Involved in the final steps of cytoplasmic maturation of the 40S ribosomal subunit (By similarity). Despite the protein kinase domain is proposed to act predominantly as an ATPase (By similarity). The catalytic activity regulates its dynamic association with the 40S subunit (By similarity). Plays a role in oogenesis by regulating germ cell proliferation, progression through diplotene and diakinesis stages and oocyte maturation (PubMed:24929033, PubMed:25688864). Regulates germline development probably by regulating the phosphorylation of mpk-1 (PubMed:25688864). Involved in larval development (PubMed:24929033, PubMed:25688864). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Expressed in vulva and uterine cells, uterine seam cells (utse), spermatheca and in the nervous system including chemosensory neurons in the head, nerve ring neurons (RID/RIF), inhibitory motor neurons (DA/DD/VA/VD), mechanosensory neurons (ALML/PLML) and tail sensory neurons (DVA//PDA) (PubMed:24929033, PubMed:25688864). Also expressed in intestine and pharynx (procorpus) and rectal valve and gland (PubMed:25688864). Expressed in the nervous system at all larval stages. Expressed in somatic gonad and in the ventral nerve cord at L2 larval stage. Expressed in somatic gonad, in ventral uterine (VU/AC) cells and in the committed anchor cell at L3 larval stage. Expressed in vulF cells of the vulva, uterine cells and in uterine seam cells (utse) at L4 larval stage. RNAi-mediated knockdown causes early larval arrest. In adults, results in sterility. Causes malformations of the gonad arms (empty or misshaped) and a protruding vulva (PubMed:24929033). Abnormal germline development characterized by a decrease in the number of proliferating germ cells in the mitotic and transition zones. At the diplotene stage, cells are disorganized and have enlarged nuclei. Oocytes have abnormal shape and large DNA aggregates next to abnormally located sperm. In addition, 50 percent of cells fails to decrease mpk-1 phosphorylation upon pachytene stage exit (PubMed:24929033, PubMed:25688864). RNAi-mediated knockdown in a let-60 n1046 mutant background suppresses the formation of multivulva (PubMed:24929033). Belongs to the protein kinase superfamily. RIO-type Ser/Thr kinase family.