Recombinant Mouse R-Spondin 4 Protein

• Reactivity: Mu
• Applications: Bioactivity

Recombinant Mouse R-Spondin 4 Protein Summary

• Details of Functionality: Measured by its ability to induce Topflash reporter activity in HEK293T human embryonic kidney cells. The ED 50 for this effect is ≤ 100 ng/mL in the presence of 10 ng/mL Recombinant Mouse Wnt-3a (Catalog # 1324-WN).
• Source: Chinese Hamster Ovary cell line, CHO-derived mouse R-Spondin 4 protein Ala19-Gln228
• Accession #: Q8BJ73
• N-terminal Sequence: Ala19
• Protein/Peptide Type: Recombinant Proteins
• Gene: Rspo4
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 23.9 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 32 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  12 months from date of receipt, -20 to -70 degreesC as supplied. 1 month, 2 to 8 degreesC under sterile conditions after reconstitution. 3 months, -20 to -70 degreesC under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein.
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Reconstitution Instructions: Reconstitute at 200 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Mouse R-Spondin 4 Protein

• C20orf182
• chromosome 20 open reading frame 182
• Cristin 4
• CRISTIN4
• dJ824F16.3
• FLJ16018
• hRspo4
• Roof plate-specific spondin-4
• RSPO4
• RSpondin 4
• R-Spondin 4
• R-spondin family, member 4
• R-spondin-4

Background

R-Spondin 4 (RSPO4, roof plate-specific spondin 4), also called cysteine-rich and single thrombospondin domain containing-4 (Cristin 4), is an ~33 kDa secreted heparin-binding protein that shares ~35% amino acid (aa) identity with three other R-Spondin family members (1-3). All are positive modulators of Wnt/ beta -catenin signaling, but R-Spondin 4 may be somewhat weaker than other R-Spondins (2). 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 (1, 4). Like other R-Spondins, mouse R-Spondin 4 (234 aa) contains a signal sequence (aa 1-19), two adjacent cysteine-rich furin-like domains (aa 85-128) with one potential tyrosine phosphorylation site (aa 114), followed by a thrombospondin (TSP-1) motif (aa 137-197) and a region rich in basic residues (aa 199-234). The furin-like domains are sufficient for beta -catenin stabilization (2). Mature mouse R-Spondin 4 shares 81%, 97%, 79%, 77% and 76% aa identity with human, rat, bovine, equine and canine R-Spondin 4, respectively. There is one potential isoform where Arg substitutes for the C-terminal 82 amino acids (5). Each R-Spondin has a distinct expression pattern (6). In the mouse, R-Spondin 4 mRNA is found during development of limb bud mesenchyme, nail beds, heart and teeth (6-8). In humans, mutations of R-Spondin 4 have been found to cause anonychia, a condition in which fingernails and toenails are absent (8-10).

1. Nam, J.-S. et al. (2006) J. Biol. Chem. 281:13247.
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. Binnerts, M.E. et al. (2007) Proc. Natl. Acad. Sci. USA 104:14700.
5. Entrez Accession # Q8BJ73, Isoform 2.
6. Nam, J.-S. et al. (2007) Gene Expr. Patterns 7:306.
7. Pemberton, T.J. et al. (2007) Dev. Dyn. 236:2245.
8. Ishii, Y. et al. (2008) J. Invest. Dermatol. 128:867.
9. Blaydon, D.C. et al. (2006) Nat. Genet. 38:1245.
10. Bergmann, C. et al. (2006) Am. J. Hum. Genet. 79:1105.

Bioinformatics

• Gene Symbol: Rspo4
• Uniprot:
  • Q8BJ73(Mouse)