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Arabidopsis group C Raf-like protein kinases negatively regulate abscisic acid signaling and are direct substrates of SnRK2.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Jul 27; Vol. 118 (30). - Publication Year :
- 2021
-
Abstract
- The phytohormone abscisic acid (ABA) plays a major role in abiotic stress responses in plants, and subclass III SNF1-related protein kinase 2 (SnRK2) kinases mediate ABA signaling. In this study, we identified Raf36, a group C Raf-like protein kinase in Arabidopsis , as a protein that interacts with multiple SnRK2s. A series of reverse genetic and biochemical analyses revealed that 1) Raf36 negatively regulates ABA responses during postgermination growth, 2) the N terminus of Raf36 is directly phosphorylated by SnRK2s, and 3) Raf36 degradation is enhanced in response to ABA. In addition, Raf22, another C-type Raf-like kinase, functions partially redundantly with Raf36 to regulate ABA responses. A comparative phosphoproteomic analysis of ABA-induced responses of wild-type and raf22raf36-1 plants identified proteins that are phosphorylated downstream of Raf36 and Raf22 in planta. Together, these results support a model in which Raf36/Raf22 function mainly under optimal conditions to suppress ABA responses, whereas in response to ABA, the SnRK2 module promotes Raf36 degradation as a means of alleviating Raf36-dependent inhibition and allowing for heightened ABA signaling to occur.<br />Competing Interests: The authors declare no competing interest.<br /> (Copyright © 2021 the Author(s). Published by PNAS.)
- Subjects :
- Arabidopsis genetics
Arabidopsis growth & development
Arabidopsis Proteins genetics
Phosphorylation
Plant Growth Regulators pharmacology
Protein Serine-Threonine Kinases genetics
Protein Serine-Threonine Kinases metabolism
Signal Transduction
Abscisic Acid pharmacology
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Gene Expression Regulation, Plant drug effects
Stress, Physiological
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 118
- Issue :
- 30
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 34282011
- Full Text :
- https://doi.org/10.1073/pnas.2100073118