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.

项目概要神经回路功能取决于脊椎动物视网膜中不同类型突触的精确组织。关键计算由微电路的并行网络执行，这些微电路形成高度有序的系统仅限于离散的神经纤维的突触例如，视网膜无长突细胞整合并形成。计算输入，然后通过内部突触将此信息传递给视网膜神经节细胞尽管我们已经开始确定决定什么类型的分子机制。突触应该形成，但我们对突触位置是如何控制的仍然知之甚少，我们的长期目标是。定义突触定位的分子途径该探索性项目的具体目标是测试。新的假设是，非典型钙粘蛋白 Fat3 通过利用两种已知的突触分子的活性，即 WAVE 调节复合体 (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未来对该途径进行更有针对性的研究。一些观察表明 Fat3 与 WRC 和 PTP 相互作用来控制突触定位？ Fat3 属于非典型钙粘蛋白家族，在平面极性（一种信号系统）中具有已知的作用。通过创建 Fat3 细胞内分子子域来创建和对齐相邻细胞的不对称性 (5)。结构域具有多种效应子的结合位点，包括已知的细胞骨架调节因子和突触因此，Fat3 非常适合响应相邻细胞中的信号。然后诱导突触发育所需的适当的细胞内反应，在 fat3 突变小鼠中，视网膜无长突细胞显示出改变的迁移模式并保留了外部的额外过程进一步，通过创建和分析小鼠来形成异位丛状层 (4)。通过删除 Fat3-ICD 的各个区域，我们发现 Fat3 对迁移和神经突回缩的影响可以重要的是，Fat3 依赖的突触发育与其对突触发育的影响分开。似乎特别依赖于与 WRC 和 PTPdelta 的相互作用 WRC 是一个经过充分研究的调节器。肌动蛋白细胞骨架的局部变化，包括突触处的变化 (12)，而已知 PTPdelta 对肌动蛋白细胞骨架的局部变化很重要为了跟进这些观察结果，我们将使用神经系统其他地方的突触发育。结合生化和遗传学方法来表征 Fat3、WRC、和 PTP？；测试野生型和 fat3 突变小鼠的视网膜突触发育是否需要 WRC 功能；并通过检查单个和 PTPdelta 来确定 Fat3 和 PTPdelta 如何影响彼此的分布和功能双突变小鼠品系。