EphA1

EphA1 is the founding member of the Eph receptor tyrosine kinase family, originally identified simply as Eph (EPHT1). It is expressed in epithelial and endothelial cells and binds membrane-anchored ephrin-A ligands such as ephrin-A1 and ephrin-A5, triggering bidirectional signaling that reorganizes the actin cytoskeleton and modulates cell adhesion and repulsion. In endothelium, EphA1-ephrin-A1 interactions help control vascular assembly and angiogenic sprouting, and EphA1 levels are altered in several carcinomas, with reported roles in both promoting and restraining tumor cell motility depending on context. Recombinant EphA1 extracellular domain and kinase domain reagents support ephrin-binding studies and phosphotyrosine signaling assays.