Novex™ Claudin Antibody Sample Pack

Description

• The purified, unconjugated antibodies in Claudin Antibody Sample Pack are specific to human, mouse, rat and dog Claudin
• Validated applications for antibodies in Claudin Antibody Sample Pack are ELISA, immunofluorescence, tissue staining and Western blotting
• Applications: validated for ELISA, immunofluorescence, tissue staining and Western blotting (Please see the manual for recommended usage for each antibody.) Reactivity: human, mouse, rat and dog Claudin (Please see the manual for species reactivity of each antibody.) Product size: 80μg pack size Tight junctions are specialized regions of cell-cell contact that are particularly abundant in luminal epithelial cell sheets
• In freeze-fracture electron micrographs, tight junctions are visualized as belt-like bands of anastomosing sealing strands (TJ strands) that completely encircle the lateral surfaces of each cell
• TJ strands on adjacent cells are presumed to interact with each other to form a sort of 'molecular gasket' that prevents ions, water and other molecules from leaking between cells and thus, from one side of the sheet to the other
• In addition to this so-called 'barrier' function, the 'fence' function of tight junctions plays an important role in maintaining epithelial cell-polarity by blocking the diffusion of membrane proteins between apical (luminal) and basolateral cell surfaces
• Confinement of the glucose symport to apical surfaces allows glucose to be transported vectorially from the lumen, through the cell, and into the bloodstream
• Several peripheral membrane proteins are associated with tight junctions including ZO-1, ZO-2, ZO-3 (members of membrane-associated guanylate-kinase family), cingulin, the 7H6 antigen, Rab-3b, symplekin
• While their precise functions are not known, roles for these proteins have been suggested in tight junction assembly and maintenance; signal transduction; and the regulation of tight junction permeability
• Furthermore, a growing body of evidence suggests that actin filaments play a major role in regulating tight junction permeability
• Until recently, the only transmembrane protein identified in association with tight junctions was occludin, a ∼65 kDa protein with four transmembrane domains
• Despite widespread expectation, a critical structural role for occludin in TJ strands was ruled out by the observation of apparently normal tight junctions formed between cells disrupted at both occludin alleles
• Fortunately, a closer examination of isolated tight junctions uncovered two related ∼22 kDa, four-transmembrane domain proteins, claudin-1 and claudin-2, with no similarity to occludin
• In contrast to occludin, which induces only a small number of short strands at cell-cell contact sites when introduced into fibroblasts lacking tight junctions, claudin-1 and -2 induce networks of strands characteristic of true tight junctions
• Though inconclusive, these findings suggest that claudin-1 and -2 are major structural components of TJ strands and that occludin plays some other accessory role
• Interest in the tight junction field continues to rise following the discovery of claudins -3, -4, -5, -6, -7, -8, -15, and -16, and experimental results suggesting that tight junctions in different tissues are comprised of distinct sets of claudin family proteins.