Molecular Modulation of Intestinal Epithelial Barrier: Contribution of Microbiota
A model of the protein components of tight (TJ) and adherens junctions (AJ) in a highly polarized epithelial cell. The TJ is composed of transmembrane proteins (occludins, claudins, and JAMs) linked to an actin cytoskeleton via cytoplasmic ZO (zonula occludens) proteins. ZO-1 binds to actin. The AJ is composed of the nectin-afadin system and the E-cadherin-catenin system. Nectin’s direct partner, afadin, binds to several proteins, including ZO proteins. Thus TJs and AJs may be closely associated, forming the apical junctional complex, which is linked to the actin cytoskeleton network.