Regulation of protein targeting in axon guidance and neuronal morphogenesis

轴突引导和神经元形态发生中蛋白质靶向的调节

• 批准号: 9069619
• 负责人: MARY C HALLORAN
• 金额: $ 32.73万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9069619
• 关键词: Afferent Neurons; Alzheimer' s Disease; Axon; Axonal Transport; Behavior; Binding; Biosensor; Carrier Proteins; Cell membrane; Cells; Charcot-Marie-Tooth Disease; Complex; Cues; Data; Defect; Dendrites; Development; Disease; Dynein ATPase; Embryo; Endosomes; Environment; Event; Goals; Health; Human; Image; Individual; Kinesin; Label; Learning; Life; Ligands; Link; Location; Maintenance; Mediating; Mediator of activation protein; Membrane; Membrane Protein Traffic; Memory; Microtubules; Modeling; Molecular; Molecular Target; Morphogenesis; Morphology; Motor; Natural regeneration; Neurodegenerative Disorders; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 3; Neurotrophin 3; Niemann-Pick Diseases; PHluorin; Pain Disorder; Peripheral; Process; Protein Family; Proteins; Regulation; Role; Route; Semaphorin-3A; Semaphorins; Sensory; Signal Transduction; Slide; Structure; System; Testing; Time; Vesicle; Vesicle Transport Pathway; Zebrafish; axon growth; axon guidance; axon injury; extracellular; in vivo; in vivo Model; knock-down; mutant; neural circuit; neuron development; neuronal transport; neurotrophic factor; novel; painful neuropathy; polymerization; protein function; protein transport; receptor; research study; response; synaptogenesis; targeted imaging; temporal measurement; trafficking

 DESCRIPTION (provided by applicant): Proper development of neuronal morphology and neural circuits, as well as neuronal maintenance, requires tightly controlled subcellular localization of proteins such as axon guidance cue receptors. Proteins are targeted to specific cell locations by elaborate membrane trafficking and axonal transport systems. Neurons are particularly dependent on high fidelity protein trafficking because of their highly polarized and complex structure. Defects in trafficking and transport underlie multiple human developmental and neurodegenerative diseases, including Alzheimer's disease, Charcot-Marie-Tooth, and Niemann Pick disease. Despite their importance, the mechanisms regulating trafficking processes in neurons are poorly understood, in part due to a paucity of in vivo models in which the machinery and mechanisms of axon transport can be studied. A major challenge to the field and the long term goal of this project is to understand the mechanisms controlling axonal transport and protein localization as neurons develop in their natural environment, where they must integrate multiple extracellular cues. We established a model in which we can image dynamics of neuronal cargo transport, protein localization, and microtubule behavior in the intact zebrafish embryo. Vertebrate sensory neurons extend distinct central and peripheral axons to form the sensory circuit. We found that these axons show distinct responses to axon guidance cues. Moreover, we discovered roles for endosomal trafficking and the kinesin adaptor Calsyntenin-1 (Clstn-1) in differential guidance of sensory axons. In Aim 1 we propose to determine how calsyntenins regulate endosome transport routes to different axon compartments. In Aim 2 we will investigate mechanisms regulating specific localization of receptors for Neurotrophin-3 and Semaphorin3d. We will test the hypothesis that Calsyntenins and another class of kinesin adaptors, the Collapsin response mediator proteins (CRMPs) function to target receptors to specific axon compartments. In Aim 3 we will determine how Clstn-1 and CRMPs organize microtubule polarity and dynamics, processes essential for accurate trafficking and axon growth. Our unique model allows us to connect the molecular events of axonal transport, guidance receptor localization and microtubule organization to specific axon guidance decisions at the time and place they naturally occur. Elucidation of the molecular signals regulating sensory axon growth, guidance, and protein trafficking is critical for understanding neurodegenerative disorders, neuropathic pain disorders and the conditions under which regeneration after axon injury can occur. Our experiments will uncover such mechanisms and thus may help to identify molecular targets for disease treatment.

 描述（由申请人提供）：神经元形态和神经回路的适当发育以及神经元的维持需要严格控制蛋白质（如轴突导向因子受体）的亚细胞定位。蛋白质通过精细的膜运输和轴突运输系统靶向特定的细胞位置。神经元由于其高度极化和复杂的结构而特别依赖于高保真蛋白质运输。运输和运输缺陷是多种人类发育和神经退行性疾病的基础，包括阿尔茨海默病、腓骨肌萎缩症和尼曼皮克病。尽管它们的重要性，调节神经元中的运输过程的机制知之甚少，部分原因是缺乏体内模型，其中轴突运输的机械和机制可以进行研究。该领域的一个主要挑战和该项目的长期目标是了解神经元在其自然环境中发育时控制轴突运输和蛋白质定位的机制，在那里它们必须整合多种细胞外信号。我们建立了一个模型，在这个模型中，我们可以对完整的斑马鱼胚胎中神经元货物运输、蛋白质定位和微管行为的动态进行成像。脊椎动物感觉神经元延伸不同的中枢和外周轴突，形成感觉回路。我们发现，这些轴突显示出不同的反应轴突的指导线索。此外，我们发现了内体运输和驱动蛋白适配器Calsyntenin-1（Clasmodin-1）在感觉轴突的差异指导中的作用。在目的1中，我们提出了确定如何calsyntenins调节内体运输路线不同的轴突隔室。在目标2中，我们将研究调节神经营养素-3和脑信号蛋白3d受体特异性定位的机制。我们将测试这一假设，即Calsyntenins和另一类驱动蛋白衔接子，塌陷蛋白反应介体蛋白（CRMPs）的功能，以靶向受体的特定轴突隔室。在目标3中，我们将确定Climate-1和CRMPs如何组织微管极性和动力学，这是精确运输和轴突生长所必需的过程。我们独特的模型使我们能够将轴突运输，指导受体定位和微管组织的分子事件与它们自然发生的时间和地点的特定轴突指导决策联系起来。阐明调控感觉轴突生长、引导和蛋白质运输的分子信号对于 了解神经退行性疾病，神经性疼痛疾病和轴突损伤后再生可能发生的条件。我们的实验将揭示这些机制，从而有助于确定疾病治疗的分子靶点。