E3 ubiquitin-protein ligase that mediates ubiquitination of Delta receptors, which act as ligands of Notch proteins. Positively regulates the Delta-mediated Notch signaling by ubiquitinating the intracellular domain of Delta, leading to endocytosis of Delta receptors. Involved in ubiquitination of centriolar satellite CEP131, CEP290 and PCM1 proteins and hence inhibits primary cilium formation in proliferating cells. Mediates 'Lys-63'-linked polyubiquitination of TBK1, which probably participates in kinase activation (By similarity). Probably mediates ubiquitination and subsequent proteasomal degradation of DAPK1, thereby antagonizing anti-apoptotic effects of DAPK1 to promote TNF-induced apoptosis. 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 CEP131 and PCM1. Displaced from centriolar satellites in response to cellular stress, such as ultraviolet light (UV) radiation or heat shock (By similarity). Localizes to the plasma membrane. Detected in all tissues tested. Present in embryo, embryonic stem cells, bladder, skeletal muscle, bladder, uterus, testis, stomach, colon, ileum, trachea, lung, aorta, kidney, spleen, liver and vas deferens (at protein level). Highly expressed in testis. Highly expressed both in embryos and adult tissues. In 9.5 dpc and 10.5 dpc embryos, it is expressed in the tail bud, limb buds and somites. Expressed in the same pattern than MIB2 in the skin and intestine at postnatal day 1 (P1) and in the hair follicle in the skin in the adult. Ubiquitinated; this modification is inhibited in response to cellular stress, such as ultraviolet light (UV) radiation or heat shock (By similarity). Ubiquitinated; possibly via autoubiquitination. Chimeric cDNA. Contaminating sequence. Sequence of unknown origin in the C-terminal part.