E3 ubiquitin-protein ligase that mediates E2-dependent, 'Lys-48'- and/or 'Lys-63'-linked polyubiquitination of substrates and may play a role in diverse biological processes. Through their polyubiquitination, may play a role in the endosomal trafficking and degradation of membrane receptors including EGFR, FLT3, MET and CXCR4. 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. Interacts with RAB7A. Interacts with EGFR and FLT3. The GTP-bound form of RAB7A recruits RNF115 from the cytosol onto late endosomes/lysosomes. Expressed at extremely low levels in normal breast, prostate, lung, colon. Higher levels of expression are detected in heart, skeletal muscle, testis as well as in breast and prostate cancer cells. RING-type zinc finger-dependent and E2-dependent autoubiquitination.