ABA调控NUA参与SUMO化修饰的机制研究

Abscisic acid (ABA) is an important phytohormone. Searching downstream targets of ABA and completing ABA signaling pathway is helpful to recover its mechanism in molecular levels. NUA is a phosphorylated protein regulated by ABA, which is screened by phosphoproteomics. We have founded that nua displayed ABA hypersensitivity, indicating that NUA was involved in ABA signaling pathway. NUA is part of nuclear pore complex, which is participated in sumoylation and mRNA export. Our study founded that sumoylation levels were increased after ABA treatment. However, it is still unknown how ABA functions in sumoylation. Using approaches of biochemical cellular biology and genetics, we will investigate the mechanisms of NUA phosphorylation regulated by ABA, and make sure its phosphorylation sites, explore the relations between ABA and sumoylation, mRNA export which are regulated by NUA, clarify its functions and roles in ABA signaling, screen the kinases of NUA , to complete ABA signaling pathway.

脱落酸（abscisic acid，ABA）是一类重要的植物激素。寻找ABA下游靶蛋白，完善ABA信号通路，有助于从分子水平上揭示ABA的调控机理。NUA是通过磷酸化蛋白质组学筛选得到的一个被ABA磷酸化调控的蛋白。项目前期研究发现拟南芥nua突变体对ABA超敏感，表明NUA参与了ABA信号转导通路。NUA蛋白是核孔复合体的一部分，参与蛋白的SUMO化修饰及mRNA的出核过程。我们发现ABA处理使植物体内蛋白的SUMO化水平升高，但是ABA如何调控SUMO化修饰的还不清楚。本项目拟利用生物化学、细胞生物学和遗传学等技术，研究ABA调控NUA蛋白磷酸化的机制，确定其磷酸化位点；探索ABA与NUA调控的SUMO化修饰、mRNA输出的关系；明确NUA在ABA信号通路中的作用，并筛选磷酸化NUA的蛋白激酶，完善ABA信号通路。