NEK2A interacts with MAD1 and possibly functions as a novel integrator of the spindle checkpoint signaling
NEK2A interacts with MAD1 and possibly functions as a novel integrator of the spindle checkpoint signaling
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DOI：
10.1074/jbc.m314205200
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发表时间：
2004-05-07
影响因子：
4.8
通讯作者：
Yao, XB
中科院分区：
文献类型：
--
作者：
Lou, Y;Yao, JH;Yao, XB
有丝分裂中的染色体分离是由蛋白激酶信号级联调控的。一个称为纺锤体检查点的生化级联确保了有丝分裂过程中染色体分离的空间和时间顺序。在这里，我们报道了纺锤体检查点蛋白MAD1与NEK2A相互作用，NEK2A是人类尼杜拉曲霉NIMA激酶的同源基因。在体外和体内，MAD1通过位于MAD1 C端的亮氨酸拉链结构域与NEK2A相互作用。和MAD1一样，NEK2A定位于有丝分裂细胞的HeLa细胞动粒。通过小干扰RNA消除NEK2A不会阻止细胞在有丝分裂中，但会导致异常的过早染色体分离。NEK2A是MAD2所必需的，但MAD1、Bub1和HEC1不需要。这些被NEK2A消除或抑制的细胞表现为染色体桥表型，姐妹染色单体相互连接。此外，NEK2A的缺失还会影响诺康唑对纺锤体损伤所产生的有丝分裂检查点信号，从而影响有丝分裂逃逸，导致多核细胞的产生。我们的数据表明，NEK2A是一种动粒相关的蛋白激酶，对于忠实的染色体分离是必不可少的。我们假设NEK2A将MAD2分子动力学与纺锤体检查点信号联系起来。
Chromosome segregation in mitosis is orchestrated by protein kinase signaling cascades. A biochemical cascade named spindle checkpoint ensures the spatial and temporal order of chromosome segregation during mitosis. Here we report that spindle checkpoint protein MAD1 interacts with NEK2A, a human orthologue of the Aspergillus nidulans NIMA kinase. MAD1 interacts with NEK2A in vitro and in vivo via a leucine zipper-containing domain located at the C terminus of MAD1. Like MAD1, NEK2A is localized to HeLa cell kinetochore of mitotic cells. Elimination of NEK2A by small interfering RNA does not arrest cells in mitosis but causes aberrant premature chromosome segregation. NEK2A is required for MAD2 but not MAD1, BUB1, and HEC1 to associate with kinetochores. These NEK2A-eliminated or -suppressed cells display a chromosome bridge phenotype with sister chromatid inter-connected. Moreover, loss of NEK2A impairs mitotic checkpoint signaling in response to spindle damage by nocodazole, which affected mitotic escape and led to generation of cells with multiple nuclei. Our data demonstrate that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. We hypothesize that NEK2A links MAD2 molecular dynamics to spindle checkpoint signaling.