Activates SnRK1.1/KIN10 and SnRK1.2/KIN11 by phosphorylation of their activation-loop 'Thr-198' and 'Thr-176', respectively. Required for the regulation by SnRK1 kinases of the transcription of a large set of genes, the modification the activity of metabolic enzymes, and the control of various nutrient-responsive cellular developmental processes