MOLECULAR REGULATION OF POTASSIUM CHANNELS

描述：(改编自申请者摘要)长期 这项建议的目的是了解分子机制。 调节哺乳动物A-型钾离子通道的功能。这些K+ 通道对膜的响应迅速激活和失活 去极化，它们的主要功能之一是控制 重复放电发作中的神经元棘波间期。因此， A型K+通道直接影响神经元信号编码 是学习、记忆等复杂心理过程的基础 认知功能。两个不同的克隆A型K+通道将是 研究：mKv4.1编码的小鼠脑通道和人脑 由hKv3.4编码的频道。它们在膜电位下被激活 神经元放电阈值为负或正， 分别是。调节这些K+功能的机制 还没有探索过渠道。一种重组DNA的组合 方法学(例如，异源表达和体外诱变) 电生理学(电压钳和膜片钳记录)将 用于解决三个方面：第一，生物物理特性 在由mKv4.1编码的A型K+通道中，在宏观和 单通道电平。这些信息将作为以下内容的基础 了解经络功能的调节。第二，分子 黄曲霉毒素对小鼠和人A-型钾离子通道的调节机制 蛋白激酶C(PKC)。这里要解决的具体问题包括：i) 激活PKC如何控制特定K+通道的门控；ii) 所涉及的磷酸化位点的图谱(S)；以及iii) PKC作为不同A型K+通道的调节因子在心肌梗死中的意义 神经系统。第三，可能规范门控的机制 A型K+通道(mKv4.1)在它们的自然环境中。 具体探索：i)单个K+通道是如何通过 假定的本地因素；以及ii)可能揭示 涉及结构通道域。研究分子 调节A型K+通道功能的机制可能 加深对神经系统受损的脑功能的了解 和精神障碍。

DESCRIPTION: (Adapted from applicant's abstract) The long-term objective of this proposal is to understand the molecular mechanisms that regulate the function of mammalian A-type K+ channels. These K+ channels activate and inactivate rapidly in response to membrane depolarization, and one of their main functions is to control the neuronal interspike interval in episodes of repetitive firing. Thus, A-type K+ channels directly influence neuronal signal coding that underlies such complex mental processes as learning, memory and other cognitive functions. Two distinct cloned A-type K+ channels will be investigated: mouse brain channels encoded by mKv4.1 and human brain channels encoded by hKv3.4. They activate at membrane potentials negative or positive to the neuronal firing threshold, respectively.The mechanisms that regulate the function of these K+ channels have not been explored. A combination of recombinant DNA methodology (e.g., heterologous expression and mutagenesis in vitro) and electrophysiology (voltage-clamp and patch-clamp recording) will be used to address three aspects: First, the biophysical properties of A-type K+ channels encoded by mKv4.1, at the macroscopic and single channel levels. This information will serve as the basis for understanding regulation of channel function. Second, the molecular mechanisms of regulation of mouse and human A-type K+ channels by protein kinase C (PKC). Specific questions to address here are: i) how activation of PKC controls gating of specific K+ channels; ii) mapping of the phosphorylation site(s) involved; and iii) the significance of PKC as regulator of distinct A-type K+ channels in the nervous system. Third, the mechanisms that may regulate gating of A-type K+ channels (mKv4.1) in their native environment. Specifically exploring: i) how single K+ channels are fine tuned by putative native factors; and ii) strategies that may reveal the structural channel domains involved. Studying the molecular mechanisms that regulate the function of A-type K+ channels may enhance our understanding of brain functions impaired in neurological and psychiatric disorders.