Tumor necrosis factor alpha-induced protein 3-Nuclear factor kappa-light-chain-enhancer of activated B cells signaling axis (TNFAIP3-NF-κB axis)

The TNFAIP3-NF-κB signaling axis is a fundamental regulatory pathway that maintains immune homeostasis by terminating inflammatory responses [1, 6]. TNFAIP3, also known as A20, acts as a potent negative feedback regulator of the NF-κB transcription factor family, which is induced by pro-inflammatory stimuli such as TNF-α and Toll-like receptor ligands [3, 10]. It utilizes a dual-domain structure to edit ubiquitin chains on key signaling adapters like RIPK1, TRAF6, and NEMO, effectively dismantling the IKK complex and halting downstream gene transcription [4, 15]. Dysregulation of this axis, often characterized by loss-of-function mutations or reduced expression of TNFAIP3, is strongly associated with chronic inflammatory and autoimmune diseases like systemic lupus erythematosus and rheumatoid arthritis [2, 6]. Furthermore, TNFAIP3 serves as a tumor suppressor in various B-cell malignancies, where its absence leads to constitutive NF-κB activation and aberrant cell survival [5, 9]. Therapeutic strategies targeting this axis aim to restore TNFAIP3 function or inhibit NF-κB activity to treat inflammatory disorders and certain cancers [10, 13, 18].

Other names

A20-NF-κB axisTNFAIP3-NFKB1 pathwayA20-mediated NF-κB regulationTNFAIP3-NF-κB feedback loop

The axis functions through a negative feedback loop where TNFAIP3 (A20) terminates NF-κB activation by removing K63-linked ubiquitin chains from signaling adapters (e.g., RIPK1, TRAF6) and adding K48-linked chains to target them for proteasomal degradation [3, 4, 15].