Cooperative regulation of CYP2C12 gene expression by STAT5 and liver-specific factors in female rats.
The purpose of this study was to clarify the mechanism(s) responsible for the growth hormone (GH)-induced expression of the CYP2C12 gene. To identify a functional GH-responsive element (GHRE) in vivo, we performed the direct injection of promoter-luciferase chimeric genes into female rat livers. The results showed that the luciferase activity was decreased to approximately 20% by the deletion of the sequence between nucleotides -4213 and -4161. Within this region, two copies of a possible GHRE were present. The sequence of the GHRE was overlapped with that of an interferon-gamma-activated sequence, known to be recognized by the signal transducer and activator of transcription (STAT) proteins. In fact, a supershift assay showed that STAT5 was capable of binding to the core sequence of the GHRE. Furthermore, a luciferase assay with reporter plasmids, Delta-4161/-3781, mutated hepatocyte nuclear factor-4 (HNF-4), and mutated HNF-6, revealed that the GH-stimulated expression of the CYP2C12 gene was regulated cooperatively by STAT5, HNF-4, HNF-6, and the factor(s) that binds to the elements, 2C12-I (-4095 to -4074) and 2C12-II (-4072 to -4045). The cooperative regulation by STAT5 and the liver-enriched transcription factors account for the GH-dependent and the liver-specific expression of the CYP2C12 gene in female rats.
Sasaki
Y
Y
Laboratory of Drug Metabolism, Division of Pharmacobiodynamics, Graduate School of Pharmaceutical Sciences, Hokkaido University, N12W6, Kita-ku, Sapporo, Hokkaido 060-0812, Japan.
Takahashi
Y
Y
Nakayama
K
K
Kamataki
T
T
D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D013006:Growth Hormone / Q000494:pharmacology; D051557:Hepatocyte Nuclear Factor 4; D051559:Hepatocyte Nuclear Factor 6; D018398:Homeodomain Proteins / Q000502:physiology*; D008894:Milk Proteins; D010750:Phosphoproteins / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020218:Response Elements; D050799:STAT5 Transcription Factor; D013250:Steroid Hydroxylases / Q000235:genetics*; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
D004268:DNA-Binding Proteins; D051557:Hepatocyte Nuclear Factor 4; D051559:Hepatocyte Nuclear Factor 6; D018398:Homeodomain Proteins; D008894:Milk Proteins; C496607:Onecut1 protein, rat; D010750:Phosphoproteins; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D013006:Growth Hormone; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; C034694:steroid 15-beta-hydroxylase