Ligand Binding Domain of Ephrin type-A Receptor 10
Ephrin receptors (EphRs) comprise the largest subfamily of receptor tyrosine kinases (RTKs). Class EphA receptors bind GPI-anchored ephrin-A ligands. There are ten vertebrate EphA receptors (EphA1-10), which display promiscuous interactions with six ephrin-A ligands. EphA10, which contains an inactive tyr kinase domain, may function to attenuate signals of co-clustered active receptors. EphA10 is mainly expressed in the testis. EphRs contain a ligand binding domain and two fibronectin repeats extracellularly, a transmembrane segment, and a cytoplasmic tyrosine kinase domain. Binding of the ephrin ligand to EphR requires cell-cell contact since both are anchored to the plasma membrane. The resulting downstream signals occur bidirectionally in both EphR-expressing cells (forward signaling) and ephrin-expressing cells (reverse signaling). Ephrin/EphR interaction results in cell-cell repulsion or adhesion.