CELL-CYCLE REGULATION OF HUMAN WEE1
CELL-CYCLE REGULATION OF HUMAN WEE1
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DOI：
10.1002/j.1460-2075.1995.tb07210.x
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发表时间：
1995-05-15
期刊：
影响因子：
11.4
通讯作者：
RUSSELL, P
中科院分区：
文献类型：
--
作者：
MCGOWAN, CH;RUSSELL, P
WEE 1激酶通过催化CDC 2/细胞周期蛋白B激酶的抑制性酪氨酸磷酸化负调节进入有丝分裂。本文报道了对人WEE 1的研究。内源性WEE 1在SDS-PAGE中以类似于94 kDa的蛋白质迁移，明显大于在5 '端截短的原始人WEE 1 cDNA克隆编码的49 kDa蛋白质。抗体消耗实验表明，WEE 1占大多数的活性，磷酸化CDC 2的酪氨酸15在HeLa细胞裂解物的体外测定，因此，它可能有一个重要的作用，在人类细胞的有丝分裂控制。在S期阻滞的HeLa细胞中，未发现WEE 1活性升高，这表明未复制的DNA不会通过过度激活WEE 1来延迟M期。WEE 1活性在M期受到强烈抑制，表明WEE 1的负调节可能是在G（2）/M转换期间促进CDC 2/细胞周期蛋白B激酶活化的机制的一部分。在不存在蛋白磷酸酶抑制剂的情况下制备的样品中，M期WEE 1被重新激活，表明WEE 1被需要蛋白磷酸化的机制抑制。
WEE1 kinase negatively regulates entry into mitosis by catalyzing the inhibitory tyrosine phosphorylation of CDC2/cyclin B kinase. We report here an investigation of human WEE1, Endogenous WEE1 migrates as an similar to 94 kDa protein in SDS-PAGE, substantially larger than the 49 kDa protein encoded by the original human WEE1 cDNA clone that was truncated at the 5'-end. Antibody depletion experiments demonstrate that WEE1 accounts for most of the activity that phosphorylates CDC2 on Tyr15 in an in vitro assay of HeLa cell lysates, hence it is likely to have an important role in the mitotic control of human cells. WEE1 activity was not found to be elevated in HeLa cells arrested in S phase, suggesting that unreplicated DNA does not delay M phase by hyperactivating WEE1. WEE1 activity is strongly suppressed during M phase, suggesting that negative regulation of WEE1 could be part of the mechanism by which activation of CDC2/cyclin B kinase is promoted during the G(2)/M transition. M phase WEE1 is re-activated in samples prepared in the absence of protein phosphatase inhibitors, demonstrating that WEE1 is inhibited by a mechanism that requires protein phosphorylation.