ポーリー領域が欠けている電圧ゲート型陽子選択チャネル
I Scott Ramsey1, Magdalene M Moran, Jayhong A Chong
1Howard Hughes Medical Institute, Department of Cardiology, Children's Hospital, Harvard Medical School, Enders 1309, 320 Longwood Avenue, Boston, Massachusetts 02115, USA.
Nature
|March 24, 2006
まとめ
研究者らは,毛穴領域を持たないが,免疫細胞機能に不可欠な新種の哺乳類の電圧ゲート型陽子チャンネル (H(v) 1を特定した. この発見は,陽子輸送と先天性免疫の理解を前進させる.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生理学 細胞生理学
- 免疫学 免疫学とは
背景:
- 細胞機能に不可欠な電圧ゲートイオンチャネルには,ゲートを調節する電圧感知ドメイン (VSD) がある.
- VSDは通常,イオンチャネル孔と結びついているが,Ci-VSPのようなVSDタンパク質は,イオンチャネルとは独立して機能する.
- 哺乳類の電圧ゲート型陽子チャネルの存在と機能は,ほとんど特徴づけられていなかった.
研究 の 目的:
- 新しい哺乳類の電圧ゲートプロトンチャネルを特定し,特徴づけること.
- この新たに特定されたチャネルの機能的性質と規制メカニズムの解明.
- 免疫反応におけるこのチャネルの役割を決定する.
主な方法:
- 哺乳類のVSDタンパク質の発現と電気生理学的分析,H(v) 1.1.
- サイト・ディレクテッド・ミュータゲネシスで,ゲーティングと阻害に関与する主要な残留物を特定する.
- 免疫組織におけるH(v) 1発現の調査と,ファゴサイト性白血球におけるその役割.
主要な成果:
- 哺乳類のVSDタンパク質であるH(v) 1は,識別可能な毛穴領域とは独立した,機能的な電圧ゲートプロトンチャネルとして識別されました.
- H(v) 1電流は脱極化によって活性化され,陽子選択性があり,特定のヒスティジン残留物を通して Zn2+ によって抑制されます.
- H(v) 1は免疫細胞で発現し,ファゴシートの酸化爆発に不可欠な陽子伝導 (G(vH+)) を媒介する.
結論:
- H(v) 1は,最初に確認された哺乳類の電圧ゲートプロトンチャネルであり,VSDタンパク質の既知の機能を拡張しています.
- この研究では,H(v) 1が,特に微生物の殺戮において,先天的な免疫システムの重要な構成要素であることを確認しました.
- H(v) 1は,さまざまな生理学的役割を持つ哺乳類のVSDタンパク質の新しいファミリーの創設メンバーです.
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関連する概念動画
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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.
01:26Voltage-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.
01:21Electrochemical Gradient and Channel Proteins: An Overview
An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to 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...