RSPO-1, Recombinant, Human (R-Spondin 1, Roof Plate-specific Spondin1)

R-Spondin 1 (RSPO1, roof plate-specific spondin1), also called cysteine-rich and single thrombospondin domain containing-3 (Cristin 3), is a 27kD secreted protein that shares ~40% amino acid identity with the other three R-Spondin family members (1, 2). All are positive modulators of Wnt/b-catenin signaling, but each has a distinct expression pattern (1-3). Like other R-spondins, R-Spondin1 contains two adjacent cysteine-rich furin-like domais (aa34-135) with one potential N-glycosylation site (aa36), followed by a thrombospondin (TSP-1) motif (aa147-207) and a region rich in basic residues (aa211-263). Only the furin-like domains are needed for b-catenin stabilization (2,4). A putative nuclear localization signal at the C-terminus may allow some expression in the nucleus (5). Potential isoforms of 200 and 236aa have an alternate, shorter N-terminus or are missing aa146-208, respectively (6). Over aa21-263, human R-Spondin 1 shares 89%, 87%, 92%, 91%, 91% and 89% aa identity with mouse, rat, equine, canine, caprine and bovine RSPO-1, respectively. R-Spondin 1 is expressed in early development a 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 (7,8). Disruption is also associated with palmoplantar keratosis (7,8). Postnatally, R-Spondin 1 is expressed by neuroendocrine cells in the intestine, adrenal gland and pancreas, and by epithelia in kidney and prostate (9). Injection of recombinant R-Spondin 1 in mice causes activation of b-catenin and proliferation of intestinal crypt epithelial cells, and ameliorates experimental colitis (9,10). R-Spondin 1 regulates Wnt/b-catenin by competing with the Wnt antagonist DKK-1 for binding to the Wnt co-receptors, Kremen and LRP-6, reducing their DKK-1-mediated internalization (11). Reports differ on whether R-Spondin 1 binds LRP-6 directly (11-13).\n\nEndotoxin: \n(same/less than) 1EU/ug (LAL)\n\nSDS-PAGE: \n39kD, reducing conditions.\n\nBiological Activity:\nMeasured by its ability to induce activation of b-catenin response in a Topflash Luciferase assay using HEK293T human embryonic kidney cells. The ED50 for this effect is typically 1-4ng/ml in the presence of 5ng/ml rmWnt-3a.\n\nStorage and Stability:\nLyophilized powder may be stored at -20 degrees C. Reconstitute with PBS, 0.1% BSA. Aliquot and store at -20 degrees C. Reconstituted product is stable for 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

R9417-45A

Size

25ug

Form

Supplied as a lyophilized powder from PBS, BSA. Reconstitute with PBS, 0.1% HSA or BSA to a concentration of 0.1mg/ml.

Purity

(same/more than) 90% (SDS-PAGE)

References

1. Chen, J-Z., et al., Mol. Biol. Rep. 29: 287 (2002). 2. Kim, K.-A., et al., Cell Cycle 5: 23 (2006). 3. Nam, J.-S., et al., Gene Expr. Patterns 7: 306 (2007). 4. Kazanskaya, O., et al., Dev. Cell 7: 525 (2004). 5. Kamata, T., et al., Biochim. Biophys. Acta 1676: 51 (2004). 6. Entrez accession # EAX07331, ABA54598. 7. Tomaselli , S., et al., Hum. Mutat. 29: 220 (2008). 8. Parma, P., et al., Nat. Genet. 38: 1304 (2006). 9. Kim, K.-A., et al., Science 309: 1256 (2005). 10. Zhao, J., et al., Gastroenterology 132: 1331 (2007). 11. Binnerts, M.E., et al., Proc. Natl. Acad. Sci. USA 104: 14,700 (2007). 12. Nam, J.-S., et al., J. Biol. Chem. 281: 13,247 (2006). 13. Wei, Q., et al., J. Biol. Chem. 282: 15,903 (2007).