title: Identification of HNRNPK as regulator of hepatitis C virus particle production.
abstract: Hepatitis C virus (HCV) is a major cause of chronic liver disease affecting around 130 million people worldwide. While great progress has been made to define the principle steps of the viral life cycle, detailed knowledge how HCV interacts with its host cells is still limited. To overcome this limitation we conducted a comprehensive whole-virus RNA interference-based screen and identified 40 host dependency and 16 host restriction factors involved in HCV entry/replication or assembly/release. Of these factors, heterogeneous nuclear ribonucleoprotein K (HNRNPK) was found to suppress HCV particle production without affecting viral RNA replication. This suppression of virus production was specific to HCV, independent from assembly competence and genotype, and not found with the related Dengue virus. By using a knock-down rescue approach we identified the domains within HNRNPK required for suppression of HCV particle production. Importantly, HNRNPK was found to interact specifically with HCV RNA and this interaction was impaired by mutations that also reduced the ability to suppress HCV particle production. Finally, we found that in HCV-infected cells, subcellular distribution of HNRNPK was altered; the protein was recruited to sites in close proximity of lipid droplets and colocalized with core protein as well as HCV plus-strand RNA, which was not the case with HNRNPK variants unable to suppress HCV virion formation. These results suggest that HNRNPK might determine efficiency of HCV particle production by limiting the availability of viral RNA for incorporation into virions. This study adds a new function to HNRNPK that acts as central hub in the replication cycle of multiple other viruses.
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Poenisch
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Metz
authors.affiliation: Department of Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarbrücken, Germany; Center for Biomedicine, European Academy Bozen/Bolzano (EURAC), Bolzano, Italy, Affiliated Institute of the University of Lübeck, Lübeck, Germany.
authors.forename: Hagen
authors.initials: H
authors.lastname: Blankenburg
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Alessia
authors.initials: A
authors.lastname: Ruggieri
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rupp
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Ilka
authors.initials: I
authors.lastname: Rebhan
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Diederich
authors.affiliation: ViroQuant Research Group Modeling, University of Heidelberg, Heidelberg, Germany; Institute for Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Kaderali
authors.affiliation: Center for Biomedicine, European Academy Bozen/Bolzano (EURAC), Bolzano, Italy, Affiliated Institute of the University of Lübeck, Lübeck, Germany.
authors.forename: Francisco S
authors.initials: FS
authors.lastname: Domingues
authors.affiliation: Department of Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarbrücken, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Albrecht
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Lohmann
authors.affiliation: ViroQuant-CellNetworks RNAi Screening Facility, University of Heidelberg, Heidelberg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Erfle
authors.affiliation: Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Bartenschlager
mesh_terms: D002478:Cells, Cultured; D057809:HEK293 Cells; D016174:Hepacivirus / Q000187:drug effects / Q000502:physiology*; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D006801:Humans; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000494:pharmacology; D012367:RNA, Viral / Q000378:metabolism; D012261:Ribonucleoproteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D014771:Virion / Q000187:drug effects / Q000502:physiology*; D019065:Virus Assembly / Q000187:drug effects / Q000235:genetics*; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics
chemical_list: D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D034741:RNA, Small Interfering; D012367:RNA, Viral; D012261:Ribonucleoproteins; C072074:HNRNPK protein, human