murine nor rat IGSF1-2 is secreted from heterologous or homologous cells. In addition, neither protein associates with the plasma membrane. Rather, IGSF1-2 appears to be retained in the endoplasmic reticulum. Whether the protein plays intracellular functions or is trafficked through the secretory pathway under certain physiologic or pathophysiologic conditions has yet to be determined.

NR2E3 mutations in enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), clumped pigmentary retinal degeneration (CPRD), and retinitis pigmentosa (RP).

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Schorderet, Daniel F; Escher, Pascal

2009-11-01

NR2E3, also called photoreceptor-specific nuclear receptor (PNR), is a transcription factor of the nuclear hormone receptor superfamily whose expression is uniquely restricted to photoreceptors. There, its physiological activity is essential for proper rod and cone photoreceptor development and maintenance. Thirty-two different mutations in NR2E3 have been identified in either homozygous or compound heterozygous state in the recessively inherited enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), and clumped pigmentary retinal degeneration (CPRD). The clinical phenotype common to all these patients is night blindness, rudimental or absent rod function, and hyperfunction of the "blue" S-cones. A single p.G56R mutation is inherited in a dominant manner and causes retinitis pigmentosa (RP). We have established a new locus-specific database for NR2E3 (www.LOVD.nl/eye), containing all reported mutations, polymorphisms, and unclassified sequence variants, including novel ones. A high proportion of mutations are located in the evolutionarily-conserved DNA-binding domains (DBDs) and ligand-binding domains (LBDs) of NR2E3. Based on homology modeling of these NR2E3 domains, we propose a structural localization of mutated residues. The high variability of clinical phenotypes observed in patients affected by NR2E3-linked retinal degenerations may be caused by different disease mechanisms, including absence of DNA-binding, altered interactions with transcriptional coregulators, and differential activity of modifier genes.

Analysis of glycoprotein E-selectin ligANDs on human and mouse marrow cells enriched for hematopoietic stem/progenitor cells

KAUST Repository

Merzaban, Jasmeen S.

2011-06-09

Although well recognized that expression of E-selectin on marrow microvessels mediates osteotropism of hematopoietic stem/progenitor cells (HSPCs), our knowledge regarding the cognate E-selectin ligand(s) on HSPCs is incomplete. Flow cytometry using E-selectin-Ig chimera (E-Ig) shows that human marrow cells enriched for HSPCs (CD34+ cells) display greater E-selectin binding than those obtained from mouse (lin-/Sca-1+/c-kit+ [LSK] cells). To define the relevant glycoprotein E-selectin ligands, lysates from human CD34+ and KG1a cells and from mouse LSK cells were immunoprecipitated using E-Ig and resolved byWestern blot using E-Ig. In both human and mouse cells, E-selectin ligand reactivity was observed at ∼ 120- to 130-kDa region, which contained two E-selectin ligands, the P-selectin glycoprotein ligand- 1 glycoform "CLA," and CD43. Human, but not mouse, cells displayed a prominent ∼ 100-kDa band, exclusively comprising the CD44 glycoform "HCELL."E-Ig reactivity was most prominent on CLA in mouse cells and on HCELL in human cells. To further assess HCELL\\'s contribution to E-selectin adherence, complementary studies were performed to silence (via CD44 siRNA) or enforce its expression (via exoglycosylation). Under physiologic shear conditions, CD44/HCELL-silenced human cells showed striking decreases (> 50%) in E-selectin binding. Conversely, enforced HCELL expression of LSK cells profoundly increased E-selectin adherence, yielding > 3-fold more marrow homing in vivo. These data define the key glycoprotein E-selectin ligands of human and mouse HSPCs, unveiling critical species-intrinsic differences in both the identity and activity of these structures. © 2011 by The American Society of Hematology.

Role of BRAFV600E Mutation Analysis for Thyroid Nodules Classified as Indeterminate on Ultrasonography

International Nuclear Information System (INIS)

Nam, Sang Yu; Shin, Jung Hee; Han, Boo Kyung; Ko, Eun Young; Kang, Seok Seon; Hahn, Soo Yeon; Hwang, Ji Young; Nam, Mee Young; Kim, Jong Won; Chung, Jae Hoon

2010-01-01

We aimed to evaluate a possible role for BRAFV600E mutation analysis of aspiration specimens in the work up of thyroid nodules classified as indeterminate on US. A total of 122 nodules from 122 patients were prospectively classified as indeterminate nodules based on US findings. US-guided fine needle aspiration (FNA) was done for all 122 nodules. The presence of a BRAFV600E mutation in FNA specimens was determined by allele-specific PCR. US-indeterminate nodules were confirmed as malignant in 20.5% (25/122) of cases and benign in 76.2% (93/122) after FNA or surgery. A few (3.3% (4/122), remained indeterminate. A BRAFV600E mutation was identified in 14.8% (18/122) of US indeterminate nodules. Of those 18 nodules, three were benign and 13 were malignant after the initial FNA. One (0.8%, 1/122) with an initially benign cytology and a BRAFV600E mutation was confirmed to be malignant after surgery. The remaining two benign nodules with a mutation were not followed-up. All 9 initial FNA-nondiagnostic nodules were mutation negative but 2 (11.8%) of 17 indeterminate nodules on initial FNAs were mutation positive. BRAFV600E mutation analysis prevents false negative cytology for only 0.8% of cases and reduces ambiguous diagnoses for 1.6% of all US-indeterminate thyroid nodules. Therefore, adding BRAFV600E mutation analysis to FNA for US-indeterminate nodules is of limited usefulness

Synaptic vesicle glycoprotein 2C (SV2C) modulates dopamine release and is disrupted in Parkinson disease.

Science.gov (United States)

Dunn, Amy R; Stout, Kristen A; Ozawa, Minagi; Lohr, Kelly M; Hoffman, Carlie A; Bernstein, Alison I; Li, Yingjie; Wang, Minzheng; Sgobio, Carmelo; Sastry, Namratha; Cai, Huaibin; Caudle, W Michael; Miller, Gary W

2017-03-14

Members of the synaptic vesicle glycoprotein 2 (SV2) family of proteins are involved in synaptic function throughout the brain. The ubiquitously expressed SV2A has been widely implicated in epilepsy, although SV2C with its restricted basal ganglia distribution is poorly characterized. SV2C is emerging as a potentially relevant protein in Parkinson disease (PD), because it is a genetic modifier of sensitivity to l-DOPA and of nicotine neuroprotection in PD. Here we identify SV2C as a mediator of dopamine homeostasis and report that disrupted expression of SV2C within the basal ganglia is a pathological feature of PD. Genetic deletion of SV2C leads to reduced dopamine release in the dorsal striatum as measured by fast-scan cyclic voltammetry, reduced striatal dopamine content, disrupted α-synuclein expression, deficits in motor function, and alterations in neurochemical effects of nicotine. Furthermore, SV2C expression is dramatically altered in postmortem brain tissue from PD cases but not in Alzheimer disease, progressive supranuclear palsy, or multiple system atrophy. This disruption was paralleled in mice overexpressing mutated α-synuclein. These data establish SV2C as a mediator of dopamine neuron function and suggest that SV2C disruption is a unique feature of PD that likely contributes to dopaminergic dysfunction.

Epitope Dampening Monotypic Measles Virus Hemagglutinin Glycoprotein Results in Resistance to Cocktail of Monoclonal Antibodies

Science.gov (United States)

Lech, Patrycja J.; Tobin, Gregory J.; Bushnell, Ruth; Gutschenritter, Emily; Pham, Linh D.; Nace, Rebecca; Verhoeyen, Els; Cosset, François-Loïc; Muller, Claude P.; Russell, Stephen J.; Nara, Peter L.

2013-01-01

The measles virus (MV) is serologically monotypic. Life-long immunity is conferred by a single attack of measles or following vaccination with the MV vaccine. This is contrary to viruses such as influenza, which readily develop resistance to the immune system and recur. A better understanding of factors that restrain MV to one serotype may allow us to predict if MV will remain monotypic in the future and influence the design of novel MV vaccines and therapeutics. MV hemagglutinin (H) glycoprotein, binds to cellular receptors and subsequently triggers the fusion (F) glycoprotein to fuse the virus into the cell. H is also the major target for neutralizing antibodies. To explore if MV remains monotypic due to a lack of plasticity of the H glycoprotein, we used the technology of Immune Dampening to generate viruses with rationally designed N-linked glycosylation sites and mutations in different epitopes and screened for viruses that escaped monoclonal antibodies (mAbs). We then combined rationally designed mutations with naturally selected mutations to generate a virus resistant to a cocktail of neutralizing mAbs targeting four different epitopes simultaneously. Two epitopes were protected by engineered N-linked glycosylations and two epitopes acquired escape mutations via two consecutive rounds of artificial selection in the presence of mAbs. Three of these epitopes were targeted by mAbs known to interfere with receptor binding. Results demonstrate that, within the epitopes analyzed, H can tolerate mutations in different residues and additional N-linked glycosylations to escape mAbs. Understanding the degree of change that H can tolerate is important as we follow its evolution in a host whose immunity is vaccine induced by genotype A strains instead of multiple genetically distinct wild-type MVs. PMID:23300970

Restoration of glycoprotein Erns dimerization via pseudoreversion partially restores virulence of classical swine fever virus.

Science.gov (United States)

Tucakov, Anna Katharina; Yavuz, Sabine; Schürmann, Eva-Maria; Mischler, Manjula; Klingebeil, Anne; Meyers, Gregor

2018-01-01

The classical swine fever virus (CSFV) represents one of the most important pathogens of swine. The CSFV glycoprotein E rns is an essential structural protein and an important virulence factor. The latter is dependent on the RNase activity of this envelope protein and, most likely, its secretion from the infected cell. A further important feature with regard to its function as a virulence factor is the formation of disulfide-linked E rns homodimers that are found in virus-infected cells and virions. Mutant CSFV lacking cysteine (Cys) 171, the residue responsible for intermolecular disulfide bond formation, were found to be attenuated in pigs (Tews BA, Schürmann EM, Meyers G. J Virol 2009;83:4823-4834). In the course of an animal experiment with such a dimerization-negative CSFV mutant, viruses were reisolated from pigs that contained a mutation of serine (Ser) 209 to Cys. This mutation restored the ability to form disulphide-linked E rns homodimers. In transient expression studies E rns mutants carrying the S209C change were found to form homodimers with about wt efficiency. Also the secretion level of the mutated proteins was equivalent to that of wt E rns . Virus mutants containing the Cys171Ser/Ser209Cys configuration exhibited wt growth rates and increased virulence when compared with the Cys171Ser mutant. These results provide further support for the connection between CSFV virulence and E rns dimerization.

Preparation of 131I-asialo-α1-acid glycoprotein

International Nuclear Information System (INIS)

Rijk, P.P. van

1975-01-01

α 1 -Acid glycoprotein (orosomucoid) was prepared from a byproduct of the ethanol plasma fractionation by means of ion-exchange procedures. Immunoelectrophoresis suggested a high degree of purity; the purified protein contained 13.5% sialic acid and 17.8% hexose. The α 1 -acid glycoprotein was modified by removal of sialic acid with neurominidase (E.C. 3.2.1.18) followed by iodination with 131 I. The purpose of the preparation, its potential use as a pharmacon for liver-function studies in nuclear medicine, is the subject of further study

Global identification of prokaryotic glycoproteins based on an Escherichia coli proteome microarray.

Directory of Open Access Journals (Sweden)

Zong-Xiu Wang

Full Text Available Glycosylation is one of the most abundant protein posttranslational modifications. Protein glycosylation plays important roles not only in eukaryotes but also in prokaryotes. To further understand the roles of protein glycosylation in prokaryotes, we developed a lectin binding assay to screen glycoproteins on an Escherichia coli proteome microarray containing 4,256 affinity-purified E.coli proteins. Twenty-three E.coli proteins that bound Wheat-Germ Agglutinin (WGA were identified. PANTHER protein classification analysis showed that these glycoprotein candidates were highly enriched in metabolic process and catalytic activity classes. One sub-network centered on deoxyribonuclease I (sbcB was identified. Bioinformatics analysis suggests that prokaryotic protein glycosylation may play roles in nucleotide and nucleic acid metabolism. Fifteen of the 23 glycoprotein candidates were validated by lectin (WGA staining, thereby increasing the number of validated E. coli glycoproteins from 3 to 18. By cataloguing glycoproteins in E.coli, our study greatly extends our understanding of protein glycosylation in prokaryotes.

Mutational analysis of the EMCV 2A protein identifies a nuclear localization signal and an eIF4E binding site

International Nuclear Information System (INIS)

Groppo, Rachel; Brown, Bradley A.; Palmenberg, Ann C.

2011-01-01

Cardioviruses have a unique 2A protein (143 aa). During genome translation, the encephalomyocarditis virus (EMCV) 2A is released through a ribosome skipping event mitigated through C-terminal 2A sequences and by subsequent N-terminal reaction with viral 3C pro . Although viral replication is cytoplasmic, mature 2A accumulates in nucleoli shortly after infection. Some protein also transiently associates with cytoplasmic 40S ribosomal subunits, an activity contributing to inhibition of cellular cap-dependent translation. Cardiovirus sequences predict an eIF4E binding site (aa 126-134) and a nuclear localization signal (NLS, aa 91-102), within 2A, both of which are functional during EMCV infection. Point mutations preventing eIF4E:2A interactions gave small-plaque phenotype viruses, but still inhibited cellular cap-dependent translation. Deletions within the NLS motif relocalized 2A to the cytoplasm and abrogated the inhibition of cap-dependent translation. A fusion protein linking the 2A NLS to eGFP was sufficient to redirect the reporter to the nucleus but not into nucleoli.

The PB2-K627E mutation attenuates H3N2 swine influenza virus in cultured cells and in mice.

Science.gov (United States)

Gong, Xiao-Qian; Ruan, Bao-Yang; Liu, Xiao-Min; Zhang, Peng; Wang, Xiu-Hui; Wang, Qi; Shan, Tong-Ling; Tong, Wu; Zhou, Yan-Jun; Li, Guo-Xin; Zheng, Hao; Tong, Guang-Zhi; Yu, Hai

2018-04-01

PB2-627K is an important amino acid that determines the virulence of some influenza A viruses. However, it has not been experimentally investigated in the H3N2 swine influenza virus. To explore the potential role of PB2-K627E substitution in H3N2 swine influenza virus, the growth properties and pathogenicity between H3N2 swine influenza virus and its PB2-K627E mutant were compared. For the first time, our results showed that PB2-K627E mutation attenuates H3N2 swine influenza virus in mammalian cells and in mice, suggesting that PB2-627K is required for viral replication and pathogenicity of H3N2 swine influenza virus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular analysis of formaldehyde-induced mutations in human lymphoblasts and E. coli

International Nuclear Information System (INIS)

Crosby, R.M.; Richardson, K.K.; Craft, T.R.; Benforado, K.B.; Liber, H.L.; Skopek, T.R.

1988-01-01

The molecular nature of formaldehyde (HCHO)-induced mutations was studied in both human lymphoblasts and E. coli. Thirty HPRT - human lymphoblast colonies induced by eight repetitive 150 μM HCHO treatments were characterized by Southern blot analysis. Fourteen of these mutants (47%) had visible deletions of some or all of the X-linked HPRT bands, indicating that HCHO can induce large losses of DNA in human lymphoblasts. In E. coli., DNA alterations induced by HCHO were characterized with use of the xanthine guanine phosphoribosyl transferase (gpt) gene as the genetic target. Exposure of E. coli to 4 mM HCHO for 1 hr induced large insertions (41%), large deletions (18%), and point mutations (41%). Dideoxy DNA sequencing revealed that most of the point mutations were transversions at GC base pairs. In contrast, exposure of E. coli to 40 mM HCHO for 1 hr produced 92% point mutations, 62% of which were transitions at a single AT base pair in the gene. Therefore, HCHO is capable of producing different genetic alterations in E. coli at different concentrations, suggesting fundamental differences in the mutagenic mechanisms operating at the two concentrations used. Naked pSV2gpt plasmid DNA was exposed to 3.3 or 10 mM HCHO and transformed into E. coli. Most of the resulting mutations were frameshifts, again suggesting a different mutagenic mechanism

PMS2 mutations in childhood cancer.

Science.gov (United States)

De Vos, Michel; Hayward, Bruce E; Charlton, Ruth; Taylor, Graham R; Glaser, Adam W; Picton, Susan; Cole, Trevor R; Maher, Eamonn R; McKeown, Carole M E; Mann, Jill R; Yates, John R; Baralle, Diana; Rankin, Julia; Bonthron, David T; Sheridan, Eamonn

2006-03-01

Until recently, the PMS2 DNA mismatch repair gene has only rarely been implicated as a cancer susceptibility locus. New studies have shown, however, that earlier analyses of this gene have had technical limitations and also that the genetic behavior of mutant PMS2 alleles is unusual, in that, unlike MLH1 or MSH2 mutations, PMS2 mutations show low heterozygote penetrance. As a result, a dominantly inherited cancer predisposition has not been a feature reported in families with PMS2 mutations. Such families have instead been ascertained through childhood-onset cancers in homozygotes or through apparently sporadic colorectal cancer in heterozygotes. We present further information on the phenotype associated with homozygous PMS2 deficiency in 13 patients from six families of Pakistani origin living in the United Kingdom. This syndrome is characterized by café-au-lait skin pigmentation and a characteristic tumor spectrum, including leukemias, lymphomas, cerebral malignancies (such as supratentorial primitive neuroectodermal tumors, astrocytomas, and glioblastomas), and colorectal neoplasia with an onset in early adult life. We present evidence for a founder effect in five families, all of which carried the same R802-->X mutation (i.e., arginine-802 to stop) in PMS2. This cancer syndrome can be mistaken for neurofibromatosis type 1, with important management implications including the risk of the disorder occurring in siblings and the likelihood of tumor development in affected individuals.

A Comprehensive Strategy for Accurate Mutation Detection of the Highly Homologous PMS2.

Science.gov (United States)

Li, Jianli; Dai, Hongzheng; Feng, Yanming; Tang, Jia; Chen, Stella; Tian, Xia; Gorman, Elizabeth; Schmitt, Eric S; Hansen, Terah A A; Wang, Jing; Plon, Sharon E; Zhang, Victor Wei; Wong, Lee-Jun C

2015-09-01

Germline mutations in the DNA mismatch repair gene PMS2 underlie the cancer susceptibility syndrome, Lynch syndrome. However, accurate molecular testing of PMS2 is complicated by a large number of highly homologous sequences. To establish a comprehensive approach for mutation detection of PMS2, we have designed a strategy combining targeted capture next-generation sequencing (NGS), multiplex ligation-dependent probe amplification, and long-range PCR followed by NGS to simultaneously detect point mutations and copy number changes of PMS2. Exonic deletions (E2 to E9, E5 to E9, E8, E10, E14, and E1 to E15), duplications (E11 to E12), and a nonsense mutation, p.S22*, were identified. Traditional multiplex ligation-dependent probe amplification and Sanger sequencing approaches cannot differentiate the origin of the exonic deletions in the 3' region when PMS2 and PMS2CL share identical sequences as a result of gene conversion. Our approach allows unambiguous identification of mutations in the active gene with a straightforward long-range-PCR/NGS method. Breakpoint analysis of multiple samples revealed that recurrent exon 14 deletions are mediated by homologous Alu sequences. Our comprehensive approach provides a reliable tool for accurate molecular analysis of genes containing multiple copies of highly homologous sequences and should improve PMS2 molecular analysis for patients with Lynch syndrome. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Rhodocytin (aggretin) activates platelets lacking alpha(2)beta(1) integrin, glycoprotein VI, and the ligand-binding domain of glycoprotein Ibalpha

DEFF Research Database (Denmark)

Bergmeier, W; Bouvard, D; Eble, J A

2001-01-01

Although alpha(2)beta(1) integrin (glycoprotein Ia/IIa) has been established as a platelet collagen receptor, its role in collagen-induced platelet activation has been controversial. Recently, it has been demonstrated that rhodocytin (also termed aggretin), a snake venom toxin purified from the v...

Dosage-dependent copy number gains in E2f1 and E2f3 drive hepatocellular carcinoma.

Science.gov (United States)

Kent, Lindsey N; Bae, Sooin; Tsai, Shih-Yin; Tang, Xing; Srivastava, Arunima; Koivisto, Christopher; Martin, Chelsea K; Ridolfi, Elisa; Miller, Grace C; Zorko, Sarah M; Plevris, Emilia; Hadjiyannis, Yannis; Perez, Miguel; Nolan, Eric; Kladney, Raleigh; Westendorp, Bart; de Bruin, Alain; Fernandez, Soledad; Rosol, Thomas J; Pohar, Kamal S; Pipas, James M; Leone, Gustavo

2017-03-01

Disruption of the retinoblastoma (RB) tumor suppressor pathway, either through genetic mutation of upstream regulatory components or mutation of RB1 itself, is believed to be a required event in cancer. However, genetic alterations in the RB-regulated E2F family of transcription factors are infrequent, casting doubt on a direct role for E2Fs in driving cancer. In this work, a mutation analysis of human cancer revealed subtle but impactful copy number gains in E2F1 and E2F3 in hepatocellular carcinoma (HCC). Using a series of loss- and gain-of-function alleles to dial E2F transcriptional output, we have shown that copy number gains in E2f1 or E2f3b resulted in dosage-dependent spontaneous HCC in mice without the involvement of additional organs. Conversely, germ-line loss of E2f1 or E2f3b, but not E2f3a, protected mice against HCC. Combinatorial mapping of chromatin occupancy and transcriptome profiling identified an E2F1- and E2F3B-driven transcriptional program that was associated with development and progression of HCC. These findings demonstrate a direct and cell-autonomous role for E2F activators in human cancer.

Identification of broadly reactive epitopes targeting major glycoproteins of Herpes simplex virus (HSV) 1 and 2 - An immunoinformatics analysis.

Science.gov (United States)

Chauhan, Varun; Goyal, Kapil; Singh, Mini P

2018-07-01

Infections due to both HSV-1 and HSV-2 constitute an enormous health burden worldwide. Development of vaccine against herpes infections is a WHO supported public health priority. The viral glycoproteins have always been the major hotspots for vaccine designing. The present study was aimed to identify the conserved T and B cell epitopes in the major glycoproteins of both HSV-1 and HSV-2 via rigorous computational approaches. Identification of promiscuous T cell epitopes is of utmost importance in vaccine designing as such epitopes are capable of binding to several allelic forms of HLA and could generate effective immune response in the host. The criteria designed for identification of T and B cell epitopes was that it should be conserved in both HSV-1 and 2, promiscuous, have high affinity towards HLA alleles, should be located on the surface of glycoproteins and not be present in the glycosylation sites. This study led to the identification of 17 HLA Class II and 26 HLA Class I T cell epitopes, 9 linear and some conformational B cell epitopes. The identified T cell epitopes were further subjected to molecular docking analysis to analyze their binding patterns. Altogether we have identified 4 most promising regions in glycoproteins (2-gB, 1-gD, 1-gH) of HSV-1 and 2 which are promiscuous to HLA Class II alleles and have overlapping HLA Class I and B cell epitopes, which could be very useful in generating both arms of immune response in the host i.e. adaptive as well as humoral immunity. Further the authors propose the cross-validation of the identified epitopes in experimental settings for confirming their immunogenicity to support the present findings. Copyright © 2018 Elsevier B.V. All rights reserved.

Hepatitis C Virus E1 and E2 Proteins Used as Separate Immunogens Induce Neutralizing Antibodies with Additive Properties.

Directory of Open Access Journals (Sweden)

Elodie Beaumont

Full Text Available Various strategies involving the use of hepatitis C virus (HCV E1 and E2 envelope glycoproteins as immunogens have been developed for prophylactic vaccination against HCV. However, the ideal mode of processing and presenting these immunogens for effective vaccination has yet to be determined. We used our recently described vaccine candidate based on full-length HCV E1 or E2 glycoproteins fused to the heterologous hepatitis B virus S envelope protein to compare the use of the E1 and E2 proteins as separate immunogens with their use as the E1E2 heterodimer, in terms of immunogenetic potential and the capacity to induce neutralizing antibodies. The specific anti-E1 and anti-E2 antibody responses induced in animals immunized with vaccine particles harboring the heterodimer were profoundly impaired with respect to those in animals immunized with particles harboring E1 and E2 separately. Moreover, the anti-E1 and anti-E2 antibodies had additive neutralizing properties that increase the cross-neutralization of heterologous strains of various HCV genotypes, highlighting the importance of including both E1 and E2 in the vaccine for an effective vaccination strategy. Our study has important implications for the optimization of HCV vaccination strategies based on HCV envelope proteins, regardless of the platform used to present these proteins to the immune system.

Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus

DEFF Research Database (Denmark)

Giang, Erick; Dorner, Marcus; Prentoe, Jannick C

2012-01-01

, and an effective vaccine should target conserved T- and B-cell epitopes of the virus. Conserved B-cell epitopes overlapping the CD81 receptor-binding site (CD81bs) on the E2 viral envelope glycoprotein have been reported previously and provide promising vaccine targets. In this study, we isolated 73 human m......Abs recognizing five distinct antigenic regions on the virus envelope glycoprotein complex E1E2 from an HCV-immune phage-display antibody library by using an exhaustive-panning strategy. Many of these mAbs were broadly neutralizing. In particular, the mAb AR4A, recognizing a discontinuous epitope outside the CD81......bs on the E1E2 complex, has an exceptionally broad neutralizing activity toward diverse HCV genotypes and protects against heterologous HCV challenge in a small animal model. The mAb panel will be useful for the design and development of vaccine candidates to elicit broadly neutralizing antibodies...

Clinical significance of the BRAFV600E mutation in Asian patients with colorectal cancer.

Science.gov (United States)

Cheng, Hou-Hsuan; Lin, Jen-Kou; Chen, Wei-Shone; Jiang, Jeng-Kai; Yang, Shung-Haur; Chang, Shih-Ching

2018-06-04

To investigate the clinicopathological features and prognostic significance of the BRAFV600E mutation in Asian patients with colorectal cancer. We retrospectively reviewed the medical records of 1969 patients with colorectal cancer admitted to Taipei Veterans General Hospital for surgical treatment between 2000 and 2013. The measured endpoint was overall survival after surgery. The prognostic value of the BRAFV600E mutation was analyzed using the log-rank test and Cox regression analysis. The BRAFV600E mutation was detected in 106 (5.4%) patients and associated with female gender, abnormal cancer antigen (CA)19-9 at diagnosis, microsatellite status, right-sided primary tumors, mucinous histology, poor differentiation, and lymphovascular invasion. Metastatic patterns were more common in non-regional lymph node metastasis (20.8 vs. 7.4%, p = 0.06) and peritoneal seeding (41. vs. 21.2%, p = 0.04). Mutations were not prognostic in the overall survival of the entire study group but only in specific patients: age < 65, normal carcinoembryonic antigen at diagnosis, and stage IV disease. The BRAFV600E mutation was associated with distinct clinicopathological features and metastatic patterns. The overall survival rate was lower in selected colorectal patients with the BRAFV600E mutation.

Analysis of the N-glycosylation of the serum glycoproteins defined by Con A, PHA-E, RCA1 and WGA in Chinese patients with gastrointestinal diseases.

Science.gov (United States)

Zhang, J; Chen, Y; Dai, X; Wang, S

1996-03-01

Glycoproteins from tumor cells isolated by Con A, PHA-E and RCA1, were coupled to horse radish peroxidase and then used as reporters to evaluate the oligosaccharides change on serum glycoproteins in digestive tract diseases and individual healthy persons. A value 2 standard deviation above the mean of the healthy person group was considered positive. The results indicated that the positive rates of the oligosaccharides bound with Con A, PHA-E and RCA1 were 51% (61/119), 70.6% (84/119), and 76.4% (91/119) in patients with gastric cancer; 53.3% (16/30), 46.7% (14/30) and 66.7% (20/30) in esophageal cancers; 28.5% (15/49), 49.0% (24/49) and 46.9% (23/49) in colorectal cancer; 78.1% (25/32), 81.3% (26/32) and 31.3% (10/32) in gallbladder tumors; 60.4% (29/48), 54.1% (26/48) and 39.5% (19/48) in hepatocellular cancer. The positive rates among the patients with benign diseases were also found to be 12.7% (16/126), 15.5% (20/126) and 26.2% (33/126). However, the expression of the oligosaccharide moieties recognized by WGA on the glycoprotein bound with Con A, was significantly lower in the serum of patients with tumors than in those with benign disease and in healthy individuals (P < 0.01, P < 0.01).

MPL mutation profile in JAK2 mutation-negative patients with myeloproliferative disorders.

Science.gov (United States)

Ma, Wanlong; Zhang, Xi; Wang, Xiuqiang; Zhang, Zhong; Yeh, Chen-Hsiung; Uyeji, Jennifer; Albitar, Maher

2011-03-01

Mutations in the thrombopoietin receptor gene (myeloproliferative leukemia, MPL) have been reported in patients with JAK2 V617F-negative chronic myeloproliferative disorders (MPDs). We evaluated the prevalence of MPL mutations relative to JAK2 mutations in patients with suspected MPDs. A total of 2790 patient samples submitted for JAK2 mutation analysis were tested using real-time polymerase chain reaction and bidirectional sequencing of plasma RNA. JAK2 V617F-negative samples were tested for JAK2 exons 12 to 14 mutations, and those with negative results were then tested for mutations in MPL exons 10 and 11. Of the 2790 patients, 529 (18.96%) had V617F, 12 (0.43%) had small insertions or deletions in exon 12, and 7 (0.25%) had other JAK2 mutations in exons 12 to 14. Of the 2242 JAK2 mutation-negative patients, 68 (3.03%) had MPL mutations. W515L was the predominant MPL mutation (n=46; 68%), and 10 (15%) patients had other W515 variants. The remaining MPL mutations (n=12, 17%) were detected at other locations in exons 10 and 11 and included 3 insertion/deletion mutations. The S505N mutation, associated with familial MPD, was detected in 3 patients. Overall, for every 100 V617F mutations in patients with suspected MPDs, there were 12.9 MPL mutations, 2.3 JAK2 exon 12 mutations, and 1.3 JAK2 exons 13 to 14 mutations. These findings suggest that MPL mutation screening should be performed before JAK2 exons 12 to 14 testing in JAK2 V617F-negative patients with suspected MPDs.

Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

International Nuclear Information System (INIS)

Wang, Jimin; Li, Yue; Modis, Yorgo

2014-01-01

The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: • Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. • Atomic models of the E1 and E2 membrane anchors were generated in silico. • A “snorkeling” arginine completes the short helical hairpin in the E2 membrane anchor. • Roles in pH sensing and E1–E2 disulfide bond formation are proposed for E1 residues. • Implications for E1 ectodomain structure and disulfide bonding pattern are discussed

Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

Energy Technology Data Exchange (ETDEWEB)

Wang, Jimin, E-mail: jimin.wang@yale.edu; Li, Yue; Modis, Yorgo, E-mail: yorgo.modis@yale.edu

2014-04-15

The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: • Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. • Atomic models of the E1 and E2 membrane anchors were generated in silico. • A “snorkeling” arginine completes the short helical hairpin in the E2 membrane anchor. • Roles in pH sensing and E1–E2 disulfide bond formation are proposed for E1 residues. • Implications for E1 ectodomain structure and disulfide bonding pattern are discussed.

Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs.

Science.gov (United States)

Jiang, Xiaohong; Dalebout, Tim J; Bredenbeek, Peter J; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S; Lukashevich, Igor S

2011-02-01

Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. Copyright © 2010 Elsevier Ltd. All rights reserved.

Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs

Science.gov (United States)

Jiang, Xiaohong; Dalebout, Tim J.; Bredenbeek, Peter J.; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S.; Lukashevich, Igor S.

2010-01-01

Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV GP1 and GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and –GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF and LASV GP proteins in infected cells. YF17D/LASV-GP1&GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1&GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. PMID:21145373

Intracellular localization of hydroxyproline-rich glycoprotein biosynthesis

International Nuclear Information System (INIS)

Robinson, D.G.; Andreae, M.; Glas, A.R.; Sauer, A.

1984-01-01

The structural proteins of plant cell walls are glycoproteins characterized by O-glucosidic linkages to hydroxyproline or serine. Proline, not hydroxyproline, is the translatable amino acid in hydroxyproline-rich glycoproteins (HRGP). Hydroxylation and arabinosylation of proline are sequential, post-translational events. Because of this, there is no a priori reason for expecting HRGP synthesis to follow the well-established route for secretory and plasma membrane (PM) glycoproteins, i.e., from endoplasmic reticulum (ER) via the Golgi apparatus (GA) to the PM. In this paper, two plausible alternatives for HRGO secretion are examined. Because a feature of the majority of dicotyledons is overlapping GA and PM regions in sucrose density gradients, the authors have used two monocotyledonous systems to determine the distribution of HRGP and enzyme activity

Defining glycoprotein cancer biomarkers by MS in conjunction with glycoprotein enrichment.

Science.gov (United States)

Song, Ehwang; Mechref, Yehia

2015-01-01

Protein glycosylation is an important and common post-translational modification. More than 50% of human proteins are believed to be glycosylated to modulate the functionality of proteins. Aberrant glycosylation has been correlated to several diseases, such as inflammatory skin diseases, diabetes mellitus, cardiovascular disorders, rheumatoid arthritis, Alzheimer's and prion diseases, and cancer. Many approved cancer biomarkers are glycoproteins which are not highly abundant proteins. Therefore, effective qualitative and quantitative assessment of glycoproteins entails enrichment methods. This chapter summarizes glycoprotein enrichment methods, including lectin affinity, immunoaffinity, hydrazide chemistry, hydrophilic interaction liquid chromatography, and click chemistry. The use of these enrichment approaches in assessing the qualitative and quantitative changes of glycoproteins in different types of cancers are presented and discussed. This chapter highlights the importance of glycoprotein enrichment techniques for the identification and characterization of new reliable cancer biomarkers.

Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

Science.gov (United States)

Wang, Jimin; Li, Yue; Modis, Yorgo

2014-01-01

The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. PMID:24725935

Urinary excretion of beta 2-glycoprotein-1 (apolipoprotein H) and other markers of tubular malfunction in "non-tubular" renal disease.

Science.gov (United States)

Flynn, F V; Lapsley, M; Sansom, P A; Cohen, S L

1992-07-01

To determine whether urinary beta 2-glycoprotein-1 assays can provide improved discrimination between chronic renal diseases which are primarily of tubular or glomerular origin. Urinary beta 2-glycoprotein-1, retinol-binding protein, alpha 1-microglobulin, beta 2-microglobulin, N-acetyl-beta-D-glucosa-minidase and albumin were measured in 51 patients with primary glomerular disease, 23 with obstructive nephropathy, and 15 with polycystic kidney disease, and expressed per mmol of creatinine. Plasma beta 2-glycoprotein-1 was assayed in 52 patients and plasma creatinine in all 89. The findings were compared between the diagnostic groups and with previously published data relating to primary tubular disorders. All 31 patients with plasma creatinine greater than 200 mumol/l excreted increased amounts of beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin, and 29 had increased N-acetyl-beta-D-glucosaminidase; the quantities were generally similar to those found in comparable patients with primary tubular pathology. Among 58 with plasma creatinine concentrations under 200 mumol/l, increases in beta 2-glycoprotein-1, retinol-binding protein, and alpha 1-microglobulin excretion were less common and much smaller, especially in those with obstructive nephropathy and polycystic disease. The ratios of the excretion of albumin to the other proteins provided the clearest discrimination between the patients with glomerular or tubular malfunction, but an area of overlap was present which embraced those with obstructive nephropathy and polycystic disease. Increased excretion of beta 2-glycoprotein-1 due to a raised plasma concentration or diminution of tubular reabsorption, or both, is common in all the forms of renal disease investigated, and both plasma creatinine and urinary albumin must be taken into account when interpreting results. Ratios of urinary albumin: beta 2-glycoprotein-1 greater than 1000 are highly suggestive of primary glomerular disease and

Characterization of cancer-associated missense mutations in MDM2

OpenAIRE

Chauhan, Krishna M.; Ramakrishnan, Gopalakrishnan; Kollareddy, Madhusudhan; Martinez, Luis A.

