Activation of ATM and phosphorylation of p53 by heat shock
Activation of ATM and phosphorylation of p53 by heat shock
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DOI：
10.1038/sj.onc.1205196
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发表时间：
2002-02-07
期刊：
影响因子：
8
通讯作者：
Watanabe, M
中科院分区：
文献类型：
--
作者：
Miyakoda, M;Suzuki, K;Watanabe, M
p53蛋白响应于各种应激而被磷酸化。我们检测了正常人二倍体细胞在43 ℃热休克2小时后p53蛋白的磷酸化。我们发现，热休克刺激p53在Ser 15的磷酸化，而不是在Ser 20，而在4戈伊和10 J/m（2）的紫外线的X射线照射诱导p53在Ser 15的磷酸化和Ser 20不太明显。Ser 15的磷酸化增加也观察到热休克GM 638，SV 40转化的人成纤维细胞系。虽然X射线照射诱导GM 638细胞中Ser 6、9、20和37的磷酸化，但热休克不影响这些丝氨酸的磷酸化水平。我们观察到很少或没有磷酸化的p53在Ser 15在两个主要共济失调毛细血管扩张症成纤维细胞，这是有缺陷的ATM。使用体外激酶试验，我们证实，免疫沉淀ATM从热休克和X射线照射的正常人二倍体细胞可以磷酸化p53在Ser 15到一个类似的程度。这些结果表明，热休克诱导p53的磷酸化，特别是在Ser 15，其磷酸化是由ATM激酶介导的。
p53 protein is phosphorylated in response to various stresses. Here we examined phosphorylation of p53 protein in normal human diploid cells after heat shock at 43degreesC for 2 h. We found that heat shock stimulates phosphorylation of p53 at Ser15 but not at Ser20, while X-irradiation at 4 Gy and 10 J/m(2) of UV induces phosphorylation of p53 at Ser15 and less significantly at Ser20. Increased phosphorylation of Ser15 was also observed in heat shocked GM638, the SV40-transformed human fibroblast cell line. Although X-ray irradiation induced phosphorylation of Ser6, 9, 20, and 37 in GM638 cells, heat shock did not affect the phosphorylation level of these serines. We observed little or no phosphorylation of p53 at Ser15 in two primary ataxia telangiectasia fibroblast cells, that are defective in ATM. Using an in vitro kinase assay, we confirmed that immunoprecipitated ATM from both heat-shocked and X-irradiated normal human diploid cells can phosphorylate p53 at Ser15 to a similar extent. These results indicate that heat shock induces phosphorylation of p53, especially at Ser15, and its phosphorylation is mediated by ATM kinase.