Functional identification of a goldfish odorant receptor

The vertebrate olfactory system utilizes odorant receptors to receive and d iscriminate thousands of different chemical stimuli. An understanding of ho w these receptors encode information about an odorant's molecular structure requires a characterization of their ligand specificities. We employed an expression cloning strategy to identify a goldfish odorant receptor that is activated by amino acids - potent odorants for fish. Structure-activity an alysis indicates that the receptor is preferentially tuned to recognize bas ic amino acids. The receptor is a member of a multigene family of G protein -coupled receptors, sharing sequence similarities with the calcium sensing, metabotropic glutamate, and V2R class of vomeronasal receptors. The ligand tuning properties of the goldfish amino acid odorant receptor provide info rmation for unraveling the molecular mechanisms underlying olfactory coding .