2015-01-01

MDM2 is an E3 ubiquitin ligase that binds the N-terminus of p53 and promotes its ubiquitin-dependent degradation. Elevated levels of MDM2 due to overexpression or gene amplification can contribute to tumor development by suppressing p53 activity. Since MDM2 is an oncogene, we explored the possibility that other genetic lesions, namely missense mutations, might alter its activities. We selected mutations in MDM2 that reside in one of the 4 key regions of the protein: p53 binding domain, acidic...

BRAF V600E mutational status in bile duct adenomas and hamartomas.

Science.gov (United States)

Pujals, Anaïs; Bioulac-Sage, Paulette; Castain, Claire; Charpy, Cécile; Zafrani, Elie Serge; Calderaro, Julien

2015-10-01

Bile duct adenomas (BDA) and bile duct hamartomas (BDH) are benign bile duct lesions considered neoplastic or secondary to ductal plate malformation, respectively. We have reported previously a high prevalence of BRAF V600E mutations detected by allele-specific polymerase chain reaction assay in BDA, and suggested that BDA may be precursors to a subset of intrahepatic cholangiocarcinomas harbouring V600E mutations. The aim of the present study was to assess the existence of BRAF V600E mutations, using immunohistochemical methods, in additional BDA as well as in BDH. Fifteen BDA and 35 BDH were retrieved from the archives of the pathology departments of two French university hospitals. All cases were reviewed by two pathologists specialized in liver diseases. BRAF V600E mutational status was investigated by immunohistochemistry. Mutated BRAF mutant protein was detected in 53% of the BDA and in none of the cases of BDH. Our findings suggest that BDA and BDH are different processes, and that BDA represent true benign neoplasms. They also support the hypothesis that mutated BDA might precede the development of the subset of intrahepatic cholangiocarcinomas harbouring BRAF V600E mutations. © 2015 John Wiley & Sons Ltd.

Influence of preirradiation history of E. coli WP2 cells on the residual fixation of mutations in rpsL. (strA) locus

Energy Technology Data Exchange (ETDEWEB)

Filippov, V D

1986-07-01

The values of residual fixation of strA mutations in E.coli culture, irradiated by UV-light (6.8 J/m/sup 2/) in different physiological states and conforming to different in depth strA mutation frequency decrease in postirradiation incubation under conditions unfavourable for protein synthesis are determined. By residual fixation one should mean accumulation of strA mutations stable to antimutagenous effect of photoreactivating light in cell population incubated in buffer after UV radiation. It is established that residual fixation is small in cultures, conforming to deep decrease, and is a factor (about 40% of strA mutations is fixed) in a culture, conforming to moderate decrease (about 60% of strA mutations disappears) of mutation frequency in incubation under conditions unfavourable for protein synthesis. The conclusion is made that the depth of strA mutation frequency decrease, taking place under the influence of mfd system, depends on the level of residual fixation of this mutations. It is supposed that residual fixation is caused by rpsL (strA) locus introduction in replication cycle initiated after radiation.

IgA antibodies against β2 glycoprotein I in hemodialysis patients are an independent risk factor for mortality.

Science.gov (United States)

Serrano, Antonio; García, Florencio; Serrano, Manuel; Ramírez, Elisa; Alfaro, F Javier; Lora, David; de la Cámara, Agustín Gómez; Paz-Artal, Estela; Praga, Manuel; Morales, Jose M

2012-06-01

Cardiovascular complications are the most important cause of death in patients on dialysis with end-stage renal disease. Antibodies reacting with β-glycoprotein I seem to play a pathogenic role in antiphospholipid syndrome and stroke and are involved in the origin of atherosclerosis. Here we evaluated the presence of anticardiolipin and anti-β-glycoprotein I antibodies together with other vascular risk factors and their relationship with mortality and cardiovascular morbidity in a cohort of 124 hemodialysis patients prospectively followed for 2 years. Of these, 41 patients were significantly positive for IgA anti-β-glycoprotein I, and the remaining had normal values. At 24 months, overall and cardiovascular mortality and thrombotic events were all significantly higher in patients with high anti-β-glycoprotein I antibodies. Multivariate analysis using Cox regression modeling found that age, hypoalbuminemia, use of dialysis catheters, and IgA β-glycoprotein I antibodies were independent risk factors for death. Thus, IgA antibodies to β-glycoprotein I are detrimental to the clinical outcome of hemodialysis patients.

Profiling of Concanavalin A-Binding Glycoproteins in Human Hepatic Stellate Cells Activated with Transforming Growth Factor-β1

Directory of Open Access Journals (Sweden)

Yannan Qin

2014-11-01

Full Text Available Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA was increased in human hepatic stellate cells (HSCs following activation by transforming growth factor-β1 (TGF-β1; however, little is known about the ConA-binding glycoproteins (CBGs of HSCs. In this study, we employed a targeted glycoproteomics approach using lectin-magnetic particle conjugate-based liquid chromatography-tandem mass spectrometry to compare CBG profiles between LX-2 HSCs with and without activation by TGF-β1, with the aim of discovering novel CBGs and determining their possible roles in activated HSCs. A total of 54 and 77 proteins were identified in the quiescent and activated LX-2 cells, respectively. Of the proteins identified, 14.3% were glycoproteins and 73.3% were novel potential glycoproteins. Molecules involved in protein processing in the endoplasmic reticulum (e.g., calreticulin and calcium signaling (e.g., 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase β-2 [PLCB2] were specifically identified in activated LX-2 cells. Additionally, PLCB2 expression was upregulated in the cytoplasm of the activated LX-2 cells, as well as in the hepatocytes and sinusoidal cells of liver cirrhosis tissues. In conclusion, the results of this study may aid future investigations to find new molecular mechanisms involved in HSC activation and antifibrotic therapeutic targets.

Association between nucleotide mutation of eNOS gene and serum ...

African Journals Online (AJOL)

Various mutation on endothelial nitric oxide synthase (eNOs) gene cause reduced production of NO, the expansion factor (VEF) and may accelerate the process of atherosclerosis. The study was designed to investigate the frequency of T-786C polymorphism of the gene or nucleotide mutation of eNOS gene in patients ...

Characterization of Vesicular Stomatitis Virus Recombinants That Express and Incorporate High Levels of Hepatitis C Virus Glycoproteins

OpenAIRE

Buonocore, Linda; Blight, Keril J.; Rice, Charles M.; Rose, John K.

2002-01-01

We generated recombinant vesicular stomatitis viruses (VSV) expressing genes encoding hybrid proteins consisting of the extracellular domains of hepatitis C virus (HCV) glycoproteins fused at different positions to the transmembrane and cytoplasmic domains of the VSV G glycoprotein (E1G and E2G). We show that these chimeric proteins are transported to the cell surface and incorporated into VSV virions efficiently. We also generated VSV recombinants in which the gene encoding the VSV G protein...

The E2.65A mutation disrupts dynamic binding poses of SB269652 at the dopamine D2 and D3 receptors.

Directory of Open Access Journals (Sweden)

Ravi Kumar Verma

2018-01-01

Full Text Available The dopamine D2 and D3 receptors (D2R and D3R are important targets for antipsychotics and for the treatment of drug abuse. SB269652, a bitopic ligand that simultaneously binds both the orthosteric binding site (OBS and a secondary binding pocket (SBP in both D2R and D3R, was found to be a negative allosteric modulator. Previous studies identified Glu2.65 in the SBP to be a key determinant of both the affinity of SB269652 and the magnitude of its cooperativity with orthosteric ligands, as the E2.65A mutation decreased both of these parameters. However, the proposed hydrogen bond (H-bond between Glu2.65 and the indole moiety of SB269652 is not a strong interaction, and a structure activity relationship study of SB269652 indicates that this H-bond may not be the only element that determines its allosteric properties. To understand the structural basis of the observed phenotype of E2.65A, we carried out molecular dynamics simulations with a cumulative length of ~77 μs of D2R and D3R wild-type and their E2.65A mutants bound to SB269652. In combination with Markov state model analysis and by characterizing the equilibria of ligand binding modes in different conditions, we found that in both D2R and D3R, whereas the tetrahydroisoquinoline moiety of SB269652 is stably bound in the OBS, the indole-2-carboxamide moiety is dynamic and only intermittently forms H-bonds with Glu2.65. Our results also indicate that the E2.65A mutation significantly affects the overall shape and size of the SBP, as well as the conformation of the N terminus. Thus, our findings suggest that the key role of Glu2.65 in mediating the allosteric properties of SB269652 extends beyond a direct interaction with SB269652, and provide structural insights for rational design of SB269652 derivatives that may retain its allosteric properties.

Interaction and interdependent packaging of tegument protein UL11 and glycoprotein e of herpes simplex virus.

Science.gov (United States)

Han, Jun; Chadha, Pooja; Meckes, David G; Baird, Nicholas L; Wills, John W

2011-09-01

The UL11 tegument protein of herpes simplex virus plays a critical role in the secondary envelopment; however, the mechanistic details remain elusive. Here, we report a new function of UL11 in the budding process in which it directs efficient acquisition of glycoprotein E (gE) via a direct interaction. In vitro binding assays showed that the interaction required only the first 28, membrane-proximal residues of the cytoplasmic tail of gE, and the C-terminal 26 residues of UL11. A second, weaker binding site was also found in the N-terminal half of UL11. The significance of the gE-UL11 interaction was subsequently investigated with viral deletion mutants. In the absence of the gE tail, virion packaging of UL11, but not other tegument proteins such as VP22 and VP16, was reduced by at least 80%. Reciprocally, wild-type gE packaging was also drastically reduced by about 87% in the absence of UL11, and this defect could be rescued in trans by expressing U(L)11 at the U(L)35 locus. Surprisingly, a mutant that lacks the C-terminal gE-binding site of UL11 packaged nearly normal amounts of gE despite its strong interaction with the gE tail in vitro, indicating that the interaction with the UL11 N terminus may be important. Mutagenesis studies of the UL11 N terminus revealed that the association of UL11 with membrane was not required for this function. In contrast, the UL11 acidic cluster motif was found to be critical for gE packaging and was not replaceable with foreign acidic clusters. Together, these results highlight an important role of UL11 in the acquisition of glycoprotein-enriched lipid bilayers, and the findings may also have important implications for the role of UL11 in gE-mediated cell-to-cell spread.

Frequency of BRAF V600E Mutation in the Mexican Population of Patients With Metastatic Melanoma

Directory of Open Access Journals (Sweden)

Erika Ruiz-Garcia

2017-06-01

Full Text Available Purpose: The BRAF V600E mutation has been described in melanomas occurring in the Caucasian, European, and Asian populations. However, in the Mexican population, the status and clinical significance of BRAF mutation has not been researched on a large scale. Methods: Consecutive BRAF-tested Mexican patients with metastatic melanoma (n = 127 were analyzed for mutations in exon 15 of the BRAF gene in genomic DNA by real-time polymerase chain reaction technology for amplification and detection. The results were correlated with the clinical-pathologic features and the prognosis of the patients. Results: The frequency of somatic mutation V600E within the BRAF gene was 54.6% (43 of 127 patients. Nodular melanoma was the most prevalent subtype in our population, with BRAF mutations in 37.2% (16 of 55 patients. In contrast, superficial spread had a frequency of 18.6% BRAF mutation (eight of 24. Other clinicopathologic features were assessed to correlate with the mutation status. Conclusion: This study searched for the most prevalent BRAF V600E mutation type in melanoma in a heterogeneous population from Mexico. Nodular melanoma was found to be the most prevalent in metastatic presentation and the presence of BRAF V600E mutation, perhaps related to the mixed ancestry; in the north, ancestry is predominantly European and in the south, it is predominantly Asian. The outcomes of the mutation correlations were similar to those found in other populations.

Characterisation of the epitope for a herpes simplex virus glycoprotein B-specific monoclonal antibody with high protective capacity.

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Däumer, Martin P; Schneider, Beate; Giesen, Doris M; Aziz, Sheriff; Kaiser, Rolf; Kupfer, Bernd; Schneweis, Karl E; Schneider-Mergener, Jens; Reineke, Ulrich; Matz, Bertfried; Eis-Hübinger, Anna M

2011-05-01

Monoclonal antibody (MAb) 2c, specific for glycoprotein B of herpes simplex virus (HSV), had been shown to mediate clearance of infection from the mucous membranes of mice, thereby completely inhibiting mucocutaneous inflammation and lethality, even in mice depleted of both CD4(+) and CD8(+) cells. Additionally, ganglionic infection was highly restricted. In vitro, MAb 2c exhibits a potent complement-independent neutralising activity against HSV type 1 and 2, completely inhibits the viral cell-to-cell spread as well as the syncytium formation induced by syncytial HSV strains (Eis-Hübinger et al. in Intervirology 32:351-360, 1991; Eis-Hübinger et al. in J Gen Virol 74:379-385, 1993). Here, we describe the mapping of the epitope for MAb 2c. The antibody was found to recognise a discontinuous epitope comprised of the HSV type 1 glycoprotein B residues 299 to 305 and one or more additional discontinuous regions that can be mimicked by the sequence FEDF. Identification of the epitope was confirmed by loss of antibody binding to mutated glycoprotein B with replacement of the epitopic key residues, expressed in COS-1 cells. Similarly, MAb 2c was not able to neutralise HSV mutants with altered key residues, and MAb 2c was ineffective in mice inoculated with such mutants. Interestingly, identification and fine-mapping of the discontinuous epitope was not achieved by binding studies with truncated glycoprotein B variants expressed in COS cells but by peptide scanning with synthetic overlapping peptides and peptide key motif analysis. Reactivity of MAb 2c was immensely increased towards a peptide composed of the glycoprotein B residues 299 to 305, a glycine linker, and a C-terminal FEDF motif. If it could be demonstrated that antibodies of the specificity and bioactivity of MAb 2c can be induced by the epitope or a peptide mimicking the epitope, strategies for active immunisation might be conceivable.

The first USH2A mutation analysis of Japanese autosomal recessive retinitis pigmentosa patients: a totally different mutation profile with the lack of frequent mutations found in Caucasian patients.

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Zhao, Yang; Hosono, Katsuhiro; Suto, Kimiko; Ishigami, Chie; Arai, Yuuki; Hikoya, Akiko; Hirami, Yasuhiko; Ohtsubo, Masafumi; Ueno, Shinji; Terasaki, Hiroko; Sato, Miho; Nakanishi, Hiroshi; Endo, Shiori; Mizuta, Kunihiro; Mineta, Hiroyuki; Kondo, Mineo; Takahashi, Masayo; Minoshima, Shinsei; Hotta, Yoshihiro

2014-09-01

Retinitis pigmentosa (RP) is a highly heterogeneous genetic disease. The USH2A gene, which accounts for approximately 74-90% of Usher syndrome type 2 (USH2) cases, is also one of the major autosomal recessive RP (arRP) causative genes among Caucasian populations. To identify disease-causing USH2A gene mutations in Japanese RP patients, all 73 exons were screened for mutations by direct sequencing. In total, 100 unrelated Japanese RP patients with no systemic manifestations were identified, excluding families with obvious autosomal dominant inheritance. Of these 100 patients, 82 were included in this present study after 18 RP patients with very likely pathogenic EYS (eyes shut homolog) mutations were excluded. The mutation analysis of the USH2A revealed five very likely pathogenic mutations in four patients. A patient had only one very likely pathogenic mutation and the others had two of them. Caucasian frequent mutations p.C759F in arRP and p.E767fs in USH2 were not found. All the four patients exhibited typical clinical features of RP. The observed prevalence of USH2A gene mutations was approximately 4% among Japanese arRP patients, and the profile of the USH2A gene mutations differed largely between Japanese patients and previously reported Caucasian populations.

Meta-Analyses of Association Between BRAFV600E Mutation and Clinicopathological Features of Papillary Thyroid Carcinoma

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Qing Zhang

2016-02-01

Full Text Available Background/Aims: The function of BRAF V600E as a prognostic biomarker continues controversial by reason of conflicting results in the published articles. Methods: A systematical literature search for relevant articles was performed in PubMed, Cochrane Library, Google Scholar, Medline and Embase updated to August 5, 2015. The Chi-square test and I2 were employed to examine statistical heterogeneity. Pooled ORs with their corresponding 95% confidence intervals (95%CIs were calculated to assess the relationship between clinicopathological features and BRAFV600E mutation. Subgroup analyses by ethnicity were also performed to explore the potential sources of heterogeneity. Furthermore, publication bias was detected using the funnel plot and all statistical analyses were conducted by the software of R 3.12. Results: Of 25,241 cases with PTC, 15,290 (60.6% were positive for BRAF mutation and 9,951 (39.4% were tested negative for BRAF mutation. Negative status of BRAFV600E mutation negative was significantly associated with gender (OR = 0.90, 95%CI = 0.83-0.97 and concomitant hashimoto thyroiditis (OR = 0.53, 95%CI = 0.43-0.64. By contrast, positive status of BRAFV600E mutation was a significant predictor of multifocality (OR = 1.23; 95%CI = 1.14-1.32, extrathyroidal extension (OR = 2.23; 95%CI = 1.90-2.63, TNM stage (OR = 1.67; 95%CI = 1.53-1.81, lymph node metastasis (OR = 1.67; 95%CI = 1.45-1.93, vascular invasion (OR = 1.47; 95%CI = 1.22-1.79 and recurrence/persistence (OR = 2.33; 95%CI = 1.71-3.18. However, there was no significant association between BRAFV600E mutation and factors including age > 45 (OR = 0.98; 95%CI = 0.89-1.07, tumor size (OR = 0.84; 95%CI = 0.64-1.09 and distant metastasis (OR = 1.23; 95%CI = 0.67-2.27. Conclusion: This meta-analysis confirmed significant associations between BRAFV600E mutation and female gender, multifocality, ETE, LNM, TNM stage, concomitant hashimoto thyroiditis, vascular invasion and recurrence

Genetic analysis of the SARS-coronavirus spike glycoprotein functional domains involved in cell-surface expression and cell-to-cell fusion

International Nuclear Information System (INIS)

Petit, Chad M.; Melancon, Jeffrey M.; Chouljenko, Vladimir N.; Colgrove, Robin; Farzan, Michael; Knipe, David M.; Kousoulas, K.G.

2005-01-01

The SARS-coronavirus (SARS-CoV) is the etiological agent of severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. To delineate functional domains of the SARS-CoV S glycoprotein, single point mutations, cluster-to-lysine and cluster-to-alanine mutations, as well as carboxyl-terminal truncations were investigated in transient expression experiments. Mutagenesis of either the coiled-coil domain of the S glycoprotein amino terminal heptad repeat, the predicted fusion peptide, or an adjacent but distinct region, severely compromised S-mediated cell-to-cell fusion, while intracellular transport and cell-surface expression were not adversely affected. Surprisingly, a carboxyl-terminal truncation of 17 amino acids substantially increased S glycoprotein-mediated cell-to-cell fusion suggesting that the terminal 17 amino acids regulated the S fusogenic properties. In contrast, truncation of 26 or 39 amino acids eliminating either one or both of the two endodomain cysteine-rich motifs, respectively, inhibited cell fusion in comparison to the wild-type S. The 17 and 26 amino-acid deletions did not adversely affect S cell-surface expression, while the 39 amino-acid truncation inhibited S cell-surface expression suggesting that the membrane proximal cysteine-rich motif plays an essential role in S cell-surface expression. Mutagenesis of the acidic amino-acid cluster in the carboxyl terminus of the S glycoprotein as well as modification of a predicted phosphorylation site within the acidic cluster revealed that this amino-acid motif may play a functional role in the retention of S at cell surfaces. This genetic analysis reveals that the SARS-CoV S glycoprotein contains extracellular domains that regulate cell fusion as well as distinct endodomains that function in intracellular transport, cell-surface expression, and cell fusion

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....../release. Studies of E1/E2 heterodimerization showed no differences in intracellular E1/E2 interaction for chimeric constructs with or without E2 stem region mutations. Interestingly, the E2 stem region mutations allowed efficient entry, which was verified in 1a-E1/1b-E2 HCV pseudoparticle assays. A CD81 inhibition...

Functional analysis of HNPCC-related missense mutations in MSH2

International Nuclear Information System (INIS)

Luetzen, Anne; Wind, Niels de; Georgijevic, Dubravka; Nielsen, Finn Cilius; Rasmussen, Lene Juel

2008-01-01

Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions

Functional analysis of HNPCC-related missense mutations in MSH2

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Luetzen, Anne [Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark); Wind, Niels de; Georgijevic, Dubravka [Department of Toxicogenetics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden (Netherlands); Nielsen, Finn Cilius [Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen (Denmark); Rasmussen, Lene Juel [Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark)], E-mail: ljr@ruc.dk

2008-10-14

Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions.

Identification of two novel mutations, PSEN1 E280K and PRNP G127S, in a Malaysian family

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Ch’ng GS

2015-09-01

Full Text Available Gaik-Siew Ch’ng,1,* Seong Soo A An,2,* Sun Oh Bae,2 Eva Bagyinszky,2 SangYun Kim3,41Department of Genetics, Kuala Lumpur Hospital, Malaysia; 2Department of Bionano Technology, Gachon University, 3Department of Neurology, Seoul National University College of Medicine, 4Seoul National University Bundang Hospital, South Korea*These authors contributed equally to this workAbstract: Alzheimer’s disease (AD is the most common form of dementia, which can be categorized into two main forms: early onset AD and late onset AD. The genetic background of early onset AD is well understood, and three genes, the APP, PSEN1, and PSEN2 have been identified as causative genes. In the current study, we tested three siblings from Malaysia who were diagnosed with early onset dementia, as well as their available family members. The family history was positive as their deceased father was similarly affected. Patients were tested for mutations in APP, PSEN1, PSEN2, and PRNP. A novel variant, E280K, was discovered in exon 8 of PSEN1 in the three siblings. In silico analyses with SIFT, SNAP, and PolyPhen2 prediction tools and three-dimensional modeling were performed, and the results suggested that the mutation is probably a pathogenic variant. Two additional pathogenic mutations were previously been described for codon 280, E280A, and E280G, which could support the importance of the E280 residue in the PS1 protein contributing to the pathogenic nature of E280K. Additional ten family members were screened for the E280K mutation, and all of them were negative. Six of them presented with a variety of neuropsychiatric symptoms, including learning disabilities, epilepsy, and schizophrenia, while four family members were asymptomatic. A novel PRNP G127S mutation was found in a step-niece of the three siblings harboring the PSEN1 E280K mutation. In silico predictions for PRNP G127S mutation suggested that this might be possibly a damaging variant. Additional studies to

Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus

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Beuy Joob

2014-12-01

Full Text Available The drug searching for combating the present outbreak of Ebola virus infection is the urgent activity at present. Finding the new effective drug at present must base on the molecular analysis of the pathogenic virus. The in-depth analysis of the viral protein to find the binding site, active pocket is needed. Here, the authors analyzed the envelope glycoprotein GP2 from Ebola virus. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus was done. According to this assessment, 7 active pockets with varied druggability could be identified.

BRAF V600E mutations are common in pleomorphic xanthoastrocytoma: diagnostic and therapeutic implications.

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Dora Dias-Santagata

2011-03-01

Full Text Available Pleomorphic xanthoastrocytoma (PXA is low-grade glial neoplasm principally affecting children and young adults. Approximately 40% of PXA are reported to recur within 10 years of primary resection. Upon recurrence, patients receive radiation therapy and conventional chemotherapeutics designed for high-grade gliomas. Genetic changes that can be targeted by selective therapeutics have not been extensively evaluated in PXA and ancillary diagnostic tests to help discriminate PXA from other pleomorphic and often more aggressive astrocytic malignancies are limited. In this study, we apply the SNaPshot multiplexed targeted sequencing platform in the analysis of brain tumors to interrogate 60 genetic loci that are frequently mutated in 15 cancer genes. In our analysis we detect BRAF V600E mutations in 12 of 20 (60% WHO grade II PXA, in 1 of 6 (17% PXA with anaplasia and in 1 glioblastoma arising in a PXA. Phospho-ERK was detected in all tumors independent of the BRAF mutation status. BRAF duplication was not detected in any of the PXA cases. BRAF V600E mutations were identified in only 2 of 71 (2.8% glioblastoma (GBM analyzed, including 1 of 9 (11.1% giant cell GBM (gcGBM. The finding that BRAF V600E mutations are common in the majority of PXA has important therapeutic implications and may help in differentiating less aggressive PXAs from lethal gcGBMs and GBMs.

Dystroglycan and muscular dystrophies related to the dystrophin-glycoprotein complex.

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Sciandra, Francesca; Bozzi, Manuela; Bianchi, Marzia; Pavoni, Ernesto; Giardina, Bruno; Brancaccio, Andrea

2003-01-01

Dystroglycan (DG) is an adhesion molecule composed of two subunits, alpha and beta, that are produced by the post-translational cleavage of a single precursor molecule. DG is a pivotal component of the dystrophin-glycoprotein complex (DGC), which connects the extracellular matrix to the cytoskeleton in skeletal muscle and many other tissues. Some muscular dystrophies are caused by mutations of DGC components, such as dystrophin, sarcoglycan or laminin-2, or also of DGC-associated molecules, such as caveolin-3. DG-null mice died during early embriogenesis and no neuromuscular diseases directly associated to genetic abnormalities of DG were identified so far. However, DG plays a crucial role for muscle integrity since its targeting at the sarcolemma is often perturbed in DGC-related neuromuscular disorders.

Modification of UV-induced mutation frequency and cell survival of Escherichia coli B/r WP2 trpE65 by treatment before irradiation

International Nuclear Information System (INIS)

Doudney, C.O.; Rinaldi, C.N.

1984-01-01

The UV radiation survival curve of exponentially growing cultures of Escherichia coli B/r WP2 trpE65 was modified by pretreatment for short incubation periods (up to 20 min) with chloramphenicol such that an extended exponential section of intermediate slope appeared between the shoulder and the final exponential slope. Surges of mutation to tryptophan independence occurred with each increase in slope of the survival curve. These surges were separated by extended sections of little mutation. Nalidixic acid prevented both the changes in survival and mutation. Mutation curves obtained with overnight cultures had three extended sections of little mutation alternating with section of high mutation. Reincubation for 60 min in fresh medium reduced or eliminated the low-response sections. These reappeared after 80 to 90 min, when DNA had doubled in the culture and before the initial synchronous cell divisions had occurred. Nalidixic acid prevented this reappearance

Novel Calmodulin (CALM2) Mutations Associated with Congenital Arrhythmia Susceptibility

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Makita, Naomasa; Yagihara, Nobue; Crotti, Lia; Johnson, Christopher N.; Beckmann, Britt-Maria; Roh, Michelle S.; Shigemizu, Daichi; Lichtner, Peter; Ishikawa, Taisuke; Aiba, Takeshi; Homfray, Tessa; Behr, Elijah R.; Klug, Didier; Denjoy, Isabelle; Mastantuono, Elisa; Theisen, Daniel; Tsunoda, Tatsuhiko; Satake, Wataru; Toda, Tatsushi; Nakagawa, Hidewaki; Tsuji, Yukiomi; Tsuchiya, Takeshi; Yamamoto, Hirokazu; Miyamoto, Yoshihiro; Endo, Naoto; Kimura, Akinori; Ozaki, Kouichi; Motomura, Hideki; Suda, Kenji; Tanaka, Toshihiro; Schwartz, Peter J.; Meitinger, Thomas; Kääb, Stefan; Guicheney, Pascale; Shimizu, Wataru; Bhuiyan, Zahurul A.; Watanabe, Hiroshi; Chazin, Walter J.; George, Alfred L.

2014-01-01

Background Genetic predisposition to life-threatening cardiac arrhythmias such as in congenital long-QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) represent treatable causes of sudden cardiac death in young adults and children. Recently, mutations in calmodulin (CALM1, CALM2) have been associated with severe forms of LQTS and CPVT, with life-threatening arrhythmias occurring very early in life. Additional mutation-positive cases are needed to discern genotype-phenotype correlations associated with calmodulin mutations. Methods and Results We employed conventional and next-generation sequencing approaches including exome analysis in genotype-negative LQTS probands. We identified five novel de novo missense mutations in CALM2 in three subjects with LQTS (p.N98S, p.N98I, p.D134H) and two subjects with clinical features of both LQTS and CPVT (p.D132E, p.Q136P). Age of onset of major symptoms (syncope or cardiac arrest) ranged from 1–9 years. Three of five probands had cardiac arrest and one of these subjects did not survive. Although all probands had LQTS, two subjects also exhibited electrocardiographic features consistent with CPVT. The clinical severity among subjects in this series was generally less than that originally reported for CALM1 and CALM2 associated with recurrent cardiac arrest during infancy. Four of five probands responded to β-blocker therapy whereas one subject with mutation p.Q136P died suddenly during exertion despite this treatment. Mutations affect conserved residues located within calcium binding loops III (p.N98S, p.N98I) or IV (p.D132E, p.D134H, p.Q136P) and caused reduced calcium binding affinity. Conclusions CALM2 mutations can be associated with LQTS and with overlapping features of LQTS and CPVT. PMID:24917665

The hydroxyapatite-binding regions of a rat salivary glycoprotein.

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Embery, G; Green, D R

1989-09-01

The regions of a salivary sulphated glycoprotein which are involved in its attachment to hydroxyapatite (Biogel HTP) have been characterised. The sulphated glycoprotein, a 35S-labelled preparation from mixed palatal and buccal minor gland secretions of the rat was bound onto hydroxyapatite and the resultant glycoprotein-hydroxyapatite complex was sequentially digested with pronase E and alpha-L-fucosidase, a treatment which released 86.8% +/- 1.7% of the radioactivity of the initially bound glycoprotein. The fragments which remained attached to the hydroxyapatite after enzymic digestion were fractionated on Sephadex G-25 and analysed for carbohydrate and amino acid components. A range of amino acids were detected which could reflect both glycosylated and non-glycosylated-binding regions. Sialic acid, although considered to be involved in the attachment process was not detected in any of the fragments remaining after enzymic digestion, a finding which provides indirect evidence that the enzymically liberated products do not subsequently re-attach to the hydroxyapatite surface. The notable feature of the fractions with average Mr estimated at 1000 or less is the high proportion of N-acetylhexosamine and N-acetylgalactosamine. It is apparent that the hexosamine residues, which normally bear the ester sulphate moieties of sulphated glycoproteins, play an important role in the attachment of sulphated glycoproteins to hydroxyapatite.

The influence of preirradiation history of E. coli WP2 cells on the residual fixation of mutations in rpsL. (strA) locus

International Nuclear Information System (INIS)

Filippov, V.D.

1986-01-01

The values of residual fixation of strA mutations in E.coli culture, irradiated by UV-light (6.8 J/m 2 ) in different physiological states and conforming to different in depth strA mutation frequency decrease in postirradiation incubation under conditions unfavourable for protein synthesis are determined. By residual fixation one should mean accumulation of strA mutations stable to antimutagenous effect of photoreactivating light in cell population incubated in buffer after UV radiation. It is established that residual fixation is small in cultures, conforming to deep decrease, and is a factor (about 40% of strA mutations is fixed) in a culture, conforming to moderate decrease (about 60% of strA mutations disappears) of mutation frequency in incubation under conditions unfavourable for protein synthesis. The conclusion is made that the depth of strA mutation frequency decrease, taking place under the influence of mfd system, depends on the level of residual fixation of this mutations. It is supposed that residual fixation is caused by rpsL (strA) locus introduction in replication cycle initiated after radiation

Up-regulation of P-glycoprotein expression by catalase via JNK activation in HepG2 cells.

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Li, Lin; Xu, Jianfeng; Min, Taishan; Huang, Weida

2006-01-01

Overexpression of the MDR1 gene is one of the reasons for multidrug resistance (MDR). Some studies suggested that antioxidants could down-regulate MDR1 expression as a possible cancer treatment. In this report, we try to determine the effects of antioxidants (catalase or N-acetylcysteine [NAC]) on the regulation of intrinsic MDR1 overexpression in HepG2 cells. Adding catalase or N-acetylcysteine to the HepG2 culture led to a significant increase of MDR1 mRNA and P-glycoprotein drug transporter activity. After catalase or NAC treatment, a reduced intracellular reactive oxygen species (ROS) was observed. The JNK inhibitor SP600125 abolished the positive effects of catalase on drug transporter activity in a dose-dependent manner. Furthermore, the up-regulation of P-glycoprotein functions by catalase was only observed in HepG2 cells but not in other cell lines tested (MCF-7, A549, A431). These data suggested that catalase can up-regulate P-glycoprotein expression in HepG2 cells via reducing intracellular ROS, and JNK may mediate this process.

The non-small cell lung cancer EGFR extracellular domain mutation, M277E, is oncogenic and drug-sensitive

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Yu S

2017-09-01

Full Text Available Su Yu,1,2 Yang Zhang,1 Yunjian Pan,1 Chao Cheng,1,3 Yihua Sun,1,3 Haiquan Chen1–4 1Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; 2Cancer Research Center, Fudan University Shanghai Cancer Center, Shanghai, China; 3Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China; 4Institutes of Biomedical Sciences, Fudan University, Shanghai, China Purpose: To identify novel oncogenic mutations in non-small cell lung cancer patient specimens that lack mutations in known targetable genes (“pan-negative” patients.Methods: Comprehensive mutational analyses were performed on 1,356 lung adenocarcinoma specimens. In this cohort of patients, common lung cancer oncogenic driver mutations were detected in the epidermal growth factor receptor (EGFR kinase domain, the human epidermal growth factor receptor 2 kinase domain, as well as the KRAS, BRAF, ALK, ROS1 and RET genes. A sub-cohort of pan-negative patient specimens was assayed for mutations in the EGFR extracellular domain (ECD. Additionally, EGFR mutant NIH-3T3 stable cell lines were constructed and assessed for protein content, anchorage-independent growth, and tumor formation in xenograft models to identify oncogenic mutations. BaF3 lymphocytes were also used to test sensitivities of the mutations to tyrosine kinase inhibitors.Results: In pan-negative lung adenocarcinoma cases, a novel oncogenic EGFR ECD mutation was identified (M277E. EGFR M277E mutations encoded oncoproteins that transformed NIH-3T3 cells to grow in the absence of exogenous epidermal growth factor. Transformation was further evidenced by anchorage-independent growth and tumor formation in immunocompromised xenograft mouse models. Finally, as seen in the canonical EGFR L858R mutation, the M277E mutation conferred sensitivity to both erlotinib and cetuximab in BaF3 cell lines and to erlotinib in xenograft models.Conclusion: Here, a new EGFR driver mutation, M277E

Functional Characterization of Adaptive Mutations during the West African Ebola Virus Outbreak.

