Serine/threonine-protein kinase which regulates mRNA translation (PubMed:17266680). Negatively regulates lifespan and resistance to starvation, oxidative stress, protein aggregation and P.aeruginosa-mediated infection (PubMed:17266680, PubMed:23879233, PubMed:24332851). May regulate these processes by preventing the activation of transcription factor hif-1 (PubMed:23879233). Required, probably downstream of let-363/TOR, for the establishment of the proper number of germline progenitors by promoting cell cycle progression and preventing differentiation during larval development. Regulates germ cell size (PubMed:22278922). In addition required for sperm production and embryo viability (PubMed:17266680, PubMed:22278922). Involved in axon regeneration of PLM and ALM neurons by inhibiting growth cone formation early after axotomy and later by inhibiting axon extension. Functions in axon regeneration and lifespan probably by preventing aak-2/AMPK activation (PubMed:24332851, PubMed:24431434). Negatively regulates autophagy (PubMed:22560223). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Enriched in the synaptic branch of PLM neurons. May be phosphorylated on Thr-404 by let-363/TOR. RNAi-mediated knockdown causes an increased lifespan and resistance to starvation, slower growth and a decrease in brood size (PubMed:17266680). Causes a decrease in the number of germline progenitors (PubMed:22278922). RNAi-mediated knockdown in adults causes increase in lgg-1 positive autophagic vesicles (PubMed:22560223). RNAi-mediated knockdown in a daf-2 e1370 mutant background results in daf-16-mediated up-regulation of stdh-1 reporter expression in the intestine and a synergistic increase in lifespan. RNAi-mediated knockdown in germ line, hypodermis and to a lesser extent in intestine and daf-2 e1370 mutant background causes a synergistic increase in lifespan (PubMed:24332851). Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. S6 kinase subfamily.