電圧制御のカリウムチャネルとその親類である
1Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, Massachusetts 02115, USA. gary_yellen@hms.harvard.edu
Nature
|September 6, 2002
まとめ
電圧誘導カリウムチャネルは,細胞膜を横断するイオン流れを素早く制御する重要な膜タンパク質です. その構造と機能はますます理解されているが,その機能の重要な側面については,さらなる調査が必要である.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
背景:
- ボルテージゲートカリウムチャネルは,細胞信号伝達に関与する重要な膜タンパク質です.
- これらのチャネルは,急速なゲーティング運動と高いイオン選択性を示す.
- 構造と機能の関係を理解することは,細胞の電気活動を解読する鍵です.
研究 の 目的:
- ボルトゲート式カリウムチャネルの建築モジュールと機能コンポーネントを解明する.
- これらのシグナル伝達分子の動作における未知のリンクを特定し,調査する.
主な方法:
- チャネルアーキテクチャを解明するための構造生物学技術 (例えば,冷凍-EM,X線結晶学)
- イオン輸送とゲーティング運動を研究するための電気生理学的記録.
- タンパク質の相互作用と機能領域を分析するための生化学的測定法.
主要な成果:
- イオン浸透と電圧検出の構造的基礎を明らかにするうえで,著しい進展がみられた.
- カリウムチャネルの急速なゲーティングメカニズムと高い選択性は部分的に説明されています.
- 特定の分子成分とそのチャネル機能における役割は,より明確になっています.
結論:
- 電圧ゲート式カリウムチャネルの基本的な構造と重要な機能要素は,広く理解されています.
- 経路の操作と調節を統制する複雑な分子機構を完全に解明するには,さらなる研究が必要である.
関連する概念動画
01:19Ion Channels
The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange.
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
01:19The 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.
01:26Voltage-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...
01:24Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
01:26Voltage-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...