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).

项目摘要 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）被激活并减弱。这些受体代表了 人类基因组，它们是大多数药物的靶标。我们将研究重点放在 GPCR视紫红质及其关联蛋白。虽然与视觉相关的关键蛋白的晶体结构 现在已知信号，大多数关键结构变化这些蛋白质在激活过程中都会发生 并且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涉及的动态事件的基本信息 信号传导，即，视网膜从Opsin结合袋中释放出视网膜的机制，以及如何 视网膜结合和释放会影响逮捕蛋白的结合和释放。了解这些过程是 对视力研究的根本重要性 - 视网膜连接的稳定性在不同的不同之不同 Opsins是某些视觉疾病状态的一个因素。此外，尽管对 抑制蛋白与视紫红质结合的机制和动力学，几乎不知道是什么使释放逮捕蛋白在 结合，以及该释放与视网膜发色团的状态有关。 在该提案的目标中，我们将确定视紫红质如何控制其视网膜席夫基地的水解 连锁。在AIM II中，我们将使用最近的视网膜摄取和释放在视网膜上发生 Opsin的结构指导我们的研究。最后，在AIM III中，我们将使用我们的新方法跟进 我们在最后一个资金期间进行的发现 - 逮捕素可以与MIII若订地蛋白结合，从而捕获和 防止视网膜释放。了解逮捕素如何调节视网膜释放对 健康，因为逮捕可能会限制在明亮的光线条件下自由视网膜的释放，从而有助于限制 形成氧化性视网膜加合物，可能导致疾病等疾病与萎缩相关的黄斑 变性（AMD）。同样，理解是什么使逮捕蛋白在约束视紫红质后“放开”也是 至关重要的 - 稳定的视紫红质 - arrestin络合物被认为是凋亡和 常染色体显性视网膜炎色素（ADRP）。