SynDIG1/Prrt1 regulation of extrasynaptic GluA1-containing AMPARs during plasticity

SynDIG1/Prrt1 在可塑性过程中对突触外含 GluA1 AMPAR 的调节

基本信息

批准号：
10426207
负责人：
ELVA D DIAZ
金额：
$ 62.53万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-24 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10426207
关键词：
AMPA Receptors Acute Address Age Alzheimer&apos s Disease Biological Assay Brain Brain Diseases Cell surface Cells Chemicals Cognitive Color Complex Data Defect Down-Regulation Drug Targeting Electrophysiology (science)Epilepsy Etiology Exhibits Family Gene Family Genes Glycine Hippocampus (Brain)Image Integral Membrane Protein Investigation Knock-out Knockout Mice Knowledge Label Learning Long-Term Depression Long-Term Potentiation Maintenance Maps Mediating Membrane Proteins Memory Mental Depression Mental disorders Methods Microscopy Modeling Molecular Mus N-Methylaspartate Nervous system structure Neurons PHluorin Permeability Postsynaptic Membrane Proline Proteins Proteomics Regulation Resolution Role Schizophrenia Seizures Site Slice Stimulus Stroke Surface Synapses Synaptic Receptors Synaptic Transmission Synaptic plasticity Testing Tetanus Time Up-Regulation Variant Viral Wild Type Mouse Work cognitive skill density drug development in vivo insight interdisciplinary approach knock-down morris water maze mutant nervous system disorder neural network neuromechanism neuron loss neurotransmission novel object recognition postsynaptic pre-clinical presynaptic density protein 95 receptor receptor function recruit synaptic depression

项目摘要

Activity-dependent variation in synaptic AMPA receptor (AMPAR) content, referred to as ‘synaptic plasticity’, is a mechanism whereby information is stored in neural networks that give rise to higher order cognitive skills such as learning and memory. During long-term potentiation (LTP), a widely studied form of synaptic plasticity, extrasynaptic AMPARs are recruited from nearby reserve pools, including perisynaptic regions on the cell surface and intracellular compartments, and subsequent anchored with the postsynaptic density (PSD). A large body of evidence spanning decades of investigation has established mechanisms by which AMPARs are anchored within the PSD. In contrast, the molecular mechanisms that govern AMPAR synaptic targeting to establish reserve pools of extrasynaptic receptors are largely unknown. Given that recruitment of reserve pools of extrasynaptic AMPARs underlies the rapid strengthening of synapses that occurs during LTP, the molecular mechanisms that establish such reserve pools are critical to our understanding of synaptic plasticity and represent a major gap in our knowledge. SynDIG (Synapse Differentiation Induced Gene) defines a family of four genes (SynDIG1-4) that encode brain- specific transmembrane proteins. Here we will determine the function of SynDIG4 (SD4), also known as Prrt1 (Proline-rich transmembrane protein 1) in the regulation of the reserve pool of AMPARs. Proteomic studies indicate that SD4 is a component of AMPAR complexes; however, SD4 is not enriched in the PSD, but instead colocalizes with GluA1-containing AMPARs at non-synaptic sites. Remarkably, tetanus-induced LTP, which is dependent on GluA1, is abolished in acute hippocampal slices from SD4 knockout (KO) while theta-burst stimulation LTP (TBS-LTP), which is independent of GluA1, is not impaired. Furthermore, SD4 KO mice exhibit profound deficits in two independent cognitive assays (Morris water maze, novel object recognition), demonstrating a critical role for SD4 in hippocampal-dependent learning and memory. Moreover, extrasynaptic AMPARs are reduced in SD4 KO compared with wild-type (WT) neurons. Given that reserve pools of extrasynaptic AMPARs are critical for synaptic plasticity, we hypothesize that SD4 maintains such reserve pools of extrasynaptic GluA1-containing AMPARs that are deployed during tetanus-induced LTP. In this collaborative dual-PI application we propose a comprehensive multidisciplinary approach to investigate SD4-dependent regulation of extrasynaptic GluA1-containing AMPARs with molecular, cellular, and electrophysiological methods. In Aim 1 we will define the mechanism by which SD4 maintains extrasynaptic GluA1-containing AMPARs. In Aim 2 we will determine whether synaptic targeting of reserve pools of GluA1- containing AMPARs during plasticity requires SD4. In Aim 3 we will test whether homomeric GluA1-dependent synapse plasticity mechanisms require SD4 ex vivo at multiple ages. The results of these studies will provide molecular insight into fundamental mechanisms that govern establishment and maintenance of the reserve pools of extrasynaptic AMPARs critical for synaptic plasticity and address a major gap in our knowledge.

突触 AMPA 受体 (AMPAR) 含量的活动依赖性变化，称为“突触可塑性”，是一种将信息存储在神经网络中的机制，从而产生更高阶的认知技能例如学习和记忆过程中的长期增强（LTP），一种广泛研究的突触可塑性形式，突触外 AMPAR 是从附近的储备库中招募的，包括细胞上的突触周围区域表面和细胞内区室，然后锚定于突触后密度（PSD）。经过数十年调查的大量证据已经建立了 AMPAR 的机制相比之下，控制 AMPAR 突触靶向的分子机制。鉴于储备库的招募，建立突触外受体的储备库在很大程度上是未知的。突触外 AMPAR 的增加是 LTP 期间发生的突触快速强化的基础，LTP 是分子建立这种储备池的机制对于我们理解突触可塑性和代表了我们知识上的一个重大差距。 SynDIG（突触分化诱导基因）定义了四个基因家族（SynDIG1-4），它们编码大脑在这里，我们将确定 SynDIG4 (SD4)（也称为 Prrt1）的功能。（富含脯氨酸的跨膜蛋白 1）在 AMPAR 储备池的调控中的蛋白质组学研究。表明 SD4 是 AMPAR 复合物的一个组成部分；然而，SD4 并未在 PSD 中富集，而是在 PSD 中富集。值得注意的是，破伤风诱导的 LTP 与含 GluA1 的 AMPAR 共定位。依赖于 GluA1，在 SD4 敲除 (KO) 的急性海马切片中被废除，同时 theta 爆发此外，SD4 KO 小鼠表现出不依赖于 GluA1 的刺激 LTP (TBS-LTP)。两项独立的认知测试（莫里斯水迷宫、新物体识别）存在严重缺陷，证明 SD4 在海马依赖性学习和记忆中发挥关键作用。与野生型 (WT) 神经元相比，SD4 KO 中的 AMPAR 减少。突触外 AMPAR 对突触可塑性至关重要，我们发现 SD4 维持着这样的储备池突触外含有 GluA1 的 AMPAR 在破伤风诱导的 LTP 期间部署。在这个协作双 PI 应用中，我们提出了一种全面的多学科方法来研究 SD4 依赖性突触外含 GluA1 AMPAR 的分子、细胞和在目标 1 中，我们将定义 SD4 维持突触外的机制。在目标 2 中，我们将确定是否针对 GluA1- 储备池进行突触靶向。在可塑性期间含有 AMPAR 需要 SD4。在目标 3 中，我们将测试同聚 GluA1 是否依赖。突触可塑性机制需要SD4在多个年龄段离体。这些研究的结果将提供。对管理储备建立和维护的基本机制的分子洞察突触外 AMPAR 池对突触可塑性至关重要，并解决了我们知识中的一个重大空白。