• Species Reactivity

  Human

• Specificity

  Detects human EphB4 in direct ELISAs and Western blots. In direct ELISAs and Western blots, no cross-reactivity with recombinant human EphA1, A2, A5, A6, A10, B2, B3, B6, recombinant mouse EphA3, A4, or recombinant rat EphB1 is observed.

• Source

  Monoclonal Rat IgG1 Clone # 395810

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human EphB4    
  Ala16-Ala539    
  Accession # AAH52804

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 350

Applications

• 
  

  Recommended    
  Concentration

  Sample

• Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  MCF‑7 human breast cancer cell line

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: EphB4

EphB4, also known as Htk, Myk1, Tyro11, and Mdk2, is a member of the Eph receptor tyrosine kinase family and binds Ephrin-B2. The A and B class Eph proteins have a common structural organization (1‑4). The human EphB4 cDNA encodes a 987 amino acid precursor that includes a 15 amino acid (aa) signal sequence, a 524 aa extracellular domain (ECD), a 21 aa transmembrane segment, and a 427 aa cytoplasmic domain (5). 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) (5). Activation of kinase activity occurs after membrane-bound or clustered ligand recognition and binding. The ECD of human EphB4 shares 89% aa sequence identity with mouse EphB4 and 42‑45% aa sequence identity with human EphB1, 2, and 3. EphB4 is expressed preferentially on venous endothelial cells (EC) and inhibits cell-cell adhesion, chemotaxis, and angiogenesis. Opposing effects are induced by signaling through Ephrin-B2 expressed on arterial EC: adhesion, endothelial cell migration, and vessel sprouting (6). EphB4 singaling contributes to new vascularization by guiding venous EC away from Ephrin-B2 expressing EC. Ephrin-B2 signaling induces arterial EC to migrate towards nascent EphB4 expressing vessels (6). The combination of forward signaling through EphB4 and reverse signaling through Ephrin-B2 promotes in vivo mammary tumor growth and tumor‑associated angiogenesis (7). EphB4 promotes the differentiation of megakaryocytic and erythroid progenitors but not granulocytic or monocytic progenitors (8, 9).

• References:

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

2. Surawska, H. et al. (2004) Cytokine Growth Factor Rev. 15:419.

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

4. Davy, A. and P. Soriano (2005) Dev. Dyn. 232:1.

5. Bennett, B.D. et al. (1994) J. Biol. Chem. 269:14211.

6. Fuller, T. et al. (2003) J. Cell Sci. 116:2461.

7. Noren, N.K. et al. (2004) Proc. Natl. Acad. Sci. 101:5583.

8. Wang, Z. et al. (2002) Blood 99:2740.

9. Inada, T. et al. (1997) Blood 89:2757.

• Long Name:

  Eph Receptor B4

• Entrez Gene IDs:

  2050 (Human); 13846 (Mouse)

• Alternate Names:

  EC 2.7.10; EC 2.7.10.1; EPH receptor B4; EphB4; ephrin type-B receptor 4; hepatoma transmembrane kinase; Htk; HTKephrin receptor EphB4; Mdk2; Myk1; soluble EPHB4 variant 1; soluble EPHB4 variant 2; soluble EPHB4 variant 3; Tyro11; Tyrosine-protein kinase receptor HTK; Tyrosine-protein kinase TYRO11