• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.01 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. When Recombinant Human EphA1 Fc Chimera is coated at 2 μg/mL (100 μL/well), the concentration of Biotinylayed Recombinant Mouse Ephrin‑A1 Fc Chimera (Catalog # ) that produces 50% of the optimal binding response is typically 10-50 ng/mL.

• Source

  Human embryonic kidney cell, HEK293-derived

  Human EphA1 (Met1-Glu547) Accession # AAA36747	DIEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Lys26

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  83.5 kDa (monomer)

• SDS-PAGE

  100-110 kDa, reducing conditions    
   

Background: EphA1

EphA1, also known as Eph and Esk, is a 120‑130 kDa 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. Eph‑Ephrin interactions are widely involved in the regulation of cell migration, tissue morphogenesis, and cancer progression (1‑3). Mature mouse EphA1 consists of a 524 amino acid (aa) extracellular domain (ECD), a 21 aa transmembrane segment, and a 408 aa cytoplasmic domain. The ECD contains an N-terminal globular domain, a cysteine-rich domain, and two fibronectin type III domains. The cytoplasmic domain contains a juxtamembrane motif with two tyrosine residues which are the major autophosphorylation sites, a kinase domain, and a conserved sterile alpha motif (SAM) (4). Within the ECD, human EphA1 shares 84% aa sequence identity with mouse and rat EphA1. EphA1 can form pH sensitive   cis-homodimers on the cell surface (5). Membrane-bound or clustered Ephrin ligands interact with EphA1 and activate its kinase domain which is capable of Ser, Thr, and Tyr phosphorylation (6). Reverse signaling is propagated through the Ephrin ligand (7). EphA1 is widely expressed in differentiated epithelial cells, particularly in bone marrow, spleen, thymus, and testes (6, 8). It is additionally expressed on CD4  ⁺ T cells and a subpopulation of CD19  ⁺ B cells (9, 10). On CD4  ⁺ T cells, EphA1 interacts with EphA4, induces Tyr phosphorylation of PYK2, and promotes chemokine-induced chemotaxis (9, 10). EphA1 is up‑regulated or down‑regulated in a variety of human carcinomas and is implicated in tumor invasiveness (3, 7, 11). The region of Fibronectin including type I repeats #10‑12 interacts with EphA1, and this interaction plays a role in VEGF-dependent   in vitro angiogenesis (12).

• References:

1. Poliakov, A. et al. (2004) Dev. Cell 7:465.

2. Miao, H. and B. Wang (2009) Int. J. Biochem. Cell Biol. 41:762.

3. Mosch, B. et al. (2010) J. Oncol. Mar 10 Epub.

4. Hirai H. et al. (1987) Science 238:1717.

5. Bocharov, E.V. et al. (2008) J. Biol. Chem. 283:29385.

6. Douville, E.M.J. et al. (1992) Mol. Cell. Biol. 12:2681.

7. Pasquale, E.B. (2010) Nat. Rev. Cancer 10:165.

8. Coulthard, M.G. et al. (2001) Growth Factors 18:303.

9. Aasheim, H.-C. et al. (2005) Blood 105:2869.

10. Holen, H.L. et al. (2010) J. Leukoc. Biol. 87:1059.

11. Dong, Y. et al. (2009) Mod. Pathol. 22:151.

12. Masuda, J. et al. (2008) J. Biol. Chem. 283:13148.

• Entrez Gene IDs:

  2041 (Human); 13835 (Mouse)

• Alternate Names:

  EC 2.7.10; EC 2.7.10.1; EPH receptor A1; eph tyrosine kinase 1; EphA1; EPHephrin type-A receptor 1; EPHT; EPHT1erythropoietin-producing hepatoma amplified sequence; Esk; MGC163163; oncogene EPH; soluble EPHA1 variant 1; soluble EPHA1 variant 2; Tyrosine-protein kinase receptor EPH