Abstract: Newly identified mammalian taste-cell-specific G protein-coupled receptors, and the genes and cDNA encoding said receptors are described. Specifically, T1R G protein-coupled receptors active in taste signaling, and the genes and cDNA encoding the same, are described, along with methods for isolating such genes and for isolating and expressing such receptors. Methods for representing taste perception of a particular taste stimulus in a mammal are also described, as are methods for generating novel molecules or combinations of molecules that elicit a predetermined taste perception in a mammal, and methods for simulating one or more tastes. Further, methods for stimulating or blocking taste perception in a mammal are also disclosed.

Abstract: Binding assays for identifying ligands that modulate human T1R3 polypeptide-associated taste are disclosed. These assays detect the specific binding of compounds to a human T1R3 polypeptide or the modulation of the specific binding of another compound that specifically binds human T1R3 polypeptide. The binding assays may include the use of detectable labels, e.g., radionuclides, enzymes, fluorophores, and the like. Compounds identified in these binding assays have potential application as T1R3 taste modulators and therefore potentially are useful additives in compositions for human or animal consumption.

Abstract: The invention relates to compounds that specifically bind a T1R1/T1R3 or T1R2/T1R3 receptor or fragments or sub-units thereof. The present invention also relates to the use of hetero-oligomeric and chimeric taste receptors comprising T1R1/T1R3 and T1R2/T1R3 in assays to identify compounds that respectively respond to umami taste stimuli and sweet taste stimuli. Further, the invention relates to the constitutive of cell lines that stably or transiently co-express a combination of T1R1 and T1R3; or T1R2 and T1R3; under constitutive or inducible conditions. The use of these cells lines in cell-based assays to identify umami and sweet taste modulatory compounds is also provided, particularly high throughput screening assays that detect receptor activity by use of fluorometric imaging.

Abstract: The invention provides a series of chimeric G?15 protein variants that couple to certain GPCRs more efficiently than the native G?15 protein. These chimeric G?15 protein variants can be used to discover and analyze modulators of GPCRs (especially those that mediate taste perception).

Abstract: Functional assays for identifying compounds that activate or modulate the activation of the T1R1/T1R3 (umami) taste receptor are provided. These assays detect the effect of one or more compounds on the activation of T1R1/T1R3 (umami) taste receptor or on the activation of T1R1/T1R3 umami taste receptor by another compound e.g., monosodium glutamate, lactisole, or another unami taste modulator. These assays preferably are cell-based functional assays and typically use cells, e.g., HEK-293 cells that express a G protein such as G?15, G?16 or gustducin. Compounds identified in the disclosed functional assays are potentially useful as flavor additives in compositions for human or animal consumption.

Abstract: Screening assays, preferably high throughput, are provided that screen libraries of candidate compounds to identify agonists, antagonists, enhancers or modulators of taste receptors (bitter, sweet or savory (umami) taste receptor) using test cells that co-express at least one functional taste receptor and an olfactory cyclic nucleotide-gated channel (oCNGC). (The oCNGC preferably comprises at least one mutation in one or more subunits that renders the resultant oCNGC more sensitive to CAMP (which in turn enhances the sensitivity of assay using this oCNGC). These taste modulatory compounds are identified based on their effect on oCNGC activity, e.g., using fluorimetric assays that screen for changes in intracellular calcium or sodium concentration in test cells that co-express at least one taste receptor, oCNGC and a G?i/o protein.

Abstract: Isolated or biologically pure taste receptors comprised of at least one T1R2 and T1R3 polypeptide and compositions containing are provided. These taste receptors specifically bind and/or are specifically activated by sweet taste stimuli such as natural and artificial sweetener compounds. These taste receptors are useful in screening assays for identifying compounds that elicit or modulate (enhance or inhibit) sweet taste. These compounds can be used as additives and flavorants to improve the taste of compositions for human or animal consumption. In preferred embodiments, the T1R2/T1R3 receptor will be comprised of human T1R2/human T1R3 expressed in association with a suitable G protein, preferably G?15.

Abstract: The present invention relates to isolated nucleic acid sequences that encode human olfactory cyclic nucleotide gated (CNG) channel subunits, and the corresponding polypeptides. The invention further relates to the use of human CNG channels to profile, screen for, and identify compounds that modulate the human olfactory CNG channel. More specifically, the invention relates to the expression of the human olfactory CNG channel in cells, preferably mammalian cells, and the use of these cells in high throughput cell-based assays to identify compounds that enhance or block human olfactory CNG function. Compounds that activate the olfactory CNG channel will enhance smell and can be used to make foods more palatable for individuals with attenuated olfactory function. Conversely, compounds that inhibit the olfactory CNG channel will inhibit smell and can be use to block malodors.

Abstract: Functional assays for identifying compounds that activate or modulate the activation of the T1R2/T1R3 (sweet) taste receptor are provided. These assays detect the effect of one or more compounds on the activation of T1R2/T1R3 (sweet) taste receptor or on the activation of T1R2/T1R3 sweet taste receptor by another, compound e.g., saccharin or another artificial or natural sweetener. These assays preferably are cell-based functional assays and typically use cells, e.g., HEK-293 cells that stably express a G protein such as G?15, G?16 or gustducin. Compounds identified in the disclosed functional assays are potentially useful as additives in compositions for human or animal consumption.

