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SINAT E3 Ubiquitin Ligases Mediate FREE1 and VPS23A Degradation to Modulate Abscisic Acid Signaling.
- Source :
-
The Plant cell [Plant Cell] 2020 Oct; Vol. 32 (10), pp. 3290-3310. Date of Electronic Publication: 2020 Aug 04. - Publication Year :
- 2020
-
Abstract
- In plants, the ubiquitin-proteasome system, endosomal sorting, and autophagy are essential for protein degradation; however, their interplay remains poorly understood. Here, we show that four Arabidopsis ( Arabidopsis thaliana ) E3 ubiquitin ligases, SEVEN IN ABSENTIA OF ARABIDOPSIS THALIANA 1 (SINAT1), SINAT2, SINAT3, and SINAT4, regulate the stabilities of FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING1 (FREE1) and VACUOLAR PROTEIN SORTING23A (VPS23A), key components of the endosomal sorting complex required for transport-I, to modulate abscisic acid (ABA) signaling. GFP-SINAT1, GFP-SINAT2, and GFP-SINAT4 primarily localized to the endosomal and autophagic vesicles. SINATs controlled FREE1 and VPS23A ubiquitination and proteasomal degradation. SINAT overexpressors showed increased ABA sensitivity, ABA-responsive gene expression, and PYRABACTIN RESISTANCE1-LIKE4 protein levels. Furthermore, the SINAT-FREE1/VPS23A proteins were codegraded by the vacuolar pathway. In particular, during recovery post-ABA exposure, SINATs formed homo- and hetero-oligomers in vivo, which were disrupted by the autophagy machinery. Taken together, our findings reveal a novel mechanism by which the proteasomal and vacuolar turnover systems regulate ABA signaling in plants.<br /> (© 2020 American Society of Plant Biologists. All rights reserved.)
- Subjects :
- Abscisic Acid pharmacology
Arabidopsis drug effects
Arabidopsis genetics
Arabidopsis Proteins genetics
Autophagy
Gene Expression Regulation, Plant
Mass Spectrometry methods
Plants, Genetically Modified
Protein Interaction Maps physiology
Ubiquitin-Protein Ligases genetics
Ubiquitin-Protein Ligases metabolism
Ubiquitination
Vacuoles metabolism
Vesicular Transport Proteins genetics
Abscisic Acid metabolism
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Vesicular Transport Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1532-298X
- Volume :
- 32
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- The Plant cell
- Publication Type :
- Academic Journal
- Accession number :
- 32753431
- Full Text :
- https://doi.org/10.1105/tpc.20.00267