A Gr receptor is required for response to the sugar trehalose in taste neurons of Drosophila.
We recently identified from the Drosophila genome database a large family of G protein-coupled receptor genes, the Gr genes, and predicted that they encode taste receptors on the basis of their structure and specificity of expression. The expression of Gr genes in gustatory neurons has subsequently been confirmed and 56 family members have been reported. Here we provide functional evidence that one Gr gene, Gr5a, encodes a taste receptor required for response to the sugar trehalose. In two different mutants that carry deletions in Gr5a, electrophysiological and behavioral responses to trehalose were diminished but the response to sucrose was unaffected. Transgenic rescue experiments showed that Gr5a confers response to trehalose. The results correlate a particular taste ligand with a Gr receptor and indicate a role for G protein-mediated signaling in the transduction of sweet taste in Drosophila.
Dahanukar
A
A
Department of Molecular, Cellular, and Developmental Biology, Yale University, PO Box 208103, New Haven, Connecticut 06520-8103, USA.
Foster
K
K
van der Goes van Naters
W M
WM
Carlson
J R
JR
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics; D001483:Base Sequence / Q000502:physiology; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D003062:Codon / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004330:Drosophila / Q000166:cytology / Q000502:physiology*; D005526:Food, Formulated; D019204:GTP-Binding Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D005786:Gene Expression Regulation / Q000502:physiology; D008040:Genetic Linkage / Q000502:physiology; D008297:Male; D009154:Mutation / Q000502:physiology*; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D010641:Phenotype; D014176:Protein Biosynthesis / Q000502:physiology; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D013395:Sucrose / Q000494:pharmacology; D013649:Taste / Q000187:drug effects / Q000502:physiology*; D014199:Trehalose / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D014960:X Chromosome / Q000235:genetics
D003062:Codon; D011956:Receptors, Cell Surface; D013395:Sucrose; D014199:Trehalose; D019204:GTP-Binding Proteins