The Role of Xgrip210 in γ-Tubulin Ring Complex Assembly and Centrosome Recruitment
The Role of Xgrip210 in γ-Tubulin Ring Complex Assembly and Centrosome Recruitment
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Xgrip210 在 γ-微管蛋白环复合物组装和中心体招募中的作用
DOI：
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发表时间：
2000
影响因子：
7.8
通讯作者：
Yixian Zheng
中科院分区：
文献类型：
--
作者：
Lijun Zhang;T. J. Keating;A. Wilde;G. Borisy;Yixian Zheng
从脊椎动物和无脊椎动物细胞质中纯化的γ-微管蛋白环复合物（γ-TuRC）是体外微管成核剂。结构研究表明，γTuRC是一种形状像锁紧垫圈的结构，顶部有一个帽。微管被认为是从γTuRC的无帽侧成核。因此，γTuRC的帽状结构远离微管的基部，使微管的末端呈尖帽状。在这里，我们报告了非洲爪蟾γTuRC的一个新的亚基Xgrip 210的克隆和鉴定。我们发现Xgrip 210是一个保守的中心体蛋白，对γTuRC的形成至关重要。使用免疫金标记，我们发现Xgrip 210定位于由γTuRC成核的微管的末端，并且其定位比γ-微管蛋白更远，朝向γ TuRC帽结构的尖端。Xgrip 210的免疫耗竭不仅阻断了γTuRC的组装，还阻断了γ-微管蛋白及其相互作用蛋白Xgrip 109向中心体的募集。这些结果表明，Xgrip 210是γTuRC帽结构的一个组件，是γTuRC组装所需的。
The γ-tubulin ring complex (γTuRC), purified from the cytoplasm of vertebrate and invertebrate cells, is a microtubule nucleator in vitro. Structural studies have shown that γTuRC is a structure shaped like a lock-washer and topped with a cap. Microtubules are thought to nucleate from the uncapped side of the γTuRC. Consequently, the cap structure of the γTuRC is distal to the base of the microtubules, giving the end of the microtubule the shape of a pointed cap. Here, we report the cloning and characterization of a new subunit of Xenopus γTuRC, Xgrip210. We show that Xgrip210 is a conserved centrosomal protein that is essential for the formation of γTuRC. Using immunogold labeling, we found that Xgrip210 is localized to the ends of microtubules nucleated by the γTuRC and that its localization is more distal, toward the tip of the γTuRC-cap structure, than that of γ-tubulin. Immunodepletion of Xgrip210 blocks not only the assembly of the γTuRC, but also the recruitment of γ-tubulin and its interacting protein, Xgrip109, to the centrosome. These results suggest that Xgrip210 is a component of the γTuRC cap structure that is required for the assembly of the γTuRC.
DOI：
10.1073/pnas.95.16.9295
发表时间：
1998
影响因子：
11.1
作者：
Schnackenberg,BJ;Khodjakov,A;Rieder,CL;Palazzo,RE
通讯作者：
Palazzo,RE
影响因子：
10.9
作者：
Smith，Adam L.;Wang，Phillip
通讯作者：
Wang，Phillip