TAX1BP3 holds one PDZ domain, which uses for interactions with other proteins like the interaction with the C-terminus of Rhotekin that facilitates Rho-mediated activation of the FOS serum response element. In addition, PDZ domain interacts with beta-catenin to inhibit the transcriptional activity of beta-catenin. TAX1BP3 exists in several cell lines, such as HeLa, and is expressed in small quantities in peripheral blood leukocytes.