Cell adhesion molecule involved in the establishment and/or maintenance of cell integrity. May play a role in vamp3-mediated vesicular transport and recycling of different receptor molecules. May be involved in the formation and regulation of the tight junction (TJ) paracellular permeability barrier in epithelial cells. May induce primordial adhesive contact and aggregation of epithelial cells in a Ca(2+)-independent manner. May be involved in epithelial movement during corneal sheet formation and regeneration. May play a role in the regulation of cell shape and movement by modulating the Rho-GTPase activity. May be involved in skeletal muscle and heart development as well as in the maintenance of heart function. May also be involved in striated muscle regeneration and in the regulation of cell spreading (By similarity). Detected at points of cell-cell contact in confluent epithelial sheets. Colocalizes with components of the adherens and tight junctions (By similarity). Belongs to the popeye family.