Mouse P450RAI (CYP26) Expression and Retinoic Acid-inducible Retinoic Acid Metabolism in F9 Cells Are Regulated by Retinoic Acid Receptor γ and Retinoid X Receptor α

doi:10.1074/jbc.273.4.2409

Mouse P450RAI (CYP26) Expression and Retinoic Acid-inducible Retinoic Acid Metabolism in F9 Cells Are Regulated by Retinoic Acid Receptor γ and Retinoid X Receptor α*

From the ^‡Cancer Research Laboratories and the Departments of ^§Pathology, ^‖Biochemistry, and ^§§Medicine, Queen’s University, Kingston, Ontario K7L 3N6, Canada and ^**Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/Université Louis Pasteur, Collège de France, BP 163, 67404 Illkirch-Cédex, France

Abstract

We have cloned a mouse cDNA homolog of P450RAI, a cytochrome P450 belonging to a new family (CYP26), which has previously been isolated from zebrafish and human cDNAs and found to encode a retinoic acid-inducible retinoic acid hydroxylase activity. The cross-species conservation of the amino acid sequence is high, particularly between the mouse and the human enzymes, in which it is over 90%. Like its human and zibrafish counterparts, the mouse P450RAI cDNA catalyzes metabolism of retinoic acid into 4-OH-retinoic acid, 4-oxo-retinoic acid, 18-OH-retinoic acid, and unidentified water-soluble metabolites when transfected into COS-1 cells. Retinoic acid-inducible retinoic acid metabolism has previously been observed in F9 murine embryonal carcinoma cells and some derivatives lacking retinoid receptors. We were interested in determining whether P450RAI could be responsible for retinoic acid metabolism in F9 cells and in studying the effect of retinoid receptor ablation on P450RAIexpression. In wild-type F9 cells and derivatives lacking RARγ, RARα, and/or RXRα, we observed a direct relationship between the level of retinoic acid metabolic activity and retinoic acid-induced P450RAI mRNA. These experiments, as well as others using synthetic receptor subtype-specific retinoids, suggest that the RARγ and RXRα receptors mediate the effects of retinoic acid on the expression of theP450RAI gene.

Footnotes

↵* This work was supported by grants from by the Medical Research Council of Canada (to M. P. and G. J.).The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¶ The contribution of these authors to the work was equal.
↵‡ Supported by fellowships from the Center National de la Recherche Scientifique and the Fondation pour la Recherche Médicale.
↵¶¶ Supported by funds from CNRS, INSERM, the Collège de France, the Center Hospitalier Universitaire Régional, the Association pour la Recherche sur le Cancer, the Fondation pour la Recherche Médicale, the Human Frontier Science Program, and Bristol-Myers Squibb.
↵166 To whom correspondence should be addressed: Cancer Research Laboratories, Rm. 355, Botterell Hall, Queen’s University, Kingston, Ontario K7L 3N6, Canada. Tel.: 613-545-6791; Fax: 613-545-6830; E-mail: petkovic{at}post.queensu.ca.
↵1 The abbreviations used are: RA, retinoic acid; 4-OH-RA, 4-hydroxy-RA; 18-OH-RA, 18-hydroxy-RA; RAR, RA receptor; RXR, retinoid X receptor; HPLC, high performance liquid chromatography; RT-PCR, reverse transcriptase polymerase chain reaction.
↵2 Chiba, H., Clifford, J., Metzger, D., and Chambon, P. (1997) J. Cell Biol. 139, 735–747.
↵3 B. Beckett, J. White, and M. Petkovich, unpublished observations.
↵4 White, J. A., Beckett, B., Scherer, S. W., Herbrick, J.-A., and Petkovich, M. (1998) Genomics, in press.
↵5 A. Iulianella, D. Lohnes, L. Luu, K. Hsu, B. R. Beckett, and M. Petkovich, unpublished results.
- Received July 8, 1997.
- Revision received October 8, 1997.
The American Society for Biochemistry and Molecular Biology, Inc.