相关实验视频
昆虫的嗅觉受体是异构体的联结体离子通道
Koji Sato1, Maurizio Pellegrino, Takao Nakagawa
1Department of Integrated Biosciences, The University of Tokyo, Chiba 277-8562, Japan.
Nature
|April 15, 2008
概括
昆虫的嗅觉受体 (ORs) 形成了与脊椎动物受体不同的新型联体激活阴离通道. 这一发现揭示了昆虫嗅觉检测和响应的独特机制.
科学领域:
- 分子生物学分子生物学
- 神经科学是一个神经科学.
- 感官生物学 感官生物学
背景情况:
- 昆虫的嗅觉感官神经元利用嗅觉受体 (ORs) 和一个保存的Or83b共受体.
- 功能性昆虫ORs形成了异构复合体,其固态度未知.
- 昆虫OR具有独特的7个跨膜拓,与脊椎动物的G蛋白合受体不同.
研究的目的:
- 为了研究异构昆虫OR复合体的功能性质.
- 为了确定昆虫OR是否作为离子通道起作用.
- 为了阐明昆虫中气味信号传导的机制.
主要方法:
- 昆虫OR复合体 (,果,蚊子) 在细胞系中的异质表达.
- 在气味刺激时测量离子流入 (Ca2+) 和离子导电.
- 来自表达Xenopus卵细胞和HEK293T细胞的贴片录音 (外向).
主要成果:
- 异构性OR复合体在被气味剂刺激时表现出细胞外Ca2+流入和非选择性离子导电性.
- 香料引起的电流独立于G蛋白合的第二信使通路.
- 快速反应动力学和OR子单元依赖的K+选择性表明OR-Or83b复合体本身形成了道.
结论:
- 昆虫ORs代表了一类新的联体激活的非选择性离子通道.
- 该OR-Or83b复合体直接形成一个气味门离子通道.
- 这种机制为昆虫提供了一种独特的策略来感知它们的嗅觉环境.
相关概念视频
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.
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Ion Channels
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Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
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Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
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Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
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The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...
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.
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