• Purity

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

• Endotoxin Level

  <0.01 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 typical ED    ₅₀ is 8-40 ng/mL in the presence of 5 ng/mL Recombinant Mouse Wnt?3a (Catalog # ).

• Source

  Chinese Hamster Ovary cell line, CHO-derived Met1-Gln265

• Accession #

• N-terminal Sequence    
  Analysis

  Ser21

• Predicted Molecular Mass

  27 kDa

• SDS-PAGE

  40-43 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 1

R-Spondin 1 (RSPO1, Roof plate-specific Spondin 1), also known as cysteine-rich and single thrombospondin domain containing protein 3 (Cristin 3), is a 27 kDa secreted protein that belongs to the R-Spondin family (1, 2). R-Spondins share around 40% aa identity. All regulate Wnt/ beta ?catenin signaling, but have distinct expression patterns (1?3). Like other R-spondins, R-Spondin 1 contains two adjacent cysteine-rich furin-like domains (amino acids (aa) 34?135) followed by a thrombospondin (TSP-1) motif (aa 147?207) and a region rich in basic residues (aa 211?263). Only the furin-like domains are needed for beta -catenin stabilization (2, 4). A putative nuclear localization signal at the C?terminus may allow some expression in the nucleus (5). R?Spondin 1 contains one potential N?glycosylation site. Mouse R?Spondin 1 shares 98%, 94%, 94%, 93%, 92% and 88% aa identity with rat, human, horse, cow, goat and dog RSPO-1, respectively, within aa 21?209. R?Spondin 1 is expressed in early development at the roof plate boundary and is thought to contribute to dorsal neural tube development (3, 5). In humans, rare disruptions of the R-Spondin 1 gene are associated with tendencies for XX sex reversal (phenotypic male) or hermaphroditism, indicating a role for R?Spondin 1 in gender-specific differentiation (6, 7). Disruption is also associated with palmoplantar keratosis (6, 7). Postnatally, R-Spondin 1 is expressed by neuroendocrine cells in the intestine, adrenal gland and pancreas, and by epithelia in kidney and prostate (8). Injection of recombinant R?Spondin 1 in mice causes activation of beta -catenin and proliferation of intestinal crypt epithelial cells, and ameliorates experimental colitis (8, 9). R?Spondin 1 appears to regulate Wnt/ beta ?catenin by competing with the Wnt antagonist DKK-1 for binding to the Wnt co?receptor, Kremen (10). This competition reduces internalization of DKK?1/LRP?6/Kremen complexes (10). Reports differ on whether R-Spondin 1 binds LRP-6 directly (10?12).

• References:

1. Lowther, W. et al. (2005) J. Virol. 79:10093.

2. Kim, K.-A. et al. (2006) Cell Cycle 5:23.

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

4. Kazanskaya, O. et al. (2004) Dev. Cell 7:525.

5. Kamata, T. et al. (2004) Biochim. Biophys. Acta 1676:51.

6. Tomaselli, S. et al. (2007) Hum. Mutat. Dec 17 [Epub ahead of print]

7. Parma, P. et al. (2006) Nat. Genet. 38:1304.

8. Kim, K.-A. et al. (2005) Science 309:1256.

9. Zhao, J. et al. (2007) Gastroenterology 132:1331.

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

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

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

• Long Name:

  Roof Plate-specific Spondin 1

• Entrez Gene IDs:

  284654 (Human); 192199 (Mouse)

• Alternate Names:

  Cristin 3; CRISTIN3; FLJ40906Roof plate-specific spondin-1; hRspo1; roof plate-specific spondin; RSPO; RSPO1; RSpondin 1; R-Spondin 1; R-spondin homolog (Xenopus laevis); RSPONDIN; R-spondin1; R-spondin-1