• Species Reactivity

  Human

• Specificity

  Detects human Follistatin-like 1/FSTL1 in direct ELISAs and Western blots. In direct ELISAs and Western blots, 100% cross-reactivity with recombinant mouse FSTL1 is observed.

• Source

  Monoclonal Rat IgG    _2B Clone # 229007

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human Follistatin-like 1/FSTL1    
  Met1-Ile308    
  Accession # Q12841

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  1 µg/mL

  Recombinant Human Follistatin-like 1/FSTL1 (Catalog # )    
  under non-reducing conditions only    
   

• 
  

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

• Reconstitution

  Reconstitute at 0.5 mg/mL in sterile PBS.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & Storage

  Use a manual defrost freezer and avoid repeated freeze-thaw cycles.    

• 12 months from date of receipt, -20 to -70 °C as supplied.

• 1 month, 2 to 8 °C under sterile conditions after reconstitution.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: Follistatin-like 1/FSTL1

Follistatin-like 1 (FSL1 or FSTL1), also known as FRP (follistatin-related protein), Flik (follistatin-like), and TSC-36 (TGF-beta 1-stimulated clone 36), is a secreted 45‑55 kDa extracellular glycoprotein belonging to the BM-40/SPARC/Osteonectin family (1-3). The human FSTL1 cDNA encodes 308 amino acids (aa), including a 20 aa signal sequence, a cysteine-rich Follistatin (EGF- and kazal-like) domain, two apparently non-functional EF-hand calcium-binding motifs, and a von Willebrand Factor C homology domain (1, 3). Mature human FSTL1 shares 94%, 95%, 98% and 99% aa identity with mouse, rat, bovine and equine FSTL1, respectively. FSTL1 was first identified as a TGF-beta-induced protein from a mouse osteoblast cell line (4). It is ubiquitously expressed in early mouse development, but is mainly mesenchymal later in development (5). In humans, FSTL1 is a common rheumatoid arthritis auto-antigen (2). It is reported to be either pro-inflammatory due to promoting inflammatory cytokine secretion, or to prevent autoimmune arthritis by inhibiting matrix metalloproteinase (MMP) and prostaglandin expression (6-9). In muscle and heart, it appears to be protective and promotes endothelial cell functions such as revascularization after ischemia, probably due to promoting expression and activation of the protein kinase AKT1 (10, 11). Cardiac and circulating FSTL1 is generally increased in conditions such as heart failure and acute coronary syndrome (11, 12). FSTL1 also appears to be a tumor suppressor, showing down-regulated expression in many human cancers (4, 14, 15). In vitro, it slows proliferation and MMP-dependent migration, and increases FAS-dependent apoptosis of tumor cell lines (14).

• References:

1. Zwijsen, A. et al. (1994) Eur. J. Biochem. 225:937.

2. Tanaka, M. et al. (1998) Int. Immunol. 10:1305.

3. Hambrook, H.O. et al. (2004) J. Biol. Chem. 279:11727.

4. Shibanuma, M. et al. (1993) Eur. J. Biochem. 217:13.

5. Adams, D. et al. (2007) Gene Expr. Patterns 7:491.

6. Clutter, S.D. et al. (2009) J. Immunol. 182:234.

7. Miyamae, T. et al. (2006) J. Immunol. 177:4758.

8. Kawabata, D. et al. (2004) Arthritis Rheum. 50:660.

9. Tanaka, M. et al. (2003) Int. Immunol. 15:71.

10. Ouchi, N. et al. (2008) J. Biol. Chem. 283:32802.

11. Oshima, Y. et al. (2008) Circulation 117:3099.

12. Lara-Pezzi, E. et al. (2008) Endocrinology 149:5822.

13. Widera, C. et al. (2009) Clin. Chem. 55:1794.

14. Chan, Q.K. et al. (2009) Carcinogenesis 30:114.

15. Mashimo, J. et al. (1997) Cancer Lett. 113:213.

• Entrez Gene IDs:

  11167 (Human); 14314 (Mouse); 79210 (Rat)

• Alternate Names:

  Flik; FLJ50214; Follistatin-like 1; Follistatin-like protein 1; follistatin-related protein 1; Follistatin-related Protein; FRP; FRPFLJ52277; FSL1; FSTL1; TSC-36