Structural Dynamics of Retinal Binding and Release

视网膜结合和释放的结构动力学

• 批准号: 8403607
• 负责人: David L Farrens
• 金额: $ 36.29万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8403607
• 关键词: Address; Affect; Affinity; Apoptosis; Arrestins; Attenuated; Binding; Biological Assay; Complex; Data; Disease; Event; Family; Funding; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; GTP-Binding Proteins; Goals; Health; Human; Human Genome; Hydrolysis; Kinetics; Leber' s disease; Life; Light; Methods; Modeling; Molecular; Monitor; Mutagenesis; Mutation; Night Blindness; Nonexudative age-related macular degeneration; Opsin; Pharmaceutical Preparations; Pharmacologic Substance; Play; Process; Proteins; Research; Resolution; Retinal; Retinal Cone; Retinal Degeneration; Retinal Diseases; Retinitis Pigmentosa; Rhodopsin; Role; Scheme; Schiff Bases; Signal Transduction; Site; Structure; System; Testing; Time; Vertebrate Photoreceptors; Vision; Vision research; Visual; Visual Signal Transduction Pathway; Work; adduct; attenuation; base; chromophore; design; follow-up; insight; novel; preference; prevent; protein structure; receptor; receptor coupling; research study; theories; uptake

PROJECT SUMMARY The long-term goal of our research is to understand the molecular mechanisms through which G-protein coupled receptors (GPCRs) are activated and attenuated. These receptors represent the largest family in the human genome, and they are the target of most pharmaceutical drugs. We focus our studies primarily on the GPCR rhodopsin and its affiliate proteins. Although crystal structures of key proteins involved in visual signaling are now known, most of the critical structural changes these proteins undergo during their activation and attenuation remain largely a matter of speculation. In particular, we lack even rudimentary information about the dynamic events involved in attenuating rhodopsin signaling, namely, the mechanisms through which retinal is released from the opsin-binding pocket, and how retinal binding and release affects arrestin binding and release. Understanding these processes is of fundamental importance for vision research - the stability of the retinal linkage varies widely among different opsins and is a factor in some visual disease states. Furthermore, although much is known about the mechanism and kinetics of arrestin binding to rhodopsin, little is known about what makes arrestin release after binding, and how this release is related to the status of the retinal chromophore. In Aim I of this proposal we will determine how rhodopsin controls the hydrolysis of its retinal Schiff base linkage. In Aim II we will examine how retinal uptake and release occurs in rhodopsin, using the recent structure of opsin to guide our studies. Finally, in Aim III, we will use our novel methods to follow up on a discovery we made during the last funding period - that arrestin can bind to MIII rhodopsin, thus trapping and preventing retinal release. Understanding how arrestin regulates retinal release is fundamentally important to health, as arrestin may serve to limit the release of free retinal under bright light conditions, and thus help limit the formation of oxidative retinal adducts that can contribute to diseases like atrophic age-related macular degeneration (AMD). Similarly, understanding what makes arrestin "let go" after binding rhodopsin is also crucial - stable rhodopsin-arrestin complexes have been suggested to be a contributing factor in apoptosis and autosomal dominant retinitis pigmentosa (ADRP).

项目概要 我们研究的长期目标是了解 G 蛋白的分子机制 偶联受体（GPCR）被激活和减弱。这些受体代表了最大的家族 人类基因组，它们是大多数药物的目标。我们的研究主要集中在 GPCR 视紫质及其附属蛋白。尽管参与视觉的关键蛋白质的晶体结构 现在已知信号传导，这些蛋白质在激活过程中经历的大部分关键结构变化 和衰减在很大程度上仍然是猜测的问题。 特别是，我们甚至缺乏有关减弱视紫红质的动态事件的基本信息 信号传导，即视网膜从视蛋白结合袋释放的机制，以及如何 视网膜结合和释放影响视紫红质抑制蛋白的结合和释放。了解这些过程的意义在于 对于视觉研究至关重要 - 视网膜连接的稳定性在不同的国家之间差异很大 视蛋白是某些视觉疾病状态的一个因素。此外，尽管人们对 视紫红质抑制蛋白与视紫红质结合的机制和动力学，对于抑制蛋白在结合后释放的原因知之甚少。 结合，以及这种释放如何与视网膜发色团的状态相关。 在本提案的目标 I 中，我们将确定视紫红质如何控制其视网膜希夫碱的水解 连锁。在《目标 II》中，我们将利用最新的研究成果来研究视网膜对视紫红质的摄取和释放是如何发生的。 视蛋白的结构来指导我们的研究。最后，在目标 III 中，我们将使用我们的新颖方法来跟进 我们在上一个资助期间取得的发现——视紫红质抑制蛋白可以与 MIII 视紫红质结合，从而捕获并捕获 防止视网膜释放。了解抑制蛋白如何调节视网膜释放对于 健康，因为抑制蛋白可能有助于限制亮光条件下游离视网膜的释放，从而有助于限制 氧化性视网膜加合物的形成，可能导致年龄相关性黄斑萎缩等疾病 变性（AMD）。同样，了解抑制蛋白在结合视紫红质后“释放”的原因也是 至关重要 - 稳定的视紫红质 - 抑制蛋白复合物已被认为是细胞凋亡和 常染色体显性遗传色素性视网膜炎（ADRP）。