Control of neural circuit assembly by cell surface protein interactions

通过细胞表面蛋白质相互作用控制神经回路组装

• 批准号: 10443123
• 负责人: Engin Ozkan
• 金额: $ 56.66万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10443123
• 关键词: Address; Affect; Affinity; Area; Avidity; Binding; Birth; Brain; Cell Adhesion Molecules; Cell Communication; Cell Surface Proteins; Cell surface; Cells; Dendrites; Development; Disease; Drosophila genus; Family; Genes; Goals; Human; Immunoglobulins; In Vitro; Individual; Interneurons; Invertebrates; Lead; Ligands; Mammals; Maps; Measures; Mediating; Methods; Muscle; Nervous system structure; Neurons; Neuropil; Optic Lobe; Outcome; Pattern; Presynaptic Terminals; Protein Tyrosine Phosphatase; Proteins; Publishing; Pupa; Receptor Signaling; Research; Research Project Grants; Role; Side; Signaling Molecule; Specific qualifier value; Structure; Sum; Surface Plasmon Resonance; Synapses; System; To specify; Variant; Visual; Work; axon guidance; cell assembly; connectome; early screening; human disease; improved; in vivo; insight; mutant; nanoparticle; nerve supply; nervous system development; neural circuit; neuromuscular system; neuron loss; neuroregulation; neurotransmission; postsynaptic; presynaptic; programs; receptor; screening; synaptogenesis

Project Summary/Abstract In both invertebrate and vertebrate nervous systems, cell recognition molecules control assembly of synaptic circuits during development. We discovered a network of interacting cell surface proteins (CSPs) through an in vitro binding (“interactome”) screen for interactions among all Drosophila immunoglobulin superfamily (IgSF) proteins. In this network, 11 DIP proteins in one IgSF subfamily interact with 21 Dpr proteins in another subfamily, with affinities ranging from 1 µM to 200 µM. Each DIP and Dpr is expressed by a unique subset of neurons in each area of the developing brain. The connectome of the Drosophila pupal optic lobe (OL) is assembled by activity-independent mechanisms. DIP::Dpr interactions are important for OL and neuromuscular system wiring, and loss of individual DIPs or Dprs can alter synaptic connectivity and cause neuronal death. In this proposal, we address the functions of affinity variation and avidity by examining how changes in DIP::Dpr binding affinity and expression level affect synaptic terminal development in the neuromuscular system and synaptic connectivity in the OL. We also examine other interaction networks that may be involved in determination of the optic lobe connectome. Two such networks are the Beat/Side network of 22 IgSF proteins, which we also discovered in the interactome screen, and a network of ligands for receptor tyrosine phosphatases (RPTPs), which are neuronal signaling receptors that regulate axon guidance and synaptogenesis. We will examine how these three networks work together in vivo to control synaptic connectivity between specific lamina and medulla neurons in the OL. We will generate a comprehensive map of interactions and measure binding affinities for all of the Beat/Side proteins using surface plasmon resonance. To validate interactions in the RPTP network and identify inter-network interactions, we will develop a method for multiplexed interactome screening using high-avidity 60-mer nanoparticles that may be able to identify lower-affinity interactions missed in earlier screens. The objectives of the present application are to define how the affinities of DIP::Dpr interactions affect synaptic connection patterns, to examine how DIPs and Dprs work together with other families of cell recognition molecules, and to develop improved methods to detect and characterize in vitro interactions among CSPs. We plan to attain these objectives through three Specific Aims. Aim 1: Define the functions of DIP::Dpr affinity variation in control of muscle innervation. Aim 2: Examine the roles of DIP::Dpr affinity and of interplay among cell adhesion and signaling molecules in determination of synaptic connectivity in the OL. Aim 3: Map in vitro interactions among Beats, Sides, RPTPs, and other CSPs. The expected outcome of the proposed research will be the acquisition of new insights into the mechanisms by which interactions among cell recognition molecules control the assembly of neural circuits. This will have a significant positive impact by increasing our understanding of conserved mechanisms involved in nervous system development, some of which are affected by disease.

项目总结/摘要 在无脊椎动物和脊椎动物的神经系统中，细胞识别分子控制突触的组装， 开发过程中的电路我们发现了一个相互作用的细胞表面蛋白（CSP）网络， 体外结合（“相互作用组”）筛选所有果蝇免疫球蛋白超家族（IgSF）之间的相互作用 proteins.在这个网络中，一个IgSF亚家族中的11个DIP蛋白与另一个IgSF亚家族中的21个Dpr蛋白相互作用 亚家族，亲和力范围为1 µM至200 µM。每个DIP和Dpr由以下的唯一子集表示： 发育中的大脑的各个区域的神经元。果蝇蛹视叶（OL）的连接体是 由独立于活动的机制组装。DIP：：Dpr相互作用对OL和神经肌肉非常重要 系统布线以及个别DIP或DIPs的丢失可以改变突触连接并导致神经元死亡。在 在这个提议中，我们通过研究DIP：：Dpr的变化来解决亲和力变化和亲和力的功能 结合亲和力和表达水平影响神经肌肉系统中的突触末端发育， 突触的连接。我们还研究了其他可能涉及的相互作用网络， 视叶连接体的测定。两个这样的网络是22个IgSF蛋白的Beat/Side网络， 我们在相互作用组筛选中也发现了这种蛋白， 磷酸酶（RPTP），其是调节轴突引导的神经元信号传导受体， 突触发生我们将研究这三个网络如何在体内共同作用来控制突触 在OL中特定板层和髓质神经元之间的连接。我们将生成一个全面的地图 的相互作用，并使用表面等离子体共振测量所有Beat/Side蛋白的结合亲和力。 为了验证RPTP网络中的交互并识别网络间交互，我们将开发一种方法 对于使用高亲合力60聚体纳米颗粒的多重相互作用组筛选， 较低亲和力的交互在早期的筛选中被遗漏。本申请的目的是定义如何 DIP：：Dpr相互作用的亲和力影响突触连接模式，以检查DIP和Dpr如何工作 以及其他家族的细胞识别分子，并开发改进的方法来检测和 表征CSP之间的体外相互作用。我们计划通过三个具体目标来实现这些目标。 目的1：明确DIP：：Dpr亲和力变化在肌肉神经支配调控中的作用。目标2：检查 DIP：：Dpr亲和力以及细胞粘附和信号分子之间的相互作用在确定 OL中的突触连接。目的3：绘制Beats、Sides、RPTP和其他CSP之间的体外相互作用。 拟议研究的预期成果将是获得对机制的新见解， 细胞识别分子之间的相互作用控制着神经回路的组装。这将产生 通过增加我们对神经系统中保守机制的理解， 系统发展，其中一些受到疾病的影响。