E3 ubiquitin-protein ligase that acts as a regulator of the TORC1 signaling pathway (, ). Positively regulates the TORC1 signaling pathway independently of arginine levels: acts by catalyzing 'Lys-29'-polyubiquitination and degradation of CASTOR1, releasing the GATOR2 complex from CASTOR1 . Also negatively regulates the TORC1 signaling pathway in response to leucine deprivation: acts by mediating 'Lys-63'-linked polyubiquitination of SESN2, promoting SESN2-interaction with the GATOR2 complex . Also involved in protein trafficking and localization (  ). Acts as a regulator of synaptic transmission by mediating ubiquitination and degradation of AMPAR receptor GluA2/GRIA2 (, ). Does not catalyze ubiquitination of GluA1/GRIA1 . Also acts as a regulator of the recycling endosome pathway by mediating ubiquitination of VAMP3 . Regulates lysosome positioning by catalyzing ubiquitination and degradation of ARL8B . Plays a role in growth regulation involved in G1/S transition by mediating, possibly by mediating ubiquitination of SLC22A18 . Acts with a limited set of E2 enzymes, such as UBE2D1 and UBE2N .
Subcellular locations: Lysosome membrane, Endosome membrane, Endomembrane system, Cell membrane
Targeted to cytoplasmic membranes; mainly localizes to lysosomal membrane (, ). A subpopulation localizes to the cell membrane of neurons .
Subcellular locations: Lysosome membrane
Subcellular locations: Cytoplasm, Cytosol
Widely expressed . Strongly expressed in the kidney, pancreas, testis and liver (at protein level) (, ).