Receptor tyrosine kinase which binds promiscuously membrane-bound ephrin 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. Highly promiscuous for ephrin-A ligands it binds preferentially EFNA5. Upon activation by EFNA5 regulates cell-cell adhesion, cytoskeletal organization and cell migration. Plays a role in cardiac cells migration and differentiation and regulates the formation of the atrioventricular canal and septum during development probably through activation by EFNA1. Involved in the retinotectal mapping of neurons. May also control the segregation but not the guidance of motor and sensory axons during neuromuscular circuit development (By similarity). 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. Forms a ternary EFNA5-EPHA3-ADAM10 complex mediating EFNA5 extracellular domain shedding by ADAM10 which regulates the EFNA5-EPHA3 complex internalization and function. Interacts (phosphorylated) with PTPN1; dephosphorylates EPHA3 and may regulate its trafficking and function. Interacts (phosphorylated) with CRK; mediates EFNA5-EPHA3 signaling through RHOA GTPase activation. Interacts with NCK1 (via SH2 domain); mediates EFNA5-EPHA3 signaling (By similarity). Most abundant in the heart, brain and lung. Down-regulated by IL1-beta in neonatal cardiac myocytes. Autophosphorylates upon activation by EFNA5. Phosphorylation on Tyr-603 mediates interaction with NCK1. Dephosphorylated by PTPN1 (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily.