Coordinates organism morphology with cellular differentiation during development. Negative regulator of sporulation, synchronizing encapsulation with culmination. May have an additional function in prestalk cells. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Expressed at constant levels during growth and throughout development. Uniformly expressed throughout the prespore and the prestalk regions at the finger stage as well as during culmination. Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family.