Regulation of mitotic function of Chk1 through phosphorylation at novel sites by cyclin-dependent kinase 1 (Cdk1)
Regulation of mitotic function of Chk1 through phosphorylation at novel sites by cyclin-dependent kinase 1 (Cdk1)
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DOI：
10.1111/j.1365-2443.2006.00955.x
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发表时间：
2006-05-01
期刊：
影响因子：
2.1
通讯作者：
Inagaki, M
中科院分区：
文献类型：
--
作者：
Shiromizu, T;Goto, H;Inagaki, M
Chk 1在317和345位被ATR磷酸化，以响应停滞的复制和遗传毒性应激。这种Chk 1激活被认为在预防过早有丝分裂中起关键作用。然而，Chk 1在有丝分裂中的行为在很大程度上仍然未知。我们报道了Chk 1在有丝分裂中被磷酸化。这种磷酸化的减少，观察到在中期后期过渡。二维磷酸肽图谱显示，Chk 1在体内的磷酸化位点与细胞周期蛋白依赖性蛋白激酶（Cdk）1或p38 MAP激酶在体外的磷酸化位点完全重叠。Ser 286和Ser 301被鉴定为Chk 1上的新磷酸化位点。用Cdk抑制剂丁内酯I处理诱导Chk 1-S301磷酸化的减少，尽管用p38特异性抑制剂SB 203580或siRNA处理没有。此外，电离辐射（IR）或紫外线（UV）光没有诱导Chk 1磷酸化Ser 317和Ser 345在诺考达唑逮捕有丝分裂细胞。这些观察结果意味着有丝分裂Chk 1功能的调节，通过Chk 1磷酸化在新的网站Cdk 1。
Chk1 is phosphorylated at Ser317 and Ser345 by ATR in response to stalled replication and genotoxic stresses. This Chk1 activation is thought to play critical roles in the prevention of premature mitosis. However, the behavior of Chk1 in mitosis remains largely unknown. Here we reported that Chk1 was phosphorylated in mitosis. The reduction of this phosphorylation was observed at the metaphase-anaphase transition. Two-dimensional phosphopeptide mapping revealed that Chk1 phosphorylation sites in vivo were completely overlapped with the in vitro sites by cyclin-dependent protein kinase (Cdk) 1 or by p38 MAP kinase. Ser286 and Ser301 were identified as novel phosphorylation sites on Chk1. Treatment with Cdk inhibitor butyrolactone I induced the reduction of Chk1-S301 phosphorylation, although treatment with p38-specific inhibitor SB203580 or siRNA did not. In addition, ionizing radiation (IR) or ultraviolet (UV) light did not induce Chk1 phosphorylation at Ser317 and Ser345 in nocodazole-arrested mitotic cells. These observations imply the regulation of mitotic Chk1 function through Chk1 phosphorylation at novel sites by Cdk1.