• 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 inhibit Topflash reporter activity in HEK293T human embryonic kidney cells. The ED    ₅₀ for this effect is 0.25-1 μg/mL in the presence of 100 ng/mL Recombinant Mouse Wnt‑3a (Catalog # )

• Source

  Chinese Hamster Ovary cell line, CHO-derived Glu30-His317, with an N-terminal HA (YPYDVPDYA) tag

• Accession #

• N-terminal Sequence    
  Analysis

  Tyr (HA), Trp37 & Ser46    
   

• Predicted Molecular Mass

  33.8, 32.7 & 30.7 kDa

• SDS-PAGE

  30-40 kDa, reducing conditions    
   

Background: sFRP-5

Secreted Frizzled Related Protein-5 (sFRP-5), also known as SARP-3, belongs to a family of Wnt‑binding proteins with homology to the ligand‑binding domain of the Frizzled receptors. sFRPs are approximately 30-35 kDa in size and contain an N‑terminal Frizzled-like domain with 10 conserved cysteines and a Netrin-like C-terminal domain (1-3). Mature human sFRP-5 shares 96% aa sequence identity with mouse and rat sFRP‑2 (4). During embryonic development, sFRP-5 is expressed in the anterior visceral endoderm, neural tube, foregut epithelium, and proliferating and prehypertrophic chondrocytes (5-8). sFRP-5 activity is required for the development of foregut, liver, ventral pancreas, and somites (6, 7). In the adult, sFRP-5 is expressed in the retinal pigment epithelium and pancreas (4, 9). sFRP-5 binds and antagonizes the function of mammalian Wnt-5a and Wnt-11 as well as   Xenopus Xwnt-8, resulting in an inhibition of both canonical and non-canonical Wnt signaling (7, 9, 10). sFRP-5 down‑regulation is common in breast and gastric cancer cells and is correlated with poor prognosis (11-13). It functions as a tumor suppressor by inhibiting epithelial‑mesenchymal transition, invasiveness, and tumorigenicity of ovarian cancer cells (14). sFRP-5 plays an important role in maintaining glucose handling and insulin sensitivity (10). It is secreted by adipocytes and is down‑regulated in mouse models of obesity and type 2 diabetes (10).

• References:

1. Bovolenta, P. et al. (2008) J. Cell Sci. 121:737.

2. van Amerongen, R. and R. Nusse (2009) Development 136:3205.

3. Rattner, A. et al. (1997) Proc. Natl. Acad. Sci. 94:2859.

4. Melkonyan, H.S. et al. (1997) Proc. Natl. Acad. Sci. 94:13636.

5. Leaf, I. et al. (2006) Genesis 44:573.

6. Satoh, W. et al. (2008) Genesis 46:92.

7. Li, Y. et al. (2008) Genes Dev. 22:3050.

8. Witte, F. et al. (2009) Gene Expr. Patterns 9:215.

9. Chang, J. et al. (1999) Hum. Mol. Genet. 8:575.

10. Ouchi, N. et al. (2010) Science 329:454.

11. Veeck, J. et al. (2008) Carcinogenesis 29:991.

12. Zhao, C. et al. (2009) BMC Cancer 9:224.

13. Ho, C.M. et al. (2010) Eur. J. Clin. Invest. 40:310.

14. Su, H.Y. et al. (2010) Int. J. Cancer 127:555.

• Long Name:

  Secreted Frizzled Related Protein 5

• Entrez Gene IDs:

  6425 (Human)

• Alternate Names:

  frizzled-related protein 1b; FRP1B; FRP-1b; SARP3; SARP-3; secreted apoptosis related protein 3; secreted apoptosis-related protein 3; secreted frizzled-related protein 5; sFRP5; sFRP-5