一个去泛素化酶参与植物ABA信号转导调控的研究

Deubiquitination, a kind of Post-translational modification, plays important functions in many aspects of cellular activities. Compared with in animals, the research of deubiquitination in plants is still rare. And its regulation of ABA signaling pathway has yet been reported to date. In our previous work, a deubiquitinating enzyme gene NRA1(Negatively Regulating ABA 1) was cloned. The non-function mutant was hypersensitive to ABA in germination and greening, and the root growth of the mutant is also sensitive to ABA; NRA1 is located in both nucleus and cytoplasm; the results of Y2H(Yeast two-hybrid) and BiFC(Bimolecular Fluorescence Complementation) showed NRA1 was interacted with ABI1, a negative regulator of ABA signaling transduction. These results illustrated NRA1 may regulate ABA signaling by deubiquitinating ABI1. Based on these former results, in this work, we will focus on studying the mechanism of NRA1 involved in ABA signaling pathway by resorting to the methods of Molecular Biology, Genetics and Biochemistry. The expression pattern analysis, deubiquiting activity assay, genetic analysis and et al., will also be carried out in this project. The final goal is to uncover the function of deubiquitination in regulating of ABA signaling transduction pathway.

去泛素化修饰是在生命活动的许多方面发挥着重要功能的一种翻译后修饰。与动物相比，它在植物中的研究还比较少，其对ABA信号通路的调控还未见报道。在本实验室前期的工作中我们克隆了一个去泛素化酶基因NRA1(Negatively Regulating ABA 1)，它的缺失突变体在种子萌发和转绿阶段对ABA超敏，且早期根发育对ABA敏感；NRA1蛋白定位在细胞质和细胞核中；Y2H（酵母双杂交）和BiFC（双分子荧光互补技术）的结果显示，ABA信号通路的负调控因子ABI1与NRA1有相互作用，表明NRA1可能是通过调节ABI1的去泛素化调控ABA信号转导。本项目将在此基础上，通过利用分子生物学、遗传学和生物化学等方法，对NRA1的表达模式、去泛素化酶活性及与底物进行深入系统的研究。以期了解此基因的特性及其参与ABA信号调控的机理，最终阐明去泛素化酶调控植物ABA信号转导的作用机制。