Quantitative proteomic analysis of purified yeast kinetochores identifies a PP1 regulatory subunit
Quantitative proteomic analysis of purified yeast kinetochores identifies a PP1 regulatory subunit
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DOI：
10.1101/gad.1865909
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发表时间：
2009-12-15
影响因子：
10.5
通讯作者：
Biggins, Sue
中科院分区：
文献类型：
--
作者：
Akiyoshi, Bungo;Nelson, Christian R.;Biggins, Sue
动粒是一种控制染色体分离和细胞周期进程的大分子复合体。当姐妹动点从相反的极点向微管进行双向连接时，纺锤体检查点被静默。双向和纺锤体检查点受Ipl1/Aurora B蛋白激酶和蛋白磷酸酶I(PP1)相反活性之间的平衡调节。然而，对PP1在动粒的定位和活性的调节知之甚少。在这里，我们开发了一种方法来纯化着丝粒结合的动点，并使用定量蛋白质组学来鉴定Fin1蛋白是PP1调节亚基。Fin1/PP1复合体受磷酸化和14-3-3蛋白结合的调节。当Fin1本地化错误时，两极磁盘轴无法组装，但由于PP1活动，磁盘轴检查点被不适当地静音。这些数据表明，Fin1是一个PP1调节亚基，其空间和时间活性必须受到精确控制，以确保基因组的稳定性。
The kinetochore is a macromolecular complex that controls chromosome segregation and cell cycle progression. When sister kinetochores make bioriented attachments to microtubules from opposite poles, the spindle checkpoint is silenced. Biorientation and the spindle checkpoint are regulated by a balance between the Ipl1/Aurora B protein kinase and the opposing activity of protein phosphatase I (PP1). However, little is known about the regulation of PP1 localization and activity at the kinetochore. Here, we developed a method to purify centromere-bound kinetochores and used quantitative proteomics to identify the Fin1 protein as a PP1 regulatory subunit. The Fin1/PP1 complex is regulated by phosphorylation and 14-3-3 protein binding. When Fin1 is mislocalized, bipolar spindles fail to assemble but the spindle checkpoint is inappropriately silenced due to PP1 activity. These data suggest that Fin1 is a PP1 regulatory subunit whose spatial and temporal activity must be precisely controlled to ensure genomic stability.