Polymorphic NF-Y dependent regulation of human nicotine C-oxidase (CYP2A6).
Polymorphic NF-Y dependent regulation of human nicotine C-oxidase (CYP2A6).
复制标题
人尼古丁 C 氧化酶 (CYP2A6) 的多态性 NF-Y 依赖性调节。
DOI：
10.1097/00008571-200406000-00006
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Ingelman-Sundberg,Magnus
中科院分区：
文献类型：
--
作者：
vonRichter,Oliver;Pitarque,Marià;Rodríguez-Antona,Cristina;Testa,Anna;Mantovani,Roberto;Oscarson,Mikael;Ingelman-Sundberg,Magnus
ObjectivesIn humans, cytochrome P450 2A6 (CYP2A6) constitutes the principal nicotine C-oxidase. Several different polymorphic CYP2A6 gene variants are known which contribute to the highly variable expression of this enzyme among individuals. In this study we report a novel polymorphism located in the 5′ flanking region (− 745A> G) of the CYP2A6 gene disrupting a CCAAT box.Methods and resultsElectrophoretic mobility shift assays (EMSA) indicated that NF-Y A is part of this nuclear protein complex. Chromatin immunoprecipitation revealed that NF-Y recognizes a region of the CYP2A6 5′ flanking region located between− 932 and− 606. EMSA showed that out of the three CCAAT boxes in the CYP2A6 promoter, with CCAAT core sequences located between− 839/− 835,− 748/− 744, and− 689/− 685, only the one at− 748/− 744 was able to compete with the nuclear protein complex binding to the− 748/− 744 CCAAT box. Cotransfection experiments indicated that NF-Y acts as a positive regulatory element on CYP2A6 gene regulation. EMSA demonstrated that an NF-Y consensus oligonucleotide but not the− 745A> G oligonucleotide competed efficiently with binding of the protein complex to the− 748/− 744 CCAAT box. Promoter activity of the− 745A> G variant was significantly reduced to 78% relative to the wild-type allele in HepG2 cells transfected with luciferase reporter plasmids. Finally, haplotype analysis was carried out comprising the− 745A> G variant in combination with all known CYP2A6 3′ and 5′ flanking single nucleotide polymorphisms:− 1013A> G,− 48T> G, and the CYP2A6/CYP2A7 3′ flank conversion.ConclusionA new haplotype, CYP2A6* 1H was identified, with allele frequencies of 3.1% in Swedish and 5.2% in Turkish populations.
