Identification of a dual-specificity protein phosphatase that inactivates a MAP kinase from Arabidopsis
Identification of a dual-specificity protein phosphatase that inactivates a MAP kinase from Arabidopsis
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DOI：
10.1046/j.1365-313x.1998.00327.x
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发表时间：
1998-12-01
期刊：
影响因子：
7.2
通讯作者：
Luan, S
中科院分区：
文献类型：
--
作者：
Gupta, R;Huang, YF;Luan, S
丝裂原活化蛋白激酶（MAPK）在植物对逆境和病原菌的应答中起着关键作用。MAPK的激活和失活涉及激酶结构域中苏氨酸和酪氨酸残基的磷酸化和去磷酸化。在这里，我们报告的拟南芥基因编码的双特异性蛋白磷酸酶能够水解磷酸丝氨酸/苏氨酸和磷酸酪氨酸蛋白质底物的鉴定。这种酶，命名为AtDsPTP 1（拟南芥双特异性蛋白酪氨酸磷酸酶），去磷酸化和失活的MARK成员，从同一植物的MARKWPK 4。丝氨酸取代高度保守的半胱氨酸废除AtDsPTP 1的磷酸酶活性，表明所有真核生物的双特异性蛋白磷酸酶的保守催化机制。
Mitogen-activated protein kinases (MAPKs) play a key role in plant responses to stress and pathogens. Activation and inactivation of MAPKs involve phosphorylation and dephosphorylation on both threonine and tyrosine residues in the kinase domain. Here we report the identification of an Arabidopsis gene encoding a dual-specificity protein phosphatase capable of hydrolysing both phosphoserine/threonine and phosphotyrosine in protein substrates. This enzyme, designated AtDsPTP1 (Arabidopsis thaliana dual-specificity protein tyrosine phosphatase), dephosphorylated and inactivated AtlWPK4, a MARK member from the same plant. Replacement of a highly conserved cysteine by serine abolished phosphatase activity of AtDsPTP1, indicating a conserved catalytic mechanism of dual-specificity protein phosphatases from all eukaryotes.