The SNF1/AMPK/SnRK1 kinases are evolutionary conserved kinases involved in yeast, mammals and plants in the control of energy balance. This heterotrimeric enzyme is composed of one alpha-type catalytic subunit and two gamma- and beta-type regulatory subunits. In yeast it has been proposed that the beta-type subunits regulate both the localization of the kinase complexes within the cell and the interaction of the kinase with its targets. In the present work, we demonstrate that the three beta-type subunits of Arabidopsis thaliana (AKINbeta1, beta2 and beta3) restore the growth phenotype of the yeast sip1Deltasip2Deltagal83Delta triple mutant thus suggesting the conservation of an ancestral function. Expression analyses, using AKINbeta promoter::GUS transgenic lines, reveal different and specific patterns of expression for each subunit according to organs, developmental stages and environmental conditions. Finally our results show that the beta-type subunits are involved in the specificity of interaction of the kinase with the cytosolic nitrate reductase (NR). Together with previous cell-free phosphorylation data, they strongly support the proposal that NR is a real target of SnRK1 in the physiological context. Altogether our data suggest the conservation of (an) ancestral basic function(s) together with specialized functions for each beta-type subunit in plants.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|