Evangelista M, Klebl B M, Tong A H, Webb B A, Leeuw T, Leberer E, Whiteway M, Thomas D Y, Boone C
Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
J Cell Biol. 2000 Jan 24;148(2):353-62. doi: 10.1083/jcb.148.2.353.
Type I myosins are highly conserved actin-based molecular motors that localize to the actin-rich cortex and participate in motility functions such as endocytosis, polarized morphogenesis, and cell migration. The COOH-terminal tail of yeast myosin-I proteins, Myo3p and Myo5p, contains an Src homology domain 3 (SH3) followed by an acidic domain. The myosin-I SH3 domain interacted with both Bee1p and Vrp1p, yeast homologues of human WASP and WIP, adapter proteins that link actin assembly and signaling molecules. The myosin-I acidic domain interacted with Arp2/3 complex subunits, Arc40p and Arc19p, and showed both sequence similarity and genetic redundancy with the COOH-terminal acidic domain of Bee1p (Las17p), which controls Arp2/3-mediated actin nucleation. These findings suggest that myosin-I proteins may participate in a diverse set of motility functions through a role in actin assembly.
I型肌球蛋白是高度保守的基于肌动蛋白的分子马达，定位于富含肌动蛋白的皮质，并参与诸如内吞作用、极化形态发生和细胞迁移等运动功能。酵母肌球蛋白-I蛋白Myo3p和Myo5p的COOH末端尾巴包含一个Src同源结构域3（SH3），其后是一个酸性结构域。肌球蛋白-I的SH3结构域与Bee1p和Vrp1p相互作用，Bee1p和Vrp1p分别是人类WASP和WIP的酵母同源物，它们是连接肌动蛋白组装和信号分子的衔接蛋白。肌球蛋白-I的酸性结构域与Arp2/3复合体亚基Arc40p和Arc19p相互作用，并且与控制Arp2/3介导的肌动蛋白成核的Bee1p（Las17p）的COOH末端酸性结构域具有序列相似性和遗传冗余性。这些发现表明，肌球蛋白-I蛋白可能通过在肌动蛋白组装中的作用参与多种运动功能。
