Molecular architecture of tight junctions

• Published in: Annual review of physiology Vol. 60; no. 1; pp. 121 - 142
• Main Authors: Mitic, L L, Anderson, J M
• Format: Journal Article
• Language: English
• Published: United States Annual Reviews, Inc 01-01-1998
• Subjects: Amino Acid Sequence; Animals; Guanylate Kinases; Humans; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Molecular Sequence Data; Nucleoside-Phosphate Kinase - metabolism; Signal Transduction - physiology; Tight Junctions - chemistry; Tight Junctions - enzymology; Tight Junctions - physiology
• ISSN: 0066-4278; 1545-1585
• DOI: 10.1146/annurev.physiol.60.1.121

The tight junction creates a regulated barrier in the paracellular pathway and, together with the actin-rich adherens junction, forms a functional unit called the apical junction complex. A growing number of tight junction-associated proteins have been identified, but functions are defined for only a few. The intercellular barrier is formed by rows of the transmembrane protein occludin, which is bound on the cytoplasmic surface to ZO-1 and ZO-2. These proteins are members of the membrane-associated guanylate kinase (MAGUK) protein family and are likely to have both structural and signaling roles. Junctional plaque proteins without known functions include cingulin, p130, and 7H6; single reports describe ZA-1TJ and symplekin. Many cellular signaling pathways affect assembly and sealing of junctions. Transducing proteins, which localize within the junction, include both heterotrimeric and rho-related GTP-binding proteins, PKC-zeta and nonreceptor tyrosine kinases. Control of perijunctional actin may be the unifying mechanism for regulating paracellular permeability.