MOLECULAR BIOLOGY OF VISUAL RECEPTOR OUTER SEGMENTS

我们建议将视觉传导作为“试管中的神经信号”来研究。 通过利用纯化的蛙外节悬浮液仍然附着在 线粒体丰富的内节(OS-IS)。我们开发了这样一个 分离允许我们同时分析和比较离子通量和 在化学上伴随着兴奋和适应的生化变化 限定的制剂，一种目前还不可能实现的实验 其他神经膜制剂。我们计划：1.描述 光适应的过程，从大视紫质漂白中恢复 黑暗和量子凹凸膜的噪音，决定了它们是否 与同时光诱导的浓度变化或 核苷酸或其他小分子的结合状态，或与共价的结合状态 蛋白质修饰，如磷酸化。2.开始搜索新的 系统研究光诱导可能的细胞内信使 小有机分子的浓度或结合的变化和 蛋白质。3.建立了一种光敏性的体外检测方法 可用于定义必要组件的电导 转导机制，以及筛选可能的电导调节因子。 这项工作中使用的实验方法和机制 被阐明与理解介于 在许多其他蜂窝系统中的输入和输出。这样的理解是 尤其与定义疾病潜在的扰动有关 视网膜的状态，并允许更合理的方法来适当地 就是这样。

We propose to study visual transduction as "a nerve signal in a test tube" by utilizing purified suspensions of frog outer segments still attached to their mitochondria rich inner segments (OS-IS). Our development of such a peparation permits us to simultaneously assay and compare ion fluxes and biochemical changes accompanying excitation and adaptation in a chemically defined preparation, experiments of a sort that are not yet possible in other nerve membrane preparations. We plan to: 1. Characterize the processes of light adaptation, recovery from large rhodopsin bleaches in the dark, and quantum bump membrane noise, determining whether they correlate with simultaneous light-induced changes in the concentration or binding state of nucleotides or other small molecules, or with covalent protein modifications such as phosphorylation. 2. Begin a serarch for new putative intracellular messengers by systematically surveying light-induced changes in the concentration or binding of small organic molecules and proteins. 3. Develop an in vitro assay for the light-sensitive conductance that can be used to define the necessary components of the transduction mechanism and also to screen putative conductance regulators. The experimental approaches being used in this work and the mechanisms being elucidated are relevant to understanding events intervening between input and output in many other cellular systems. Such understanding is especially relevant to defining the perturbations underlying diseased states of the retina, and permits a more rational approach to appropriate thereapy.