Organization and function of a dioxin-responsive enhancer.
The dioxin-responsive enhancer upstream of the CYP1A1 gene contains four copies of the recognition motif for the liganded Ah receptor. The results of deletion analyses, linker-scanning analyses, and the analysis of individual enhancer subdomains reveal that each copy of the motif contributes to the response of the enhancer to 2,3,7,8-tetrachlorodibenzo-p-dioxin. In the context of the dioxin-responsive enhancer, a GC box, representing the DNA binding site for Sp1 (or a related transcription factor), has no detectable intrinsic activity but enhances gene expression when linked to a recognition motif for the liganded Ah receptor, thereby producing a synergistic effect on enhancer function.
Fisher
J M
JM
Department of Pharmacology, Stanford University School of Medicine, California 94305.
Wu
L
L
Denison
M S
MS
Whitlock
J P
JP
D000818:Animals; D001483:Base Sequence; D002872:Chromosome Deletion; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004147:Dioxins / Q000494:pharmacology*; D004742:Enhancer Elements, Genetic / Q000187:drug effects*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D008969:Molecular Sequence Data; D009154:Mutation; D015345:Oligonucleotide Probes; D010957:Plasmids; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug / Q000235:genetics / Q000378:metabolism; D015183:Restriction Mapping
D004147:Dioxins; D015345:Oligonucleotide Probes; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug; D003577:Cytochrome P-450 Enzyme System