title: Identification of ligands for two human bitter T2R receptors.
abstract: Earlier, a family of G protein-coupled receptors, termed T2Rs, was identified in the rodent and human genomes through data mining. It was suggested that these receptors mediate bitter taste perception. Analysis of the human genome revealed that the hT2R family is composed of 25 members. However, bitter ligands have been identified for only three human receptors so far. Here we report identification of two novel ligand-receptor pairs. hT2R61 is activated by 6-nitrosaccharin, a bitter derivative of saccharin. hT2R44 is activated by denatonium and 6-nitrosaccharin. Activation profiles for these receptors correlate with psychophysical data determined for the bitter compounds in human studies. Functional analysis of hT2R chimeras allowed us to identify residues in extracellular loops critical for receptor activation by ligands. The discovery of two novel bitter ligand-receptor pairs provides additional support for the hypothesis that hT2Rs mediate a bitter taste response in humans.
authors.affiliation: Senomyx, Inc., 11099 N. Torrey Pines Road, La Jolla, CA 92037, USA. alexey.pronin@senomyx.com
authors.forename: Alexey N
authors.initials: AN
authors.lastname: Pronin
authors.forename: Huixian
authors.initials: H
authors.lastname: Tang
authors.forename: Judy
authors.initials: J
authors.lastname: Connor
authors.forename: Walter
authors.initials: W
authors.lastname: Keung
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D015870:Gene Expression; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012439:Saccharin / Q000031:analogs & derivatives* / Q000494:pharmacology; D016415:Sequence Alignment; D018411:Spodoptera; D013649:Taste / Q000502:physiology*; D000098706:Taste Receptors, Type 2
chemical_list: D008024:Ligands; D000644:Quaternary Ammonium Compounds; D043562:Receptors, G-Protein-Coupled; D011994:Recombinant Proteins; D000098706:Taste Receptors, Type 2; C043414:denatonium; C497888:6-nitrosaccharin; D012439:Saccharin