Fig. 1.

The main transmembrane proteins in endothelial cell-cell junctions. Endothelial cells line the blood stream and are constantly exposed to fluid shear stress (top panel). The bottom panel shows the main transmembrane proteins in endothelial cell-cell junctions (right). They are associated with tight junctions or adherens junctions as indicated, with the exception of PECAM-1, which is not associated with either type of junction. Three different claudin, JAM and nectin genes are reported to be expressed in endothelial cells (numbers/letters indicated under protein name). Intracellular proteins link transmembrane proteins to the actin cytoskeleton. There are additional junctional molecules, such as CD99 and ESAM, which are omitted for clarity.