• Purity

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

• Endotoxin Level

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

• Activity

  Measured by its ability to bind anthrax protective antigen (PA) in a functional ELISA. Scobie, H.M.     et al. (2003) Proc. Natl. Acad. Sci. USA     100:5170.

• Source

  Mouse myeloma cell line, NS0-derived Gln34-Asn317, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  No results obtained: Gln34 predicted

• Predicted Molecular Mass

  31.4 kDa

• SDS-PAGE

  35-40 kDa, reducing conditions

Background: CMG-2/ANTXR2

Capillary Morphogenesis Gene-2 (CMG-2) is a widely expressed anthrax toxin receptor (ATR) family protein (1 - 3). CMG-2 is a 55 kDa type I transmembrane (TM) protein that contains a 33 amino acid (aa) signal sequence, a 284 aa extracellular domain (ECD), a 24 aa TM segment, and a 147 aa cytoplasmic domain. There are three additional isoforms. Isoforms 4 shows a 12 aa insertion in the cytoplasmic region; isoform 2 shows a 103 aa deletion in the ECD; and isoform 3 is a truncated, 20 kDa, 289 aa soluble form. The main functional domain of CMG-2 is an extracellular integrin-like von Willebrand factor type A (VWA) domain with a metal ion dependent adhesion site (MIDAS). This domain adheres selectively to collagen type IV and laminin (1 - 5). CMG-2 isoform 2 is induced in HUVEC as they undergo capillary formation in collagen matrices   in vitro (3). CMG-2 is mutated in juvenile hyaline fibromatosis and infantile systemic hyalinosis disorders, and several of these mutations result in loss of laminin binding (6). CMG-2 and the related protein ATR/TEM8 serve as receptors for the protective antigen (PA) of   Bacillus Anthracis (1, 2). After binding the VWA domain, PA undergoes furin-type cleavage, forms a heptameric receptor/PA pre-pore and binds LF or EF toxin subunits (5, 7, 8). Transport to low pH endosomes, which requires CMG-2 ubiquitination and interaction with the LDL receptor related protein LRP6 (9, 10), allows PA pore formation and release of toxin to the cytoplasm (10, 11). Soluble CMG-2 VWA domain acts as a dummy receptor that can protect cultured cells from anthrax intoxication (2). Within the extracellular region, human CMG-2 shares 84%, 81%,89% and 93% amino acid sequence homology with mouse, rat, bovine, and canine CMG-2, respectively. CMG-2 VWA domain also shares 60% aa identity with ATR/TEM8.

• References:

1. Scobie, H.M. and J.A.T. Young (2005) Curr. Opin. Microbiol. 8:106.

2. Scobie, H.M. et al. (2003) Proc. Natl. Acad. Sci. USA 100:5170.

3. Bell, S.E. et al. (2001) J. Cell Sci. 114:2755.

4. Lacy, D.B. et al. (2004) Proc. Natl. Acad. Sci. USA 101:6367.

5. Santelli, E. et al. (2004) Nature 430:905.

6. Dowling, O. et al. (2003) Am. J. Hum. Genet. 73:957.

7. Wigelsworth, D.J. et al. (2004) J. Biol. Chem. 279:23349.

8. Go, M.Y. et al. (2006) J. Mol. Biol. 360:145.

9. Abrami, L. et al. (2006) J. Cell Biol. 172:309.

10. Wei, W. et al. (2006) Cell 124:1141.

11. Lacy, D.B. et al. (2004) Proc. Natl. Acad. Sci. USA 101:13147.

• Long Name:

  Capillary Morphogenesis Protein 2

• Entrez Gene IDs:

  118429 (Human); 71914 (Mouse)

• Alternate Names:

  anthrax toxin receptor 2; ANTXR2; Capillary morphogenesis gene 2 protein; capillary morphogenesis protein 2; cI-35; CMG2; CMG-2; CMG2MGC111533; CMG-2MGC45856; FLJ31074; ISH; JHF; JHS