The function of RNF152 (ring finger protein 152, ENSG00000176641) is as follows. E3 ubiquitin-protein ligase that acts as a negative regulator of mTORC1 signaling by mediating ubiquitination of RagA/RRAGA and RHEB (PubMed:25936802, PubMed:30514904). Catalyzes 'Lys-63'-linked polyubiquitination of RagA/RRAGA in response to amino acid starvation, thereby regulating mTORC1 signaling (PubMed:25936802). Also mediates monoubiquitination of RHEB, promoting its association with the TSC-TBC complex and subsequent inhibition (PubMed:30514904). Also mediates 'Lys-48'-linked polyubiquitination of target proteins and their subsequent targeting to the proteasome for degradation (PubMed:21203937). Induces apoptosis when overexpressed (PubMed:21203937). {ECO:0000269|PubMed:21203937, ECO:0000269|PubMed:25936802, ECO:0000269|PubMed:30514904}.