Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.28 (chloramphenicol acetyltransferase)
 5,100 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have identified two regions in the 5'-flanking sequence of the rat quinone reductase gene that contain xenobiotic responsive elements. The DNA sequence of the first region spans nucleotides -393 to -352 of the 5'-flanking region and shares sequence identity with the xenobiotic responsive element (XRE) described for the cytochrome P-450 CYPIA1 gene. The DNA sequence of the second region spans nucleotides -434 to -404 of the 5'-flanking region of the quinone reductase structural gene. When a synthetic oligonucleotide corresponding to nucleotides -434 to -404 was inserted in front of a heterologous promoter linked to the chloramphenicol acetyltransferase structural gene, an increase in basal level expression as well as responsiveness to beta-naphthoflavone and t-butylhydroquinone, but not 2,3,7,8-tetrachlorodibenzo-p-dioxin, was observed. The sequence, -434 to -404, did not have any sequence identity with the XRE but shared a large degree of identity with the antioxidant responsive element recently described for the rat glutathione S-transferase Ya subunit gene (Rushmore, T. H., King, R. G., Paulson, K. E., and Pickett, C. B. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 3826-3830; Rushmore, T. H., and Pickett, C. B. (1990) J. Biol. Chem. 265, 14648-14653). These results indicate that the antioxidant responsive element can be distinguished functionally from the classical XRE and is also involved in the regulation of the quinone reductase gene by planar aromatic compounds and phenolic antioxidants.
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PMID:Transcriptional regulation of the rat NAD(P)H:quinone reductase gene. Identification of regulatory elements controlling basal level expression and inducible expression by planar aromatic compounds and phenolic antioxidants. 190 Feb 96

Glutathione S-transferase (GST) Ya subunit gene expression is induced in mammalian tissues by two types of chemical agents: (i) planar aromatic compounds (e.g., 3-methylcholanthrene, beta-naphthoflavone, and 2,3,7,8-tetrachlorodibenzo-p- dioxin) and (ii) electrophiles (e.g., trans-4-phenyl-3-buten-2-one and dimethyl fumarate) or compounds easily oxidized to electrophiles (e.g., tert-butylhydroquinone). To study the mechanism of this induction, we have introduced deletions in the 5' flanking region of a mouse GST Ya subunit gene, fused it to the coding sequence for chloramphenicol acetyltransferase (CAT) activity, and transfected the Ya-CAT genes for expression into hepatoma cells. We show that a single cis-regulatory element, between nucleotides -754 and -713 from the start of transcription, is responsible for the induction by both planar aromatic and electrophilic compounds. Using murine hepatoma cell mutants defective in either the Ah-encoded aryl hydrocarbon receptor (BPrc1 mutant) or in cytochrome P1-450 gene (c1 mutant), we show that induction by planar aromatic but not by electrophilic inducers requires a functional Ah receptor and cytochrome P1-450 activity. From this it is concluded that Ya gene activation by planar aromatic compounds involves metabolism of these inducers by the phase I xenobiotic-metabolizing cytochrome P1-450 system into electrophilic compounds, which is consistent with a recently proposed model [Prochaska, H. J. & Talalay, P. (1988) Cancer Res. 48, 4776-4782]. Therefore, the regulatory sequence of the Ya gene should be considered an electrophile-responsive element (EpRE) activated exclusively by inducers containing an electrophilic center. An EpRE-containing 41-bp oligonucleotide ligated at the -187 site of the Ya gene promoter confers upon it an increase in basal activity and xenobiotic inducibility. The basal activity augments with the number of EpRE copies. DNase I protection patterns show the protection of the EpRE domain by a nuclear factor(s) that becomes more abundant upon exposure of Hepa 1c1c7 cells to tert-butylhydroquinone.
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PMID:Xenobiotic-inducible expression of murine glutathione S-transferase Ya subunit gene is controlled by an electrophile-responsive element. 216 52