A novel mechanism for synapse localization in the retina

视网膜突触定位的新机制

基本信息

批准号：
10152981
负责人：
Lisa Goodrich
金额：
$ 25.35万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-12-01 至 2022-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10152981
关键词：
Actins Amacrine Cells Back Binding Binding Proteins Binding Sites Biochemical Genetics Biological Assay Bipolar Disorder Brain Cadherins Cell physiology Cells Cellular Assay Complex Cytoskeleton Data Development Drosophila genus Energy Metabolism Extracellular Domain Eye FAT3 gene Family Fatty acid glycerol esters Future Goals Inner Plexiform Layer Interneurons Investigation Location LoxP-flanked allele Mediating Modeling Molecular Mouse Strains Mus Mutant Strains Mice Nature Nervous system structure Neurites Neurodevelopmental Disorder Neurons Neuropil Pathway interactions Pattern Phenotype Photoreceptors Play Process Protein Tyrosine Phosphatase Proteins Retina Retinal Ganglion Cells Role Series Signal Transduction Site Specificity Stains Synapses System Testing Update Vision Work base cell fate specification cell motility conditional knockout experimental study follow-up genetic approach horizontal cell in vivo evaluation innovation migration mouse genetics mutant neural circuit novel outer plexiform layer receptor recruit response retinal damage retinal neuron screening stem cells synaptogenesis vasodilator-stimulated phosphoprotein

项目摘要

PROJECT SUMMARY Neural circuit function depends on the precise organization of diverse types of synapses. In the vertebrate retina, key computations are performed by parallel networks of microcircuits that form highly ordered systems of synapses that are confined to discrete regions of neuropil. For instance, retinal amacrine cells integrate and compute inputs and then communicate this information to retinal ganglion cells via synapses in the inner plexiform layer (IPL). Although we have begun to identify the molecular mechanisms that dictate what type of synapse should form, we still know very little about how synaptic location is controlled. Our long term goal is to define a molecular pathway for synapse localization. The specific objective of this exploratory project is to test the new hypothesis that the atypical cadherin Fat3 determines where synapses will form by harnessing the activity of two known synaptogenic molecules, the WAVE Regulatory Complex (WRC) and the receptor tyrosine phosphatase protein PTPdelta. Data generated during the course of this work will allow us to update our model and develop a more focused investigation of this pathway in the future. Several observations suggest that Fat3 interacts with the WRC and PTP? to control synapse localization in the retina. Fat3 belongs to a family of atypical cadherins with known roles in planar polarity, a signaling system that creates and aligns asymmetries in neighboring cells by creating molecular subdomains (5). The Fat3 intracellular domain harbors multiple binding sites for diverse effectors, including known cytoskeletal regulators and synaptic components, such as the WRC and PTPdelta. Thus, Fat3 is well-suited to respond to signals in neighboring cells and then induce appropriate intracellular responses needed for synapse development. Consistent with this idea, in fat3 mutant mice, retinal amacrine cells show altered patterns of migration and retain extra processes outside of the IPL that go on to form an ectopic plexiform layer (4). Further, by creating and analyzing mice harboring deletions of various regions of the Fat3-ICD, we found that Fat3’s effects on migration and neurite retraction can be separated from its effects on synapse development. Importantly, Fat3-dependent synapse development appears to depend specifically on interactions with the WRC and PTPdelta. The WRC is a well-studied regulator of local changes to the actin cytoskeleton, including at the synapse (12), while PTPdelta is known to be important for synapse development elsewhere in the nervous system (13-15). To follow up on these observations, we will use a combination of biochemical and genetic approaches to characterize physical interactions among Fat3, WRC, and PTP?; test whether retinal synapse development in wild-type and fat3 mutant mice requires WRC function; and determine how Fat3 and PTPdelta influence each other’s distribution and function by examining single and double mutant mouse strains.

项目摘要神经电路功能取决于潜水员突触类型的精确组织。在脊椎动物视网膜中，关键计算是通过微电路的并行网络进行的，这些网络形成了高度有序的系统仅限于神经胶体离散区域的突触。例如，残留的无链氨酸细胞整合，计算输入，然后通过内部突触将此信息传达给残留的神经节细胞丛状层（IPL）。尽管我们已经开始确定决定了哪种类型的分子机制突触应形成，我们仍然对突触位置的控制方式知之甚少。我们的长期目标是定义突触定位的分子途径。该探索项目的具体目标是测试非典型钙粘蛋白FAT3决定突触将在哪里形成的新假设两个已知的突触分子的活性，波调节复合物（WRC）和受体酪氨酸磷酸酶蛋白PTPDELTA。在这项工作过程中生成的数据将使我们能够更新我们的模型和对将来对这一途径进行更集中的调查。几个观察结果表明FAT3与WRC和PTP相互作用？控制突触的定位视网膜。 FAT3属于一个非典型钙粘蛋白家族，在平面极性中具有已知作用，这是一种信号系统，通过产生分子亚域在邻近细胞中创建和对齐不对称（5）。 FAT3细胞内领域具有多个结合位点，以实现潜水员效应，包括已知的细胞骨架调节剂和突触组件，例如WRC和PTPDELTA。那就是FAT3非常适合响应邻近细胞中的信号然后影响突触发展所需的适当细胞内反应。与这个想法一致在FAT3突变小鼠中，残留的无长突细胞显示出改变的迁移模式，并保留了额外的过程继续形成异位丛状层的IPL（4）。此外，通过创建和分析携带的老鼠 FAT3-ICD的各个区域的删除，我们发现FAT3对迁移和神经逆转的影响可以与其对突触发展的影响分开。重要的是，FAT3依赖性突触发展似乎特别取决于与WRC和PTPDELTA的相互作用。 WRC是一个经过良好研究的调节器肌动蛋白细胞骨架的局部变化，包括在突触（12），而PTPDELTA对神经系统其他地方的突触发展（13-15）。为了跟进这些观察，我们将使用生化方法和遗传方法的结合，以表征FAT3，WRC，WRC之间的物理相互作用和PTP？测试野生型和FAT3突变小鼠的视网膜突触发展是否需要WRC功能；并通过检查单个和双突变小鼠菌株。