Cooperative regulation of CYP3A5 gene transcription by NF-Y and Sp family members.
The purpose of this study was to clarify the mechanism(s) responsible for the transcriptional regulation of the human CYP3A5 gene. It was found that a region from nucleotides -90 to -40 was involved in the transcriptional activity of the CYP3A5 gene by transfection of a series of 5'-truncated promoter-luciferase chimeric genes into human hepatoma HepG2 cells. A gel shift assay using nuclear extracts prepared from HepG2 cells showed that nuclear factor-Y (NF-Y) and specificity protein (Sp) 1 and Sp3 bound to CCAAT box (-78/-68) and a basic transcription element (BTE) (-67/-46) in the CYP3A5 gene. Furthermore, introduction of mutations in the CCAAT box, the BTE, or both elements decreased the transcriptional activity to 10, 21, or 4% of that seen with the intact gene. Thus, we conclude that the transcription of the CYP3A5 gene is cooperatively regulated by NF-Y, Sp1, and Sp3 in HepG2 cells.
Iwano
S
S
Laboratory of Drug Metabolism, Graduate School of Pharmaceutical Sciences, Hokkaido University, N12W6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan.
Saito
T
T
Takahashi
Y
Y
Fujita
K
K
Kamataki
T
T
D001483:Base Sequence; D023081:CCAAT-Binding Factor / Q000502:physiology*; D003001:Cloning, Molecular; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004247:DNA; D004268:DNA-Binding Proteins / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D016329:Sp1 Transcription Factor / Q000502:physiology*; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D014407:Tumor Cells, Cultured
D023081:CCAAT-Binding Factor; D004268:DNA-Binding Proteins; C497121:SP3 protein, human; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D051705:Sp3 Transcription Factor; D004247:DNA; D003577:Cytochrome P-450 Enzyme System; C104464:CYP3A protein, human; C510164:CYP3A5 protein, human; D051544:Cytochrome P-450 CYP3A