Purity ~90% (SDS-PAGE). EphA8, also known as Hek3 and Eek, is a 120kD glycosylated member of the Eph family of transmembrane receptor tyrosine kinases. The A and B classes of Eph proteins are distinguished by Ephrin ligand binding preference but have a common structural organization. EphA4 binds and is activated by class A Ephrins but not class B Ephrins. Eph-Ephrin interactions are widely involved in the regulation of cell migration, tissue morphogenesis, and cancer progression. The 512aa extracellular domain (ECD) of human EphA8 contains an N-terminal Ephrin binding region, a cysteine rich region, and two fibronectin type III domains (FnIII). The 442aa cytoplasmic domain contains the tyrosine kinase domain and a sterile alpha motif (SAM). Within the ECD, human EphA8 shares 97% aa sequence identity with mouse and rat EphA8. EphA8 is expressed in neurons in the mesencephalon of the developing brain, particularly in the rostral tectum and the superior colliculus. It is enriched at the t