Claudin 3 ELISA Kits

The protein encoded by the gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. Claudins (CLDN) determine the barrier features of tight junction. Claudins are small (20Ð27 kilodalton (kDa) transmembrane proteins which are found in many organisms, ranging from nematodes to human beings, and are very similar in their structure. They have four transmembrane domains, two extracellular loops and cytoplasmic tails. Claudins are a family of proteins which, along with occludin, are the most important components of the tight junctions (zonulae occludentes). Tight junctions establish the paracellular barrier that controls the flow of molecules in the intercellular space between the cells of an epithelium. They have four transmembrane domains, with the N-terminus and the C-terminus in the cytoplasm.

They control the paracellular permeability of the tight junctions in epithelial and endothelial cells forming single cell layers. Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are comprised of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extra cytoplasmic leaflet. Claudins play central role in the gate functions. The dual nature of the TJ gate (barrier and permeability) is evident in claudin functions. They not only create a barrier preventing free diffusion of solutes but also generate the paracellular pore pathway with unique cation- or anion-selectivity. Claudins may become useful markers for detection and diagnosis, as well as possible targets for therapy.