• Purity

  >95%, 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 induce adhesion of ATDC5 mouse chondrogenic cells. The ED    ₅₀ for this effect is 0.25-1.5 μg/mL.

• Source

  Mouse myeloma cell line, NS0-derived Ser28-Cys661, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Ser28

• Structure / Form

  Monomer

• Predicted Molecular Mass

  69 kDa

• SDS-PAGE

  83-90 kDa, reducing conditions

Background: CRTAC1

Cartilage acidic protein 1 (CRTAC1), also known as CEP‑68, is a 95 kDa glycosylated protein that contains four FG‑GAP domains and one EGF‑like domain. An integrin‑binding RGD motif is present in the human protein but absent in the mouse and rat proteins. Mature human CRTAC1 shares 89% amino acid sequence identity with mouse and rat CRTAC. It is secreted by chondrocytes into the extracellular matrix of cartilage (1, 2). It is also up‑regulated in type II alveolar epithelial cells upon dexamethasone exposure (3). CRTAC1B, otherwise known as LOTUS, is an 85 kDa alternatively spliced isoform that has a substituted C‑terminal region with a potential transmembrane segment (2, 4). CRTAC1B is preferentially expressed in select regions of the brain on neuronal growth cones and neurite shafts (2, 4). It associates with the Nogo Receptor (NgR) and prevents Nogo‑induced growth cone collapse (4, 5). In mouse, CRTAC1B plays an important role in axonal bundling and formation of the lateral olfactory tract (4).

• References:

1. Steck, E. et al. (2001) Biochem. J. 353:169.

2. Steck, E. et al. (2007) Matrix Biol. 26:30.

3. Ballard, P.L. et al. (2010) Am. J. Physiol. Lung Cell. Mol. Physiol. 299:L36.

4. Sato, Y. et al. (2011) Science 333:769.

5. Kurihara, Y. et al. (2012) Biochem. Biophys. Res. Commun. 418:390.

• Long Name:

  Cartilage Acidic Protein 1

• Entrez Gene IDs:

  55118 (Human); 72832 (Mouse); 171438 (Rat)

• Alternate Names:

  ASPIC; ASPIC1; ASPIC1CEP-68acidic secreted protein in cartilage; cartilage acidic protein 1; CEP68; chondrocyte expressed protein 68 kDa CEP-68,68 kDa chondrocyte-expressed protein; CRTAC1; FLJ10320