Chen Jiacai, Sui Xinying, Ma Binran, Li Yuetong, Li Na, Qiao Longfei, Yu Yanchong, Dong Chun-Hai
College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China.
Plant Cell Rep. 2022 Apr;41(4):1075-1085. doi: 10.1007/s00299-022-02838-1. Epub 2022 Feb 24.
Arabidopsis CPR5 is involved in regulation of ethylene signaling via two different ways: interacting with the ETR1 N-terminal domains, and controlling nucleocytoplasmic transport of ethylene-related mRNAs. The ETR1 receptor plays a predominant role in ethylene signaling in Arabidopsis thaliana. Previous studies showed that both RTE1 and CPR5 can directly bind to the ETR1 receptor and regulate ethylene signaling. RTE1 was suggested to promote the ETR1 receptor signaling by influencing its conformation, but little is known about the regulatory mechanism of CPR5 in ethylene signaling. In this study, we presented the data showing that both RTE1 and CPR5 bound to the N-terminal domains of ETR1, and regulated ethylene signaling via the ethylene receptor. On the other hand, the research provided evidence indicating that CPR5 could act as a nucleoporin to regulate the ethylene-related mRNAs export out of the nucleus, while RTE1 or its homolog (RTH) had no effect on the nucleocytoplasmic transport of mRNAs. Nuclear qRT-PCR analysis and poly(A)-mRNA in situ hybridization showed that defect of CPR5 restricted nucleocytoplasmic transport of mRNAs. These results advance our understanding of the regulatory mechanism of CPR5 in ethylene signaling.
拟南芥CPR5通过两种不同方式参与乙烯信号转导调控：与ETR1的N端结构域相互作用，以及控制乙烯相关mRNA的核质运输。ETR1受体在拟南芥的乙烯信号转导中起主要作用。先前的研究表明，RTE1和CPR5都能直接与ETR1受体结合并调控乙烯信号转导。有研究认为RTE1通过影响ETR1受体的构象来促进其信号转导，但关于CPR5在乙烯信号转导中的调控机制知之甚少。在本研究中，我们提供的数据表明，RTE1和CPR5都与ETR1的N端结构域结合，并通过乙烯受体调控乙烯信号转导。另一方面，该研究提供的证据表明，CPR5可作为核孔蛋白来调控乙烯相关mRNA从细胞核输出，而RTE1或其同源物（RTH）对mRNA的核质运输没有影响。细胞核定量逆转录聚合酶链反应分析和聚腺苷酸mRNA原位杂交表明，CPR5缺陷会限制mRNA的核质运输。这些结果增进了我们对CPR5在乙烯信号转导调控机制的理解。
