Identification and characterization of retinoid-active short-chain dehydrogenases/reductases in Drosophila melanogaster.
BACKGROUND
In chordates, retinoid metabolism is an important target of short-chain dehydrogenases/reductases (SDRs). It is not known whether SDRs play a role in retinoid metabolism of protostomes, such as Drosophila melanogaster.


METHODS
Drosophila genome was searched for genes encoding proteins with approximately 50% identity to human retinol dehydrogenase 12 (RDH12). The corresponding proteins were expressed in Sf9 cells and biochemically characterized. Their phylogenetic relationships were analyzed using PHYLIP software.


RESULTS
A total of six Drosophila SDR genes were identified. Five of these genes are clustered on chromosome 2 and one is located on chromosome X. The deduced proteins are 300 to 406 amino acids long and are associated with microsomal membranes. They recognize all-trans-retinaldehyde and all-trans-3-hydroxyretinaldehyde as substrates and prefer NADPH as a cofactor. Phylogenetically, Drosophila SDRs belong to the same branch of the SDR superfamily as human RDH12, indicating a common ancestry early in bilaterian evolution, before a protostome-deuterostome split.


CONCLUSIONS
Similarities in the substrate and cofactor specificities of Drosophila versus human SDRs suggest conservation of their function in retinoid metabolism throughout protostome and deuterostome phyla.


CONCLUSIONS
The discovery of Drosophila retinaldehyde reductases sheds new light on the conversion of beta-carotene and zeaxantine to visual pigment and provides a better understanding of the evolutionary roots of retinoid-active SDRs.
Belyaeva
Olga V
OV
Division of Biochemistry and Molecular Genetics, School of Medicine, University of Alabama-Birmingham, 720 20th Street South, 466 Kaul Genetics Building, Birmingham, AL 35294, USA. belyaeva@uab.edu
Lee
Seung-Ah
SA
Kolupaev
Oleg V
OV
Kedishvili
Natalia Y
NY
D000429:Alcohol Oxidoreductases / Q000145:classification / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D064429:Fatty Acid Synthases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000145:classification / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012172:Retinaldehyde / Q000737:chemistry / Q000378:metabolism; D012176:Retinoids / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D013237:Stereoisomerism; D013379:Substrate Specificity
D029721:Drosophila Proteins; D007527:Isoenzymes; D011994:Recombinant Proteins; D012176:Retinoids; D000429:Alcohol Oxidoreductases; C489649:RDH12 protein, human; C036543:short chain trans-2-enoyl-CoA reductase; D009247:NADH, NADPH Oxidoreductases; D064429:Fatty Acid Synthases; D012172:Retinaldehyde