Cell-intrinsic mechanisms of presynaptic assembly

突触前组装的细胞内在机制

• 批准号: 10563190
• 负责人: PERI T KURSHAN
• 金额: $ 42万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10563190
• 关键词: Actins; Address; Affect; Alleles; Axon; Binding; Biological; Biological Models; Biology; Brain; Caenorhabditis elegans; Cell Adhesion; Cell Adhesion Molecules; Cells; Cues; Cytoskeleton; Data; Defect; Dependence; Development; Disease; Disparate; Functional disorder; Genetic; Goals; Growth Cones; In Vitro; Integral Membrane Protein; Intellectual functioning disability; Kidney; Kinesin; Knowledge; Mammals; Mediating; Modeling; Molecular; Molecular Motors; Motor; Mutation; Nematoda; Nervous System; Neurodevelopmental Disorder; Optics; Phase; Physical condensation; Polymers; Positioning Attribute; Process; Protein Biosynthesis; Protein Isoforms; Proteins; Publishing; Recording of previous events; Research; Role; Scaffolding Protein; Schizophrenia; Signal Transduction; Site; Stereotyping; Synapses; Synaptic Cleft; System; Testing; Therapeutic Intervention; Translations; Vesicle; autism spectrum disorder; extracellular; genetic approach; imaging approach; in vivo; information processing; innovation; mutant; nephrin; neural circuit; neuronal circuitry; neuropsychiatric disorder; new therapeutic target; novel therapeutic intervention; podocyte; polymerization; preservation; presynaptic; programs; protein transport; recruit; scaffold; synaptic function; synaptogenesis; trafficking

PI: Kurshan, Peri T. PROJECT SUMMARY/ABSTRACT Synapses are the fundamental information processing units in the brain and their dysfunction leads to neurodevelopmental and neuropsychiatric disorders. Synapse development and organization is mediated in part by a class of transmembrane proteins called synaptic cell-adhesion molecules (sCAMs), and mutations in sCAM genes is highly associated with diseases such as autism, schizophrenia and intellectual disability, among others. The dominant model for synapse formation suggests that it is initiated by the trans-synaptic binding of sCAMs, however in vivo evidence for that model is lacking. Here we propose to uncover non-trans- synaptic cell-intrinsic molecular programs for presynaptic assembly that mediate the localization, trafficking and subcellular functions of sCAMs and other integral presynaptic proteins. Our preliminary evidence suggests that the intracellular domains of the presynaptic sCAMs neurexin and syg-2/nephrin are cell-autonomously required for presynaptic organization. Moreover, we find that the localization of neurexin to the presynaptic active zone is mediated by intracellular interactions with active zone scaffold proteins and kinesin motors. Finally, we have found that the dependence of sCAMs and other active zone proteins on transport by kinesins depends on the stage of axonal outgrowth. Based on these findings, we hypothesize that presynaptic assembly is mediated in large part by cell-intrinsic mechanisms. We propose to pursue three Specific Aims to characterize the mechanisms that govern (1) the intracellular recruitment of sCAMs, (2) the intracellular organization of proper synapse spacing by sCAM-mediated cytoskeletal rearrangement, and (3) the delivery and reallocation of sCAMs and other active zone proteins by kinesin- dependent and independent mechanisms at different stages of axonal outgrowth (Aim 3). To investigate these hypotheses, we leverage the genetic tractability and stereotyped nervous system of the nematode C. elegans, along with innovative imaging and genetic approaches. C. elegans has a long history of revealing fundamental synaptic biology and our previous published results and preliminary data position us well to take advantage of the power of this system. Collectively our proposed research will reveal how cell-intrinsic mechanisms govern the function of sCAMs in synapse formation. These studies have the potential to uncover the molecular mechanisms underlying neurodevelopmental disorders that result from defects in sCAM function, and thus provide targets for the development of specific therapeutic interventions.

PI：Kurshan，Peri T. 项目概要/摘要 突触是大脑中基本的信息处理单元，它们的功能障碍会导致 神经发育和神经精神疾病。突触的发育和组织是介导的 部分是由一类称为突触细胞粘附分子（sCAM）的跨膜蛋白和 sCAM基因与自闭症、精神分裂症和智力障碍等疾病高度相关， 除其他外。突触形成的主要模型表明它是由跨突触启动的 sCAM 的结合，但是缺乏该模型的体内证据。在这里，我们建议揭露非反式 用于突触前组装的突触细胞内在分子程序，介导定位、运输和 sCAM 和其他完整突触前蛋白的亚细胞功能。 我们的初步证据表明，突触前 sCAM 的细胞内结构域神经毒素和 syg-2/nephrin 是突触前组织细胞自主所需的。此外，我们发现 神经素在突触前活性区的定位是通过细胞内与活性区的相互作用介导的 支架蛋白和驱动蛋白马达。最后，我们发现 sCAM 和其他活性物质的依赖性 驱动蛋白运输的区域蛋白取决于轴突生长的阶段。基于这些发现，我们 假设突触前组装在很大程度上是由细胞内在机制介导的。我们建议 追求三个具体目标来描述控制 (1) 细胞内招募的机制 sCAM，(2) sCAM 介导的细胞骨架在细胞内组织适当的突触间距 重排，以及 (3) sCAM 和其他活性区蛋白通过驱动蛋白的递送和重新分配 轴突生长不同阶段的依赖和独立机制（目标 3）。 为了研究这些假设，我们利用了遗传易处理性和刻板的神经系统 线虫秀丽隐杆线虫，以及创新的成像和遗传方法。线虫有很长的 揭示基础突触生物学的历史以及我们之前发表的结果和初步数据 让我们能够很好地利用这个系统的力量。总的来说，我们提出的研究将揭示 细胞内在机制如何控制 sCAM 在突触形成中的功能。这些研究有 揭示神经发育障碍引起的分子机制的潜力 sCAM 功能缺陷，从而为开发特定的治疗干预措施提供目标。