CELLULAR MECHANISMS OF VERTEBRATE PHOTORECEPTOR RENEWAL

脊椎动物光感受器更新的细胞机制

• 批准号: 3265594
• 负责人: JUAN IGAL KORENBROT
• 金额: $ 23.71万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1994-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3265594
• 关键词: binding proteins; circadian rhythms; cone cell; dopamine; fish; fresh water environment; gene expression; genetic transcription; light intensity; messenger RNA; nuclear runoff assay; photobiology; retina; retinoid binding proteins; rhodopsin; rod cell; transducin; visual photoreceptor; visual phototransduction

Our long term objective is to understand the cellular mechanisms which underly vertebrate photoreceptor renewal. Renewal of photoreceptors in the vertebrae retina consists of many diverse cellular processes which are orchestrated both in time and space to effect the sequential replacement of photoreceptive outer segment discs. We have recently demonstrated that in lower vertebrates, the level of rod opsin mRNA fluctuates with a daily rhythm, and is regulated both by light and by a circadian oscillator. Here we propose to build on these results by investigating the role of the rod opsin gene expression in causing these fluctuations. We will use nuclear run-on experiments to establish whether gene transcription alone can account for these fluctuations or if modification of opsin mRNA transcript lifetime is also required. We also intend to analyze the production and regulation of cone opsin mRNA for which we will clone cone opsin cDNA from fish retina and analyze the daily fluctuations in specific cone opsin mRNA levels. We will analyze the rhythms of mRNA production for other proteins specific to rod photoreceptors, transducin and interphotoreceptor retinal binding protein, to understand more clearly how the renewal process is regulated. We will also examine the role, if any, of the retinal neuromodulator dopamine in causing these fluctuations. We intend to ascertain the pathway by which light elicits an increase in opsin mRNA level during the dark phase of diurnal illumination. In particular, to understand whether or not this regulation depends on directly on phototransduction and if it is controlled locally or globally. Taken together, the proposed experiments should allow us to understand how photoreceptor renewal is regulated at a cellular and molecular level.

我们的长期目标是了解细胞机制 脊椎动物光感受器更新。 更新 椎骨视网膜中的光感受器由多种多样的 在时间和空间上精心策划的蜂窝过程 实现光感受体外部的顺序替换 细分光盘。 我们最近证明，在较低的脊椎动物中 Rod opsin mRNA的每日节奏波动，并受到调节 无论是通过光还是昼夜振荡器。 在这里我们建议 通过研究Rod Opsin的作用来建立这些结果 引起这些波动的基因表达。 我们将使用核 运行实验以确定单独基因转录是否单独 可以说明这些波动或如果修改Opsin mRNA 还需要成绩单寿命。 我们还打算分析 锥锥mRNA的生产和调节，我们将 来自鱼视网膜的克隆锥蛋白cDNA并分析每日 特定的锥蛋白mRNA水平的波动。 我们将分析 针对杆的其他蛋白质的mRNA产生的节奏 感光细胞，转霉素和球形受体视网膜结合 蛋白质，更清楚地了解更新过程的方式 受监管。 我们还将检查视网膜的角色（如果有的话） 神经调节剂多巴胺导致这些波动。 我们打算 确定光引起的途径增加 在昼夜照明的黑暗阶段，Opsin mRNA水平。 特别是了解该法规是否取决于 直接在光转录上，如果是在本地控制的 或全球。 综上所述，拟议的实验应使我们能够 了解如何在细胞和 分子水平。