Structural Biochemistry/TAX1BP1

TAX1BP1

TAX1BP1 (Tax1-binding protein 1) plays a role in the negative regulation of NF- kB (transcription factors nuclear factor-kB) and IRF3 (interferon regulatory factor 3) signaling by regulating ubiquitin-editing enzyme A20 in the anti-flammatory and antiviral signaling pathways. This is to regulate the inflammatory and antimicrobial responses that are triggered in the body. TAX1BP1 also serves as a transcriptional coactivator for nuclear receptors and viral transactivators. TAX1BP1 protein is known to be highly conserved across species.

Structure

TAX1BP1 is known to form coiled-coil structures as well as two helix-loop-helix regions responsible for homodimerization. The N terminal of TAX1BP1 contains a SKIP carboxyl homology domain (SKICH), although the typical function of SKICH that defines it as a membrane targeting domain has not yet been seen in TAX1BP1’s. At the C terminus there are two zinc finger domains which contain highly conserved ‘PPXY’ motifs that are known to bind to a ‘WW’ domain of proteins. These zinc finger domains are ubiquitin-binding domains that have also been known to allow TAX1BP1 to bind to the motor protein myosin VI which is involved in cellular processes such as endocytosis, secretion, membrane ruffling, and cell motility. TAX1BP1 also contains a 14-3-3 binding motif of unknown function.

References

Verstrepen, Lynn, Kelly Verhelst, Isabelle Carpentier, and Rudi Beyaert. "Cell Press." Cell Press. n. page. Print.