VOLTAGE GATED ION CHANNELS--STRUCTURE AND EXPRESSION

钾通道是一组不同的离子通道， 在膜电行为的几乎所有方面。 钾 通道在真核生物的细胞中几乎是普遍存在的， 最异质的电压门控阳离子通道。 因为K+ 通道普遍参与膜兴奋性，这是可能的 动物行为和高级大脑功能的大部分方面都涉及到 钾离子通道 为了理解 K+通道的分子多样性对K+通道的行为和许多方面的影响 我们需要了解这种多样性的全部范围。 的 该建议的第一个目的是确定编码 电压依赖性钾离子通道。 相对较小的 果蝇基因组提供了一个机会，以确定一套完整的 钾离子通道在一个动物身上。 我们假设电压- 门控离子通道进化出接近最佳的结构之前， 脊椎动物和无脊椎动物物种的分离。 因此，所有的高级形式 生命的各个部分可能都有相同的基本“一套”可兴奋的通道。 到 为了验证这一点，我们建议从小鼠中克隆和表达任何新的K+通道， 果蝇中首次分离出的基因。 其他目标是：1。揭示 生物物理特性的每种类型的克隆通道，通过使用非洲爪蟾 卵母细胞表达系统; 2.以确定克隆的K+通道是否 亚基定义单独的K+通道亚家族，或者它们是否混合形成 具有来自其他基因的亚基的异源多聚体通道; 3.以确定 克隆的K+通道的体内特性，以及它们的细胞和 亚细胞分布 钾元素多样性的基础 通道基因是其功能的异质性;决定了 不同钾的功能特性和细胞分布 通道可以揭示其功能的见解。 使用方法以 对这些问题研究将涉及遗传学、北方分析、PCR 和免疫细胞化学

Potassium channels are a diverse group of ion channels which are involved in virtually all aspects of membrane electrical behavior. Potassium channels are virtually ubiquitous among the cells of eukaryotes and the most heterogeneous of the voltage-gated cation channels. Because K+ channels are universally involved in membrane excitability, it is likely that most aspects of behavior and higher brain function in animals involves potassium channels in some way. In order to understand the significance of the great molecular diversity of K+ channels to behavior and many aspects of cell biology, we need to know the full extent of this diversity. The first aim of this proposal is to identify the full "set" of genes encoding voltage-dependent potassium channels in Drosophila. The relatively tiny Drosophila genome presents an opportunity to define the complete set of potassium channels in a single animal. It is our hypothesis that voltage- gated ion channels evolved nearly optimal structures prior to the separation of vertebrate and invertebrate species. Thus, all higher forms of life may share the same essential "set" of excitable channels. To verify this we propose to clone and express from mouse, any new K+ channel genes first isolated in Drosophila. Additional aims are: 1. to reveal the biophysical properties of each type of cloned channel by using the Xenopus oocyte expression system; 2. to determine whether cloned K+ channel subunits define separate K+ channel subfamilies or whether they mix to form heteromultimeric channels with subunits from other genes; 3. to determine the in vivo properties of cloned K+ channels, and their cellular and subcellular distributions. Underlying the multiplicity of potassium channel genes is their heterogeneity of function; determining both the functional properties and cellular distribution of the different potassium channels may reveal insights into their function. The techniques to investigate these questions will involve genetics, Northern analysis, PCR and immunocytochemistry.