E3 ubiquitin-protein ligase (By similarity). Mediates 'Lys-63'-linked polyubiquitination and stabilization of the JUN coactivator RNF187 in response to growth factor signaling via the MEK/ERK pathway, thereby regulating JUN transactivation and cellular proliferation (By similarity). Promotes the TLR4-mediated signaling activation through its E3 ligase domain leading to production of pro-inflammatory cytokines and type I interferon (PubMed:30928727). Also plays a negative role in the regulation of exogenous cytosolic DNA virus-triggered immune response. Mechanistically, enhances the 'Lys-48'-linked ubiquitination of STING1 leading to its proteasome-dependent degradation (PubMed:32126128). 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. Forms homodimers, and heterodimers with GNIP2. Interacts with GYG. Interacts with RNF187 (via C-terminus). Highly expressed in antigen-presenting cells. The B30.2 domain mediates interaction with GYG. The coiled-coil region mediates homodimerization and heterodimerization. Phosphorylated at Ser-106 by RPS6KA5/MSK1, which stimulates the ubiquitin ligase activity. Deletion mutant protects mice from DNA virus infection. Belongs to the TRIM/RBCC family.