OsCPL3 is involved in brassinosteroid signaling by regulating OsGSK2 stability
OsCPL3 is involved in brassinosteroid signaling by regulating OsGSK2 stability
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DOI：
10.1111/jipb.13311
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发表时间：
2022-07-04
影响因子：
11.4
通讯作者：
Liang, Yun-Kuan
中科院分区：
文献类型：
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作者：
Gong, Luping;Liao, Shenghao;Liang, Yun-Kuan
糖原合成酶激酶3(GSK3)蛋白通过磷酸化多种底物，在植物生长发育过程中对油菜素类固醇(BR)信号起关键作用。然而，GSK3蛋白的稳定性和活性本身是如何被调节的还不是很清楚。在此，我们在体外和体内证明了水稻C末端结构域磷酸酶样蛋白3(OsCPL3)与水稻中的OsGSK2发生物理相互作用。OsCPL3在根、叶和叶片关节等组织器官中广泛表达，并被外源BR诱导表达。OsCPL3定位于细胞核，在Ser-222和Thr-284残基上使OsGSK2去磷酸化，调节其蛋白周转和激酶活性，进而影响抗BRASSINAZOLE 1(BZR1)和BR信号的降解。OsCPL3功能的丧失导致了OsGSK2丰度的增加和OsBZR1水平的降低，导致BR反应减弱和植物形态的变化，包括对作物生产力至关重要的半矮化、叶片直立和籽粒大小。这些结果揭示了OsCPL3以前未被认识到的作用，并为植物中严格控制的BR信号通路增加了另一层复杂性。
Glycogen synthase kinase 3 (GSK3) proteins play key roles in brassinosteroid (BR) signaling during plant growth and development by phosphorylating various substrates. However, how GSK3 protein stability and activity are themselves modulated is not well understood. Here, we demonstrate in vitro and in vivo that C-TERMINAL DOMAIN PHOSPHATASE-LIKE 3 (OsCPL3), a member of the RNA Pol II CTD phosphatase-like family, physically interacts with OsGSK2 in rice (Oryza sativa). OsCPL3 expression was widely detected in various tissues and organs including roots, leaves and lamina joints, and was induced by exogenous BR treatment. OsCPL3 localized to the nucleus, where it dephosphorylated OsGSK2 at the Ser-222 and Thr-284 residues to modulate its protein turnover and kinase activity, in turn affecting the degradation of BRASSINAZOLE-RESISTANT 1 (BZR1) and BR signaling. Loss of OsCPL3 function resulted in higher OsGSK2 abundance and lower OsBZR1 levels, leading to decreased BR responsiveness and alterations in plant morphology including semi-dwarfism, leaf erectness and grain size, which are of fundamental importance to crop productivity. These results reveal a previously unrecognized role for OsCPL3 and add another layer of complexity to the tightly controlled BR signaling pathway in plants.