A protein molecule that resides on the cell surface of an olfactory receptor neuron (q.v.) and which binds an odorant (q.v.). Odorant receptors are encoded by distinct families of odorant receptor genes, which encode G protein–coupled receptors (GPCRs) (q.v.). The binding of an odorant to an odorant receptor (q.v.) causes a structural change in the latter, which leads to the activation of the G protein (q.v.) attached to it. The G protein then causes the activation of different intracellular signaling events, which result in the production of an electrical impulse that is transmitted to specific regions of the brain via nerve processes. Here the information from different types of odorant receptors is sorted out, and specific odors are perceived by the organism. Also called olfactory receptor. See Chronology, 1991, Buck and Axel; cellular signal transduction, G protein-coupled receptors, G proteins, odorant receptor gene.
Subjects: Genetics and Genomics — Chemistry.