VOLTAGE GATED ION CHANNELS--STRUCTURE AND EXPRESSION

钾通道是一组不同的离子通道，涉及 几乎在膜的所有方面都有电学行为。钾 通道在真核生物的细胞中几乎无处不在， 电压门控阳离子通道中最不均匀的。因为K+ 通道广泛参与膜兴奋性，很可能 动物的行为和高级大脑功能的大部分方面涉及 某种程度上的钾通道。为了更好地理解 钾离子通道对行为和多方面的巨大分子多样性 对于细胞生物学，我们需要知道这种多样性的全面程度。这个 这项提议的第一个目标是确定编码基因的全部“集合” 果蝇的电压依赖性钾通道。相对较小的 果蝇基因组提供了一个机会来定义完整的 单个动物体内的钾通道。我们的假设是电压- 门控离子通道在进化出近乎最佳的结构之前 脊椎动物和无脊椎动物物种的分离。因此，所有更高级的形式 生活中的每一个人都可能共享同样的“一套”可兴奋的通道。至 验证这一点，我们建议克隆并表达任何新的K+通道 在果蝇中首次分离到基因。其他目标是：1.揭示 利用非洲爪哇克隆的每种渠道的生物物理特性 卵母细胞表达系统；2.确定是否克隆了K+通道 亚基定义单独的K+通道亚家族，或者它们是否混合形成 具有其他基因亚基的异源多聚体通道；3.确定 克隆的K+通道的体内特性及其细胞和 亚细胞分布。在钾的多样性背后 通道基因是它们功能的异质性；决定了 不同钾的功能特性和细胞分布 渠道可能揭示其功能的洞察力。实现以下目标的技术 对这些问题的调查将涉及遗传学、Northern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.