Phorbol ester‐induced protein phosphorylation and contraction in sphincter smooth muscle of rabbit iris

FEBS Letters

Abdel-Latif, Ata A.¹  Howe, Philip H.¹ 

[1] Department of Cell and Molecular Biology, Medical College of Georgia, Augusta, GA 30912-3331, USA

关键词: Protein kinase;    Phosphorylation;    Myosin light chain;    Muscle contraction;    Phorbol ester;    Ca2+;    (Iris sphincter smooth muscle);    PDBu;    phorbol 12;    13-dibutyrate;    PMA;    phorbol-12-myristate-13-acetate;    PIP2;    phosphatidylinositol 4;    5-bisphosphate;    DG;    1;    2-diacylglycerol;    IP3;    inositol trisphosphate;    MLC;    myosin light chain;    CCh;    carbachol;    H-7;    1-(5-isoquinolinesulfonyl)-2-methylpiperazine;   

DOI  :  10.1016/0014-5793(87)80162-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Phorbol 12,13-dibutyrate (PDBu) was employed in studies designed to determine the role of C-kinase in muscle contraction in the iris sphincter. PDBu induced MLC phosphorylation and contraction in a dose- and time-dependent manner. Maximum responses exerted by PDBu were about 50–60% of that obtained with CCh, and were totally dependent on the presence of extracellular Ca²⁺. PDBu had no effect on basal IP₃ levels, however it blocked the CCh-stimulated accumulation of IP₃. PDBu-induced effects were potentiated by ionomycin, and inhibited by the C-kinase antagonist H-7. These results provide further evidence for the involvement of C-kinase in mediating the sustained phase of the contractile response in the iris sphincter.

【 授权许可】

Unknown