TRIAD1, also known as ARIH2 (ariadne homolog 2) or ARI2, is a 493 amino acid protein that contains one IBR-type zinc finger and two RING-type zinc fingers and belongs to the ariadne subfamily of RBR proteins. Localized to the nucleus, TRIAD1 interacts with UBE2L3 and is thought to act as an E3 ubiquitin-protein ligase, functioning to accept ubiquitin from E2 ubiquitin-conjugating enzymes and transfer the acquired ubiquitin residue to target substrates. TRIAD1 is subject to post-translational DNA damage-dependent phosphorylation, probably by ATM or ATR. The gene encoding TRIAD1 maps to human chromosome 3, which houses over 1,100 genes, including a chemokine receptor (CKR) gene cluster and a variety of human cancer-related gene loci.
