Ubiquitination is an important mechanism through which three classes of enzymes act in concert to target short-lived or abnormal proteins for destruction. The three classes of enzymes involved in ubiquitination are the ubiquitin-activating enzymes (E1s), the ubiquitin-conjugating enzymes (E2s) and the ubiquitin-protein ligases (E3s). DZIP3 (DAZ interacting protein 3, zinc finger), also known as UURF2 or hRUL138, is a 1,208 amino acid protein that localizes to the cytoplasm and contains one RING-type zinc finger. Expressed in a variety of tissues with highest expression in heart, skeletal muscle and kidney, DZIP3 functions as an E3 ubiquitin-protein ligase that accepts ubiquitin from an E2 ubiquitin-conjugating enzyme, thereby playing a role in signaling events throughout the cell. Multiple isoforms of DZIP3 exist due to alternative splicing events.