在一个谷氨酸转运器同类体中的运输动态
Nurunisa Akyuz1, Roger B Altman, Scott C Blanchard
1Department of Physiology and Biophysics, Weill Cornell Medical College, 1300 York Avenue, New York, New York 10064, USA.
Nature
|June 25, 2013
概括
谷氨酸载体通过大域转移移移动. 一个关键步骤涉及运输领域脱离他们的脚手架,先前的跨膜运动,这可能控制运输速度.
科学领域:
- 生物化学和分子生物学
- 神经科学是一个神经科学.
- 结构生物学 结构生物学
背景情况:
- 谷氨酸转运体是关键的不可分割的膜蛋白质,负责神经递质的吸收.
- 它们的功能依赖于面向外的和面向内的状态之间的形状变化.
- 之前的模型提出了在三元架内离散的运输域的跨膜运动.
研究的目的:
- 在谷氨酸转运体中直接可视化大规模的运输域运动.
- 阐明神经递质运输过程中形状转换的机制.
主要方法:
- 使用单分子光共振能量转移 (smFRET) 成像.
- 研究了一种谷氨酸转运体的细菌同类物,以观察域动态.
主要成果:
- 直接观察到运输领域的大规模移动.
- 运输域表现出静止周期与快速过渡交替,类似于离子通道爆裂.
- 确定了基板载荷运输域在跨膜运动之前从三重体支架缓慢自发地脱离.
结论:
- 谷氨酸转运体中的动态模式是由运输域与支架的分离启动的.
- 这种脱落的步骤比随后的跨膜运动要慢得多.
- 域分离机制可能是谷氨酸转运器循环中的速度限制步骤.
相关概念视频
Facilitated Diffusion
The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane.
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
The Significance of Membrane Transport
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Active 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...
Membrane Proteins
Plasma membranes have integral transmembrane proteins involved in facilitated transport. These proteins are collectively referred to as transport proteins, and they function as either channels for the material or as carriers themselves. Channel proteins have hydrophilic domains exposed to the intracellular and extracellular fluids and a hydrophilic channel through their core that provides a hydrated opening for solutes to pass through the membrane layers. Passage through the channel allows...


