Abstract
Taste receptor cells (TRCs) express multiple umami receptors. We performed physiological investigations to determine whether umami-responding cells in taste buds possess G protein-coupled receptors and to determine what type of G proteins exist if any. To clarify the components that participate in intracellular umami signal transduction in mouse, we recorded the activation of TRCs. TRCs treated with the G protein inhibitor GDP-beta-S lost umami-induced inward currents. Treatment with the Galphai inhibitor, pertussis toxin, did not increase the intracellular Ca2+ level in many TRCs. Immunohistochemical analysis revealed that a subset of TRCs responding to umami stimuli expressed alpha-gustducin. Thus, we demonstrated that umami stimuli were received by G protein-coupled receptors that function together with some of the Galphai family members.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Calcium / metabolism
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Electrophysiology
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Female
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GTP-Binding Protein alpha Subunits / physiology
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GTP-Binding Proteins / antagonists & inhibitors
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GTP-Binding Proteins / physiology
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Guanosine Diphosphate / analogs & derivatives
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Guanosine Diphosphate / pharmacology
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Heterotrimeric GTP-Binding Proteins / analysis
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Heterotrimeric GTP-Binding Proteins / physiology
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Immunochemistry
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Mice
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Mice, Inbred C57BL
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Patch-Clamp Techniques
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Pertussis Toxin / pharmacology
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Receptors, G-Protein-Coupled / physiology*
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Signal Transduction / drug effects
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Signal Transduction / physiology*
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Taste / physiology
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Taste Buds / cytology
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Taste Buds / metabolism
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Taste Buds / physiology*
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Thionucleotides / pharmacology
Substances
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GTP-Binding Protein alpha Subunits
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Receptors, G-Protein-Coupled
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Thionucleotides
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taste receptors, type 1
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Guanosine Diphosphate
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guanosine 5'-O-(2-thiodiphosphate)
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Pertussis Toxin
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GTP-Binding Proteins
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GNAT3 protein, mouse
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Heterotrimeric GTP-Binding Proteins
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Calcium