Ephrin Receptor - Activation

Activation

The extracellular domain of Eph receptors is composed of a highly conserved globular ephrin ligand-binding domain, a cysteine-rich region and two fibronectin type III domains. The cytoplasmic domain of Eph receptors is composed of a juxtamembrane region with two conserved tyrosine residues, a tyrosine kinase domain, a sterile alpha motif (SAM), and a PDZ-binding motif. Following binding of an ephrin ligand to the extracellular globular domain of an Eph receptor, tyrosine and serine residues in the juxtamembrane region of the Eph become phosphorylated allowing the intracellular tyrosine kinase to convert into its active form and subsequently activate or repress downstream signaling cascades.