The impact of Arabidopsis thaliana SNF1‐related‐kinase 1 (SnRK1)‐activating kinase 1 (SnAK1) and SnAK2 on SnRK1 phosphorylation status: characterization of a SnAK double mutant

• DOI: 10.1111/tpj.13445
• Publication Date: 2016-12-10T21:06:11Z
• Authors: Nathalie Glab; Céline Oury; Thomas Guérinier; Séverine Domenichini; Pierre Crozet; Martine Thomas; Jean Vidal; Michael Hodges
• Keywords: 580; 0301 basic medicine; 570; Arabidopsis thaliana; phosphorylation; Arabidopsis Proteins; [SDV]Life Sciences [q-bio]; Arabidopsis; SnRK1-activating kinase; Protein Serine-Threonine Kinases; Plants, Genetically Modified; Open Reading Frames; 03 medical and health sciences; Gene Expression Regulation, Plant; SNF1-related protein kinase-1; double mutant; Phosphorylation; signalling cascade; Signal Transduction

Arabidopsis thaliana SNF1-related-kinase 1 (SnRK1)-activating kinase (AtSnAK1) and AtSnAK2 have been shown to phosphorylate in vitro activate the energy signalling integrator, SnRK1. To clarify this cascade planta, a genetic- molecular-based approach was developed. Homozygous single AtSnAK1 T-DNA insertional mutants did not display an apparent phenotype. Crossing of allow isolation double-mutant plants, whereas self-pollinating S1-/- S2+/- sesquimutant specifically gave approximatively 22% individuals their offspring that, when rescued on sugar-supplemented media vitro, were be double mutants. Interestingly, obtained case other sesquimutant, S1+/- S2-/-. Although reduced size, mutant had capacity produce flowers, but seeds. Immunological characterization established T-loop SnRK1 catalytic subunit non-phosphorylated absence both SnAKs. When complemented with DNA construct containing open reading frame driven by its own promoter, normal phenotype restored. Therefore, wild-type plant growth development is dependent presence SnAK vivo, correlated phosphorylation. These data show that SnAKs are kinases phosphorylating SnRK1, thereby they contribute planta.