Nucleocytoplasmic Trafficking of the Arabidopsis WD40 Repeat Protein XIW1 Regulates ABI5 Stability and Abscisic Acid Responses
Nucleocytoplasmic Trafficking of the Arabidopsis WD40 Repeat Protein XIW1 Regulates ABI5 Stability and Abscisic Acid Responses
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拟南芥 WD40 重复蛋白 XIW1 的核细胞质运输调节 ABI5 稳定性和脱落酸反应
DOI：
10.1016/j.molp.2019.07.001
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发表时间：
2019
期刊：
影响因子：
27.5
通讯作者：
Zhu Guohui
中科院分区：
文献类型：
--
作者：
Xu Xuezhong;Wan Wang;Jiang Guobin;Xi Yue;Huang Haijian;Cai Jiajia;Chang Yanan;Duan Cheng-Guo;Mangrauthia Satendra K.;Peng Xinxiang;Zhu Jian-Kang;Zhu Guohui
含有WD40重复序列的蛋白（WD40蛋白）作为多种蛋白相互作用的支架，调节多种细胞过程，如植物胁迫和激素反应。在这里，我们报道了一个WD40蛋白，XIW1（与xpo1相互作用的WD40蛋白1）的鉴定，该蛋白在拟南芥中正调控脱落酸（ABA）反应。XIW1位于细胞质和细胞核中。我们发现它与核转运受体XPO1相互作用，并由XPO1从细胞核输出。xiw1的突变减少了ABA响应基因的诱导和ABA不敏感5 （ABA Insensitive 5, ABI5）的积累，导致突变植株在种子萌发和幼苗生长过程中出现ABA不敏感表型，抗旱性下降。ABA处理上调了XIW1的表达，ABA和非生物胁迫都促进了XIW1在细胞核中的积累，并与ABI5相互作用。xiw1功能的丧失导致ABI5的蛋白酶体快速降解。综上所述，这些发现表明，XIW1是一种核胞质穿梭蛋白，通过与细胞核内ABI5相互作用并维持其稳定性，在ABA应答中发挥积极作用。
WD40 repeat-containing proteins (WD40 proteins) serve as versatile scaffolds for protein–protein interactions, 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 inArabidopsis. 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 ofXIW1reduces 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 ofXIW1, and both ABA and abiotic stresses promote XIW1 accumulation in the nucleus, where it interacts with ABI5. Loss ofXIW1function 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.