Location of regulatory elements responsible for drug induction in the rat cytochrome P-450c gene.
The synthesis of cytochrome P-450c is induced remarkably in cultured cells as well as animal tissues in response to added chemicals such as 3-methylcholanthrene and 2,3,7,8-tetrachlorodibenzodioxin. To study this mechanism, we joined the sequence of 5'-flanking and upstream regions of the P-450c gene to the structural gene for chloramphenicol acetyltransferase. The fusion gene was introduced into Hepa-1 cells for the assay of the expressed acetyltransferase activity. At least three cis-acting regulatory regions that are responsible for the inductive expression were determined in the sequences from nucleotide -3674 to -3067, from -1682 to -1429, and from -1139 to -1029, relative to the transcription start site, by external deletion analysis. Further detailed analysis of the region (nucleotides -1139 to -1029) most influential on the inducibility revealed that a regulatory element consisting of 10 base pairs termed a drug regulatory element (DRE) and its homologues were tandemly arranged in this region. The consensus sequence deduced from DREs is 5'-GCNTGAGGCTGGG-3'. The regulatory sequence from nucleotide -1140 to -844 is capable of conferring inducibility on a heterologous promoter in a manner independent of its orientation and distance from the subordinate promoter.
Sogawa
K
K
Fujisawa-Sehara
A
A
Yamane
M
M
Fujii-Kuriyama
Y
Y
D000123:Acetyltransferases / Q000096:biosynthesis; D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D004790:Enzyme Induction; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D008748:Methylcholanthrene / Q000494:pharmacology; D009154:Mutation; D011401:Promoter Regions, Genetic; D051381:Rats
D008748:Methylcholanthrene; D003577:Cytochrome P-450 Enzyme System; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase