• Species Reactivity

  Human

• Specificity

  Detects human FGF-21 in direct ELISAs. In direct ELISAs, less than 10% cross-reactivity with recombinant mouse FGF-21, recombinant human (rh) FGF-3, -4, -6 or -10 is observed and no cross-reactivity with rhFGF-5 or rhFGF-9 is observed.

• Source

  Monoclonal Mouse IgG2b Clone # 461804

• Immunogen

  E. coli-derived recombinant human FGF-21    
  His29-Ser209    
  Accession # Q9NSA1

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 750

Applications

• Recommended    
  Concentration

  Sample

• Intracellular Staining by Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  HepG2 human hepatocellular carcinoma cell line fixed with paraformaldehyde and permeabilized with saponin

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Store the unopened product at 2 - 8 °C. Do not use past expiration date.

Background: FGF-21

Fibroblast growth factor 21 (FGF-21) is a member of the FGF gene family, which currently contains 22 human members. Based on its structure, it is further classified as an FGF-19 subfamily member. This subfamily includes FGF-19, -21, and -23. Like all other FGF subfamilies, FGF-19 subfamily members contain a 120 amino acid (aa) core FGF domain that exhibits a beta -trefoil structure (1, 2). Unlike other FGF subfamilies, FGF-19 subfamily members apparently exhibit poor binding to ECM, resulting in highly diffusible molecules (3). The cDNA for FGF-21 predicts a 209 aa polypeptide that contains a 28 aa signal sequence and a 181 aa mature region (4). Notably, FGF-21, as well as FGF-19 show limited binding to heparin (4). One potential alternate splice form has been reported. It shows a 43 aa substitution for the C‑terminal 12 aa of the standard form (5). Mature human FGF-21 shows 81% aa identity to mouse FGF-21, and is known to be active on mouse cells (4, 6). The FGF‑19 subfamily is considered endocrine in nature. All three subfamily members impact some aspect of metabolism, all three are induced by a nuclear receptor heterodimer that includes RXR, and all three utilize Klotho family members for signal transduction (7, 8, 9). FGF-21 is produced by hepatocytes in response to free fatty acid (FFA) stimulation of a PPARa/RXR dimeric complex (3, 7, 10, 11). This situation occurs clinically during starvation, or following the ingestion of a high-fat/low-carbohydrate diet. Upon FGF-21 secretion, white adipose tissue is induced to release FFAs from triglyceride stores. Once FFAs reach hepatocytes, they are oxidized and reduced to acetyl-CoA. The acetyl-CoA is recombined into 4-carbon ketone bodies (acetoacetate and beta -hydroxybutyrate), released, and transported to peripheral tissues for TCA processing and energy generation (11, 12).

• References:

1. Itoh, N. and D.M. Ornitz (2004) Trends Genet. 20:563.

2. Mohammadi, M. et al. (2005) Cytokine Growth Factor Rev. 16:107.

3. Huang, X. et al. (2006) Mol. Carcinog. 45:934.

4. Nishimura, T. et al. (2000) Biochim. Biophys. Acta 1492:203.

5. GenBank Accession #: EAW52401 (2006).

6. Ford, A.M. et al. (2005) J. Clin. Invest. 115:1627.

7. Moore, D. D. (2007) Science 316:1436.

8. Ogawa, Y. et al. (2007) Proc. Natl. Acad. Sci. USA 104:7432.

9. Kurosu, H. et. al. (2007) J. Biol. Chem. 282:26687.

10. Lundasen, T. et al. (2007) Biochem. Biophys. Res. Commun. 360:437.

11. Badman, M.K. et al. (2007) Cell Metab. 5:426.

12. Inagaki, T. et al. (2007) Cell Metab. 5:415.

• Long Name:

  Fibroblast Growth Factor 21

• Entrez Gene IDs:

  26291 (Human); 56636 (Mouse)

• Alternate Names:

  FGF21; FGF-21; fibroblast growth factor 21