Mediator Subunit MED25 couples alternative splicing of JAZ genes with fine-tuning of jasmonate signalings
Mediator Subunit MED25 couples alternative splicing of JAZ genes with fine-tuning of jasmonate signalings
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介体亚基 MED25 将 JAZ 基因的选择性剪接与茉莉酸信号传导的微调结合起来
DOI：
10.1105/tpc.19.00583
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发表时间：
2020
期刊：
影响因子：
11.6
通讯作者：
Li Chuanyou
中科院分区：
文献类型：
--
作者：
Wu Fangming;Deng Lei;Zhai Qingzhe;Zhao Jiuhai;Chen Qian;Li Chuanyou
JASMONATE ZIM-DOMAIN （JAZ）转录抑制因子是植物JASMONATE （JA）信号转导的关键调控因子。在静息期，JAZ蛋白的c端Jas基序结合转录因子MYC2抑制JA信号传导。在激素激发后，Jas基元结合激素受体CORONATINE INSENSITIVE1，介导JAZs的蛋白酶体降解，从而允许中介亚基MED25激活MYC2。随后，植物通过反馈产生抑制MYC2的显性JAZ剪接变异体来脱敏JA信号。本文报道了拟南芥MED25通过募集剪接因子PRE-mRNA-PROCESSING PROTEIN 39a （PRP39a）和PRP40a调控jazz基因选择性剪接的机制功能。我们证明了ja诱导的jaz剪接变体的产生依赖于MED25， MED25招募PRP39a和PRP40a来促进jaz基因的完全剪接。因此，MED25与PRP39a和PRP40a组成一个模块，防止JAZ剪接变异体介导的JA信号过度脱敏。
JASMONATE ZIM-DOMAIN (JAZ) transcriptional repressors are key regulators of jasmonate (JA) signaling in plants. At the resting stage, the C-terminal Jas motifs of JAZ proteins bind the transcription factor MYC2 to repress JA signaling. Upon hormone elicitation, the Jas motif binds the hormone receptor CORONATINE INSENSITIVE1, which mediates proteasomal degradation of JAZs and thereby allowing the Mediator subunit MED25 to activate MYC2. Subsequently, plants desensitize JA signaling by feedback generation of dominant JAZ splice variants that repress MYC2. Here we report the mechanistic function of Arabidopsis (Arabidopsis thaliana) MED25 in regulating the alternative splicing ofJAZgenes through recruiting the splicing factors PRE-mRNA-PROCESSING PROTEIN 39a (PRP39a) and PRP40a. We demonstrate that JA-induced generation of JAZ splice variants depends on MED25 and that MED25 recruits PRP39a and PRP40a to promote the full splicing ofJAZgenes. Therefore, MED25 forms a module with PRP39a and PRP40a to prevent excessive desensitization of JA signaling mediated by JAZ splice variants.