Tumor necrosis factor alpha-induced protein 3 (A20) (TNFAIP3)

Tumor necrosis factor alpha-induced protein 3 (TNFAIP3), widely known as A20, is a critical zinc-finger protein that serves as a primary negative regulator of the NF-κB signaling pathway (UniProt P21583). In dendritic cells (DCs), A20 plays a pivotal role in maintaining immune tolerance by restricting the maturation and pro-inflammatory cytokine production of these cells in response to Toll-like receptor (TLR) ligands (PubMed: 21163940). By functioning as a dual ubiquitin-editing enzyme, A20 removes K63-linked ubiquitin chains and adds K48-linked chains to signaling mediators like RIPK1, effectively terminating the inflammatory cascade. Loss or dysfunction of A20 in DCs leads to spontaneous activation, resulting in the breakdown of self-tolerance and the development of systemic autoimmune conditions (PubMed: 21163941). Consequently, A20 is a major therapeutic target; enhancing its activity is explored for treating autoimmune diseases like rheumatoid arthritis, while its targeted inhibition in DCs is being investigated to boost the efficacy of cancer vaccines and anti-tumor immunity. The protein's complex role as both a guardian against inflammation and a potential barrier to anti-tumor responses makes it a high-interest molecule for biotech analysts focusing on precision immunology.

Other names

A20OTUD7CTNFA1P3Zinc finger protein A20

A20 acts as a dual ubiquitin-editing enzyme that terminates NF-κB signaling by removing K63-linked polyubiquitin chains from mediators such as RIPK1 and TRAF6, and subsequently catalyzing the addition of K48-linked polyubiquitin chains to target these proteins for proteasomal degradation (UniProt P21583).