Function
An essential component of the GATOR subcomplex GATOR2 which functions as an activator of the amino acid-sensing branch of the TORC1 signaling pathway (PubMed:27166823, PubMed:23723238). The two GATOR subcomplexes, GATOR1 and GATOR2, regulate the TORC1 pathway in order to mediate metabolic homeostasis, female gametogenesis and the response to amino acid limitation and complete starvation (PubMed:27166823, PubMed:23723238, PubMed:25512509). GATOR2 activates the TORC1 signaling pathway through the inhibition of the GATOR1 subcomplex, controlling the switch to cell proliferation growth under nutrient replete conditions and growth during female oocyte development (PubMed:21521741, PubMed:25512509, PubMed:23723238, PubMed:27166823). This component is required for activating TORC1 specifically in germline cells to promote cell growth and maintain the oocyte fate, probably influences the organization and/or function of microtubules within ovarian cysts, and promotes accumulation of another GATOR2 complex member mio in germline and somatic tissues (PubMed:27166823, PubMed:23723238, PubMed:25512509, PubMed:21521741). GATOR1 and GATOR2 act at different stages of oogenesis to regulate TORC1 in order to control meiotic entry and promote oocyte growth and development (PubMed:25512509). After exactly four mitotic cyst divisions, the GATOR1 complex members (Iml1, Nprl2 and Nprl3) down-regulate TORC1 to slow cellular metabolism and promote the mitotic/meiotic transition (PubMed:25512509). At later stages of oogenesis, the mio and Nup44A components of the GATOR2 complex inhibit GATOR1 and thus activate TORC1 to promote meiotic progression, and drive oocyte growth and development (PubMed:21521741, PubMed:25512509). In addition to its role in the regulation of the TORC1 complex, functions independently of TORC1 to prevent the inappropriate accumulation of autolysosomes in germline tissues (PubMed:27166823).
Sequence
MFDVEPIIADHKDVIHDVVFDYYGRRMATCSSDQTVKIWDEDGQGKWNVTSSWKAHSGSIWRVSWAHPEFGQVVATCSFDRTASVWEEVIGEKVSSTNTPTRRWVRRTTLVDSRTSVTDVEFAPKYLGLLLATASADGIIRIYEAPDIMNLSQWPVQHEISNKLPLSCLSWNTSTYMVTQLLAAGSDEAATPTGKVFLFAYSENSRKCVKIDTVNDITDPVTDVAFAPNAGRTFHMLAVASKDLYIVNLRGVTDATDISKLDIQTIKFSEHNCPVWRVCWNMLATMLISTGDDGCVRLWRMNYNRQWRCAAVLKAEGSGPTYEPAPPTPTLATTASATAKFYKKGTIGNQVPWH