title: Hepatitis B virus X protein enhances NFkappaB activity through cooperating with VBP1.
abstract: Hepatitis B virus X protein (HBx) is essential for hepatitis B virus infection and exerts a pleiotropic effect on various cellular machineries. HBx has been also demonstrated as an indirect transcriptional transactivator of various different viral and cellular promoters. In addition, HBx is involved in the development of various liver diseases including hepatocellular carcinoma. However the mechanism of HBx in hepatocellular carcinogenesis remains largely unknown. In this study, to identify possible new cellular proteins interacting with HBx, we carried out yeast two-hybrid assay. We obtained several possible cellular partners including VBP1, a binding factor for VHL tumor suppressor protein. The direct physical interaction between HBx and VBP1 in vitro and in vivo was confirmed by immunoprecipitation assay. In addition, we found that VBP1 facilitates HBx-induced NFkappaB activation and cell proliferation. These results implicate the important role of HBx in the development of hepatocellular carcinoma through its interaction with VBP1.
authors.affiliation: Department of Microbiology, School of Bioscience and Biotechnology, Chungnam National University, Daejeon, Korea.
authors.forename: Sang Yong
authors.initials: SY
authors.lastname: Kim
authors.forename: Jin Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Jeong Ki
authors.initials: JK
authors.lastname: Kim
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hee Min
authors.initials: HM
authors.lastname: Lee
authors.forename: Mi Sun
authors.initials: MS
authors.lastname: Choi
authors.forename: Pil Jae
authors.initials: PJ
authors.lastname: Maeng
authors.forename: Jeong Keun
authors.initials: JK
authors.lastname: Ahn
mesh_terms: D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D006515:Hepatitis B virus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D007668:Kidney / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D018832:Molecular Chaperones; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000378:metabolism*; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D018832:Molecular Chaperones; D016328:NF-kappa B; D012333:RNA, Messenger; D015534:Trans-Activators; C108825:VBP1 protein, human; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein