Exploring the molecular mechanisms of insect odorant receptors
Pask, Gregory Mark
Insects are able to detect a wide range of volatiles through a family of cell-surface odorant receptors (ORs), which are activated by specific odorants and relay the signal to the brain. Insect ORs function as heteromultimeric complexes consisting of an odorant-specific OR and a conserved coreceptor, Orco. Using a small molecule screen, a compound named VUAA1 was identified and characterized as an Orco agonist across several insect species. VUAA1 also served as a powerful tool in insect research to examine the structure/function relationship of several heteromeric OR complexes. In addition, a class of amiloride derivatives was identified as potent OR channel blockers and also revealed differences in function among several ORs. Finally, the molecular receptive range (MRR) of a candidate sugar-feeding receptor in Anopheles gambiae was determined and revealed aspects of the odorant-OR interaction. These studies have elucidated several aspects of insect OR function, as well as provide powerful research tools for future studies in insect olfaction.