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Dietzel, Erik; Schudt, Gordian; Krähling, Verena; Matrosovich, Mikhail; Becker, Stephan

2017-01-15

The Ebola virus (EBOV) outbreak in West Africa started in December 2013, claimed more than 11,000 lives, threatened to destabilize a whole region, and showed how easily health crises can turn into humanitarian disasters. EBOV genomic sequences of the West African outbreak revealed nonsynonymous mutations, which induced considerable public attention, but their role in virus spread and disease remains obscure. In this study, we investigated the functional significance of three nonsynonymous mutations that emerged early during the West African EBOV outbreak. Almost 90% of more than 1,000 EBOV genomes sequenced during the outbreak carried the signature of three mutations: a D759G substitution in the active center of the L polymerase, an A82V substitution in the receptor binding domain of surface glycoprotein GP, and an R111C substitution in the self-assembly domain of RNA-encapsidating nucleoprotein NP. Using a newly developed virus-like particle system and reverse genetics, we found that the mutations have an impact on the functions of the respective viral proteins and on the growth of recombinant EBOVs. The mutation in L increased viral transcription and replication, whereas the mutation in NP decreased viral transcription and replication. The mutation in the receptor binding domain of the glycoprotein GP improved the efficiency of GP-mediated viral entry into target cells. Recombinant EBOVs with combinations of the three mutations showed a growth advantage over the prototype isolate Makona C7 lacking the mutations. This study showed that virus variants with improved fitness emerged early during the West African EBOV outbreak. The dimension of the Ebola virus outbreak in West Africa was unprecedented. Amino acid substitutions in the viral L polymerase, surface glycoprotein GP, and nucleocapsid protein NP emerged, were fixed early in the outbreak, and were found in almost 90% of the sequences. Here we showed that these mutations affected the functional activity of

The quality control of glycoprotein folding in the endoplasmic reticulum, a trip from trypanosomes to mammals

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A.J. Parodi

1998-05-01

Full Text Available The present review deals with the stages of synthesis and processing of asparagine-linked oligosaccharides occurring in the lumen of the endoplasmic reticulum and their relationship to the acquisition by glycoproteins of their proper tertiary structures. Special emphasis is placed on reactions taking place in trypanosomatid protozoa since their study has allowed the detection of the transient glucosylation of glycoproteins catalyzed by UDP-Glc:glycoprotein glucosyltransferase and glucosidase II. The former enzyme has the unique property of covalently tagging improperly folded conformations by catalyzing the formation of protein-linked Glc1Man7GlcNAc2, Glc1Man8GlcNac2 and Glc1Man9GlcNAc2 from the unglucosylated proteins. Glucosyltransferase is a soluble protein of the endoplasmic reticulum that recognizes protein domains exposed in denatured but not in native conformations (probably hydrophobic amino acids and the innermost N-acetylglucosamine unit that is hidden from macromolecular probes in most native glycoproteins. In vivo, the glucose units are removed by glucosidase II. The influence of oligosaccharides in glycoprotein folding is reviewed as well as the participation of endoplasmic reticulum chaperones (calnexin and calreticulin that recognize monoglucosylated species in the same process. A model for the quality control of glycoprotein folding in the endoplasmic reticulum, i.e., the mechanism by which cells recognize the tertiary structure of glycoproteins and only allow transit to the Golgi apparatus of properly folded species, is discussed. The main elements of this control are calnexin and calreticulin as retaining components, the UDP-Glc:glycoprotein glucosyltransferase as a sensor of tertiary structures and glucosidase II as the releasing agent.

Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

Energy Technology Data Exchange (ETDEWEB)

Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

1980-01-01

Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

Anti-beta2 glycoprotein 1 and the anti-phospholipid syndrome.

LENUS (Irish Health Repository)

Keane, Pearse A

2012-02-03

PURPOSE: To describe a patient who presented with bilateral retinal vascular occlusion and the use of anti-beta2 glycoprotein 1 (GPI) antibody testing in the diagnosis of antiphospholipid syndrome. DESIGN: Observational case report. METHODS: Hematological investigations were performed on a 49-year-old man who presented with rapid onset of bilateral severe central retinal vein occlusion. RESULTS: Lupus anticoagulant and anticardiolipin antibody testing was negative. Markedly raised titers of anti-beta2 GPI antibodies were detected on two separate occasions. CONCLUSIONS: The raised titers of anti-beta2 GPI antibodies were considered to strongly suggest an underlying diagnosis of the antiphospholipid syndrome.

O-acetylation of the serine-rich repeat glycoprotein GspB is coordinated with accessory Sec transport.

Directory of Open Access Journals (Sweden)

Ravin Seepersaud

2017-08-01

Full Text Available The serine-rich repeat (SRR glycoproteins are a family of adhesins found in many Gram-positive bacteria. Expression of the SRR adhesins has been linked to virulence for a variety of infections, including streptococcal endocarditis. The SRR preproteins undergo intracellular glycosylation, followed by export via the accessory Sec (aSec system. This specialized transporter is comprised of SecA2, SecY2 and three to five accessory Sec proteins (Asps that are required for export. Although the post-translational modification and transport of the SRR adhesins have been viewed as distinct processes, we found that Asp2 of Streptococcus gordonii also has an important role in modifying the SRR adhesin GspB. Biochemical analysis and mass spectrometry indicate that Asp2 is an acetyltransferase that modifies N-acetylglucosamine (GlcNAc moieties on the SRR domains of GspB. Targeted mutations of the predicted Asp2 catalytic domain had no effect on transport, but abolished acetylation. Acetylated forms of GspB were only detected when the protein was exported via the aSec system, but not when transport was abolished by secA2 deletion. In addition, GspB variants rerouted to export via the canonical Sec pathway also lacked O-acetylation, demonstrating that this modification is specific to export via the aSec system. Streptococci expressing GspB lacking O-acetylated GlcNAc were significantly reduced in their ability bind to human platelets in vitro, an interaction that has been strongly linked to virulence in the setting of endocarditis. These results demonstrate that Asp2 is a bifunctional protein involved in both the post-translational modification and transport of SRR glycoproteins. In addition, these findings indicate that these processes are coordinated during the biogenesis of SRR glycoproteins, such that the adhesin is optimally modified for binding. This requirement for the coupling of modification and export may explain the co-evolution of the SRR

Parkinson disease: α-synuclein mutational screening and new clinical insight into the p.E46K mutation.

Science.gov (United States)

Pimentel, Márcia M G; Rodrigues, Fabíola C; Leite, Marco Antônio A; Campos Júnior, Mário; Rosso, Ana Lucia; Nicaretta, Denise H; Pereira, João S; Silva, Delson José; Della Coletta, Marcus V; Vasconcellos, Luiz Felipe R; Abreu, Gabriella M; Dos Santos, Jussara M; Santos-Rebouças, Cíntia B

2015-06-01

Amongst Parkinson's disease-causing genetic factors, missense mutations and genomic multiplications in the gene encoding α-synuclein are well established causes of the disease, although genetic data in populations with a high degree of admixture, such as the Brazilian one, are still scarce. In this study, we conducted a molecular screening of α-synuclein point mutations and copy number variation in the largest cohort of Brazilian patients with Parkinson's disease (n = 549) and also in twelve Portuguese and one Bolivian immigrants. Genomic DNA was isolated from peripheral blood leukocytes or saliva, and the mutational screening was performed by quantitative and qualitative real-time PCR. The only alteration identified was the p.E46K mutation in a 60-year-old man, born in Bolivia, with a familial history of autosomal dominant Parkinson's disease. This is the second family ever reported, in which this rare pathogenic mutation is segregating. The same mutation was firstly described ten years ago in a Spanish family with a neurodegenerative syndrome combining parkinsonism, dementia and visual hallucinations. The clinical condition of our proband reveals a less aggressive phenotype than previously described and reinforces that marked phenotypic heterogeneity is common among patients with Parkinson's disease, even among those carriers sharing the same mutation. Our findings add new insight into the preexisting information about α-synuclein p.E46K, improving our understanding about the endophenotypes associated to this mutation and corroborate that missense alterations and multiplications in α-synuclein are uncommon among Brazilian patients with Parkinson's disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

BRCA2, EGFR, and NTRK mutations in mismatch repair-deficient colorectal cancers with MSH2 or MLH1 mutations.

Science.gov (United States)

Deihimi, Safoora; Lev, Avital; Slifker, Michael; Shagisultanova, Elena; Xu, Qifang; Jung, Kyungsuk; Vijayvergia, Namrata; Ross, Eric A; Xiu, Joanne; Swensen, Jeffrey; Gatalica, Zoran; Andrake, Mark; Dunbrack, Roland L; El-Deiry, Wafik S

2017-06-20

Deficient mismatch repair (MMR) and microsatellite instability (MSI) contribute to ~15% of colorectal cancer (CRCs). We hypothesized MSI leads to mutations in DNA repair proteins including BRCA2 and cancer drivers including EGFR. We analyzed mutations among a discovery cohort of 26 MSI-High (MSI-H) and 558 non-MSI-H CRCs profiled at Caris Life Sciences. Caris-profiled MSI-H CRCs had high mutation rates (50% vs 14% in non-MSI-H, P MLH1-mutant CRCs showed higher mutation rates in BRCA2 compared to non-MSH2/MLH1-mutant tumors (38% vs 6%, P MLH1-mutant CRCs included 75 unique mutations not known to occur in breast or pancreatic cancer per COSMIC v73. Only 5 deleterious BRCA2 mutations in CRC were previously reported in the BIC database as germ-line mutations in breast cancer. Some BRCA2 mutations were predicted to disrupt interactions with partner proteins DSS1 and RAD51. Some CRCs harbored multiple BRCA2 mutations. EGFR was mutated in 45.5% of MSH2/MLH1-mutant and 6.5% of non-MSH2/MLH1-mutant tumors (P MLH1-mutant CRC including NTRK1 I699V, NTRK2 P716S, and NTRK3 R745L. Our findings have clinical relevance regarding therapeutic targeting of BRCA2 vulnerabilities, EGFR mutations or other identified oncogenic drivers such as NTRK in MSH2/MLH1-mutant CRCs or other tumors with mismatch repair deficiency.

Mutations increasing exposure of a receptor binding site epitope in the soluble and oligomeric forms of the caprine arthritis-encephalitis lentivirus envelope glycoprotein

International Nuclear Information System (INIS)

Hoetzel, Isidro; Cheevers, William P.

2005-01-01

The caprine arthritis-encephalitis (CAEV) and ovine maedi-visna (MVV) viruses are resistant to antibody neutralization, a feature shared with all other lentiviruses. Whether the CAEV gp135 receptor binding site(s) (RBS) in the functional surface envelope glycoprotein (Env) is protected from antibody binding, allowing the virus to resist neutralization, is not known. Two CAEV gp135 regions were identified by extrapolating a gp135 structural model that could affect binding of antibodies to the RBS: the V1 region and a short sequence analogous in position to the human immunodeficiency virus type 1 gp120 loop B postulated to be located between two major domains of CAEV gp135. Mutation of isoleucine-166 to alanine in the putative loop B of gp135 increased the affinity of soluble gp135 for the CAEV receptor(s) and goat monoclonal antibody (Mab) F7-299 which recognizes an epitope overlapping the gp135 RBS. The I166A mutation also stabilized or exposed the F7-299 epitope in anionic detergent buffers, indicating that the I166A mutation induces conformational changes and stabilizes the RBS of soluble gp135 and enhances Mab F7-299 binding. In contrast, the affinity of a V1 deletion mutant of gp135 for the receptor and Mab F7-299 and its structural stability did not differ from that of the wild-type gp135. However, both the I166A mutation and the V1 deletion of gp135 increased cell-to-cell fusion activity and binding of Mab F7-299 to the oligomeric Env. Therefore, the CAEV gp135 RBS is protected from antibody binding by mechanisms both dependent and independent of Env oligomerization which are disrupted by the V1 deletion and the I166A mutation, respectively. In addition, we found a correlation between side-chain β-branching at amino acid position 166 and binding of Mab F7-299 to oligomeric Env and cell-to-cell fusion, suggesting local secondary structure constraints in the region around isoleucine-166 as one determinant of gp135 RBS exposure and antibody binding

The UL24 protein of herpes simplex virus 1 affects the sub-cellular distribution of viral glycoproteins involved in fusion

Energy Technology Data Exchange (ETDEWEB)

Ben Abdeljelil, Nawel; Rochette, Pierre-Alexandre; Pearson, Angela, E-mail: angela.pearson@iaf.inrs.ca

2013-09-15

Mutations in UL24 of herpes simplex virus type 1 can lead to a syncytial phenotype. We hypothesized that UL24 affects the sub-cellular distribution of viral glycoproteins involved in fusion. In non-immortalized human foreskin fibroblasts (HFFs) we detected viral glycoproteins B (gB), gD, gH and gL present in extended blotches throughout the cytoplasm with limited nuclear membrane staining; however, in HFFs infected with a UL24-deficient virus (UL24X), staining for the viral glycoproteins appeared as long, thin streaks running across the cell. Interestingly, there was a decrease in co-localized staining of gB and gD with F-actin at late times in UL24X-infected HFFs. Treatment with chemical agents that perturbed the actin cytoskeleton hindered the formation of UL24X-induced syncytia in these cells. These data support a model whereby the UL24 syncytial phenotype results from a mislocalization of viral glycoproteins late in infection. - Highlights: • UL24 affects the sub-cellular distribution of viral glycoproteins required for fusion. • Sub-cellular distribution of viral glycoproteins varies in cell-type dependent manner. • Drugs targeting actin microfilaments affect formation of UL24-related syncytia in HFFs.

E-cadherin destabilization accounts for the pathogenicity of missense mutations in hereditary diffuse gastric cancer.

Directory of Open Access Journals (Sweden)

Joana Simões-Correia

Full Text Available E-cadherin is critical for the maintenance of tissue architecture due to its role in cell-cell adhesion. E-cadherin mutations are the genetic cause of Hereditary Diffuse Gastric Cancer (HDGC and missense mutations represent a clinical burden, due to the uncertainty of their pathogenic role. In vitro and in vivo, most mutations lead to loss-of-function, although the causal factor is unknown for the majority. We hypothesized that destabilization could account for the pathogenicity of E-cadherin missense mutations in HDGC, and tested our hypothesis using in silico and in vitro tools. FoldX algorithm was used to calculate the impact of each mutation in E-cadherin native-state stability, and the analysis was complemented with evolutionary conservation, by SIFT. Interestingly, HDGC patients harbouring germline E-cadherin destabilizing mutants present a younger age at diagnosis or death, suggesting that the loss of native-state stability of E-cadherin accounts for the disease phenotype. To elucidate the biological relevance of E-cadherin destabilization in HDGC, we investigated a group of newly identified HDGC-associated mutations (E185V, S232C and L583R, of which L583R is predicted to be destabilizing. We show that this mutation is not functional in vitro, exhibits shorter half-life and is unable to mature, due to premature proteasome-dependent degradation, a phenotype reverted by stabilization with the artificial mutation L583I (structurally tolerated. Herein we report E-cadherin structural models suitable to predict the impact of the majority of cancer-associated missense mutations and we show that E-cadherin destabilization leads to loss-of-function in vitro and increased pathogenicity in vivo.

An improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein

International Nuclear Information System (INIS)

Dawnay, A.B. St. J.; Thornley, C.; Cattell, W.R.

1982-01-01

A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 0 C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance. (author)

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.

Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

International Nuclear Information System (INIS)

González, Silvia A.; Paladino, Mónica G.; Affranchino, José L.

2012-01-01

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.

Biological characterization of bovine herpesvirus 1 recombinants possessing the vaccine glycoprotein E negative phenotype.

Science.gov (United States)

Muylkens, Benoît; Meurens, François; Schynts, Frédéric; de Fays, Katalin; Pourchet, Aldo; Thiry, Julien; Vanderplasschen, Alain; Antoine, Nadine; Thiry, Etienne

2006-03-31

Intramolecular recombination is a frequent event during the replication cycle of bovine herpesvirus 1 (BoHV-1). Recombinant viruses frequently arise and survive in cattle after concomitant nasal infections with two BoHV-1 mutants. The consequences of this process, related to herpesvirus evolution, have to be assessed in the context of large use of live marker vaccines based on glycoprotein E (gE) gene deletion. In natural conditions, double nasal infections by vaccine and wild-type strains are likely to occur. This situation might generate virulent recombinant viruses inducing a serological response indistinguishable from the vaccine one. This question was addressed by generating in vitro BoHV-1 recombinants deleted in the gE gene from seven wild-type BoHV-1 strains and one mutant strain deleted in the genes encoding gC and gE. In vitro growth properties were assessed by virus production, one step growth kinetics and plaque size assay. Heterogeneity in the biological properties was shown among the investigated recombinant viruses. The results demonstrated that some recombinants, in spite of their gE minus phenotype, have biological characteristics close to wild-type BoHV-1.

Dosage-dependent copy number gains in E2f1 and E2f3 drive hepatocellular carcinoma

NARCIS (Netherlands)

Kent, Lindsey N.; Bae, Sooin; Tsai, Shih-Yin; Tang, Xing; Srivastava, Arunima; Koivisto, Christopher; Martin, Chelsea K.; Ridolfi, Elisa; Miller, Grace C.; Zorko, Sarah M.; Plevris, Emilia; Hadjiyannis, Yannis; Perez, Miguel; Nolan, Eric; Kladney, Raleigh; Westendorp, Bart; de Bruin, Alain; Fernandez, Soledad; Rosol, Thomas J.; Pohar, Kamal S.; Pipas, James M.; Leone, Gustavo

2017-01-01

Disruption of the retinoblastoma (RB) tumor suppressor pathway, either through genetic mutation of upstream regulatory components or mutation of RB1 itself, is believed to be a required event in cancer. However, genetic alterations in the RB-regulated E2F family of transcription factors are

A Diverse Panel of Hepatitis C Virus Glycoproteins for Use in Vaccine Research Reveals Extremes of Monoclonal Antibody Neutralization Resistance.

Science.gov (United States)

Urbanowicz, Richard A; McClure, C Patrick; Brown, Richard J P; Tsoleridis, Theocharis; Persson, Mats A A; Krey, Thomas; Irving, William L; Ball, Jonathan K; Tarr, Alexander W

2015-12-23

Despite significant advances in the treatment of hepatitis C virus (HCV) infection, the need to develop preventative vaccines remains. Identification of the best vaccine candidates and evaluation of their performance in preclinical and clinical development will require appropriate neutralization assays utilizing diverse HCV isolates. We aimed to generate and characterize a panel of HCV E1E2 glycoproteins suitable for subsequent use in vaccine and therapeutic antibody testing. Full-length E1E2 clones were PCR amplified from patient-derived serum samples, cloned into an expression vector, and used to generate viral pseudoparticles (HCVpp). In addition, some of these clones were used to generate cell culture infectious (HCVcc) clones. The infectivity and neutralization sensitivity of these viruses were then determined. Bioinformatic and HCVpp infectivity screening of approximately 900 E1E2 clones resulted in the assembly of a panel of 78 functional E1E2 proteins representing distinct HCV genotypes and different stages of infection. These HCV glycoproteins differed markedly in their sensitivity to neutralizing antibodies. We used this panel to predict antibody efficacy against circulating HCV strains, highlighting the likely reason why some monoclonal antibodies failed in previous clinical trials. This study provides the first objective categorization of cross-genotype patient-derived HCV E1E2 clones according to their sensitivity to antibody neutralization. It has shown that HCV isolates have clearly distinguishable neutralization-sensitive, -resistant, or -intermediate phenotypes, which are independent of genotype. The panel provides a systematic means for characterization of the neutralizing response elicited by candidate vaccines and for defining the therapeutic potential of monoclonal antibodies. Hepatitis C virus (HCV) has a global burden of more than 170 million people, many of whom cannot attain the new, expensive, direct-acting antiviral therapies. A safe and

Recent Progress in Electrochemical Biosensors for Glycoproteins

Directory of Open Access Journals (Sweden)

Uichi Akiba

2016-12-01

Full Text Available This review provides an overview of recent progress in the development of electrochemical biosensors for glycoproteins. Electrochemical glycoprotein sensors are constructed by combining metal and carbon electrodes with glycoprotein-selective binding elements including antibodies, lectin, phenylboronic acid and molecularly imprinted polymers. A recent trend in the preparation of glycoprotein sensors is the successful use of nanomaterials such as graphene, carbon nanotube, and metal nanoparticles. These nanomaterials are extremely useful for improving the sensitivity of glycoprotein sensors. This review focuses mainly on the protocols for the preparation of glycoprotein sensors and the materials used. Recent improvements in glycoprotein sensors are discussed by grouping the sensors into several categories based on the materials used as recognition elements.

Glycoprotein 90K Promotes E-Cadherin Degradation in a Cell Density-Dependent Manner via Dissociation of E-Cadherin–p120-Catenin Complex

Directory of Open Access Journals (Sweden)

So-Yeon Park

2017-12-01

Full Text Available Glycoprotein 90K (also known as LGALS3BP or Mac-2BP is a tumor-associated protein, and high 90K levels are associated with poor prognosis in some cancers. To clarify the role of 90K as an indicator for poor prognosis and metastasis in epithelial cancers, the present study investigated the effect of 90K on an adherens junctional protein, E-cadherin, which is frequently absent or downregulated in human epithelial cancers. Treatment of certain cancer cells with 90K significantly reduced E-cadherin levels in a cell-population-dependent manner, and these cells showed decreases in cell adhesion and increases in invasive cell motility. Mechanistically, 90K-induced E-cadherin downregulation occurred via ubiquitination-mediated proteasomal degradation. 90K interacted with the E-cadherin–p120-catenin complex and induced its dissociation, altering the phosphorylation status of p120-catenin, whereas it did not associate with β-catenin. In subconfluent cells, 90K decreased membrane-localized p120-catenin and the membrane fraction of the p120-catenin. Particularly, 90K-induced E-cadherin downregulation was diminished in p120-catenin knocked-down cells. Taken together, 90K upregulation promotes the dissociation of the E-cadherin–p120-catenin complex, leading to E-cadherin proteasomal degradation, and thereby destabilizing adherens junctions in less confluent tumor cells. Our results provide a potential mechanism to explain the poor prognosis of cancer patients with high serum 90K levels.

Urinary Tract Effects of HPSE2 Mutations

OpenAIRE

Stuart, H; Roberts, N; Hilton, E; McKenzie, E; Daly, S; Hadfield, K; Rahal, J; Gardiner, N; Tanley, S; Lewis, M; Sites, E; Angle, B; Alves, C; Lourenço, T; Rodrigues, M

2015-01-01

Urofacial syndrome (UFS) is an autosomal recessive congenital disease featuring grimacing and incomplete bladder emptying. Mutations of HPSE2, encoding heparanase 2, a heparanase 1 inhibitor, occur in UFS, but knowledge about the HPSE2 mutation spectrum is limited. Here, seven UFS kindreds with HPSE2 mutations are presented, including one with deleted asparagine 254, suggesting a role for this amino acid, which is conserved in vertebrate orthologs. HPSE2 mutations were absent in 23 non-neurog...

Mutation analysis in the long isoform of USH2A in American patients with Usher Syndrome type II.

Science.gov (United States)

Yan, Denise; Ouyang, Xiaomei; Patterson, D Michael; Du, Li Lin; Jacobson, Samuel G; Liu, Xue-Zhong

2009-12-01

Usher syndrome type II (USH2) is an autosomal recessive disorder characterized by moderate to severe hearing impairment and progressive visual loss due to retinitis pigmentosa (RP). To identify novel mutations and determine the frequency of USH2A mutations as a cause of USH2, we have carried out mutation screening of all 72 coding exons and exon-intron splice sites of the USH2A gene. A total of 20 USH2 American probands of European descent were analyzed using single strand conformational polymorphism (SSCP) and direct sequencing methods. Ten different USH2A mutations were identified in 55% of the probands, five of which were novel mutations. The detected mutations include three missense, three frameshifts and four nonsense mutations, with c.2299delG/p.E767fs mutation, accounting for 38.9% of the pathological alleles. Two cases were homozygotes, two cases were compound heterozygotes and one case had complex allele with three variants. In seven probands, only one USH2A mutation was detected and no pathological mutation was found in the remaining eight individuals. Altogether, our data support the fact that c.2299delG/p.E767fs is indeed the most common USH2A mutation found in USH2 patients of European Caucasian background. Thus, if screening for mutations in USH2A is considered, it is reasonable to screen for the c.2299delG mutation first.

Association between nucleotide mutation of eNOS gene and serum ...

African Journals Online (AJOL)

Galaxy

2013-05-15

May 15, 2013 ... spasm among Japanese (Nakayama et al., 1999; Casas et al., 2006). It is believed that these mutations might result in altered NO metabolism and impaired .... ship between T-786C mutation of eNOS gene and CAD specifically in the Iranian population. To our knowledge, this polymorphism has never been ...

Herpes simplex virus (HSV)-specific proliferative and cytotoxic T-cell responses in humans immunized with an HSF type 2 glycoprotein subunit vaccine

Energy Technology Data Exchange (ETDEWEB)

Zarling, J.M.; Moran, P.A.; Brewer, L.; Ashley, R.; Corey, L.

1988-12-01

Studies were undertaken to determine whether immunization of humans with a herpes simplex virus type 2 (HSV-2) glycoprotein-subunit vaccine would result in the priming of both HSV-specific proliferating cells and cytotoxic T cells. Peripheral blood lymphocytes (PBL) from all eight vaccinees studied responded by proliferating after stimulation with HSV-2, HSV-1, and glycoprotein gB-1. The PBL of five of these eight vaccinees proliferated following stimulation with gD-2, whereas stimulation with Gd-1 resulted in relatively low or no proliferative responses. T-cell clones were generated from HSV-2-stimulated PBL of three vaccinees who demonstrated strong proliferative responses to HSV-1 and HSV-2. Of 12 clones studied in lymphoproliferative assays, 9 were found to be cross-reactive for HSV-1 and HSV-2. Of the approximately 90 T-cell clones isolated, 14 demonstrated HSV-specific cytotoxic activity. Radioimmunoprecipitation-polyacrylamide gel electrophoresis analyses confirmed that the vaccinees had antibodies only to HSV glycoproteins, not to proteins which are absent in the subunit vaccine, indicating that these vaccinees had not become infected with HSV. Immunization of humans with an HSV-2 glycoprotein-subunit vaccine thus results in the priming of T cells that proliferate in response to stimulation with HSV and its glycoproteins and T cells that have cytotoxic activity against HSV-infected cells. Such HSV-specific memory T cells were detected as late as 2 years following the last boost with the subunit vaccine.

TFAP2B mutation and dental anomalies.

Science.gov (United States)

Tanasubsinn, Natchaya; Sittiwangkul, Rekwan; Pongprot, Yupada; Kawasaki, Katsushige; Ohazama, Atsushi; Sastraruji, Thanapat; Kaewgahya, Massupa; Kantaputra, Piranit Nik

2017-08-01

Mutations inTFAP2B has been reported in patients with isolated patent ductus arteriosus (PDA) and Char syndrome. We performed mutation analysis of TFAP2B in 43 patients with isolated PDA, 7 patients with PDA with other congenital heart defects and 286 patients with isolated tooth agenesis with or without other dental anomalies. The heterozygous c.1006G>A mutation was identified in 20 individuals. Those mutation carriers consisted of 1 patient with term PDA (1/43), 16 patients with isolated tooth agenesis with or without other dental anomalies (16/286; 5.6%), 1 patient with PDA and severe valvular aortic stenosis and tooth agenesis (1/4) and 2 normal controls (2/100; 1%). The mutation is predicted to cause an amino-acid substitution p.Val336Ile in the TFAP2B protein. Tfap2b expression during early mouse tooth development supports the association of TFAP2B mutation and dental anomalies. It is hypothesized that this incidence might have been the result of founder effect. Here we report for the first time that TFAP2B mutation is associated with tooth agenesis, microdontia, supernumerary tooth and root maldevelopment. In addition, we also found that TFAP2B mutations, the common causes of PDA in Caucasian, are not the common cause of PDA in Thai population.

The membrane-proximal tryptophan-rich region in the transmembrane glycoprotein ectodomain of feline immunodeficiency virus is important for cell entry

International Nuclear Information System (INIS)

Giannecchini, Simone; Bonci, Francesca; Pistello, Mauro; Matteucci, Donatella; Sichi, Olimpia; Rovero, Paolo; Bendinelli, Mauro

2004-01-01

The mechanisms whereby feline immunodeficiency virus (FIV) adsorbs and enters into susceptible cells are poorly understood. Here, we investigated the role exerted in such functions by the tryptophan (Trp)-rich motif present membrane-proximally in the ectodomain of the FIV transmembrane glycoprotein. Starting from p34TF10, which encodes the entire genome of FIV Petaluma, we produced 11 mutated clones having the Trp-rich motif scrambled or variously deleted or substituted. All mutated progenies adsorbed normally to cells, but the ones with severe disruptions of the motif failed to generate proviral DNA. In the latter mutants, proviral DNA formation was restored by providing an independent source of intact FIV envelope glycoproteins or by addition of the fusing agent polyethylene glycol, thus clearly indicating that their defect resided primarily at the level of cell entry. In addition, the replication-competent mutants exhibited a generally enhanced susceptibility to selected entry inhibitory synthetic peptides, suggestive of a reduced efficiency of the entry step

CORRELATION BETWEEN CHEMOTHERAPY RESPONSE AND EXPRESSION PROFILES OF TRANSMEMBRANE PROTEINS: P-GLYCOPROTEIN (ABCB1, MRP2 (ABCC2, BCRP (ABCG2 IN PATIENTS WITH INVASIVE BREAST CANCER

Directory of Open Access Journals (Sweden)

К. Yu. Khristenko

2016-01-01

Full Text Available Overexpression of ABC drug transporters can cause multidrug resistance (MDR in cancer cells, which is a major obstacle in the success of cancer chemotherapy. Our study revealed a correlation between the expression of invasive breast cancer resistance-associated proteins, such as P-glycoprotein (ABCB1, MRP2 (ABCC2, BCRP (ABCG2 in tumor cells and pathologic response to neoadjuvant chemotherapy. The response to neoadjuvant chemotherapy was shown to be associated with a lack of BCRP expression in tumor cells. The pathologic tumor response was correlated with the presence of positive MRP2 expression and the expression level of P-glycoprotein in cells of invasive breast cancer. 

Interaction of CSFV E2 protein with swine host factors as detected by yeast two-hybrid system

Science.gov (United States)

E2 is one of the envelope glycoproteins of pestiviruses, including classical swine fever virus (CSFV) and bovine viral diarrhea virus (BVDV). E2 is involved in several critical functions, including virus entry into target cells, induction of a protective immune response and virulence in swine. Howev...

Imputation of the rare HOXB13 G84E mutation and cancer risk in a large population-based cohort.

Directory of Open Access Journals (Sweden)

Thomas J Hoffmann

2015-01-01

Full Text Available An efficient approach to characterizing the disease burden of rare genetic variants is to impute them into large well-phenotyped cohorts with existing genome-wide genotype data using large sequenced referenced panels. The success of this approach hinges on the accuracy of rare variant imputation, which remains controversial. For example, a recent study suggested that one cannot adequately impute the HOXB13 G84E mutation associated with prostate cancer risk (carrier frequency of 0.0034 in European ancestry participants in the 1000 Genomes Project. We show that by utilizing the 1000 Genomes Project data plus an enriched reference panel of mutation carriers we were able to accurately impute the G84E mutation into a large cohort of 83,285 non-Hispanic White participants from the Kaiser Permanente Research Program on Genes, Environment and Health Genetic Epidemiology Research on Adult Health and Aging cohort. Imputation authenticity was confirmed via a novel classification and regression tree method, and then empirically validated analyzing a subset of these subjects plus an additional 1,789 men from Kaiser specifically genotyped for the G84E mutation (r2 = 0.57, 95% CI = 0.37–0.77. We then show the value of this approach by using the imputed data to investigate the impact of the G84E mutation on age-specific prostate cancer risk and on risk of fourteen other cancers in the cohort. The age-specific risk of prostate cancer among G84E mutation carriers was higher than among non-carriers. Risk estimates from Kaplan-Meier curves were 36.7% versus 13.6% by age 72, and 64.2% versus 24.2% by age 80, for G84E mutation carriers and non-carriers, respectively (p = 3.4x10-12. The G84E mutation was also associated with an increase in risk for the fourteen other most common cancers considered collectively (p = 5.8x10-4 and more so in cases diagnosed with multiple cancer types, both those including and not including prostate cancer, strongly suggesting

The Escherichia coli modE gene: effect of modE mutations on molybdate dependent modA expression.

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McNicholas, P M; Chiang, R C; Gunsalus, R P

1996-11-15

The Escherichia coli modABCD operon, which encodes a high-affinity molybdate uptake system, is transcriptionally regulated in response to molybdate availability by ModE. Here we describe a highly effective enrichment protocol, applicable to any gene with a repressor role, and establish its application in the isolation of transposon mutations in modE. In addition we show that disruption of the ModE C-terminus abolishes derepression in the absence of molybdate, implying this region of ModE controls the repressor activity. Finally, a mutational analysis of a proposed molybdate binding motif indicates that this motif does not function in regulating the repressor activity of ModE.

Activating HER2 mutations in HER2 gene amplification negative breast cancer.

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Bose, Ron; Kavuri, Shyam M; Searleman, Adam C; Shen, Wei; Shen, Dong; Koboldt, Daniel C; Monsey, John; Goel, Nicholas; Aronson, Adam B; Li, Shunqiang; Ma, Cynthia X; Ding, Li; Mardis, Elaine R; Ellis, Matthew J

2013-02-01

Data from 8 breast cancer genome-sequencing projects identified 25 patients with HER2 somatic mutations in cancers lacking HER2 gene amplification. To determine the phenotype of these mutations, we functionally characterized 13 HER2 mutations using in vitro kinase assays, protein structure analysis, cell culture, and xenograft experiments. Seven of these mutations are activating mutations, including G309A, D769H, D769Y, V777L, P780ins, V842I, and R896C. HER2 in-frame deletion 755-759, which is homologous to EGF receptor (EGFR) exon 19 in-frame deletions, had a neomorphic phenotype with increased phosphorylation of EGFR or HER3. L755S produced lapatinib resistance, but was not an activating mutation in our experimental systems. All of these mutations were sensitive to the irreversible kinase inhibitor, neratinib. These findings show that HER2 somatic mutation is an alternative mechanism to activate HER2 in breast cancer and they validate HER2 somatic mutations as drug targets for breast cancer treatment. We show that the majority of HER2 somatic mutations in breast cancer patients are activating mutations that likely drive tumorigenesis. Several patients had mutations that are resistant to the reversible HER2 inhibitor lapatinib, but are sensitive to the irreversible HER2 inhibitor, neratinib. Our results suggest that patients with HER2 mutation–positive breast cancers could benefit from existing HER2-targeted drugs.

Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 2; referees: 2 approved

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Bryony Jenkins

2017-02-01

Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of pMHC formation or TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

Glycoprotein cytoplasmic domain sequences required for rescue of a vesicular stomatitis virus glycoprotein mutant

International Nuclear Information System (INIS)

Whitt, M.A.; Chong, L.; Rose, J.K.

1989-01-01

The authors have used transient expression of the wild-type vesicular stomatitis virus (VSV) glycoprotein (G protein) from cloned cDNA to rescue a temperature-sensitive G protein mutant of VSV in cells at the nonpermissive temperature. Using cDNAs encoding G proteins with deletions in the normal 29-amino-acid cytoplasmic domain, they determined that the presence of either the membrane-proximal 9 amino acids or the membrane-distal 12 amino acids was sufficient for rescue of the temperature-sensitive mutant. G proteins with cytoplasmic domains derived from other cellular or viral G proteins did not rescue the mutant, nor did G proteins with one or three amino acids of the normal cytoplasmic domain. Rescue correlated directly with the ability of the G proteins to be incorporated into virus particles. This was shown by analysis of radiolabeled particles separated on sucrose gradients as well as by electron microscopy of rescued virus after immunogold labeling. Quantitation of surface expression showed that all of the mutated G proteins were expressed less efficiently on the cell surface than was wild-type G protein. However, they were able to correct for differences in rescue efficiency resulting from differences in the level of surface expression by reducing wild-type G protein expression to levels equivalent to those observed for the mutated G proteins. The results provide evidence that at least a portion of the cytoplasmic domain is required for efficient assembly of the VSV G protein into virions during virus budding

Potential relationship between Hashimoto's thyroiditis and BRAF(V600E) mutation status in papillary thyroid cancer.

