Localization of estradiol-responsive region in the phenobarbital-responsive enhancer module of mouse Cyp2b-10 gene.
The mouse Cyp2b-10 gene is inducible by treatment with estradiol as well as so-called phenobarbital (PB)-like inducers. To identify 5'-flanking elements responsible for induction by estradiol, we carried out reporter gene assays using a primary mouse hepatocyte culture system. Cyp2b-10 gene-driven luciferase activities were induced by estradiol as well as PB in this system. Deletion analysis demonstrated that the sequence contained within the region from -2331 bp to -2281 bp was responsible for the estradiol-induced luciferase activity. This region corresponds to the core element of PB-responsive enhancer module (PBREM). Several nucleotide mutations in the putative binding sites of the PBREM core element showed that the NR1 site was required for estradiol induction, and the same element was required for PB induction. These results indicate that estradiol induces Cyp2b-10 gene expression via PBREM.
Yamamoto
M
M
Department of Toxicology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama, 930-0194, Japan.
Sakuma
T
T
Ichimaru
H
H
Nemoto
N
N
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D001483:Base Sequence; D018929:Cell Culture Techniques; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D000072467:Cytochrome P450 Family 2; D018274:Electroporation; D004742:Enhancer Elements, Genetic / Q000187:drug effects*; D004790:Enzyme Induction; D004958:Estradiol / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D017930:Genes, Reporter / Q000187:drug effects; D022781:Hepatocytes; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010634:Phenobarbital / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion; D013250:Steroid Hydroxylases
D004958:Estradiol; D003577:Cytochrome P-450 Enzyme System; D008156:Luciferases; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C101679:Cyp2b10 protein, mouse; D000072467:Cytochrome P450 Family 2; D010634:Phenobarbital