scholarly journals The N-terminal helix α0 of hepatitis C virus NS3 protein dictates the subcellular localization and stability of NS3/NS4A complex

Virology ◽  
2012 ◽  
Vol 422 (2) ◽  
pp. 214-223 ◽  
Author(s):  
Ying He ◽  
Leiyun Weng ◽  
Rui Li ◽  
Li Li ◽  
Tetsuya Toyoda ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Subcellular Localization ◽  
Ns3 Protein

scholarly journals Subcellular Localization, Stability, andtrans-Cleavage Competence of the Hepatitis C Virus NS3-NS4A Complex Expressed in Tetracycline-Regulated Cell Lines

2000 ◽  
Vol 74 (5) ◽  
pp. 2293-2304 ◽  
Author(s):  
Benno Wölk ◽  
Domenico Sansonno ◽  
Hans-Georg Kräusslich ◽  
Franco Dammacco ◽  
Charles M. Rice ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Subcellular Localization ◽  
Cell Lines ◽  
Expression System ◽  
Subcellular Fractionation ◽  
Amino Terminal ◽  
Serine Protease Domain ◽  
Ns3 Protein ◽  
Regulated Gene Expression

ABSTRACT A tetracycline-regulated gene expression system and a panel of novel monoclonal antibodies were used to examine the subcellular localization, stability, and trans-cleavage competence of the hepatitis C virus (HCV) NS3-NS4A complex in inducible cell lines. The NS3 serine protease domain and the full-length NS3 protein expressed in the absence of the NS4A cofactor were diffusely distributed in the cytoplasm and nucleus. Coexpression of NS4A, however, directed NS3 to the endoplasmic reticulum (ER) or an ER-like modified compartment, as demonstrated by colocalization with 3,3′-dihexyloxacarbocyanine iodide, protein disulfide isomerase, and calnexin, as well as subcellular fractionation analyses. In addition, coexpression with NS4A dramatically increased the intracellular stability of NS3 (mean protein half-life of 26 versus 3 h) and allowed for NS4A-dependent trans-cleavage at the NS4B-NS5A junction. Deletion analyses revealed that the hydrophobic amino-terminal domain of NS4A was required for ER targeting of NS3. These results demonstrate the importance of studying HCV proteins in their biological context and define a well-characterized cell culture system for further analyses of the NS3-NS4A complex and the evaluation of novel antiviral strategies against hepatitis C.

685 IMMUNIZATION AGAINST HEPATITIS C VIRUS USING A PEPTIDE FROM NS3 PROTEIN LINKED TO MODULINS DERIVED FROM STAPHYLOCOCCUS EPIDERMIDIS

2010 ◽  
Vol 52 ◽  
pp. S267
Author(s):  
M. Durantez ◽  
C. Fayole ◽  
N. Casares ◽  
V. Belsue ◽  
J.I. Riezu-Boj ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Staphylococcus Epidermidis ◽  
Ns3 Protein

scholarly journals Isolation of RNA Aptamers Specific to the NS3 Protein of Hepatitis C Virus from a Pool of Completely Random RNA

Virology ◽  
1997 ◽  
Vol 237 (2) ◽  
pp. 270-282 ◽  
Author(s):  
P.K.R. Kumar ◽  
Keigo Machida ◽  
Petri T. Urvil ◽  
Nobuko Kakiuchi ◽  
Daesety Vishnuvardhan ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Aptamers ◽  
Ns3 Protein

scholarly journals NS3 protein of Hepatitis C virus associates with the tumour suppressor p53 and inhibits its function in an NS3 sequence-dependent manner

2006 ◽  
Vol 87 (6) ◽  
pp. 1703-1713 ◽  
Author(s):  
Lin Deng ◽  
Motoko Nagano-Fujii ◽  
Motofumi Tanaka ◽  
Yuki Nomura-Takigawa ◽  
Masanori Ikeda ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Subcellular Localization ◽  
Serine Protease ◽  
Protease Activity ◽  
Hcv Rna ◽  
Dependent Manner ◽  
Diffuse Type ◽  
Serine Protease Activity ◽  
Tumour Suppressor P53

