Phosphorylates yap-1 which may negatively regulate yap-1 nuclear localization (PubMed:23396260). Plays an essential role in larval development (PubMed:19737560, PubMed:19605499). Regulates growth, the formation of gut granules, lifespan and cell and body sizes probably in synergy with the TGF-beta sma/mab pathway (PubMed:19737560). Does not appear to regulate apoptosis and proliferation (PubMed:19605499). In addition, may synergize with the TGF-beta daf-7 dauer pathway to regulate entry into the dauer stage (PubMed:19737560). Maintains the cellular integrity of intestinal cells by regulating the localization of apical actin and junctional proteins (PubMed:19605499). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts (via N-terminus) with yap-1 (via WW domain). In epithelial cells, localized near the plasma membrane. In intestinal cells, localized in the subapical membrane region (PubMed:19605499, PubMed:19737560). Membrane localization starts in the late embryo (PubMed:19605499). Expressed in muscles and epithelial tissues including pharynx, intestine and hypodermis (PubMed:19605499). Expressed in vulval and spermathecal seam cells (PubMed:19737560). Expressed at the embryonic comma stage and during all the larval stages and in adults. RNAi-mediated knockdown results in larval lethality in 50 percent of the animals (PubMed:19737560, PubMed:19605499). Surviving knockdown animals have several defects including a slower growth and a partial distortion of the pharynx. In surviving L3 animals seam cells are 30 percent smaller (PubMed:19737560). Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family.