Receptor tyrosine kinase which binds promiscuously membrane-bound ephrin-A 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. Binds with a low affinity EFNA3 and EFNA4 and with a high affinity to EFNA1 which most probably constitutes its cognate/functional ligand. Upon activation by EFNA1 induces cell attachment to the extracellular matrix inhibiting cell spreading and motility through regulation of ILK and downstream RHOA and RAC. Also plays a role in angiogenesis and regulates cell proliferation. May play a role in apoptosis. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Homodimer. Forms a signaling complex with LCK; PTK2B/PYK2 and PI3-kinase upon activation by EFNA1; regulates T-lymphocytes migration. Interacts (via SAM domain) with ILK (via ANK repeats); stimulated by EFNA1 but independent of the kinase activity of EPHA1. Interacts (kinase activity-dependent) with PTK2/FAK1 (By similarity). Preferentially expressed in epithelial cells including skin, kidney, liver and thymus (PubMed:11519828, PubMed:18802966). Expressed in myogenic progenitor cells (PubMed:27446912). In myogenic progenitor cells, expressed during the acquisition of muscle stem cell properties, from 18.5 dpc to adulthood. Phosphorylated. Autophosphorylation is stimulated by its ligand EFNA1 (By similarity). Ubiquitinated. Mice display a partially-penetrant uterovaginal and tail development defects. The uterovaginal defect is due to a defect in apoptosis during development. Belongs to the protein kinase superfamily. Tyr protein kinase family. Ephrin receptor subfamily.