PUB22 and PUB23 U-box E3 ubiquitin ligases negatively regulate 26S proteasome activity under proteotoxic stress conditions

• 作者: Min Yong Ahn Dong Hye Seo Woo Taek Kim
• 来源期刊: 植物学报（英文版）
• 年，卷（期）: 2022,（3）
• 所属期刊栏目: Breakthrough Report
• 页码范围: 625-631
• 页数: 7页
• 语种: 英文

摘要

The mechanism regulating proteasomal activity under proteotoxic stress conditions remains un-clear. Here, we showed that arsenite-induced proteotoxic stress resulted in upregulation of Ara-bidopsis homologous PUB22 and PUB23 U-box E3 ubiquitin ligases and that pub22pub23 double mutants displayed arsenite-insensitive seed ger-mination and root growth phenotypes. PUB22/PUB23 downregulated 26S proteasome activity by promoting the dissociation of the 19S regulatory particle from the holo-proteasome complex, resulting in intracellular accumulation of UbG76V-GFP, an artificial substrate of the proteasome complex, and insoluble poly-ubiquitinated proteins. These results suggest that PUB22/PUB23 play a critical role in arsenite-induced proteotoxic stress response via negative regulation of 26S proteasome integrity.