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Zeng, Rui-Chao; Jin, Lang-Ping; Chen, En-Dong; Dong, Si-Yang; Cai, Ye-Feng; Huang, Guan-Li; Li, Quan; Jin, Chun; Zhang, Xiao-Hua; Wang, Ou-Chen

2016-04-01

The purpose of this study was to evaluate the potential relationship between Hashimoto's thyroiditis and BRAF(V600E) mutation status in patients with papillary thyroid carcinoma (PTC). A total of 619 patients with PTC who underwent total thyroidectomy with lymph node dissection were enrolled in this study. Univariable and multivariate analyses were used. Hashimoto's thyroiditis was present in 35.9% (222 of 619) of PTCs. Multivariate logistic regressions showed that BRAF(V600E) mutation, sex, extrathyroidal extension, and lymph node metastasis were independent factors for Hashimoto's thyroiditis. Female sex, more frequent extrathyroidal extension, and a higher incidence of lymph node metastasis were significantly associated with PTCs accompanied by BRAF(V600E) mutation without Hashimoto's thyroiditis compared with PTCs accompanied by BRAF(V600E) mutation with Hashimoto's thyroiditis. Hashimoto's thyroiditis was negatively associated with BRAF(V600E) mutation, extrathyroidal extension, and lymph node metastasis. In addition, Hashimoto's thyroiditis was related to less lymph node metastasis and extrathyroidal extension in PTCs with BRAF(V600E) mutation. Therefore, Hashimoto's thyroiditis is a potentially protective factor in PTC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1019-E1025, 2016. © 2015 Wiley Periodicals, Inc.

Regulation of glycoprotein synthesis in yeast by mating pheromones

International Nuclear Information System (INIS)

Tanner, W.

1984-01-01

In Saccharomyces cerevisiae, glycosylated proteins amount to less than 2% of the cell protein. Two intensively studied examples of yeast glycoproteins are the external cell wall - associated invertase and the vacuolar carboxypeptidase Y. Recently, it was shown that the mating pheromone, alpha factor, specifically and strongly inhibits the synthesis of N-glycosylated proteins in haploid a cells, whereas O-glycosylated proteins are not affected. In this paper, the pathways of glycoprotein biosynthesis are summarized briefly, and evidence is presented that mating pheomones have a regulatory function in glycoprotein synthesis

New insights into the Hendra virus attachment and entry process from structures of the virus G glycoprotein and its complex with Ephrin-B2.

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Kai Xu

Full Text Available Hendra virus and Nipah virus, comprising the genus Henipavirus, are recently emerged, highly pathogenic and often lethal zoonotic agents against which there are no approved therapeutics. Two surface glycoproteins, the attachment (G and fusion (F, mediate host cell entry. The crystal structures of the Hendra G glycoprotein alone and in complex with the ephrin-B2 receptor reveal that henipavirus uses Tryptophan 122 on ephrin-B2/B3 as a "latch" to facilitate the G-receptor association. Structural-based mutagenesis of residues in the Hendra G glycoprotein at the receptor binding interface document their importance for viral attachments and entry, and suggest that the stability of the Hendra-G-ephrin attachment complex does not strongly correlate with the efficiency of viral entry. In addition, our data indicates that conformational rearrangements of the G glycoprotein head domain upon receptor binding may be the trigger leading to the activation of the viral F fusion glycoprotein during virus infection.

A Functional Henipavirus Envelope Glycoprotein Pseudotyped Lentivirus Assay System

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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

Induction of anti-β2 -glycoprotein I autoantibodies in mice by protein H of Streptococcus pyogenes

NARCIS (Netherlands)

van O S, G. M. A.; Meijers, J. C. M.; Agar, Ç; Valls Seron, M.; Marquart, J. A.; Åkesson, P.; Urbanus, R. T.; Derksen, R. H. W. M.; Herwald, H.; Mörgelin, M.; D E Groot, P. G.

2011-01-01

The antiphospholipid syndrome (APS) is characterized by the persistent presence of anti-β(2) -glycoprotein I (β(2) -GPI) autoantibodies. β(2) -GPI can exist in two conformations. In plasma it is a circular protein, whereas it adopts a fish-hook conformation after binding to phospholipids. Only the

Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations.

Science.gov (United States)

Szpurka, Hadrian; Jankowska, Anna M; Makishima, Hideki; Bodo, Juraj; Bejanyan, Nelli; Hsi, Eric D; Sekeres, Mikkael A; Maciejewski, Jaroslaw P

2010-08-01

While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation was present in one mutated TET2 and ASXL1 case. JAK2V617F/MPLW515L mutations were absent in TET2/ASXL1 mutants, indicating that similar clinical phenotype can be produced by various MPN-associated mutations and that additional unifying lesions may be present in RARS-T. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Flow cytometric analysis of platelet cyclooxygenase-1 and -2 and surface glycoproteins in patients with immune thrombocytopenia and healthy individuals.

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Rubak, Peter; Kristensen, Steen D; Hvas, Anne-Mette

2017-06-01

Immature platelets may contain more platelet enzymes such as cyclooxygenase (COX)-1 and COX-2 than mature platelets. Patients with immune thrombocytopenia (ITP) have a higher fraction of immature platelets and can therefore be utilized as a biological model for investigating COX-1 and COX-2 platelet expression. The aims were to develop flow cytometric assays for platelet COX-1 and COX-2 and to investigate the COX-1 and COX-2 platelet expression, platelet turnover, and platelet glycoproteins in ITP patients (n = 10) compared with healthy individuals (n = 30). Platelet count and platelet turnover parameters (mean platelet volume (MPV), immature platelet fraction (IPF), and immature platelet count (IPC)) were measured by flow cytometry (Sysmex XE-5000). Platelet COX-1, COX-2, and the glycoproteins (GP)IIb, IX, Ib, Ia, and IIIa were all analyzed by flow cytometry (Navios) and expressed as median fluorescence intensity. COX analyses were performed in both whole blood and platelet rich plasma (PRP), whereas platelet glycoproteins were analyzed in whole blood only. ITP patients had significantly lower platelet count (55 × 10 9 /L) than healthy individuals (240 × 10 9 /L, p platelet count and IPC (both p-values Platelet COX-1 expression was higher in ITP patients than healthy individuals using whole blood (p COX-1 platelet turnover and COX-1 expression (all p-values platelet turnover and COX-1 and COX-2 expressions (all p-values platelet turnover in ITP patients (all p-values 0.14, rho = 0.11-0.28). In conclusion, ITP patients expressed higher COX-1 and platelet glycoprotein levels than healthy individuals. COX-1 and platelet glycoproteins demonstrated positive correlations with platelet turnover in ITP patients. In healthy individuals, COX-1 and COX-2 expression correlated positively with platelet turnover. PRP was more sensitive compared with whole blood as regards determination of COX. Therefore, PRP is the recommended matrix for investigating COX-1 and COX-2 in

Labelled antibody techniques in glycoprotein estimation

International Nuclear Information System (INIS)

Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

1977-01-01

The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

Intraspecific bovine herpesvirus 1 recombinants carrying glycoprotein E deletion as a vaccine marker are virulent in cattle.

Science.gov (United States)

Muylkens, Benoît; Meurens, François; Schynts, Frédéric; Farnir, Frédéric; Pourchet, Aldo; Bardiau, Marjorie; Gogev, Sacha; Thiry, Julien; Cuisenaire, Adeline; Vanderplasschen, Alain; Thiry, Etienne

2006-08-01

Vaccines used in control programmes of Bovine herpesvirus 1 (BoHV-1) utilize highly attenuated BoHV-1 strains marked by a deletion of the glycoprotein E (gE) gene. Since BoHV-1 recombinants are obtained at high frequency in experimentally coinfected cattle, the consequences of recombination on the virulence of gE-negative BoHV-1 were investigated. Thus, gE-negative BoHV-1 recombinants were generated in vitro from several virulent BoHV-1 and one mutant BoHV-1 deleted in the gC and gE genes. Four gE-negative recombinants were tested in the natural host. All the recombinants were more virulent than the gE-negative BoHV-1 vaccine and the gC- and gE-negative parental BoHV-1. The gE-negative recombinant isolated from a BoHV-1 field strain induced the highest severe clinical score. Latency and reactivation studies showed that three of the recombinants were reexcreted. Recombination can therefore restore virulence of gE-negative BoHV-1 by introducing the gE deletion into a different virulence background.

Identification of novel driver mutations of the discoidin domain receptor 2 (DDR2) gene in squamous cell lung cancer of Chinese patients

International Nuclear Information System (INIS)

Miao, Liyun; Zhang, Deping; Liu, Hongbing; Song, Yong; Wang, Yongsheng; Zhu, Suhua; Shi, Minke; Li, Yan; Ding, Jingjing; Yang, Jun; Ye, Qing; Cai, Hourong

2014-01-01

Although many of the recently approved genomically targeted therapies have improved outcomes for patients in non–small-cell lung cancer (NSCLC) with lung adenocarcinoma, little is known about the genomic alterations that drive lung squamous cell cancer (SCC) and development of effective targeted therapies in lung SCC is a promising area to be further investigated. Discoidin domain receptor 2 (DDR2), is a novel receptor tyrosine kinases that respond to several collagens and involved in tissue repair, primary and metastatic cancer progression. Expression of DDR2 mRNA was analyzed in 54 lung SCC tissues by qRT-PCR. Over-expression approaches were used to investigate the biological functions of DDR2 and its’ mutations in lung SCC cells. Conventional Sanger sequencing was used to investigate the mutations of DDR2 gene in 86 samples. The effect of DDR2 and its’ mutations on proliferation was evaluated by MTT and colony formation assays; cell migration and invasion was evaluated by trasnwell assays. Lung SCC cells stably transfected with pEGFP-DDR2 WT, pEGFP-DDR2-S131C or empty vector were injection into nude mice to study the effect of DDR2 and its’ mutation on tumorigenesis in vivo. Protein and mRNA expression levels of E-cadherin and MMP2 were determined by qRT-PCR and western blot analysis. Differences between groups were tested for significance using Student’s t-test (two-tailed). In this study, we found that DDR2 mRNA levels were significantly decreased in 54 lung SCC tissues compared with normal lung tissues. Moreover, there were 3 novel DDR2 mutations (G531V, S131C, T681I) in 4 patients and provide the mutation rate of 4.6% in the 86 patients with lung SCC. The mutation of S131C in DDR2 could promote lung SCC cells proliferation, migration and invasion via inducing MMP-2, but reducing E-cadherin expression. These data indicated that the novel DDR2 mutation may contribute to the development and progression of lung SCC and this effect may be associated

eIF2β is critical for eIF5-mediated GDP-dissociation inhibitor activity and translational control.

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Jennings, Martin D; Kershaw, Christopher J; White, Christopher; Hoyle, Danielle; Richardson, Jonathan P; Costello, Joseph L; Donaldson, Ian J; Zhou, Yu; Pavitt, Graham D

2016-11-16

In protein synthesis translation factor eIF2 binds initiator tRNA to ribosomes and facilitates start codon selection. eIF2 GDP/GTP status is regulated by eIF5 (GAP and GDI functions) and eIF2B (GEF and GDF activities), while eIF2α phosphorylation in response to diverse signals is a major point of translational control. Here we characterize a growth suppressor mutation in eIF2β that prevents eIF5 GDI and alters cellular responses to reduced eIF2B activity, including control of GCN4 translation. By monitoring the binding of fluorescent nucleotides and initiator tRNA to purified eIF2 we show that the eIF2β mutation does not affect intrinsic eIF2 affinities for these ligands, neither does it interfere with eIF2 binding to 43S pre-initiation complex components. Instead we show that the eIF2β mutation prevents eIF5 GDI stabilizing nucleotide binding to eIF2, thereby altering the off-rate of GDP from eIF2•GDP/eIF5 complexes. This enables cells to grow with reduced eIF2B GEF activity but impairs activation of GCN4 targets in response to amino acid starvation. These findings provide support for the importance of eIF5 GDI activity in vivo and demonstrate that eIF2β acts in concert with eIF5 to prevent premature release of GDP from eIF2γ and thereby ensure tight control of protein synthesis initiation. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Cleavage of a Neuroinvasive Human Respiratory Virus Spike Glycoprotein by Proprotein Convertases Modulates Neurovirulence and Virus Spread within the Central Nervous System.

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Alain Le Coupanec

Full Text Available Human coronaviruses (HCoV are respiratory pathogens that may be associated with the development of neurological diseases, in view of their neuroinvasive and neurotropic properties. The viral spike (S glycoprotein is a major virulence factor for several coronavirus species, including the OC43 strain of HCoV (HCoV-OC43. In an attempt to study the role of this protein in virus spread within the central nervous system (CNS and neurovirulence, as well as to identify amino acid residues important for such functions, we compared the sequence of the S gene found in the laboratory reference strain HCoV-OC43 ATCC VR-759 to S sequences of viruses detected in clinical isolates from the human respiratory tract. We identified one predominant mutation at amino acid 758 (from RRSR↓ G758 to RRSR↓R758, which introduces a putative furin-like cleavage (↓ site. Using a molecular cDNA infectious clone to generate a corresponding recombinant virus, we show for the first time that such point mutation in the HCoV-OC43 S glycoprotein creates a functional cleavage site between the S1 and S2 portions of the S protein. While the corresponding recombinant virus retained its neuroinvasive properties, this mutation led to decreased neurovirulence while potentially modifying the mode of virus spread, likely leading to a limited dissemination within the CNS. Taken together, these results are consistent with the adaptation of HCoV-OC43 to the CNS environment, resulting from the selection of quasi-species harboring mutations that lead to amino acid changes in viral genes, like the S gene in HCoV-OC43, which may contribute to a more efficient establishment of a less pathogenic but persistent CNS infection. This adaptative mechanism could potentially be associated with human encephalitis or other neurological degenerative pathologies.

Glucokinase gene mutations (MODY 2) in Asian Indians.

Science.gov (United States)

Kanthimathi, Sekar; Jahnavi, Suresh; Balamurugan, Kandasamy; Ranjani, Harish; Sonya, Jagadesan; Goswami, Soumik; Chowdhury, Subhankar; Mohan, Viswanathan; Radha, Venkatesan

2014-03-01

Heterozygous inactivating mutations in the glucokinase (GCK) gene cause a hyperglycemic condition termed maturity-onset diabetes of the young (MODY) 2 or GCK-MODY. This is characterized by mild, stable, usually asymptomatic, fasting hyperglycemia that rarely requires pharmacological intervention. The aim of the present study was to screen for GCK gene mutations in Asian Indian subjects with mild hyperglycemia. Of the 1,517 children and adolescents of the population-based ORANGE study in Chennai, India, 49 were found to have hyperglycemia. These children along with the six patients referred to our center with mild hyperglycemia were screened for MODY 2 mutations. The GCK gene was bidirectionally sequenced using BigDye(®) Terminator v3.1 (Applied Biosystems, Foster City, CA) chemistry. In silico predictions of the pathogenicity were carried out using the online tools SIFT, Polyphen-2, and I-Mutant 2.0 software programs. Direct sequencing of the GCK gene in the patients referred to our Centre revealed one novel mutation, Thr206Ala (c.616A>G), in exon 6 and one previously described mutation, Met251Thr (c.752T>C), in exon 7. In silico analysis predicted the novel mutation to be pathogenic. The highly conserved nature and critical location of the residue Thr206 along with the clinical course suggests that the Thr206Ala is a MODY 2 mutation. However, we did not find any MODY 2 mutations in the 49 children selected from the population-based study. Hence prevalence of GCK mutations in Chennai is MODY 2 mutations from India and confirms the importance of considering GCK gene mutation screening in patients with mild early-onset hyperglycemia who are negative for β-cell antibodies.

Whole-exome sequencing identifies novel MPL and JAK2 mutations in triple-negative myeloproliferative neoplasms.

Science.gov (United States)

Milosevic Feenstra, Jelena D; Nivarthi, Harini; Gisslinger, Heinz; Leroy, Emilie; Rumi, Elisa; Chachoua, Ilyas; Bagienski, Klaudia; Kubesova, Blanka; Pietra, Daniela; Gisslinger, Bettina; Milanesi, Chiara; Jäger, Roland; Chen, Doris; Berg, Tiina; Schalling, Martin; Schuster, Michael; Bock, Christoph; Constantinescu, Stefan N; Cazzola, Mario; Kralovics, Robert

2016-01-21

Essential thrombocythemia (ET) and primary myelofibrosis (PMF) are chronic diseases characterized by clonal hematopoiesis and hyperproliferation of terminally differentiated myeloid cells. The disease is driven by somatic mutations in exon 9 of CALR or exon 10 of MPL or JAK2-V617F in >90% of the cases, whereas the remaining cases are termed "triple negative." We aimed to identify the disease-causing mutations in the triple-negative cases of ET and PMF by applying whole-exome sequencing (WES) on paired tumor and control samples from 8 patients. We found evidence of clonal hematopoiesis in 5 of 8 studied cases based on clonality analysis and presence of somatic genetic aberrations. WES identified somatic mutations in 3 of 8 cases. We did not detect any novel recurrent somatic mutations. In 3 patients with clonal hematopoiesis analyzed by WES, we identified a somatic MPL-S204P, a germline MPL-V285E mutation, and a germline JAK2-G571S variant. We performed Sanger sequencing of the entire coding region of MPL in 62, and of JAK2 in 49 additional triple-negative cases of ET or PMF. New somatic (T119I, S204F, E230G, Y591D) and 1 germline (R321W) MPL mutation were detected. All of the identified MPL mutations were gain-of-function when analyzed in functional assays. JAK2 variants were identified in 5 of 57 triple-negative cases analyzed by WES and Sanger sequencing combined. We could demonstrate that JAK2-V625F and JAK2-F556V are gain-of-function mutations. Our results suggest that triple-negative cases of ET and PMF do not represent a homogenous disease entity. Cases with polyclonal hematopoiesis might represent hereditary disorders. © 2016 by The American Society of Hematology.

Quantitative Characterization of E-selectin Interaction with Native CD44 and P-selectin Glycoprotein Ligand-1 (PSGL-1) Using a Real Time Immunoprecipitation-based Binding Assay

KAUST Repository

Abu Samra, Dina Bashir Kamil; Al Kilani, Alia; Hamdan, Samir; Sakashita, Kosuke; Gadhoum, Samah Z.; Merzaban, Jasmeen

2015-01-01

Selectins (E-, P-, and L-selectins) interact with glycoprotein ligands to mediate the essential tethering/rolling step in cell transport and delivery that captures migrating cells from the circulating flow. In this work, we developed a real time immunoprecipitation assay on a surface plasmon resonance chip that captures native glycoforms of two well known E-selectin ligands (CD44/hematopoietic cell E-/L-selectin ligand and P-selectin glycoprotein ligand-1) from hematopoietic cell extracts. Here we present a comprehensive characterization of their binding to E-selectin. We show that both ligands bind recombinant monomeric E-selectin transiently with fast on- and fast off-rates, whereas they bind dimeric E-selectin with remarkably slow onand off-rates. This binding requires the sialyl Lewis x sugar moiety to be placed on both O- and N-glycans, and its association, but not dissociation, is sensitive to the salt concentration. Our results suggest a mechanism through which monomeric selectins mediate initial fast on and fast off kinetics to help capture cells out of the circulating shear flow; subsequently, tight binding by dimeric/oligomeric selectins is enabled to significantly slow rolling. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Quantitative Characterization of E-selectin Interaction with Native CD44 and P-selectin Glycoprotein Ligand-1 (PSGL-1) Using a Real Time Immunoprecipitation-based Binding Assay

KAUST Repository

Abu Samra, Dina Bashir Kamil

2015-06-29

Selectins (E-, P-, and L-selectins) interact with glycoprotein ligands to mediate the essential tethering/rolling step in cell transport and delivery that captures migrating cells from the circulating flow. In this work, we developed a real time immunoprecipitation assay on a surface plasmon resonance chip that captures native glycoforms of two well known E-selectin ligands (CD44/hematopoietic cell E-/L-selectin ligand and P-selectin glycoprotein ligand-1) from hematopoietic cell extracts. Here we present a comprehensive characterization of their binding to E-selectin. We show that both ligands bind recombinant monomeric E-selectin transiently with fast on- and fast off-rates, whereas they bind dimeric E-selectin with remarkably slow onand off-rates. This binding requires the sialyl Lewis x sugar moiety to be placed on both O- and N-glycans, and its association, but not dissociation, is sensitive to the salt concentration. Our results suggest a mechanism through which monomeric selectins mediate initial fast on and fast off kinetics to help capture cells out of the circulating shear flow; subsequently, tight binding by dimeric/oligomeric selectins is enabled to significantly slow rolling. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

A new human NHERF1 mutation decreases renal phosphate transporter NPT2a expression by a PTH-independent mechanism.

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Marie Courbebaisse

Full Text Available BACKGROUND: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1 binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. METHODS: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. RESULTS: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. CONCLUSIONS: Our results indicate that the PDZ1 domain is critical for NHERF1-NPT2a interaction in humans and for the control of NPT2a expression at the plasma membrane. Thus we have identified a new mechanism of renal phosphate loss and shown that different mutations in NHERF1 can alter renal phosphate reabsorption via distinct mechanisms.

Glycoprotein biosynthesis by human normal platelets

International Nuclear Information System (INIS)

Rodriguez, P.; Bello, O.; Apitz-Castro, R.

1987-01-01

Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation

Recently Identified Mutations in the Ebola Virus-Makona Genome Do Not Alter Pathogenicity in Animal Models

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Andrea Marzi

2018-05-01

Full Text Available Summary: Ebola virus (EBOV, isolate Makona, the causative agent of the West African EBOV epidemic, has been the subject of numerous investigations to determine the genetic diversity and its potential implication for virus biology, pathogenicity, and transmissibility. Despite various mutations that have emerged over time through multiple human-to-human transmission chains, their biological relevance remains questionable. Recently, mutations in the glycoprotein GP and polymerase L, which emerged and stabilized early during the outbreak, have been associated with improved viral fitness in cell culture. Here, we infected mice and rhesus macaques with EBOV-Makona isolates carrying or lacking those mutations. Surprisingly, all isolates behaved very similarly independent of the genotype, causing severe or lethal disease in mice and macaques, respectively. Likewise, we could not detect any evidence for differences in virus shedding. Thus, no specific biological phenotype could be associated with these EBOV-Makona mutations in two animal models. : Marzi et al. demonstrate that recently identified mutations in the EBOV-Makona genome, which appeared during the West African epidemic, do not significantly alter pathogenicity in IFNAR−/− mice and rhesus macaques. Other factors may have been more important for increased case numbers, case fatalities, and human-to-human transmission during this unprecedented epidemic. Keywords: Ebola virus, Ebola Makona, glycoprotein GP, polymerase L, GP mutation A82V, L mutation D759G, West African epidemic, pathogenicity

Crystallization and preliminary X-ray analysis of Chandipura virus glycoprotein G

International Nuclear Information System (INIS)

Baquero, Eduard; Buonocore, Linda; Rose, John K.; Bressanelli, Stéphane; Gaudin, Yves; Albertini, Aurélie A.

2012-01-01

Chandipura virus glycoprotein ectodomain (Gth) was purified and crystallized at pH 7.5. X-ray diffraction data set was collected to a resolution of 3.1 Å. Fusion in members of the Rhabdoviridae virus family is mediated by the G glycoprotein. At low pH, the G glycoprotein catalyzes fusion between viral and endosomal membranes by undergoing a major conformational change from a pre-fusion trimer to a post-fusion trimer. The structure of the G glycoprotein from vesicular stomatitis virus (VSV G), the prototype of Vesiculovirus, has recently been solved in its trimeric pre-fusion and post-fusion conformations; however, little is known about the structural details of the transition. In this work, a soluble form of the ectodomain of Chandipura virus G glycoprotein (CHAV G th ) was purified using limited proteolysis of purified virus; this soluble ectodomain was also crystallized. This protein shares 41% amino-acid identity with VSV G and thus its structure could provide further clues about the structural transition of rhabdoviral glycoproteins induced by low pH. Crystals of CHAV G th obtained at pH 7.5 diffracted X-rays to 3.1 Å resolution. These crystals belonged to the orthorhombic space group P2 1 2 1 2, with unit-cell parameters a = 150.3, b = 228.2, c = 78.8 Å. Preliminary analysis of the data based on the space group and the self-rotation function indicated that there was no trimeric association of the protomers. This unusual oligomeric status could result from the presence of fusion intermediates in the crystal

Recurrent and founder mutations in the PMS2 gene.

Science.gov (United States)

Tomsic, J; Senter, L; Liyanarachchi, S; Clendenning, M; Vaughn, C P; Jenkins, M A; Hopper, J L; Young, J; Samowitz, W; de la Chapelle, A

2013-03-01

Germline mutations in PMS2 are associated with Lynch syndrome (LS), the most common known cause of hereditary colorectal cancer. Mutation detection in PMS2 has been difficult due to the presence of several pseudogenes, but a custom-designed long-range PCR strategy now allows adequate mutation detection. Many mutations are unique. However, some mutations are observed repeatedly across individuals not known to be related due to the mutation being either recurrent, arising multiple times de novo at hot spots for mutations, or of founder origin, having occurred once in an ancestor. Previously, we observed 36 distinct mutations in a sample of 61 independently ascertained Caucasian probands of mixed European background with PMS2 mutations. Eleven of these mutations were detected in more than one individual not known to be related and of these, six were detected more than twice. These six mutations accounted for 31 (51%) ostensibly unrelated probands. Here, we performed genotyping and haplotype analysis in four mutations observed in multiple probands and found two (c.137G>T and exon 10 deletion) to be founder mutations and one (c.903G>T) a probable founder. One (c.1A>G) could not be evaluated for founder mutation status. We discuss possible explanations for the frequent occurrence of founder mutations in PMS2. © 2012 John Wiley & Sons A/S.

Histochemical and structural analysis of mucous glycoprotein secreted by the gill of Mytilus edulis

International Nuclear Information System (INIS)

Ahn, Hae-Young.

1988-01-01

Studies were carried out to characterized various mucous cells in the gill filament, to ascertain structural characteristics of the secreted mucous glycoproteins, and to determine the ability of the gill epithelium to incorporate [ 14 C]glucosamine as a precursor in the biosynthesis and secretion of mucous glycoproteins. Using histochemical staining techniques, mucous cells containing neutral and acidic mucins were found in the lateral region, whereas mucous cells containing primarily neutral or sulfated mucins were found in the postlateral region. Serotonin, but not dopamine, stimulated the mucous secretion. In tissues pretreated with [ 14 C]glucosamine, the secreted glycoproteins contain incorporated radiolabel. Analysis by column chromatography using Bio-Gel P-2 and P-6 shows that the secretion contains two glycoprotein populations. Glycoprotein II has a molecular weight of 2.3 x 10 4 daltons. Upon alkaline reductive borohydride cleavage of the O-glycosidic linkages of glycoprotein I, about 70% of the radiolabel was removed from the protein. Gas chromatographic analysis of the carbohydrate composition shows that the glycoproteins contains N-acetylglucosamine (GluNAc), N-acetylgalactosamine (GalNAc), and galactose, fucose and mannose. Amino acid analysis shows that the glycoproteins are rich in serine, threonine and proline

Glycoproteins and protein glycations identified in barley grain and malt by 2D-HPLC

Czech Academy of Sciences Publication Activity Database

Žídková, Jitka; Petry-Podgorska, Inga; Laštovičková, Markéta; Bobálová, Janette

2013-01-01

Roč. 20, č. 1 (2013), s. 43 ISSN 1211-5894. [Discussion in Structural Molecular Biology /11./. 14.03.2013-16.03.2013, Nové Hrady] R&D Projects: GA ČR(CZ) GPP503/12/P395 Institutional support: RVO:68081715 Keywords : barley grain * glycoproteins * 2D-HPLC * MS/MS Subject RIV: CB - Analytical Chemistry, Separation

Mutation in LIM2 Is Responsible for Autosomal Recessive Congenital Cataracts.

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Bushra Irum

Full Text Available To identify the molecular basis of non-syndromic autosomal recessive congenital cataracts (arCC in a consanguineous family.All family members participating in the study received a comprehensive ophthalmic examination to determine their ocular phenotype and contributed a blood sample, from which genomic DNA was extracted. Available medical records and interviews with the family were used to compile the medical history of the family. The symptomatic history of the individuals exhibiting cataracts was confirmed by slit-lamp biomicroscopy. A genome-wide linkage analysis was performed to localize the disease interval. The candidate gene, LIM2 (lens intrinsic membrane protein 2, was sequenced bi-directionally to identify the disease-causing mutation. The physical changes caused by the mutation were analyzed in silico through homology modeling, mutation and bioinformatic algorithms, and evolutionary conservation databases. The physiological importance of LIM2 to ocular development was assessed in vivo by real-time expression analysis of Lim2 in a mouse model.Ophthalmic examination confirmed the diagnosis of nuclear cataracts in the affected members of the family; the inheritance pattern and cataract development in early infancy indicated arCC. Genome-wide linkage analysis localized the critical interval to chromosome 19q with a two-point logarithm of odds (LOD score of 3.25. Bidirectional sequencing identified a novel missense mutation, c.233G>A (p.G78D in LIM2. This mutation segregated with the disease phenotype and was absent in 192 ethnically matched control chromosomes. In silico analysis predicted lower hydropathicity and hydrophobicity but higher polarity of the mutant LIM2-encoded protein (MP19 compared to the wild-type. Moreover, these analyses predicted that the mutation would disrupt the secondary structure of a transmembrane domain of MP19. The expression of Lim2, which was detected in the mouse lens as early as embryonic day 15 (E15

Naturally Occurring Frameshift Mutations in the tvb Receptor Gene Are Responsible for Decreased Susceptibility of Chicken to Infection with Avian Leukosis Virus Subgroups B, D, and E.

Science.gov (United States)

Li, Xinjian; Chen, Weiguo; Zhang, Huanmin; Li, Aijun; Shu, Dingming; Li, Hongxing; Dai, Zhenkai; Yan, Yiming; Zhang, Xinheng; Lin, Wencheng; Ma, Jingyun; Xie, Qingmei

2018-04-15

The group of highly related avian leukosis viruses (ALVs) in chickens are thought to have evolved from a common retroviral ancestor into six subgroups, A to E and J. These ALV subgroups use diverse cellular proteins encoded by four genetic loci in chickens as receptors to gain entry into host cells. Hosts exposed to ALVs might be under selective pressure to develop resistance to ALV infection. Indeed, resistance alleles have previously been identified in all four receptor loci in chickens. The tvb gene encodes a receptor, which determines the susceptibility of host cells to ALV subgroup B (ALV-B), ALV-D, and ALV-E. Here we describe the identification of two novel alleles of the tvb receptor gene, which possess independent insertions each within exon 4. The insertions resulted in frameshift mutations that reveal a premature stop codon that causes nonsense-mediated decay of the mutant mRNA and the production of truncated Tvb protein. As a result, we observed that the frameshift mutations in the tvb gene significantly lower the binding affinity of the truncated Tvb receptors for the ALV-B, ALV-D, and ALV-E envelope glycoproteins and significantly reduce susceptibility to infection by ALV-B, ALV-D and ALV-E in vitro and in vivo Taken together, these findings suggest that frameshift mutation can be a molecular mechanism of reducing susceptibility to ALV and enhance our understanding of virus-host coevolution. IMPORTANCE Avian leukosis virus (ALV) once caused devastating economic loss to the U.S. poultry industry prior the current eradication schemes in place, and it continues to cause severe calamity to the poultry industry in China and Southeast Asia, where deployment of a complete eradication scheme remains a challenge. The tvb gene encodes the cellular receptor necessary for subgroup B, D, and E ALV infection. Two tvb allelic variants that resulted from frameshift mutations have been identified in this study, which have been shown to have significantly reduced

Selection of target mutation in rat gastrointestinal tract E. coli by minute dosage of enrofloxacin.

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Lin, Dachuan; Chen, Kaichao; Li, Ruichao; Liu, Lizhang; Guo, Jiubiao; Yao, Wen; Chen, Sheng

2014-01-01

It has been suggested that bacterial resistance is selected within a mutation selection window of antibiotics. More recent studies showed that even extremely low concentration of antibiotic could select resistant bacteria in vitro. Yet little is known about the exact antibiotic concentration range that can effectively select for resistant organisms in animal gastrointestinal (GI) tract. In this study, the effect of different dosages of enrofloxacin on resistance and mutation development in rat GI tract E. coli was investigated by determining the number of resistant E. coli recoverable from rat fecal samples. Our data showed that high dose antibiotic treatment could effectively eliminate E. coli with single gyrA mutation in the early course of treatment, yet the eradication effects diminished upon prolonged treatment. Therapeutic and sub-therapeutic dose (1/10 and 1/100 of therapeutic doses) of enrofloxacin could effectively select for mutation in GI tract E. coli at the later course of enrofloxacin treatment and during the cessation periods. Surprisingly, very low dose of enrofloxacin (1/1000 therapeutic dose) could also select for mutation in GI tract E. coli at the later course of enrofloxacin treatment, only with slightly lower efficiency. No enrofloxacin-resistant E. coli could be selected at all test levels of enrofloxacin during long term treatment and the strength of antibiotic treatment does not alter the overall level of E. coli in rat GI tract. This study demonstrated that long term antibiotic treatment seems to be the major trigger for the development of target mutations in GI tract E. coli, which provided insight into the rational use of antibiotics in animal husbandry.

The Role of Conserved N-Linked Glycans on Ebola Virus Glycoprotein 2.

Science.gov (United States)

Lennemann, Nicholas J; Walkner, Madeline; Berkebile, Abigail R; Patel, Neil; Maury, Wendy

2015-10-01

N-linked glycosylation is a common posttranslational modification found on viral glycoproteins (GPs) and involved in promoting expression, cellular attachment, protection from proteases, and antibody evasion. The GP subunit GP2 of filoviruses contains 2 completely conserved N-linked glycosylation sites (NGSs) at N563 and N618, suggesting that they have been maintained through selective pressures. We assessed mutants lacking these glycans for expression and function to understand the role of these sites during Ebola virus entry. Elimination of either GP2 glycan individually had a modest effect on GP expression and no impact on antibody neutralization of vesicular stomatitis virus pseudotyped with Ebola virus GP. However, loss of the N563 glycan enhanced entry by 2-fold and eliminated GP detection by a well-characterized monoclonal antibody KZ52. Loss of both sites dramatically decreased GP expression and abolished entry. Surprisingly, a GP that retained a single NGS at N563, eliminating the remaining 16 NGSs from GP1 and GP2, had detectable expression, a modest increase in entry, and pronounced sensitivity to antibody neutralization. Our findings support the importance of the GP2 glycans in GP expression/structure, transduction efficiency, and antibody neutralization, particularly when N-linked glycans are also removed from GP1. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The effect of charge-introduction mutations on E. coli thioredoxin stability.

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Perez-Jimenez, Raul; Godoy-Ruiz, Raquel; Ibarra-Molero, Beatriz; Sanchez-Ruiz, Jose M

2005-04-01

Technological applications of proteins are often hampered by their low-stability and, consequently, the development of procedures for protein stabilization is of considerable biotechnological interest. Here, we use simple electrostatics to determine positions in E. coli thioredoxin at which mutations that introduce new charged residues are expected to lead to stability enhancement. We also obtain the corresponding mutants and characterize their stability using differential scanning calorimetry. The results are interpreted in terms of the accessibility in the native structure of the mutated residues and the potential effect of the mutations on the residual structure of the denatured state.

Analysis of the B-RAFV600E mutation in cutaneous melanoma patients with occupational sun exposure

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CANDIDO, SAVERIO; RAPISARDA, VENERANDO; MARCONI, ANDREA; MALAPONTE, GRAZIA; BEVELACQUA, VALENTINA; GANGEMI, PIETRO; SCALISI, AURORA; McCUBREY, JAMES A.; MAESTRO, ROBERTA; SPANDIDOS, DEMETRIOS A.; FENGA, CONCETTINA; LIBRA, MASSIMO

2014-01-01

Sun-exposure is one of the risk factors associated with the development of a cutaneous neoplasm. In melanoma, the Ras-Raf-MEK-ERK (MAPK) signaling pathway is constitutively activated through multiple mechanisms, including B-RAF mutation. It has been hypothesized that B-RAF mutations in melanocytic lesions arise from DNA damage induced by ultraviolet (UV) radiation. However, it is still discussed if B-RAF mutations are associated with melanoma patients exposed to the sun. Therefore, in the present study, the known B-RAFV600E mutation was analysed in melanoma samples from 30 indoor and 38 outdoor workers. B-RAFV600E mutation was detected in 52 and 73% of outdoor workers and indoor workers, respectively. Of note, this mutation was identified in 12 of 14 (85%) melanoma of the trunk diagnosed in indoor workers and in 9 of 19 (47%) samples from outdoor workers (p=0.03). By analyzing melanomas of other body sites, no statistical difference in the frequency of B-RAFV600E mutation was identified between the groups of workers. It appears that the mutation detected among indoor workers may be associated with a recreational or intermittent exposure to the sun, as usually the trunk is a sun-protected body site. Overall, these data indicate that the B-RAFV600E mutation detected in melanoma is not associated with a chronic exposure to the sun. Mutations detected in other genes may also contribute to melanoma development in the subset of patients exposed to UV radiation. PMID:24424406

Novel USH2A mutations in Japanese Usher syndrome type 2 patients: marked differences in the mutation spectrum between the Japanese and other populations.

