Molecular organization, regulation and function of tricellular junctions

Tricellular junctions are specialized cell-cell junctions formed at sites where three epithelial or endothelial cells make contact at their apical side. By holding three cells together, tricellular junctions contribute to the maintenance of epithelial barrier function and mechanical integrity. In addition, recent studies have uncovered new functions of tricellular junctions at both cellular and physiological levels. In this review, we describe the architecture and molecular components of tricellular junctions and discuss how tricellular junctions participate in various biological processes.