title: The Hepatitis C Virus-Induced Membranous Web and Associated Nuclear Transport Machinery Limit Access of Pattern Recognition Receptors to Viral Replication Sites.
abstract: Hepatitis C virus (HCV) is a positive-strand RNA virus of the Flaviviridae family and a major cause of liver disease worldwide. HCV replicates in the cytoplasm, and the synthesis of viral proteins induces extensive rearrangements of host cell membranes producing structures, collectively termed the membranous web (MW). The MW contains the sites of viral replication and assembly, and we have identified distinct membrane fractions derived from HCV-infected cells that contain replication and assembly complexes enriched for viral RNA and infectious virus, respectively. The complex membrane structure of the MW is thought to protect the viral genome limiting its interactions with cytoplasmic pattern recognition receptors (PRRs) and thereby preventing activation of cellular innate immune responses. Here we show that PRRs, including RIG-I and MDA5, and ribosomes are excluded from viral replication and assembly centers within the MW. Furthermore, we present evidence that components of the nuclear transport machinery regulate access of proteins to MW compartments. We show that the restricted assess of RIG-I to the MW can be overcome by the addition of a nuclear localization signal sequence, and that expression of a NLS-RIG-I construct leads to increased immune activation and the inhibition of viral replication.
authors: Department of Cell Biology University of Alberta, Edmonton, Alberta, Canada.|Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.|Li Ka Shing Institute of Virology, Edmonton, Alberta, Canada.
authors: Christopher J
authors: CJ
authors: Neufeldt
authors: Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.|Li Ka Shing Institute of Virology, Edmonton, Alberta, Canada.
authors: Michael A
authors: MA
authors: Joyce
authors: Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America.
authors: Nicholas
authors: N
authors: Van Buuren
authors: Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.|Li Ka Shing Institute of Virology, Edmonton, Alberta, Canada.
authors: Aviad
authors: A
authors: Levin
authors: Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America.
authors: Karla
authors: K
authors: Kirkegaard
authors: Department of Immunology, University of Washington, Seattle, Washington, United States of America.
authors: Michael
authors: M
authors: Gale
authors: Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.|Li Ka Shing Institute of Virology, Edmonton, Alberta, Canada.
authors: D Lorne J
authors: DL
authors: Tyrrell
authors: Department of Cell Biology University of Alberta, Edmonton, Alberta, Canada.|Li Ka Shing Institute of Virology, Edmonton, Alberta, Canada.
authors: Richard W
authors: RW
authors: Wozniak
mesh_terms: D021581:Active Transport, Cell Nucleus; D002460:Cell Line; D002462:Cell Membrane / Q000821:virology; D016174:Hepacivirus / Q000502:physiology*; D006801:Humans; D019913:Nuclear Localization Signals / Q000378:metabolism; D012367:RNA, Viral / Q000302:isolation & purification; D051192:Receptors, Pattern Recognition / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication / Q000235:genetics*
chemical_list: D019913:Nuclear Localization Signals; D012367:RNA, Viral; D051192:Receptors, Pattern Recognition; D014764:Viral Proteins