title: Modulation of mitogen-activated protein kinase-activated protein kinase 3 by hepatitis C virus core protein.
abstract: Hepatitis C virus (HCV) is highly dependent on cellular proteins for its own propagation. In order to identify the cellular factors involved in HCV propagation, we performed protein microarray assays using the HCV core protein as a probe. Of ~9,000 host proteins immobilized in a microarray, approximately 100 cellular proteins were identified as HCV core-interacting partners. Of these candidates, mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) was selected for further characterization. MAPKAPK3 is a serine/threonine protein kinase that is activated by stress and growth inducers. Binding of HCV core to MAPKAPK3 was confirmed by in vitro pulldown assay and further verified by coimmunoprecipitation assay. HCV core protein interacted with MAPKAPK3 through amino acid residues 41 to 75 of core and the N-terminal half of kinase domain of MAPKAPK3. In addition, both RNA and protein levels of MAPKAPK3 were elevated in both HCV subgenomic replicon cells and cell culture-derived HCV (HCVcc)-infected cells. Silencing of MAPKAPK3 expression resulted in decreases in both protein and HCV infectivity levels but not in the intracellular HCV RNA level. We showed that MAPKAPK3 increased HCV IRES-mediated translation and MAPKAPK3-dependent HCV IRES activity was further increased by core protein. These data suggest that HCV core may modulate MAPKAPK3 to facilitate its own propagation.
authors.affiliation: National Research Laboratory of Hepatitis C Virus and Ilsong Institute of Life Science, Hallym University, Anyang, South Korea.
authors.forename: Huong T T
authors.initials: HT
authors.lastname: Ngo
authors.forename: Long V
authors.initials: LV
authors.lastname: Pham
authors.forename: Jong-Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Yun-Sook
authors.initials: YS
authors.lastname: Lim
authors.forename: Soon B
authors.initials: SB
authors.lastname: Hwang
mesh_terms: D002460:Cell Line; D002498:Centrifugation; D016174:Hepacivirus / Q000472:pathogenicity / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D040081:Protein Array Analysis; D011485:Protein Binding; D014176:Protein Biosynthesis; D025941:Protein Interaction Mapping; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014158:Transcription, Genetic; D015854:Up-Regulation; D014758:Viral Core Proteins / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus; C098416:MAP-kinase-activated kinase 3; D017346:Protein Serine-Threonine Kinases