BRCA1 phosphorylation by Aurora-A in the regulation of G2 to M transition (Retracted Article)
BRCA1 phosphorylation by Aurora-A in the regulation of G2 to M transition (Retracted Article)
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DOI：
10.1074/jbc.m311780200
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发表时间：
2004-05-07
影响因子：
4.8
通讯作者：
Ouchi, T
中科院分区：
文献类型：
--
作者：
Ouchi, M;Fujiuchi, N;Ouchi, T
Aurora-A/BTAK/STK 15定位于G（2）-M期的中心体，其激酶活性调节细胞周期的G（2）到M的转变。先前的研究表明，BRCA 1乳腺癌肿瘤抑制因子也定位于中心体，并且BRCA 1失活导致G（2）-M检查点的丢失。我们在这里证明了Aurora-A与BRCA 1物理结合并磷酸化。生物化学分析显示BRCA 1氨基酸1314 - 1863与Aurora-A结合。体外定点突变表明Aurora-A可使BRCA 1的Ser（308）磷酸化。针对BRCA 1的Ser（308）的抗磷酸化特异性抗体证明Ser（308）在体内被磷酸化。丝氨酸（308）的磷酸化增加，在早期M期时，极光-A活性也增加，这些影响可以消除电离辐射。与这些观察结果一致，小干扰RNA导致Aurora-A的急性缺失导致BRCA 1 Ser（308）磷酸化减少，而腺病毒Aurora-A的瞬时感染增加Ser（308）磷酸化。BRCA 1单一磷酸化位点的突变（S308 N），当在BRCA 1缺陷小鼠胚胎成纤维细胞中表达时，减少M期细胞的数量，其程度与野生型BRCA 1介导的DNA损伤诱导的G（2）阻滞相似。我们认为Aurora-A对BRCA 1的磷酸化在细胞周期的G（2）向M的转变中起作用。
Aurora-A/BTAK/STK15 localizes to the centrosome in the G(2)-M phase, and its kinase activity regulates the G(2) to M transition of the cell cycle. Previous studies have shown that the BRCA1 breast cancer tumor suppressor also localizes to the centrosome and that BRCA1 inactivation results in loss of the G(2)-M checkpoint. We demonstrate here that Aurora-A physically binds to and phosphorylates BRCA1. Biochemical analysis showed that BRCA1 amino acids 1314 - 1863 binds to Aurora-A. Site-directed mutagenesis indicated that Ser(308) of BRCA1 is phosphorylated by Aurora-A in vitro. Anti-phospho-specific antibodies against Ser(308) of BRCA1 demonstrated that Ser(308) is phosphorylated in vivo. Phosphorylation of Ser(308) increased in the early M phase when Aurora-A activity also increases; these effects could be abolished by ionizing radiation. Consistent with these observations, acute loss of Aurora-A by small interfering RNA resulted in reduced phosphorylation of BRCA1 Ser(308), and transient infection of adenovirus Aurora-A increased Ser(308) phosphorylation. Mutation of a single phosphorylation site of BRCA1 (S308N), when expressed in BRCA1-deficient mouse embryo fibroblasts, decreased the number of cells in the M phase to a degree similar to that with wild type BRCA1-mediated G(2) arrest induced by DNA damage. We propose that BRCA1 phosphorylation by Aurora-A plays a role in G(2) to M transition of cell cycle.