scholarly journals A Concerted Action of Hepatitis C Virus P7 and Nonstructural Protein 2 Regulates Core Localization at the Endoplasmic Reticulum and Virus Assembly

2011 ◽  
Vol 7 (7) ◽  
pp. e1002144 ◽  
Author(s):  
Bertrand Boson ◽  
Ophélia Granio ◽  
Ralf Bartenschlager ◽  
François-Loïc Cosset
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Assembly ◽  
Nonstructural Protein ◽  
Concerted Action ◽  
Nonstructural Protein 2

scholarly journals Structural and Functional Characterization of Nonstructural Protein 2 for Its Role in Hepatitis C Virus Assembly

2008 ◽  
Vol 283 (42) ◽  
pp. 28546-28562 ◽  
Author(s):  
Vlastimil Jirasko ◽  
Roland Montserret ◽  
Nicole Appel ◽  
Anne Janvier ◽  
Leah Eustachi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Assembly ◽  
Nonstructural Protein ◽  
Functional Characterization ◽  
Nonstructural Protein 2

scholarly journals Structural and Functional Studies of Nonstructural Protein 2 of the Hepatitis C Virus Reveal Its Key Role as Organizer of Virion Assembly

2010 ◽  
Vol 6 (12) ◽  
pp. e1001233 ◽  
Author(s):  
Vlastimil Jirasko ◽  
Roland Montserret ◽  
Ji Young Lee ◽  
Jérôme Gouttenoire ◽  
Darius Moradpour ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Virion Assembly ◽  
Functional Studies ◽  
Nonstructural Protein 2

scholarly journals NS5A Domain 1 and Polyprotein Cleavage Kinetics Are Critical for Induction of Double-Membrane Vesicles Associated with Hepatitis C Virus Replication

mBio ◽  
2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Inés Romero-Brey ◽  
Carola Berger ◽  
Stephanie Kallis ◽  
Androniki Kolovou ◽  
David Paul ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Viruses ◽  
Nonstructural Protein ◽  
Membrane Vesicles ◽  
Rna Replication ◽  
Concerted Action ◽  
Double Membrane ◽  
Positive Strand ◽  
Positive Strand Rna

ABSTRACTInduction of membrane rearrangements in the cytoplasm of infected cells is a hallmark of positive-strand RNA viruses. These altered membranes serve as scaffolds for the assembly of viral replication factories (RFs). We have recently shown that hepatitis C virus (HCV) infection induces endoplasmic reticulum-derived double-membrane vesicles (DMVs) representing the major constituent of the RF within the infected cell. RF formation requires the concerted action of nonstructural action of nonstructural protein (NS)3, -4A, protein (NS)3 -4A, -4B, -5A, and -5B. Although the sole expression of NS5A is sufficient to induce DMV formation, its efficiency is very low. In this study, we dissected the determinants within NS5A responsible for DMV formation and found that RNA-binding domain 1 (D1) and the amino-terminal membrane anchor are indispensable for this process. In contrast, deletion of NS5A D2 or D3 did not affect DMV formation but disrupted RNA replication and virus assembly, respectively. To identifycis- andtrans-acting factors of DMV formation, we established atranscleavage assay. We found that induction of DMVs requires full-length NS3, whereas a helicase-lacking mutant was unable to trigger DMV formation in spite of efficient polyprotein cleavage. Importantly, a mutation accelerating cleavage kinetics at the NS4B-5A site diminished DMV formation, while the insertion of an internal ribosome entry site mimicking constitutive cleavage at this boundary completely abolished this process. These results identify key determinants governing the biogenesis of the HCV RF with possible implications for our understanding of how RFs are formed in other positive-strand RNA viruses.IMPORTANCELike all positive-strand RNA viruses, hepatitis C virus (HCV) extensively reorganizes intracellular membranes to allow efficient RNA replication. Double-membrane vesicles (DMVs) that putatively represent sites of HCV RNA amplification are induced by the concerted action of viral and cellular factors. However, the contribution of individual proteins to this process remains poorly understood. Here we identify determinants in the HCV replicase that are required for DMV biogenesis. Major contributors to this process are domain 1 of nonstructural protein 5A and the helicase domain of nonstructural protein 3. In addition, efficient DMV induction depends onciscleavage of the viral polyprotein, as well as tightly regulated cleavage kinetics. These results identify key determinants governing the biogenesis of the HCV replication factory with possible implications for our understanding of how this central compartment is formed in other positive-strand RNA viruses.

scholarly journals Inhibitors of Endoplasmic Reticulum α-Glucosidases Potently Suppress Hepatitis C Virus Virion Assembly and Release

