Cadherins are a family of transmembrane glycoproteins involved in the Ca2+-dependent cell-cell adhesion that occurs in many tissues. Members of this family include P-Cadherin, E-Cadherin (uvomorulin), N-Cadherin, R-Cadherin, Cadherin-5, L-CAM, and EP-Cadherin. These proteins are similar in their domain structure (45-74% amino acid conservation), Ca2+ and protease sensitivity, and molecular weight. However, cadherins have distinct tissue expression patterns and immunological reactivities. M (muscle)-Cadherin, another member of the Cadherin family, was discovered in myogenic mouse cells where it is present at low levels in myoblasts. It is expressed in prenatal and adult skeletal muscle and plays a role in skeletal muscle cell differentiation, particularly the fusion of myoblasts into myotubes. It is upregulated upon induction of myotube formation. M-Cadherin also forms complexes with the catenins in skeletal muscle cells, which then interact with the cytoskeleton. Therefore, it is thought that the M-Cadherin-cytoskeleton interaction may play a role in aligning myoblasts during fusion.