TNFAIP3

Tumor necrosis factor, alpha-induced protein 3 or A20 is a protein that in humans is encoded by the TNFAIP3 gene.

This gene was identified as a gene whose expression is rapidly induced by the tumor necrosis factor (TNF). The protein encoded by this gene is a zinc finger protein and a deubiquitinating enzyme, and has been shown to inhibit NF-kappa B activation as well as TNF-mediated apoptosis. The A20 protein is ancient, and protein homolog can be found as far back as cnidaria (corals, jellyfish, anemones) with a conserved protein domain composition. Using knockout mouse models of TNFAIP3 and its transcriptional repressor (i.e. KCHIP3), TNFAIP3 has been shown to be critical for limiting inflammation by terminating endotoxin- and TNF-induced NF-kappa B responses. In brief, deubiquitinase function of TNFAIP3 was shown to remove ubiquitin chains from VE-cadherin to prevent loss of VE-cadherin at the endothelial adherens junctions.