Receptor tyrosine kinase which binds promiscuously transmembrane ephrin-B family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling. May play a role in axon guidance during nervous system development. May also play an important redundant role with other ephrin-B receptors in development and maturation of dendritic spines and synapse formation. More generally, may play a role in targeted cell migration and adhesion. Upon activation by ephrin-B ligands activates the MAPK/ERK and the JNK signaling cascades to regulate cell migration and adhesion respectively. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Heterotetramer upon binding of the ligand. The heterotetramer is composed of an ephrin dimer and a receptor dimer. Oligomerization is probably required to induce biological responses (By similarity). Maternally expressed, it decreases at mid blastula transition and reappears at late neurulation. Expressed at higher levels in the anterior and dorsal regions of embryonic stages 16, 24 and 37. In adult it appears to be ubiquitously expressed with higher expression in brain and ovary. Expression in the brain, brachial arches, trigeminal facial ganglion, and the retina of swimming tadpole stage of development. Phosphorylated. Autophosphorylation is stimulated by ligands (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily.