SCFAtPP2-B11 modulates ABA signaling by facilitating SnRK2.3 degradation in Arabidopsis thaliana.
SCFAtPP2-B11 modulates ABA signaling by facilitating SnRK2.3 degradation in Arabidopsis thaliana.
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DOI：
10.1371/journal.pgen.1006947
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发表时间：
2017-08
期刊：
影响因子：
4.5
通讯作者：
Li X
中科院分区：
文献类型：
--
作者：
Cheng C;Wang Z;Ren Z;Zhi L;Yao B;Su C;Liu L;Li X
植物激素脱落酸(ABA)是植物对干旱等非生物胁迫反应的重要组成部分。当感受到ABA时，PYR/PYR1-like(PYL)/RCAR(RCAR)蛋白与共受体蛋白磷酸酶2Cs相互作用，激活Snf1-Related Protein Kinase2(SnRK2)，通过磷酸化多种靶蛋白来激活ABA信号。因此，SnRK2激酶是ABA信号的中央调节因子。然而，调控SnRK2降解的机制仍然难以捉摸。在这里，我们发现SnRK2.3被26S蛋白酶体系统降解，ABA促进其降解。我们发现SnRK2.3与AtPP2-B11直接相互作用。AtPP2-B11是一种F-box蛋白，是Skp1/cullin/F-box E3泛素连接酶复合体的一部分，通过特异性促进SnRK2.3的降解来负面调节植物对ABA的反应。ABA诱导了AtPP2-B11的表达，抑制AtPP2-B11的表达显著提高了植物在种子萌发和萌发后发育过程中对ABA的敏感性。过表达AtPP2-B11不影响ABA敏感性，但抑制SnRK2.3过表达系的ABA超敏表型。这些结果揭示了一种新的机制，通过AtPP2-B11特异性地降解SnRK2.3来减弱ABA信号和拟南芥的非生物胁迫反应。植物激素ABA在植物的生长发育和对环境刺激的反应中起着至关重要的作用。SnRK2是PYR/PYL-ABA-PP2C调控机制的重要组成部分，它激活一系列bZIP转录因子和离子转运蛋白。然而，人们对SnRK2周转的调控知之甚少。在本研究中，我们发现26S蛋白酶体能降解SnRK2s，ABA能促进SnRK2.3的降解。我们还发现F-box蛋白AtPP2-B11与拟南芥Skp1-like蛋白ASK1和ASK2相互作用，是Skp1/cullin/F-box E3泛素连接酶复合体的一个组成部分。AtPP2-B11特异性地相互作用并调节SnRK2.3的降解。AtPP2-B11是由ABA诱导的，抑制AtPP2-B11的表达显著提高了植物在种子萌发和萌发后发育过程中对ABA的敏感性。过表达AtPP2-B11不影响ABA敏感性，但抑制SnRK2.3过表达系的ABA超敏表型。这些结果揭示了AtPP2-B11特异性降解SnRK2.3以减弱ABA信号和植物对非生物胁迫反应的机制。
The phytohormone abscisic acid (ABA) is an essential part of the plant response to abiotic stressors such as drought. Upon the perception of ABA, pyrabactin resistance (PYR)/PYR1-like (PYL)/regulatory components of ABA receptor (RCAR) proteins interact with co-receptor protein phosphatase type 2Cs to permit activation Snf1-related protein kinase2 (SnRK2) kinases, which switch on ABA signaling by phosphorylating various target proteins. Thus, SnRK2 kinases are central regulators of ABA signaling. However, the mechanisms that regulate SnRK2 degradation remain elusive. Here, we show that SnRK2.3 is degradated by 26S proteasome system and ABA promotes its degradation. We found that SnRK2.3 interacts with AtPP2-B11 directly. AtPP2-B11 is an F-box protein that is part of a SKP1/Cullin/F-box E3 ubiquitin ligase complex that negatively regulates plant responses to ABA by specifically promoting the degradation of SnRK2.3. AtPP2-B11 was induced by ABA, and the knockdown of AtPP2-B11 expression markedly increased the ABA sensitivity of plants during seed germination and postgerminative development. Overexpression of AtPP2-B11 does not affect ABA sensitivity, but inhibits the ABA hypersensitive phenotypes of SnRK2.3 overexpression lines. These results reveal a novel mechanism through which AtPP2-B11 specifically degrades SnRK2.3 to attenuate ABA signaling and the abiotic stress response in Arabidopsis. The phytohormone ABA plays critical roles in both plant growth and development and the response to environmental stimuli. The SnRK2s are important components of the PYR/PYL-ABA-PP2C regulatory machine which activate a set of bZIP transcription factors and ion transporters. However, the regulation of SnRK2 turnover is poorly understood. In this work, we show that SnRK2s are degraded by 26S proteasome and ABA promotes SnRK2.3 degradation. We also show that an F-box protein, AtPP2-B11, interacts with Arabidopsis Skp1-like protein ASK1 and ASK2, is a component of a SKP1/Cullin/F-box E3 ubiquitin ligase complex. AtPP2-B11 interacts and regulates the degradation of SnRK2.3 specifically. AtPP2-B11 is induced by ABA and knockdown of AtPP2-B11 expression markedly increases ABA sensitivity of plants during seed germination and post-germinative development. Overexpression of AtPP2-B11 does not affect ABA sensitivity, but inhibits the ABA hypersensitive phenotypes of SnRK2.3 overexpression lines. These results reveal a mechanism through which AtPP2-B11 specifically degrades SnRK2.3 to attenuate the ABA signaling and plant responses to abiotic stress.
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SCF E3 连接酶 PP2-B11 在拟南芥应对盐胁迫中发挥积极作用。
影响因子：
6.9
作者：
Jia F;Wang C;Huang J;Yang G;Wu C;Zheng C
通讯作者：
Zheng C
DOI：
10.1126/science.1173041
发表时间：
2009-05-22
期刊：
Science (New York, N.Y.)
影响因子：
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Park SY;Fung P;Nishimura N;Jensen DR;Fujii H;Zhao Y;Lumba S;Santiago J;Rodrigues A;Chow TF;Alfred SE;Bonetta D;Finkelstein R;Provart NJ;Desveaux D;Rodriguez PL;McCourt P;Zhu JK;Schroeder JI;Volkman BF;Cutler SR
通讯作者：
Cutler SR
DOI：
10.1111/j.1365-313x.2010.04112.x
发表时间：
2010-03
期刊：
The Plant journal : for cell and molecular biology
影响因子：
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作者：
Santner A;Estelle M
通讯作者：
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影响因子：
11.6
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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