Purification and Quality Control The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified RAR-beta is greater than 90% homogeneous based on SDS-PAGE analysis.
Unit Definition (Activity) 1 unit is equal to 1 nanogram of purified protein. 20-100 units are sufficient for an in vitro transcription assay and 100 units are sufficient for a protein-protein interactions assay. Variable exist in different lots.
Applications RAR beta has been applied in in vitro transcription assays, DNA and protein-protein interaction assays.
Formulation and Storage The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles.
Background Retinoic acid receptors are important in the regulation of growth and differentiation of epithelial tissues, embryonic and central nervous system development and hematopoiesis (1). Retinoids mediate their effect by two classes of nuclear receptor proteins, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs), that each consist of three isotypes (α, β, and γ) encoded in separate genes (2). Upon dimerization with RXR, RARs can bind to specific enhancer sequences in the DNA, so-called retinoic acid response elements (RAREs), resulting in transcriptional activation of target genes in the presence of ligand (3). Retinoids, the natural and synthetic vitamin A derivatives, are known to inhibit the proliferation of lung cancer and breast cancer cells and the growth of carcinogen-induced bronchogenic squamous cell carcinoma and mammary tumors, and have been used as chemoprevention agents against both types of cancer (4). A growing body of evidence supports the hypotheses that the RAR beta gene is a tumor suppressor gene and the chemopreventive effects of retinoids are due to induction of RAR beta. RAR beta expression is reduced in many malignant tumors including breast carcinoma. (5).
References 1. Kastner et al. (1995) Cell, 83, 859-869 2. Leid et al., (1992) Trends Biochem. Sci. 17, 427-433 3. Linney et al., (1992) Curr. Top. Dev. Biol. 27, 309-350 4. Zhang et al., (1996) Mutat. Res. 350, 267-277 5. Yang et al., (2002) Breast Cancer Res. Treat. 76, 167-173
DISCLAIMER
This products is recommended For RESEARCH USE ONLY and is Not qualified for Use in Diagnostic or Therapeutic Procedures.
