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

• 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
• 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

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.

项目总结/摘要 神经元之间有效的突触通讯需要精确的突触前跨细胞排列， 末端有突触后特化。神经递质释放和检测的部位不是 相反，活性区释放机制是局部富集的，并且精确地跨突触排列 局部富集的突触后支架和受体。最近，超分辨率显微镜方法 揭示了许多对突触传递至关重要的蛋白质不是均匀分布的，而是高度分布的。 富含突触下结构域（SSD）。这些SSD对齐以形成跨突触纳米柱， 通常被认为调节突触传递的功效。一个突出的问题是：SSD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 被提议控制突触的纳米级组织，因为它们跨越突触间隙， 能够通过细胞内和细胞外序列参与双向信号传导。突显 由于粘附分子的重要性，编码这些蛋白质的基因突变通常与粘附分子有关。 精神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， 在突触周围，突触前粘附蛋白的内源性操纵还没有揭示出一种新的机制。 这些分子在控制跨突触SSD属性的指导作用。使用3D dSTORM 在超分辨率成像中，我们已经确定neurexin-3（Nrxn 3）是第一个neurexin和第一个突触前蛋白。 这种粘附分子是兴奋性突触的纳米级组织所必需的。条件性消融 neurexin-3在原代海马培养物中显著降低了突触密度、体积和 活动区和突触后SSD的跨突触对齐。我们假设不同的Nrxn 3信号传导 序列控制SSD特性和纳米柱排列，neurexin-3形成突触前SSD 与突触后致密SSD直接对齐。这一建议建立在我们的初步和公布的数据基础上 neurexin-3是突触下组织所必需，对AMPAR介导的突触 传输我们将利用3D dSTORM成像，分子结构/功能方法和小鼠 遗传学来检验我们的假设在两个特定的目标。首先，我们将直接研究neurexin-3在 AMPA受体SSD在兴奋性突触和系统地进行结构/功能实验， 确定neurexin-3的细胞内和细胞外信号序列所需的纳米 组织和SSD对齐。其次，我们将研究突触下定位和跨突触 内源性neurexin-3的排列。总之，我们的研究结果将为neurexin-3 信号调控突触下结构以及neurexin-3功能障碍如何导致病因 神经精神发育和物质使用障碍的基础。