The N-terminal 198 residues of NS3 (NS3-N) of Hepatitis C virus (HCV) subtype 1b obtained from 29 patients, as well as full-length NS3 (NS3-Full), were analysed for their subcellular localization, interaction with the tumour suppressor p53 and serine protease activity in the presence and absence of the viral cofactor NS4A. Based on the subcellular-localization patterns in the absence of NS4A, NS3-N sequences were classified into three groups, with each group exhibiting either dot-like, diffuse or a mixed type of localization. Chimeric NS3-Full sequences, each consisting of an individual NS3-N and a shared C-terminal sequence, showed the same localization patterns as those of the respective NS3-N. Site-directed mutagenesis experiments revealed that a single or a few amino acid substitutions at a particular position(s) of NS3-N altered the localization pattern. Interestingly, NS3 of the dot-like type, either NS3-N or NS3-Full, interacted with p53 more strongly than that of the diffuse type, in both the presence and the absence of NS4A. Moreover, NS3-N of the dot-like type suppressed trans-activating activity of p53 more strongly than that of the diffuse type. Serine protease activity did not differ significantly between the two types of NS3. In HCV RNA replicon-harbouring cells, physical interaction between NS3 and p53 was observed consistently and p53-mediated transcriptional activation was suppressed significantly compared with HCV RNA-negative control cells. Our results collectively suggest the possibility that NS3 plays an important role in the hepatocarcinogenesis of HCV by interacting differentially with p53 in an NS3 sequence-dependent manner.

scholarly journals DNA Vaccination Protects Mice against Challenge with Listeria monocytogenes Expressing the Hepatitis C Virus NS3 Protein

2003 ◽  
Vol 71 (11) ◽  
pp. 6372-6380 ◽  
Author(s):  
Benjamin E. Simon ◽  
Kenneth A. Cornell ◽  
Tina R. Clark ◽  
Sunwen Chou ◽  
Hugo R. Rosen ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Listeria Monocytogenes ◽  
Immune Responses ◽  
Bacterial Pathogen ◽  
Cell Responses ◽  
Ns3 Protein ◽  
Plasmid Dna Vaccine ◽  
In Vivo Induction

ABSTRACT The goal of this study was to develop a new surrogate challenge model for use in evaluating protective cell-mediated immune responses against hepatitis C virus (HCV) antigens. The use of recombinant Listeria monocytogenes organisms which express HCV antigens provides novel tools with which to assay such in vivo protection, as expression of immunity against this hepatotropic bacterial pathogen is dependent on antigen-specific CD8+ T lymphocytes. A plasmid DNA vaccine encoding a ubiquitin-NS3 fusion protein was generated, and its efficacy was confirmed by in vivo induction of NS3-specific, gamma interferon-secreting T cells following vaccination of BALB/c mice. These immunized mice also exhibited specific in vivo protection against subsequent challenge with a recombinant L. monocytogenes strain (TC-LNS3) expressing the NS3 protein. Notably, sublethal infection of naive mice with strain TC-LNS3 induced similar NS3-specific T-cell responses. These findings suggest that recombinant strains of L. monocytogenes expressing HCV antigens should prove useful for evaluating, or even inducing, protective immune responses against HCV antigens.

scholarly journals The Arginine-1493 Residue in QRRGRTGR1493G Motif IV of the Hepatitis C Virus NS3 Helicase Domain Is Essential for NS3 Protein Methylation by the Protein Arginine Methyltransferase 1

2001 ◽  
Vol 75 (17) ◽  
pp. 8031-8044 ◽  
Author(s):  
Jaerang Rho ◽  
Seeyoung Choi ◽  
Young Rim Seong ◽  
Joonho Choi ◽  
Dong-Soo Im
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Binding ◽  
Rna Helicase ◽  
Full Length ◽  
Arginine Residue ◽  
Protein Methylation ◽  
Helicase Domain ◽  
Rna Helicases ◽  
Ns3 Protein

ABSTRACT The NS3 protein of hepatitis C virus (HCV) contains protease and RNA helicase activities, both of which are likely to be essential for HCV propagation. An arginine residue present in the arginine-glycine (RG)-rich region of many RNA-binding proteins is posttranslationally methylated by protein arginine methyltransferases (PRMTs). Amino acid sequence analysis revealed that the NS3 protein contains seven RG motifs, including two potential RG motifs in the 1486-QRRGRTGRG-1494 motif IV of the RNA helicase domain, in which arginines are potentially methylated by PRMTs. Indeed, we found that the full-length NS3 protein is arginine methylated in vivo. The full-length NS3 protein and the NS3 RNA helicase domain were methylated by a crude human cell extract. The purified PRMT1 methylated the full-length NS3 and the RNA helicase domain, but not the NS3 protease domain. The NS3 helicase bound specifically and comigrated with PRMT1 in vitro. Mutational analyses indicate that the Arg1493 in the QRR1488GRTGR1493G region of the NS3 RNA helicase is essential for NS3 protein methylation and that Arg1488 is likely methylated. NS3 protein methylation by the PRMT1 was decreased in the presence of homoribopolymers, suggesting that the arginine-rich motif IV is involved in RNA binding. The results suggest that an arginine residue(s) in QRXGRXGR motif IV conserved in the virus-encoded RNA helicases can be posttranslationally methylated by the PRMT1.

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