| Purification and Quality Control | The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified RXR-beta is greater than 95% homogeneous based on SDS-PAGE analysis. | | Unit Definition (Activity) | 1 unit equals 1 nanogram of purified protein. 20 units (ng) are sufficient for an in vitro transcription assay and 100 units are sufficient for a protein-protein interaction assay.
Variable exist in different lots. | | Applications | RXRβ can be 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 | DAUDI6; H-2RIIBP; MGC1831; NR2B2; RCoR-1 and Homo sapiens retinoid X receptor beta (RXRB). | | Protein Sequence | MSWAARPPFL PQRHAAGQCG PVGVRKEMHC GVASRWRRRR PWLDPAAAAA AAVAGGEQQT
PEPEPGEAGR DGMGDSGRDS RSPDSSSPNP LPQGVPPPSP PGPPLPPSTA PSLGGSGAPP
PPPMPPPPLG SPFPVISSSM GSPGLPPPAP PGFSGPVSSP QINSTVSLPG GGSGPPEDVK
PPVLGVRGLH CPPPPGGPGA GKRLCAICGD RSSGKHYGVY SCEGCKGFFK RTIRKDLTYS
CRDNKDCTVD KRQRNRCQYC RYQKCLATGM KREAVQEERQ RGKDKDGDGE GAGGAPEEMP
VDRILEAELA VEQKSDQGVE GPGGTGGSGS SPNDPVTNIC QAADKQLFTL VEWAKRIPHF
SSLPLDDQVI LLRAGWNELL IASFSHRSID VRDGILLATG LHVHRNSAHS AGVGAIFDRV
LTELVSKMRD MRMDKTELGC LRAIILFNPD AKGLSNPSEV EVLREKVYAS LETYCKQKYP
EQQGRFAKLL LRLPALRSIG LKCLEHLFFF KLIGDTPIDT FLMEMLEAPH QLA | | 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. RXR partners include thyroid hormone receptors (TRs), retinoic acid receptors (RARs), peroxisome proliferator-activated receptor (PPAR), several constitutive active orphan nuclear receptors, e.g. nuclear growth factor I-B (NGFI-B), oxysterol receptors (FXR,LXR), and constitutive androstane receptors (CAR). 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). RXRβ was originally identified as a protein able to bind to the regulatory region II of the murine major histocompatibility complex (MHC) class I promoter and referred to as H2RIIBP (2). The human RXRβ gene has been mapped to the short arm or centromeric region of chromosome 6 (6pter-q13) which also contains the MHC I locus (3). Two major RXRb isoforms in the mouse, designated RXRβ1 and RXRβ2 (GenBank accession numbers D21830 and D21831), differ in the N-terminal (A) domain with RXRβ1 containing an extra 72 amino acids. These isoform mRNAs are transcribed from two CpG island promoters and the different N-terminal exons are spliced to exons common to both isoforms from the remainder of the gene (4). Although the two mouse RXR isoforms have been characterised in some detail, less information is available about their human counterparts (5, 6). Since the expression of different RXR isoforms appears to be well conserved between species, each receptor isoform may hold a specific role in retinoid signalling. However, many RXR expression studies have not recognised the importance of establishing which RXR isoforms are expressed in a particular system. RXRβ is predominantly involved in retinoid responses in the N-type SH SY 5Y and the S-type SH S EP neuroblastoma cells (7), both derivatives of a mixed phenotype neuroblastoma cell line. | | References | 1. Chambon (1996) FASEB J. 10, 940-954
2. Hamada et al., (1989) Proc. Natl. Acad. Sci. 86, 8289-8293
3. Fleischhauer et al., (1993) Hum. Genet. 90, 505-510
4. Nagata et al., (1994) Gene 142, 183-189
5. Leid et al., (1992) Cell 68, 377-395
6. Fleischhauer et al., (1992) Nucleic Acid Res. 20, 1801-1810
7. Rana et al., (2001) FEBS Lett. 506, 39-44 | | Image of SDS-PAGE /Western-blot |  |
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