https://scholars.lib.ntu.edu.tw/handle/123456789/568770
標題: | The double-stranded RNA-activated kinase, PKR, can phosphorylate hepatitis D virus small delta antigen at functional serine and threonine residues | 作者: | Chen C.-W. Tsay Y.-G. Wu H.-L. Lee C.-H. Chen D.-S. PEI-JER CHEN |
公開日期: | 2002 | 出版社: | American Society for Biochemistry and Molecular Biology Inc. | 卷: | 277 | 期: | 36 | 起(迄)頁: | 33058-33067 | 來源出版物: | Journal of Biological Chemistry | 摘要: | Hepatitis D virus (HDV) encodes two proteins, the 24-kDa small delta antigen (S-HDAg) and 27-kDa large delta antigen (L-HDAg) in its single open reading frame. Both of them had been identified as nuclear phosphoproteins. Moreover, the phosphorylated form of S-HDAg was shown to be important for HDV replication. However, the kinase responsible for S-HDAg phosphorylation remains unknown. Therefore, we employed an ingel kinase assay to search candidate kinases and indeed identified a kinase with a molecular mass of about 68 kDa. Much evidence demonstrated this kinase to be the double-stranded RNA-activated kinase, PKR. The immunoprecipitated endogenous PKR was sufficient to catalyze S-HDAg phosphorylation, and the kinase activity disappeared in the PKR-depleted cell lysate. The S-HDAg and PKR could be co-immunoprecipitated together, and both of them co-located in the nucleolus. The LC/MS/MS analysis revealed that the serine 177, serine 180, and threonine 182 of S-HDAg were phosphorylated by PKR in vitro. This result was consistent with previous phosphoamino acid analysis indicating that serine and threonine were phosphorylation targets in S-HDAg. Furthermore, serine 177 was also shown to be the predominant phosphorylation site for S-HDAg purified the from cell line. In dominant negative PKR-transfected cells, the level of phosphorylated S-HDAg was suppressed, but replication of HDV was enhanced. Other than human immunodeficiency virus type 1 trans-activating protein (Tat), S-HDAg is another viral protein phosphorylated by PKR that may regulates HDV replication and viral response to interferon therapy. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984550587&doi=10.1074%2fjbc.M200613200&partnerID=40&md5=8c8298018a25a1e62d3212f972b0921a https://scholars.lib.ntu.edu.tw/handle/123456789/568770 |
ISSN: | 0021-9258 | DOI: | 10.1074/jbc.M200613200 | SDG/關鍵字: | Antigens; Assays; Cells; Immunology; Proteins; Viruses; Phosphorylation; RNA; double stranded RNA; hepatitis delta antigen; protein kinase; protein kinase R; transactivator protein; unclassified drug; article; cellular distribution; controlled study; Hepatitis delta virus; human; human cell; nonhuman; open reading frame; priority journal; protein expression; protein localization; protein phosphorylation; virus cell interaction; virus replication; Hepatitis delta virus; Human immunodeficiency virus; Human immunodeficiency virus 1 |
顯示於: | 臨床醫學研究所 |
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