Na+,K+-ATフェーズを通じたイオン浸透
Nicolás Reyes1, David C Gadsby
1Laboratory of Cardiac/Membrane Physiology, The Rockefeller University, New York, New York 10021, USA.
Nature
|September 29, 2006
まとめ
P型ATPアゼポンプは,細胞膜に横断してイオングラデーションを生成する. 研究者はNa+,K+-ATPaseイオン経路を調査し,前庭,電荷選択性フィルター,およびカチオン輸送に不可欠な重要な酸性残留物を明らかにしました.
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.
- 細胞生物学 細胞生物学
背景:
- P型ATPアゼポンプは,細胞のイオングラデーションを維持するために不可欠です.
- これらのポンプは,イオン輸送のための規制されたゲートを持つ極性トランスメブラン経路を使用します.
- Na+,K+-ATPaseは,ほぼすべての細胞に存在する重要なイオンポンプです.
研究 の 目的:
- Na+,K+-ATPASEを通るイオン経路を解明する.
- ポンプの経路の構造と電荷選択性の性質を調査する.
- イオン調整と選択性における特定の残留物の役割を理解する.
主な方法:
- Na+,K+-ATPaseゲートを分離するために,海洋毒素パリトキシンを利用しました.
- 細胞外探査機として小型,水性,チオール固有の反応剤を使用した.
- 予想されるカチオン経路に沿って導入されたシステイン残留物は,反応剤の反応を監視する.
主要な成果:
- 充電選択性フィルター付きの狭い通路につながる広い外側の玄関口を特定しました.
- 保存された酸性残留物がイオンを調整し,カチオン選択性にとって重要であることを示した.
- 単一の酸性残留物の電荷の逆転が,アニオン選択性への経路を変換することを示した.
結論:
- Na+,K+-ATPase経路は,アクセシブルな玄関口と電荷選択フィルターを備えています.
- 特定の酸性残留物は,カチオン結合と輸送に不可欠であり,経路の選択性を決定する.
- 構造的な類似性は,他のP型ATPases (Ca2+,H+,K+-ATPases) にも類似したカチオン交換経路を示唆する.
さらに関連する動画
07:38Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
Published on: March 30, 2015
08:34Contribution of the Na+/K+ Pump to Rhythmic Bursting, Explored with Modeling and Dynamic Clamp Analyses
Published on: May 9, 2021
関連する概念動画
01:47Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
01:27ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
01:14Active Transport
Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition.
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...