Molecular mechanisms of axon guidance receptor regulation and signaling

轴突引导受体调节和信号转导的分子机制

• 批准号: 10045309
• 负责人: Greg J. Bashaw
• 金额: $ 2.8万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-12-15 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10045309
• 关键词: Address; Area; Axon; Biochemical; Biological; Cell Nucleus; Cells; Collaborations; Cues; Dendrites; Development; Disease; Drosophila genus; Embryonic Nervous System; Ensure; Family; Fluorescence-Activated Cell Sorting; Fos-Related Antigens; Genetic; Genetic Transcription; Human; Injury; Knowledge; Link; Malignant Neoplasms; Methods; Modeling; Molecular; Molecular Biology; Molecular Genetics; Morphogenesis; Motor Neurons; Nerve Regeneration; Nervous system structure; Neurons; Output; Pathogenesis; Pathway interactions; Play; Property; Proteins; Receptor Activation; Receptor Signaling; Regulation; Reporter; Research; Resolution; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Specific qualifier value; Specificity; System; Testing; Therapeutic; Transcript; Transcription Coactivator; axon growth; axon guidance; developmental disease; genetic manipulation; in vitro activity; in vivo; insight; mutant; nervous system development; nervous system disorder; neural circuit; neuron development; premature; programs; receptor; relating to nervous system; repaired; response; screening; transcription factor

PROJECT SUMMARY Determining how neurons are correctly specified and assembled into functional circuits will provide insight into developmental disorders of the nervous system and may suggest therapeutic approaches to promote nerve regeneration. Slit and Netrin, and their Robo and Fra/DCC receptors, are evolutionary conserved families of signaling molecules that play important roles in regulating neuronal development; however, the understanding of how these receptors are regulated and how they signal to direct axon growth and guidance is incomplete. These are important questions because perturbations of these signaling pathways are implicated in diseases of nervous system development. Slits, Netrins and their receptors also play essential roles outside of the nervous system and disruptions of these pathways are associated with several kinds of cancer. Our research program focuses on three broad areas related to the roles and regulation of these molecules in neuronal development using the genetically tractable Drosophila embryonic nervous system as a model. First, we are working to define functional and molecular links between conserved transcriptional regulators that impart neuronal subtype identity and the Robo and Fra/DCC receptors that coordinate axon guidance and dendrite morphogenesis in response to Slit and Netrin. Here, we will use genetic and molecular screening approaches, including Fluorescence Activated Cell sorting (FACs) of defined subsets of motor neurons, together with transcript profiling in wild type and mutant backgrounds, to systematically identify additional effectors of these transcriptional programs. Second, we are characterizing a newly discovered mechanism through which the Frazzled/DCC receptor intracellular domain (ICD) itself can act in the nucleus as a transcriptional activator to regulate commissureless expression to ensure that commissural axons avoid premature responses to midline repellent Slit. Here, we will use genetic and molecular approaches to identify factors that cooperate with the Fra ICD to regulate transcription and transcript profiling methods to identify additional targets of the Fra ICD. In addition, we will explore whether signaling from the nucleus is a common property of axon guidance receptors and through collaboration we will test if this is a conserved property of guidance receptors. Third, we are determining the molecular mechanisms underlying Robo and Fra/DCC receptor signaling during axon guidance using molecular, genetic, biochemical and cell biological approaches. Specifically, we use in vivo genetic manipulation, together with fluorescently tagged receptors and reporters of signaling molecule activity in vitro, to define the cell biological outputs of receptor activation with sub-cellular resolution. Our research program will define new concepts in the molecular biology of axon guidance, inform studies of related proteins in mammalian systems and will likely enhance our understanding of neural developmental disorders.

项目摘要 确定如何正确指定神经元并组装成功能电路 深入了解神经系统的发育障碍，并可能提出治疗方法 促进神经再生。缝隙和网络以及它们的机器人和FRA/DCC受体是进化的 信号分子的保守家族在调节神经元发育中起重要作用； 但是，对这些受体的调节方式以及它们如何发出指向轴突的理解 增长和指导是不完整的。这些是重要的问题，因为这些问题的扰动 信号通路与神经系统发育的疾病有关。缝隙，网络及其 受体在神经系统之外还起着重要作用，这些途径的中断是 与几种癌症有关。我们的研究计划侧重于与 这些分子在神经元发育中的作用和调节，使用遗传学处理 果蝇胚胎神经系统作为模型。首先，我们正在努力定义功能和 赋予神经元亚型身份的保守转录调节剂之间的分子联系 在协调轴突引导和树突形态发生的机器人和FRA/DCC受体中 对缝隙和网络的反应。在这里，我们将使用遗传和分子筛选方法，包括 运动神经元定义的子集的荧光激活细胞分选（FACS）以及 野生型和突变背景的笔录分析，以系统地识别 这些转录程序。其次，我们正在描述一种新发现的机制 毛茸茸的/DCC受体细胞内结构域（ICD）本身可以在细胞核中作用 转录激活器调节无连锁表达，以确保避免轴突 对中线驱虫缝隙的过早响应。在这里，我们将使用遗传和分子方法 确定与FRA ICD合作以调节转录和转录分析方法的因素 确定FRA ICD的其他目标。此外，我们将探讨是否发出信号 核是轴突引导受体的常见特性，通过协作，我们将测试是否 是指导受体的保守特性。第三，我们确定分子机制 在轴突引导过程中使用分子，遗传，基础机器人和FRA/DCC受体信号传导 生化和细胞生物学方法。具体而言，我们一起使用体内遗传操作 荧光标记的受体和信号分子活性的记者，以定义细胞 通过亚细胞分辨率激活受体激活的生物输出。我们的研究计划将定义 轴突指导分子生物学中的新概念，为相关蛋白的研究提供了有关相关蛋白的研究 哺乳动物系统，可能会增强我们对神经发育障碍的理解。