1. PUB22 and PUB23 U-box E3 ubiquitin ligases negatively regulate 26S proteasome activity under proteotoxic stress conditions.
- Author
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Ahn MY, Seo DH, and Kim WT
- Subjects
- Arabidopsis Proteins genetics, Ubiquitin-Protein Ligases genetics, Arabidopsis metabolism, Arabidopsis Proteins metabolism, Proteasome Endopeptidase Complex metabolism, Ubiquitin-Protein Ligases metabolism
- Abstract
The mechanism regulating proteasomal activity under proteotoxic stress conditions remains unclear. Here, we showed that arsenite-induced proteotoxic stress resulted in upregulation of Arabidopsis homologous PUB22 and PUB23 U-box E3 ubiquitin ligases and that pub22pub23 double mutants displayed arsenite-insensitive seed germination 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 Ub
G76V -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., (© 2021 Institute of Botany, Chinese Academy of Sciences.)- Published
- 2022
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