A class B scavenger receptor mediates the cellular uptake of carotenoids in Drosophila.
Carotenoids are currently being intensely investigated regarding their potential to lower the risk of chronic disease and vitamin A deficiency. Invertebrate models in which vitamin A deficiency is not lethal allow the isolation of blind but viable mutants affected in the pathway leading from dietary carotenoids to vitamin A. Using a mutant in one of these model systems, Drosophila, the vitamin A-forming enzyme has recently been molecularly identified. We now show that the molecular basis for the blindness of a different Drosophila mutant, ninaD, is a defect in the cellular uptake of carotenoids. The ninaD gene encodes a class B scavenger receptor essential for the formation of the visual chromophore. A loss of this function results in a carotenoid-free and thus vitamin A-deficient phenotype. Our investigations provide molecular insight into how carotenoids may be distributed into cells of target tissues in animals and indicate a crucial role of class B scavenger receptors rendering dietary carotenoids available for subsequent cell metabolism, as needed for their various physiological functions.
Institute of Biology I, Neurobiology, and Animal Physiology, Albert-Ludwig University of Freiburg, Hauptstrasse 1, D-79104 Freiburg, Germany. johannes.von.lintig@biologie.uni-freiburg.de
Cornelia
C
Kiefer
Emerich
E
Sumser
Mathias F
MF
Wernet
Johannes
J
Von Lintig
D000483:Alleles; D000818:Animals; D018955:CD36 Antigens; D002338:Carotenoids / Q000378:metabolism*; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D050356:Lipid Metabolism; D008565:Membrane Proteins; D010641:Phenotype; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D018110:Receptors, Lipoprotein / Q000235:genetics / Q000378:metabolism*; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D014170:Transformation, Genetic
D018955:CD36 Antigens; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D019476:Insect Proteins; D008565:Membrane Proteins; C465435:NinaD protein, Drosophila; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D002338:Carotenoids