Protein kinase C phosphorylates DNA topoisomerase I

FEBS Letters

Shimizi, Nobuyoshi¹  Samuels, D.Scott¹  Shimizu, Yoshiko¹ 

[1] Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA

关键词: Protein kinase C;    Topoisomerase I;    DNA-;    Protein phosphorylation;    Mitogenic signal transduction;    Nuclear target;    PKC;    protein kinase C;    TPA;    12-O-tetradecanoylphorbol-13-acetate;    FPLC;    fast protein liquid chromatography;    PMSF;    phenylmethylsulfonyl fluoride;    PS;    phosphatidylserine;    EGTA;    [ethylenebis(oxyethylenenitrilo)]tetraacetic acid;    SDS;    sodium dodecyl sulfate;    TCA;    trichloroacetic acid;   

DOI  :  10.1016/0014-5793(89)81493-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The induction of mammalian cell proliferation requires the expression of a specific set of genes. Tumor promoters stimulate cell growth by activating the Ca²⁺ and phospholipid-dependent protein kinase, protein kinase C (PKC). DNA topoisomerase I, a nuclear enzyme involved in transcription, was phosphorylated by activated PKC in vitro. Phosphorylation by PKC stimulated the DNA relaxation activity of topoisomerase I two- to three-fold. Therefore, DNA topoisomerase I is a substrate for PKC-mediated activation by phosphorylation and may serve as a nuclear target of mitogenic signals generated by tumor promoters in vivo.

【 授权许可】

Unknown