Functional properties of insect olfactory receptors: ionotropic receptors and odorant receptors

The majority of insect olfactory receptors belong to two distinct protein families, the ionotropic receptors (IRs), which are related to the ionotropic glutamate receptor family, and the odorant receptors (ORs), which evolved from the gustatory receptor family. Both receptor types assemble to heteromeric ligand-gated cation channels composed of odor-specific receptor proteins and co-receptor proteins. We here present in short the current view on evolution, function, and regulation of IRs and ORs. Special attention is given on how their functional properties can meet the environmental and ecological challenges an insect has to face.

Automated summary

The majority of insect olfactory receptors belong to two distinct protein families - ionotropic receptors (IRs) related to the ionotropic glutamate receptor family, and odorant receptors (ORs) evolved from the gustatory receptor family. Both types assemble into heteromeric ligand-gated cation channels, addressing environmental and ecological challenges insects face.