Protein kinase that is part of growth control pathway which is at least partially redundant with the cAMP pathway. Regulates both BCY1 phosphorylation and MPK1 activity (PubMed:20702584). Regulates ribosome biogenesis, translation initiation, and entry into stationary phase in a TORC1-dependent manner (PubMed:17560372). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by cAMP. Phosphorylated by TORC1 in nutrient-replete conditions and during mechanical stress. Sensitive to high hydrostatic pressure (mechanical stress); simultaneous disruption of RRD1 exacerbates the effect. Present with 3850 molecules/cell in log phase SD medium. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. cAMP subfamily. It is uncertain whether Met-1 or Met-2 is the initiator.