Okadaic acid uncouples myosin light chain phosphorylation and tension in smooth muscle

FEBS Letters

Tansey, M.G.²  Kamm, K.E.²  Stull, J.T.²  Karaki, H.¹  Hori, M.¹ 

[1] Department of Veterinary Pharmacology, Faculty of Agriculture, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan;Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75235, USA

关键词: Okadaic acid;    Smooth muscle relaxation;    Myosin light chain phosphorylation;    MLC;    20 kDa myosin light chain;    OA;    okadaic acid;    MLCK;    myosin light chain kinase;    SDS-PAGE;    sodium dodecyl sulfate polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(90)81272-P

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Tracheal smooth muscle precontracted with carbachol relaxes upon the addition of 3 μM okadaic add. Although cytosolic Ca²⁺ concentrations decrease, myosin light chain remains highly phosphorylated (50%). In smooth muscle treated with carbachol alone or carbachol plus okadaic acid ³²P is incorporated into a single peptide on myosin light chain which corresponds to the site phosphorylated by myosin light chain kinase. Treatment with okadaic acid alone does not result in myosin light chain phosphorylation or tension development. These results suggest that a cellular mechanism other than myosin light chain phosphorylation can regulate contractile tension.

【 授权许可】

Unknown