Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases.
Heat Shock Factor 1 Is a Substrate for p38 Mitogen-Activated Protein Kinases.
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DOI：
10.1128/mcb.00292-16
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发表时间：
2016-09-15
影响因子：
5.3
通讯作者：
Dinkova-Kostova AT
中科院分区：
文献类型：
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作者：
Dayalan Naidu S;Sutherland C;Zhang Y;Risco A;de la Vega L;Caunt CJ;Hastie CJ;Lamont DJ;Torrente L;Chowdhry S;Benjamin IJ;Keyse SM;Cuenda A;Dinkova-Kostova AT
热休克因子 1 (HSF1) 监测蛋白质组的结构完整性。 S326 处的磷酸化是 HSF1 激活的标志，但磷酸化该位点的激酶的身份仍然难以捉摸。我们在这里展示了饮食剂苯乙基异硫氰酸酯 (PEITC) 抑制热休克蛋白 90 (Hsp90)，这是 HSF1 的主要负调节因子；激活 p38 丝裂原激活蛋白激酶 (MAPK)；并增加 HSF1 的 S326 磷酸化、三聚化和核转位，以及荧光素酶报告基因以及内源原型 HSF1 靶标 Hsp70 的转录。在体外，p38 MAPK 家族的所有成员都能快速且化学计量地催化 S326 磷酸化。稳定敲低细胞系和抑制剂的使用表明，在 p38 MAPK 中，p38γ 是负责细胞中 HSF1 S326 磷酸化的主要亚型。蛋白酶质谱方法证实了 S326 磷酸化，并意外地揭示了 p38 MAPK 还催化 HSF1 S303/307 处的磷酸化，这是先前已知的抑制性翻译后修饰。因此，我们已经确定 p38 MAPKs 是 HSF1 磷酸化的高效催化剂。此外，我们的研究结果表明，p38 MAPK 激活的程度和持续时间是热休克反应的程度和持续时间的重要决定因素。
Heat shock factor 1 (HSF1) monitors the structural integrity of the proteome. Phosphorylation at S326 is a hallmark for HSF1 activation, but the identity of the kinase(s) phosphorylating this site has remained elusive. We show here that the dietary agent phenethyl isothiocyanate (PEITC) inhibits heat shock protein 90 (Hsp90), the main negative regulator of HSF1; activates p38 mitogen-activated protein kinase (MAPK); and increases S326 phosphorylation, trimerization, and nuclear translocation of HSF1, and the transcription of a luciferase reporter, as well as the endogenous prototypic HSF1 target Hsp70. In vitro, all members of the p38 MAPK family rapidly and stoichiometrically catalyze the S326 phosphorylation. The use of stable knockdown cell lines and inhibitors indicated that among the p38 MAPKs, p38γ is the principal isoform responsible for the phosphorylation of HSF1 at S326 in cells. A protease-mass spectrometry approach confirmed S326 phosphorylation and unexpectedly revealed that p38 MAPK also catalyzes the phosphorylation of HSF1 at S303/307, previously known repressive posttranslational modifications. Thus, we have identified p38 MAPKs as highly efficient catalysts for the phosphorylation of HSF1. Furthermore, our findings suggest that the magnitude and persistence of activation of p38 MAPK are important determinants of the extent and duration of the heat shock response.