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 这是脊椎动物感光细胞更新的基础。 续订 椎骨视网膜中的光感受器由许多不同的 在时间和空间上精心策划的细胞过程 实现感光外层的顺序更换 分段光盘。 我们最近证明，在低等脊椎动物中， 视杆细胞视蛋白 mRNA 随每日节律波动，并受到调节 通过光和昼夜节律振荡器。 在此我们建议 通过研究视杆细胞视蛋白的作用来建立在这些结果的基础上 基因表达引起这些波动。 我们将使用核 连续实验以确定基因转录是否单独 可以解释这些波动或者视蛋白 mRNA 的修饰 转录本的寿命也是必需的。 我们也想分析一下 视锥细胞视蛋白 mRNA 的产生和调节，我们将 从鱼视网膜中克隆视锥细胞视蛋白 cDNA 并分析日常 特定视锥细胞视蛋白 mRNA 水平的波动。 我们将分析 视杆细胞特有的其他蛋白质的 mRNA 产生节律 光感受器、转导蛋白和光感受器间视网膜结合 蛋白质，更清楚地了解更新过程是如何的 受监管。 我们还将检查视网膜的作用（如果有的话） 神经调节剂多巴胺引起这些波动。 我们打算 以确定光引起增加的途径 昼间照明黑暗阶段的视蛋白 mRNA 水平。 特别是要了解该规定是否取决于 直接作用于光转导并且如果它是局部控制的 或全球。 总而言之，所提出的实验应该使我们能够 了解光感受器更新是如何在细胞和 分子水平。