• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <1.0 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by the ability of the immobilized protein to support the adhesion of HeLa human cervical epithelial carcinoma cells. Kiyozumi, D.     et al. (2005) Exp. Cell Res.     306:9. When 5 x 10    ⁴ cells/well are added to rhQBRICK/Fc Chimera coated plates (2.5 μg/mL, 100 μL/well), approximately 60%?80% will adhere after 1 hour at 37° C.    
     Optimal dilutions should be determined by each laboratory for each application.  

• Source

  Chinese Hamster Ovary cell line, CHO-derived

  Human QBRICK (Ser22 - Glu384) Accession # Q5H8C1	IEGRMD	Human IgG1 (Pro100 - Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Ser22

• Structure / Form

  Oligomer

• Predicted Molecular Mass

  67.8 kDa (monomer)

• SDS-PAGE

  75-85 kDa, reducing conditions

Background: QBRICK/FREM1

QBRICK, also known as Frem1 (Fras1-related extracellular matrix gene1) is a 244 kDa (predicted), secreted, extracellular matrix glycoprotein and member of the Fras1 family of proteins (1 - 3). Human QBRICK is synthesized as a 2179 amino acid (aa) precursor that has a 21 aa signal sequence and a 2158 aa mature chain (SwissProt #: Q5H8C1). The mature chain is made up of an N-terminal variable region domain containing an Arg-Gly-Asp (RGD) cell adhesive motif, 12 consecutive chondroitin sulfate proteoglycan (CSPG) repeats of approximately 120 aa, a Calx-beta domain, a second RGD sequence, and a C-terminal C-type lectin-like domain, respectively (1). In addition, there are five potential sites of N-linked glycosylation. Multiple splicing variants produce four isoforms for human QBRICK. Because of the characteristic feature of the 12 CSPG repeats, the protein was named QBRICK: “Q” stands for queen and is taken from the queen being the twelfth in a suit of playing cards, and “BRICK” stands for the repeating unit (1). Human QBRICK shares 78% aa sequence identity with mouse QBRICK. QBRICK is localized to the basement membrane in mesenchymal tissue (3). QBRICK plays a role in epidermal differentiation and is required for epidermal adhesion during embryonic development. QBRICK mediates cell-substratum adhesion through alpha V or alpha 8 integrins (1 - 4). Mutations in QBRICK and other Fras1 family proteins (i.e. Fras1 and Frem2) are associated with Fraser syndrome, a recessive multiorgan disorder characterized by crypthophthalmos, syndactyly, renal agenesis, and a variety of morphogenetic defects (2 - 4). It is postulated that QBRICK, Fras1 and Frem2 make up a ternary complex that act together to ensure adhesion between the epidermal basement membrane and the underlying mesenchyme in embryonic skin (3).

• References:

1. Kiyozumi, D. et al. (2005) Exp. Cell Res. 306:9.

2. Smyth, I. et al. (2004) Proc. Natl. Acad. Sci. U.S.A. 101:13560.

3. Kiyozumi, D. et al. (2006) Proc. Natl. Acad. Sci. U.S.A. 103:11981.

4. Smyth, I. and P. Scambler (2005) Hum. Mol. Genet. 14:R269.

• Long Name:

  FRAS-1 Related Extracellular Matrix Protein 1

• Entrez Gene IDs:

  158326 (Human)

• Alternate Names:

  BNAR; C9orf143chromosome 9 open reading frame 154; C9orf145C9orf154extracellular matrix protein QBRICK; C9orf154; DKFZp686M16108; FLJ25461; FRAS1 related extracellular matrix 1; FRAS1-related extracellular matrix protein 1; FREM1; Protein QBRICK; QBRICK; TILRR