JAMs (Junctional Adhesion Molecules)

Members of the junctional adhesion molecule (JAM) family are type I transmembrane glycoproteins of the immunoglobulin (Ig) superfamily that are localized in the tight junctions between endothelial or epithelial cells and appear to be involved in leukocyte transmigration. JAM-A, also known as platelet adhesion molecule 1 (PAM-1) and platelet F11 receptor, contains two V-type Ig-like domains, forms homodimers, and interacts with LFA-1. JAM-B (vasculoendothelial or VE-JAM) and JAM-C each contain two Ig domains (one V-type and one C2-type), a cytoplasmic PDZ-binding motif and a PKC phosphorylation site. JAM-C interacts with MAC-1 and facilitates JAM-B interaction with integrin alpha 4 beta 1.