Mechanisms of Axonal Pathfinding Controlled by Netrin-1

描述（由申请人提供）：项目摘要：作为一名独立的科学家，我的职业目标是了解轴突伸长和寻路所涉及的细胞和分子过程，并确定这些过程在神经发育和精神健康障碍中的作用。在Samie R. Jaffrey在康奈尔大学威尔医学院，我研究了轴突内mRNA翻译和蛋白质降解的作用。这种训练补充了我在蛋白质生物化学和突触可塑性方面的博士训练。我计划将联合收割机在体外对原代神经元的研究与小鼠遗传学结合起来，研究控制轴突寻路的信号通路。本研究的目的是研究netrin-1信号转导中局部蛋白翻译和降解的作用。我发现PAR复合物是netrin-1信号传导的关键效应物，并且PAR复合物的中心组分编码PAR 3的转录物定位于轴突并响应netrin-1而翻译。根据我的初步数据，我提出了三个目标。首先，我将描述PAR复合物效应子，泛素E3-连接酶Smurfl，在netrin-1介导的轴突伸长和生长锥转动中的作用。其次，我将使用PARS翻译的荧光报告和轴突特异性RNA干扰来解决局部PAR 3翻译在netrin-1信号传导中的作用。对于这些研究，我将开发新的技术来研究生长锥转向，以补充现有的轴突生长研究。第三，本申请描述了转基因小鼠的设计、产生和分析，所述转基因小鼠表现出PAR 3转录物到轴突的条件性定位。这些小鼠将允许在轴突寻路中建立轴突PARS翻译的生理作用。这项研究将大大推进我们对netrin-1信号传导的理解，并将为神经科学的细胞，分子和遗传方法提供培训。相关性：在发育过程中，未成熟大脑中的引导分子引导轴突到达其目标区域，遵循漫长而复杂的路径;这一过程中的干扰导致神经发育障碍，如精神分裂症。这个应用程序试图解释轴突内部的机制，使其朝着或远离导向分子生长。我希望我的研究将具有广泛的相关性，并可能确定治疗或预防神经发育障碍的可能目标。

DESCRIPTION (provided by applicant): Project Summary: My career goal as an independent scientist is to understand the cellular and molecular processes involved in axon elongation and pathfinding and to identify the role of these processes in neurodevelopmental and mental health disorders. During my postdoctoral training in the laboratory of Dr. Samie R. Jaffrey at Weill Medical College of Cornell University, I have studied the role of intra-axonal mRNA translation and protein degradation. This training complements my doctoral training in protein biochemistry and synaptic plasticity. I plan to combine in vitro studies in primary neurons with mouse genetics to study the signaling pathways governing axonal pathfinding. The objective of this research is to examine to role of local protein translation and degradation in netrin-1 signaling. I have found that the PAR complex is a critical effector of netrin-1 signaling, and that the transcript encoding PAR3, a central component of the PAR complex, is localized to axons and translated in response to netrin-1. Based on my preliminary data, I propose three aims. First, I will characterize the role of a PAR complex effector, the ubiquitin E3-ligase Smurfl, in netrin-1-mediated axon elongation and growth cone turning. Second, I will use a fluorescent reporter of PARS translation and axon-specific RNA interference to address the role of local PAR3 translation in netrin-1 signaling. For these studies, I will develop new techniques to study growth cone turning to complement existing ones for the study of axon growth. Third, this application describes the design, generation, and analysis of transgenic mice that exhibit conditional localization of the PAR3 transcript to axons. These mice will allow the physiological role of axonal PARS translation to be established in axonal pathfinding. This research will significantly advance our understanding of netrin-1 signaling, and it will provide training in cellular, molecular, and genetic approaches to neuroscience. Relevance: During development, guidance molecules in the immature brain direct axons to their target areas, following long and complex pathways; disturbances in this process cause neurodevelopmental disorders, such as schizophrenia. This application seeks to explain the mechanisms inside an axon causing it to grow towards or away from guidance molecules. I expect that my studies will have broad relevance and might identify possible targets for the treatment or prevention of neurodevelopmental disorders.