E3 ubiquitin-protein ligase that participates in multiple biological processes including cell death, glucose metabolism, and in particular, the innate immune response (By similarity) (PubMed:32562145). Mediates 'Lys-63'-linked polyubiquitination of TRAF3 thereby promoting type I interferon production via DDX58/RIG-I signaling pathway. Can also catalyze 'Lys-48'-linked polyubiquitination and proteasomal degradation of viral proteins such as influenza virus PB2. Acts as a negative feedback regulator of TLR7- and TLR9-triggered signaling. Mechanistically, promotes the 'Lys-48'-linked ubiquitination of IRF7 and induces its degradation via a proteasome-dependent pathway. Reduces FGFR1-dependent tyrosine phosphorylation of PKM, inhibiting PKM-dependent lactate production, glucose metabolism, and cell growth (By similarity). 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 PKM isoform M2, but not isoform M1; this interaction may compete with that between PKM and FGFR1, and hence reduces FGFR1-dependent tyrosine phosphorylation of PKM. Interacts with IRF7; this interaction promotes IRF7 proteasomal degradation. Interacts with TRAF3; this interaction promotes TRAF3 activation. Found predominantly in cytoplasm with a granular distribution. Found in punctuate nuclear bodies in transfected COS and HeLa cells. Widely expressed. Highly expressed in brain, heart, kidney, spleen, skeletal muscle, lung and thymus. Lower expression found in stomach, large intestine and bone marrow. At 10.5 dpc expression was detected in branchial arches 1 and 2 and the fronto-nasal process, limb buds, spinal cord, and dorsal root ganglia. At 12.0 dpc expression was detected primarily in the limbs and transiently in the developing eye. By 13.5 dpc, expression in the limb was restricted to thetelencephalic region of forebrain. Induced by macrophage colony-stimulating factor in murine peritoneal and bone marrow macrophages. The RING finger domain and the coiled-coil region are required for the apoptosis-inducing activity. Deletion mutants are more sensitive to viral infections with a dramatically increased viral load. Belongs to the TRIM/RBCC family.