TAX1BP1
TAX1BP1 (Tax1 binding protein 1, also known as TXBP151 and CALCOCO3) is a ubiquitin-binding adapter protein involved in inflammatory, antiviral and innate immune processes. It also acts as a receptor in selective autophagy. Browse Assay Genie's current range of TAX1BP1 research reagents below, or read on for the biology behind the target.
TAX1BP1 is a ubiquitin-binding adapter that restrains inflammatory and antiviral signalling. It acts as an adapter for the ubiquitin-editing enzyme A20/TNFAIP3, bringing it to its substrates so that they can be inactivated. In this way it negatively regulates NF-κB and IRF3 signalling. It disrupts the interactions between the E3 ubiquitin ligase TRAF3 and TBK1/IKBKE, which attenuates 'Lys63'-linked polyubiquitination of TBK1 and so limits IFN-beta production. It also recruits A20/TNFAIP3 to the ubiquitinated signalling proteins TRAF6 and RIPK1. Their deubiquitination then disrupts IL-1 and TNF-induced NF-κB signalling.
TAX1BP1 also inhibits virus-induced apoptosis. It recruits the E3 ligase ITCH, which induces 'Lys-48'-linked polyubiquitination and degradation of MAVS and thereby attenuates MAVS-mediated apoptosis signalling. As an autophagy receptor, it facilitates xenophagic clearance of pathogenic bacteria such as Salmonella typhimurium and Mycobacterium tuberculosis. Once NBR1 is recruited to SQSTM1-ubiquitin condensates, TAX1BP1 acts as the major recruiter of RB1CC1 to these condensates and promotes their autophagic degradation. It also mediates the autophagic degradation of other substrates, including TICAM1. UniProt lists its locations as the cytoplasm, mitochondrion, preautophagosomal structure and autophagosome.
The TAX1BP1 gene was first identified as encoding a binding partner of the HTLV-1 Tax1 protein, which gave rise to the name. NCBI Gene reports that the protein interacts with TNFAIP3 and inhibits TNF-induced apoptosis by mediating the anti-apoptotic activity of TNFAIP3. Degradation of the protein by caspase-3-like proteases is associated with TNF-induced apoptosis. Alternatively spliced transcript variants encoding different isoforms have been described. HGNC places the gene in the zinc fingers UBZ1 CCHH-type group, and mouse and rat orthologs are both named Tax1bp1.
TAX1BP1 limits NF-κB and IRF3 signalling by guiding A20/TNFAIP3 to TRAF3, TRAF6 and RIPK1 complexes, making it a focus for studies of inflammation.
As an autophagy receptor that recruits RB1CC1 to SQSTM1-ubiquitin condensates, TAX1BP1 is used to study how ubiquitinated cargo is targeted for degradation.
TAX1BP1 reduces IFN-beta production and promotes MAVS degradation through ITCH, so it is relevant to research on antiviral signalling and virus-induced apoptosis.
TAX1BP1 supports xenophagic clearance of Salmonella typhimurium and Mycobacterium tuberculosis, linking it to studies of intracellular pathogen control.
TAX1BP1 is a ubiquitin-binding adapter. It recruits A20/TNFAIP3 to signalling proteins such as TRAF6 and RIPK1, which dampens NF-κB and IRF3 signalling. It also works as an autophagy receptor, helping to clear ubiquitin condensates and intracellular bacteria through selective autophagy.
TAX1BP1 is also known as TXBP151 and CALCOCO3, and its previous name was Tax1 (human T-cell leukaemia virus type I) binding protein 1. NCBI Gene reports that alternatively spliced transcript variants encode different isoforms. Check the datasheet of any product for its validated reactivity.
Mouse and rat both have a Tax1bp1 ortholog. NCBI Gene reports that TAX1BP1 inhibits TNF-induced apoptosis by mediating TNFAIP3 activity. Its degradation by caspase-3-like proteases is associated with TNF-induced apoptosis. UniProt also describes it as inhibiting virus-induced apoptosis through MAVS degradation.
Other Tax1-binding proteins and related regulators of immune signalling and autophagy with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q86VP1; product specifications from Assay Genie datasheets.