微管的动态不稳定性及其由EB蛋白调节的机制起源
Rui Zhang1, Gregory M Alushin2, Alan Brown3
1Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Cell
|August 4, 2015
概括
末端结合蛋白 (EB) 通过在GTP水解过程中与管结构相互作用来调节微管体动力学. 这些相互作用影响了微管的布局和生长,解释了微管末端的EB蛋白的行为.
科学领域:
- 生物化学
- 结构生物学
- 细胞生物学
背景情况:
- 微管 (MT) 的动态不稳定性对于细胞过程至关重要.
- 与EB蛋白一样,GTP水解和微管相关蛋白 (MAP) 调节MT动态.
研究的目的:
- 阐明EB蛋白调节微管力学的结构机制.
主要方法:
- 在高分辨率 (≤3.5 Å) 确定了六个微管的冷电子显微镜 (cryo-EM) 结构.
- 结构包括与GMPCPP,GTPγS或GDP结合的微管,并与kinesin或EB3共聚合.
主要成果:
- 在GTP水解过程中确定了α-tubulin的微妙构造变化,导致全球晶格重组和应变.
- 观察到EB3与GTPγS-MTs结合后,与GDP-MTs相比,具有明显扭曲的紧格子.
- 证明EB3促进GMPCPP的快速水解,这表明它在识别中间状态方面发挥了作用.
结论:
- 通过与GTP水解过程中形成的中间状态相互作用,EB蛋白调节生长中的微管末端的结构过渡.
- 这些发现解释了EB的终端追踪行为及其对微管力学的影响.
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