The Light-Dependent Cation Channel of Fly Photoreceptors

苍蝇感光器的光依赖性阳离子通道

• 批准号: 8819238
• 负责人: Robert Stephenson
• 金额: $ 29.15万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-15 至 1993-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8819238&HistoricalAwards=false
• 关键词: Light; Dependent; Cation; Channel; Fly

A photoreceptor cell responds to light in a series of steps. In the vertebrate eye, cyclic GMP is a compound in the photoreceptors that increases in internal concentration when the cell is illuminated. The increased concentration of cGMP then triggers opening of channels in the cell membrane that allow ions to cross it. Since the ions carry electrical charge, their movement produces the electrical event called the receptor potential. Very little is known about the light-dependent cation channel in photoreceptors of invertebrates, although invertebrates offer the promise of understanding the genetic basis for the development and regulation of this important feature. The fruit fly, Drosophila, is well-known for its use in genetic studies, and a wide variety of mutant strains are available. This project will study light-dependent cation channel in flies, using a newly developed preparation in vitro that allows access to cell membranes for the electrophysiological technique of patch-clamp recording. The properties of channel opening and closing will be established and compared with those for vertebrate photoreceptors. Biochemical compounds will identified that control the opening of the channel to compare to the cGMP role in the vertebrate photoreceptors. Visual mutants of Drosophila will be screened to identify possible genes that determine the structure or function of the genes controlling this important membrane component. This work will lead directly to the promise of genetic manipulation allowing structural analysis of these channels; such analysis of proteins important in sensory transduction will have substantial impact on all sensory science.

感光细胞通过一系列步骤对光做出反应。 在脊椎动物的眼睛中，环状 GMP 是光感受器中的一种化合物，当细胞受到照射时，其内部浓度会增加。 cGMP 浓度的增加会触发细胞膜上通道的打开，允许离子穿过细胞膜。 由于离子带有电荷，它们的运动会产生称为受体电位的电事件。 尽管无脊椎动物为了解这一重要特征的发育和调节的遗传基础提供了希望，但人们对无脊椎动物光感受器中的光依赖性阳离子通道知之甚少。 果蝇因其在遗传学研究中的应用而闻名，并且有多种突变株可供使用。 该项目将使用一种新开发的体外制剂来研究果蝇中的光依赖性阳离子通道，该制剂允许进入细胞膜以进行膜片钳记录的电生理技术。 将建立通道打开和关闭的特性，并将其与脊椎动物感光器的特性进行比较。 将鉴定控制通道开放的生化化合物，以与脊椎动物光感受器中的 cGMP 作用进行比较。 将筛选果蝇的视觉突变体，以确定可能的基因，这些基因决定控制这一重要膜成分的基因的结构或功能。 这项工作将直接带来基因操纵的前景，允许对这些通道进行结构分析；对感觉转导中重要的蛋白质的这种分析将对所有感觉科学产生重大影响。