MOLECULAR BIOLOGY OF VISUAL RECEPTOR OUTER SEGMENTS

我们建议把视觉信号传导当作“试管中的神经信号”来研究 通过利用青蛙外节的纯化悬浮液， 其线粒体丰富的内节（OS-IS）。 我们发展这样一个 制备使我们能够同时测定和比较离子通量， 伴随着兴奋和适应的生化变化， 确定的准备，一种在现代社会尚不可能的实验， 其他神经膜制剂。 我们计划：1. 表征 光适应过程，从大视紫红质漂白中恢复， 黑暗和量子凸点膜噪声，确定它们是否 与同时发生的光诱导浓度变化相关，或 核苷酸或其他小分子的结合状态，或与共价键的结合状态。 蛋白质修饰如磷酸化。 2. 开始一个新的serarch 通过系统地测量光诱导的细胞内信使， 小有机分子的浓度或结合的变化， proteins. 3. 开发一种体外测定光敏 电导，可用于定义的必要组成部分， 转导机制，并筛选推定的电导调节剂。 这项工作中使用的实验方法和机制 被阐明是相关的理解事件之间的干预 在许多其它蜂窝系统中的输入和输出。 这种理解是 特别是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，以适当的 因此，

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.