A Ca2+‐dependent actin modulator from vertebrate smooth muscle

FEBS Letters

Small, J.V.¹  Hinssen, H.¹  Sobieszek, A.¹ 

[1] Institute of Molecular Biology, Austrian Academy of Sciences, Billrothstr. 11, A-5020 Salzburg, Austria

关键词: Smooth muscle;    Actin filament;    Actin modulator;    Ca2+-dependence;   

DOI  :  10.1016/0014-5793(84)80051-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A protein of M _r ≈ 85 000 has been isolated and purified from pig stomach smooth muscle that modulates the polymer state of actin in a Ca²⁺-dependent manner. When added either to preformed F-actin filaments or to G-actin, prior to polymerisation, the modulator induces the formation of shorter filaments. The average filament length in the presence of the modulator is directly dependent on its molar ratio to actin indicating a stoichiometric rather than a catalytic type of interaction. When mixed with G-actin the modulator forms a stable complex with two actin monomers; this complex is presumed to act as a potent nucleus for actin polymerisation. The dynamics of the interaction with F-actin suggests a direct severing of actin filaments by the modulator via a binding to intrafilamentous actins.

【 授权许可】

Unknown