| Project/Area Number |
11680661
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TOUHARA Kazushige Associate Professor Department of Integrated Bioscience, The University of Tokyo, 大学院・新領域創成科学研究科, 助教授 (00280925)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2000: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1999: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | odorant / receptor / olfactory / 可視化 |
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| Research Abstract |
The vertebrate olfactory system discriminates a wide variety of odorants by relaying coded information from olfactory sensory neurons in the olfactory epithelium to olfactory cortical areas of the brain. Recent studies have shown that the first step in odor discrimination is mediated by approximately one thousand distinct olfactory receptors, which comprise the largest family of G protein-coupled receptors. In the present study, we used Ca^<2+> imaging techniques to functionally clone and reconstitute structurally-related mouse olfactory receptors that bind overlapping sets of odorants with distinct affinities and specificities. Our results provide direct evidence for the existence of a receptor code in which the identities of different odorants are specified by distinct combinations of odorant receptors that possess unique molecular receptive ranges. We further demonstrate that the receptor code for an odorant changes with odorant concentration. Finally, we show that odorant receptors in HEK293T cells couple to stimulatory G proteins such as Gαolf, resulting in odorant-dependent increases in cAMP.Odor discrimination is thus determined by differences in the receptive ranges of the odorant receptors that together encode specific odorant molecules.
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