The kinetochore protein Ndc10p is required for spindle stability and cytokinesis in yeast
The kinetochore protein Ndc10p is required for spindle stability and cytokinesis in yeast
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DOI：
10.1073/pnas.0405925102
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发表时间：
2005-04-12
影响因子：
11.1
通讯作者：
Bloom, KS
中科院分区：
文献类型：
--
作者：
Bouck, DC;Bloom, KS
出芽酵母的动粒由60多种蛋白质组成，并与120bp的着丝粒（CEN）DNA结合。动粒蛋白具有高度动态性，在定位上呈现出程序性的细胞周期变化。着丝粒特异性组蛋白Cse4p是少数几种稳定的动粒成分之一，在整个有丝分裂过程中都与CEN DNA结合。相比之下，在后期观察到其他几种动粒蛋白沿着极间微管分布并位于中区。内动粒蛋白Ndc10p在后期晚期富集在纺锤体中区。我们发现，在后期，Ndc10p被运输到中区极间微管的正端，这一过程需要生存素（Bir1p）——极光激酶（Ipl1p）复合物的一个成员，以及Cdc14p磷酸酶。此外，在有丝分裂过程中，Ndc10p对于一些重要的非动粒过程是必需的。缺乏功能性Ndc10p的细胞在后期表现出纺锤体稳定性缺陷，并且在胞质分裂过程中无法分裂隔膜环。后一种表型导致ndc10 - 1细胞出现细胞分离缺陷。我们提出，Ndc10p在后期维持纺锤体稳定性方面起直接作用，并在染色体分离后协调细胞分裂的完成。
The budding yeast kinetochore is comprised of >60 proteins and associates with 120 bp of centromeric (CEN) DNA. Kinetochore proteins are highly dynamic and exhibit programmed cell cycle changes in localization. The CEN-specific histone, Cse4p, is one of a few stable kinetochore components and remains associated with CEN DNA throughout mitosis. In contrast, several other kinetochore proteins have been observed along interpolar microtubules and at the midzone during anaphase. The inner kinetochore protein, Ndc10p, is enriched at the spindle midzone in late anaphase. We show that Ndc10p is transported to the plus-ends of interpolar microtubules at the midzone during anaphase, a process that requires survivin (Bir1p), a member of the aurora kinase(lpl1p)complex, and Cdc14p phosphatase. In addition, Ndc10p is required for essential non-kinetochore processes during mitosis. Cells lacking functional Ndc10p show defects in spindle stability during anaphase and failure to split the septin ring during cytokinesis. This latter phenotype leads to a cell separation defect in ndc10-1 cells. We propose that Ndc10p plays a direct role in maintaining spindle stability during anaphase and coordinates the completion of cell division after chromosome segregation.