Metal-dependent protein phosphatase 1A functions as an extracellular signal-regulated kinase phosphatase
Metal-dependent protein phosphatase 1A functions as an extracellular signal-regulated kinase phosphatase
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金属依赖性蛋白磷酸酶 1A 充当细胞外信号调节激酶磷酸酶。
DOI：
10.1111/febs.12275
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发表时间：
2013-06-01
期刊：
影响因子：
5.4
通讯作者：
Sun, Jin-Peng
中科院分区：
文献类型：
--
作者：
Li, Rong;Gong, Zheng;Sun, Jin-Peng
蛋白质磷酸化是一种重要的翻译后修饰，它调控着细胞内信号转导的几乎各个方面。丝裂原活化蛋白激酶（MAPK）家族激酶细胞外信号调节激酶（ERK）的激活是许多细胞活动响应外界刺激的一个汇聚点。受到刺激时，ERK在其激活环上的苏氨酸202和酪氨酸204发生磷酸化，其活性显著增强。几种磷酸酶，如蛋白磷酸酶2A、HePTP和MAPK磷酸酶3，对这两个位点的ERK磷酸化进行下调，这对于在不同细胞过程中维持适当的ERK功能至关重要。然而，金属依赖性蛋白磷酸酶（PPM）家族的磷酸酶是否直接使ERK去磷酸化尚不清楚。在本研究中，我们发现PPM1A在表皮生长因子（EGF）刺激早期通过直接使ERK的pThr202位点去磷酸化而对ERK进行负向调控。进一步的动力学研究表明，关键残基参与了PPM1A对磷酸化ERK的识别。重要的是，通过PPM1A活性位点的碱性残基与ERK的pThr - Glu - pTyr基序相互作用，PPM1A相较于一组其他磷酸肽更倾向于磷酸化ERK肽序列。赖氨酸165和精氨酸33是PPM1A有效催化或磷酸底物结合所必需的，谷氨酰胺185和精氨酸186是PPM1A底物特异性的决定因素。PPM1A的精氨酸186与磷酸化ERK的谷氨酸203和pTyr204之间的相互作用被确定为磷酸化ERK - PPM1A相互作用的热点。结构化数字摘要：通过下拉实验表明PPM1A与ERK2发生物理相互作用（查看相互作用）；通过磷酸酶测定表明PPM1A使p38去磷酸化（查看相互作用：1，2）；通过下拉实验表明PPM1A与ERK2结合（查看相互作用）；通过磷酸酶测定表明PPM1A使ERK2去磷酸化（查看相互作用：1，2，3，4，5，6，7，8，9，10，11，12，13，14，15，16，17，18，19，20）
Protein phosphorylation is an important post-translational modification that regulates almost every aspect of signal transduction in cells. Activation of the mitogen-activated protein kinase (MAPK) family kinase extracellular signal-regulated kinase (ERK) is a point of convergence for many cellular activities in response to external stimulation. With stimuli, ERK activity is significantly increased by the phosphorylation of Thr202 and Tyr204 at its activation loop. Downregulation of ERK phosphorylation at these two sites by several phosphatases, such as protein phosphatase2A, HePTP and MAPK phosphatase3, is essential for maintaining appropriate ERK function in different cellular processes. However, it is unknown whether metal-dependent protein phosphatase (PPM) family phosphatases directly dephosphorylate ERK. In this study, we found that PPM1A negatively regulated ERK by directly dephosphorylating its pThr202 position early in EGF stimulation. Additional kinetic studies revealed that key residues participated in phospho-ERK recognition by PPM1A. Importantly, PPM1A preferred the phospho-ERK peptide sequence over a panel of other phosphopeptides through the interactions of basic residues in the active site of PPM1A with the pThr-Glu-pTyr motif of ERK. Whereas Lys165 and Arg33 were required for efficient catalysis or phosphosubstrate binding of PPM1A, Gln185 and Arg186 were determinants of PPM1A substrate specificity. The interaction between Arg186 of PPM1A and Glu203 and pTyr204 of phospho-ERK was identified as a hot-spot for phospho-ERKPPM1A interaction. Structured digital abstract PPM1A physically interacts with ERK2 by pull down (View interaction) PPM1A dephosphorylates p38 by phosphatase assay (View Interaction: 1, 2) PPM1A binds to ERK2 by pull down (View interaction) PPM1A dephosphorylates ERK2 by phosphatase assay (View Interaction: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)