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Nakanishi, Hiroshi; Ohtsubo, Masafumi; Iwasaki, Satoshi; Hotta, Yoshihiro; Usami, Shin-Ichi; Mizuta, Kunihiro; Mineta, Hiroyuki; Minoshima, Shinsei

2011-07-01

Usher syndrome (USH) is an autosomal recessive disorder characterized by retinitis pigmentosa and hearing loss. USH type 2 (USH2) is the most common type of USH and is frequently caused by mutations in USH2A. In a recent mutation screening of USH2A in Japanese USH2 patients, we identified 11 novel mutations in 10 patients and found the possible frequent mutation c.8559-2A>G in 4 of 10 patients. To obtain a more precise mutation spectrum, we analyzed further nine Japanese patients in this study. We identified nine mutations, of which eight were novel. This result indicates that the mutation spectrum for USH2A among Japanese patients largely differs from Caucasian, Jewish and Palestinian patients. Meanwhile, we did not find the c.8559-2A>G in this study. Haplotype analysis of the c.8559-2G (mutated) alleles using 23 single nucleotide polymorphisms surrounding the mutation revealed an identical haplotype pattern of at least 635 kb in length, strongly suggesting that the mutation originated from a common ancestor. The fact that all patients carrying c.8559-2A>G came from western Japan suggests that the mutation is mainly distributed in that area; indeed, most of the patients involved in this study came from eastern Japan, which contributed to the absence of c.8559-2A>G.

PHKA2 mutation spectrum in Korean patients with glycogen storage disease type IX: prevalence of deletion mutations.

Science.gov (United States)

Choi, Rihwa; Park, Hyung-Doo; Kang, Ben; Choi, So Yoon; Ki, Chang-Seok; Lee, Soo-Youn; Kim, Jong-Won; Song, Junghan; Choe, Yon Ho

2016-04-21

Molecular diagnosis of glycogen storage diseases (GSDs) is important to enable accurate diagnoses and make appropriate therapeutic plans. The aim of this study was to evaluate the PHKA2 mutation spectrum in Korean patients with GSD type IX. Thirteen Korean patients were tested for PHKA2 mutations using direct sequencing and a multiplex polymerase chain reaction method. A comprehensive review of the literature on previously reported PHKA2 mutations in other ethnic populations was conducted for comparison. Among 13 patients tested, six unrelated male patients with GSD IX aged 2 to 6 years at the first diagnostic work-up for hepatomegaly with elevated aspartate transaminase (AST) and alanine transaminase (ALT) were found to have PHKA2 mutations. These patients had different PHKA2 mutations: five were known mutations (c.537 + 5G > A, c.884G > A [p.Arg295His], c.3210_3212delGAG [p.Arg1072del], exon 8 deletion, and exons 27-33 deletion) and one was a novel mutation (exons 18-33 deletion). Notably, the most common type of mutation was gross deletion, in contrast to other ethnic populations in which the most common mutation type was sequence variant. This study expands our knowledge of the PHKA2 mutation spectrum of GSD IX. Considering the PHKA2 mutation spectrum in Korean patients with GSD IX, molecular diagnostic methods for deletions should be conducted in conjunction with direct sequence analysis to enable accurate molecular diagnosis of this disease in the Korean population.

Utility of BRAF V600E mutation detection in cytologically indeterminate thyroid nodules

Directory of Open Access Journals (Sweden)

Rowe Leslie R

2006-04-01

Full Text Available Abstract Background Fine needle aspiration (FNA is widely utilized for evaluation of patients with thyroid nodules. However, approximately 30% are indeterminate for malignancy. Recently, a mutation in the BRAF gene has been reported to be the most common genetic event in papillary thyroid carcinoma (PTC. In this retrospective study, we assessed the utility of BRAF V600E mutation detection for refining indeterminate preoperative cytologic diagnoses in patients with PTC. Methods Archival indeterminate thyroid FNAs and corresponding formalin-fixed, paraffin-embedded (FFPE surgical samples with PTC were identified in our patient files. DNA extracted from slide scape lysates and 5 μm FFPE sections were evaluated for the BRAF V600E mutation using LightCycler PCR and fluorescent melting curve analysis (LCPCR. Amplification products that showed deviation from the wild-type genomic DNA melting peak, discordant FNA and FFPE matched pairs, and all benign control samples, underwent direct DNA sequencing. Results A total of 19 indeterminate thyroid FNAs demonstrating PTC on FFPE surgical samples were included in the study. Using BRAF mutation analysis, the preoperative diagnosis of PTC was confirmed in 3/19 (15.8% FNA samples that could not be conclusively diagnosed on cytology alone. However, 9/19 (47.4% FFPE tissue samples were positive for the V600E mutation. Of the discordant pairs, 5/6 FNAs contained less than 50% tumor cells. Conclusion When used with indeterminate FNA samples, BRAF mutation analysis may be a useful adjunct technique for confirming the diagnosis of malignancy in an otherwise equivocal case. However, overall tumor cell content of some archival FNA smear slides is a limiting factor for mutation detection.

Novel GABRG2 mutations cause familial febrile seizures

Science.gov (United States)

Boillot, Morgane; Morin-Brureau, Mélanie; Picard, Fabienne; Weckhuysen, Sarah; Lambrecq, Virginie; Minetti, Carlo; Striano, Pasquale; Zara, Federico; Iacomino, Michele; Ishida, Saeko; An-Gourfinkel, Isabelle; Daniau, Mailys; Hardies, Katia; Baulac, Michel; Dulac, Olivier; Leguern, Eric; Nabbout, Rima

2015-01-01

Objective: To identify the genetic cause in a large family with febrile seizures (FS) and temporal lobe epilepsy (TLE) and subsequently search for additional mutations in a cohort of 107 families with FS, with or without epilepsy. Methods: The cohort consisted of 1 large family with FS and TLE, 64 smaller French families recruited through a national French campaign, and 43 Italian families. Molecular analyses consisted of whole-exome sequencing and mutational screening. Results: Exome sequencing revealed a p.Glu402fs*3 mutation in the γ2 subunit of the GABAA receptor gene (GABRG2) in the large family with FS and TLE. Three additional nonsense and frameshift GABRG2 mutations (p.Arg136*, p.Val462fs*33, and p.Pro59fs*12), 1 missense mutation (p.Met199Val), and 1 exonic deletion were subsequently identified in 5 families of the follow-up cohort. Conclusions: We report GABRG2 mutations in 5.6% (6/108) of families with FS, with or without associated epilepsy. This study provides evidence that GABRG2 mutations are linked to the FS phenotype, rather than epilepsy, and that loss-of-function of GABAA receptor γ2 subunit is the probable underlying pathogenic mechanism. PMID:27066572

Glycoprotein 130 receptor signaling mediates α-cell dysfunction in a rodent model of type 2 diabetes

DEFF Research Database (Denmark)

Chow, Samuel Z; Speck, Madeleine; Yoganathan, Piriya

2014-01-01

Dysregulated glucagon secretion accompanies islet inflammation in type 2 diabetes. We recently discovered that interleukin (IL)-6 stimulates glucagon secretion from human and rodent islets. IL-6 family cytokines require the glycoprotein 130 (gp130) receptor to signal. In this study, we elucidated...

Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

International Nuclear Information System (INIS)

Leberer, E.; Charuk, J.H.M.; MacLennan, D.H.; Green, N.M.

1989-01-01

Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1,308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH 2 -terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca 2+ . The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45 C 2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca 2+ with the membrane. The authors propose that this lumenal Ca 2+ binding glycoprotein of the sarcoplasmic reticulum be designated sarcalumenin

Mutations in SLC33A1 cause a lethal autosomal-recessive disorder with congenital cataracts, hearing loss, and low serum copper and ceruloplasmin

DEFF Research Database (Denmark)

Huppke, Peter; Brendel, Cornelia; Kalscheuer, Vera

2012-01-01

or compound heterozygous mutations for all affected subjects in SLC33A1 encoding a highly conserved acetylCoA transporter (AT-1) required for acetylation of multiple gangliosides and glycoproteins. The mutations were found to cause reduced or absent AT-1 expression and abnormal intracellular localization...

JAK and MPL mutations in myeloid malignancies.

Science.gov (United States)

Tefferi, Ayalew

2008-03-01

The Janus family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3 and tyrosine kinase 2) transduces signals downstream of type I and II cytokine receptors via signal transducers and activators of transcription (STATs). JAK3 is important in lymphoid and JAK2 in myeloid cell proliferation and differentiation. The thrombopoietin receptor MPL is one of several JAK2 cognate receptors and is essential for myelopoiesis in general and megakaryopoiesis in particular. Germline loss-of-function (LOF) JAK3 and MPL mutations cause severe combined immunodeficiency and congenital amegakaryocytic thrombocytopenia, respectively. Germline gain-of-function (GOF) MPL mutation (MPLS505N) causes familial thrombocytosis. Somatic JAK3 (e.g. JAK3A572V, JAK3V722I, JAK3P132T) and fusion JAK2 (e.g. ETV6-JAK2, PCM1-JAK2, BCR-JAK2) mutations have respectively been described in acute megakaryocytic leukemia and acute leukemia/chronic myeloid malignancies. However, current attention is focused on JAK2 (e.g. JAK2V617F, JAK2 exon 12 mutations) and MPL (e.g. MPLW515L/K/S, MPLS505N) mutations associated with myeloproliferative neoplasms (MPNs). A JAK2 mutation, primarily JAK2V617F, is invariably associated with polycythemia vera (PV). The latter mutation also occurs in the majority of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). MPL mutational frequency in MPNs is substantially less (<10%). In general, despite a certain degree of genotype - phenotype correlations, the prognostic relevance of harbouring one of these mutations, or their allele burden when present, remains dubious. Regardless, based on the logical assumption that amplified JAK-STAT signalling is central to the pathogenesis of PV, ET and PMF, several anti-JAK2 tyrosine kinase inhibitors have been developed and are currently being tested in humans with these disorders.

Extensive overproduction of the AdhE protein by rng mutations depends on mutations in the cra gene or in the Cra-box of the adhE promoter.

Science.gov (United States)

Kaga, Naoko; Umitsuki, Genryou; Clark, David P; Nagai, Kazuo; Wachi, Masaaki

2002-07-05

Escherichia coli RNase G encoded by the rng gene is involved in degradation of adhE mRNA. Overproduction of the AdhE protein by rng mutants was found to depend on the genetic background of strains derived from DC272 (adhC81) or MC1061. We found that DC272 carried a point mutation in the Cra-binding site of the adhE promoter. The Cra protein encoded by the cra gene is known to act as a repressor of adhE. P1-phage-mediated transduction and lacZ fusion analysis with the mutant adhE promoter confirmed that this mutation is responsible for overproduction. On the other hand, Southern hybridization revealed that MC1061 had a 0.85-kb deletion of the cra gene. Overproduction of AdhE in the MC1061 background was reversed to the wild-type levels by introduction of a plasmid carrying the cra(+) gene. These results indicated that expression of the adhE gene was regulated transcriptionally by Cra and posttranscriptionally by RNase G. (c) 2002 Elsevier Science (USA).

MLL2 mutation detection in 86 patients with Kabuki syndrome: a genotype-phenotype study.

Science.gov (United States)

Makrythanasis, P; van Bon, B W; Steehouwer, M; Rodríguez-Santiago, B; Simpson, M; Dias, P; Anderlid, B M; Arts, P; Bhat, M; Augello, B; Biamino, E; Bongers, E M H F; Del Campo, M; Cordeiro, I; Cueto-González, A M; Cuscó, I; Deshpande, C; Frysira, E; Izatt, L; Flores, R; Galán, E; Gener, B; Gilissen, C; Granneman, S M; Hoyer, J; Yntema, H G; Kets, C M; Koolen, D A; Marcelis, C l; Medeira, A; Micale, L; Mohammed, S; de Munnik, S A; Nordgren, A; Psoni, S; Reardon, W; Revencu, N; Roscioli, T; Ruiterkamp-Versteeg, M; Santos, H G; Schoumans, J; Schuurs-Hoeijmakers, J H M; Silengo, M C; Toledo, L; Vendrell, T; van der Burgt, I; van Lier, B; Zweier, C; Reymond, A; Trembath, R C; Perez-Jurado, L; Dupont, J; de Vries, B B A; Brunner, H G; Veltman, J A; Merla, G; Antonarakis, S E; Hoischen, A

2013-12-01

Recently, pathogenic variants in the MLL2 gene were identified as the most common cause of Kabuki (Niikawa-Kuroki) syndrome (MIM#147920). To further elucidate the genotype-phenotype correlation, we studied a large cohort of 86 clinically defined patients with Kabuki syndrome (KS) for mutations in MLL2. All patients were assessed using a standardized phenotype list and all were scored using a newly developed clinical score list for KS (MLL2-Kabuki score 0-10). Sequencing of the full coding region and intron-exon boundaries of MLL2 identified a total of 45 likely pathogenic mutations (52%): 31 nonsense, 10 missense and four splice-site mutations, 34 of which were novel. In five additional patients, novel, i.e. non-dbSNP132 variants of clinically unknown relevance, were identified. Patients with likely pathogenic nonsense or missense MLL2 mutations were usually more severely affected (median 'MLL2-Kabuki score' of 6) as compared to the patients without MLL2 mutations (median 'MLL2-Kabuki score' of 5), a significant difference (p < 0.0014). Several typical facial features such as large dysplastic ears, arched eyebrows with sparse lateral third, blue sclerae, a flat nasal tip with a broad nasal root, and a thin upper and a full lower lip were observed more often in mutation positive patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

PMS2 monoallelic mutation carriers: the known unknown.

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Goodenberger, McKinsey L; Thomas, Brittany C; Riegert-Johnson, Douglas; Boland, C Richard; Plon, Sharon E; Clendenning, Mark; Win, Aung Ko; Senter, Leigha; Lipkin, Steven M; Stadler, Zsofia K; Macrae, Finlay A; Lynch, Henry T; Weitzel, Jeffrey N; de la Chapelle, Albert; Syngal, Sapna; Lynch, Patrick; Parry, Susan; Jenkins, Mark A; Gallinger, Steven; Holter, Spring; Aronson, Melyssa; Newcomb, Polly A; Burnett, Terrilea; Le Marchand, Loïc; Pichurin, Pavel; Hampel, Heather; Terdiman, Jonathan P; Lu, Karen H; Thibodeau, Stephen; Lindor, Noralane M

2016-01-01

Germ-line mutations in MLH1, MSH2, MSH6, and PMS2 have been shown to cause Lynch syndrome. The penetrance of the cancer and tumor spectrum has been repeatedly studied, and multiple professional societies have proposed clinical management guidelines for affected individuals. Several studies have demonstrated a reduced penetrance for monoallelic carriers of PMS2 mutations compared with the other mismatch repair (MMR) genes, but clinical management guidelines have largely proposed the same screening recommendations for all MMR gene carriers. The authors considered whether enough evidence existed to propose new screening guidelines specific to PMS2 mutation carriers with regard to age at onset and frequency of colonic screening. Published reports of PMS2 germ-line mutations were combined with unpublished cases from the authors' research registries and clinical practices, and a discussion of potential modification of cancer screening guidelines was pursued. A total of 234 monoallelic PMS2 mutation carriers from 170 families were included. Approximately 8% of those with colorectal cancer (CRC) were diagnosed before age 30, and each of these tumors presented on the left side of the colon. As it is currently unknown what causes the early onset of CRC in some families with monoallelic PMS2 germline mutations, the authors recommend against reducing cancer surveillance guidelines in families found having monoallelic PMS2 mutations in spite of the reduced penetrance.Genet Med 18 1, 13-19.

Conditional expression of the vesicular stomatitis virus glycoprotein gene in Escherichia coli.

OpenAIRE

Rose, J K; Shafferman, A

1981-01-01

Bacterial plasmids that directed expression of the vesicular stomatitis virus glycoprotein (G-protein) gene under control of the tryptophan operon regulatory region were constructed. A plasmid directing the synthesis of a G-protein-like protein (containing the NH2-terminal segment of seven amino acids encoded by the trpE gene fused to the complete G-protein sequence lacking only its NH2-terminal methionine) could be transformed into trpR+ (repressed) but not into trpR- (derepressed) cells. Th...

The prevalence of ABCB1:c.227_230delATAG mutation in affected dog breeds from European countries.

Science.gov (United States)

Firdova, Zuzana; Turnova, Evelina; Bielikova, Marcela; Turna, Jan; Dudas, Andrej

2016-06-01

Deletion of 4-base pairs in the canine ABCB1 (MDR1) gene, responsible for encoding P-glycoprotein, leads to nonsense frame-shift mutation, which causes hypersensitivity to macrocyclic lactones drugs (e.g. ivermectin). To date, at least 12 purebred dog breeds have been found to be affected by this mutation. The aim of this study was to update information about the prevalence of ABCB1 mutation (c.227_230delATAG) in predisposed breeds in multiple European countries. This large scale survey also includes countries which were not involved in previous studies. The samples were collected in the period from 2012 to 2014. The overview is based on genotyping data of 4729 individuals. The observed mutant allele frequencies were 58.5% (Smooth Collie), 48.3% (Rough Collie), 35% (Australian Shepherd), 30.3% (Shetland Sheepdog), 28.1% (Silken Windhound), 26.1% (Miniature Australian Shepherd), 24.3% (Longhaired Whippet), 16.2% (White Swiss Shepherd) and 0% (Border Collie). The possible presence of an ABCB1 mutant allele in Akita-Inu breed has been investigated with negative results. This information could be helpful for breeders in optimization of their breeding strategy and for veterinarians when prescribing drug therapy for dogs of predisposed breeds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acid-induced movements in the glycoprotein shell of an alphavirus turn the spikes into membrane fusion mode

OpenAIRE

Haag, Lars; Garoff, Henrik; Xing, Li; Hammar, Lena; Kan, Sin-Tau; Cheng, R.Holland

2002-01-01

In the icosahedral (T = 4) Semliki Forest virus, the envelope protomers, i.e. E1–E2 heterodimers, make one-to-one interactions with capsid proteins below the viral lipid bilayer, transverse the membrane and form an external glycoprotein shell with projections. The shell is organized by protomer domains interacting as hexamers and pentamers around shell openings at icosahedral 2- and 5-fold axes, respectively, and the projections by other domains associating as trimers at 3- and quasi 3-fold a...

Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

DEFF Research Database (Denmark)

Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind

2015-01-01

transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1....../Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes...

Analysis of the BRAFV600E mutation in 19 cases of Langerhans cell histiocytosis in Japan.

Science.gov (United States)

Sasaki, Yuya; Guo, Ying; Arakawa, Fumiko; Miyoshi, Hiroaki; Yoshida, Noriaki; Koga, Yuhki; Nakashima, Kazutaka; Kurita, Daisuke; Niino, Daisuke; Seto, Masao; Ohshima, Koichi

2017-09-01

Langerhans cell histiocytosis (LCH) is a rare disease characterized by clonal proliferation of CD1a- and CD207 (langerin)-positive dendritic cells. Mutated BRAF (p.V600E) is observed in histiocyte-related diseases and dendritic cell-related diseases, including LCH. BRAFV600E is observed in some LCH cases and is thought to be involved in maintaining MAPK activation. We retrospectively analyzed BRAFV600E in 19 patients diagnosed with LCH. In our study, direct sequencing for exon 15, a mutation hotspot, demonstrated that 4 out of the 19 patients (21%) harbored a GTG > GAG (valine > glutamic acid) base substitution, which encodes BRAFV600E. The clinical impact of BRAFV600E in such diseases is unclear. The frequency of BRAFV600E in our LCH patients from Japan was lower than that reported in the United States and in Germany. However, reports from Asia tend to show a lower rate of the BRAFV600E mutation. These results imply the possibility of different genetic backgrounds in the pathogenesis of LCH across various ethnicities. We also performed an immunohistochemical analysis to detect BRAFV600E using the mutation-specific monoclonal antibody. However, immunohistochemical analysis failed to detect any mutated protein in any of the 4 BRAFV600E-positive cases. This implies that at present, BRAFV600E should be assessed by direct sequencing. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Mutational spectrum in a worldwide study of 29,700 families with BRCA1 or BRCA2 mutations.

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Rebbeck, Timothy R; Friebel, Tara M; Friedman, Eitan; Hamann, Ute; Huo, Dezheng; Kwong, Ava; Olah, Edith; Olopade, Olufunmilayo I; Solano, Angela R; Teo, Soo-Hwang; Thomassen, Mads; Weitzel, Jeffrey N; Chan, T L; Couch, Fergus J; Goldgar, David E; Kruse, Torben A; Palmero, Edenir Inêz; Park, Sue Kyung; Torres, Diana; van Rensburg, Elizabeth J; McGuffog, Lesley; Parsons, Michael T; Leslie, Goska; Aalfs, Cora M; Abugattas, Julio; Adlard, Julian; Agata, Simona; Aittomäki, Kristiina; Andrews, Lesley; Andrulis, Irene L; Arason, Adalgeir; Arnold, Norbert; Arun, Banu K; Asseryanis, Ella; Auerbach, Leo; Azzollini, Jacopo; Balmaña, Judith; Barile, Monica; Barkardottir, Rosa B; Barrowdale, Daniel; Benitez, Javier; Berger, Andreas; Berger, Raanan; Blanco, Amie M; Blazer, Kathleen R; Blok, Marinus J; Bonadona, Valérie; Bonanni, Bernardo; Bradbury, Angela R; Brewer, Carole; Buecher, Bruno; Buys, Saundra S; Caldes, Trinidad; Caliebe, Almuth; Caligo, Maria A; Campbell, Ian; Caputo, Sandrine M; Chiquette, Jocelyne; Chung, Wendy K; Claes, Kathleen B M; Collée, J Margriet; Cook, Jackie; Davidson, Rosemarie; de la Hoya, Miguel; De Leeneer, Kim; de Pauw, Antoine; Delnatte, Capucine; Diez, Orland; Ding, Yuan Chun; Ditsch, Nina; Domchek, Susan M; Dorfling, Cecilia M; Velazquez, Carolina; Dworniczak, Bernd; Eason, Jacqueline; Easton, Douglas F; Eeles, Ros; Ehrencrona, Hans; Ejlertsen, Bent; Engel, Christoph; Engert, Stefanie; Evans, D Gareth; Faivre, Laurence; Feliubadaló, Lidia; Ferrer, Sandra Fert; Foretova, Lenka; Fowler, Jeffrey; Frost, Debra; Galvão, Henrique C R; Ganz, Patricia A; Garber, Judy; Gauthier-Villars, Marion; Gehrig, Andrea; Gerdes, Anne-Marie; Gesta, Paul; Giannini, Giuseppe; Giraud, Sophie; Glendon, Gord; Godwin, Andrew K; Greene, Mark H; Gronwald, Jacek; Gutierrez-Barrera, Angelica; Hahnen, Eric; Hauke, Jan; Henderson, Alex; Hentschel, Julia; Hogervorst, Frans B L; Honisch, Ellen; Imyanitov, Evgeny N; Isaacs, Claudine; Izatt, Louise; Izquierdo, Angel; Jakubowska, Anna; James, Paul; Janavicius, Ramunas; Jensen, Uffe Birk; John, Esther M; Vijai, Joseph; Kaczmarek, Katarzyna; Karlan, Beth Y; Kast, Karin; Investigators, KConFab; Kim, Sung-Won; Konstantopoulou, Irene; Korach, Jacob; Laitman, Yael; Lasa, Adriana; Lasset, Christine; Lázaro, Conxi; Lee, Annette; Lee, Min Hyuk; Lester, Jenny; Lesueur, Fabienne; Liljegren, Annelie; Lindor, Noralane M; Longy, Michel; Loud, Jennifer T; Lu, Karen H; Lubinski, Jan; Machackova, Eva; Manoukian, Siranoush; Mari, Véronique; Martínez-Bouzas, Cristina; Matrai, Zoltan; Mebirouk, Noura; Meijers-Heijboer, Hanne E J; Meindl, Alfons; Mensenkamp, Arjen R; Mickys, Ugnius; Miller, Austin; Montagna, Marco; Moysich, Kirsten B; Mulligan, Anna Marie; Musinsky, Jacob; Neuhausen, Susan L; Nevanlinna, Heli; Ngeow, Joanne; Nguyen, Huu Phuc; Niederacher, Dieter; Nielsen, Henriette Roed; Nielsen, Finn Cilius; Nussbaum, Robert L; Offit, Kenneth; Öfverholm, Anna; Ong, Kai-Ren; Osorio, Ana; Papi, Laura; Papp, Janos; Pasini, Barbara; Pedersen, Inge Sokilde; Peixoto, Ana; Peruga, Nina; Peterlongo, Paolo; Pohl, Esther; Pradhan, Nisha; Prajzendanc, Karolina; Prieur, Fabienne; Pujol, Pascal; Radice, Paolo; Ramus, Susan J; Rantala, Johanna; Rashid, Muhammad Usman; Rhiem, Kerstin; Robson, Mark; Rodriguez, Gustavo C; Rogers, Mark T; Rudaitis, Vilius; Schmidt, Ane Y; Schmutzler, Rita Katharina; Senter, Leigha; Shah, Payal D; Sharma, Priyanka; Side, Lucy E; Simard, Jacques; Singer, Christian F; Skytte, Anne-Bine; Slavin, Thomas P; Snape, Katie; Sobol, Hagay; Southey, Melissa; Steele, Linda; Steinemann, Doris; Sukiennicki, Grzegorz; Sutter, Christian; Szabo, Csilla I; Tan, Yen Y; Teixeira, Manuel R; Terry, Mary Beth; Teulé, Alex; Thomas, Abigail; Thull, Darcy L; Tischkowitz, Marc; Tognazzo, Silvia; Toland, Amanda Ewart; Topka, Sabine; Trainer, Alison H; Tung, Nadine; van Asperen, Christi J; van der Hout, Annemieke H; van der Kolk, Lizet E; van der Luijt, Rob B; Van Heetvelde, Mattias; Varesco, Liliana; Varon-Mateeva, Raymonda; Vega, Ana; Villarreal-Garza, Cynthia; von Wachenfeldt, Anna; Walker, Lisa; Wang-Gohrke, Shan; Wappenschmidt, Barbara; Weber, Bernhard H F; Yannoukakos, Drakoulis; Yoon, Sook-Yee; Zanzottera, Cristina; Zidan, Jamal; Zorn, Kristin K; Hutten Selkirk, Christina G; Hulick, Peter J; Chenevix-Trench, Georgia; Spurdle, Amanda B; Antoniou, Antonis C; Nathanson, Katherine L

2018-05-01

The prevalence and spectrum of germline mutations in BRCA1 and BRCA2 have been reported in single populations, with the majority of reports focused on White in Europe and North America. The Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) has assembled data on 18,435 families with BRCA1 mutations and 11,351 families with BRCA2 mutations ascertained from 69 centers in 49 countries on six continents. This study comprehensively describes the characteristics of the 1,650 unique BRCA1 and 1,731 unique BRCA2 deleterious (disease-associated) mutations identified in the CIMBA database. We observed substantial variation in mutation type and frequency by geographical region and race/ethnicity. In addition to known founder mutations, mutations of relatively high frequency were identified in specific racial/ethnic or geographic groups that may reflect founder mutations and which could be used in targeted (panel) first pass genotyping for specific populations. Knowledge of the population-specific mutational spectrum in BRCA1 and BRCA2 could inform efficient strategies for genetic testing and may justify a more broad-based oncogenetic testing in some populations. © 2018 Wiley Periodicals, Inc.

Novel SCARB2 mutation in action myoclonus-renal failure syndrome and evaluation of SCARB2 mutations in isolated AMRF features

Directory of Open Access Journals (Sweden)

Hopfner Franziska

2011-10-01

Full Text Available Abstract Background Action myoclonus-renal failure syndrome is a hereditary form of progressive myoclonus epilepsy associated with renal failure. It is considered to be an autosomal-recessive disease related to loss-of-function mutations in SCARB2. We studied a German AMRF family, additionally showing signs of demyelinating polyneuropathy and dilated cardiomyopathy. To test the hypothesis whether isolated appearance of individual AMRF syndrome features could be related to heterozygote SCARB2 mutations, we screened for SCARB2 mutations in unrelated patients showing isolated AMRF features. Methods In the AMRF family all exons of SCARB2 were analyzed by Sanger sequencing. The mutation screening of unrelated patients with isolated AMRF features affected by either epilepsy (n = 103, progressive myoclonus epilepsy or generalized epilepsy, demyelinating polyneuropathy (n = 103, renal failure (n = 192 or dilated cardiomyopathy (n = 85 was performed as high resolution melting curve analysis of the SCARB2 exons. Results A novel homozygous 1 bp deletion (c.111delC in SCARB2 was found by sequencing three affected homozygous siblings of the affected family. A heterozygous sister showed generalized seizures and reduction of nerve conduction velocity in her legs. No mutations were found in the epilepsy, renal failure or dilated cardiomyopathy samples. In the polyneuropathy sample two individuals with demyelinating disease were found to be carriers of a SCARB2 frameshift mutation (c.666delCCTTA. Conclusions Our findings indicate that demyelinating polyneuropathy and dilated cardiomyopathy are part of the action myoclonus-renal failure syndrome. Moreover, they raise the possibility that in rare cases heterozygous SCARB2 mutations may be associated with PNP features.

Prediction of conserved sites and domains in glycoproteins B, C and D of herpes viruses.

Science.gov (United States)

Rasheed, Muhammad Asif; Ansari, Abdur Rahman; Ihsan, Awais; Navid, Muhammad Tariq; Ur-Rehman, Shahid; Raza, Sohail

2018-03-01

Glycoprotein B (gB), C (gC) and D (gD) of herpes simplex virus are implicated in virus adsorption and penetration. The gB, gC and gD are glycoproteins for different processes of virus binding and attachment to the host cells. Moreover, their expression is necessary and sufficient to induce cell fusion in the absence of other glycoproteins. Egress of herpes simplex virus (HSV) and other herpes viruses from cells involves extensive modification of cellular membranes and sequential envelopment, de-envelopment and re-envelopment steps. Viral glycoproteins are important in these processes, and frequently two or more glycoproteins can largely suffice in any step. Hence, we target the 3 important glycoproteins (B, C and D) of eight different herpes viruses of different species. These species include human (HSV1 and 2), bovine (BHV1), equine (EHV1 and 4), chicken (ILT1 and MDV2) and pig (PRV1). By applying different bioinformatics tools, we highlighted the conserved sites in these glycoproteins which might be most significant regarding attachment and infection of the viruses. Moreover the conserved domains in these glycoproteins are also highlighted. From this study, we will able to analyze the role of different viral glycoproteins of different species during herpes virus adsorption and penetration. Moreover, this study will help to construct the antivirals that target the glycoproteins of different herpes viruses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ammonia transport in the kidney by Rhesus glycoproteins

Science.gov (United States)

Verlander, Jill W.

2014-01-01

Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4+ with a new model in which specific and regulated transport of both NH3 and NH4+ across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport. PMID:24647713

Structure of the membrane anchor of pestivirus glycoprotein E(rns, a long tilted amphipathic helix.

Directory of Open Access Journals (Sweden)

Daniel Aberle

2014-02-01

Full Text Available E(rns is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns membrane contact, processing and secretion.

Structure of the membrane anchor of pestivirus glycoprotein E(rns), a long tilted amphipathic helix.

Science.gov (United States)

Aberle, Daniel; Muhle-Goll, Claudia; Bürck, Jochen; Wolf, Moritz; Reißer, Sabine; Luy, Burkhard; Wenzel, Wolfgang; Ulrich, Anne S; Meyers, Gregor

2014-02-01

E(rns) is an essential virion glycoprotein with RNase activity that suppresses host cellular innate immune responses upon being partially secreted from the infected cells. Its unusual C-terminus plays multiple roles, as the amphiphilic helix acts as a membrane anchor, as a signal peptidase cleavage site, and as a retention/secretion signal. We analyzed the structure and membrane binding properties of this sequence to gain a better understanding of the underlying mechanisms. CD spectroscopy in different setups, as well as Monte Carlo and molecular dynamics simulations confirmed the helical folding and showed that the helix is accommodated in the amphiphilic region of the lipid bilayer with a slight tilt rather than lying parallel to the surface. This model was confirmed by NMR analyses that also identified a central stretch of 15 residues within the helix that is fully shielded from the aqueous layer, which is C-terminally followed by a putative hairpin structure. These findings explain the strong membrane binding of the protein and provide clues to establishing the E(rns) membrane contact, processing and secretion.

Lynch Syndrome Caused by Germline PMS2 Mutations

DEFF Research Database (Denmark)

Ten Broeke, Sanne W; Brohet, Richard M; Tops, Carli M

2015-01-01

PURPOSE: The clinical consequences of PMS2 germline mutations are poorly understood compared with other Lynch-associated mismatch repair gene (MMR) mutations. The aim of this European cohort study was to define the cancer risk faced by PMS2 mutation carriers. METHODS: Data were collected from 98...... PMS2 families ascertained from family cancer clinics that included a total of 2,548 family members and 377 proven mutation carriers. To adjust for potential ascertainment bias, a modified segregation analysis model was used to calculate colorectal cancer (CRC) and endometrial cancer (EC) risks....... Standardized incidence ratios (SIRs) were calculated to estimate risks for other Lynch syndrome-associated cancers. RESULTS: The cumulative risk (CR) of CRC for male mutation carriers by age 70 years was 19%. The CR among female carriers was 11% for CRC and 12% for EC. The mean age of CRC development was 52...

Gain-of-function mutations in the gene encoding the tyrosine phosphatase SHP2 induce hydrocephalus in a catalytically dependent manner.

Science.gov (United States)

Zheng, Hong; Yu, Wen-Mei; Waclaw, Ronald R; Kontaridis, Maria I; Neel, Benjamin G; Qu, Cheng-Kui

2018-03-20

Catalytically activating mutations in Ptpn11 , which encodes the protein tyrosine phosphatase SHP2, cause 50% of Noonan syndrome (NS) cases, whereas inactivating mutations in Ptpn11 are responsible for nearly all cases of the similar, but distinct, developmental disorder Noonan syndrome with multiple lentigines (NSML; formerly called LEOPARD syndrome). However, both types of disease mutations are gain-of-function mutations because they cause SHP2 to constitutively adopt an open conformation. We found that the catalytic activity of SHP2 was required for the pathogenic effects of gain-of-function, disease-associated mutations on the development of hydrocephalus in the mouse. Targeted pan-neuronal knockin of a Ptpn11 allele encoding the active SHP2 E76K mutant resulted in hydrocephalus due to aberrant development of ependymal cells and their cilia. These pathogenic effects of the E76K mutation were suppressed by the additional mutation C459S, which abolished the catalytic activity of SHP2. Moreover, ependymal cells in NSML mice bearing the inactive SHP2 mutant Y279C were also unaffected. Mechanistically, the SHP2 E76K mutant induced developmental defects in ependymal cells by enhancing dephosphorylation and inhibition of the transcription activator STAT3. Whereas STAT3 activity was reduced in Ptpn11 E76K/+ cells, the activities of the kinases ERK and AKT were enhanced, and neural cell-specific Stat3 knockout mice also manifested developmental defects in ependymal cells and cilia. These genetic and biochemical data demonstrate a catalytic-dependent role of SHP2 gain-of-function disease mutants in the pathogenesis of hydrocephalus. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Structural and functional analysis of glycoprotein butyrylcholinesterase using atomistic molecular dynamics

Science.gov (United States)

Bernardi, Austen; Faller, Roland

Atomistic molecular dynamics (MD) has proven to be a powerful tool for studying the structure and dynamics of biological systems on nanosecond to microsecond time scales and nanometer length scales. In this work we study the effects of modifying the glycan distribution on the structure and function of full length monomeric butyrylcholinesterase (BChE). BChE exists as a monomer, dimer, or tetramer, and is a therapeutic glycoprotein with nine asparagine glycosylation sites per monomer. Each monomer acts as a stoichiometric scavenger for organophosphorus (OP) nerve agents (e.g. sarin, soman). Glycan distributions are highly heterogeneous and have been shown experimentally to affect certain glycoproteins' stability and reactivity. We performed structural analysis of various biologically relevant glycoforms of BChE using classical atomistic MD. Functional analysis was performed through binding energy simulations using umbrella sampling with BChE and OP cofactors. Additionally, we assess the quality of the glycans' conformational sampling. We found that the glycan distribution has a significant effect on the structure and function of BChE on timescales available to atomistic MD. This project is funded by the DTRA Grant HDTRA1-15-1-0054.

