E3 ubiquitin-protein ligase that acts as a negative regulator of mTORC1 signaling by mediating ubiquitination of RagA/RRAGA and RHEB (, ). Catalyzes 'Lys-63'-linked polyubiquitination of RagA/RRAGA in response to amino acid starvation, thereby regulating mTORC1 signaling . Also mediates monoubiquitination of RHEB, promoting its association with the TSC-TBC complex and subsequent inhibition . Also mediates 'Lys-48'-linked polyubiquitination of target proteins and their subsequent targeting to the proteasome for degradation . Induces apoptosis when overexpressed .
Subcellular locations: Lysosome membrane
Widely expressed.