Related Experiment Videos
Characterization of a rabbit gene encoding a clofibrate-inducible fatty acid omega-hydroxylase: CYP4A6
A S Muerhoff1, K J Griffin, E F Johnson
1Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037.
Abstract:
CYP4A6 mRNAs are induced in the rabbit liver and kidney following treatment with the antihyperlipidemic drug clofibrate. As a first step toward the elucidation of the mechanism controlling the induction of this and other CYP4A genes by clofibrate and other peroxisome proliferators, we have cloned and characterized the CYP4A6 gene. Genomic DNA containing the first 12 exons encoding CYP4A6 was isolated as three recombinant lambda phage, two of which were overlapping. The sequence of more than 1000 bp of the 5' upstream region as well as of the first 12 exons has been determined. These 12 exons encode all but approximately 80 bp at the 3' terminus of CYP4A6. Intron/exon junctions within the coding region of the gene are conserved relative to the rat CYP4A1 and CYP4A2 genes. Primer extension analysis indicates that transcription is initiated 33 bp upstream of the start codon. The CYP4A6 promoter region, like that of the rat CYP4A1 and CYP4A2 genes, does not contain a consensus TATA box. However, a consensus Sp1 recognition element is apparent at -46 bp upstream of the transcription start site. In addition, a sequence related to one of two regulatory elements that control the induction of the rat acyl-CoA oxidase gene by ciprofibrate is present upstream of the CYP4A6 promoter.
Insights
Researchers cloned and characterized the CYP4A6 gene to understand how clofibrate induces CYP4A6 mRNA in rabbits. They identified key promoter elements, including an Sp1 site, crucial for gene regulation.
Area of Science:
- Molecular Biology
- Pharmacology
- Genetics
Background:
- CYP4A6 mRNA is upregulated in rabbit liver and kidney by clofibrate, an antihyperlipidemic drug.
- Understanding the induction mechanism of CYP4A genes by peroxisome proliferators is crucial.
Purpose of the Study:
- To clone and characterize the rabbit CYP4A6 gene.
- To investigate the regulatory elements controlling CYP4A6 gene induction by clofibrate.
Main Methods:
- Cloning of CYP4A6 gene from rabbit genomic DNA using lambda phage.
- DNA sequencing of the 5' upstream region and first 12 exons.
- Primer extension analysis to determine transcription start site.
Main Results:
- The CYP4A6 gene was cloned, and its 5' upstream region and first 12 exons were sequenced.
- Transcription initiation site was identified 33 bp upstream of the start codon.
- The promoter lacks a TATA box but contains an Sp1 recognition element and a peroxisome proliferator-responsive element-like sequence.
Conclusions:
- The characterized CYP4A6 gene provides a basis for studying clofibrate-induced gene expression.
- The identified regulatory elements, including the Sp1 site, are likely involved in the transcriptional control of CYP4A6 induction.