Vertebrate odorant receptors.

Olfactory transduction begins with the binding of an odorous molecule to a protein receptor--odorant receptor--on the cell surface of olfactory neuron. Odorant receptors are encoded by a large gene family belonging to the superfamily of G-protein-coupled, seven-transmembrane-domain receptors. Since the identification of the receptor gene family in 1991, a considerable amount of progress has been made in the study of odorant receptors, including aspects of spatial and temporal expression pattern, the genomic organization of the receptor genes, regulation of expression, and receptor function. These studies are of critical importance in understanding how the olfactory system recognizes and distinguishes thousands of odors.