IgSF protein interactions drive specificity in circuit wiring and synaptic elaboration

IgSF 蛋白质相互作用驱动电路布线和突触精细化的特异性

• 批准号: 10631084
• 负责人: Robert Arnulfo Carrillo
• 金额: $ 39.95万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10631084
• 关键词: Address; Affect; Affinity; Automobile Driving; Axon; Binding; Binding Proteins; Cell Communication; Cell Surface Proteins; Cells; Clinical; Code; Collaborations; Complex; Cues; Data; Development; Developmental Process; Disease; Drosophila genus; Dyslexia; Family; Foundations; Genes; Genetic; Goals; Growth; Homo; Human; Immunoglobulins; Individual; Link; Maps; Mediating; Modeling; Molecular; Morphology; Motor Activity; Motor Neurons; Multigene Family; Muscle; Nervous System; Neurobiology; Neurons; Pathway interactions; Pattern; Play; Positioning Attribute; Presynaptic Terminals; Process; Property; Proteins; Reagent; Regulation; Research; Resolution; Role; Schizophrenia; Shapes; Signal Pathway; Signal Transduction; Specific qualifier value; Specificity; Stereotyping; Structure; Synapses; Testing; Variant; Visual; Work; autism spectrum disorder; axon guidance; combinatorial; genetic approach; genetic manipulation; insight; member; mutant; nervous system disorder; neural; neural circuit; neuromuscular; neuromuscular system; novel; postsynaptic; presynaptic; programs; synaptic function; synaptogenesis

Project Summary In this application, we examine the molecular mechanisms that instruct neural wiring and axon terminal elaboration. We focus on the Drosophila neuromuscular system due to its invariant connectivity, limited synaptic partners, and accessibility. Given that this ‘simple’ circuit has been studied for over four decades, it is somewhat surprising that fundamental questions still exist as to how motor neurons choose their appropriate muscle targets and how each motor neuron develops a unique, yet stereotyped, axon terminal structure that underlies synaptic function. Conceptually, both of these developmental processes rely on specificity cues to guide synaptic partner matching (role 1) and synaptic elaboration at each axon terminal (role 2). In support of the first role, we previously discovered two interacting cell surface proteins (CSPs), DIP-α and Dpr10, that are required for wiring a motor neuron to a subset of muscles. In support of the second role, these CSPs continue to be expressed after connectivity, implying additional functions in synaptic development. Our central hypothesis is that combinatorial Dpr-DIP interactions, in addition to specifying synaptic connections, also participate in determining the structure and function of specified synapses. Insights into circuit development arose in a prior collaboration where we characterized the ‘Dpr-ome’, the set of interactions between two families of the immunoglobulin superfamily, the Dprs and DIPs. These 32 proteins bind to one another in unique combinations, and our preliminary data reveal unique expression patterns in the Drosophila larval neuromuscular circuit. Additionally, our data support a combinatorial Dpr-DIP interaction model that leverages cis/trans interactions to instruct highly specific synaptic partnerships. We also reveal a novel signaling pathway that underlies local synaptic elaboration. Given our findings and genetic reagents, we are in a unique position not only to compare axon branch-specific identification tags but also to ask if synaptic elaboration of neighboring axon terminals can be independently regulated. In the first aim, we capitalize on the Dpr-ome and the expression of 6 DIPs in multi-innervating motor neurons to perform single-cell genetic manipulations and examine how combinatorial Dpr-DIP codes instruct connectivity. In addition, we generate affinity variants to reveal a coordinated cis/trans interaction model that enhances specificity. In the second aim, we utilize functional and genetic approaches to understand how co-innervating inputs develop unique morphological and functional properties. We identify a novel crosstalk signaling pathway between axon arbors that locally sculpts NMJ size. Overall, these studies will uncover fundamental developmental programs required for neural circuit wiring and axon terminal elaboration, with emphasis on how CSP codes modulate each of these processes.

项目摘要 在这个应用程序中，我们研究的分子机制，指导神经布线和轴突终端 详细说明。我们专注于果蝇的神经肌肉系统，由于其不变的连接，有限的 突触伴侣和可接近性。考虑到这种“简单”的电路已经研究了四十多年， 有些令人惊讶的是，运动神经元如何选择合适的神经元， 肌肉靶点，以及每个运动神经元如何发展出独特的，但定型的轴突末端结构， 是突触功能的基础从概念上讲，这两个发展过程都依赖于特异性线索， 指导突触伴侣匹配（作用1）和每个轴突末端的突触加工（作用2）。支持 第一个作用，我们以前发现了两个相互作用的细胞表面蛋白（CSP），DIP-α和Dpr 10， 这是将运动神经元连接到肌肉子集所必需的。为了支持第二个作用，这些社区支助方案继续 在连接后表达，这意味着突触发育中的额外功能。我们的中央 假设是组合的Dpr-DIP相互作用，除了指定突触连接，还 参与决定特定突触的结构和功能。深入了解电路开发 在之前的一次合作中，我们描述了“Dpro-ome”，即两个人之间的相互作用集。 免疫球蛋白超家族的DIPs和DIP。这32种蛋白质相互结合， 独特的组合，我们的初步数据揭示了果蝇幼虫独特的表达模式， 神经肌肉回路此外，我们的数据支持组合Dpr-DIP相互作用模型， 顺式/反式相互作用指导高度特异性的突触伙伴关系。我们还揭示了一个新的信号通路 是局部突触精细化的基础鉴于我们的发现和基因试剂，我们处于一个独特的位置 不仅要比较轴突分支特异性识别标签，还要询问突触的精细化， 邻近的轴突终末可以独立调节。在第一个目标中，我们利用朝鲜， 在多神经支配的运动神经元中表达6种DIP，以进行单细胞遗传操作， 研究组合Dpr-DIP码如何指示连通性。此外，我们生成亲和变体， 揭示了一个协调的顺式/反式相互作用模型，增强特异性。在第二个目标中，我们利用 功能和遗传的方法来了解如何共同支配输入发展独特的形态和 功能特性我们确定了一种新的轴突乔木之间的串扰信号通路，局部雕刻 NMJ尺寸。总的来说，这些研究将揭示神经回路所需的基本发育程序。 布线和轴突终端的阐述，重点是CSP代码如何调制这些过程中的每一个。