• Purity

  >90%, by SDS-PAGE with silver staining

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. Immobilized Recombinant Mouse Integrin alpha V beta 8 at 2 μg/mL can bind Recombinant Human LAP (TGF-beta 1) (Catalog # ) with an apparent K    _d <0.1 nM.  

• Source

  Chinese Hamster Ovary cell line, CHO-derived

  Mouse Integrin aV (Phe31-Val988) Accession # P43406	His-Pro	GGGSGGGS	Acidic Tail	6-His tag
  Mouse Integrin beta 8 (Glu43-Ser679) Accession # Q0VBD0	His-Pro	GGGSGGGS	Basic Tail
  N-terminus				C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Phe31 ( alpha V subunit) & Glu43 ( beta 8 subunit)     
   

• Structure / Form

  Non-covalent heterodimer

• Predicted Molecular Mass

  115 kDa ( alpha V subunit), 78 kDa ( beta 8 subunit)

• SDS-PAGE

  95 - 170 kDa, reducing conditions

Background: Integrin alpha V beta 8

Integrin  alpha V beta 8 is a type I transmembrane non-covalent heterodimer composed of a 115 kDa alpha V/CD51 subunit and an 84 kDa beta 8 subunit. The Integrin  beta 8 exclusively partners with the alpha V subunit, while alpha V forms heterodimers with beta 1, beta 3, beta 5 and beta 6 (1). Integrin  alpha V beta 8 is expressed on Schwann cells and astrocytes in the brain, vascular epithelial cells, mesangial cells in the kidney, and fibroblasts and epithelial cells in the airway (2-7). Interestingly, Integrin alpha V beta 8 is expressed by cells of the immune system, most prominently on CD4  ⁺ T cells and on dendritic cells (8). Unlike other alpha V integrins, alpha V beta 8 does not interact with the cytoskeleton or activate cytoplasmic signaling pathways (3, 9). Instead, it binds ligands containing an arginine-glycine-aspartic acid (RGD) motif, including Vitronectin, Fibrin and the latency associated peptide (LAP) (10, 11). High affinity binding of alpha V beta 8 to LAP triggers the MT1-MMP induced proteolytic cleavage of LAP and the release of active TGF-beta (12). Active TGF-beta regulates cell growth and nearby vascularization (5, 12, 13). Furthermore, Integrin alpha V beta 8-mediated TGF-beta activation in specialized dendritic cells of the intestine is crucial for maintaining immune homeostasis in the gut (14). Deletion of either alpha V or beta 8 reveals that alpha V beta 8 is required for vascular morphogenesis in the embryonic brain (15-16). The 958 amino acid mouse alpha V extracellular domain (ECD) shares 92% and 88% aa sequence identity with human and rat alpha V, respectively, while the 637 aa mouse beta 8 ECD shares 87% and 96% aa sequence identity with human and rat orthologs, respectively.

• References:

1. Luo, BH. et al. (2007) Annu.Rev.Imm.25:619.

2. Milner, R. et al. (1997) Glia 21:350.

3. Nishimura, S. et al. (1998) Brain Res. 791:271.

4. Zhu, J. et al. (2002) Development 129:2891.

5. Cambier, S. et al. (2000) Cancer Res. 60:7084.

6. Khan, S. et al. (2011) Am. J. Pathol. 178:609.

7. Araya, J. et al. (2006) Am. J. Pathol. 169:405.

8. Travis, M.A. et al. (2007) Nature 449:361.

9. Moyle, M. et al. (1991) J. Biol. Chem. 266:19650.

10. Nishimura, S. et al. (1994) J. Biol. Chem. 269:28708.

11. Chernousov, M. A. and D. J. Carey (2003) Exp. Cell Res. 291:514.

12. Mu, D. et al. (2002) J. Cell Biol. 157:493.

13. Araya, J. et al. (2006) Am. J. Pathol. 169:405.

14. Worthington, J.J. et al. (2012) Immunobiology 217:1259.

15. Cambier, S. et al. (2005) Am. J. Pathol. 166:1883.

16. Proctor, J. M. et al. (2005) J. Neurosci. 25:9940.

17. McCarty, J. H. et al. (2005) Development 132:165.

• Entrez Gene IDs:

  3685 (Human)

• Alternate Names:

  Integrin alpha V beta 8