Involved in the control of sexual development and cell growth under stressed conditions. Phosphorylates AGC kinase gad8 at 'Thr-387', activating gad8 kinase activity and promoting sexual development (PubMed:12805221). Phosphorylates AGC kinase psk1 at 'Ser-248', activating psk1 kinase activity and promoting phosphorylation of ribosomal protein S6 (PubMed:22976295). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] The PIF-pocket is a small lobe in the catalytic domain required by the enzyme for the binding to the hydrophobic motif of its substrates. It is an allosteric regulatory site that can accommodate small compounds acting as allosteric inhibitors. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. PDPK1 subfamily.