2010 ◽  
Vol 55 (3) ◽  
pp. 1036-1044 ◽  
Author(s):  
Xiaowang Qu ◽  
Xiaoben Pan ◽  
Jessica Weidner ◽  
Wenquan Yu ◽  
Dominic Alonzi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Hcv Rna ◽  
Virion Assembly ◽  
Subsequent Degradation ◽  
Important Host ◽  
Antiviral Targets ◽  
Sugar Derivatives

ABSTRACTα-Glucosidases I and II are endoplasmic reticulum-resident enzymes that are essential for N-linked glycan processing and subsequent proper folding of glycoproteins. In this report, we first demonstrate that downregulation of the expression of α-glucosidase I, II, or both in Huh7.5 cells by small hairpin RNA technology inhibited the production of hepatitis C virus (HCV). In agreement with the essential role of α-glucosidases in HCV envelope glycoprotein processing and folding, treatment of HCV-infected cells with a panel of imino sugar derivatives, which are competitive inhibitors of α-glucosidases, did not affect intracellular HCV RNA replication and nonstructural protein expression but resulted in the inhibition of glycan processing and subsequent degradation of HCV E2 glycoprotein. As a consequence, HCV virion assembly and secretion were inhibited. In searching for imino sugars with better antiviral activity, we found that a novel imino sugar, PBDNJ0804, had a superior ability to inhibit HCV virion assembly and secretion. In summary, we demonstrated that glucosidases are important host factor-based antiviral targets for HCV infection. The low likelihood of drug-resistant virus emergence and potent antiviral efficacy of the novel glucosidase inhibitor hold promise for its development as a therapeutic agent for the treatment of chronic hepatitis C.

Cyclosporine A inhibits hepatitis C virus nonstructural protein 2 through cyclophilin A

Hepatology ◽  
2009 ◽  
Vol 50 (5) ◽  
pp. 1638-1645 ◽  
Author(s):  
Sandra Ciesek ◽  
Eike Steinmann ◽  
Heiner Wedemeyer ◽  
Michael P. Manns ◽  
Johann Neyts ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cyclosporine A ◽  
Nonstructural Protein ◽  
Cyclophilin A ◽  
Nonstructural Protein 2

Analysis of N-terminal processing of hepatitis C virus nonstructural protein 2.

1994 ◽  
Vol 68 (4) ◽  
pp. 2731-2734 ◽  
Author(s):  
H Mizushima ◽  
M Hijikata ◽  
Y Tanji ◽  
K Kimura ◽  
K Shimotohno
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Nonstructural Protein 2

scholarly journals Adaptive mutations promote hepatitis C virus assembly by accelerating Core translocation to the endoplasmic reticulum

2020 ◽  
pp. jbc.RA120.016010
Author(s):  
Fuxiang Zheng ◽  
Ni Li ◽  
Yi Xu ◽  
Yuanping Zhou ◽  
Yi-Ping Li
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Virus Assembly ◽  
Buoyant Density ◽  
Virus Production ◽  
Adaptive Mutations ◽  
Huh7 Cells ◽  
Density Analysis

The envelopment of hepatitis C virus (HCV) is believed to occur primarily in the endoplasmic reticulum (ER)-associated membrane, and the translocation of viral Core protein from lipid droplets (LDs) to the ER is essential for the envelopment of viral particles. However, the factors involved in are not completely understood. Herein, we identified eight adaptive mutations that enhanced virus spread and infectivity of genotype 1a clone TNcc in hepatoma Huh7 cells through long-term culture adaptation and reverse genetic study. Of eight mutations, I853V in NS2 and C2865F in NS5B were found to be minimal mutation sets that enabled an increase in virus production without apparently affecting RNA replication, thus suggesting its roles in the post-replication stage of the HCV life cycle. Using a protease K protection and confocal microscopy analysis, we demonstrated that C2865F and the combination of I853V/C2865F enhanced virus envelopment by facilitating Core translocation from LDs to the ER. Buoyant density analysis revealed that I853V/C2865F contributed to the release of virion with a density of ~1.10 g/ml. Moreover, we demonstrated that NS5B directly interacted with NS2 at the protease domain, and that mutations I853V, C2865F, I853V/C2865F enhanced the interaction. In addition, C2865F also enhanced the interaction between NS5B and Core. In conclusion, this study demonstrated that adaptive mutations in NS2 and NS5B promoted HCV envelopment by accelerating Core translocation from LDs to the ER and reinforced the interaction between NS2 and NS5B. The findings facilitate our understanding of the assembly of HCV morphogenesis.

scholarly journals The Hepatitis C Virus Nonstructural Protein 4B Is an Integral Endoplasmic Reticulum Membrane Protein

Virology ◽  
2001 ◽  
Vol 284 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Thomas Hügle ◽  
Frauke Fehrmann ◽  
Elke Bieck ◽  
Michinori Kohara ◽  
Hans-Georg Kräusslich ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Membrane Protein ◽  
Nonstructural Protein ◽  
Endoplasmic Reticulum Membrane
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