Importation of chloroplast proteins under heat stress is facilitated by their SUMO conjugations
Importation of chloroplast proteins under heat stress is facilitated by their SUMO conjugations
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SUMO 结合促进热应激下叶绿体蛋白的输入
DOI：
10.1111/nph.18121
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发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Chengwei Yang
中科院分区：
文献类型：
--
作者：
Xiao‐Ting Zheng;Caijuan Wang;Wenxiong Lin;Chufang Lin;Danlu Han;Qi Xie;Jianbin Lai;Chengwei Yang
叶绿体对热胁迫（HS）非常敏感。SUMO化是一种关键的翻译后修饰，保守地参与HS反应。本研究利用生物信息学、生物化学和细胞生物学分析方法，检测了拟南芥核编码叶绿体蛋白SUMO化状态及其对叶绿体SUMO化亚细胞定位的影响。以光系统II的一个亚基PSBR为例，详细研究了其功能机制。在对核编码的叶绿体蛋白进行全局SUMO化位点预测后，生化数据显示，大多数选定的候选蛋白都被细胞质中的SUMO 3修饰。这些SUMO化靶标在长期HS下的叶绿体定位部分由SUMO连接酶AtSIZ1维持。HS诱导的PSBR上的SUMO化有助于维持其叶绿体定位，这取决于其与磷酸化相关的叶绿体输入效率。互补分析结果表明SUMO化是PSBR在高温胁迫下发挥生理功能所必需的。本研究阐明了SUMO化在高温胁迫下维持叶绿体蛋白质输入的一般调控机制，为进一步研究植物细胞器在高温胁迫下的蛋白质修饰提供了线索。
Chloroplasts are hypersensitive to heat stress (HS). SUMOylation, a critical post‐translational modification, is conservatively involved in HS responses. However, the functional connection between SUMOylation and chloroplasts under HS remains to be studied.The bioinformatics, biochemistry, and cell biology analyses were used to detect the SUMOylation statuses of Arabidopsis nuclear‐encoded chloroplast proteins and the effect of SUMOylation on subcellular localization of these proteins under HS. PSBR, a subunit of photosystem II, was used as an example for a detailed investigation of functional mechanisms.After a global SUMOylation site prediction of nuclear‐encoded chloroplast proteins, biochemical data showed that most of the selected candidates are modified by SUMO3 in the cytoplasm. The chloroplast localization of these SUMOylation targets under long‐term HS is partially maintained by the SUMO ligase AtSIZ1. The HS‐induced SUMOylation on PSBR contributes to the maintenance of its chloroplast localization, which is dependent on its chloroplast importation efficiency correlated to phosphorylation. The complementation analysis provided evidence that SUMOylation is essential for the physiological function of PSBR under HS.Our study illustrated a general regulatory mechanism of SUMOylation in maintaining the chloroplast protein importation during HS and provided hints for further investigation on protein modifications associated with plant organelles under stress conditions.