張力依存のK+チャネルのサイトプラズミックβサブユニット-T1アセンブリの構造
1Howard Hughes Medical Institute and Laboratory of Molecular Neurobiology and Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Science (New York, N.Y.)
|July 7, 2000
まとめ
電圧依存性カリウムチャネルの細胞質組成は,X線結晶学を用いて決定した. これは,チャネル機能と不活性化ペプチドへのアクセスを決定的に重要なT1(4) beta4複合体を明らかにしました.
科学分野:
- 構造生物学 構造生物学とは
- 分子神経科学は分子神経科学である.
- バイオフィジックス 生物物理学
背景:
- 電圧に依存するカリウムチャネルは,神経細胞の興奮性にとって極めて重要です.
- 細胞質のT1ドメインとβサブユニットは,チャネル機能を調節する.
- 細胞プラズマの組み立てを理解することは,K+チャネル機構の鍵です.
研究 の 目的:
- 電圧依存のK+チャネルのサイトプラズマ集合体の高解像度構造を決定する.
- チャネルゲッティングと無活性化ペプチド相互作用の構造的基礎を解明する.
主な方法:
- 2.1アングストームの解像度のX線結晶学.
- 複雑な指向と機能を決定するための電気生理学的測定法.
主要な成果:
- T1(4) beta4複合体の構造は解き,四重対称性を示した.
- 複合体は,T1ドメインが毛穴に面し,ベータサブユニットは細胞質に面している.
- 横の開口は,毛穴と細胞質をつなぎ,不活性化ペプチドのアクセスを可能にします.
結論:
- 解けた構造は,細胞質K+チャネルアセンブリの詳細な分子モデルを提供します.
- この構造は,不活性化ペプチドが細胞質の標的にどのようにアクセスするかを説明します.
- この発見は,カリウムチャネル機能の調節に関する洞察を提供します.
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.
01:26Voltage-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...
01:12Mechanically-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...
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...
01:12Mechanically-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...