The effect of lycopene on cytochrome P450 isoenzymes and P-glycoprotein by using human liver microsomes and Caco-2 cell monolayer model.

Science.gov (United States)

Kong, Lingti; Song, Chunli; Ye, Linhu; Xu, Jian; Guo, Daohua; Shi, Qingping

2018-01-11

Lycopene is widely used as a dietary supplement. However, the effects of lycopene on cytochrome P450 (CYP) enzymes or P-glycoprotein (P-gp) are not comprehensive. The present study was performed to investigate the effects of lycopene on the CYP enzymes and P-gp activity. A cocktail method was used to evaluate the activities of CYP3A4, CYP2C9, CYP2C19, CYP2D6 and CYP2E1. Caco-2 cell monolayer model was carried out to assay lycopene on P-gp activity. The results indicated that lycopene had a moderate inhibitory effect on CYP2E1, with IC50 value of 43.65 μM, whereas no inhibitory effects on CYP3A4, CYP2C19, CYP2D6 and CYP2E1, with IC50 values all over 100 μM. In addition, lycopene showed almost no inhibitory effect on rhodamine-123 efflux and uptake (p > .05), indicated no effects on P-gp activity. In conclusion, there should be required attention when lycopene are coadministered with other drugs that are metabolised by CYP2E1.

Screening for duplications, deletions and a common intronic mutation detects 35% of second mutations in patients with USH2A monoallelic mutations on Sanger sequencing.

Science.gov (United States)

Steele-Stallard, Heather B; Le Quesne Stabej, Polona; Lenassi, Eva; Luxon, Linda M; Claustres, Mireille; Roux, Anne-Francoise; Webster, Andrew R; Bitner-Glindzicz, Maria

2013-08-08

Usher Syndrome is the leading cause of inherited deaf-blindness. It is divided into three subtypes, of which the most common is Usher type 2, and the USH2A gene accounts for 75-80% of cases. Despite recent sequencing strategies, in our cohort a significant proportion of individuals with Usher type 2 have just one heterozygous disease-causing mutation in USH2A, or no convincing disease-causing mutations across nine Usher genes. The purpose of this study was to improve the molecular diagnosis in these families by screening USH2A for duplications, heterozygous deletions and a common pathogenic deep intronic variant USH2A: c.7595-2144A>G. Forty-nine Usher type 2 or atypical Usher families who had missing mutations (mono-allelic USH2A or no mutations following Sanger sequencing of nine Usher genes) were screened for duplications/deletions using the USH2A SALSA MLPA reagent kit (MRC-Holland). Identification of USH2A: c.7595-2144A>G was achieved by Sanger sequencing. Mutations were confirmed by a combination of reverse transcription PCR using RNA extracted from nasal epithelial cells or fibroblasts, and by array comparative genomic hybridisation with sequencing across the genomic breakpoints. Eight mutations were identified in 23 Usher type 2 families (35%) with one previously identified heterozygous disease-causing mutation in USH2A. These consisted of five heterozygous deletions, one duplication, and two heterozygous instances of the pathogenic variant USH2A: c.7595-2144A>G. No variants were found in the 15 Usher type 2 families with no previously identified disease-causing mutations. In 11 atypical families, none of whom had any previously identified convincing disease-causing mutations, the mutation USH2A: c.7595-2144A>G was identified in a heterozygous state in one family. All five deletions and the heterozygous duplication we report here are novel. This is the first time that a duplication in USH2A has been reported as a cause of Usher syndrome. We found that 8 of

SDHAF2 mutations in familial and sporadic paraganglioma and phaeochromocytoma.

Science.gov (United States)

Bayley, Jean-Pierre; Kunst, Henricus P M; Cascon, Alberto; Sampietro, Maria Lourdes; Gaal, José; Korpershoek, Esther; Hinojar-Gutierrez, Adolfo; Timmers, Henri J L M; Hoefsloot, Lies H; Hermsen, Mario A; Suárez, Carlos; Hussain, A Karim; Vriends, Annette H J T; Hes, Frederik J; Jansen, Jeroen C; Tops, Carli M; Corssmit, Eleonora P; de Knijff, Peter; Lenders, Jacques W M; Cremers, Cor W R J; Devilee, Peter; Dinjens, Winand N M; de Krijger, Ronald R; Robledo, Mercedes

2010-04-01

Paragangliomas and phaeochromocytomas are neuroendocrine tumours associated frequently with germline mutations of SDHD, SDHC, and SDHB. Previous studies have shown the imprinted SDHAF2 gene to be mutated in a large Dutch kindred with paragangliomas. We aimed to identify SDHAF2 mutation carriers, assess the clinical genetic significance of SDHAF2, and describe the associated clinical phenotype. We undertook a multicentre study in Spain and The Netherlands in 443 apparently sporadic patients with paragangliomas and phaeochromocytomas who did not have mutations in SDHD, SDHC, or SDHB. We analysed DNA of 315 patients for germline mutations of SDHAF2; a subset (n=200) was investigated for gross gene deletions. DNA from a group of 128 tumours was studied for somatic mutations. We also examined a Spanish family with head and neck paragangliomas with a young age of onset for the presence of SDHAF2 mutations, undertook haplotype analysis in this kindred, and assessed their clinical phenotype. We did not identify any germline or somatic mutations of SDHAF2, and no gross gene deletions were noted in the subset of apparently sporadic patients analysed. Investigation of the Spanish family identified a pathogenic germline DNA mutation of SDHAF2, 232G-->A (Gly78Arg), identical to the Dutch kindred. SDHAF2 mutations do not have an important role in phaeochromocytoma and are rare in head and neck paraganglioma. Identification of a second family with the Gly78Arg mutation suggests that this is a crucial residue for the function of SDHAF2. We conclude that SDHAF2 mutation analysis is justified in very young patients with isolated head and neck paraganglioma without mutations in SDHD, SDHC, or SDHB, and in individuals with familial antecedents who are negative for mutations in all other risk genes. Dutch Cancer Society, European Union 6th Framework Program, Fondo Investigaciones Sanitarias, Fundación Mutua Madrileña, and Red Temática de Investigación Cooperativa en Cáncer. 2010

Glycopeptide profiling of beta-2-glycoprotein I by mass spectrometry reveals attenuated sialylation in patients with antiphospholipid syndrome

DEFF Research Database (Denmark)

Kondo, Akira; Miyamoto, Toshiaki; Yonekawa, Osamu

2009-01-01

beta2-glycoprotein I (beta2GPI) is a five-domain protein associated with the antiphospholipid syndrome (APS), however, its normal biological function is yet to be defined. beta2GPI is N-glycosylated at several asparagine residues and the glycan moiety conjugated to residue 143 has been proposed t...

HER2 activating mutations are targets for colorectal cancer treatment.

Science.gov (United States)

Kavuri, Shyam M; Jain, Naveen; Galimi, Francesco; Cottino, Francesca; Leto, Simonetta M; Migliardi, Giorgia; Searleman, Adam C; Shen, Wei; Monsey, John; Trusolino, Livio; Jacobs, Samuel A; Bertotti, Andrea; Bose, Ron

2015-08-01

The Cancer Genome Atlas project identified HER2 somatic mutations and gene amplification in 7% of patients with colorectal cancer. Introduction of the HER2 mutations S310F, L755S, V777L, V842I, and L866M into colon epithelial cells increased signaling pathways and anchorage-independent cell growth, indicating that they are activating mutations. Introduction of these HER2 activating mutations into colorectal cancer cell lines produced resistance to cetuximab and panitumumab by sustaining MAPK phosphorylation. HER2 mutants are potently inhibited by low nanomolar doses of the irreversible tyrosine kinase inhibitors neratinib and afatinib. HER2 gene sequencing of 48 cetuximab-resistant, quadruple (KRAS, NRAS, BRAF, and PIK3CA) wild-type (WT) colorectal cancer patient-derived xenografts (PDX) identified 4 PDXs with HER2 mutations. HER2-targeted therapies were tested on two PDXs. Treatment with a single HER2-targeted drug (trastuzumab, neratinib, or lapatinib) delayed tumor growth, but dual HER2-targeted therapy with trastuzumab plus tyrosine kinase inhibitors produced regression of these HER2-mutated PDXs. HER2 activating mutations cause EGFR antibody resistance in colorectal cell lines, and PDXs with HER2 mutations show durable tumor regression when treated with dual HER2-targeted therapy. These data provide a strong preclinical rationale for clinical trials targeting HER2 activating mutations in metastatic colorectal cancer. ©2015 American Association for Cancer Research.

Solubilization of glycoproteins of envelope viruses by detergents

International Nuclear Information System (INIS)

Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

1986-01-01

The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-β-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines

Molecular cloning and mammalian expression of human beta 2-glycoprotein I cDNA

DEFF Research Database (Denmark)

Kristensen, Torsten; Schousboe, Inger; Boel, Espen

1991-01-01

Human β2-glycoprotein (β2gpI) cDNA was isolated from a liver cDNA library and sequenced. The cDNA encoded a 19-residue hydrophobic signal peptide followed by the mature β2gpI of 326 amino acid residues. In liver and in the hepatoma cell line HepG2 there are two mRNA species of about 1.4 and 4.3 kb......, respectively, hybridizing specifically with the β2gpI cDNA. Upon isoelectric focusing, recombinant β2gpI obtained from expression of β2gpI cDNA in baby hamster kidney cells showed the same pattern of bands as β2gpI isolated from plasma, and at least 5 polypeptides were visible...

Recurrent papillary craniopharyngioma with BRAFV600E mutation treated with neoadjuvant-targeted therapy.

Science.gov (United States)

Rostami, Elham; Witt Nyström, Petra; Libard, Sylwia; Wikström, Johan; Casar-Borota, Olivera; Gudjonsson, Olafur

2017-11-01

Craniopharyngiomas are histologically benign but locally aggressive tumors in the sellar region that may cause devastating neurological and endocrine deficits. They tend to recur following surgery with high morbidity; hence, postoperative radiotherapy is recommended following sub-total resection. BRAFV600E mutation is the principal oncogenic driver in the papillary variant of craniopharyngiomas. Recently, a dramatic tumor reduction has been reported in a patient with BRAFV600E mutated, multiply recurrent papillary craniopharyngioma using a combination therapy of BRAF inhibitor dabrafenib and MEK inhibitor trametinib. Here, we report on near-radical reduction of a growing residual BRAFV600E craniopharyngioma using the same neoadjuvant therapy.

Germline PMS2 mutation screened by mismatch repair protein immunohistochemistry of colorectal cancer in Japan.

Science.gov (United States)

Sugano, Kokichi; Nakajima, Takeshi; Sekine, Shigeki; Taniguchi, Hirokazu; Saito, Shinya; Takahashi, Masahiro; Ushiama, Mineko; Sakamoto, Hiromi; Yoshida, Teruhiko

2016-11-01

Germline PMS2 gene mutations were detected by RT-PCR/direct sequencing of total RNA extracted from puromycin-treated peripheral blood lymphocytes (PBL) and multiplex ligation-dependent probe amplification (MLPA) analyses of Japanese patients with colorectal cancer (CRC) fulfilling either the revised Bethesda Guidelines or being an age at disease onset of younger than 70 years, and screened by mismatch repair protein immunohistochemistry of formalin-fixed paraffin embedded sections. Of the 501 subjects examined, 7 (1.40%) showed the downregulated expression of the PMS2 protein alone and were referred to the genetic counseling clinic. Germline PMS2 mutations were detected in 6 (85.7%), including 3 nonsense and 1 frameshift mutations by RT-PCR/direct sequencing and 2 genomic deletions by MLPA. No mutations were identified in the other MMR genes (i.e. MSH2, MLH1 and MSH6). The prevalence of the downregulated expression of the PMS2 protein alone was 1.40% among the subjects examined and IHC results predicted the presence of PMS2 germline mutations. RT-PCR from puromycin-treated PBL and MLPA may be employed as the first screening step to detect PMS2 mutations without pseudogene interference, followed by the long-range PCR/nested PCR validation using genomic DNA. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

BRAFV600E mutation and its association with clinicopathological features of colorectal cancer: a systematic review and meta-analysis.

Science.gov (United States)

Chen, Dong; Huang, Jun-Fu; Liu, Kai; Zhang, Li-Qun; Yang, Zhao; Chuai, Zheng-Ran; Wang, Yun-Xia; Shi, Da-Chuan; Huang, Qing; Fu, Wei-Ling

2014-01-01

Colorectal cancer (CRC) is a heterogeneous disease with multiple underlying causative genetic mutations. The B-type Raf proto-oncogene (BRAF) plays an important role in the mitogen-activated protein kinase (MAPK) signaling cascade during CRC. The presence of BRAFV600E mutation can determine the response of a tumor to chemotherapy. However, the association between the BRAFV600E mutation and the clinicopathological features of CRC remains controversial. We performed a systematic review and meta-analysis to estimate the effect of BRAFV600E mutation on the clinicopathological characteristics of CRC. We identified studies that examined the effect of BRAFV600E mutation on CRC within the PubMed, ISI Science Citation Index, and Embase databases. The effect of BRAFV600E on outcome parameters was estimated by odds ratios (ORs) with 95% confidence intervals (CIs) for each study using a fixed effects or random effects model. 25 studies with a total of 11,955 CRC patients met inclusion criteria. The rate of BRAFV600 was 10.8% (1288/11955). The BRAFV600E mutation in CRC was associated with advanced TNM stage, poor differentiation, mucinous histology, microsatellite instability (MSI), CpG island methylator phenotype (CIMP). This mutation was also associated with female gender, older age, proximal colon, and mutL homolog 1 (MLH1) methylation. This meta-analysis demonstrated that BRAFV600E mutation was significantly correlated with adverse pathological features of CRC and distinct clinical characteristics. These data suggest that BRAFV600E mutation could be used to supplement standard clinical and pathological staging for the better management of individual CRC patients, and could be considered as a poor prognostic marker for CRC.

Apoptotic Activity of MeCP2 Is Enhanced by C-Terminal Truncating Mutations.

Directory of Open Access Journals (Sweden)

Alison A Williams

Full Text Available Methyl-CpG binding protein 2 (MeCP2 is a widely abundant, multifunctional protein most highly expressed in post-mitotic neurons. Mutations causing Rett syndrome and related neurodevelopmental disorders have been identified along the entire MECP2 locus, but symptoms vary depending on mutation type and location. C-terminal mutations are prevalent, but little is known about the function of the MeCP2 C-terminus. We employ the genetic efficiency of Drosophila to provide evidence that expression of p.Arg294* (more commonly identified as R294X, a human MECP2 E2 mutant allele causing truncation of the C-terminal domains, promotes apoptosis of identified neurons in vivo. We confirm this novel finding in HEK293T cells and then use Drosophila to map the region critical for neuronal apoptosis to a small sequence at the end of the C-terminal domain. In vitro studies in mammalian systems previously indicated a role of the MeCP2 E2 isoform in apoptosis, which is facilitated by phosphorylation at serine 80 (S80 and decreased by interactions with the forkhead protein FoxG1. We confirm the roles of S80 phosphorylation and forkhead domain transcription factors in affecting MeCP2-induced apoptosis in Drosophila in vivo, thus indicating mechanistic conservation between flies and mammalian cells. Our findings are consistent with a model in which C- and N-terminal interactions are required for healthy function of MeCP2.

Novel insertion mutation of ABCB1 gene in an ivermectin-sensitive Border Collie

OpenAIRE

Han, Jae-Ik; Son, Hyoung-Won; Park, Seung-Cheol; Na, Ki-Jeong

2010-01-01

P-glycoprotein (P-gp) is encoded by the ABCB1 gene and acts as an efflux pump for xenobiotics. In the Border Collie, a nonsense mutation caused by a 4-base pair deletion in the ABCB1 gene is associated with a premature stop to P-gp synthesis. In this study, we examined the full-length coding sequence of the ABCB1 gene in an ivermectin-sensitive Border Collie that lacked the aforementioned deletion mutation. The sequence was compared to the corresponding sequences of a wild-type Beagle and sev...

The rad2 mutation affects the molecular nature of UV and acridine-mustard-induced mutations in the ADE2 gene of Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Ivanov, E.L.; Kovaltzova, S.V.; Kassinova, G.V.; Gracheva, L.M.; Korolev, V.G.; Zakharov, I.A.

1986-01-01

The authors have studied the molecular nature of ade2 mutations induced by UV light and bifunctional acridine-mustard (BAM) in wild-type (RAD) and in excision-deficient (rad2) strains of the yeast, Saccharomyces cerevisiae. In the RAD strain, UV causes 45% GC → AT transitions among all mutations; in the rad2 strain this value is 77%. BAM was shown to be highly specific for frameshift mutagenesis: 60% frameshifts in the RAD strain, and as many as 84% frameshifts in the rad2 strain were induced. Therefore, the rad2 mutation affects the specificity of UV- and BAM-induced mutagenesis in yeast. Experimental data agree with the view that the majority of mutations in the RAD strain are induced by a prereplicative mechanism, whereas mutations in the rad2 strain are predominantly postreplicative events. (Auth.)

A single site for N-linked glycosylation in the envelope glycoprotein of feline immunodeficiency virus modulates the virus-receptor interaction

Directory of Open Access Journals (Sweden)

Samman Ayman

2008-08-01

Full Text Available Abstract Feline immunodeficiency virus (FIV targets helper T cells by attachment of the envelope glycoprotein (Env to CD134, a subsequent interaction with CXCR4 then facilitating the process of viral entry. As the CXCR4 binding site is not exposed until CD134-binding has occurred then the virus is protected from neutralising antibodies targeting the CXCR4-binding site on Env. Prototypic FIV vaccines based on the FL4 strain of FIV contain a cell culture-adapted strain of FIV Petaluma, a CD134-independent strain of FIV that interacts directly with CXCR4. In addition to a characteristic increase in charge in the V3 loop homologue of FIVFL4, we identified two mutations in potential sites for N-linked glycosylation in the region of FIV Env analogous to the V1–V2 region of HIV and SIV Env, T271I and N342Y. When these mutations were introduced into the primary GL8 and CPG41 strains of FIV, the T271I mutation was found to alter the nature of the virus-CD134 interaction; primary viruses carrying the T271I mutation no longer required determinants in cysteine-rich domain (CRD 2 of CD134 for viral entry. The T271I mutation did not confer CD134-independent infection upon GL8 or CPG41, nor did it increase the affinity of the CXCR4 interaction, suggesting that the principal effect was targeted at reducing the complexity of the Env-CD134 interaction.

Germ-line PHD1 and PHD2 mutations detected in patients with pheochromocytoma/paraganglioma-polycythemia.

Science.gov (United States)

Yang, Chunzhang; Zhuang, Zhengping; Fliedner, Stephanie M J; Shankavaram, Uma; Sun, Michael G; Bullova, Petra; Zhu, Roland; Elkahloun, Abdel G; Kourlas, Peter J; Merino, Maria; Kebebew, Electron; Pacak, Karel

2015-01-01

We have investigated genetic/pathogenetic factors associated with a new clinical entity in patients presenting with pheochromocytoma/paraganglioma (PHEO/PGL) and polycythemia. Two patients without hypoxia-inducible factor 2α (HIF2A) mutations, who presented with similar clinical manifestations, were analyzed for other gene mutations, including prolyl hydroxylase (PHD) mutations. We have found for the first time a germ-line mutation in PHD1 in one patient and a novel germ-line PHD2 mutation in a second patient. Both mutants exhibited reduced protein stability with substantial quantitative protein loss and thus compromised catalytic activities. Due to the unique association of patients' polycythemia with borderline or mildly elevated erythropoietin (EPO) levels, we also performed an in vitro sensitivity assay of erythroid progenitors to EPO and for EPO receptor (EPOR) expression. The results show inappropriate hypersensitivity of erythroid progenitors to EPO in these patients, indicating increased EPOR expression/activity. In addition, the present study indicates that HIF dysregulation due to PHD mutations plays an important role in the pathogenesis of these tumors and associated polycythemia. The PHD1 mutation appears to be a new member contributing to the genetic landscape of this novel clinical entity. Our results support the existence of a specific PHD1- and PHD2-associated PHEO/PGL-polycythemia disorder. • A novel germ-l i n e PHD1 mutation causing heochromocytoma/paraganglioma and polycythemia. • Increased EPOR activity and inappropriate hypersensitivity of erythroid progenitors to EPO.

Studies on pregnancy associated alpha2-glycoprotein (alpha2-PAG) in screening of malignant tumors

International Nuclear Information System (INIS)

Akiyama, Mitoshi; Hoshiga, Noriko; Kobuke, Kyoko; Kyoizume, Seishi; Hakoda, Masayuki

1984-01-01

The measurement of α 2 -glycoprotein (α 2 -PAG) by enzyme immunoassay (EIA) method was established and its clinical significance was studied. The normal value of serum α 2 -PAG was 2.7+-3.7 μg/ml in men and 8.7+-9.8 μg/ml in women. However, significant difference was observed according to the presence of pregnancy history. α 2 -PAG was significantly higher in male patients with lung cancer (a mean of 18.2+-18.6 μg/ml or other cancers (a mean of 12.4+-12.8 μg/ml) than in norm al male people. One of the tumor markers, such as α 2 -PAG, CEA, AFP and ferritin, or more showed an abnormal value in many of the patients with malignant tumors. One marker or more were also abnormal in 128 of 428 atomic bomb survivors (29.9%), of whom 23 (18%) had abnormal values in two or more markers. (Namekawa, K.)

BRAFV600E mutation and its association with clinicopathological features of colorectal cancer: a systematic review and meta-analysis.

Directory of Open Access Journals (Sweden)

Dong Chen

Full Text Available BACKGROUND: Colorectal cancer (CRC is a heterogeneous disease with multiple underlying causative genetic mutations. The B-type Raf proto-oncogene (BRAF plays an important role in the mitogen-activated protein kinase (MAPK signaling cascade during CRC. The presence of BRAFV600E mutation can determine the response of a tumor to chemotherapy. However, the association between the BRAFV600E mutation and the clinicopathological features of CRC remains controversial. We performed a systematic review and meta-analysis to estimate the effect of BRAFV600E mutation on the clinicopathological characteristics of CRC. METHODS: We identified studies that examined the effect of BRAFV600E mutation on CRC within the PubMed, ISI Science Citation Index, and Embase databases. The effect of BRAFV600E on outcome parameters was estimated by odds ratios (ORs with 95% confidence intervals (CIs for each study using a fixed effects or random effects model. RESULTS: 25 studies with a total of 11,955 CRC patients met inclusion criteria. The rate of BRAFV600 was 10.8% (1288/11955. The BRAFV600E mutation in CRC was associated with advanced TNM stage, poor differentiation, mucinous histology, microsatellite instability (MSI, CpG island methylator phenotype (CIMP. This mutation was also associated with female gender, older age, proximal colon, and mutL homolog 1 (MLH1 methylation. CONCLUSIONS: This meta-analysis demonstrated that BRAFV600E mutation was significantly correlated with adverse pathological features of CRC and distinct clinical characteristics. These data suggest that BRAFV600E mutation could be used to supplement standard clinical and pathological staging for the better management of individual CRC patients, and could be considered as a poor prognostic marker for CRC.

Serum AMH levels in healthy women from BRCA1/2 mutated families: are they reduced?

Science.gov (United States)

van Tilborg, Theodora C; Derks-Smeets, Inge A P; Bos, Anna M E; Oosterwijk, Jan C; van Golde, Ron J; de Die-Smulders, Christine E; van der Kolk, Lizet E; van Zelst-Stams, Wendy A G; Velthuizen, Maria E; Hoek, Annemieke; Eijkemans, Marinus J C; Laven, Joop S E; Ausems, Margreet G E M; Broekmans, Frank J M

2016-11-01

were relatively young. Power was insufficient to analyze BRCA1 and BRCA2 mutation carriers separately. AMH levels may have been influenced by the use of hormonal contraceptives, though similar proportions of carriers and non-carriers were current users and adjustments were made to correct for potential confounding in our analysis. Limitations of the current analysis and limitations of the existing literature argue for prospective, well-controlled follow-up studies with recurrent AMH measurements to determine whether carriers might be at risk for low ovarian reserve and to definitively guide care. This study was partially financially supported by a personal grant for Inge A.P. Derks-Smeets, kindly provided by the Dutch Cancer Society (Grant Number UM 2011-5249). Theodora C. van Tilborg, Inge A.P. Derks-Smeets, Anna M.E. Bos, Jan C. Oosterwijk, Christine E. de Die-Smulders, Lizet E. van der Kolk, Wendy A.G. van Zelst-Stams, Maria E. Velthuizen, Marinus J.C. Eijkemans and Margreet G.E.M. Ausems have nothing to disclose. Ron J. van Golde has received unrestricted research grants from Ferring and Merck Serono, outside the submitted work. Annemieke Hoek received an unrestricted educational grant from Ferring pharmaceutical BV, The Netherlands and a speaker's fee for post graduate education from MSD pharmaceutical company, outside the submitted work. Joop S.E. Laven has received unrestricted research grants from Ferring, Merck Serono, Merck Sharpe & Dome, Organon, and Schering Plough, outside the submitted work. Frank J.M. Broekmans is a member of the external advisory board for Merck Serono (The Netherlands), outside the submitted work. NTR no. 4324. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Humoral immune response to hypervariable region 1 of the putative envelope glycoprotein (gp70) of hepatitis C virus.

OpenAIRE

Kato, N; Sekiya, H; Ootsuyama, Y; Nakazawa, T; Hijikata, M; Ohkoshi, S; Shimotohno, K

1993-01-01

We recently found that alterations of amino acids in hypervariable region 1 (HVR1) of the putative envelope glycoprotein (gp70) of hepatitis C virus (HCV) occurred sequentially in the chronic phase of hepatitis at intervals of several months. This finding suggests that mutations in HVR1 are involved in the mechanism of persistent chronic HCV infection involving escape from the immunosurveillance system. To explore this possibility, we examined the humoral immune response to HVR1 with our assa...

Motor pathway excitability in ATP13A2 mutation carriers

DEFF Research Database (Denmark)

Zittel, S; Kroeger, J; van der Vegt, J P M

2012-01-01

OBJECTIVE: To describe excitability of motor pathways in Kufor-Rakeb syndrome (PARK9), an autosomal recessive nigro-striatal-pallidal-pyramidal neurodegeneration caused by a mutation in the ATP13A2 gene, using transcranial magnetic stimulation (TMS). METHODS: Five members of a Chilean family...... with an ATP13A2 mutation (one affected mutation carrier (MC) with a compound heterozygous mutation, 4 asymptomatic MC with a single heterozygous mutation) and 11 healthy subjects without mutations were studied. We measured motor evoked potentials (MEP), the contralateral silent period (cSP), short interval....... RESULTS: CSP duration was increased in the symptomatic ATP13A2 MC. The iSP measurements revealed increased interhemispheric inhibition in both the compound heterozygous and the heterozygous MC. CONCLUSION: A compound heterozygous mutation in the ATP13A2 gene is associated with increased intracortical...

The Role of Turmerones on Curcumin Transportation and P-Glycoprotein Activities in Intestinal Caco-2 Cells

Science.gov (United States)

Yue, Grace G.L.; Cheng, Sau-Wan; Yu, Hua; Xu, Zi-Sheng; Lee, Julia K.M.; Hon, Po-Ming; Lee, Mavis Y.H.; Kennelly, Edward J.; Deng, Gary; Yeung, Simon K.; Cassileth, Barrie R.; Fung, Kwok-Pui; Leung, Ping-Chung

2012-01-01

Abstract The rhizome of Curcuma longa (turmeric) is often used in Asia as a spice and as a medicine. Its most well-studied component, curcumin, has been shown to exhibit poor bioavailability in animal studies and clinical trials. We hypothesized that the presence of lipophilic components (e.g., turmerones) in turmeric extract would affect the absorption of curcumin. The effects of turmerones on curcumin transport were evaluated in human intestinal epithelial Caco-2 cells. The roles of turmerones on P-glycoprotein (P-gp) activities and mRNA expression were also evaluated. Results showed that in the presence of α- and aromatic turmerones, the amount of curcumin transported into the Caco-2 cells in 2 hours was significantly increased. α-Turmerone and verapamil (a P-gp inhibitor) significantly inhibited the efflux of rhodamine-123 and digoxin (i.e., inhibited the activity of P-gp). It is interesting that aromatic turmerone significantly increased the rhodamine-123 efflux and P-gp (MDR1 gene) mRNA expression levels. The effects of α- and aromatic turmerones on curcumin transport as well as P-gp activities were shown here for the first time. The presence of turmerones did affect the absorption of curcumin in vitro. These findings suggest the potential use of turmeric extract (including curcumin and turmerones), rather than curcumin alone, for treating diseases. PMID:22181075

The role of turmerones on curcumin transportation and P-glycoprotein activities in intestinal Caco-2 cells.

Science.gov (United States)

Yue, Grace G L; Cheng, Sau-Wan; Yu, Hua; Xu, Zi-Sheng; Lee, Julia K M; Hon, Po-Ming; Lee, Mavis Y H; Kennelly, Edward J; Deng, Gary; Yeung, Simon K; Cassileth, Barrie R; Fung, Kwok-Pui; Leung, Ping-Chung; Lau, Clara B S

2012-03-01

The rhizome of Curcuma longa (turmeric) is often used in Asia as a spice and as a medicine. Its most well-studied component, curcumin, has been shown to exhibit poor bioavailability in animal studies and clinical trials. We hypothesized that the presence of lipophilic components (e.g., turmerones) in turmeric extract would affect the absorption of curcumin. The effects of turmerones on curcumin transport were evaluated in human intestinal epithelial Caco-2 cells. The roles of turmerones on P-glycoprotein (P-gp) activities and mRNA expression were also evaluated. Results showed that in the presence of α- and aromatic turmerones, the amount of curcumin transported into the Caco-2 cells in 2 hours was significantly increased. α-Turmerone and verapamil (a P-gp inhibitor) significantly inhibited the efflux of rhodamine-123 and digoxin (i.e., inhibited the activity of P-gp). It is interesting that aromatic turmerone significantly increased the rhodamine-123 efflux and P-gp (MDR1 gene) mRNA expression levels. The effects of α- and aromatic turmerones on curcumin transport as well as P-gp activities were shown here for the first time. The presence of turmerones did affect the absorption of curcumin in vitro. These findings suggest the potential use of turmeric extract (including curcumin and turmerones), rather than curcumin alone, for treating diseases.

Glycoprotein of the wall of sycamore tissue-culture cells.

Science.gov (United States)

Heath, M F; Northcote, D H

1971-12-01

1. A glycoprotein containing a large amount of hydroxyproline is present in the cell walls of sycamore callus cells. This protein is insoluble and remained in the alpha-cellulose when a mild separation procedure was used to obtain the polysaccharide fractions of the wall. The glycoprotein contained a high proportion of arabinose and galactose. 2. Soluble glycopeptides were prepared from the alpha-cellulose fraction when peptide bonds were broken by hydrazinolysis. The soluble material was fractionated by gel filtration and one glycopeptide was further purified by electrophoresis; it had a composition of 10% hydroxyproline, 35% arabinose and 55% galactose, and each hydroxyproline residue carried a glycosyl radical so that the oligosaccharides on the glycopeptide had an average degree of polymerization of 9. 3. The extraction of the glycopeptides was achieved without cleavage of glycosyl bonds, so that the glycoprotein cannot act as a covalent cross-link between the major polysaccharides of the wall. 4. The wall protein approximates in conformation to polyhydroxyproline and therefore it probably has similar physicochemical properties to polyhydroxyproline. This is discussed in relation to the function of the glycoprotein and its effect on the physical and chemical nature of the wall.

Characterization of pH-sensitive molecular switches that trigger the structural transition of vesicular stomatitis virus glycoprotein from the postfusion state toward the prefusion state.

Science.gov (United States)

Ferlin, Anna; Raux, Hélène; Baquero, Eduard; Lepault, Jean; Gaudin, Yves

2014-11-01

Vesicular stomatitis virus (VSV; the prototype rhabdovirus) fusion is triggered at low pH and mediated by glycoprotein G, which undergoes a low-pH-induced structural transition. A unique feature of rhabdovirus G is that its conformational change is reversible. This allows G to recover its native prefusion state at the viral surface after its transport through the acidic Golgi compartments. The crystal structures of G pre- and postfusion states have been elucidated, leading to the identification of several acidic amino acid residues, clustered in the postfusion trimer, as potential pH-sensitive switches controlling the transition back toward the prefusion state. We mutated these residues and produced a panel of single and double mutants whose fusion properties, conformational change characteristics, and ability to pseudotype a virus lacking the glycoprotein gene were assayed. Some of these mutations were also introduced in the genome of recombinant viruses which were further characterized. We show that D268, located in the segment consisting of residues 264 to 273, which refolds into postfusion helix F during G structural transition, is the major pH sensor while D274, D395, and D393 have additional contributions. Furthermore, a single passage of recombinant virus bearing the mutation D268L (which was demonstrated to stabilize the G postfusion state) resulted in a pseudorevertant with a compensatory second mutation, L271P. This revealed that the propensity of the segment of residues 264 to 273 to refold into helix F has to be finely tuned since either an increase (mutation D268L alone) or a decrease (mutation L271P alone) of this propensity is detrimental to the virus. Vesicular stomatitis virus enters cells via endocytosis. Endosome acidification induces a structural transition of its unique glycoprotein (G), which mediates fusion between viral and endosomal membranes. G conformational change is reversible upon increases in pH. This allows G to recover its native

Insight into resistance mechanisms of AZD4547 and E3810 to FGFR1 gatekeeper mutation via theoretical study

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Liang D

2017-02-01

Full Text Available Donglou Liang,1,* Qiaowan Chen,2,* Yujin Guo,1 Ting Zhang,3 Wentao Guo4 1Pharmacy Department, Jining First People’s Hospital, 2Department of Obstetrics, Affiliated Hospital of Jining Medical University, Jining, Shandong, 3Department of Rheumatology, The First Affiliated Hospital of Wenzhou Medical University, 4School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China *These authors contributed equally to this work Abstract: Inhibitors targeting the amplification of the fibroblast growth factor receptor 1 (FGFR1 have found success in the treatment of FGFR1-positive squamous cell lung and breast cancers. A secondary mutation of gatekeeper residue (V561M in the binding site has been linked to the acquired resistance. Recently, two well-known small molecule inhibitors of FGFR1, AZD4547 and E3810, reported that the V561M mutation confers significant resistance to E3810, while retaining affinity for AZD4547. FGFR1 is widely investigated as potential therapeutic target, while there are few computational studies made to understand the resistance mechanisms about FGFR1 V561M gatekeeper mutation. In this study, molecular docking, classical molecular dynamics simulations, molecular mechanics/generalized born surface area (MM/GBSA free energy calculations, and umbrella sampling (US simulations were carried out to make clear the principle of the binding preference of AZD4547 and E3810 toward FGFR1 V561M gatekeeper mutation. The results provided by MM/GBSA reveal that AZD4547 has similar binding affinity to both FGFR1WT and FGFR1V561M, whereas E3810 has much higher binding affinity to FGFR1WT than to FGFR1V561M. Comparison of individual energy terms indicates that the major variation of E3810 between FGFR1WT and FGFR1V561M are van der Waals interactions. In addition, US simulations prove that the potential of mean force (PMF profile of AZD4547 toward FGFR1WT and FGFR1V561M has similar PMF depth. However, the PMF profile

3,3′,4,4′,5-Pentachlorobiphenyl Inhibits Drug Efflux Through P-Glycoprotein in KB-3 Cells Expressing Mutant Human P-Glycoprotein

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Hiroshi Fujise

2004-01-01

Full Text Available The effects on the drug efflux of 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126, the most toxic of all coplanar polychlorinated biphenyls (Co-PCBs, were examined in KB-3 cells expressing human wild-type and mutant P-glycoprotein in which the 61st amino acid was substituted for serine or phenylalanine (KB3-Phe61. In the cells expressing P-glycoproteins, accumulations of vinblastine and colchicine decreased form 85% to 92% and from 62% to 91%, respectively, and the drug tolerances for these chemicals were increased. In KB3-Phe61, the decreases in drug accumulation were inhibited by adding PCB-126 in a way similar to that with cyclosporine A: by adding 1 μM PCB-126, the accumulations of vinblastine and colchicine increased up to 3.3- and 2.3-fold, respectively. It is suggested that PCB-126 decreased the drug efflux by inhibiting the P-glycoprotein in KB3-Phe61. Since there were various P-glycoproteins and many congeners of Co-PCBs, this inhibition has to be considered a new cause of the toxic effects of Co-PCBs.

