Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
Curr Opin Struct Biol. 2021 Feb;66:15-21. doi: 10.1016/j.sbi.2020.08.008. Epub 2020 Sep 29.
The nucleation of microtubules from αβ-tubulin dimers is an essential cellular process dependent on γ-tubulin complexes. Mechanistic understanding of the nucleation reaction was hampered by the lack of γ-tubulin complex structures at sufficiently high resolution. The recent technical developments in cryo-electron microscopy have allowed resolving the vertebrate γ-tubulin ring complex (γ-TuRC) structure at near-atomic resolution. These studies clarified the arrangement and stoichiometry of gamma-tubulin complex proteins in the γ-TuRC, characterized the surprisingly versatile integration of the small proteins MZT1/2 into the complex, and identified actin as an integral component of the γ-TuRC. In this review, we summarize the structural insights into the molecular architecture, the assembly pathway, and the regulation of the microtubule nucleation reaction.
微管蛋白二聚体从αβ-微管蛋白的成核是一种依赖于γ-微管蛋白复合物的基本细胞过程。由于缺乏足够高分辨率的γ-微管蛋白复合物结构，对成核反应的机制理解受到了阻碍。近年来，低温电子显微镜技术的发展使得脊椎动物γ-微管蛋白环复合物（γ-TuRC）的结构能够以近原子分辨率解析。这些研究阐明了γ-TuRC 中γ-微管蛋白复合物蛋白的排列和化学计量，描述了将小蛋白 MZT1/2 惊人地整合到复合物中的方式，并确定了肌动蛋白是 γ-TuRC 的一个组成部分。在这篇综述中，我们总结了对微管蛋白成核反应的分子结构、组装途径和调控的结构见解。
