This family represents the C-terminal region of the E3 ubiquitin ligase RNF152 containing the hydrophobic transmembrane domain, responsible for the lysosomal localisation of the protein as well as its ubiquitination activity. This protein polyubiquitinates several proteins and itself, which leads to proteasome degradation. It has been shown that RNF152 has also pro-apoptotic activity, dependent on its RING finger and transmembrane domains [1]. In addition, the transmembrane domain of RNF152 is necessary for negative regulation of the mTORC1 pathway in an amino-acid-sensitive manner, as it mediates RNF152-RagA interaction and RagA ubiquitination [2].

1: RNF152, a novel lysosome localized E3 ligase with pro-apoptotic activities. Zhang S, Wu W, Wu Y, Zheng J, Suo T, Tang H, Tang J; Protein Cell. 2010;1:656-663. PMID:21203937

2: The ubiquitination of rag A GTPase by RNF152 negatively regulates mTORC1 activation. Deng L, Jiang C, Chen L, Jin J, Wei J, Zhao L, Chen M, Pan W, Xu Y, Chu H, Wang X, Ge X, Li D, Liao L, Liu M, Li L, Wang P; Mol Cell. 2015;58:804-818. PMID:25936802