GENETIC ANALYSIS OF RETINAL DEGENERATION

视网膜变性的遗传分析

• 批准号: 2710945
• 负责人: JOSEPH E O'TOUSA
• 金额: $ 20.82万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2710945
• 关键词: Drosophilidae; enzyme activity; enzyme substrate; gene expression; gene mutation; molecular pathology; phosphoprotein phosphatase; protein transport; retina degeneration; rhodopsin; visual photoreceptor

Specific genetic defects are responsible for a large percentage of the retinal diseases that afflict human populations. The long range goal of this research program is to characterize analogous genetically inherited retinal degeneration syndromes in the invertebrate, Drosophila, to better understand the molecular basis of degenerative retinal diseases. During previous grant periods, we determined the molecular basis of four inherited retinal degeneration syndromes in Drosophila. This proposal is focused on the cellular mechanisms by which mutations in one of these genes, rhodopsin, causes retinal disease. Rhodopsin mutations are known to cause retinal degeneration in humans, other vertebrates, and in Drosophila. In most known cases, including the Drosophila mutants we will study, the mutant rhodopsin acts in a dominant fashion to trigger degeneration. Also, the Drosophila mutants share the property with the majority of human mutant genes that they appear to disrupt the posttranslational maturation pathway. The experiments proposed here will investigate the cellular mechanisms and additional gene products involved in rhodopsin maturation and recycling. The project is organized into four specific aims: (1) To examine the dominant nature of certain Drosophila rhodopsin mutants. We will use histological markers to examine the fate of the mutant protein in photoreceptors, determine the effect of the mutant rhodopsin on other membrane proteins, and develop a genetic screen for additional genes required for rhodopsin maturation (2) To identify additional molecular components involved in rhodopsin maturation. Gene products required for membrane protein maturation through the endoplasmic reticulum/Golgi complex and for post-Golgi transport of rhodopsin will be characterized. We will analyze mechanisms involved in rhodopsin transport to the photosensitive membranes and retinal degeneration B protein transport to the specialized endoplasmic reticulum membranes of the photoreceptor. (3) To analyze the enzymatic regulation and substrate specificity of the retinal degeneration C (rdgC) gene. Rhodopsin is thought to be a substrate of the rdgC phosphatase. We will characterize the enzymatic activity of the rdgC protein and analyze mutants of rdgC exhibiting altered regulation. (4) To characterize two gene products required rhodopsin maturation already identified by mutation. These genes are required to generate high levels of rhodopsin, probably by promoting efficient utilization of vitamin A. We will determine if these ones encode proteins that act in photoreceptors, and if so, determine the molecular nature of the encoded gene.

很大一部分原因是特定的遗传缺陷 困扰人类的视网膜疾病。长期目标是 该研究计划旨在表征类似的基因遗传 无脊椎动物、果蝇的视网膜变性综合征 更好地了解退行性视网膜疾病的分子基础。 在之前的资助期间，我们确定了四个的分子基础 果蝇遗传性视网膜变性综合征。这个提议 专注于其中一种突变的细胞机制 视紫红质基因会导致视网膜疾病。视紫红质突变是已知的 导致人类、其他脊椎动物和 果蝇。在大多数已知的情况下，包括果蝇突变体，我们 将研究，突变体视紫红质以主导方式起作用以触发 退化。此外，果蝇突变体与 大多数人类突变基因似乎破坏了 翻译后成熟途径。这里提出的实验将 研究细胞机制和其他基因产物 参与视紫红质的成熟和回收。该项目已组织 分为四个具体目标： (1) 检查某些果蝇视紫红质的显性性质 突变体。我们将使用组织学标记来检查细胞的命运 光感受器中的突变蛋白，确定突变体的效果 视紫红质对其他膜蛋白的影响，并开发遗传筛选 视紫红质成熟所需的其他基因 (2) 鉴定视紫红质涉及的其他分子成分 成熟。膜蛋白成熟所需的基因产物 通过内质网/高尔基复合体和后高尔基体 将表征视紫红质的运输。我们将分析机制 参与视紫红质向光敏膜的转运 视网膜变性 B 蛋白转运至专门的内质 光感受器的网状膜。 (3) 分析酶促调控和底物特异性 视网膜变性 C (rdgC) 基因。视紫红质被认为是 rdgC 磷酸酶的底物。我们将表征酶 rdgC 蛋白的活性并分析 rdgC 的突变体 改变了监管。 (4) 表征视紫红质成熟所需的两个基因产物 已经通过突变鉴定。这些基因需要产生 高水平的视紫红质，可能是通过促进有效利用 维生素 A。我们将确定这些是否编码具有作用的蛋白质 在光感受器中，如果是的话，确定该光感受器的分子性质 编码基因。