function: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.,induction:Down-regulated in many primary skin melanomas. Treatment with a demethylating agent, 5'-aza-2-deoxycytidine, restores expression, suggesting that down-regulation is the result of methylation of the gene.,pathway:Protein modification; protein ubiquitination.,PTM:Ubiquitinated. Possibly via autoubiquitination.,similarity:Contains 1 ZZ-type zinc finger.,similarity:Contains 2 MIB/HERC2 domains.,similarity:Contains 2 RING-type zinc fingers.,similarity:Contains 9 ANK repeats.,subcellular location:Colocalizes with endosomal compartments.,subunit:Interacts with actin monomer.,tissue specificity:Expressed in skeletal muscle, and to a lesser extent in heart, brain and kidney.,