Molecular determinants and function of axonal actin assemblies

轴突肌动蛋白组件的分子决定因素和功能

• 批准号: 9981838
• 负责人: Subhojit Roy
• 金额: $ 34.67万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9981838
• 关键词: Actin-Binding Protein; Actins; Address; Algorithms; Architecture; Attenuated; Axon; Axonal Transport; Biological Assay; Biological Models; Biology; Caenorhabditis elegans; Cell membrane; Cells; Cellular biology; Clustered Regularly Interspaced Short Palindromic Repeats; Cytoskeletal Modeling; Cytoskeleton; DNA; Data; Defect; Distal; EMS1 gene; Endosomes; Eukaryota; Event; Filament; Generations; Goals; Growth Cones; Homeostasis; Image; Investments; Knowledge; Learning; Light; Maintenance; Metabolic; Microfilaments; Microfluidics; Microscopic; Microscopy; Microtubules; Molecular; Mutation; Names; Neurobiology; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neurons; Pattern; Periodicity; Pharmacology Study; Physiological; Polymers; Protein Family; Proteins; Reporting; Research Personnel; Resolution; Role; Signal Transduction; Stains; Structure; Surface; Synapses; Techniques; Testing; Vesicle; Visualization; autism spectrum disorder; base; beta Actin; cofilin; depolymerization; experimental study; fascinate; human disease; in vivo; in vivo Model; insight; knock-down; light microscopy; migration; monomer; novel; presynaptic; small hairpin RNA; synaptic function

The overall goal of this application is to clarify the molecular organization and function of enigmatic axonal actin assemblies that my lab recently discovered. Actin organization along axon shafts has been relatively ignored for decades, probably because routine staining – using the classic actin-filament marker phalloidin – only shows a patchy, uninteresting pattern. However, recent studies from us and others' using super-resolution microscopy and low-light imaging have revealed a hidden world of actin in axon shafts – replete with elaborate circumferential rings underneath the plasma membrane, and rapidly elongating linear filaments along the axis of the axon shaft. We have been fortunate to be at the forefront of these discoveries, and our studies have revealed fascinating actin dynamics in axons. Specifically, we found that axons have focal “hotspots” of actin – spaced ~ 3-4 µm apart – where actin continuously polymerizes and depolymerizes. These hotspots give rise to long actin filaments that rapidly (and bidirectionally) elongate along the axon shaft (we named these “actin trails”). Actin rings, trails and hotspots are seen in axons in vivo, and we will use in vivo model systems in this proposal as well. Although the overall assemblies have been seen, molecular events underlying the generation and maintenance of these structures is unclear. Importantly, their functional roles in axons are unknown. Here we propose three specific aims to clarify the organization and function of these newly-discovered actin assemblies: Aim #1: Identify mechanisms initiating actin trails in axons. Aim #2: Identify mechanisms elongating actin trails in axons. Aim #3: Determine functions of axonal actin assemblies.

该应用的总体目标是阐明神秘的轴突肌动蛋白的分子组织和功能 我的实验室最近发现的集会。沿轴突轴的肌动蛋白组织被相对忽略 几十年来，可能是因为常规染色 - 使用经典的肌动蛋白丝标记杆菌 - 仅显示一个 斑点，无趣的模式。但是，使用超分辨率显微镜的我们和其他人的最新研究 低光成像揭示了轴突轴中隐藏的肌动蛋白世界 - 用精致的圆周代替 在质膜下方的环，并沿轴突轴的轴迅速拉长线性丝。 我们很幸运地站在这些发现的最前沿，我们的研究表明很有趣 轴突中的肌动蛋白动力学。特别是，我们发现轴突具有肌动蛋白的焦点“热点” - 间隔〜3-4 µm - 肌动蛋白不断聚合和解聚。这些热点产生了长长的肌动蛋白丝 沿轴突轴迅速（并在双向上）伸长（我们命名了这些“肌动蛋白小径”）。肌动蛋白戒指，步道和 在体内轴突中可以看到热点，我们也将在该建议中使用体内模型系统。虽然 已经看到了整体组件，这些分子事件是这些生成和维护的基础 结构尚不清楚。重要的是，它们在轴突中的功能作用尚不清楚。在这里，我们提出了三个特定的 旨在阐明这些新发现的肌动蛋白组件的组织和功能：AIM＃1：确定 机制启动轴突的肌动蛋白步道。 AIM＃2：确定轴突中肌动蛋白跟踪拉长的机制。目的 ＃3：确定轴突肌动蛋白组件的功能。