The Golgi-associated protein GRASP65 regulates spindle dynamics and is essential for cell division
The Golgi-associated protein GRASP65 regulates spindle dynamics and is essential for cell division
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DOI：
10.1091/mbc.e04-12-1065
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发表时间：
2005-07-01
影响因子：
3.3
通讯作者：
Malhotra, V
中科院分区：
文献类型：
--
作者：
Sütterlin, C;Polishchuk, R;Malhotra, V
在有丝分裂开始时，哺乳动物细胞的中心粒周围高尔基体被转化成小片段，分散在整个胞质溶胶中。高尔基体相关蛋白GRASP 65参与了这一过程。为了解决GRASP 65在有丝分裂高尔基体片段化中的作用，我们通过RNAi从HeLa细胞中去除该蛋白。在缺乏GRASP 65的情况下，每个高尔基体堆叠的池的数量减少，而不影响高尔基体膜和蛋白质转运的整体组织。GRASP 65缺失的细胞进入有丝分裂，但在中期积累，染色质浓缩和多个异常纺锤体，最终死亡。虽然在两个纺锤体极中检测到了Centring和g-微管蛋白，但其他纺锤体极含有g-微管蛋白，而不是Centring。此外，我们提供了GRASP 65的C-末端的表达干扰细胞进入有丝分裂的证据。我们的研究结果表明，需要GRASP 65在纺锤体动力学的调节，而不是在高尔基体池的堆叠的直接作用。这种新的功能是除了先前建立的GRASP 65在G2/M转换，这是由其C-末端介导的负面作用。
At the onset of mitosis, the pericentriolar Golgi apparatus of mammalian cells is converted into small fragments, which are dispersed throughout the cytosol. The Golgi-associated protein GRASP65 is involved in this process. To address the role of GRASP65 in mitotic Golgi fragmentation, we depleted the protein from HeLa cells by RNAi. In the absence of GRASP65, the number of cisternae per Golgi stack is reduced without affecting the overall organization of Golgi membranes and protein transport. GRASP65-depleted cells entered mitosis, but accumulated in metaphase with condensed chromatin and multiple aberrant spindles and eventually died. Although Centring and g-tubulin were detected in two of the spindle poles, the other spindle poles contained g-tubulin, but not Centring. Furthermore, we provide evidence that the expression of the C-terminus of GRASP65 interferes with entry of cells into mitosis. Our results suggest the requirement for GRASP65 in the regulation of spindle dynamics rather than a direct role in the stacking of Golgi cisternae. This novel function is in addition to the previously established negative role of GRASP65 at the G2/M transition, which is mediated by its C-terminus.