Catalytic fragment of protein kinase C exhibits altered substrate specificity toward smooth muscle myosin light chain

FEBS Letters

Nakabayashi, Hiroki²  Huang, Kuo-Ping²  Sellers, James R.¹ 

[1] Laboratory of Molecular Cardiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892, USA

关键词: Protein kinase C;    Myosin light chain;    Phosphorylation;    PKC;    protein kinase C;    PKM;    the catalytic fragment of PKC;    MLCK;    myosin light chain kinase;    LC;    the light chain subunit of myosin;    PMA;    phorbol 12-myristate;    13-acetate;    DAG;    diacylglycerol;    PS;    phosphatidylserine;   

DOI  :  10.1016/0014-5793(91)81362-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Smooth muscle myosin light chain (LC) can be phosphorylated by myosin light chain kinase (MLCK) at Ser¹⁹ and Thr¹⁸ and by protein kinase C (PKC) at Thr⁹ and Ser¹ or Ser² under the in vitro assay conditions. Conversion of PKC to the spontaneously active protein kinase M (PKM) by proteolysis resulted in a change in the substrate specificity of the kinase. PKM phosphorylated both sets of sites in LC recognized by MLCK and PKC as analyzed by peptide mapping analysis. The PKM-catalyzed phosphorylation of these sites was not greatly affected by a MLCK inhibitor, ML-9, nor by the activators of MLCK, Ca²⁺ and calmodulin.

【 授权许可】

Unknown