Xin Actin Binding Repeat Containing Protein 1 (XIRP1)

The deduced chicken and mouse proteins contain 2,562 and 1,677 amino acids, respectively. Both have an N-terminal DNA-binding domain, followed by a repeated 16-amino acid module, 1 or 2 SH3-binding motifs, and nuclear localization signals.

Xin exhibited a peripheral localization within cardiomyocytes and remained at cell-cell junctions throughout development and into adulthood. Colocalization of Xin with beta-catenin (CTNNB1) and N-cadherin (CDH2), in addition to coimmunoprecipitation experiments, suggested that Xin localized to the adherens junctions within the intercalated disc. At embryonic day 10.0, Xin was also found within developing somites and eventually at the myotendon junctions of skeletal muscle.