Complex mechanism underlying transcriptional control of the haplotyped flavin-containing monooxygenase 3 (FMO3) gene in Japanese: different regulation between mutations in 5'-upstream distal region and common element in proximal region.
We reported the human flavin-containing monooxygenase 3 (FMO3) haplotypes (Pharmacogenet. Genomics: 17, 827, 2007). The objective was to gain the insight into transcriptional regulation in a Japanese population. The wild-type FMO3 reporter plasmids carrying 5'-flanking sequence from the transcriptional initiation site of the FMO3 haplotype 1 (prepared from three individuals) showed higher luciferase activities in HepG2 cells than those from the FMO3 haplotypes 2 and 3, with the wild-type coding region. Several deletion mutants of the FMO3 haplotype 1 (extending from -5,167 to -1,764, numbered relative to the A of the ATG translational initiation codon) revealed that the region of -2,064 to -1,804 contained an important cis-acting element(s) for activation of the FMO3 gene expression. Putative hepatocyte nuclear factor-4 (HNF-4) binding site and CCAAT box, but not Yin Yang 1 element, could be responsible cis-acting elements of the FMO3 gene, by site-directed mutagenesis analysis. The unknown suppressive cis-element(s) at the 5'-upstream region from -2,064 might show genetic polymorphism, because the FMO3 haplotypes 2 and 3 had three and ten mutations, respectively. These results suggest that the putative HNF-4 binding site and CCAAT box could be responsible cis-acting elements of the FMO3 gene in Japanese.
Shimizu
Makiko
M
Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan.
Murayama
Norie
N
Nagashima
Satomi
S
Fujieda
Masaki
M
Yamazaki
Hiroshi
H
D020121:5' Untranslated Regions / Q000235:genetics*; D020816:Amino Acid Motifs / Q000235:genetics; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D045744:Cell Line, Tumor; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006239:Haplotypes / Q000235:genetics / Q000502:physiology*; D051557:Hepatocyte Nuclear Factor 4 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010105:Oxygenases / Q000235:genetics / Q000502:physiology*; D011110:Polymorphism, Genetic / Q000235:genetics; D020218:Response Elements / Q000235:genetics; D013489:Suppression, Genetic; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology*
D020121:5' Untranslated Regions; C496592:HNF4A protein, human; D051557:Hepatocyte Nuclear Factor 4; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)