Dissection of the pathway required for generation of vitamin A and for Drosophila phototransduction

TitleDissection of the pathway required for generation of vitamin A and for Drosophila phototransduction
Publication TypeJournal Article
Year of Publication2007
AuthorsWang T, Jiao Y, Montell C
JournalJ Cell Biol
Volume177
Pagination305-16
Date Published2007 Apr 23
ISSN0021-9525
KeywordsAmino Acid Sequence, Animals, Base Sequence, beta Carotene, beta-Carotene 15,15'-Monooxygenase, Drosophila, Drosophila Proteins, Gastrointestinal Tract, Molecular Sequence Data, Neuroglia, Neurons, Receptors, Immunologic, Receptors, Scavenger, Retinaldehyde, Retinol-Binding Proteins, Rhodopsin, Scavenger Receptors, Class B, Sequence Alignment, Vision, Ocular, Vitamin A
Abstract

Dietary carotenoids are precursors for the production of retinoids, which participate in many essential processes, including the formation of the photopigment rhodopsin. Despite the importance of conversion of carotenoids to vitamin A (all-trans-retinol), many questions remain concerning the mechanisms that promote this process, including the uptake of carotenoids. We use the Drosophila visual system as a genetic model to study retinoid formation from beta-carotene. In a screen for mutations that affect the biosynthesis of rhodopsin, we identified a class B scavenger receptor, SANTA MARIA. We demonstrate that SANTA MARIA functions upstream of vitamin A formation in neurons and glia, which are outside of the retina. The protein is coexpressed and functionally coupled with the beta, beta-carotene-15, 15'-monooxygenase, NINAB, which converts beta-carotene to all-trans-retinal. Another class B scavenger receptor, NINAD, functions upstream of SANTA MARIA in the uptake of carotenoids, enabling us to propose a pathway involving multiple extraretinal cell types and proteins essential for the formation of rhodopsin.

DOI10.1083/jcb.200610081
Alternate JournalJ. Cell Biol.
PubMed ID17452532
PubMed Central IDPMC2064138
Grant ListEY08117 / EY / NEI NIH HHS / United States