General sensor of environmental conditions, such as heat stress, effecting changes through pkaC. Essential for survival to nitrosoative and oxidative stresses. Required for cell cycle control, not only at the onset but also during development (aggregation process and postaggregative development). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Expressed during growth-to-development stages with increase in cell density. Null cells fail to enter development, express low levels of cAMP receptors, are smaller than wild-type cells, are hypersensitive to nitrosoative/oxidative stress, and display slow growth on bacterial lawns. Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MNB/DYRK subfamily.