MOLECULAR DISSECTION OF TIGHT JUNCTIONS

In epithelial and endothelial cells, the tight junction (TJ) seals cel ls to create a primary barrier to the diffusion of solutes across the cell sheet, and it also works as a boundary between the apical and bas olateral membrane domains to create their polarization. An integral me mbrane protein working at TJ is postulated to exist, but it has remain ed elusive for quite some time. Most recently, using mAbs, we identifi ed an integral membrane protein named occludin that was exclusively lo calized at TJ both in epithelial and endothelial cells. Here we overvi ew our recent studies on the structure and function of occludin.