ISSN:
0066-4278
Source:
Annual Reviews Electronic Back Volume Collection 1932-2001ff
Topics:
Medicine
,
Biology
Notes:
Abstract 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1146/annurev.physiol.60.1.121
