The role of a novel viral-like signalling pathway in synaptic plasticity and neurological disorders

新型病毒样信号通路在突触可塑性和神经系统疾病中的作用

• 批准号: 9802983
• 负责人: Travis Thomson
• 金额: $ 36.64万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9802983
• 关键词: 3' Untranslated Regions; Actins; Address; Amino Acid Sequence; Antibodies; Behavior; Binding; Biological Models; Capsid; Cells; Co-Immunoprecipitations; Communication; Cytoskeleton; Degenerative Disorder; Development; Down-Regulation; Drosophila genus; Encapsulated; Epilepsy; Exhibits; Genes; Genetic; Genome; Goals; Grant; Homologous Gene; Human; Infectious Agent; Learning; Mammals; Mediating; Memory; Messenger RNA; Molecular; Multivesicular Body; Muscle; Nervous system structure; Neuromuscular Diseases; Neuromuscular Junction; Neuronal Plasticity; Neurons; Pathway interactions; Physiological; Play; Presynaptic Terminals; Proteins; RNA; RNA Interference; RNA immunoprecipitation sequencing; Reagent; Reporting; Research; Reticulum; Retrotransposon; Role; Schizophrenia; Selfish Genes; Signal Pathway; Signal Transduction; Spinocerebellar Ataxias; Synapses; Synaptic Vesicles; Synaptic plasticity; System; Testing; Transcript; Transfer RNA; Travel; Uncertainty; Ursidae Family; Viral; Viral Genome; Virus; WNT Signaling Pathway; Work; experimental study; extracellular vesicles; fly; gag Gene Products; human disease; intercellular communication; knock-down; nervous system disorder; neuromuscular; neuron development; neurotransmission; novel; particle; postsynaptic; presynaptic; protein function; trafficking; viral RNA

We have discovered a novel viral-like signaling pathway associated with extracellular vesicles (EV). We found the Drosophila homolog of ARC (Actin-Regulated Cytoskeleton-associated protein) (darc1), is present in EVs as both an mRNA and protein. ARC is a master regulator of synaptic plasticity in the nervous system of mammals and is crucial for learning and memory. dArc1 bears a domain resembling retroviral/retrotransposon Gag-like proteins that multimerizes into a capsid that packages viral RNA. Our work shows dARC1 forms a capsid, associates with its own RNA, and then transports the darc1 transcript across the synapse. The transfer of dArc1 is needed for activity-dependent plasticity at the fly neuromuscular junction (NMJ). Besides dArc1, it is unknown whether other genes are in this viral-like pathway. We address this uncertainty in Aim 1. Here we describe our plan to identify other Gag-like proteins in EVs, and we have already found another Gag protein enriched in EVs, that is encoded by the retrotransposon Copia. We have found that Copia transfers across the synaptic bouton. When copia is knocked down at the NMJ this strikingly leads to increased plasticity. This is the opposite of darc1, where we reported a decrease in plasticity. In Aim 2 we focus on what cargoes are co-transferring with dArc1 and Copia. We have identified through co-immunoprecipitation, mRNAs and proteins that associate with dArc1 and Copia. As to how the transfer of Arc occurs, we have found that the dArc1 3’untranslated region (UTR) is necessary and sufficient for the transfer of dArc1 across synaptic boutons. We are now testing if the dArc1 3’UTR directs the loading of dArc1 into EVs. As well, we propose experiments to understand how darc1 and copia mediate synaptic plasticity. We have co-immunoprecipitated dArc1 and Copia to identify potential interactors, and we will take a candidate approach to find genetic interactors. In preliminary work we found that dArc1 is needed for proper WNT pathway signaling at the NMJ. Additionally, we observe that Copia and dArc1 bind to some of the same proteins and mRNAs, suggesting that they may be antagonistic to each other, thus potentially explaining their seemingly opposite roles in mediating plasticity. Through this grant we will expand our understanding of EV trafficking and synaptic plasticity, while describing a novel physiological function of a retrotransposon in neuronal communication.

我们发现了一种与细胞外囊泡（EV）相关的新型病毒样信号通路。 发现了 ARC（肌动蛋白调节细胞骨架相关蛋白）（darc1）的果蝇同源物，是 ARC 以 mRNA 和蛋白质形式存在于 EV 中，是神经突触可塑性的主要调节因子。 dArc1 是哺乳动物的系统，对于学习和记忆至关重要。 逆转录病毒/逆转录转座子 Gag 样蛋白多聚成包装病毒 RNA 的衣壳。 研究表明 dARC1 形成衣壳，与其自身的 RNA 结合，然后运输 darc1 转录本 dArc1 的转移对于果蝇的活动依赖性可塑性是必需的。 除了 dArc1 之外，尚不清楚这种病毒样基因中是否存在其他基因。 我们在目标 1 中解决了这种不确定性。在这里，我们描述了识别其他类似 Gag 的计划。 EV 中的蛋白质，我们已经发现了另一种富含 EV 的 Gag 蛋白，它是由 逆转录转座子 Copia 当 copia 存在时，Copia 会跨过突触按钮。 在 NMJ 上被击倒，这显着地导致可塑性增加，这与 darc1 相反。 我们报告了可塑性的下降。在目标 2 中，我们重点关注哪些货物与 dArc1 共同转移以及 我们通过免疫共沉淀鉴定出与 dArc1 相关的 mRNA 和蛋白质。 至于Arc的转移是如何发生的，我们发现dArc1 3'非翻译区（UTR）。 对于 dArc1 跨突触纽扣的转移是必要且充分的，我们现在正在测试是否 dArc1 3’UTR 还指导将 dArc1 加载到 EV 中，我们还提出了实验来了解如何进行。 darc1 和 copia 介导突触可塑性。我们通过免疫共沉淀 dArc1 和 Copia 来鉴定。 潜在的相互作用者，我们将在前期工作中采取候选方法来寻找遗传相互作用者。 我们发现 dArc1 是 NMJ 正确 WNT 通路信号传导所必需的。此外，我们观察到。 Copia 和 dArc1 与一些相同的蛋白质和 mRNA 结合，表明它们可能是 彼此对立，从而可能解释它们在调节可塑性方面看似相反的作用。 通过这笔赠款，我们将扩大对 EV 贩运和突触可塑性的理解，同时 描述了逆转录转座子在神经通讯中的新生理功能。