Cell adhesion molecule involved in the establishment and/or maintenance of cell integrity. Involved in skeletal muscle and heart development as well as in the maintenance of heart function (PubMed:26642364). May play a role in vamp3-mediated vesicular transport and recycling of receptor molecules. 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 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). Expressed in skeletal muscle (at protein level). Morpholino knockdown of the protein causes cardiac edema in 70% of the injected morphants. They show malformed myotendinous junction and, in 80% of the morphants, skeletal muscle is characterized by myofibrillar misalignment and fiber detachment. Belongs to the popeye family.