Targeting tight junction proteins-significance for drug development.

The choice of drug target and the ability to deliver drug to those targets are pivotal in drug development. Most druggable targets are membrane proteins, such as G-protein-coupled receptors, channels and transporters. However, little attention has been paid to potential druggable targets in the membrane proteins of tight junctions (TJs), through which adjacent cell membranes contact one another. Recent progress in the cell biology of TJs provides new insights into the barrier and fence functions of TJs, suggesting that TJ components are promising candidates for drug discovery. In this review, we summarize the cell biology of TJs and discuss the TJ-based drug discovery.