| Purification and Quality Control | The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified RXR-LBD is greater than 95% homogeneous based on SDS-PAGE analysis. |
| Unit Definition (Activity) | 1 unit equals 1 nanogram purified protein. 20 units are sufficient for an in vitro transcription assay and 100 units are sufficient for a ligand binding or a protein-protein interaction assay. |
| Applications | RXR-LBD has been applied in in vitro transcription assays, DNA and protein-protein interactions 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. |
| Synonym | FLJ00280; FLJ00318; FLJ16020; FLJ16733; MGC102720; NR2B1 and Homo sapiens retinoid X receptor alpha (RXRA). |
| Protein Sequence | MGMKREAVQE ERQRGKDRNE NEVESTSSAN EDMPVERILE AELAVEPKTE TYVEANMGLN
PSSPNDPVTN ICQAADKQLF TLVEWAKRIP HFSELPLDDQ VILLRAGWNE LLIASFSHRS
IAVKDGILLA TGLHVHRNSA HSAGVGAIFD RVLTELVSKM RDMQMDKTEL GCLRAIVLFN
PDSKGLSNPA EVEALREKVY ASLEAYCKHK YPEQPGRFAK LLLRLPALRS IGLKCLEHLF
FFKLIGDTPI DTFLMEMLEA PHQMT |
| Background | Retinoid X receptor (RXR) serves as a promiscuous heterodimerization partner for many nuclear receptors through the identity box, a 40-amino acid subregion within the ligand binding domain (LBD). RXR partners include thyroid hormone receptors (TRs), retinoic acid receptors (RARs), peroxisome proliferator-activated receptor, several constitutive active orphan nuclear receptors (e.g. nuclear growth factor I-B), oxysterol receptors, and constitutive androstane receptors. RXRs also form homodimers to mediate the effects of 9-cis-retinoic acid (9-cRA). Depending on these protein-protein interactions, RXR-containing complexes have distinct ligand-dependent and constitutive functions (1, 2). The LBD is functionally complex and mediates ligand binding, receptor homo- and heterodimerization, repression of transcription in the absence of ligand, and ligand-dependent activation of transcription (3). Hormone binding to the structurally conserved LBD of the RXR triggers a conformational change that principally affects the conserved C-terminal transactivation helix H12 involved in transcriptional activation (4). Coactivators directly recruited by liganded receptors include members of the steroid receptor coactivator/p160 family such as SRC-1, transcriptional intermediary factor 2/glucocorticoid receptor interacting protein 1, and RAC3/activator of thyroid and retinoic acid receptors/amplified in breast cancer 1 (5). |
| References | 1. Mangelsdorf et al., (1995) Cell 83, 841-850
2. Mangelsdorf et al., (1995) Cell 83, 835-839
3. Nakashima et al., (1999) Science 284, 479-482
4. Egea et al., (2001) J. Mol. Biol. 307, 557-576
5. Leo et al., (2000) Gene 245, 1-11 |
| Image of SDS-PAGE /Western-blot |  |
