门通道的晶体结构和机制
Youxing Jiang1, Alice Lee, Jiayun Chen
1Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Nature
|May 31, 2002
概括
研究人员阐明了门 (K+) 通道开通的结构基础. 这项研究揭示了与K+导电性 (RCK) 域调节器的结合如何驱动MthK通道孔的机械关门.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 离子通道是关键的膜蛋白质,具有两个关键性质:选择性离子导电和调节性门.
- 门通常由连接体结合或膜电压变化启动.
- 门离子通道在细胞信号传递中起着至关重要的作用.
研究的目的:
- 介绍激活 (K+) 通道中的联结体封闭的结构基础.
- 阐明细胞内Ca2+) 结合打开MthK通道孔的机制.
主要方法:
- 从Methanobacterium thermoautotrophicum中克隆和表达MthK通道.
- 对通道的电特性进行分析.
- 确定MthK的Ca(2+) 结合的开放状态晶体结构.
主要成果:
- 晶体结构揭示了K+导电性 (RCK) 域的八个调节器,在细胞内膜表面形成一个封闭环.
- 这个封闭环直接将Ca2+) 结合起来,与打开离子通道孔所需的机械工作相结合.
- 该结构提供了通道在其开放的,Ca2+) 结合的形状的详细视图.
结论:
- 这项研究为通道中依赖的门的机制提供了第一个结构性见解.
- 该RCK域门环作为一个直接的传感器,将Ca2+) 结合能量转化为孔隙开放.
- 这项工作促进了我们对离子通道功能和调节的理解.
相关概念视频
The Role of Ion Channels in Neuronal Computation
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
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Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...


