• Purity

  >95%, 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 its binding ability in a functional ELISA.

  When rhST7 is immobilized at 0.5 µg/mL, the concentration of rhLRPAP (Catalog # 4296-LR) that produces 50% of the optimal binding response is found to be approximately 0.6‑3 μg/mL.

• Source

  Mouse myeloma cell line, NS0-derived Asn28-Ile488 with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Asn28 & Glu33

• Predicted Molecular Mass

  52.7 kDa

• SDS-PAGE

  71 kDa, reducing conditions

Background: ST7/LRP12

ST7 (Suppressor of Tumorigenicity 7), also known as RAY1, TSG7 and FAM4A1, is a type I transmembrane protein belonging to the LDLR superfamily and is designated LRP12 (1 - 3). The human ST7 cDNA encodes 859 amino acids (aa) including a 32 aa signal sequence, a 460 aa extracellular domain (ECD) containing two CUB domains and five LDLR class A domains, a 21 aa transmembrane domain, and a 346 aa cytoplasmic domain containing motifs implicated in endocytosis and signal transduction (1, 2). Human ST7 shares 95% aa sequence homology with mouse and rat, 96% with canine, and 98% with bovine, equine and porcine ST7 within the ECD. Genomic sequencing indicates the possibility of up to 18 splicing isoforms, but expression of these has not been well‑studied (3). ST7 is widely expressed in normal tissues, especially fibroblasts (1, 4). Highest mRNA levels were detected in heart and skeletal muscle (1). ST7 was originally proposed to be a tumor suppressor protein, but it is not consistently downregulated in a variety of cancers, either by mutation or loss of heterozygosity (1, 4 - 7). In certain cancers, expression may even be upregulated (8). Expression may be associated with downregulated expression of extracellular matrix molecules that are involved in remodeling, such as SPARC, IGFBP5 and several matrix metalloproteinases, and modulation of in vivo tumorigenicity (4, 5).

• References:

1. Qing, J. et al. (1999) Oncogene 18:335.

2. Battle, M.A. et al. (2003) Biochemistry 42:7270.

3. Vincent, J.B. et al. (2002) Genomics 80:283.

4. Zenclusen, J.C. et al. (2001) Nat. Genet. 27:392.

5. Hooi, C.F. et al. (2006) Oncogene 25:3924.

6. Sivasundaram, K. et al. (2003) Oncol. Rep. 10:1737.

7. Dong, S.M. and D. Sidransky (2002) Clin. Cancer Res. 8:2939.

8. Garnis, C. et al. (2004) Oncogene 23:2582.

• Long Name:

  Low Density Lipoprotein Receptor-related 12

• Entrez Gene IDs:

  29967 (Human); 239393 (Mouse)

• Alternate Names:

  DKFZp762O2113; FAM4A1; LRP12; Protein FAM4A1; Protein HELG; RAY1; SEN4; ST7; subfamily A, member 1; suppression of tumorigenicity 7 (breast); suppression of tumorigenicity 7; suppressor of tumorigenicity 7 protein; TSG7