Membrane-achored ligands for the Eph-related receptor tyrosine kinases. Class A ephrins are GPI-anchored and bind to EphA receptors, ephrinBs are transmembrane and bind to EphB receptors and to EphA4. The consequence of an ephrin–Eph interaction depends on the cell type, but is often a repulsion cue, e.g. of the nerve growth cone. Binding leads to the formation of clusters of Ephs (on one cell) and ephrins (on the other) and the transmembrane ephrins becomes tyrosine phosphorylated on their cytoplasmic domains when they are bound by the receptor: both receptor and ligand respond to the binding interaction. This also seems to be true for the GPI-linked ephrins, although the reverse signalling mechanism presumably involves association with other signalling molecules in a lipid domain.
http://www.pantherdb.org/genes/geneList.do?searchType=basic&fieldName=all&listType=2&fieldValue=ephrin&organism=all The Panther database gives additional information on the ephrin family.
Subjects: Medicine and Health — Chemistry.