title: Enhancer elements in the mouse Cyp1a2 gene for constitutive expression.
abstract: CYP1A2 is one of the major hepatic cytochrome P450s that is involved in the metabolism of many drugs, as well as in the activation of chemical carcinogens. To elucidate the transcriptional regulation of the constitutive expression of the mouse Cypla2 gene, the 4.8-kbp 5(')-flanking region of the gene was analyzed for transcriptional activity using a primary cultured mouse hepatocyte system. With 5(')- and 3(')-deletion analysis, two enhancer elements, i.e., a 20-bp DNA fragment (E1) from -4401 to -4382 and a 9-bp (E2) from -4300 to -4292, were identified. E1 and E2 contain a phorbol 12-O-tetradecanoate-13-acetate (TPA)-responsive element (TRE) and TRE-like element, respectively. Electrophoretic mobility shift assay confirmed specific binding between these two enhancer elements and nuclear proteins. Site-directed mutagenesis assay suggested that the TRE element in E1 is essential for constitutive expression of the mouse Cypla2 gene.
authors.affiliation: Department of Toxicology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, 930-0194, Toyama, Japan.
authors.forename: Yo-ichi
authors.initials: Y
authors.lastname: Uchida
authors.forename: Aiko
authors.initials: A
authors.lastname: Yano
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kumakura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sakuma
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nemoto
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D019388:Cytochrome P-450 CYP1A2 / Q000096:biosynthesis* / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D008099:Liver / Q000201:enzymology; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D014158:Transcription, Genetic
chemical_list: D008156:Luciferases; D019388:Cytochrome P-450 CYP1A2