• Purity

  >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie? Blue Staining

• Endotoxin Level

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

• Activity

  Measured by its ability to induce Topflash reporter activity in HEK293T human embryonic kidney cells. The ED    ₅₀ for this effect is 0.5?2.0 ng/mL in the presence of 5 ng/mL Recombinant Mouse Wnt?3a (Catalog # ).

• Source

  Chinese Hamster Ovary cell line, CHO-derived Gln22-His272

• Accession #

• N-terminal Sequence    
  Analysis

  No results obtained: Gln22 predicted

• Predicted Molecular Mass

  28.3 kDa

• SDS-PAGE

  36-45 kDa, reducing conditions

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: R-Spondin 3

R-Spondin 3 (RSPO3, roof plate-specific spondin 3), also called cysteine-rich and single thrombospondin domain containing-1 (Cristin 1), is an ~31 kDa secreted protein that shares ~40% amino acid (aa) identity with the other three R-Spondin family members (1, 2). All are positive modulators of Wnt/ beta -catenin signaling, but each has a distinct expression pattern (1-4). Like other R-spondins,R-Spondin 3 contains two adjacent cysteine-rich furin-like domains (aa 35-135) with one potential N-glycosylation site (aa 36), followed by a thrombospondin (TSP-1) motif (aa 147-207) and a region rich in basic residues (aa 211-269). Only the furin-like domains are needed for beta -catenin stabilization (2). Within aa 21-209, human R-Spondin 3 shares 93%, 92%, 97%, 96% and 92% aa identity with mouse, rat, equine, bovine and canine R-Spondin 3, respectively. Potential isoforms of 279 and 297 aa diverge at aa 210 and 276, respectively (5). Mouse R-Spondin 3 is critical for development of the placental labyrinthine layer, probably by promoting VEGF expression and thus vascular development (6, 7). It is also essential for expression of the placenta-specific transcription factor, Gcm1. In the mouse embryo, R-Spondin 3 is often expressed by or located near endothelial cells (6). It is found in the roof plate, tail, somites, otic vesicles, cephalic mesoderm, truncus arteriosus, atrioventricular canal of the developing heart, and strongly but transiently in developing limbs (4, 7). R-Spondins regulate Wnt/ beta -catenin by competing with the Wnt antagonist DKK-1 for binding to the Wnt co-receptors LRP-6 and Kremen, reducing their DKK-1-mediated internalization (8, 9). Reports differ on whether R-Spondins bind LRP-6 directly (8-10). R-Spondin 3 has also been identified as an oncogene (11).

• References:

1. Chen, J-Z. et al. (2002) Mol. Biol. Rep. 29:287.

2. Kim, K.-A. et al. (2008) Mol. Biol. Cell 19:2588.

3. Hendrickx, M. and L. Leyns (2008) Develop. Growth Differ. 50:229.

4. Nam, J.-S. et al. (2007) Gene Expr. Patterns 7:306.

5. Entrez Accession # EAW48114 and EAW48116.

6. Kazanskaya, O. et al. (2008) Development 135:3655.

7. Aoki, M. et al. (2007) Dev. Biol. 301:218.

8. Binnerts, M.E. et al. (2007) Proc. Natl. Acad. Sci. USA 104:14700.

9. Nam, J.-S. et al. (2006) J. Biol. Chem. 281:13247.

10. Wei, Q. et al. (2007) J. Biol. Chem. 282:15903.

11. Theodorou, V. et al. (2007) Nat. Genet. 6:759.

• Long Name:

  Roof Plate-specific Spondin 3

• Entrez Gene IDs:

  84870 (Human); 72780 (Mouse)

• Alternate Names:

  Cristin 1; CRISTIN1; FLJ14440; hPWTSR; hRspo3; Protein with TSP type-1 repeat; PWTSR; Roof plate-specific spondin-3; RSPO3; R-spondin 3 homolog (Xenopus laevis); RSpondin 3; R-Spondin 3; R-spondin-3; Thrombospondin type-1 domain-containing protein 2; thrombospondin, type I, domain containing 2; THSD2