RXR, Retinoid X receptor

TF transcription factor, R receptor, Fur ferric uptake regulation protein, NF-kB nuclear factor-kB, AP-1 activator protein-1, Egr-1 early growth response-1, VDR la,25-dihydroxy-vitamin D3 receptor, RXR retinoid X receptor, PPARy peroxisome proliferator-activated receptor y NFAT nuclear factor of activated T-cells, HSF heat shock factor, p53 tumor suppressor p53, HIF-1 hypoxia inducible factor-1. ... 

Figure 5.34 Mechanism of induction of CYP2B6 by a chemical such as the drug phenobarbital. This drug activates a nuclear receptor (CAR).This combines with the retinoid X receptor and binds to PBREM, as specific section of the CYP gene, which stimulates the production of CYP2B6 mRNA leading to the production of CYP2B6 protein and enzyme. Abbreviations CAR, constitutive androstane receptor RXR retinoid X receptor PBREM, phenobarbital-responsive enhancer module.

Figure 5.35 Mechanism of the receptor-mediated induction of CYP3A4 by a chemical. The inducer-receptor (PXR) complex enters the nucleus, binds with RXR, and the complex binds to the ER6 region of the CYP gene. This induces the production of CYP3A4 mRNA, which leads to the production of CYP3A4 protein and functional enzyme. Abbreviations RXR, retinoid X receptor-a PXR, pregnane X receptor ER6, everted repeat with a 6-kilobase spacer.

Abbreviations-. GPCR = G protein coupled receptor RXR = retinoid X receptor RTK = receptor tyrosine kinase RSTK = receptor serine/threonine kinase RACK = receptor for activated protein kinase C MAPK = mitogen-activated protein kinase. 

Figure 9.10 Illustration depicting DNA elements found in CYP3A genes and the activation of the human pregnane X receptor (PXR) by ligand (RIF) and subsequent transcriptional activation of CYP3A4 gene by the PXR/RXR heterodimer. dNR-1-3, nuclear receptors 1, 2, and 3, respectively PXR, pregnane X receptor RXR, retinoid X receptor RIF, rifampicin SRC-1, steroid receptor co-activator XREM, xenobiotic responsive enhancer module.

Figure 9 Generalised scheme for an ecdysteroid-regulated gene switch system RXR = retinoid X receptor, EcR = ecdysteroid receptor, EcRE = ecdysteroid response element, MuA = muristerone A, PoA = ponasterone A.

Abbreviations a-BFAs anteiso-branched fatty acids AGP acyl carrier protein BHLH active soluble domain of SREBP CNS central nervous system DSD delta 5 desaturase D6D delta 6 desaturase ER endoplasmic reticulum Hik histidine kinase HUFA highly unsaturated fatty acid LXR liver X receptor MUFA monounsaturated fatty add NF-Y nuclear factor Y PLs phospholipids PP peroxisome proliferator PPAR PP-activated receptor PPRE PP response element PUFA polyunsaturated fatty acid PUFA-BP PUFA binding protein PUFA-RE PUFA response element RXR retinoid X receptor SCAP SREBP cleavage-activating protein SCD steraroyl CoA desaturase SFA saturated fatty acid SRE sterol response... 

Fig. 6. Coordinated transcriptional regulation of fatty acid desaturases and elongases in mammals. PUFA, polyunsaturated fatty acids +, stimulation inhibition LXR, liver X receptor RXR retinoid X receptor SREBP, sterol regulatory element binding protein ChREBP, carbohydrate response element binding protein Mix, Max-like receptor PPAR-ot, peroxisome proliferator activated receptor alpha LXRE, liver X receptor response element SRE, sterol response element ChoRE, carbohydrate response element PPRE, peroxisome proliferator response element. (See color plate section, plate no. 6.)...

Abbreviations used in this review APL, acute promyelocytic leukaemia CEF, chick embryo fibroblasts CRABP, cellular retinoic acid-binding protein ODC, ornithine decarboxylase RA, retinoic acid RARE, retinoic acid responsive element RAR, retinoic acid receptor RXR, retinoid X receptor TEMPO, 2,2,6,6-tetramethylpiperidine Y-oxide TOC, tracheal organ culture TPA, 12-<2-tetradecanoylphorbol-13-acetate TTNN, 6-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-2-naphthanoic acid TTNPB, 4-((.Q-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2- naphthyl)propenyl)benzoic acid. 

The abbreviations used are HMG-CoA, 3-hydroxy-3-melhylglutaryl-CoA CAT, chloramphenicol acetyltransferase PPAR, peroxisome proliferator-activated receptor PPRE, peroxisome proliferator-responsive element NRRE, nuclear receptor responsive element RXR, retinoid X receptor hRXRa, human 9-cis-retinoic acid receptor a mPPARa, mouse peroxisome proliferator-activated receptor a COUP-TP, chicken ovalbumin upstream-promoter transcription factor, HNF-4, hepatocyte nuclear factor 4 EMSA, electrophoretic mobility shift analysis tk, thymidine kinase NEFA, nonesterified fatty acids... 

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