Transcriptional Regulation of the CYP2C12 Gene in Female Rats.

Accession number;00A0997671
Title;Transcriptional Regulation of the CYP2C12 Gene in Female Rats.
Author; TAKAHASHI YOSHIKI (Hokkaido Univ., Grad. Sch.) SASAKI YASUMASA (Hokkaido Univ., Grad. Sch.) KAMATAKI TETSUYA (Hokkaido Univ., Grad. Sch.)
Journal Title;Xenobiotic Metabolism and Disposition
Journal Code:X0758A
ISSN:0916-1139
VOL.15;NO.Supplement;PAGE.S90-S91(2000)
Figure&Table&Reference;FIG.1, REF.1
Pub. Country;Japan
Language;Japanese
Abstract;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 (GAS), known to be recognized by the signal transducer and activator of transcription (STAT) proteins. In fact, a super shift assay showed that STAT5 was capable of binding to the core sequence of the GHRE. Furthermore, a luciferase assay with reporter plasmids, which lacks HNF4- or HNF6-binding sites, revealed that the GH-stimulated expression of the CYP2C12 gene was regulated cooperatively by STAT5, HNF-4, HNF-6 and the factor(s) which 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. (author abst.)