The functional effects of mutations Thr 673 → Asp and Ser702 → Asp at the Pro‐directed kinase phosophorylation sites in the C‐terminus of chicken gizzard caldesmon

FEBS Letters

Gusev, Nikolai B.¹  Redwood, Charles S.²  Marston, Steven B.² 

[1] Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation;Department of Cardiac Medicine, National Heart and Lung Institute, Dovehouse St., London, SW3 6 LY, UK

关键词: Caldesmon;    Smooth muscle;    MAP kinase;    p34cdc2 kinase;    Thin filament;    Regulation;    MAP kinase;    mitogen activated protein kinase;    p34cdc2 kinase;    34 kDa protein kinase encoded by the S. pombe cell division control 2 gene and its functional homologues in other species;    PIPES;    piperazine N;    N'-bis (2-ethanesulphonic acid);   

DOI  :  10.1016/0014-5793(93)81045-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We expressed the C-terminal 99 amino acids of chicken gizzard caldesmon (658C) and two point mutants in which the preferred phosphorylation sites of MAP kinase and p34^cdc2 kinase, Ser⁷⁰² and Thr⁶⁷³ were altered to aspartic acid. The T673D mutant was indistinguishable from 658C but S702D was not phosphorylated by MAP kinase, was significantly less potent as an inhibitor of actin-tropomyosin activation of myosin MgATPase, and bound less actin-tropomyosin at low concentrations. Thus Ser⁷⁰² is involved in the tropomyosin-dependent inhibitory mechanism of caldesmon, and its phosphorylation by MAP kinase or p34^cdc2 kinase could modulate caldesmon function.

【 授权许可】

Unknown