Novel USH2A compound heterozygous mutations cause RP/USH2 in a Chinese family.

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Liu, Xiaowen; Tang, Zhaohui; Li, Chang; Yang, Kangjuan; Gan, Guanqi; Zhang, Zibo; Liu, Jingyu; Jiang, Fagang; Wang, Qing; Liu, Mugen

2010-03-17

To identify the disease-causing gene in a four-generation Chinese family affected with retinitis pigmentosa (RP). Linkage analysis was performed with a panel of microsatellite markers flanking the candidate genetic loci of RP. These loci included 38 known RP genes. The complete coding region and exon-intron boundaries of Usher syndrome 2A (USH2A) were sequenced with the proband DNA to screen the disease-causing gene mutation. Restriction fragment length polymorphism (RFLP) analysis and direct DNA sequence analysis were done to demonstrate co-segregation of the USH2A mutations with the family disease. One hundred normal controls were used without the mutations. The disease-causing gene in this Chinese family was linked to the USH2A locus on chromosome 1q41. Direct DNA sequence analysis of USH2A identified two novel mutations in the patients: one missense mutation p.G1734R in exon 26 and a splice site mutation, IVS32+1G>A, which was found in the donor site of intron 32 of USH2A. Neither the p.G1734R nor the IVS32+1G>A mutation was found in the unaffected family members or the 100 normal controls. One patient with a homozygous mutation displayed only RP symptoms until now, while three patients with compound heterozygous mutations in the family of study showed both RP and hearing impairment. This study identified two novel mutations: p.G1734R and IVS32+1G>A of USH2A in a four-generation Chinese RP family. In this study, the heterozygous mutation and the homozygous mutation in USH2A may cause Usher syndrome Type II or RP, respectively. These two mutations expand the mutant spectrum of USH2A.

JAK2 mutations and clinical practice in myeloproliferative neoplasms.

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Tefferi, Ayalew

2007-01-01

With the discovery in the last 3 years of novel Janus kinase 2 (JAK2) and thrombopoietin receptor (MPL) mutations, the pathogenetic understanding of and clinical practice for myeloproliferative neoplasms (MPNs) have entered a new era. Each one of these newly discovered mutations, including JAK2V617F, MPLW515L, and a JAK2 exon 12 mutation, has been shown to result in constitutive activation of JAK-STAT signaling and also induce a MPN phenotype in mice. Thus, JAK2 is now considered to be a legitimate target for drug development in MPNs, and small molecule JAK2 inhibitors have already gone through successful preclinical testing, and early-phase human trials in primary myelofibrosis have already begun. Furthermore, JAK2 mutation screening has now become a front-line diagnostic test in the evaluation of both "erythrocytosis" and thrombocytosis and the 2001 World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis have now been revised to incorporate JAK2V617F mutation screening.

Value of TIRADS, BSRTC and FNA-BRAF V600E mutation analysis in differentiating high-risk thyroid nodules.

Science.gov (United States)

Zhang, Yu-zhi; Xu, Ting; Cui, Dai; Li, Xiao; Yao, Qing; Gong, Hai-yan; Liu, Xiao-yun; Chen, Huan-huan; Jiang, Lin; Ye, Xin-hua; Zhang, Zhi-hong; Shen, Mei-ping; Duan, Yu; Yang, Tao; Wu, Xiao-hong

2015-11-24

The thyroid imaging reporting and data system (TIRADS) and Bethesda system for reporting thyroid cytopathology (BSRTC) have been used for interpretation of ultrasound and fine-needle aspiration cytology (FNAC) results of thyroid nodules. BRAF(V600E) mutation analysis is a molecular tool in diagnosing thyroid carcinoma. Our objective was to compare the diagnostic value of these methods in differentiating high-risk thyroid nodules. Total 220 patients with high-risk thyroid nodules were recruited in this prospective study. They all underwent ultrasound, FNAC and BRAF(V600E) mutation analysis. The sensitivity and specificity of TIRADS were 73.1% and 88.4%. BSRTC had higher specificity (97.7%) and similar sensitivity (77.6%) compared with TIRADS. The sensitivity and specificity of BRAF(V600E) mutation (85.1%, 100%) were the highest. The combination of BSRTC and BRAF(V600E) mutation analysis significantly increased the efficiency, with 97.8% sensitivity, 97.7% specificity. In patients with BSRTC I-III, the mutation rate of BRAF(V600E) was 64.5% in nodules with TIRADS 4B compared with 8.4% in nodules with TIRADS 3 or 4A (P value in differentiating high-risk thyroid nodules. The TIRADS is useful in selecting high-risk patients for FNAB and patients with BSRTC I-III for BRAF(V600E) mutation analysis.

BRAFV600E mutation analysis in patients with metastatic colorectal cancer (mCRC in daily clinical practice: correlations with clinical characteristics, and its impact on patients' outcome.

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Zacharenia Saridaki

Full Text Available To prospectively evaluate the usefulness of the BRAFV600E mutation detection in daily clinical practice in patients with metastatic Colorectal Cancer (mCRC.504 mCRC patients treated with systemic chemotherapy ± biologics were analyzed.A statistically significant higher incidence of the BRAF mutation was observed in patients with ECOG-PS 2 (p=0.001, multiple metastatic sites (p=0.002,> 65 years old (p=0.004, primary tumors located in the colon (p<0.001, high-grade tumors (p=0.001 and in those with mucinous features (p=0.037. Patients with BRAFV600E mutated tumors had a statistically significantly reduced progression-free survival (PFS compared to wild-type (wt ones (4.1 and 11.6 months, respectively; p<0.001 and overall survival (OS (14.0 vs. 34.6 months, respectively; p<0.001. In the multivariate analysis the BRAFV600E mutation emerged as an independent factor associated with reduced PFS (HR: 4.1, 95% CI 2.7-6.2; p<0.001 and OS (HR: 5.9, 95% CI 3.7-9.5; p<0.001. Among the 273 patients treated with salvage cetuximab or panitumumab, the BRAFV600E mutation was correlated with reduced PFS (2.2 vs. 6.0 months; p<0.0001 and OS (4.3 vs. 17.4 months; p<0.0001.The presence of BRAFV600E-mutation in mCRC characterizes a subgroup of patients with distinct biologic, clinical and pathological features and is associated with very poor patients' prognosis.

GlycA, a marker of acute phase glycoproteins, and the risk of incident type 2 diabetes mellitus : PREVEND study

NARCIS (Netherlands)

Connelly, Margery A.; Gruppen, Eke G.; Wolak-Dinsmore, Justyna; Matyus, Steven P.; Riphagen, Ineke J.; Shalaurova, Irina; Bakker, Stephan J. L.; Otvos, James D.; Dullaart, Robin P. F.

2016-01-01

Background: GlycA is a recently developed glycoprotein biomarker of systemic inflammation that may be predictive of incident type 2 diabetes mellitus (T2DM). Methods: Analytical performance of the GlycA test, measured on the Vantera (R) Clinical Analyzer, was evaluated. To test its prospective

Mutational spectrum of the WFS1 gene in Wolfram syndrome, nonsyndromic hearing impairment, diabetes mellitus, and psychiatric disease

NARCIS (Netherlands)

Cryns, K; Sivakumaran, TA; Van den Ouweland, JMW; Pennings, RJE; Cremers, CWRJ; Flothmann, K; Young, TL; Smith, RJH; Lesperance, MM; Van Camp, G

2003-01-01

WFS1 is a novel gene and encodes an 890 amino-acid glycoprotein (wolframin), predominantly localized in the endoplasmic reticulum. Mutations in WFS1 underlie autosomal recessive Wolfram syndrome and autosomal dominant low frequency sensorineural hearing impairment (LFSNHI) DFNA6/14. In addition,

Mutational spectrum of the WFS1 gene in Wolfram syndrome, nonsyndromic hearing impairment, diabetes mellitus, and psychiatric disease.

NARCIS (Netherlands)

Cryns, K.; Sivakumaran, T.A.; Ouweland, J.M.W. van den; Pennings, R.J.E.; Cremers, C.W.R.J.; Flothmann, K.; Young, T.L.; Smith, R.J.H.; Lesperance, M.M.; Camp, G. van

2003-01-01

WFS1 is a novel gene and encodes an 890 amino-acid glycoprotein (wolframin), predominantly localized in the endoplasmic reticulum. Mutations in WFS1 underlie autosomal recessive Wolfram syndrome and autosomal dominant low frequency sensorineural hearing impairment (LFSNHI) DFNA6/14. In addition,

Functional Role of N-Linked Glycosylation in Pseudorabies Virus Glycoprotein gH.

Science.gov (United States)

Vallbracht, Melina; Rehwaldt, Sascha; Klupp, Barbara G; Mettenleiter, Thomas C; Fuchs, Walter

2018-05-01

Many viral envelope proteins are modified by asparagine (N)-linked glycosylation, which can influence their structure, physicochemical properties, intracellular transport, and function. Here, we systematically analyzed the functional relevance of N-linked glycans in the alphaherpesvirus pseudorabies virus (PrV) glycoprotein H (gH), which is an essential component of the conserved core herpesvirus fusion machinery. Upon gD-mediated receptor binding, the heterodimeric complex of gH and gL activates gB to mediate fusion of the viral envelope with the host cell membrane for viral entry. gH contains five potential N-linked glycosylation sites at positions 77, 162, 542, 604, and 627, which were inactivated by conservative mutations (asparagine to glutamine) singly or in combination. The mutated proteins were tested for correct expression and fusion activity. Additionally, the mutated gH genes were inserted into the PrV genome for analysis of function during virus infection. Our results demonstrate that all five sites are glycosylated. Inactivation of the PrV-specific N77 or the conserved N627 resulted in significantly reduced in vitro fusion activity, delayed penetration kinetics, and smaller virus plaques. Moreover, substitution of N627 greatly affected transport of gH in transfected cells, resulting in endoplasmic reticulum (ER) retention and reduced surface expression. In contrast, mutation of N604, which is conserved in the Varicellovirus genus, resulted in enhanced in vitro fusion activity and viral cell-to-cell spread. These results demonstrate a role of the N-glycans in proper localization and function of PrV gH. However, even simultaneous inactivation of all five N-glycosylation sites of gH did not severely inhibit formation of infectious virus particles. IMPORTANCE Herpesvirus infection requires fusion of the viral envelope with cellular membranes, which involves the conserved fusion machinery consisting of gB and the heterodimeric gH/gL complex. The bona fide

Initiating a watch list for Ebola virus antibody escape mutations

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Craig R. Miller

2016-02-01

Full Text Available The 2014 Ebola virus (EBOV outbreak in West Africa is the largest in recorded history and resulted in over 11,000 deaths. It is essential that strategies for treatment and containment be developed to avoid future epidemics of this magnitude. With the development of vaccines and antibody-based therapies using the envelope glycoprotein (GP of the 1976 Mayinga strain, one important strategy is to anticipate how the evolution of EBOV might compromise these efforts. In this study we have initiated a watch list of potential antibody escape mutations of EBOV by modeling interactions between GP and the antibody KZ52. The watch list was generated using molecular modeling to estimate stability changes due to mutation. Every possible mutation of GP was considered and the list was generated from those that are predicted to disrupt GP-KZ52 binding but not to disrupt the ability of GP to fold and to form trimers. The resulting watch list contains 34 mutations (one of which has already been seen in humans at six sites in the GP2 subunit. Should mutations from the watch list appear and spread during an epidemic, it warrants attention as these mutations may reflect an evolutionary response from the virus that could reduce the effectiveness of interventions such as vaccination. However, this watch list is incomplete and emphasizes the need for more experimental structures of EBOV interacting with antibodies in order to expand the watch list to other epitopes. We hope that this work provokes experimental research on evolutionary escape in both Ebola and other viral pathogens.

Initiating a watch list for Ebola virus antibody escape mutations.

Science.gov (United States)

Miller, Craig R; Johnson, Erin L; Burke, Aran Z; Martin, Kyle P; Miura, Tanya A; Wichman, Holly A; Brown, Celeste J; Ytreberg, F Marty

2016-01-01

The 2014 Ebola virus (EBOV) outbreak in West Africa is the largest in recorded history and resulted in over 11,000 deaths. It is essential that strategies for treatment and containment be developed to avoid future epidemics of this magnitude. With the development of vaccines and antibody-based therapies using the envelope glycoprotein (GP) of the 1976 Mayinga strain, one important strategy is to anticipate how the evolution of EBOV might compromise these efforts. In this study we have initiated a watch list of potential antibody escape mutations of EBOV by modeling interactions between GP and the antibody KZ52. The watch list was generated using molecular modeling to estimate stability changes due to mutation. Every possible mutation of GP was considered and the list was generated from those that are predicted to disrupt GP-KZ52 binding but not to disrupt the ability of GP to fold and to form trimers. The resulting watch list contains 34 mutations (one of which has already been seen in humans) at six sites in the GP2 subunit. Should mutations from the watch list appear and spread during an epidemic, it warrants attention as these mutations may reflect an evolutionary response from the virus that could reduce the effectiveness of interventions such as vaccination. However, this watch list is incomplete and emphasizes the need for more experimental structures of EBOV interacting with antibodies in order to expand the watch list to other epitopes. We hope that this work provokes experimental research on evolutionary escape in both Ebola and other viral pathogens.

Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations

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Diaz-Llopis Manuel

2011-10-01

Full Text Available Abstract Background Usher Syndrome type II (USH2 is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP. Among the three genes implicated, mutations in the USH2A gene account for 74-90% of the USH2 cases. Methods To identify the genetic cause of the disease and determine the frequency of USH2A mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing. Results As a result, a total of 144 DNA sequence variants were identified. Based upon previous studies, allele frequencies, segregation analysis, bioinformatics' predictions and in vitro experiments, 37 variants (23 of them novel were classified as pathogenic mutations. Conclusions This report provide a wide spectrum of USH2A mutations and clinical features, including atypical Usher syndrome phenotypes resembling Usher syndrome type I. Considering only the patients clearly diagnosed with Usher syndrome type II, and results obtained in this and previous studies, we can state that mutations in USH2A are responsible for 76.1% of USH2 disease in patients of Spanish origin.

BRCA1/2 mutation analysis in 41 ovarian cell lines reveals only one functionally deleterious BRCA1 mutation.

LENUS (Irish Health Repository)

Stordal, Britta

2013-06-01

Mutations in BRCA1\\/2 increase the risk of developing breast and ovarian cancer. Germline BRCA1\\/2 mutations occur in 8.6-13.7% of unselected epithelial ovarian cancers, somatic mutations are also frequent. BRCA1\\/2 mutated or dysfunctional cells may be sensitive to PARP inhibition by synthetic lethality. The aim of this study is to comprehensively characterise the BRCA1\\/2 status of a large panel of ovarian cancer cell lines available to the research community to assist in biomarker studies of novel drugs and in particular of PARP inhibitors. The BRCA1\\/2 genes were sequenced in 41 ovarian cell lines, mRNA expression of BRCA1\\/2 and gene methylation status of BRCA1 was also examined. The cytotoxicity of PARP inhibitors olaparib and veliparib was examined in 20 cell lines. The cell line SNU-251 has a deleterious BRCA1 mutation at 5564G > A, and is the only deleterious BRCA1\\/2 mutant in the panel. Two cell lines (UPN-251 and PEO1) had deleterious mutations as well as additional reversion mutations that restored the protein functionality. Heterozygous mutations in BRCA1\\/2 were relatively common, found in 14.6% of cell lines. BRCA1 was methylated in two cell lines (OVCAR8, A1847) and there was a corresponding decrease in gene expression. The BRCA1 methylated cell lines were more sensitive to PARP inhibition than wild-type cells. The SNU-251 deleterious mutant was more sensitive to PARP inhibition, but only in a long-term exposure to correct for its slow growth rate. Cell lines derived from metastatic disease are significantly more resistant to veliparib (2.0 fold p = 0.03) compared to those derived from primary tumours. Resistance to olaparib and veliparib was correlated Pearsons-R 0.5393, p = 0.0311. The incidence of BRCA1\\/2 deleterious mutations 1\\/41 cell lines derived from 33 different patients (3.0%) is much lower than the population incidence. The reversion mutations and high frequency of heterozygous mutations suggest that there is a selective

Use of λgt11 to isolate genes for two pseudorabies virus glycoproteins with homology to herpes simplex virus and varicella-zoster virus glycoproteins

International Nuclear Information System (INIS)

Petrovskis, E.A.; Timmins, J.G.; Post, L.E.

1986-01-01

A library of pseudorabies virus (PRV) DNA fragments was constructed in the expression cloning vector λgt11. The library was screened with antisera which reacted with mixtures of PRV proteins to isolate recombinant bacteriophages expressing PRV proteins. By the nature of the λgt11 vector, the cloned proteins were expressed in Escherichia coli as β-galactosidase fusion proteins. The fusion proteins from 35 of these phages were purified and injected into mice to raise antisera. The antisera were screened by several different assays, including immunoprecipitation of [ 14 C]glucosamine-labeled PRV proteins. This method identified phages expressing three different PRV glycoproteins: the secreted glycoprotein, gX; gI; and a glycoprotein that had not been previously identified, which we designate gp63. The gp63 and gI genes map adjacent to each other in the small unique region of the PRV genome. The DNA sequence was determined for the region of the genome encoding gp63 and gI. It was found that gp63 has a region of homology with a herpes simplex virus type 1 (HSV-1) protein, encoded by US7, and also with varicella-zoster virus (VZV) gpIV. The gI protein sequence has a region of homology with HSV-1 gE and VZV gpI. It is concluded that PRV, HSV, and VZV all have a cluster of homologous glycoprotein genes in the small unique components of their genomes and that the organization of these genes is conserved

BRCA2 Mutations in 154 Finnish Male Breast Cancer Patients

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Kirsi Syrjäkoski

2004-09-01

Full Text Available The etiology and pathogenesis of male breast cancer (MBC are poorly known. This is due to the fact that the disease is rare, and large-scale genetic epidemiologic studies have been difficult to carry out. Here, we studied the frequency of eight recurrent Finnish BRCA2 founder mutations in a large cohort of 154 MBC patients (65% diagnosed in Finland from 1967 to 1996. Founder mutations were detected in 10 patients (6.5%, eight of whom carried the 9346(-2 A>G mutation. Two novel mutations (4075 delGT and 5808 del5 were discovered in a screening of the entire BRCA2 coding region in 34 samples. However, these mutations were not found in the rest of the 120 patients studied. Patients with positive family history of breast and/or ovarian cancer were often BRCA2 mutation carriers (44%, whereas those with no family history showed a low frequency of involvement (3.6%; P < .0001. Finally, we found only one Finnish MBC patient with 999 dell, the most common founder mutation in Finnish female breast cancer (FBC patients, and one that explains most of the hereditary FBC and MBC cases in Iceland. The variation in BRCA2 mutation spectrum between Finnish MBC patients and FBC patients in Finland and breast cancer patients in Iceland suggests that modifying genetic and environmental factors may significantly influence the penetrance of MBC and FBC in individuals carrying germline BRCA2 mutations in some populations.

Human monoclonal antibodies to a novel cluster of conformational epitopes on HCV E2 with resistance to neutralization escape in a genotype 2a isolate

DEFF Research Database (Denmark)

Keck, Zhen-yong; Xia, Jinming; Wang, Yong

2012-01-01

The majority of broadly neutralizing antibodies to hepatitis C virus (HCV) are against conformational epitopes on the E2 glycoprotein. Many of them recognize overlapping epitopes in a cluster, designated as antigenic domain B, that contains residues G530 and D535. To gain information on other reg...

Orthobunyavirus ultrastructure and the curious tripodal glycoprotein spike.

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Thomas A Bowden

Full Text Available The genus Orthobunyavirus within the family Bunyaviridae constitutes an expanding group of emerging viruses, which threaten human and animal health. Despite the medical importance, little is known about orthobunyavirus structure, a prerequisite for understanding virus assembly and entry. Here, using electron cryo-tomography, we report the ultrastructure of Bunyamwera virus, the prototypic member of this genus. Whilst Bunyamwera virions are pleomorphic in shape, they display a locally ordered lattice of glycoprotein spikes. Each spike protrudes 18 nm from the viral membrane and becomes disordered upon introduction to an acidic environment. Using sub-tomogram averaging, we derived a three-dimensional model of the trimeric pre-fusion glycoprotein spike to 3-nm resolution. The glycoprotein spike consists mainly of the putative class-II fusion glycoprotein and exhibits a unique tripod-like arrangement. Protein-protein contacts between neighbouring spikes occur at membrane-proximal regions and intra-spike contacts at membrane-distal regions. This trimeric assembly deviates from previously observed fusion glycoprotein arrangements, suggesting a greater than anticipated repertoire of viral fusion glycoprotein oligomerization. Our study provides evidence of a pH-dependent conformational change that occurs during orthobunyaviral entry into host cells and a blueprint for the structure of this group of emerging pathogens.

Structural and functional analysis of bovine herpesvirus 1 minor glycoproteins

NARCIS (Netherlands)

Baranowski, E.; Keil, G.; Lyaku, J.; Rijsewijk, F.A.M.; Oirschot, van J.T.; Pastoret, P.P.; Thiry, E.

1996-01-01

This paper focuses on the structure and functions of bovine herpesvirus 1 minor glycoproteins gH, gE, gG and gp42. It reviews the progress which has been made in their identification and characterization, in the study of their temporal expression and processing in infected cells, and finally in the

Purification and characterization of a soluble glycoprotein from garlic (Allium sativum) and its in vitro bioactivity.

Science.gov (United States)

Wang, Yan; Zou, Tingting; Xiang, Minghui; Jin, Chenzhong; Zhang, Xuejiao; Chen, Yong; Jiang, Qiuqing; Hu, Yihong

2016-10-02

A soluble glycoprotein was purified to homogeneity from ripe garlic (Allium sativum) bulbs using ammonium sulfate precipitation, Sephadex G-100 gel filtration, and diethylaminoethyl-52 cellulose anion-exchange chromatography. A native mass of 55.7 kDa estimated on gel permeation chromatography and a molecular weight of 13.2 kDa observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis supported that the glycoprotein is a homotetramer. β-Elimination reaction result suggested that the glycoprotein is an N-linked type. Fourier-transform infrared spectroscopy proved that it contains sugar. Gas chromatography-mass spectrometer analysis showed that its sugar component was galactose. The glycoprotein has 1,1-diphenyl-2-picrylhydrazil free radical scavenging activity and the peroxidation inhibition ability to polyunsaturated fatty acid. These results indicated that the glycoprotein has potential for food additives, functional foods, and even biotechnological and medical applications.

Co-treatment by docetaxel and vinblastine breaks down P-glycoprotein mediated chemo-resistance

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Mahsa Mohseni

2016-03-01

Results: Combination treatment of the cells with docetaxel and vinblastine decreased the IC50 values for docetaxel from (30±3.1 to (15±2.6 nM and for vinblastine from (30±5.9 to (5±5.6 nM (P≤0.05.               P-glycoprotein mRNA expression level showed a significant up-regulation in the cells incubated with each drug alone (P≤0.001. Incubation of the cells with combined concentrations of both agents neutralized P-glycoprotein overexpression (P≤0.05. Adding verapamil, a P-glycoprotein inhibitor caused a further increase in the percentage of apoptotic cells when the cells were treated with both agents.  Conclusion:Our results suggest that combination therapy along with P-glycoprotein inhibition can be considered as a novel approach to improve the efficacy of chemotherapeutics in cancer patients with high P-glycoprotein expression.

Frontotemporal dementia caused by CHMP2B mutations

DEFF Research Database (Denmark)

Isaacs, A M; Johannsen, P; Holm, I

2011-01-01

CHMP2B mutations are a rare cause of autosomal dominant frontotemporal dementia (FTD). The best studied example is frontotemporal dementia linked to chromosome 3 (FTD-3) which occurs in a large Danish family, with a further CHMP2B mutation identified in an unrelated Belgian familial FTD patient. ...

JAK2 Exon 12 Mutations in Polycythemia Vera and Idiopathic Erythrocytosis

Science.gov (United States)

Scott, Linda M.; Tong, Wei; Levine, Ross L.; Scott, Mike A.; Beer, Philip A.; Stratton, Michael R.; Futreal, P. Andrew; Erber, Wendy N.; McMullin, Mary Frances; Harrison, Claire N.; Warren, Alan J.; Gilliland, D. Gary; Lodish, Harvey F.; Green, Anthony R.

2010-01-01

BACKGROUND The V617F mutation, which causes the substitution of phenylalanine for valine at position 617 of the Janus kinase (JAK) 2 gene (JAK2), is often present in patients with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. However, the molecular basis of these myeloproliferative disorders in patients without the V617F mutation is unclear. METHODS We searched for new mutations in members of the JAK and signal transducer and activator of transcription (STAT) gene families in patients with V617F-negative polycythemia vera or idiopathic erythrocytosis. The mutations were characterized biochemically and in a murine model of bone marrow transplantation. RESULTS We identified four somatic gain-of-function mutations affecting JAK2 exon 12 in 10 V617F-negative patients. Those with a JAK2 exon 12 mutation presented with an isolated erythrocytosis and distinctive bone marrow morphology, and several also had reduced serum erythropoietin levels. Erythroid colonies could be grown from their blood samples in the absence of exogenous erythropoietin. All such erythroid colonies were heterozygous for the mutation, whereas colonies homozygous for the mutation occur in most patients with V617F-positive polycythemia vera. BaF3 cells expressing the murine erythropoietin receptor and also carrying exon 12 mutations could proliferate without added interleukin-3. They also exhibited increased phosphorylation of JAK2 and extracellular regulated kinase 1 and 2, as compared with cells transduced by wild-type JAK2 or V617F JAK2. Three of the exon 12 mutations included a substitution of leucine for lysine at position 539 of JAK2. This mutation resulted in a myeloproliferative phenotype, including erythrocytosis, in a murine model of retroviral bone marrow transplantation. CONCLUSIONS JAK2 exon 12 mutations define a distinctive myeloproliferative syndrome that affects patients who currently receive a diagnosis of polycythemia vera or idiopathic erythrocytosis

Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations

OpenAIRE

Szpurka, Hadrian; Jankowska, Anna M.; Makishima, Hideki; Bodo, Juraj; Bejanyan, Nelli; Hsi, Eric D.; Sekeres, Mikkael A.; Maciejewski, Jaroslaw P.

2010-01-01

While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation ...

The glycoproteins of Marburg and Ebola virus and their potential roles in pathogenesis.

Science.gov (United States)

Feldmann, H; Volchkov, V E; Volchkova, V A; Klenk, H D

1999-01-01

Filoviruses cause systemic infections that can lead to severe hemorrhagic fever in human and non-human primates. The primary target of the virus appears to be the mononuclear phagocytic system. As the virus spreads through the organism, the spectrum of target cells increases to include endothelial cells, fibroblasts, hepatocytes, and many other cells. There is evidence that the filovirus glycoprotein plays an important role in cell tropism, spread of infection, and pathogenicity. Biosynthesis of the glycoprotein forming the spikes on the virion surface involves cleavage by the host cell protease furin into two disulfide linked subunits GP1 and GP2. GP1 is also shed in soluble form from infected cells. Different strains of Ebola virus show variations in the cleavability of the glycoprotein, that may account for differences in pathogenicity, as has been observed with influenza viruses and paramyxoviruses. Expression of the spike glycoprotein of Ebola virus, but not of Marburg virus, requires transcriptional editing. Unedited GP mRNA yields the nonstructural glycoprotein sGP, which is secreted extensively from infected cells. Whether the soluble glycoproteins GP1 and sGP interfere with the humoral immune response and other defense mechanisms remains to be determined.

The glycoprotein of measles virus

International Nuclear Information System (INIS)

Anttonen, O.; Jokinen, M.; Salmi, A.; Vainionpaeae, R.; Gahmberg, C.G.

1980-01-01

Measles virus was propagated in VERO cells and purified from the culture supernatants by two successive tartrate-density-gradient centrifugations. Surface carbohydrates were labelled both in vitro and in vivo with 3 H after treatment with galactose oxidase/NaB 3 H 4 or with [ 3 H]glucosamine. The major labelled glycoprotein in measles virions had a mol.wt. of 79000. After labelling with periodate/NaB 3 H 4 , which would result in specific labelling of sialic acid residues, the 79000-mol.wt. glycoprotein was very weakly labelled. This suggested that there is no or a very low amount of sialic acid in the virions. Further analysis of the glycoprotein showed that galactose is the terminal carbohydrate unit in the oligosaccharide, and the molecular weight of the glycopeptide obtained after Pronase digestion is about 3000. The oligosaccharide is attached to the polypeptide through an alkali-stable bond, indicating a N-glycosidic asparagine linkage. (author)

Identification of four novel mutations of the WFS1 gene in Iranian Wolfram syndrome pedigrees.

Science.gov (United States)

Ghahraman, Martha; Abbaszadegan, Mohammad Reza; Vakili, Rahim; Hosseini, Sousan; Fardi Golyan, Fatemeh; Ghaemi, Nosrat; Forghanifard, Mohammad Mahdi

2016-12-01

Wolfram syndrome is a rare neurodegenerative disorder with an autosomal recessive pattern of inheritance characterized by various clinical manifestations. The related gene, WFS1, encodes a transmembrane glycoprotein, named wolframin. Genetic analyses demonstrated that mutations in this gene are associated with WS type 1. Our aim in this study was to sequence WFS1 coding region in Iranian Wolfram syndrome pedigrees. Genomic DNA was extracted from peripheral blood of 12 WS patients and their healthy parents. Exons 2-8 and the exon-intron junctions of WFS1 were sequenced. DNA sequences were compared to the reference using Sequencher software. Molecular analysis of WFS1 revealed six different mutations. Four novel and two previously reported mutations were identified. One novel mutation, c.1379_1381del, is predicted to produce an aberrant protein. A second novel mutation, c.1384G > T, encodes a truncated protein. Novel mutation, c.1097-1107dup (11 bp), causes a frameshift which results in a premature stop codon. We screened for the novel missense mutation, c.1010C > T, in 100 control alleles. This mutation was not found in any of the healthy controls. Our study increased the spectrum of WFS1 mutations and supported the role of WFS1 in susceptibility to WS. We hope that these findings open new horizons to future molecular investigations which may help to prevent and treat this devastating disease.

Distribution of human papilloma virus type 16 E6/E7 gene mutation in cervical precancer or cancer: A case control study in Guizhou Province, China.

Science.gov (United States)

Yang, Yingjie; Ren, Jie; Zhang, Qizhu

2016-02-01

HPV-16 varies geographically and is correlated with cervical cancer genesis and progression. This study aimed to determine the distribution of HPV-16 E6/E7 genetic variation in patients with invasive cervical cancer or precancer in Guizhou Province, China. A case-control study was designed, and the distribution of HPV-16 E6/E7 genetic variation was compared among women with cervical cancer, precancer, and sexually active without cervical lesion. HPV infection was detected through flow-through hybridization and gene chip techniques to determine the prevalence of HPV 16 E6/E7 genetic variation. Among 90 specimens (30 cervical cancer, 30 precancer, 30 controls), 81 were subjected to HPV-16 E6/E7 gene sequencing. The rates of DNA sequence mutation and amino acid mutation were 76.5% (62/81) and 66.7% (54/81), respectively. Both E6 and E7 genes showed higher mutation rate than their prototypes. The prevalence of E6/E7 mutation significantly differed between the cervical cancer and the controls (P prevalent in cervical cancer or precancer than those in the controls. The possible correlation between genetic variation and cancerigenesis may be used to design an HPV vaccine for cervical carcinoma. © 2015 Wiley Periodicals, Inc.

SDHAF2 mutations in familial and sporadic paraganglioma and phaeochromocytoma.

NARCIS (Netherlands)

Bayley, J.P.M.; Kunst, H.P.M.; Cascon, A.; Sampietro, M.L.; Gaal, J.; Korpershoek, E.; Hinojar-Gutierrez, A.; Timmers, H.J.L.M.; Hoefsloot, L.H.; Hermsen, M.A.; Suarez, C.; Hussain, A.K.; Vriends, A.H.; Hes, F.J.; Jansen, J.C.; Tops, C.M.; Corssmit, E.P.; Knijff, P. de; Lenders, J.W.M.; Cremers, C.W.R.J.; Devilee, P.; Dinjens, W.N.; Krijger, R.R. de; Robledo, M.

2010-01-01

BACKGROUND: Paragangliomas and phaeochromocytomas are neuroendocrine tumours associated frequently with germline mutations of SDHD, SDHC, and SDHB. Previous studies have shown the imprinted SDHAF2 gene to be mutated in a large Dutch kindred with paragangliomas. We aimed to identify SDHAF2 mutation

Mucus glycoprotein secretion by tracheal explants: effects of pollutants

International Nuclear Information System (INIS)

Last, J.A.; Kaizu, T.

1980-01-01

Tracheal slices incubated with radioactive precursors in tissue culture medium secrete labeled mucus glycoproteins into the culture medium. We have used an in vivtro approach, a combined method utilizing exposure to pneumotoxins in vivo coupled with quantitation of mucus secretion rates in vitro, to study the effects of inhaled pollutants on mucus biosynthesis by rat airways. In addition, we have purified the mucus glycoproteins secreted by rat tracheal explants in order to determine putative structural changes that might by the basis for the observed augmented secretion rates after exposure of rats to H2SO4 aerosols in combination with high ambient levels of ozone. After digestion with papain, mucus glycoproteins secreted by tracheal explants may be separated into five fractions by ion-exchange chromatography, with recovery in high yield, on columns of DEAE-cellulose. Each of these five fractions, one neutral and four acidic, migrates as a single unique spot upon cellulose acetate electrophoresis at pH values of 8.6 and 1.2. The neutral fraction, which is labeled with [3H] glucosamine, does not contain radioactivity when Na2 35SO4 is used as the precursor. Acidic fractions I to IV are all labeled with either 3H-glucosamine or Na2 35SO4 as precursor. Acidic fraction II contains sialic acid as the terminal sugar on its oligosaccharide side chains, based upon its chromatographic behavior on columns of wheat-germ agglutinin-Agarose. Treatment of this fraction with neuraminidase shifts its elution position in the gradient to a lower salt concentration, coincident with acidic fraction I. After removal of terminal sialic acid residues with either neuraminidase or low pH treatment, the resultant terminal sugar on the oligosaccharide side chains is fucose. These results are identical with those observed with mucus glycoproteins secreted by cultured human tracheal explants and purified by these same techniques

[Connexin gene 26 (GJB2) mutations in patients with hereditary non-syndromic sensorineural loss of hearing in the Republic of Sakha (Yakutia)].

