Claudins: Structural and Functional Molecular Constituents of Tight Junction Barrier

Abstract

Tight junctions, the most apical component of intercellular junctions, play pivotal roles in epithelial barrier by sealing the intercellular space. Very recently claudins were identified as the major molecular components of tight junction. Claudins not only work as adhesion molecules but also form tight junction strands probably by their polymerizing activity in the plasma membranes. Identification of claudins has enabled us to examine the molecular mechanism of epithelial barrier and permeability.