Abstract: Newly identified mammalian taste-cell-specific G protein-coupled receptors which function as hetero-oligomeric complexes in the sweet taste transduction pathway, and the genes and cDNA encoding said receptors are described. Specifically, T1R G protein-coupled receptors active in sweet taste signaling as hetero-oligomeric complexes, and the genes and cDNA encoding the same, are described, along with methods for isolating such genes and for isolating and expressing such receptors. Methods for identifying putative taste modulating compounds using such hetero-oligomeric complexes also described, as is a novel surface expression facilitating peptide useful for targeting integral plasma membrane proteins to the surface of a cell.

Abstract: Newly identified mammalian taste-cell-specific G protein-coupled receptors which function as hetero-oligomeric complexes in the sweet taste transduction pathway, and the genes and cDNA encoding said receptors are described. Specifically, T1R G protein-coupled receptors active in sweet taste signaling as hetero-oligomeric complexes, and the genes and cDNA encoding the same, are described, along with methods for isolating such genes and for isolating and expressing such receptors. Methods for identifying putative taste modulating compounds using such hetero-oligomeric complexes also described, as is a novel surface expression facilitating peptide useful for targeting integral plasma membrane proteins to the surface of a cell.

Abstract: Binding assays for identifying compounds that induce or modulate the T1R1/T1R3 (umami) receptor-associated taste are provided. These binding assays detect the specific binding of a compound to a T1R1/T1R3 (umami) taste receptor or detect the modulation (inhibition or enhancement) of the binding of another compound, e.g., L-glutamate, L-aspartate or lactisole to a T1R1/T1R3 umami taste receptor. Compounds that are identified in these binding assays have potential application as T1R1/T1R3 umami taste modulators and therefore can be used as flavor additives in compositions for human or animal consumption.

Abstract: The invention provides a series of chimeric G?15 protein variants that couple to certain GPCRs more efficiently than the native G?15 protein. These chimeric G?15 protein variants can be used to discover and analyze modulators of GPCRs (especially those that mediate taste perception).

Abstract: Binding assays for identifying compounds that modulate human T1R2 polypeptide associated taste are disclosed. These assays detect the specific binding of compounds to a human T1R2 polypeptide or the modulation of the specific binding of a compound that specifically binds to a human T1R2 polypeptide. The binding assays may include the use of detectable labels, e.g., radionuclides, enxymes, fluorophases, and the like. Compounds identified in these binding assays have putative application as T1R2 taste modulators, particularly sweet taste, and potentially are useful additives in compositions for human or animal consumption.

Abstract: The invention provides a series of chimeric Ga15 protein variants that couple to certain GPCRs more efficiently than the native Ga15 protein. These chimeric Ga15 protein variants can be used to discover and analyze modulators of GPCRs (especially those that mediate taste perception).

Abstract: Binding assays for identifying ligands that modulate human T1R3 polypeptide-associated taste are disclosed. These assays detect the specific binding of compounds to a human T1R3 polypeptide or the modulation of the specific binding of another compound that specifically binds human T1R3 polypeptide. The binding assays may include the use of detectable labels, e.g., radionuclides, enzymes, fluorophores, and the like. Compounds identified in these binding assays have potential application as T1R3 taste modulators and therefore potentially are useful additives in compositions for human or animal consumption.

Abstract: Functional assays that use hT1R2 receptor polypeptides to screen for taste modulatory compounds are provided. In preferred embodiments these assays will use cells that stably or transiently express an hT1R2 polypeptide and which further express a suitable protein, e.g. G&agr;15, G&agr;16 or gustducin. Such functional assays will screen for the effect of compound on T1R2 activity by detecting changes in cell voltage, intracellular ions, phosphorylation, second messenger levels and the like. Compounds identified in such assays are potentially useful as taste modulators. In preferred embodiments, the effect of selected compounds is evaluated further in human taste tests.

Abstract: Methods for expressing a functional heteromeric taste receptor that responds to sweet taste stimuli are provided. These methods comprise the co-expression of T1R2 and T1R3 nucleic acid sequences in a host cell that desirably further expresses a G protein that couples therewith, e.g., G&agr;15, G&agr;16 or gustducin. In preferred embodiments, the host cells will be mammalian cells or Xenopus oocytes. These nucleic acid sequences are expressed constitutively or under inducible conditions. In preferred embodiments the expression methods will use HEK-293 cells that also stably express G&agr;15. These methods give rise to heteromeric receptors and compositions containing that are useful in assays for identifying novel sweeteners and sweetness modulators.

Abstract: Binding assays for identifying components that modulate human T1R1 polypeptide-associated taste are disclosed. These assays detect the specific binding of compounds to a human T1R1 polypeptide or the modulation of the specific binding of another compound that specifically binds human T1R1 polypeptide. The binding assays may include the use of detectable labels, e.g., radionuclides, enxymes, fluorophores, and the like. Compounds identified in these binding assays have potential application as T1R1 taste modulators and can be used as additives in compositions for human or animal consumption.

Abstract: The present invention relates to the discovery that the T1R receptors assemble to form functional taste receptors. Particularly, it has been discovered that co-expression of T1R1 and T1R3 results in a taste receptor that responds to umami taste stimuli, including monosodium glutamate. Also, it has been discovered that co-expression of the T1R2 and T1R3 receptors results in a taste receptor that responds to sweet taste stimuli including naturally occurring and artificial sweeteners.