Transcriptional regulation of the human NAD(P)H:quinone oxidoreductase (NQO1) gene by monofunctional inducers.
The upstream region of the human NAD(P)H:quinone oxidoreductase (NQO1) gene contains a functional antioxidant responsive element (ARE) and an overlapping 12-O-tetradecanoyl-phorbol-13-acetate responsive element (TRE), with the sequence TGACTCAGCA. We show that the ARE (TGACNNNGCA) is required for induction by redox cycling phenolics (p-benzoquinone, catechol and hydroquinone), which are monofunctional inducers and induce NQO1 without the requirement for activation by cytochrome P-450. The TRE (TGACTCA) is involved only in basal expression. A plasmid containing overlapping ARE-TRE (TGACTCAGCA) sequences (-587 to -379) from the NAD(P)H:quinone oxidoreductase gene was transiently transfected into Hep G2 cells. In the absence of inducers, basal expression was 4-fold higher than in F9 cells (which lack AP-1 activity). Using subcloned oligonucleotides containing the ARE-TRE sequence (-473 to -440), the ARE sequence alone (TCA changed to GAC) and the TRE sequence alone (GC changed to TA), the basal level of expression was in the order: TRE > TRE-ARE > ARE in Hep G2 cells. Using F9 cells, basal expression was detected using the combination ARE-TRE sequence or the ARE, but not the TRE alone, p-Benzoquinone, catechol and hydroquinone, but not resorcinol, induced gene expression in both Hep G2 and F9 cells via the ARE-TRE and ARE sequences, but the TRE sequence did not contribute to this induction. We therefore conclude that induction of human NAD(P)H:quinone oxidoreductase by monofunctional inducers is via the ARE and not the TRE, and that the induction is mediated by proteins other than Fos and Jun.
Wang
B
B
Food Molecular Biochemistry Department, Norwich Laboratory, Colney, UK.
Williamson
G
G
D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D001483:Base Sequence; D016227:Benzoquinones / Q000378:metabolism / Q000494:pharmacology; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D002396:Catechols / Q000378:metabolism / Q000494:pharmacology; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics; D051546:Cyclooxygenase 2; D005786:Gene Expression Regulation; D006801:Humans; D006873:Hydroquinones / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D011955:Receptors, Drug / Q000378:metabolism; D012118:Resorcinols / Q000378:metabolism / Q000494:pharmacology; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D016227:Benzoquinones; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D002396:Catechols; D006873:Hydroquinones; D011955:Receptors, Drug; D012118:Resorcinols; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; C004532:quinone; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D016660:NAD(P)H Dehydrogenase (Quinone); D015500:Chloramphenicol O-Acetyltransferase; D011493:Protein Kinase C; C034221:catechol; C031927:hydroquinone; C031389:resorcinol