Serine/threonine-protein kinase involved in the postembryonic regulation of body size, mainly through control of cell growth. In particular, controls the volume of intestine, muscles and hypodermis. In addition, regulates growth, intestinal granule distribution, lifespan and number of offspring. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Expressed in intestine with a stronger expression in the four most anterior cells, muscles, excretory cell, pharynx and, to a lesser extent, in hypodermis. RNAi-mediated knockdown results in an approximately 50 percent reduction in number of offspring. Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.