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. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Targeted to cytoplasmic membranes; mainly localizes to lysosomal membrane. A subpopulation localizes to the cell membrane of neurons. Autoubiquitinated in vitro in the presence of UBE2D1 and UBE2E1. Belongs to the Godzilla family.