フォスフォリピドと,電圧センサーのカチオンゲーティング電荷の起源
Daniel Schmidt1, Qiu-Xing Jiang, Roderick MacKinnon
1Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Nature
|December 1, 2006
まとめ
細胞膜は,電圧センサーにとって理想的な条件を作り出します. 負の電荷を持つフォスフォリピドは,電圧に依存するカリウムチャネルを安定させ,細胞信号伝達の適応を強調する.
科学分野:
- バイオケミストリー バイオケミストリー
- 細胞生物学 細胞生物学
- バイオフィジックス 生物物理学
背景:
- 細胞膜は,物理的,化学的プロセスを通してコミュニケーションを容易にする.
- 電圧センサーを含む膜タンパク質は,細胞機能にとって極めて重要です.
- 電圧センサーは膜の電圧を検知し,イオン流と酵素活性を調節します.
研究 の 目的:
- 細胞膜環境が電圧センサーの機能をどのようにサポートするかを調査する.
- フォスフォリピドが電圧依存イオンチャネルの動作における役割を決定する.
主な方法:
- 電圧依存および非電圧依存のK+チャネルの実験分析.
- チャンネル機能を評価するための様々な実験条件.
- タンパク質ドメインと膜成分との相互作用を分析する.
主要な成果:
- 電圧に依存するK+チャネルの機能は,フォスフォリピドの負の電荷を持つフォスフォディエステル群によって著しく影響を受けます.
- 非電圧依存のK+チャネルは,この依存性を示さない.
- 安定作用は,電圧センサーの陽性電荷のアルギニン残留物と,陰性電荷の脂質フォスフォディエスターの間に発生する.
結論:
- フォスフォリピド膜は,電圧感知機械のエネルギー安定と動作に適した環境を提供します.
- 電圧センサーにアルギニン残留物の存在は,細胞膜のフォスフォリピド組成に適応している可能性が高い.
- この相互作用は,電圧に依存する細胞プロセスの適切な機能に不可欠です.
関連する概念動画
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.
01:19Ligand-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...
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.
01:19Ligand-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...
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...