Science.gov (United States)

Barashkov, N A; Dzhemileva, L U; Fedorova, S A; Maksimova, N R; Khusnutdinova, E K

2008-01-01

The aim of the study was to elucidate the causes of hereditary non-syndromic loss of hearing, a frequent monogene pathology in the Republic of Sakha (Yakutia). A search for mutations in the coding sequence of the connexin 26 gene gap-junction B2 (GJB2) was undertaken in 79 members of 65 unrelated families with the diagnosis of grade III-IV non-syndromic bilateral sensorineural loss of hearing. Five recessive mutations (35delG, V371, 312-326del14, 333-334delAA, R127H) and three polymorphic variants (V271, M34T, E114G) were identified in Yakut patients. Mutations 35delG (41.7%), 312-326dell4 (4.2%), and 333-334delAA (4.2%) were found in Caucasian patients (Russians, Ukrainians, Inguish). Yakuts were carriers of mutations 35delG (2.1%), V371 (2.1%), R127H (1.0%) and sequence variants V271 (6.3%), M34T (1.0%), E114G (1.0%). GJB2 mutations were identified in 50.1% of the Caucasian patients and in 7.2% of the Yakut patients. The low frequency of GJB2 mutations in Yakuts with non-syndromic sensorineural loss of hearing testifies to the presence of mutations of other genes controlling sound perception in this population.

The clinical phenotype of Lynch syndrome due to germline PMS2 mutations

Science.gov (United States)

Senter, Leigha; Clendenning, Mark; Sotamaa, Kaisa; Hampel, Heather; Green, Jane; Potter, John D.; Lindblom, Annika; Lagerstedt, Kristina; Thibodeau, Stephen N.; Lindor, Noralane M.; Young, Joanne; Winship, Ingrid; Dowty, James G.; White, Darren M.; Hopper, John L.; Baglietto, Laura; Jenkins, Mark A.; de la Chapelle, Albert

2009-01-01

Background and Aims Although the clinical phenotype of Lynch syndrome (also known as Hereditary Nonpolyposis Colorectal Cancer) has been well described, little is known about disease in PMS2 mutation carriers. Now that mutation detection methods can discern mutations in PMS2 from mutations in its pseudogenes, more mutation carriers have been identified. Information about the clinical significance of PMS2 mutations is crucial for appropriate counseling. Here, we report the clinical characteristics of a large series of PMS2 mutation carriers. Methods We performed PMS2 mutation analysis using long range PCR and MLPA for 99 probands diagnosed with Lynch syndrome-associated tumors showing isolated loss of PMS2 by immunohistochemistry. Penetrance was calculated using a modified segregation analysis adjusting for ascertainment. Results Germline PMS2 mutations were detected in 62% of probands (n = 55 monoallelic; 6 biallelic). Among families with monoallelic PMS2 mutations, 65.5% met revised Bethesda guidelines. Compared with the general population, in mutation carriers, the incidence of colorectal cancer was 5.2 fold higher and the incidence of endometrial cancer was 7.5 fold higher. In North America, this translates to a cumulative cancer risk to age 70 of 15–20% for colorectal cancer, 15% for endometrial cancer, and 25–32% for any Lynch syndrome-associated cancer. No elevated risk for non-Lynch syndrome-associated cancers was observed. Conclusions PMS2 mutations contribute significantly to Lynch syndrome but the penetrance for monoallelic mutation carriers appears to be lower than that for the other mismatch repair genes. Modified counseling and cancer surveillance guidelines for PMS2 mutation carriers are proposed. PMID:18602922

Glycan structures contain information for the spatial arrangement of glycoproteins in the plasma membrane.

Directory of Open Access Journals (Sweden)

M Kristen Hall

Full Text Available Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro(-5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells.

Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junin arenavirus envelope glycoprotein

International Nuclear Information System (INIS)

York, Joanne; Agnihothram, Sudhakar S.; Romanowski, Victor; Nunberg, Jack H.

2005-01-01

The G2 fusion subunit of the Junin virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever

MSH6 and PMS2 mutation positive Australian Lynch syndrome families: novel mutations, cancer risk and age of diagnosis of colorectal cancer.

Science.gov (United States)

Talseth-Palmer, Bente A; McPhillips, Mary; Groombridge, Claire; Spigelman, Allan; Scott, Rodney J

2010-05-21

Approximately 10% of Lynch syndrome families have a mutation in MSH6 and fewer families have a mutation in PMS2. It is assumed that the cancer incidence is the same in families with mutations in MSH6 as in families with mutations in MLH1/MSH2 but that the disease tends to occur later in life, little is known about families with PMS2 mutations. This study reports on our findings on mutation type, cancer risk and age of diagnosis in MSH6 and PMS2 families. A total of 78 participants (from 29 families) with a mutation in MSH6 and 7 participants (from 6 families) with a mutation in PMS2 were included in the current study. A database of de-identified patient information was analysed to extract all relevant information such as mutation type, cancer incidence, age of diagnosis and cancer type in this Lynch syndrome cohort. Cumulative lifetime risk was calculated utilising Kaplan-Meier survival analysis. MSH6 and PMS2 mutations represent 10.3% and 1.9%, respectively, of the pathogenic mutations in our Australian Lynch syndrome families. We identified 26 different MSH6 and 4 different PMS2 mutations in the 35 families studied. We report 15 novel MSH6 and 1 novel PMS2 mutations. The estimated cumulative risk of CRC at age 70 years was 61% (similar in males and females) and 65% for endometrial cancer in MSH6 mutation carriers. The risk of developing CRC is different between males and females at age 50 years, which is 34% for males and 21% for females. Novel MSH6 and PMS2 mutations are being reported and submitted to the current databases for identified Lynch syndrome mutations. Our data provides additional information to add to the genotype-phenotype spectrum for both MSH6 and PMS2 mutations.

Analysis of alkaptonuria (AKU) mutations and polymorphisms reveals that the CCC sequence motif is a mutational hot spot in the homogentisate 1,2 dioxygenase gene (HGO).

Science.gov (United States)

Beltrán-Valero de Bernabé, D; Jimenez, F J; Aquaron, R; Rodríguez de Córdoba, S

1999-01-01

We recently showed that alkaptonuria (AKU) is caused by loss-of-function mutations in the homogentisate 1,2 dioxygenase gene (HGO). Herein we describe haplotype and mutational analyses of HGO in seven new AKU pedigrees. These analyses identified two novel single-nucleotide polymorphisms (INV4+31A-->G and INV11+18A-->G) and six novel AKU mutations (INV1-1G-->A, W60G, Y62C, A122D, P230T, and D291E), which further illustrates the remarkable allelic heterogeneity found in AKU. Reexamination of all 29 mutations and polymorphisms thus far described in HGO shows that these nucleotide changes are not randomly distributed; the CCC sequence motif and its inverted complement, GGG, are preferentially mutated. These analyses also demonstrated that the nucleotide substitutions in HGO do not involve CpG dinucleotides, which illustrates important differences between HGO and other genes for the occurrence of mutation at specific short-sequence motifs. Because the CCC sequence motifs comprise a significant proportion (34.5%) of all mutated bases that have been observed in HGO, we conclude that the CCC triplet is a mutational hot spot in HGO. PMID:10205262

Inactivating Mutation screening of Exon 6 and Exon 10E of FSHR gene in women with Polycystic Ovarian Syndrome in Vellore population

Science.gov (United States)

Sekar, Nishu; Sapre, Madhura; Kale, Vaikhari; Prabhu, Yogamaya D.; Renu, Kaviyarasi; Ramgir, Shalaka S.; Abilash, V. G.

2017-11-01

Polycystic Ovarian syndrome (PCOS) is a major cause of infertility in females of reproducing age and is typified by oligo-anovulation, hyperandrogenism, hirsutism and polycystic ovaries. FSHR gene located on chromosome 2 p21 is responsible for the normal follicular development and any deletion or mutation in the gene affects the interaction of FSH with its receptor. Thus, it becomes the candidate gene for PCOS study. Inactivating mutation in FSHR gene limits the receptor’s function by creating a complete block, changing the receptor-ligand complex or the basic hormone signal transduction.To screen the inactivating mutations in Exon 6 and Exon 10E of FSHR gene in women diagnosed with PCOS.PCR-RFLP analysis indicated that there were no inactivating mutations found in Exon 6 and Exon 10E. Variations in hormone levels were seen amongst the PCOS patients. There were no inactivating mutations found in FSHR gene of the women diagnosed with PCOS according to the Rotterdam criteria in Vellore population.

Mutations in galactosemia

Energy Technology Data Exchange (ETDEWEB)

Reichardt, J.K.V. [Univ. of Southern California School of Medicine, Los Angeles, CA (United States)

1995-10-01

This Letter raises four issues concerning two papers on galactosemia published in the March 1995 of the Journal. First, table 2 in the paper by Elsas et al. incorrectly attributes seven galactose-l-phosphate uridyl transferase (GALT) mutations (S135L, L195P, K285N, N314D, R333W, R333G, and K334R). The table also fails to mention that others have reported the same two findings attributed to {open_quotes}Leslie et al.; Elsas et al. and in press{close_quotes} and {open_quotes}Leslie et al.; Elsas et al.{close_quotes} The first finding on the prevalence of the Q188R galactosemia mutation in the G/G Caucasian population has also been described by Ng et al., and the second finding on the correlation of the N314D GALT mutation with the Duarte variant was reported by Lin et al. Second, Elsas et al. suggest that the E203K and N314D mutations may {open_quotes}produce intra-allelic complementation when in cis{close_quotes}. This speculation is supported by the activity data of individual III-2 but is inconsistent with the activities of three other individuals I-1, II-1, and III-1 of the same pedigree. The GALT activity measured in these three individuals suggests a dominant negative effect of E203K in E203K-N314D chromosomes, since they all have less than normal activity. Thus, the preponderance of the data in this paper is at odds with the authors speculation. It is worth recalling that Lin et al. also identified four N314D GALT mutations on 95 galactosemic chromosomes examined. A similar situation also appears to be the case in proband III-1 (with genotype E203K-N314D/IVSC) in the Elsas et al. paper. 9 refs.

Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Bryony Jenkins

2016-12-01

Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

Novel USH2A mutations in Israeli patients with retinitis pigmentosa and Usher syndrome type 2.

Science.gov (United States)

Kaiserman, Nadia; Obolensky, Alexey; Banin, Eyal; Sharon, Dror

2007-02-01

To identify USH2A mutations in Israeli patients with autosomal-recessive Usher syndrome type 2 (USH2) and retinitis pigmentosa (RP). Patients from 95 families with RP and 4 with USH2 were clinically evaluated. USH2A exons 2-72 were scanned for mutations using single-strand conformation and sequencing analyses. The frequency of novel missense changes was determined in patients and controls using restriction endonucleases. The analysis revealed 3 USH2A mutations, 2 of which are novel, in 2 families with USH2 and a large family (MOL0051) with both USH2 and RP. Compound heterozygotes for 2 null mutations (Thr80fs and Arg737stop) in MOL0051 suffered from USH2 while compound heterozygotes for 1 of the null mutations and a novel missense mutation (Gly4674Arg) had nonsyndromic RP. Our results support the involvement of USH2A in nonsyndromic RP and we report here of a second, novel, missense mutation in this gene causing autosomal-recessive RP. Possible involvement of USH2A should be considered in the molecular genetic evaluation of patients with autosomal-recessive RP. Understanding the mechanism by which different USH2A mutations cause either USH2 or RP may assist in the development of novel therapeutic approaches.

Mutations in the HFE, TFR2, and SLC40A1 genes in patients with hemochromatosis.

Science.gov (United States)

Del-Castillo-Rueda, Alejandro; Moreno-Carralero, María-Isabel; Cuadrado-Grande, Nuria; Alvarez-Sala-Walther, Luis-Antonio; Enríquez-de-Salamanca, Rafael; Méndez, Manuel; Morán-Jiménez, María-Josefa

2012-10-15

Hereditary hemochromatosis causes iron overload and is associated with a variety of genetic and phenotypic conditions. Early diagnosis is important so that effective treatment can be administered and the risk of tissue damage avoided. Most patients are homozygous for the c.845G>A (p.C282Y) mutation in the HFE gene; however, rare forms of genetic iron overload must be diagnosed using a specific genetic analysis. We studied the genotype of 5 patients who had hyperferritinemia and an iron overload phenotype, but not classic mutations in the HFE gene. Two patients were undergoing phlebotomy and had no iron overload, 1 with metabolic syndrome and no phlebotomy had mild iron overload, and 2 patients had severe iron overload despite phlebotomy. The patients' first-degree relatives also underwent the analysis. We found 5 not previously published mutations: c.-408_-406delCAA in HFE, c.1118G>A (p.G373D), c.1473G>A (p.E491E) and c.2085G>C (p.S695S) in TFR2; and c.-428_-427GG>TT in SLC40A1. Moreover, we found 3 previously published mutations: c.221C>T (p.R71X) in HFE; c.1127C>A (p.A376D) in TFR2; and c.539T>C (p.I180T) in SLC40A1. Four patients were double heterozygous or compound heterozygous for the mutations mentioned above, and the patient with metabolic syndrome was heterozygous for a mutation in the TFR2 gene. Our findings show that hereditary hemochromatosis is clinically and genetically heterogeneous and that acquired factors may modify or determine the phenotype. Copyright © 2012. Published by Elsevier B.V.

Wild-type and mutated IDH1/2 enzymes and therapy responses.

Science.gov (United States)

Molenaar, Remco J; Maciejewski, Jaroslaw P; Wilmink, Johanna W; van Noorden, Cornelis J F

2018-04-01

Isocitrate dehydrogenase 1 and 2 (IDH1/2) are key enzymes in cellular metabolism, epigenetic regulation, redox states, and DNA repair. IDH1/2 mutations are causal in the development and/or progression of various types of cancer due to supraphysiological production of D-2-hydroxyglutarate. In various tumor types, IDH1/2-mutated cancers predict for improved responses to treatment with irradiation or chemotherapy. The present review discusses the molecular basis of the sensitivity of IDH1/2-mutated cancers with respect to the function of mutated IDH1/2 in cellular processes and their interactions with novel IDH1/2-mutant inhibitors. Finally, lessons learned from IDH1/2 mutations for future clinical applications in IDH1/2 wild-type cancers are discussed.

Association of two mutations in the CHEK2 gene with breast cancer

International Nuclear Information System (INIS)

Bogdanova, N.; Enben-Dubrowinskaja, N.; Doerk, T.; Feshchenko, S.; Lazyuk, G.I.; Rogov, Yu.I.

2005-01-01

Cell-cycle checkpoint kinase 2 (CHEK2) is a central mediator of cellular responses to DNA damage. Ionizing radiation activates the CHEK2 protein via ATM-mediated phosphorylation and activated CHEK2 kinase can phosphorylate several substrates, including Cdc25A, p53 and E2F1, which mediate cell cycle arrest and apoptosis. CHEK2 phosphorylation of the breast cancer susceptibility protein BRCA1 regulates DNA double-strand break repair, and deletion of CHEK2 potentiate the incidence of mammary carcinomas in BRCA1 conditional mutant mice. A truncating variant of CHEK2, the 1100 delC mutation, has been identified as a low-penetrance breast-cancer susceptibility allele. Heterozygous 1100 delC carriers have an approximately 2-fold increased risk for breast cancer. The role of variants in CHEK2 other than 1100 delC is less clear. To assess the role of these CHEK2 variants in breast cancer, we conducted an association study of the I157T and IVS211G>A mutations in breast cancer case-control settings from the Belarus populations. Our series consisted of 424 breast cancer patients and 307 population controls. The missense substitution I157T was identified in 24/424 cases (5.7%) vs. 4/307 controls (1.3%; OR 54.5, 95% CI 1.6-13.2, p 5 0.005) in investigated cohorts. The splicing mutation IVS211G > A was infrequent, being observed 4/424 patients (0.9%). Heterozygous CHEK2 mutation carriers tended to be diagnosed at an earlier age, but these differences did not reach statistical significance. Family history of breast cancer did not differ between carriers and non carriers. Our data indicate that the I157T allele, and possibly the IVS211G > A allele, of the CHEK2 gene contribute to inherited breast cancer susceptibility. (authors)

An inverted repeat motif stabilizes binding of E2F and enhances transcription of the dihydrofolate reductase gene

DEFF Research Database (Denmark)

Wade, M; Blake, M C; Jambou, R C

1995-01-01

consensus E2F site, significantly decrease the binding stability of all of the forms of E2F tested. The rate of association of E2F-1/DP-1 heterodimers with the inverted repeat wild type site was not significantly different from those with the two single site mutated probes. Furthermore, the mutations...

Neutralizing activities of caprine antibodies towards conserved regions of the HCV envelope glycoprotein E2

Directory of Open Access Journals (Sweden)

El-Shenawy Reem

2011-08-01

Full Text Available Abstract Anti HCV vaccine is not currently available and the present antiviral therapies fail to cure approximately half of the treated HCV patients. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 and test their neutralizing activities in a step towards developing therapeutic and/or prophylactic immunogens against HCV infection. Antibodies were generated by vaccination of goats with synthetic peptides derived from HCV E2. Viral neutralizing capacity of the generated anti E2 antibodies was tested using in vitro assays. Goats immunized with E2 synthetic peptides termed p412 [a.a 412-419], p430 [a.a 430-447] and p517 [a.a 517-531] generated high titers of antibody responses 2 to 4.5 fold higher than comparable titers of antibodies to the same epitopes in chronic HCV patients. In post infection experiments of native HCV into cultured Huh7.5 cells anti p412 and anti p 517 were proven to be neutralizing to HCV genotype 4a from patients' sera (87.5% and 75% respectively. On the contrary anti p430 exhibited weak viral neutralization capacity on the same samples (31.25%. Furthermore Ab mixes containing anti p430 exhibited reduced viral neutralization properties. From these experiments one could predict that neutralization by Abs towards different E2-epitopes varies considerably and success in the enrichment of neutralization epitope-specific antibodies may be accompanied by favorable results in combating HCV infection. Also, E2 conserved peptides p517 and p412 represent potential components of a candidate peptide vaccine against HCV infection.

Darier disease mutation E917K/E918K of SERCA causes accumulation of the E2 form

DEFF Research Database (Denmark)

Mikkelsen, Stine; Holdensen, Anne Nyholm; Vilsen, Bente

2011-01-01

. SERCA2b E917K as well as SERCA1a E918K reduces the apparent Ca2+ affinity 2- to 3-fold, compared with the respective wild type. The resulting disturbance of Ca2+ homeostasis is probably the reason for the abnormalities of epidermal cells in the Darier disease patients. The reduction of apparent Ca2...

BRAF V600E mutations in papillary craniopharyngioma

Science.gov (United States)

Brastianos, Priscilla K.; Santagata, Sandro

2016-01-01

Papillary craniopharyngioma is an intracranial tumor that results in high levels of morbidity. We recently demonstrated that the vast majority of these tumors harbor the oncogenic BRAF V600E mutation. The pathologic diagnosis of papillary craniopharyngioma can now be confirmed using mutation specific immunohistochemistry and targeted genetic testing. Treatment with targeted agents is now also a possibility in select situations. We recently reported a patient with a multiply recurrent papillary craniopharyngioma in whom targeting both BRAF and MEK resulted in a dramatic therapeutic response with a marked anti-tumor immune response. This work shows that activation of the MAPK pathway is the likely principal oncogenic driver of these tumors. We will now investigate the efficacy of this approach in a multicenter phase II clinical trial. Post-treatment resection samples will be monitored for the emergence of resistance mechanisms. Further advances in the non-invasive diagnosis of papillary craniopharyngioma by radiologic criteria and by cell-free DNA testing could someday allow neo-adjuvant therapy for this disease in select patient populations. PMID:26563980

Calreticulin mutation analysis in non-mutated Janus kinase 2 essential thrombocythemia patients in Chiang Mai University: analysis of three methods and clinical correlations.

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Rattarittamrong, Ekarat; Tantiworawit, Adisak; Kumpunya, Noppamas; Wongtagan, Ornkamon; Tongphung, Ratchanoo; Phusua, Arunee; Chai-Adisaksopha, Chatree; Hantrakool, Sasinee; Rattanathammethee, Thanawat; Norasetthada, Lalita; Charoenkwan, Pimlak; Lekawanvijit, Suree

2018-03-09

The primary objective was to determine the prevalence of calreticulin (CALR) mutation in patients with non-JAK2V617F mutated essential thrombocythemia (ET). The secondary objectives were to evaluate the accuracy of CALR mutation analysis by high-resolution melting (HRM) analysis and real-time polymerase chain reaction (PCR) compared with DNA sequencing and to compare clinical characteristics of CALR mutated and JAK2V617F mutated ET. This was a prospective cohort study involving ET patients registered at Chiang Mai University in the period September 2015-September 2017 who were aged more than 2 years, and did not harbor JAK2V617F mutation. The presence of CALR mutation was established by DNA sequencing, HRM, and real-time PCR for type 1 and type 2 mutation. Clinical data were compared with that from ET patients with mutated JAK2V617F. Twenty-eight patients were enrolled onto the study. CALR mutations were found in 10 patients (35.7%). Three patients had type 1 mutation, 5 patients had type 2 mutation, 1 patient had type 18 mutation, and 1 patients had novel mutations (c.1093 C-G, c.1098_1131 del, c.1135 G-A). HRM could differentiate between the types of mutation in complete agreement with DNA sequencing. Patients with a CALR mutation showed a significantly greater male predominance and had a higher platelet count when compared with 42 JAK2V617F patients. The prevalence of CALR mutation in JAK2V617F-negative ET in this study is 35.7%. HRM is an effective method of detecting CALR mutation and is a more advantageous method of screening for CALR mutation.

Parkinson's disease-related LRRK2 G2019S mutation results from independent mutational events in humans.

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Lesage, Suzanne; Patin, Etienne; Condroyer, Christel; Leutenegger, Anne-Louise; Lohmann, Ebba; Giladi, Nir; Bar-Shira, Anat; Belarbi, Soraya; Hecham, Nassima; Pollak, Pierre; Ouvrard-Hernandez, Anne-Marie; Bardien, Soraya; Carr, Jonathan; Benhassine, Traki; Tomiyama, Hiroyuki; Pirkevi, Caroline; Hamadouche, Tarik; Cazeneuve, Cécile; Basak, A Nazli; Hattori, Nobutaka; Dürr, Alexandra; Tazir, Meriem; Orr-Urtreger, Avi; Quintana-Murci, Lluis; Brice, Alexis

2010-05-15

Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (PD) and in sporadic cases; the G2019S mutation is the single most frequent. Intriguingly, the frequency of this mutation in PD patients varies greatly among ethnic groups and geographic origins: it is present at <0.1% in East Asia, approximately 2% in European-descent patients and can reach frequencies of up to 15-40% in PD Ashkenazi Jews and North African Arabs. To ascertain the evolutionary dynamics of the G2019S mutation in different populations, we genotyped 74 markers spanning a 16 Mb genomic region around G2019S, in 191 individuals carrying the mutation from 126 families of different origins. Sixty-seven families were of North-African Arab origin, 18 were of North/Western European descent, 37 were of Jewish origin, mostly from Eastern Europe, one was from Japan, one from Turkey and two were of mixed origins. We found the G2019S mutation on three different haplotypes. Network analyses of the three carrier haplotypes showed that G2019S arose independently at least twice in humans. In addition, the population distribution of the intra-allelic diversity of the most widespread carrier haplotype, together with estimations of the age of G2019S determined by two different methods, suggests that one of the founding G2019S mutational events occurred in the Near East at least 4000 years ago.

Immunoreactive serum opsonic alpha 2 sb glycoprotein as a noninvasive index of RES systemic defense after trauma.

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Kaplan, J E; Saba, T M

1979-01-01

Reticuloendothelial system (RES) depression has been correlated with diminished resistance to trauma, shock, and sepsis in man and animals. Previous studies have related the depression of RES hepatic Kupffer cell phagocytic function after trauma to diminished bioassayable opsonic activity. The present study determined if the loss of biological activity and RES alteration correlated with immunoreactive serum opsonic alpha 2 SB glycoprotein levels after trauma. Serum opsonic activity was measured by liver slice bioassay, and immunoreactive opsonic protein was measured by rocket electroimmunoassay. RE function was determined by colloid clearance over a 24-hour post-trauma period. Anesthetized rats (250-300 gm) subjected to sublethal or severe (greater than LD50) whole-body NCD trauma were the shock models investigated. Immunoreactive levels in 63 rats prior to injury were 518 +/- 24 microgram/ml. Neither biological nor immunoreactive levels were altered over 24 hours in anesthetized sham-traumatized controls. Temporal alteration in the initial decrease and recovery pattern of biologically active and immunoreactive opsonic protein levels significantly correlated following both sublethal and severe injury. Moreover, the patterns of immunoreactive levels of the opsonic protein correlated with the functional phagocytic activity of the RES as determined by vascular clearance of a test dose of blood-borne radiolabeled particulates. This glycoprotein falls after trauma, and the magnitude and duration of the decline increases with severity of injury. Immunoreactive opsonic alpha 2 SB glycoprotein appears to be an accurate measurement of circulating opsonic activity and RE Kupffer cell function after trauma, especially with respect to clearance. Thus, immunoreactive opsonic protein warrants clinical consideration as a noninvasive measure of reticuloendothelial systemic defense in patients after trauma and burn.

Thiolated polymers: evidence for the formation of disulphide bonds with mucus glycoproteins.

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Leitner, Verena M; Walker, Greg F; Bernkop-Schnürch, Andreas

2003-09-01

Disulphide bonds between thiolated polymers (thiomers) and cysteine-rich subdomains of mucus glycoproteins are supposed to be responsible for the enhanced mucoadhesive properties of thiomers. This study set out to provide evidence for these covalent interactions using poly(acrylic acid)-cysteine conjugates of 2 and 450 kDa (PAA2-Cys, PAA450-Cys) displaying 402.5-776.0 micromol thiol groups per gram polymer. The effect of the disulphide bond breaker cysteine on thiomer-mucin disulphide bonds was monitored by (1) mucoadhesion studies and (2) rheological studies. Furthermore, (3) diffusion studies and (4) gel filtration studies were performed with thiomer-mucus mixtures. The addition of cysteine significantly (Ppolymer. Gel filtration studies showed that PAA2-Cys was able to form disulphide bonds with mucin glycoproteins resulting in an altered elution profile of the mucin/PAA2-Cys mixture in comparison to mucin alone or mucin/PAA2 mixture. According to these results, the study provides evidence for the formation of covalent bonds between thiomer and mucus glycoproteins.

LRIG2 mutations cause urofacial syndrome.

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Stuart, Helen M; Roberts, Neil A; Burgu, Berk; Daly, Sarah B; Urquhart, Jill E; Bhaskar, Sanjeev; Dickerson, Jonathan E; Mermerkaya, Murat; Silay, Mesrur Selcuk; Lewis, Malcolm A; Olondriz, M Beatriz Orive; Gener, Blanca; Beetz, Christian; Varga, Rita E; Gülpınar, Omer; Süer, Evren; Soygür, Tarkan; Ozçakar, Zeynep B; Yalçınkaya, Fatoş; Kavaz, Aslı; Bulum, Burcu; Gücük, Adnan; Yue, Wyatt W; Erdogan, Firat; Berry, Andrew; Hanley, Neil A; McKenzie, Edward A; Hilton, Emma N; Woolf, Adrian S; Newman, William G

2013-02-07

Urofacial syndrome (UFS) (or Ochoa syndrome) is an autosomal-recessive disease characterized by congenital urinary bladder dysfunction, associated with a significant risk of kidney failure, and an abnormal facial expression upon smiling, laughing, and crying. We report that a subset of UFS-affected individuals have biallelic mutations in LRIG2, encoding leucine-rich repeats and immunoglobulin-like domains 2, a protein implicated in neural cell signaling and tumorigenesis. Importantly, we have demonstrated that rare variants in LRIG2 might be relevant to nonsyndromic bladder disease. We have previously shown that UFS is also caused by mutations in HPSE2, encoding heparanase-2. LRIG2 and heparanase-2 were immunodetected in nerve fascicles growing between muscle bundles within the human fetal bladder, directly implicating both molecules in neural development in the lower urinary tract. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Relationship between recurrent spontaneous abortion and anti-β2-glycoprotein I antibody

International Nuclear Information System (INIS)

Liu Jingzhu; Hu Jing; Zhang Shiping; Zhang Shuang; Lin Li; Fan Jing

2008-01-01

Objective: To explore the relationship between recurrent spontaneous abortion (RSA) and anti-β 2 - glycoprotein I (anti-β 2 -GP I) antibody. Methods: The levels of anti-β 2 -GP I antibody in serum from 81 RSA patients and 39 normal women were detected by ELISA. Results: The positive rate of anti-β 2 -GP I in RSA patients (42.0%) was obviously higher than that in normal women (7.7 %) (P 2 -GP I IgG in statistics between RSA patients (40.8%) and normal women (7.7%) (P 2 -GP I IgM in statistics between RSA patients and normal women (P>0.05). There was no difference of the positive rate of anti-β 2 -GP I in statistics between early and late, as well as between 2 times and more than 2 times abortions of RSA (P>0.05). Conclusion: The anti-β 2 -GP I antibody is related to RSA, and it may be regarded as a immunological assistant diagnostic index for RSA. (authors)

MSH6 and PMS2 mutation positive Australian Lynch syndrome families: novel mutations, cancer risk and age of diagnosis of colorectal cancer

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Talseth-Palmer Bente A

2010-05-01

Full Text Available Abstract Background Approximately 10% of Lynch syndrome families have a mutation in MSH6 and fewer families have a mutation in PMS2. It is assumed that the cancer incidence is the same in families with mutations in MSH6 as in families with mutations in MLH1/MSH2 but that the disease tends to occur later in life, little is known about families with PMS2 mutations. This study reports on our findings on mutation type, cancer risk and age of diagnosis in MSH6 and PMS2 families. Methods A total of 78 participants (from 29 families with a mutation in MSH6 and 7 participants (from 6 families with a mutation in PMS2 were included in the current study. A database of de-identified patient information was analysed to extract all relevant information such as mutation type, cancer incidence, age of diagnosis and cancer type in this Lynch syndrome cohort. Cumulative lifetime risk was calculated utilising Kaplan-Meier survival analysis. Results MSH6 and PMS2 mutations represent 10.3% and 1.9%, respectively, of the pathogenic mutations in our Australian Lynch syndrome families. We identified 26 different MSH6 and 4 different PMS2 mutations in the 35 families studied. We report 15 novel MSH6 and 1 novel PMS2 mutations. The estimated cumulative risk of CRC at age 70 years was 61% (similar in males and females and 65% for endometrial cancer in MSH6 mutation carriers. The risk of developing CRC is different between males and females at age 50 years, which is 34% for males and 21% for females. Conclusion Novel MSH6 and PMS2 mutations are being reported and submitted to the current databases for identified Lynch syndrome mutations. Our data provides additional information to add to the genotype-phenotype spectrum for both MSH6 and PMS2 mutations.

EFFECTS OF THE ANTIMUTAGENS VANILLIN AND CINNAMALDEHYDE ON SPONTANEOUS MUTATION IN E. COLI LACL STRAINS AND ON GLOBAL GENE EXPRESSION IN SALMONELLA TA104 AND HUMAN HEPG2 CELLS

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Effects of the Antimutagens Vanillin and Cinnamaldehyde on Spontaneous Mutation in E. coli lacI Strains and on Global Gene Epression in Salmonella TAlO4 and Human HepG2 Cells In previous work we have shown that vanillin (VAN) and cinnamaldehyde (CIN) are dietary antimutag...

Severe neonatal epileptic encephalopathy and KCNQ2 mutation: neuropathological substrate?

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Charlotte eDalen Meurs-Van Der Schoor

2014-12-01

Full Text Available Background:Neonatal convulsions are clinical manifestations in a heterogeneous group of disorders with different etiology and outcome. They are attributed to several genetic causes. Methods:We describe a patient with intractable neonatal seizures who died from respiratory compromise during a status epilepticus. Results:This case report provides EEG, MRI, genetic analysis and neuropathological data. Genetic analysis revealed a de novo heterozygous missense mutation in the KCNQ2 gene, which encodes a subunit of a voltage-gated potassium channel. KCNQ2 gene mutation is associated with intractable neonatal seizures. EEG, MRI data as well as mutation analysis have been described in other KCNQ2 cases. Postmortem neuropathologic investigation revealed mild malformation of cortical development with increased heterotopic neurons in the deep white matter compared to an age-matched control subject. The new finding of this study is the combination of a KCNQ2 mutation and the cortical abnormalities. Conclusions:KCNQ2 mutations should be considered in neonates with refractory epilepsy of unknown cause. The mild cortical malformation is an important new finding, though it remains unknown whether these cortical abnormalities are due to the KCNQ2 mutation or are secondary to the refractory seizures.

JAK2, MPL, and CALR mutations in Chinese Han patients with essential thrombocythemia.

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Wang, Jing; Zhang, Biao; Chen, Bing; Zhou, Rong-Fu; Zhang, Qi-Guo; Li, Juan; Yang, Yong-Gong; Zhou, Min; Shao, Xiao-Yan; Xu, Yong; Xu, Xi-Hui; Ouyang, Jian; Xu, Jingyan; Ye, Qing

2017-04-01

Mutations in Janus kinase 2 (JAK2), myeloproliferative leukemia (MPL), and CALR are highly relevant to Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms. Assessing the prevalence of molecular mutations in Chinese Han patients with essential thrombocythemia (ET), and correlating their mutational profile with disease characteristics/phenotype. Of the 110 subjects studied, 62 carried the JAK2 V617F mutation, 21 had CALR mutations, one carried an MPL (W515) mutation, and 28 had non-mutated JAK2, CALR, and MPL (so-called triple-negative ET). Mutations in JAK2 exon 12 were not detected in any patient. Two ET patients had both CALR and JAK2 V617F mutations. Comparing the hematological parameters of the patients with JAK2 mutations with those of the patients with CALR mutations showed that the ET patients with CALR mutations were younger (p = 0.045) and had higher platelet counts (p = 0.043). Genotyping for CALR could be a useful diagnostic tool for JAK2/MPL-negative ET, since the data suggest that CALR is much more prevalent than MPL, therefore testing for CALR should be considered in patients who are JAK2 negative as its frequency is almost 20 times that of MPL mutation.

The peanut lectin-binding glycoproteins of human epidermal keratinocytes

International Nuclear Information System (INIS)

Morrison, A.I.; Keeble, S.; Watt, F.M.

1988-01-01

The peanut lectin (PNA) is known to bind more strongly to keratinocytes that are undergoing terminal differentiation than to proliferating keratinocytes. In order to investigate the significance of this change in cell-surface carbohydrate authors have identified the PNA-binding glycoproteins of cultured human keratinocytes and antibodies against them. Two heavily glycosylated bands of 110 and 250 kDa were resolved by PAGE of [ 14 C]galactose- or [ 14 C]mannose- and [ 14 C]glucosamine-labeled cell extracts eluted with galactose from PNA affinity columns. The higher molecular weight band was also detected on PNA blots of unlabeled cell extracts transferred to nitrocellulose. Both bands were sensitive to pronase digestion, but only the 250-kDa band was digested with trypsin. A rabbit antiserum that we prepared (anti-PNA-gp) immunoprecipitated both bands from cell extracts. In contrast to PNA, anti-PNA-gp bound equally to proliferating and terminally differentiating cells, indicating that some epitope(s) of the PNA-binding glycoproteins is present on the cell surface prior to terminal differentiation. When keratinocytes grown as a monolayer in low-calcium medium were switched to medium containing 2 mM calcium ions in order to induce desmosome formation and stratification, there was a dramatic redistribution of the PNA-binding glycoproteins, which became concentrated at the boundaries between cells. This may suggest a role for the glycoproteins in cell-cell interactions during stratification

Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology