1. Cytosolic ABA Receptor Kinases phosphorylate the D6 PROTEIN KINASE leading to its stabilization which promotes Arabidopsis growth.
- Author
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He J, Li X, Yu Q, Peng L, Chen L, Liu J, Wang J, Li X, and Yang Y
- Subjects
- Phosphorylation, Indoleacetic Acids metabolism, Protein Serine-Threonine Kinases metabolism, Protein Serine-Threonine Kinases genetics, Cytosol metabolism, Abscisic Acid metabolism, Gene Expression Regulation, Plant, Protein Kinases metabolism, Protein Kinases genetics, Proteasome Endopeptidase Complex metabolism, Plants, Genetically Modified, Arabidopsis growth & development, Arabidopsis genetics, Arabidopsis metabolism, Arabidopsis enzymology, Arabidopsis Proteins metabolism, Arabidopsis Proteins genetics
- Abstract
The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN-FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss-of-function of CARK3 in overexpressing GFP-D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell-free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin-mediated plant growth and development., (© 2024 John Wiley & Sons Ltd.)
- Published
- 2024
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