QUANTAL EVENTS IN VISUAL TRANSDUCTION

视觉传导中的量子事件

• 批准号: 3264509
• 负责人: DAVID W CORSON
• 金额: $ 11.02万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-01 至 1994-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3264509
• 关键词: Anura; Urodela; binding proteins; calcium; chromophore; electrophysiology; fresh water environment; guanosine triphosphate; horseshoe crabs; inositol phosphates; laboratory rat; membrane permeability; photostimulus; quantum chemistry; retinoids; rhodopsin; rod cell; spectrometry; transducin; visible light; visual phototransduction

We propose to explore the physiological mechanisms which shape the discrete responses of photoreceptors to single photons of light. Now that the underlying biochemical similarities among families of signal transduction cascades including those of both vertebrate and invertebrate vision are firmly established, we propose to determine how rhodopsin, GTP-binding proteins and calcium ions control the changes in permeability of thousands of ion channels which give rise to discrete single photon responses. The goals of this proposal are: 1) to determine whether GTP analogs allow a single photoactivated rhodopsin molecule to produce more than one discrete wave in vertebrate rod photoreceptors as they do in Limulus, 2) to determine whether structural changes in rhodopsin chromophores alter the latency or shape of the responses to single photons in Limulus photoreceptors and vertebrate rods and 3) to measure the time course of calcium elevation associated with individual responses to single photons in Limulus. Preliminary work with GTP analogs in the ventral photoreceptors of Limulus have demonstrated the feasibility of this general physiological approach. The first goal is an extension of this work to vertebrate phototransduction. The second goal is also a logical extension of preliminary work in Limulus and takes advantage of a unique opportunity for collaboration that exists at the Medical University of South Carolina. The third goal is a point of departure for a new exploration of the complex role of calcium in phototransduction. A detailed understanding of the physiological mechanisms of receptor-mediated signal transduction cascades should have multiple long range applications in the analysis and treatment of eye disease.

我们建议探索形状的生理机制 光感受器对单个光子的离散响应 光。 现在，之间的基本生化相似性 信号转导级联的家族包括两个 脊椎动物和无脊椎动物的视力牢固，我们 提议确定视紫红质，GTP结合蛋白和 钙离子控制数千个渗透性的变化 产生离散单光子响应的离子通道。 该提案的目标是：1）确定GTP是否是否 类似物允许单个光活化的视紫红质分子到达 在脊椎动物杆上产生多个离散波 像在利卢卢斯一样的感光器，2）确定是否 视紫红质发色团的结构变化改变了潜伏期或 利感受器中对单光子的响应的形状 和脊椎动物杆以及3）测量钙的时间过程 与单个对单个光子的响应相关的高程 利卢斯。 腹侧光感受器中的GTP类似物的初步工作 利利卢斯已经证明了这一一般的可行性 生理方法。 第一个目标是扩展这项工作 脊椎动物光转导。 第二个目标也是合乎逻辑的 扩展利利卢斯的初步工作，并利用 医疗存在的独特合作机会 南卡罗来纳大学。 第三个目标是 出发探索钙在 光转导。 对生理的详细理解 受体介导的信号转导级联机理 在分析中应该具有多个远程应用程序，并且 眼病的治疗。