Arabidopsis CBL-Interacting Protein Kinases Regulate Carbon/Nitrogen-Nutrient Response by Phosphorylating Ubiquitin Ligase ATL31.
Arabidopsis CBL-Interacting Protein Kinases Regulate Carbon/Nitrogen-Nutrient Response by Phosphorylating Ubiquitin Ligase ATL31.
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DOI：
10.1016/j.molp.2017.01.005
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发表时间：
2017-04
期刊：
影响因子：
27.5
通讯作者：
Shigetaka Yasuda;Shoki Aoyama;Y. Hasegawa;Takeo Sato;J. Yamaguchi
中科院分区：
文献类型：
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作者：
Shigetaka Yasuda;Shoki Aoyama;Y. Hasegawa;Takeo Sato;J. Yamaguchi
响应于有效碳（C）和氮（N）营养的比例，植物调节其代谢，生长和发育，这一过程称为C/N营养反应。然而，C/N营养信号的分子基础仍然很不清楚。在本研究中，我们鉴定了三种钙调神经磷酸酶B样（CBL）相互作用蛋白激酶（CIPK），CIPK 7，CIPK 12和CIPK 14，作为拟南芥萌发后生长过程中C/N营养反应的关键调节因子。CIPK 7、CIPK 12和CIPK 14的单敲除突变体表现出对高C/低N条件的敏感性，这在其三敲除突变体中得到增强，表明它们在C/N营养响应中起负面作用并且至少部分地冗余地起作用。此外，这些CIPKs被发现通过14-3-3蛋白的磷酸化依赖性泛素化和蛋白酶体降解来调节ATL 31的功能，ATL 31是一种参与C/N营养反应的泛素连接酶。CIPK 7、CIPK 12和CIPK 14与ATL 31物理相互作用，CIPK 14与CBL 8作用，以Ca 2+依赖性方式直接磷酸化ATL 31。进一步的分析表明，这些CIPK是ATL 31磷酸化和稳定化所必需的，ATL 31磷酸化和稳定化介导14-3-3蛋白响应于C/N-营养条件的降解。这些发现为蛋白磷酸化介导的C/N营养信号提供了新的见解。
In response to the ratio of available carbon (C) and nitrogen (N) nutrients, plants regulate their metabolism, growth, and development, a process called the C/N-nutrient response. However, the molecular basis of C/N-nutrient signaling remains largely unclear. In this study, we identified three CALCINEURIN B-LIKE (CBL)-INTERACTING PROTEIN KINASES (CIPKs), CIPK7, CIPK12, and CIPK14, as key regulators of the C/N-nutrient response during the post-germination growth inArabidopsis. Single-knockout mutants of CIPK7, CIPK12, and CIPK14 showed hypersensitivity to high C/low N conditions, which was enhanced in their triple-knockout mutant, indicating that they play a negative role and at least partly function redundantly in the C/N-nutrient response. Moreover, these CIPKs were found to regulate the function of ATL31, a ubiquitin ligase involved in the C/N-nutrient response via the phosphorylation-dependent ubiquitination and proteasomal degradation of 14-3-3 proteins. CIPK7, CIPK12, and CIPK14 physically interacted with ATL31, and CIPK14, acting with CBL8, directly phosphorylated ATL31 in a Ca2+-dependent manner. Further analyses showed that these CIPKs are required for ATL31 phosphorylation and stabilization, which mediates the degradation of 14-3-3 proteins in response to C/N-nutrient conditions. These findings provide new insights into C/N-nutrient signaling mediated by protein phosphorylation.