Rat liver NAD(P)H: Quinone reductase. Regulation of quinone reductase gene expression by planar aromatic compounds and determination of the exon structure of the quinone reductase structural gene.
We have determined the effect of beta-naphthoflavone and the azo dye, sudan III, on the level of quinone reductase mRNA in a responsive rat hepatoma cell line. Our data indicate that both of these planar aromatic compounds produce a 4-5-fold elevation in quinone reductase mRNA. The induction of quinone reductase mRNA can be blocked by cycloheximide, suggesting a requirement for ongoing protein synthesis in the induction process. We have determined the exon structure of the quinone reductase structural gene. The gene is separated into six exons by five introns. A "TATA" box is located 29 base pairs upstream from the transcription initiation site. A "CCAAT" sequence is found at position -129, and an inverted "GC" box is located at position -78. Quinone reductase promoter-chlor-amphenicol acetyltransferase fusion genes containing different lengths of the 5'-flanking region were transfected into rat and human hepatoma cells. Treatment of the transfected cells with beta-naphthoflavone or sudan III resulted in a 4-5-fold elevation in chloramphenicol acetyltransferase activity. These data suggest the presence of a cis-acting regulatory element(s) in the 5'-flanking region of the quinone reductase structural gene which regulates inducible expression.
Bayney
R M
RM
Department of Molecular Pharmacology and Biochemistry, Merck Sharp & Dohme Research Laboratories, Rahway, New Jersey 07065.
Morton
M R
MR
Favreau
L V
LV
Pickett
C B
CB
D000595:Amino Acid Sequence; D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology*; D001483:Base Sequence; D001571:Benzoflavones / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D005091:Exons / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D005796:Genes / Q000187:drug effects*; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D007438:Introns; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008113:Liver Neoplasms; D008114:Liver Neoplasms, Experimental; D008969:Molecular Sequence Data; D016660:NAD(P)H Dehydrogenase (Quinone); D015345:Oligonucleotide Probes; D011808:Quinone Reductases / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats; D013194:Staining and Labeling; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured / Q000201:enzymology; D019324:beta-Naphthoflavone
D001391:Azo Compounds; D001571:Benzoflavones; D005419:Flavonoids; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D019324:beta-Naphthoflavone; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases; D005982:Glutathione Transferase; C033006:sudan III