EPH-RELATED RECEPTORS AND THEIR LIGANDS - MEDIATORS OF CONTACT-DEPENDENT CELL-INTERACTIONS

Recent studies of the large families of Eph-related receptor tyrosine kinases and their ligands suggest that they have key roles in embryoni c development. These receptors mediate cell contact dependent signalli ng by binding to membrane-bound ligands, and certain ligands may thems elves transduce signals. Functional studies indicate that in a number of tissues the receptors and ligands are expressed in complementary do mains and mediate repulsive interactions that restrict cell and axon m igration. In addition, they can also stimulate cell mig:ration. Eph-re lated receptors and their ligands are therefore mediators of cell inte ractions required for tissue patterning and neuronal pathfinding durin g development. The potential clinical implications of these findings a re discussed.