Transmembrane tight junction

Morita K, Furuse M, Fujimoto K, and Tsukita S [1999] Claudin multigene family encoding four-transmembrane domain protein components of tight junction strands. Proc Natl Acad Sci USA 96 511-516... 

Tight junctions form selective barriers that regulate paracellular transport across epithelia and endothelia. Tight junctions are composed of transmembrane proteins (occludin, claudins, and JAMs) linked to the actin cytoskeleton through cytoplasmic ZO proteins, whereas adherence junctions are composed of the nectin-afadin system and the E-cadhcrin catenin system [143]. These cell cell adhesion proteins create the barrier and regulate electrical resistance, size, and ionic charge selectivity [144], Several experimental procedures have... 

Mitic LL, van Itallie CM (2001) Occludin and claudins transmembrane proteins of the tight junction. In Cereijido M, Anderson JM (eds) Tight Junctions (2nd edn.). CRC, Boca Raton, pp 213-230... 

Fanning, A.S., Mitic, L.L., and Anderson, J,M, (1999) Transmembrane proteins in the tight junction barrier. Journal of the American Society of Nephrology, 10, 1337-1345. 

The experiments documented in Tables 5 and 6 use confluent monolayers of pure bovine aorta endothelial cells that were grown in tissue culture petri dishes, then seeded at high concentration on collagen-coated polycarbonate filters (pore diameter = 0.8 J.m). The filters were fitted onto millipore filter holders placed in a buffer compartment with separate access to both sides of the filter and thus both the apical and basal surfaces of the endothelial cell monolayer. The asymmetry of the monolayer and the integrity of the tight junctions had previously been assessed using antifactor eight antibodies as a marker for the plasma or basal surface of the cells and transmembrane conductivity as a measure of the resistance. 

Fanning AS, Jameson BJ, Jesaitis LA, Anderson JM. The tight junction protein ZO-1 establishes a link between the transmembrane protein occludin and the actin cytoskele-ton. J Biol Chem 1998 273 29,745-29,753. 

Cell-cell contacts are made at intercellular junctions. Direct contacts between the plasma membranes of adjacent cells, particularly in epithelial tissues, are called tight junctions (Fig. 10.7). A tight junction prevents the passage of extracellular molecules and, to a varying extent, ions between the cells and even restricts the diffusion of transmembrane components within their own plasma membrane, polarizing the cells so that different membrane functions such as specific receptors, expressed on one side or another of the epithelium, are restricted to diffuse within their own section of the plasma membrane. 

Unlike adherens junctions, which form homophilic intercellular adhesion sites, tight junctions are complex structures recognized as being the molecular site of pericellular transport and its regulation. In addition to adherens and tight junctions, brain capillary endothelial cells have transmembrane receptors for matrix proteins (e.g., integrins). Impairment of either cell-cell or cell-matrix interactions can disrupt the BBB, in processes that parallel those of the peripheral endothelium. However, such impairments occur much less frequently in the brain. 

Shear stress induces larger amounts of elastin in cells and inhibits tissue calcification. Occludin, a transmembrane protein that forms tight junctions between cells, and is the main contributor to the blood-brain barrier (an obstacle to free passage of complex molecules into the central nervous system), is present in lesser amounts at high shear stress values (about 10% less at 20-30 dynes/cm ). 

Epithelia are cells organized as layers, and skin is an example. Cells in epitheUa do form gap junctions. In particularly tight membranes, these junctions are special tight junctions. The transmembrane admittance is dependent on the type of cell junctions and to what extent the epithelium is shunted by channels or specialized organs (e.g., sweat ducts in the skin). 

Chiba H, Osanai M, Murata M et al. (2008) Transmembrane proteins of tight junctions. Biochim Biophys Acta 1778 588-600. 

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