• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <1.0 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. Immobilized rmEphA3/Fc Chimera at 2 µg/mL (100 µL/well) can bind rhEphrin A5 Fc Chimera with a linear range of 0.08-5 ng/mL.     Optimal dilutions should be determined by each laboratory for each application.  

• Source

  Mouse myeloma cell line, NS0-derived

  Mouse EphA3 Glu21 - His541 (Thr323Ala & Glu476Gln) Accession # Q8BRB1	IEGRMD	Human IgG1 (Pro100 - Lys330)	6-His tag
  N-terminus			C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Glu21

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  86 kDa (monomer)

• SDS-PAGE

  110 kDa, reducing conditions

Background: EphA3

EphA3, also known as Cek4, Mek4, Hek, Tyro4, and Hek4, is a 135 kDa glycosylated member of the transmembrane Eph receptor tyrosine kinase family. The A and B classes of Eph proteins are distinguished by Ephrin ligand binding preference but have a common structural organization. EphA3 preferentially binds to Ephrin-A5. Eph-Ephrin interactions are widely involved in the regulation of cell migration, tissue morphogenesis, and cancer progression (1, 2). The 520 amino acid (aa) extracellular domain (ECD) of mouse EphA3 contains an N-terminal Ephrin binding region, a cysteine-rich region, and two fibronectin type II domains. The 419 aa cytoplasmic domain contains the tyrosine kinase domain and a sterile alpha motif (SAM) (3, 4). Within the ECD, mouse EphA3 shares 96% and 98% aa sequence identity with human and rat EphA3, respectively. Alternate splicing generates a secreted isoform that consists of nearly the entire ECD. EphA3 is expressed in the developing forebrain, retinal axons, some spinal cord motor neurons, and the heart where it plays an important role in axonal repulsion and organ morphogenesis (5 ‑ 8). It is upregulated on some hematopoietic and solid tumor cells and on astrocytes surrounding injured nervous tissue (5, 9 - 11). EphA3 ligation inhibits cellular adhesion to fibronectin as well as cellular migration (9, 10). Transmembrane EphA3 associates   in cis with ADAM10 which then promotes the cleavage   in trans of Ephrin-A5 (12). It also associates   in cis with Ephrin-A5 on retinal axons, thereby preventing the activation of EphA3 by Ephrin-A (13). Multiple tyrosine residues within the cytoplasmic region of EphA3 become phosphorylated during ligand-induced signaling (14, 15).

• References:

1. Pasquale, E.B. (2005) Nat. Rev. Mol. Cell Biol. 6:462.

2. Merlos-Suarez, A. and E. Batlle (2008) Curr. Opin. Cell Biol. 20:194.

3. Sajjadi, F.G. et al. (1991) New Biol. 3:769.

4. Lackmann, M. et al. (1998) J. Biol. Chem. 273:20228.

5. Chiari, R. et al. (2000) Cancer Res. 60:4855.

6. Kudo, C. et al. (2005) J. Comp. Neurol. 487:255.

7. Kilpatrick, T.J. et al. (1996) Mol. Cell. Neurosci. 7:62.

8. Stephen, L.J. et al. (2007) Dev. Biol. 302:66.

9. Smith, L.M. et al. (2004) Exp. Cell Res. 292:295.

10. Clifford, N. et al. (2008) J. Cell. Biochem. 105:1250.

11. Irizarry-Ramirez, M. et al. (2005) J. Neurotrauma 22:929.

12. Janes, P.W. et al. (2005) Cell 123:291.

13. Carvalho, R.F. et al. (2006) Nat. Neurosci. 9:322.

14. Shi, G. et al. (2010) Cell Res. June epub.

15. Hu, T. et al. (2009) Biochemistry 48:6369.

• Long Name:

  Eph Receptor A3

• Entrez Gene IDs:

  2042 (Human); 13837 (Mouse)

• Alternate Names:

  Cek4; EC 2.7.10; EC 2.7.10.1; EK4; EPH receptor A3; EphA3; EPH-like kinase 4; ephrin type-A receptor 3; ETK; Hek4; HEKETK1eph-like tyrosine kinase 1; human embryo kinase 1; TYRO4 protein tyrosine kinase; Tyro4; Tyrosine-protein kinase receptor ETK1; Tyrosine-protein kinase TYRO4