Predominantly involved during the aggregation to control cell polarity and chemotaxis. Phosphorylates talB, gefN, gefS, PI4P 5-kinase and gacQ. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Preferentially expressed during growth and aggregation. Cells exhibit aggregation-stage defects, with the aggregates that form producing normal fruiting bodies. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. RAC subfamily.