Rhodopsin formation in Drosophila is dependent on the PINTA retinoid-binding protein

TitleRhodopsin formation in Drosophila is dependent on the PINTA retinoid-binding protein
Publication TypeJournal Article
Year of Publication2005
AuthorsWang T, Montell C
JournalJ Neurosci
Volume25
Pagination5187-94
Date Published2005 May 25
ISSN1529-2401
KeywordsAnimals, Animals, Genetically Modified, Blotting, Northern, Blotting, Western, Chromosome Mapping, Cloning, Molecular, Dose-Response Relationship, Drug, Drosophila, Drosophila Proteins, Electroretinography, Eye Proteins, Gene Expression Regulation, Developmental, Genotype, In Situ Hybridization, Light, Mutation, Pigment Epithelium of Eye, Protein Binding, Protein Structure, Tertiary, Radioligand Assay, Retinol-Binding Proteins, Rhodopsin, Sequence Alignment, Tretinoin
Abstract

Retinoids participate in many essential processes including the initial event in photoreception. 11-cis-retinal binds to opsin and undergoes a light-driven isomerization to all-trans-retinal. In mammals, the all-trans-retinal is converted to vitamin A (all-trans-retinol) and is transported to the retinal pigment epithelium (RPE), where along with dietary vitamin A, it is converted into 11-cis-retinal. Although this cycle has been studied extensively in mammals, many questions remain, including the specific roles of retinoid-binding proteins. Here, we establish the Drosophila visual system as a genetic model for characterizing retinoid-binding proteins. In a genetic screen for mutations that affect the biosynthesis of rhodopsin, we identified a novel CRAL-TRIO domain protein, prolonged depolarization afterpotential is not apparent (PINTA), which binds to all-trans-retinol. We demonstrate that PINTA functions subsequent to the production of vitamin A and is expressed and required in the retinal pigment cells. These results represent the first genetic evidence for a role for the retinal pigment cells in the visual response. Moreover, our data implicate Drosophila retinal pigment cells as functioning in the conversion of dietary all-trans-retinol to 11-cis-retinal and suggest that these cells are the closest invertebrate equivalent to the RPE.

DOI10.1523/JNEUROSCI.0995-05.2005
Alternate JournalJ. Neurosci.
PubMed ID15917458
Grant ListEY08117 / EY / NEI NIH HHS / United States