Abstract
The three members of the T1R class of taste-specific G protein-coupled receptors have been hypothesized to function in combination as heterodimeric sweet taste receptors. Here we show that human T1R2/T1R3 recognizes diverse natural and synthetic sweeteners. In contrast, human T1R1/T1R3 responds to the umami taste stimulus l-glutamate, and this response is enhanced by 5'-ribonucleotides, a hallmark of umami taste. The ligand specificities of rat T1R2/T1R3 and T1R1/T1R3 correspond to those of their human counterparts. These findings implicate the T1Rs in umami taste and suggest that sweet and umami taste receptors share a common subunit.
MeSH terms
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Amino Acid Sequence
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Animals
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GTP-Binding Proteins / physiology
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Glutamic Acid / pharmacology*
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Guanosine Monophosphate / pharmacology
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Humans
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Inosine Monophosphate / pharmacology
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Molecular Sequence Data
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Rats
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Receptors, Cell Surface / chemistry
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Receptors, Cell Surface / genetics
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Receptors, Cell Surface / physiology*
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Receptors, G-Protein-Coupled*
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Taste / physiology*
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Transfection
Substances
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Receptors, Cell Surface
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Receptors, G-Protein-Coupled
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taste receptors, type 1
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Inosine Monophosphate
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Glutamic Acid
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Guanosine Monophosphate
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GTP-Binding Proteins
Associated data
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GENBANK/AF456324
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GENBANK/AL139287
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GENBANK/AL159177
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GENBANK/BK000151
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GENBANK/BK000152
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GENBANK/BK000153