Membrane-bound E3 ubiquitin-protein ligase that mediates ubiquitination of target proteins. May function together with E2 ubiquitin-conjugating enzymes UBE2D1/UBCH5A and UBE2D2/UBC4. Mediates ubiquitination of PXN/paxillin,thereby regulating cell motility and localization of PXN/paxillin. Catalyzes ubiquitination of Salmonella type III secreted protein sopA. Mediates the 'Lys-63'-linked polyubiquitination of JKAMP thereby regulating JKAMP function by decreasing its association with components of the proteasome and ERAD; the ubiquitination appears to involve E2 ubiquitin-conjugating enzyme UBE2N. Mediates the 'Lys-48'-linked polyubiquitination of STING1 at 'Lys-150' leading to its proteasomal degradation; the ubiquitination occurs in mitochondria after viral transfection and regulates antiviral responses. Catalyzes ubiquitination and subsequent degradation of ATG4B, thereby inhibiting autophagy. 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 PXN. Interacts with JKAMP. Interacts with STING1; the interaction of endogenous proteins is dependent on viral infection. Predominantly located in the plasma membrane, with some localization occurring within cytoplasmic organelles. Belongs to the RNF5 family.