Conformational diversity of dynactin sidearm and domain organization of its subunit p150.
Conformational diversity of dynactin sidearm and domain organization of its subunit p150.
复制标题
dynactin 侧臂的构象多样性及其亚基 p150 的结构域组织。
DOI：
10.1091/mbc.e20-01-0031
复制
发表时间：
2020
影响因子：
3.3
通讯作者：
and Yoko Y. Toyoshima
中科院分区：
文献类型：
--
作者：
Kei Saito;Takashi Murayama;Tomone Hata;Takuya Kobayashi;Keitaro Shibata;Saiko Kazuno;Tsutomu Fujimura;Takashi Sakurai;and Yoko Y. Toyoshima
动力蛋白是负端定向微管运动动力蛋白的主要调节因子。动力蛋白的侧臂对于结合微管和调节动力蛋白活性是必不可少的。尽管我们对动力蛋白骨架（Arp1杆）结构的理解最近有了很大的提高，但侧臂子复合物的结构细节仍然难以捉摸。在这里，我们报告的灵活性和不同的构象dynactin侧臂观察电子显微镜。使用纳米金标记和缺失突变体分析，我们确定了最大亚基p150的结构域组织，并发现其卷曲螺旋（CC1），动力蛋白结合结构域，采用折叠或延伸的形式。此外，整个侧臂表现出几种特征形式，它们之间的平衡取决于盐浓度。这些动力蛋白复合物的构象变化为理解它如何与微管结合和调节动力蛋白提供了线索。
Dynactin is a principal regulator of the minus-end directed microtubule motor dynein. The sidearm of dynactin is essential for binding to microtubules and regulation of dynein activity. Although our understanding of the structure of the dynactin backbone (Arp1 rod) has greatly improved recently, structural details of the sidearm subcomplex remain elusive. Here, we report the flexible nature and diverse conformations of dynactin sidearm observed by electron microscopy. Using nanogold labeling and deletion mutant analysis, we determined the domain organization of the largest subunit p150 and discovered that its coiled-coil (CC1), dynein-binding domain, adopted either a folded or an extended form. Furthermore, the entire sidearm exhibited several characteristic forms, and the equilibrium among them depended on salt concentrations. These conformational diversities of the dynactin complex provide clues to understanding how it binds to microtubules and regulates dynein.