TNFAIP3 Antibody from MyBioSource.com

Description: A20, also referred to as TNF-alpha-induced protein 3 (TNFAIP3), is cytokine-inducible protein that functions to inhibit apoptosis and activate NF-kappaB (1, 2). It was first identified as a TNF-alpha inducible primary response gene in human umbilical vein endothelial cells, and encodes a 790-amino acid protein containing seven Cys2/Cys2-zinc finger motifs (3). Constitutive expression of A20 is observed in lymphoid tissues (4), but it is transiently expressed in a variety of cell types in response to inflammatory signals such as TNF-alpha (3, 5), IL-1 (3, 5), phorbol esters (6), and LPS (7). Expression of A20 can confer resistance to apoptosis and NF-kappaB activation triggered by these signals, probably through interference with TRAF (TNF receptor associated factor) family members (8, 9), and interaction with the NF-kappaB inhibiting protein ABIN (10). Studies also show that A20 contains site-specific ubiquitin modifying activity that can contribute to its biological functions (11, 12). The amino-terminus of A20 contains de-ubiquitinating (DUB) activity for Lys63 branches, such as those found in TRAF6 and RIP, while the carboxyl-terminus contains ubiquitin ligase (E3) activity for Lys48 branches of the same substrates and leads to their degradation (12).
Function: Ubiquitin-editing enzyme that contains both ubiquitin ligase and deubiquitinase activities. Involved in immune and inflammatory responses signaled by cytokines, such as TNF-alpha and IL-1 beta, or pathogens via Toll-like receptors (TLRs) through terminating NF-kappa-B activity. Essential component of a ubiquitin-editing protein complex, comprising also RNF11, ITCH and TAX1BP1, that ensures the transient nature of inflammatory signaling pathways. In cooperation with TAX1BP1 promotes disassembly of E2-E3 ubiquitin protein ligase complexes in IL-1R and TNFR-1 pathways; affected are at least E3 ligases TRAF6, TRAF2 and BIRC2, and E2 ubiquitin-conjugating enzymes UBE2N and UBE2D3. In cooperation with TAX1BP1 promotes ubiquitination of UBE2N and proteasomal degradation of UBE2N and UBE2D3. Upon TNF stimulation, deubiquitinates 'Lys-63'-polyubiquitin chains on RIPK1 and catalyzes the formation of 'Lys-48'-polyubiquitin chains. This leads to RIPK1 proteasomal degradation and consequently termination of the TNF-or LPS-mediated activation of NF-kappa-B. Deubiquitinates TRAF6 probably acting on 'Lys-63'-linked polyubiquitin. Upon T-cell receptor (TCR)-mediated T-cell activation, deubiquitinates 'Lys-63'-polyubiquitin chains on MALT1 thereby mediating disassociation of the CBM (CARD11:BCL10:MALT1) and IKK complexes and preventing sustained IKK activation. Deubiquitinates NEMO/IKBKG; the function is facilitated by TNIP1 and leads to inhibition of NF-kappa-B activation. Upon stimulation by bacterial peptidoglycans, probably deubiquitinates RIPK2. Can also inhibit I-kappa-B-kinase (IKK) through a non-catalytic mechanism which involves polyubiquitin; polyubiquitin promotes association with IKBKG and prevents IKK MAP3K7-mediated phosphorylation. Targets TRAF2 for lysosomal degradation. In vitro able to deubiquitinate 'Lys-11'-, 'Lys-48'-and 'Lys-63' polyubiquitin chains. Inhibitor of programmed cell death. Has a role in the function of the lymphoid system. Required for LPS-induced production of proinflammatory cytokines and IFN beta in LPS-tolerized macrophages.
Subunit Structure: Homodimer. Interacts with TNIP1, TAX1BP1 and TRAF2. Interacts with RNF11, ITCH and TAX1BP1 only after TNF stimulation; these interaction are transient and they are lost after 1 hour of stimulation with TNF (By similarity). Interacts with YWHAZ and YWHAH. Interacts with IKBKG; the interaction is induced by TNF stimulation and by polyubiquitin. Interacts with RIPK1. Interacts with UBE2N; the interaction requires TAX1BP1. Interacts with TRAF6; the interaction is inhibited by HTLV-1 protein Tax.
Post-translational Modifications: Proteolytically cleaved by MALT1 upon TCR stimulation; disrupts NF-kappa-B inhibitory function and results in increased IL-2 production. It is proposed that only a fraction of TNFAIP3 colocalized with TCR and CBM complex is cleaved, leaving the main TNFAIP3 pool intact.
Similarity: The A20-type zinc fingers mediate the ubiquitin ligase activity. The A20-type zinc finger 4 selectively recognizes 'Lys-63'-linked polyubiquitin. The A20-type zinc finger 4-7 are sufficient to bind polyubiquitin.The OTU domain mediates the deubiquitinase activity. Belongs to the peptidase C64 family