title: Identification of hnRNPH1, NF45, and C14orf166 as novel host interacting partners of the mature hepatitis C virus core protein.
abstract: The hepatitis C virus core protein (HCVc) forms the viral nucleocapsid and is involved in viral persistence and pathogenesis, possibly by interacting with host factors to modulate viral replication and cellular functions. Here, we identified 36 cellular protein candidates by one-dimensional SDS-PAGE and LC-MS/MS-based proteomics after affinity purification with HCVc174, a matured form of HCVc from HCV-1b genotype, tagged with biotin and calmodulin-binding peptide/protein A at N- and C-termini, respectively. By pull-down and confocal imaging techniques, we confirmed that heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1), nuclear factor 45 (NF45), and C14orf166 are novel HCVc174-interacting host proteins, known to participate in mRNA metabolism, gene regulation, and microtubule organization, respectively. Unlike the other 2 proteins, NF45 interacted with HCVc174 in an RNA-dependent manner. These 3 proteins colocalized with ectopic HCVc-1b in both the cytoplasm and nucleus, which demonstrated their spatial interaction with naturally translocated HCVc174 after HCVc biogenesis. Such colocalization, however, shifted to the cytoplasm in cells with replicating virus of 1b or 2a genotype, indicating that active viral replication confined these interacting proteins in the cytoplasm. Collectively, our findings suggest that spatial interactions of hnRNPH1, NF45, and C14orf166 with HCVc174 likely modulate HCV or cellular functions during acute and chronic HCV infection.
authors.affiliation: Institute of Basic Medical Science, College of Medicine,  National Cheng Kung University , Tainan 70401, Taiwan, Republic of China.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Lee
authors.forename: Pao-Chi
authors.initials: PC
authors.lastname: Liao
authors.forename: Kung-Chia
authors.initials: KC
authors.lastname: Young
authors.forename: Christina L
authors.initials: CL
authors.lastname: Chang
authors.forename: Steve S L
authors.initials: SS
authors.lastname: Chen
authors.forename: Ting-Tsung
authors.initials: TT
authors.lastname: Chang
authors.forename: Ming-Derg
authors.initials: MD
authors.lastname: Lai
authors.forename: Shainn-Wei
authors.initials: SW
authors.lastname: Wang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D015967:Gene Expression Regulation, Viral; D005838:Genotype; D057809:HEK293 Cells; D016174:Hepacivirus / Q000378:metabolism*; D006526:Hepatitis C / Q000378:metabolism*; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods; D051903:Nuclear Factor 45 Protein / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D014758:Viral Core Proteins / Q000737:chemistry*; D014779:Virus Replication
chemical_list: C116747:HNRNPH2 protein, human; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D051903:Nuclear Factor 45 Protein; C435504:RTRAF protein, human; D015534:Trans-Activators; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus