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Ligand-triggered de-repression of Arabidopsisheterotrimeric G proteins coupled to immune receptor kinases
- Source :
- Cell Research; May 2018, Vol. 28 Issue: 5 p529-543, 15p
- Publication Year :
- 2018
-
Abstract
- Arabidopsisheterotrimeric G proteins regulate diverse processes by coupling to single-transmembrane receptors. One such receptor is the FLS2 receptor kinase, which perceives bacterial flagellin epitope flg22 to activate immunity through a class of cytoplasmic kinases called BIK1/PBLs. Unlike animal and fungal heterotrimeric G proteins that are activated by a ligand-induced guanine nucleotide exchange activity of seven-transmembrane G protein-coupled receptors (GPCRs), plant heterotrimeric G proteins are self-activating. How plant receptors regulate heterotrimeric G proteins in response to external ligands remains unknown. Here we show that RGS1, a GTPase accelerating protein, maintains ArabidopsisG proteins in an inactive state in complex with FLS2. Activation of FLS2 by flg22 induces a BIK1/PBL-mediated phosphorylation of RGS1 at Ser428 and Ser431 and that promotes RGS1 dissociation from the FLS2-G protein complex. This relieves G proteins from the RGS1-mediated repression and enables positive regulation of immune signaling. We additionally show that RGS1 is similarly regulated by multiple immune receptors. Our results uncover ligand-induced de-repression as a mechanism for G protein signaling in plants that is distinct from previously reported mechanism underlying the activation of heterotrimeric G proteins in other systems.
Details
- Language :
- English
- ISSN :
- 10010602 and 17487838
- Volume :
- 28
- Issue :
- 5
- Database :
- Supplemental Index
- Journal :
- Cell Research
- Publication Type :
- Periodical
- Accession number :
- ejs45097577
- Full Text :
- https://doi.org/10.1038/s41422-018-0027-5