Catenin Alpha 3 (CTNNa3)

The deduced 895-amino acid protein has a calculated molecular mass of 100 kD and contains 3 vinculin homology domains. It shares about 57% amino acid identity with other alpha-catenins. PCR detected CTNNA3 expression mainly in heart and testis. Lower amounts were also detected in brain, kidney, liver, fetal liver, and skeletal muscle.

RT-PCR of mouse tissues showed a similar, but not identical, pattern of expression. Immunolocalization of CTNNA3 in cryosections of human heart revealed CTNNA3 at intercalated discs of cardiomyocytes, where it colocalized with alpha-E-catenin. In testis, CTNNA3 localized to desmin-expressing peritubular myoid cells, but it did not colocalize with alpha-E-catenin. CTNNA3 is necessary for the formation of stretch-resistant cell-cell adhesion complexes in muscle cells.