Back to Search
Start Over
Identification of Specific Ligands for Orphan Olfactory Receptors
- Source :
- Journal of Biological Chemistry. 280:11807-11815
- Publication Year :
- 2005
- Publisher :
- Elsevier BV, 2005.
-
Abstract
- Olfactory receptors are the largest group of orphan G protein-coupled receptors with an infinitely small number of agonists identified out of thousands of odorants. The de-orphaning of olfactory receptor (OR) is complicated by its combinatorial odorant coding and thus requires large scale odorant and receptor screening and establishing receptor-specific odorant profiles. Here, we report on the stable reconstitution of OR-specific signaling in HeLa/Olf cells via G protein αolf and adenylyl cyclase type-III to the Ca2+ influx-mediating olfactory cyclic nucleotide-gated CNGA2 channel. We demonstrate the central role of Gαolf in odorant-specific signaling out of OR. The employment of the non-typical G protein α15 dramatically altered the odorant specificities of 3 of 7 receptors that had been characterized previously by different groups. We further show for two OR that an odorant may be an agonist or antagonist, depending on the G protein used. HeLa/Olf cells proved suitable for high-throughput screening in fluorescence-imaging plate reader experiments, resulting in the de-orphaning of two new OR for the odorant (-)citronellal from an expression library of 93 receptors. To demonstrate the G protein dependence of its odorant response pattern, we screened the most sensitive (-)citronellal receptor Olfr43 versus 94 odorants simultaneously in the presence of Gα15 or Gαolf. We finally established an EC50-ranking odorant profile for Olfr43 in HeLa/Olf cells. In summary, we conclude that, in heterologous systems, odorants may function as agonists or antagonists, depending on the G protein used. HeLa/Olf cells provide an olfactory model system for functional expression and de-orphaning of OR.
- Subjects :
- Agonist
Olfactory receptor
biology
G protein
medicine.drug_class
Heterologous
Cell Biology
biology.organism_classification
Biochemistry
Adenylyl cyclase
HeLa
chemistry.chemical_compound
medicine.anatomical_structure
chemistry
medicine
Receptor
Molecular Biology
psychological phenomena and processes
Function (biology)
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 280
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi...........d08bb5093e65c7e8dee9de50294338ed