Control of subsynaptic domain organization and nanocolumn alignment by neurexin-3

neurexin-3 控制突触亚域组织和纳米柱排列

基本信息

批准号：
10429177
负责人：
Jason Aoto
金额：
$ 22.33万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-04 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10429177
关键词：
3-Dimensional AMPA Receptors Ablation Address Adhesions Alternative Splicing Architecture Biology Brain Brain region Cell Adhesion Molecules Characteristics Communication Confocal Microscopy DLG4 gene Data Data Analyses Data Collection Detection Ensure Epitopes Essential Genes Etiology Excitatory Synapse Exhibits Exons Functional disorder Genes Genetic Genomics Hippocampus (Brain)Image Individual Inhibitory Synapse Instruction Knockout Mice Knowledge Lead Ligands Link Maintenance Mediating Mental Health Mental disorders Microscopy Molecular Molecular Structure Mus Mutation N-Methyl-D-Aspartate Receptors Neurons Peptide Signal Sequences Phenotype Play Presynaptic Terminals Property Protein Isoforms Proteins Publishing Resolution Role Schizophrenia Sequence Homology Signal Transduction Site Structure Substance Use Disorder Synapses Synaptic Cleft Synaptic Transmission Testing Work autism spectrum disorder cell type conditional knockout density experimental study extracellular insight interest mouse genetics nano nanocolumn nanoscale neuropsychiatry neurotransmitter release postsynaptic postsynaptic density protein presynaptic promoter receptor scaffold stress disorder synaptic function synaptogenesis tool trafficking

项目摘要

Project Summary/Abstract Efficient synaptic communication between neurons requires precise transcellular alignment of the presynaptic terminal with the postsynaptic specialization. The sites of neurotransmitter release and detection are not random; instead the active zone release machinery is locally enriched and precisely aligned transsynaptically with locally enriched postsynaptic scaffolds and receptors. Recently, super-resolution microscopy approaches have revealed that many proteins critical for synaptic transmission are not uniformly distributed but highly enriched in subsynaptic domains (SSDs). These SSDs are aligned to form transsynaptic nanocolumns that are commonly thought to regulate the efficacy of synaptic transmission. An outstanding question is: how are SSDs regulated, localized and aligned into transsynaptic nanocolumns? Transsynaptic cell adhesion molecules have been proposed to control the nanoscale organization of synapses because they span the synaptic cleft and are capable of participating in bidirectional signaling via intracellular and extracellular sequences. Underscoring the importance of adhesion molecules, mutations in genes that encode these proteins are commonly linked to mental health and substance use disorders. While adhesion molecules studied thus far cluster in SSDs in or around the synapse, the endogenous manipulation of presynaptic adhesion proteins has yet to reveal an instructive role for these molecules in controlling transsynaptic SSD properties. Using 3D dSTORM superresolution imaging, we have identified neurexin-3 (Nrxn3) as the first neurexin and first presynaptic adhesion molecule necessary for the nanoscale organization of excitatory synapses. Conditional ablation of neurexin-3 in primary hippocampal cultures significantly reduced the synaptic density, volume and transsynaptic alignment of active zone and postsynaptic SSDs. We hypothesize that distinct Nrxn3 signaling sequences govern SSD properties and nanocolumn alignment and that neurexin-3 forms presynaptic SSDs directly aligned with postsynaptic density SSDs. This proposal builds on our preliminary and published data that neurexin-3 is necessary for subsynaptic organization and critical for AMPAR-mediated synaptic transmission. We will utilize 3D dSTORM imaging, molecular structure/function approaches and mouse genetics to test our hypothesis in two specific aims. First, we will directly examine the role of neurexin-3 on AMPA-receptor SSDs at excitatory synapses and systematically perform structure/function experiments to determine the intracellular and extracellular signaling sequences of neurexin-3 required for nanoscale organization and SSD alignment. Second, we will investigate the subsynaptic localization and transsynaptic alignment of endogenous neurexin-3. Together, our findings will provide critical insight into how neurexin-3 signaling governs subsynaptic architecture and how dysfunction of neurexin-3 can contribute to the etiologies that underlie neuropsychiatric, neurodevelopmental and substance use disorders.

项目概要/摘要神经元之间有效的突触通讯需要突触前的精确跨细胞对齐具有突触后特化的末端。神经递质释放和检测的位点不随机的;相反，活性区释放机制是局部丰富的，并且跨突触精确对齐具有局部丰富的突触后支架和受体。最近，超分辨率显微镜方法研究表明，许多对突触传递至关重要的蛋白质并不是均匀分布的，而是高度分布的。富含突触亚域（SSD）。这些 SSD 排列形成跨突触纳米柱，通常认为调节突触传递的功效。一个悬而未决的问题是：SSD 性能如何？调节、定位并排列成跨突触纳米柱？跨突触细胞粘附分子具有被提议用来控制突触的纳米级组织，因为它们跨越突触间隙并且能够通过细胞内和细胞外序列参与双向信号传导。强调粘附分子的重要性，编码这些蛋白质的基因突变通常与心理健康和物质使用障碍。虽然迄今为止研究的粘附分子在 SSD 中聚集，但在突触周围，突触前粘附蛋白的内源性操纵尚未揭示出这些分子在控制突触 SSD 特性方面发挥着指导作用。使用 3D dSTORM 超分辨率成像，我们已经确定 neurexin-3 (Nrxn3) 是第一个神经素和第一个突触前蛋白兴奋性突触的纳米级组织所必需的粘附分子。有条件消融原代海马培养物中的 neurexin-3 显着降低了突触密度、体积和活动区和突触后 SSD 的突触对齐。我们假设不同的 Nrxn3 信号传导序列控制 SSD 属性和纳米柱排列，并且 neurexin-3 形成突触前 SSD 直接与突触后密度 SSD 对齐。该提案基于我们的初步和已发布的数据 neurexin-3 对于亚突触组织是必需的，并且对于 AMPAR 介导的突触至关重要传播。我们将利用 3D dSTORM 成像、分子结构/功能方法和鼠标遗传学在两个特定目标上检验我们的假设。首先，我们将直接检查 neurexin-3 对兴奋性突触处的 AMPA 受体 SSD 并系统地进行结构/功能实验确定纳米级所需的 neurexin-3 的细胞内和细胞外信号序列组织和 SSD 对齐。其次，我们将研究突触亚定位和跨突触内源性神经毒素-3的比对。总之，我们的研究结果将为 Neurexin-3 如何信号传导控制突触亚结构以及 neurexin-3 功能障碍如何导致病因是神经精神、神经发育和物质使用障碍的基础。