The Retinal Pigment Epithelial-specific 11-cis Retinol Dehydrogenase Belongs to the Family of Short Chain Alcohol Dehydrogenases (*)
- From the (1)Ludwig Institute for Cancer Research, Stockholm Branch, Box 240, S-171 77, Stockholm, Sweden and the
- (2)Ludwig Institute for Cancer Research, Uppsala Branch, Biomedical Centre, S-751 22, Uppsala, Sweden
- § To whom correspondence should be addressed. Tel.: 46-8-7287109; Fax: 46-8-332812.
Abstract
We have isolated and partially characterized a 32-kDa membrane-associated protein (p32), which forms a complex with p63, an
abundant membrane protein in bovine retinal pigment epithelium. The sequence of a cDNA clone for p32 revealed an open reading
frame encoding 318 amino acid residues. Several hydrophobic regions could be identified, suggesting that p32 is an integral
membrane protein. A search of data bases identified p32 as a member of the superfamily of short chain alcohol dehydrogenases.
Transcripts for p32 were specifically expressed in retinal pigment epithelium. Overexpression of p32 in Cos cells produced
a membrane-bound stereospecific 11-cis retinol dehydrogenase, active in the presence of NAD
as cofactor but not in the presence of NADP. We propose that p32 is the stereospecific 11-cis retinol dehydrogenase, which catalyzes the final step in the biosynthesis of 11-cis retinaldehyde, the universal chromophore of visual pigments.
Footnotes
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↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by 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(TM)/EMBL Data Bank with accession number(s) X82262[GenBank].
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↵1 The abbreviations used are:
- RPE
-
retinal pigment epithelium
- CHAPS
-
3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate
- PBS
-
phosphate-buffered saline
- PCR
-
polymerase chain reaction
- SCAD
-
short chain alcohol dehydrogenase
- PAGE
-
polyacrylamide gel electrophoresis
- bp
-
base pair(s)
- kb
-
kilobase(s)
- HPLC
-
high performance liquid chromatography.
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- Received June 16, 1994.
- Revision received November 7, 1994.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
