Figure 1.

Schematic representation of the basic structural transmembrane and peripheral membrane components of tight junctions (TJs). TJs are the most apical intercellular junctions in epithelial cells (lower insert). TJs consist of a complex interaction of three core protein components: (i) transmembrane proteins (occludin, claudins, junctional adhesion molecules [JAM] and tricellulin) (ii) Accessory proteins (Zonulae occludins 1–3), and (iii) cytoskeletal proteins (actin etc.). Changes in the expression and location of these proteins can lead to significant changes in the epithelial barrier function. Upper insert shows a transversal view of three cells bound by TJs, highligting the role of tricellulin junction.