Nucleocytoplasmic Trafficking of the Arabidopsis WD40 Repeat Protein XIW1 Regulates ABI5 Stability and Abscisic Acid Responses  

作　　者：Xuezhong XU Wang Wan Guobin Jiang Yue Xi Haijian Huang Jiajia Cai Yanan Chang Cheng-Guo Duan Satendra KMangrauthia Xinxiang Peng Jian-Kang Zhu Guohui Zhu 

机构地区：[1]College of Life Sciences,South China Agricultural University,Guangzhou 510642,China [2]Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences,Chinese Academy of Sciences,Shanghai 201602,China [3]Biotechnology Section,Indian Institute of Rice Research,Hyderabad 500030,India [4]State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,South China Agricultural University,Guangzhou 510642,China [5]Department of Horticulture and Landscape Architecture,Purdue University,West Lafayette,IN 47907,USA [6]Guangdong Provincial Key Laboratory of Protein Function and Regulation in

出　　处：《Molecular Plant》2019年第12期1598-1611,共14页分子植物（英文版）

基　　金：This work was supported by grants from the National Natural Science Foundation of China(31570250);the Science and Technology Project of Guangzhou City,China(201607020006,201804010377);the Natural Science Foundation of Guangdong Province,China(2015A030313410,2017A030313100).

摘　　要：WD40 repeat-containing proteins(WD40 proteins)serve as versatile scaffolds for protein-protein interac-tions,modulating a variety of cellular processes such as plant stress and hormone responses.Here we report the identification of a WD40 protein,XIW1(for XPO1-interacting WD40 protein 1),which positively regulates the abscisic acid(ABA)response in Arabidopsis.XIW1 is located in the cytoplasm and nucleus.We found that it interacts with the nuclear transport receptor XPO1 and is exported by XPO1 from the nucleus.Mutation of XIW1 reduces the induction of ABA-responsive genes and the accumulation of ABA Insensitive 5(ABI5),causing mutant plants with ABA-insensitive phenotypes during seed germination and seedling growth,and decreased drought stress resistance.ABA treatment upregulates the expression of XIW1,and both ABA and abiotic stresses promote XIW1 accumulation in the nucleus,where it interacts with ABI5.Loss of XIW1 function results in rapid proteasomal degradation of ABI5.Taken together,these findings suggest that XIW1 is a nucleocytoplasmic shuttling protein and plays a positive role in ABA responses by interacting with and maintaining the stability of ABI5 in the nucleus.

关 键 词：WD40 protein ABA signaling nuclear EXPORT ABI5 STABILITY XPO1 

分 类 号：Q94[生物学—植物学]