関連する実験動画
Updated: Jul 28, 2026

07:10
Taste Exam: A Brief and Validated Test
Published on: August 17, 2018
苦い味と甘い味の変換は,グストドゥチンによって行われます
G T Wong1, K S Gannon, R F Margolskee
1Department of Physiology and Biophysics, Mount Sinai School of Medicine, New York 10029, USA.
Nature
|June 27, 1996
まとめ
味覚受容体細胞の重要なGタンパク質であるガストドゥチンは,苦味と甘味の両方の味覚信号伝達を媒介する. アルファ・グストドゥシンが欠けていたマウスは,苦味と甘味の化合物に対する反応が低下し,その重要な役割が確認されました.
科学分野:
- 神経科学は神経科学である.
- 分子生物学は分子生物学である.
- 感覚生物学 感覚生物学について
背景:
- 甘くて苦い味の知覚には,Gタンパク質結合受容体が関与しています.
- 味覚受容体細胞特異のGタンパク質であるガストドゥチンは,苦い味の伝達に関与しています.
- Rod transducinは味覚受容体細胞にも存在し,苦い受容体と相互作用する可能性があります.
研究 の 目的:
- 味覚信号伝達におけるガストドゥチンの役割を調査する.
- アルファ-グストドゥチンサブユニットに欠けているマウスの味覚反応を特徴付けるために.
主な方法:
- アルファ-グストドゥチンのノックアウトマウスの生成と特徴付け.
- 甘い,苦い,塩味,酸味の化合物に対する味覚反応の行動分析.
- ミュータントマウスと野生型のマウスの味覚反応の電気生理学的記録.
主要な成果:
- アルファ-グストドゥチン欠乏症のマウスは,苦い化合物に対する行動的および電気生理学的反応が低下した.
- 塩酸刺激に対する反応は,対照群と比較して,突然変異したマウスでは影響を受けなかった.
- ミュータントマウスは,最初の予測に反して,甘い化合物に対する反応が低下したことも示した.
結論:
- グストドゥチンは,苦い味と甘い味の両方の味覚信号伝達の主な媒介である.
- この発見は,苦い味の知覚を超えて,グストドゥチンの既知の機能を拡張しています.
関連する概念動画
G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
Gustation
Gustation is a chemical sense that, along with olfaction (smell), contributes to our perception of taste. It starts with the activation of receptors by chemical compounds (tastants) dissolved in the saliva. The saliva and filiform papillae on the tongue distribute the tastants and increase their exposure to the taste receptors.
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
The Physiology of Taste
The perception of a salty flavor is facilitated by sodium ions within the oral salivary fluid. Upon consumption of a salty substance, salt crystals disassemble, leading to the liberation of its constituents—Na+ and Cl- ions. These ions subsequently dissolve into the salivary fluid present in the oral cavity. The external environment of the gustatory cells experiences an elevation in Na+ concentration, thereby establishing a potent concentration gradient. This gradient propels the diffusion of...

