title: Hepatitis C virus co-opts Ras-GTPase-activating protein-binding protein 1 for its genome replication.
abstract: We recently reported that Ras-GTPase-activating protein-binding protein 1 (G3BP1) interacts with hepatitis C virus (HCV) nonstructural protein (NS)5B and the 5' end of the HCV minus-strand RNA. In the current study we confirmed these observations using immunoprecipitation and RNA pulldown assays, suggesting that G3BP1 might be an HCV replication complex (RC) component. In replicon cells, transfected G3BP1 interacts with multiple HCV nonstructural proteins. Using immunostaining and confocal microscopy, we demonstrate that G3BP1 is colocalized with HCV RCs in replicon cells. Small interfering RNA (siRNA)-mediated knockdown of G3BP1 moderately reduces established HCV RNA replication in HCV replicon cells and dramatically reduces HCV replication-dependent colony formation and cell-culture-produced HCV (HCVcc) infection. In contrast, knockdown of G3BP2 has no effect on HCVcc infection. Transient replication experiments show that G3BP1 is involved in HCV genome amplification. Thus, G3BP1 is associated with HCV RCs and may be co-opted as a functional RC component for viral replication. These findings may facilitate understanding of the molecular mechanisms of HCV genome replication.
authors.affiliation: Shanghai Medical College, Fudan University, Shanghai 200032, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Yi
authors.forename: Tingting
authors.initials: T
authors.lastname: Pan
authors.forename: Xianfang
authors.initials: X
authors.lastname: Wu
authors.forename: Wuhui
authors.initials: W
authors.lastname: Song
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Charles M
authors.initials: CM
authors.lastname: Rice
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Macdonald
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Yuan
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D017931:DNA Primers; D016679:Genome, Viral; D016174:Hepacivirus / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008856:Microscopy, Fluorescence; D034741:RNA, Small Interfering; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017361:Viral Nonstructural Proteins / Q000502:physiology; D020703:ras GTPase-Activating Proteins / Q000502:physiology*
chemical_list: D017931:DNA Primers; D034741:RNA, Small Interfering; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D020703:ras GTPase-Activating Proteins