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 ubiquitinactivating enzymes (E1s), the ubiquitin-conjugating enzymes (E2s) and the ubiquitin-protein ligases (E3s). UBCE7IP4 (Ubiquitin-conjugating enzyme 7- interacting protein 4), also known as RNF144A (RING finger protein 144A), KIAA0161 or RNF144, is a 292 amino acid single-pass membrane protein that contains one RING-type zinc finger and two IBR-type zinc fingers. Functioning as an E3 ubiquitin-protein ligase, UBCE7IP4 accepts ubiquitin (in the form of a thioester) from E2 ubiquitin-conjugating enzymes, such as UBC8 and UBCH7, and transfers that ubiquitin residue to target substrates. Via its RING finger, UBCE7IP4 may play a role in protein-DNA and protein-protein interactions throughout the cell.