Role of Protein Phosphatase1 Regulatory Subunit3 in mediating the abscisic acid response
Role of Protein Phosphatase1 Regulatory Subunit3 in mediating the abscisic acid response
复制标题
蛋白磷酸酶 1 调节亚基 3 在介导脱落酸反应中的作用
DOI：
10.1104/pp.20.01018
复制
发表时间：
2020
期刊：
影响因子：
7.4
通讯作者：
Hou Suiwen
中科院分区：
文献类型：
--
作者：
Zhang Jing;Qin Qianqian;Nan Xiaohui;Guo Zilong;Liu Yang;Jadoon Sawaira;Chen Yan;Zhao Lulu;Yan Longfeng;Hou Suiwen
蛋白磷酸酶1 （Protein phosphatase e1, PP1）在真核生物中发挥重要作用，包括植物激素反应，是一种由催化和调节亚基组成的全酶。动物基因组编码约200个pp1相互作用蛋白；相比之下，在植物中只有很少的报道。在本研究中，PP1调控亚单位3 （PP1R3）是一种与拟南芥（拟南芥）中PP1相互作用的蛋白，通过质谱分析进行了表征。PP1R3在多种植物组织中广泛表达，并在细胞核和细胞质中与1型蛋白磷酸酶（TOPPs）共定位。pp1r3突变体对脱落酸（ABA）敏感，类似于显性阴性突变体topopp4 -1或丧失功能的多重突变体topp1 - 4-3、topp8 - topp9、topp6/7/9、topp1/2/4-3/6/7/9和topp1/4-3/5/6/7/ 9（topp-7m）。topp-7m中约三分之二的差异表达基因表现出与inpp1r3-2相同的基因表达变化。在ABA的作用下，pp1r3 topp1 topp4-3和pp1r3 topp4-1的表型与pp1r3一致，而pp1r3 ABI1 -1表现出pp1r3和ABI1 -1（abscisic Acid Insensitive1突变[ABI1]）单突变的加性效应。此外，pp1r3可以部分恢复topp1 -1的ABA应答相关表型、基因表达和植株形态。PP1R3抑制TOPP酶活性，促进TOPP4的核定位。相比之下，ABA处理增加了细胞质中TOPP1和TOPP4的数量。重要的是，TOPP4的核定位部分恢复了TOPP4 -1的aba超敏表型。总之，我们的研究结果表明，PP1R3:TOPP全酶在细胞核中与ABI1平行作用，调节ABA信号传导。
Protein phosphatase1 (PP1) plays important roles in eukaryotes, including in plant hormone responses, and functions as a holoenzyme that consists of catalytic and regulatory subunits. Animal genomes encode ∼200 PP1-interacting proteins; by contrast, only a few have been reported in plants. In this study, PP1 Regulatory Subunit3 (PP1R3), a protein that interacts with PP1 in Arabidopsis (Arabidopsis thaliana), was characterized by mass spectrometry.PP1R3was widely expressed in various plant tissues and PP1R3 colocalized with Type One Protein Phosphatases (TOPPs) in the nucleus and cytoplasm. Thepp1r3mutants were hypersensitive to abscisic acid (ABA), similar to the dominant-negative mutanttopp4-1or the loss-of-function multiple mutantstopp1 topp4-3,topp8 topp9,topp6/7/9,topp1/2/4-3/6/7/9, andtopp1/4-3/5/6/7/8/9(topp-7m). About two-thirds of differentially expressed genes intopp-7mshowed the same gene expression changes as inpp1r3-2. In response to ABA, the phenotypes ofpp1r3 topp1 topp4-3andpp1r3 topp4-1were consistent with those ofpp1r3, whilepp1r3 abi1-1showed an additive effect of thepp1r3andabi1-1(mutation inAbscisic Acid Insensitive1[ABI1]) single mutants. Moreover,pp1r3could partially recover the ABA response-related phenotype, gene expression, and plant morphology oftopp4-1. PP1R3 inhibited TOPP enzyme activity and facilitated the nuclear localization of TOPP4. By contrast, ABA treatment increased the amounts of TOPP1 and TOPP4 in the cytoplasm. Importantly, nuclear localization of TOPP4 partially restored the ABA-hypersensitive phenotype oftopp4-1. Overall, our results suggest that the PP1R3:TOPP holoenzyme functions in parallel with ABI1 in the nucleus to regulate ABA signaling.