Reciprocal regulation between the negative regulator PP2CG1 phosphatase and the positive regulator OST1 kinase confers cold response in Arabidopsis
Reciprocal regulation between the negative regulator PP2CG1 phosphatase and the positive regulator OST1 kinase confers cold response in Arabidopsis
复制标题
负调节因子 PP2CG1 磷酸酶和正调节因子 OST1 激酶之间的相互调节赋予拟南芥冷反应
DOI：
10.1111/jipb.13100
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发表时间：
2021-05-31
影响因子：
11.4
通讯作者：
Ding, Yanglin
中科院分区：
文献类型：
--
作者：
Lv, Jian;Liu, Jingyan;Ding, Yanglin
据报道，蛋白质磷酸化和去磷酸化在植物冷反应中发挥重要作用。此外，磷酸调节反馈是动植物生物过程和应激反应的保守机制。然而，鲜为人知的是，在植物对冷胁迫的反应中，蛋白激酶和蛋白磷酸酶形成了调节反馈回路。在此，我们报道了开放气孔 1 (OST1) 和蛋白磷酸酶 2C G GROUP 1 (PP2CG1) 在冷应激反应期间相互调节活性。 PP2CG1和OST1的相互作用受到冷应激的抑制，导致细胞质和细胞核中的OST1不受PP2CG1的抑制而释放。有趣的是，冷激活的 OST1 磷酸化 PP2CG1 以抑制其磷酸酶活性，从而放大植物中的冷信号传导。 PP2CG1 及其同源物 PP2CG2 的突变可增强冷冻耐受性，而 PP2CG1 的过度表达会降低冷冻耐受性。此外，PP2CG1 在冷应激下负向调节 C-重复结合因子 (CBF) 的蛋白质水平。我们的结果揭示了植物冷反应中由 PP2CG1 磷酸酶和 OST1 蛋白激酶介导的磷/去磷调节反馈环路。
Protein phosphorylation and dephosphorylation have been reported to play important roles in plant cold responses. In addition, phospho-regulatory feedback is a conserved mechanism for biological processes and stress responses in animals and plants. However, it is less well known that a regulatory feedback loop is formed by the protein kinase and the protein phosphatase in plant responses to cold stress. Here, we report that OPEN STOMATA 1 (OST1) and PROTEIN PHOSPHATASE 2C G GROUP 1 (PP2CG1) reciprocally regulate the activity during the cold stress response. The interaction of PP2CG1 and OST1 is inhibited by cold stress, which results in the release of OST1 at the cytoplasm and nucleus from suppression by PP2CG1. Interestingly, cold-activated OST1 phosphorylates PP2CG1 to suppress its phosphatase activity, thereby amplifying cold signaling in plants. Mutations of PP2CG1 and its homolog PP2CG2 enhance freezing tolerance, whereas overexpression of PP2CG1 decreases freezing tolerance. Moreover, PP2CG1 negatively regulates protein levels of C-REPEAT BINDING FACTORs (CBFs) under cold stress. Our results uncover a phosphor/dephosphor-regulatory feedback loop mediated by PP2CG1 phosphatase and OST1 protein kinase in plant cold responses.