Structural Dynamics of Retinal Binding and Release

视网膜结合和释放的结构动力学

• 批准号: 8197249
• 负责人: David L Farrens
• 金额: $ 38.2万
• 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/8197249
• 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 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，他们是大多数药物的目标。我们的研究主要集中在 GPCR视紫红质及其附属蛋白。虽然参与视觉系统的关键蛋白质的晶体结构 信号转导的已知，这些蛋白质在其激活过程中经历的大多数关键结构变化 和衰减在很大程度上仍然是推测的问题。 特别是，我们缺乏甚至是最基本的信息，动态事件参与衰减视紫红质 信号传导，即，视网膜从视蛋白结合口袋中释放的机制，以及如何 视网膜的结合和释放影响抑制蛋白的结合和释放。了解这些过程是 视觉研究的基本重要性-视网膜连接的稳定性在不同的 视蛋白，并且是某些视觉疾病状态中的一个因素。此外，虽然我们知道很多关于 关于arrestin与视紫红质结合的机制和动力学，关于是什么使arrestin在结合后释放知之甚少。 结合，以及这种释放如何与视网膜发色团的状态相关。 在本提案的目的I中，我们将确定视紫红质如何控制其视网膜席夫碱的水解 联动在目标II中，我们将研究视网膜吸收和释放如何发生在视紫红质，使用最近的 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方法来跟踪一个 我们在上一个资助期内发现-arrestin可以与MIII视紫红质结合，从而捕获和 防止视网膜脱离了解arrestin如何调节视网膜释放对于 因此，抑制蛋白可用于限制在明亮的光条件下游离视网膜的释放，从而有助于限制 氧化视网膜加合物的形成，可导致老年性黄斑萎缩等疾病， 退行性变（AMD）。同样，了解是什么使arrestin在结合视紫红质后“放手”，也是 已经提出关键稳定的视紫红质-抑制蛋白复合物是细胞凋亡的贡献因子， 常染色体显性视网膜色素变性（ADRP）。