GATING AND IONIC CURRENTS OF CLONED POTASSIUM CHANNELS

克隆钾通道的门控和离子电流

• 批准号: 2171442
• 负责人: RAYMOND S HURST
• 金额: $ 2.37万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-01-25 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2171442
• 关键词: GATING; IONIC; CURRENTS; CLONED; POTASSIUM

Potassium channels play an integral role in regulating the activity of excitability of cells such as nerve and muscle. When potassium channels are open, potassium flows down its concentration gradient from inside to outside the cell. This draws the membrane away from the firing threshold and thereby decreases cell excitability. The opening and closing of voltage dependent potassium channels is regulated by the membrane potential channels open as the membrane is depolarized. The voltage dependence of channel opening arises from conformational changes in which there is a net movement of charge across the electric field of the membrane. This charge movement can be measured as a transient "gating currents" in voltage clamp experiments. The long term goal of this proposal is to define the structural domains that couple this charge movement to the opening and closing of voltage dependent potassium channels. This proposal focuses on two main aspects: 1) pharmacological agents that interact with the gating mechanism of voltage dependent potassium channels and 2) two potassium channel clones that couple differently charge movement and channel closing as assayed by internal tetraethylammonium. The experiments employ both the patch clamp and cut open oocyte Vaseline gap techniques to measure ionic and gating current from cloned potassium channels. These studies should provide meaningful insight to the mechanisms by which potassium channel activity is modulated by membrane potential and may reveal mechanisms for their regulation.

钾离子通道在调节细胞膜的活性中起着不可或缺的作用。 神经和肌肉等细胞的兴奋性。 当钾离子通道 钾离子沿着浓度梯度从内部流向 在细胞外。这会将膜拉离放电阈值 从而降低细胞兴奋性。的打开和关闭 电压依赖性钾通道由膜调节 当膜去极化时，潜在的通道打开。 的电压 通道开放的依赖性来自构象变化， 存在电荷在电场中的净移动， 膜的这种电荷移动可以被测量为瞬态“门控 电流”的电压钳实验。长期目标是 建议是定义耦合这种电荷的结构域 电压依赖性钾离子的开放和关闭运动 渠道 该建议集中在两个主要方面：1）药理学试剂， 与电压依赖性钾通道的门控机制相互作用 通道和2）两个钾通道克隆， 电荷移动和通道关闭，通过内部 四乙基铵实验采用膜片钳和切割 开放卵母细胞凡士林间隙技术测量离子和门控电流 克隆钾离子通道这些研究将提供有意义的 了解钾通道活性的机制， 调节膜电位，并可能揭示其机制， 调控