E3 ubiquitin-protein ligase mediating 'Lys-63'-linked polyubiquitination of RRAGA in response to amino acid starvation. Thereby, regulates mTORC1 signaling and plays a role in the cellular response to amino acid availability. Also mediates 'Lys-48'-linked polyubiquitination of target proteins and their subsequent targeting to the proteasome for degradation. Induces apoptosis when overexpressed.