Mechanisms of photoreceptor disc maturation

感光盘成熟的机制

• 批准号: 10608095
• 负责人: Vadim Y Arshavsky
• 金额: $ 48.26万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10608095
• 关键词: 3-Dimensional; Address; Affect; Anatomy; Animals; Biology; Biotinylation; Blindness; Cadherins; Cell membrane; Cellular biology; Cilia; Cone; Cyclic GMP; Data; Defect; Disease; Dynamin; Electron Microscopy; Etiology; Extracellular Domain; Frustration; Individual; Inherited; Intervention; Knock-in Mouse; Knock-out; Knockout Mice; Lateral; Lead; Light; Link; Mammals; Membrane; Metalloproteases; Molecular; Morphogenesis; Morphology; Mus; Organelles; Pharmacological Treatment; Phenotype; Photons; Photoreceptors; Prevalence; Prevention; Process; Property; Protein Isoforms; Proteins; Retinal Degeneration; Rod; Role; Signal Transduction; Structure; Structure of retinal pigment epithelium; Surface; Testing; Time; Tomogram; Vertebrate Photoreceptors; Vesicle; Vision; Vision Disorders; Vision research; base; conditional knockout; design; experimental study; extracellular; fascinate; inherited retinal degeneration; malformation; mutant; peripherin; pharmacologic; photoreceptor degeneration; photoreceptor disc; prevent; reconstruction; response; scaffold; tomography; tool

The experiments described in this proposal address one of the most fascinating unanswered questions in vision research regarding the molecular mechanisms responsible for photoreceptor outer segment morphogenesis. The outer segment is a ciliary organelle that produces electrical signals in response to capturing light. A unique morphological feature of the outer segment is that it is filled with a stack of flattened membrane discs providing vast surfaces for photon capture and signal amplification. The functional significance of this anatomical arrangement has been recognized for a very long time, yet our understanding of how discs are built at the molecular level remains frustratingly rudimentary. This application addresses several poorly understood aspects of photoreceptor disc morphogenesis, related to the processes of disc expansion, alignment and enclosure. Our preliminary data show that the edges of newly formed discs contain two distinct types of extracellular links: one connecting discs with the inner segment plasma membrane and another connecting disc edges between themselves. Experiments described in Aims 1 and 2 will be devoted to determining the protein composition of each link type and elucidating their specific roles in supporting the high fidelity of disc elongation and stacking. Aim 3 will focus on the final step in disc maturation consisting of its scission from the outer segment plasma membrane. We will address whether disc scission takes place exclusively in rods and explore molecular players involved in this process. Experiments described in this application will employ versatile molecular tools combined with the state-of-the-art three dimensional electron microscopy tomographic analysis of the outer segment structure. Addressing these mechanistic questions is essential for advancing our basic understanding of photoreceptor cell biology, as well as elucidating the pathophysiological mechanisms underlying inherited blindness frequently associated with defects in outer segment morphogenesis.

该提案中描述的实验解决了视觉领域最令人着迷的未解答问题之一 关于负责光感受器外节形态发生的分子机制的研究。这 外节是一种纤毛细胞器，可响应捕获光而产生电信号。一个独特的 外节的形态特征是它充满了一堆扁平的膜盘，提供了巨大的空间。 用于光子捕获和信号放大的表面。这种解剖结构的功能意义 很长一段时间以来，我们一直在认识光盘，但我们对光盘如何在分子水平上构建的理解仍然存在 令人沮丧的是简陋的。该应用解决了感光盘的几个鲜为人知的方面 形态发生，与椎间盘扩张、排列和包围的过程有关。我们的初步数据显示 新形成的椎间盘的边缘包含两种不同类型的细胞外链接：一种将椎间盘与 内部节段质膜和它们之间的另一个连接盘边缘。实验描述 目标 1 和 2 将致力于确定每种连接类型的蛋白质组成并阐明它们的作用 在支持椎间盘伸长和堆叠的高保真度方面具有特定作用。目标 3 将重点关注光盘的最后一步 成熟包括其从外段质膜的分裂。我们将解决是否有光盘 分裂仅发生在杆中，并探索参与此过程的分子参与者。实验 本申请中描述的将采用多功能分子工具与最先进的三种技术相结合 外节结构的三维电子显微镜断层扫描分析。解决这些问题 机制问题对于增进我们对感光细胞生物学的基本理解以及 阐明遗传性​​失明的病理生理机制，通常与缺陷相关 外节形态发生。