The tight junction has been characterized as a domain of focal fusions of the exoplasmic leaflets of the lipid bilayers from adjacent epithelial cells. Approximating membranes to within fusion distance is a thermodynamically unfavorable process and requires the participation of membrane-bridging or -fusion proteins. No known tight junction protein exhibits such activities. Annexin A2 (A2), in p...

T H~ tight junction, or zonula occludens, is an organeile of crucial importance to the development and function of most organ systems in vertebrates because it enables epithelia and endothelia to create eompositionaily distinct fluid compartments. The tight junction forms a continuous permeability barrier between adjacent cells that regulates the flux of molecules through the paracellular space...

Celiac disease also known as gluten-sensitive enteropathy is characterized by intestinal mucosal damage and malabsorption from dietary intake of wheat, rye or barley. Symptoms may appear with introduction of cereal in the first 3 years of life. A second peak in symptoms occurs in adults during the third or forth decade and even as late as eight decade of life. The prevalence of this disease is ...

The development of human cancers is frequently associated with a failure of epithelial cells to form tight junctions and to establish proper apicobasal polarity. Interestingly, the oncogenic potential of the adenovirus E4-ORF1 protein correlates with its binding to the cellular PDZ proteins MUPP1, MAGI-1, ZO-2 and SAP97, the first three of which assemble protein complexes at tight junctions. Gi...

Occludin is the only known integral membrane protein localized at the points of membrane- membrane interaction of the tight junction. We have used the Xenopus embryo as an assay system to examine: (a) whether the expression of mutant occludin in embryos will disrupt the barrier function of tight junctions, and (b) whether there are signals within the occludin structure that are required for tar...

By employing the theoretical method based on tight-binding, we study electronic band structure of single-wall carbon nanotube (CNT) superlattices, which the system is the made of the junction between the zigzag and armchair carbon nanotubes. Exactly at the place of connection, it is appeared the pentagon–heptagon pairs as topological defect in carbon hexagonal network. The calculations are base...

The effects of tight junction structure on water and solute fluxes across proximal tubular epithelium were examined with fiber-matrix equations previously derived by Curry and Michel (1980. Microvascular Research. 20:96-99). Using plausible estimates of tight junction fiber length and width the model predicts solute (Ps) and water permeability (Lp) coefficients that agree with the measured valu...

Claudins are tetraspan transmembrane tight-junction proteins that regulate epithelial barriers. In the distal airspaces of the lung, alveolar epithelial tight junctions are crucial to regulate airspace fluid. Chronic alcohol abuse weakens alveolar tight junctions, priming the lung for acute respiratory distress syndrome, a frequently lethal condition caused by airspace flooding. Here we demonst...

Claudin-18 (CLDN18) is a tight junction protein with two distinct isoforms: lung-type (CLDN18.1) and stomach-type (CLDN18.2). Stomach-type claudin-18 plays a vital role in gastric barrier function by forming a paracellular barrier between epithelial cells, as it is the major tight-junction component in the stomach. However, recent studies suggest that CLDN18.2 may also function as a tumor suppr...

Zonula occludens-1 (ZO-1) was the first tight junction protein to be cloned, and has been implicated as an important scaffold protein. It contains multiple domains that bind a diverse set of junction proteins. However, the molecular functions of ZO-1 and related proteins such as ZO-2 and ZO-3 have remained unclear. We now show that gene silencing of ZO-1 causes a delay of ~3 hours in tight junc...