| Purification and Quality Control | The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified LXR-alpha-LBD is greater than 95% homogeneous based on SDS-PAGE analysis. | | Unit Definition (Activity) | 1 unit equals 1 nanogram of purified protein. 20 units are sufficient for a gel-mobility shift assay and 100 units are sufficient for a protein-protein interactions assay. | | Applications | LXR-alpha-LBD has been applied in 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 | NR1H3, LXR-a; LXRA; RLD-1 | | Protein Sequence | EKLVAAQQQC NRRSFSDRLR VTPWPMAPDP HSREARQQRF AHFTELAIVS VQEIVDFAKQ
LPGFLQLSRE DQIALLKTSA IEVMLLETSR RYNPGSESIT FLKDFSYNRE DFAKAGLQVE
FINPIFEFSR AMNELQLNDA EFALLIAISI FSADRPNVQD QLQVERLQHT YVEALHAYVS
IHHPHDRLMF PRMLMKLVSL RTLSSVHSEQ VFALRLQDKK LPPLLSEIWD VHE | | Background | Liver X receptors (LXRs) are nuclear receptors that regulate the metabolism of cholesterol and bile acids (1). There are two subtypes of LXRs, LXR? and LXR?. LXRa is preferentially expressed in liver, small intestine, kidney and spleen (2, 3). In contrast, LXR? expression is ubiquitous (4). The genomic structure and the promoter regions of the two LXR genes contain specific regulatory sites, which suggest that LXRs may have physiological roles in the immune system (5). Like other nuclear receptors, LXRs heterodimerize with retinoid X receptor (RXR) for function (1). LXRs are activated by naturally occurring oxysterols and regulate the expression of target genes (6-8), including ATP binding cassette transporter 1 (ABC1), ATP binding cassette transporter 8 (ABC8) and cholesterol ester transfer protein (CETP) (9-10). The ligand binding domain (LBD) of LXR determines ligand specificity (11) and mediates the trans-activation function of the receptor (12). | | References | 1. Peet et al., (1998) Curr. Opin. Gent. Dev. 8, 571-575
2. Willy et al., (1995) Genes Dev. 9, 1033-1045
3. Apfel et al., (1994) Mol. Cell. Biol. 14, 7025-7035
4. Song et al., (1994) Proc. Natl. Acad. Sci. 91, 10809-10813
5. Alberti et al., (2000) Gene 243, 93-103
6. Janowski et al., (1996) Nature 383, 728-731
7. Lehmann et al., (1997) J. Biol. Chem. 272, 3137-3140
8. Janowski et al., (1999) Proc. Natl. Acad. Sci. 96, 266-271
9. Luo et al., (2000) J. Clin. Invest. 105, 513-520
10. Venkateswaran et al., (2000) J. Biol. Chem. 275, 14700-14707
11. Renaud et al., (1995) Nature 378, 681-689
12. Bourguet et al., (1995) Nature 375, 377-382 |
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