激活BK(Ca) 通道缺乏碗和RCK域的激活
Rebecca Piskorowski1, Richard W Aldrich
1Department of Molecular and Cellular Physiology, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305-5345, USA.
Nature
|December 6, 2002
概括
大导电激活 (BK(Ca)) 通道将信号与细胞刺激性联系起来. 这项研究揭示了C端区域对于BK (Ca) 通道激活并不重要,挑战了先前的假设.
科学领域:
- 分子生物学分子生物学
- 神经科学是一个神经科学.
- 生物物理学的生物物理.
背景情况:
- 大导电激活 (BK(Ca)) 通道对于神经递质释放和平滑肌肉放松等生理过程至关重要.
- 这些通道连接细胞内信号通道与细胞膜刺激性.
- BK(Ca) 通道的激活取决于膜电压和细胞内的度.
研究的目的:
- 研究细胞内C终端区域在BK(Ca) 通道的依赖激活中的作用.
- 确定C端,包括"碗"和RCK域,是否在生理条件下对于BK(Ca) 通道功能是必要的.
主要方法:
- 电生理学记录BK(Ca) 通道活动.
- 使用缺乏整个细胞内C终端域的BK(Ca) 通道变体.
主要成果:
- 在没有细胞内C终端的情况下设计的BK(Ca) 通道对有正常的敏感性.
- 这些发现表明,C端不需要激活开放BK ((Ca)) 通道.
- 在C端的"碗"和RCK域对于门并不重要.
结论:
- BK(Ca) 通道的细胞内C终端对于介导的激活是不可或缺的.
- 这挑战了长期以来的假设,即结合部位仅位于C端区域.
- 其他机制或区域可能是BK ((Ca)) 通道敏感性的原因.
相关概念视频
Voltage-gated Ion Channels
12.6K
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...
12.6K
Calmodulin-dependent Signaling
6.9K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
6.9K
Feedback Regulation of Calcium Concentration
4.1K
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
4.1K
Antihypertensive Drugs: Action of Calcium Channel Blockers
2.1K
Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,...
2.1K
The Role of Ion Channels in Neuronal Computation
4.2K
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential....
4.2K
Ligand-Gated Ion Channel Receptor: Gating Mechanism
4.6K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
4.6K


