Organization and function of neuronal endosomes

神经元内体的组织和功能

• 批准号: 8729515
• 负责人: Bettina R Winckler
• 金额: $ 34.22万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8729515
• 关键词: Address; Affect; Alzheimer' s Disease; Autistic Disorder; Axon; Brain; Cell Adhesion Molecules; Data; Defect; Dendrites; Development; Disease; Down-Regulation; Early Endosome; Electron Microscopy; Endocytosis; Endosomes; Fibroblasts; Fluorescence Microscopy; Functional disorder; Future; Gene Family; Goals; Golgi Apparatus; Grant; Growth; Health; Image; Integral Membrane Protein; Intervention; Knowledge; Lead; Length; Life; Link; Location; Lysosomes; Mass Spectrum Analysis; Mediating; Membrane; Membrane Protein Traffic; Membrane Proteins; Modeling; Molecular; Mus; Mutation; Names; Nervous system structure; Neural Cell Adhesion Molecule L1; Neurons; Outcome; Pathology; Physiological; Play; Process; Proteins; Recycling; Regulation; Research; Resolution; Rodent; Role; Signal Transduction; Site; Sorting - Cell Movement; Surface; System; Testing; Vesicle; Work; Yeasts; arm; axon growth; axon guidance; base; functional outcomes; innovation; insight; member; neurodevelopment; neurological pathology; postsynaptic; prevent; public health relevance; receptor; receptor function; relating to nervous system; signal processing; synaptic function; trafficking

DESCRIPTION (provided by applicant): Endosomal trafficking of receptors plays fundamental roles in neuronal function and in neurodevelopment, as well as in disease states of the nervous system. The current understanding of endosome organization and function is based primarily on work in yeast and fibroblasts. However, our recent work showed that neurons employ neuronal-specific endocytic and endosomal machinery. There is thus presently a fundamental gap in the understanding of how endosomal function is adapted to cater to the specific physiological needs of neurons. Since the particular organization of the endosome determines postendocytic trafficking of receptors (i.e. signaling, processing, and/or degradation) and thereby specific functional outcomes, the field's ignorance of the neuronal adaptations of the endosomal system constitutes a significant barrier to progress in both basic and disease-oriented fields. Our long-term goals are to uncover the functional contributions of endosomes to neurodevelopment, and to the healthy and diseased brain. The rationale motivating this proposal is that vertebrate neurons express neuronal-specific proteins in their endosomes (in particular NEEP21/Nsg-1 and P19/Nsg-2) that control the endosomal trafficking of crucial neuronal membrane proteins, such as receptors important in development (the axonal adhesion molecule L1/NgCAM), synaptic function (GluA2), and disease (bAPP). Nsg-proteins are members of a gene family of transmembrane proteins found specifically in the neuronal Golgi and in poorly characterized somatodendritic endosomes ("Nsg-endosomes"). The central concept of this application is that crucial neuronal functions depend on Nsg-endosomes. Our preliminary data suggest the specific hypothesis that Nsg-proteins maintain a specific subset of endocytosed receptors in a distinct non-degradative compartment from where the cargo can recycle to multiple locations to regulate axon growth and synaptic function. We will use innovative approaches including quantitative single vesicle live imaging, super-resolution fluorescence microscopy, and electron microscopy in combination with functional interference approaches in primary neurons and in rodent cortex to address three specific aims: Aim 1) How are Nsg-endosomes formed and how do they relate to other somatodendritic endosomes? With which other proteins does NEEP21/Nsg-1 interact and which rabs regulate Nsg-endosomal organization? Aim 2) How does loss of NEEP21/Nsg-1 and P19/Nsg-2 affect endosomal organization and cargo trafficking? Aim 3) Does loss of NEEP21/Nsg-1 and P19/Nsg-2 affect axon and dendrite development in the cortex? The proposed research is significant because it will discover the contribution of endosomes to neuronal function in health and disease. The new insights gained will not only lead to fundamental advances in understanding the regulation of neuronal membrane traffic, but also raise the possibility of new targets for tailoring translational strateges in the future.

描述(由申请人提供)：受体的内体转运在神经功能和神经发育以及神经系统的疾病状态中发挥着基础作用。目前对内小体组织和功能的了解主要是基于酵母和成纤维细胞的工作。然而，我们最近的工作表明，神经元使用神经元特有的内吞和内吞机制。因此，目前在了解内体功能如何适应神经元的特定生理需求方面存在着根本的空白。由于内体的特定组织决定了受体的内吞后运输(即信号、处理和/或降解)，从而决定了特定的功能结果，该领域对内体系统的神经元适应的忽视构成了在基础领域和面向疾病的领域取得进展的重大障碍。我们的长期目标是揭示内体对神经发育以及对健康和患病大脑的功能贡献。提出这一建议的基本原理是脊椎动物神经元在其内体中表达神经元特异性蛋白(特别是NEEP21/NSG-1和P19/NSG-2)，这些蛋白控制着关键神经元膜蛋白的内体运输，如在发育中重要的受体(轴突黏附分子L1/NgCAM)、突触功能(GluA2)和疾病(BAPP)。NSG-蛋白是一个跨膜蛋白基因家族的成员，该基因家族专门存在于神经元高尔基体和特征较差的躯体树突内体(NSG-Enosome)中。这一应用的中心概念是，关键的神经元功能依赖于NSG-内小体。我们的初步数据表明，特定的假设是，NSG-蛋白在一个独特的非降解性隔室中维持特定的内吞受体亚集，从那里货物可以循环到多个位置，以调节轴突生长和突触功能。我们将使用创新的方法，包括定量单囊泡实时成像、超分辨率荧光显微镜和电子显微镜，并结合初级神经元和啮齿动物皮质的功能干扰方法来解决三个特定目标：目的1)NSG内体是如何形成的，它们与其他躯体树突状内体之间是如何联系的？NEEP21/NSG-1与哪些其他蛋白相互作用，以及哪些RAB调节NSG内体组织？目的2)NEEP21/NSG-1和P19/NSG-2基因缺失对内体组织和货物贩运有何影响？目的3)NEEP21/NSG-1和P19/NSG-2的缺失是否影响皮质轴突和树突的发育？这项拟议的研究意义重大，因为它将发现内小体在健康和疾病中对神经元功能的贡献。所获得的新见解不仅将导致在理解神经元膜交通调节方面的根本性进展，而且还将增加未来定制翻译策略的新靶点的可能性。