cDNA Cloning and Characterization of acis-Retinol/3α-Hydroxysterol Short-chain Dehydrogenase*
- From the Department of Biochemistry, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York 14214
Abstract
We report a mouse cDNA that encodes a 317-amino acid short-chain dehydrogenase which recognizes as substrates 9-cis-retinol, 11-cis-retinol, 5α-androstan-3α,17β-diol, and 5α-androstan-3α-ol-17-one. Thiscis-retinol/androgen dehydrogenase (CRAD) shares closest amino acid similarity with mouse retinol dehydrogenase isozymes types 1 and 2 (86 and 91%, respectively). Recombinant CRAD uses NAD+ as its preferred cofactor and exhibits cooperative kinetics for cis-retinoids, but Michaelis-Menten kinetics for 3α-hydroxysterols. Unlike recombinant retinol dehydrogenase isozymes, recombinant CRAD was inhibited by 4-methylpyrazole, was not stimulated by ethanol, and did not require phosphatidylcholine for optimal activity. CRAD mRNA was expressed intensely in kidney and liver, in contrast to retinol dehydrogenase isozymes, which show strong mRNA expression only in liver. CRAD mRNA expression was widespread (relative abundance): kidney (100) > liver (92) > small intestine (9) = heart (9) > retinal pigment epithelium and sclera (4.5) > brain (2) > retina and vitreous (1.6) > spleen (0.7) > testis (0.6) > lung (0.4). CRAD may catalyze the first step in an enzymatic pathway from 9-cis-retinol to generate the retinoid X receptor ligand 9-cis-retinoic acid and/or may regenerate dihydrotestosterone from its catabolite 5α-androstan-3α,17β-diol. These data also illustrate the multifunctional nature of short-chain dehydrogenases and provide a potential mechanism for androgen-retinoid interactions.
Footnotes
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↵* This work was supported by National Institutes of Health Grant DK47839.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 nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) .
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↵‡ To whom correspondence should be addressed: 140 Farber Hall, School of Medicine and Biomedical Sciences, 3435 Main St., SUNY-Buffalo, Buffalo, NY 14214. Tel.: 716-829-2032; Fax: 716-829-2661.
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↵1 The abbreviations and trivial names used are: RAR, retinoic acid receptor; RXR, retinoid X receptor; kb, kilobase pair(s); bp, base pair(s); CHO, Chinese hamster ovary; 3α-adiol, 5α-androstan-3α,17β-diol; androstanedione, 5α-androstan-3,17-dione; androstenedione, 4-androsten-3,17-dione; androsterone, 5α-androstan-3α-ol-17-one; CRAD,cis-retinol/androgen dehydrogenase; dihydrotestosterone, 5α-androstan-17β-ol-3-one; PCR, polymerase chain reaction; RoDH, retinol dehydrogenase; SDR, short-chain dehydrogenase/reductase; testosterone, 4-androsten- 17β-ol-3-one.
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↵2 X. Chai, Y. Zhai, and J. L. Napoli, unpublished results.
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- Received November 14, 1996.
- Revision received September 4, 1997.
