Down-regulation of viral replication by adenoviral-mediated expression of siRNA against cellular cofactors for hepatitis C virus

Zhang, Jing; Yamada, Osamu; Sakamoto, Takashi; Yoshida, Hiroshi; Iwai, Takahiro; Matsushita, Yoshihisa; Shimamura, Hideo; Araki, Hiromasa; Shimotohno, Kunitada

doi:10.1016/j.virol.2003.11.023

Cited by 74 publications

(54 citation statements)

References 23 publications

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“…Previously, Zhang et al [57] also obtained the similar results by using siRNA targeting several cellular proteins, including PTB, hVAP-33 and La antigen. In this report, we have further demonstrated that PTB is directly involved in viral transcription by demonstrating that immunodepletion of PTB from the lysates inhibited RNA replication in a cell-free HCV RNA replication assay.…”

Section: E2supporting

confidence: 61%

Polypyrimidine-tract-binding Protein is a Component of the HCV RNA Replication Complex and Necessary for RNA Synthesis

et al. 2006

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The machinery for hepatitis C virus (HCV) RNA replication is still poorly characterized. The relationship between HCV RNA replication and translation is also not clear. We have previously shown that a cellular protein polypyrimidine-tract-binding protein (PTB) binds to HCV RNA at several different sites and modulates HCV translation in several ways. Here we show that PTB also participates in RNA replication. By bromouridine triphosphate (BrUTP) labeling and confocal microscopy of cells harboring an HCV replicon, we showed that the newly synthesized HCV RNA was localized to distinct structures in the cytoplasm, which also contain PTB. Membrane flotation analysis demonstrated that a fraction of cytoplasmic PTB was associated with a detergent-resistant membrane (DRM) structure consisting of lipid rafts, which also contained HCV nonstructural proteins and the human vesicle-associated membrane proteinassociated protein (hVAP-33). PTB in the DRM was resistant to protease digestion, but became sensitive after treatment with the raft-disrupting agents. PTB in the DRM consisted of multiple isoforms and the brain-specific paralog. By using small interfering RNA (siRNA) of PTB, we showed that silencing of the endogenous PTB reduced the replication of HCV RNA replicon. In a cell-free, de novo HCV RNA synthesis system, HCV RNA synthesis was inhibited by anti-PTB antibody. These studies together indicated that PTB is a part of the HCV RNA replication complex and participates in viral RNA synthesis. Thus, PTB has dual functions in HCV life cycle, including translation and RNA replication.

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Section: E2supporting

confidence: 61%

Polypyrimidine-tract-binding Protein is a Component of the HCV RNA Replication Complex and Necessary for RNA Synthesis

et al. 2006

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“…[146][147][148] This hypothesis is supported by the aberrant fractionation of NS5B in detergent soluble membranes and by the decreased HCV replication upon VAP-A and -B silencing or overexpression of dominant-negative VAPs. [146][147][148][149][150] Whether VAP-C also contributes to HCV replication remains to be confirmed, 149 as this protein is not expressed in liver tissue. The VAP-A-NS5A interaction appears to depend on the phosphorylation status of the viral protein.…”

Section: ©2 0 1 1 L a N D E S B I O S C I E N C E D O N O T D I S Tmentioning

confidence: 99%

Hepatitis c virus and host cell lipids: An intimate connection

Alvisi¹,

Madan²,

2011

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“…Host Cell Factors Involved in HCV RNA Replication-Apart from the viral proteins and CREs, several host cell factors play an important role for HCV RNA replication based on the criteria that RNA interference-mediated knockdown of each of these cellular genes and/or overexpression of dominant negative mutants decreases viral replication (55)(56)(57). The first one is the human vesicle-associated membrane protein-associated protein A (VAP-A) that was initially identified as an interaction partner of NS5A and NS5B (58).…”

Section: Components Of the Hcv Replication Complexmentioning

confidence: 99%

From Structure to Function: New Insights into Hepatitis C Virus RNA Replication

Appel

Schaller

Pénin

et al. 2006

Journal of Biological Chemistry

177

120

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With an estimated number of about 180 million affected people worldwide and a limited therapy option, infection with the hepatitis C virus (HCV) 2 is an important medical problem. Initial limitations in propagating HCV in cell culture have been overcome step-by-step in the past few years and culminated in the recent development of a system allowing efficient propagation of infectious HCV in tissue culture. Nevertheless, structural and biochemical studies of viral proteins as well as molecular analysis of viral RNA replication are still major challenges. The recent resolution of the three-dimensional structures of some HCV proteins or domains along with elegant reverse genetic and cell biological studies provided first insights into how HCV amplifies its RNA, exploits the cellular machinery, and eventually overcomes innate immune responses. Organization of the Viral GenomeHCV is a positive strand RNA virus that has been classified as the genus Hepacivirus in the Flaviviridae family. The HCV genome is an uncapped, linear molecule with a length of ϳ9600 nucleotides (nt; Fig. 1A). It carries a long open reading frame that is flanked at the 5Ј-and 3Ј-ends by short highly structured non-translated regions (NTRs). The 5Ј-NTR has a length of about 340 nt and contains an internal ribosome entry site (IRES) required for translation of the HCV genome (1). This RNA element binds the 40 S ribosomal subunit in the absence of other translation initiation factors in a way that the initiation codon is placed in the immediate vicinity of the P site (2). Part of the IRES (domain II) overlaps with RNA signals essential for viral replication (Fig. 1A) arguing for a possible role of domain II in regulating a translation-RNA replication switch. The 3Ј-NTR has a tripartite structure composed of an ϳ40-nt-long variable region downstream of the HCV coding sequence, a poly(U/UC) tract of heterogeneous length, and a highly conserved 98-nt-long sequence designated X-tail (Fig. 1A). Genetic studies have shown that a poly(U/UC) tract of at least ϳ25 nt as well as the complete X-tail are required for RNA replication in cell culture and for infectivity of the viral genome in vivo. An additional cis-acting RNA element (CRE) has been identified in the 3Ј-terminal coding region of NS5B (Fig. 1A). This CRE (designated 5BSL3.2) (3) forms a long distance RNA-RNA interaction with SL2 in the X-tail (4), which is indispensable for RNA replication.Expression of the viral proteins from the monocistronic genome is primarily achieved by production of a polyprotein that is proteolytically cleaved into the structural proteins (core, envelope proteins E1 and E2), the hydrophobic peptide p7, and the non-structural (NS) proteins NS2, NS3, NS4A, NS4B, NS5A, and NS5B (Fig. 1A) (1, 5). Processing of the core to p7 region is mediated by host cell signalases, and in the case of the core protein, in addition by signal peptide peptidase. All remaining cleavages are carried out by two viral proteases: the NS2/3 protease mediating cleavage between NS2 and NS3 and the NS3...

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Down-regulation of viral replication by adenoviral-mediated expression of siRNA against cellular cofactors for hepatitis C virus

Cited by 74 publications

References 23 publications

Polypyrimidine-tract-binding Protein is a Component of the HCV RNA Replication Complex and Necessary for RNA Synthesis

Polypyrimidine-tract-binding Protein is a Component of the HCV RNA Replication Complex and Necessary for RNA Synthesis

Hepatitis c virus and host cell lipids: An intimate connection

From Structure to Function: New Insights into Hepatitis C Virus RNA Replication

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