COVALENT ACTIVATION OF SINGLE RETINAL ROD ION

单视网膜杆离子的共价激活

• 批准号: 2160851
• 负责人: MARIALUISA RUIZ
• 金额: $ 2.37万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-03-18 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2160851
• 关键词: COVALENT; ACTIVATION; SINGLE; RETINAL; ROD

This proposal describes an unique approach for a detailed analysis of the activation process of the retinal rod cyclic GMP-gated channel. The light response in retinal photoreceptors causes intracellular levels of cGMP to drop, thereby closing cGMP-gated channels and generating an electrical signal to the brain. Structural and kinetic studies indicate that two different subunits assemble into heteromeric channels, but it is not known how each binding event contributes to activation. A photoaffinity cGMP analog will be used to freeze the channel in different states of activation. Single channel analysis will allow the following questions to be addressed: 1. What are the details of channel activation? This includes identifying the states the channel goes through during activation, and how cooperativity is achieved. 2. How does the P subunit effect activation and at which steps? Results from homomeric channels (formed from subunits) and heteromeric channels will be compared with native channels which express a 240 kD 13 subunit. 3. Do different patterns of subunit occupancy by cGMP lead to different channel behaviors? A detailed analysis of the steps leading to activation of this channel will give insight into how it participates in phototransduction. Cyclic nucleotide-gated channel isoforms have been identified in rods, cones, olfactory neuroepithelium, heart, sperm, and kidney. Knowledge of the contribution of different elements to activation might help to understand the roles these isoforms play in different tissues, and facilitate tissue specific targeting in therapeutic applications.

该建议描述了一种独特的方法，用于详细分析 视网膜棒环GMP门控通道的激活过程。光 视网膜感受器的反应会导致细胞内CGMP 掉落，从而关闭CGMP门控通道并产生电气 向大脑发出信号。结构和动力学研究表明两个 不同的亚基组装成异类通道，但不是 知道每个结合事件如何有助于激活。一个照片亲和力 CGMP模拟将用于冻结不同状态的通道 激活。单渠道分析将允许以下问题 要解决： 1。频道激活的细节是什么？这包括识别 渠道在激活期间通过的状态以及如何 达成了合作。 2。p亚基如何影响激活以及在哪个步骤下？结果 来自同源通道（由亚基形成）和异类通道 将与表达240 kD 13亚基的天然通道进行比较。 3。执行CGMP的不同子单位占用模式导致不同 渠道行为？ 对导致激活此通道的步骤的详细分析 将深入了解其如何参与光转导。 循环 核苷酸门控通道同工型已在杆，锥，， 嗅觉神经上皮，心脏，精子和肾脏。 了解 不同元素对激活的贡献可能有助于理解 这些同工型在不同组织中起着作用，并促进组织 在治疗应用中的特定靶向。