F-actin慢生长端的盖帽蛋白:红细胞原肌球调节蛋白

The Capping Protein on the Slow-growing End of Actin Filament:Erythrocyte Tropomodulin

红细胞原肌球调节蛋白(erythrocyte tropomodulin,E-Tmod)是从红细胞膜中提取的原肌球蛋白(tropomyosin,TM)的结合蛋白。其N-端有两个TM结合位点和一个TM依赖的actin结合位点,C-端有5个富含亮氨酸的重复序列和一个TM非依赖的actin结合位点。作为F-actin慢生长端唯一的盖帽蛋白,E-Tmod与TM的N-端结合并同时与actin结合,减慢由TM包被的F-actin的解聚速度。E-Tmod编码基因高度保守,在红细胞、心肌细胞等细胞中广泛表达。E-Tmod对于F-actin和细胞骨架的组织以及对细胞力学特性的保持具有至关重要的作用。

Erythrocyte tropomodulin（E-Tmod） is first isolated from human erythrocyte membrane as a TM-binding protein.Its N-terminus contains two TM-binding sites and one TM-dependent actin capping domain and C-terminus contains 5 leucine-rich repeats and a TM-independent actin capping domain.As the unique capping protein at the slow-growing end of F-actin,E-Tmod binds to N-terminus of TM and actin and decreases the TM-coated F-actin depolymerization.E-Tmod encoding gene is highly conserved and E-Tmod is distributed widely in erythrocytes and cardiomyocytes,etc.E-Tmod plays a pivotal role in organizing F-actin and cytoskeleton and maintaining the mechanical properties of the cells.