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  2. The adaptor protein AP-3β disassembles heat-induced stress granules via 19S regulatory particle in Arabidopsis

The adaptor protein AP-3β disassembles heat-induced stress granules via 19S regulatory particle in Arabidopsis

  • Nat Commun. 2025 Feb 27;16(1):2039. doi: 10.1038/s41467-025-57306-7.
Lei Pang 1 Yuanzhi Huang 1 Yilin He 1 Dong Jiang 1 Ruixi Li 2
Affiliations

Affiliations

  • 1 Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
  • 2 Shenzhen Key Laboratory of Plant Genetic Engineering and Molecular Design, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China. lirx@sustech.edu.cn.
Abstract

To survive under adverse conditions, Plants form stress granules (SGs) to temporally store mRNA and halt translation as a primary response. Dysregulation in SG disassembly can have detrimental effects on plant survival after stress release, yet the underlying mechanism remains poorly understood. Using Arabidopsis as a model system, we demonstrate that the β subunit of adaptor protein (AP) -3 complex (AP-3β) interacts with the SG core RNA-binding proteins Tudor staphylococcal nuclease 1/2 (TSN1/2) both in vitro and in vivo. We also show that AP-3β is rapidly recruited to SGs upon heat induction and plays a key role in disassembling SGs during stress recovery. Genetic evidences support that AP-3β serves as an adaptor to recruit the 19S regulatory particle (RP) of the Proteasome to SGs. Notably, the 19S RP promotes SG disassembly through RP-associated deubiquitylation, independent of its proteolytic activity. This deubiquitylation process of SG components is crucial for translation reinitiation and growth recovery after heat release. Our findings uncover a previously unexplored role of the 19S RP in regulating SG disassembly and highlights the importance of endomembrane proteins in supporting RNA granule dynamics in Plants.

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