Type 2C protein phosphatases directly regulate abscisic acid-activated protein kinases in Arabidopsis
Type 2C protein phosphatases directly regulate abscisic acid-activated protein kinases in Arabidopsis
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DOI：
10.1073/pnas.0907095106
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发表时间：
2009-10-13
影响因子：
11.1
通讯作者：
Shinozaki, Kazuo
中科院分区：
文献类型：
--
作者：
Umezawa, Taishi;Sugiyama, Naoyuki;Shinozaki, Kazuo
脱落酸（阿坝）信号在植物的逆境响应和发育过程中起着重要作用。已知蛋白磷酸酶2C（A组PP 2C）或SNF 1相关蛋白激酶2（III亚类SnRK 2）的亚类分别是阿坝信号传导的主要负或正调节剂。在这里，我们展示了这两个主要信号因子之间的物理和功能联系。A组PP 2C与SnRK 2s以各种组合物理相互作用，并通过活化环中多个Ser/Thr残基的去磷酸化有效地灭活ABA活化的SnRK 2s。这一步骤被RCAR/PYR阿坝受体响应于阿坝而抑制。然而，abil-1突变的PP 2C对受体没有应答，并且组成性失活SnRK 2。我们的研究结果表明，A组PP 2Cs作为“看门人”的子类III SnRK 2，解开一个重要的阿坝信号的调节机制。
Abscisic acid (ABA) signaling is important for stress responses and developmental processes in plants. A subgroup of protein phosphatase 2C (group A PP2C) or SNF1-related protein kinase 2 (subclass III SnRK2) have been known as major negative or positive regulators of ABA signaling, respectively. Here, we demonstrate the physical and functional linkage between these two major signaling factors. Group A PP2Cs interacted physically with SnRK2s in various combinations, and efficiently inactivated ABA-activated SnRK2s via dephosphorylation of multiple Ser/Thr residues in the activation loop. This step was suppressed by the RCAR/PYR ABA receptors in response to ABA. However the abi1 -1 mutated PP2C did not respond to the receptors and constitutively inactivated SnRK2. Our results demonstrate that group A PP2Cs act as ` gatekeepers' of subclass III SnRK2s, unraveling an important regulatory mechanism of ABA signaling.