Nanomechanics of Src signaling in neuronal growth cones

在神经系统的发育和再生过程中，神经元在神经生长锥的引导下发出过程，神经生长锥是一种高度运动的传感结构，也是研究细胞表面、信号传导和细胞骨架蛋白（如肌动蛋白）之间动态相互作用的理想模型系统。虽然在鉴定定向生长锥迁移中所涉及的分子方面已经取得了重大进展，但其潜在的机制还不清楚。特别是，神经元生长和指导中的机械和生化信号之间的关系仍然是一个谜。为了填补这一知识空白，该项目将研究Src酪氨酸激酶，一种关键的信号传导酶，如何调节肌动蛋白的组织和动力学以及粘附介导的生长和活神经元的力的产生。具体来说，这个项目将确定哪些方面的肌动蛋白动力学的调节Src以及力的生产和Src信号之间的关系，在粘附介导的增长。为了实现这一目标，细胞骨架动力学和Src激活的定量荧光成像将与涉及微量移液器和原子力显微镜（AFM）的生物物理方法相结合。这项研究将显著提高对细胞在定向迁移过程中如何整合传感，信号和细胞骨架动力学的理解。该项目涉及高中，本科和研究生在尖端的活细胞成像和生物物理技术的培训。研究结果不仅将传播给科学界，还将通过一个名为“CELLebration”的网站向广大公众传播，该网站展示有关细胞运动的电影、图像和教育材料，并通过在当地学校的演讲和普渡大学的公共宣传活动（春季节和纳米日）向公众传播。总之，通过高质量的数字成像演示，这项工作将提高公众对定量显微镜和生物物理方法的需求的认识，以解决关键的细胞生物学问题。

During development and regeneration of the nervous system, neurons send out processes guided by the neuronal growth cone, a highly motile sensing structure and an excellent model system to study the dynamic interactions between cell surface, signaling, and cytoskeletal proteins such as actin. Although significant progress has been made in identifying the molecules involved in directional growth cone migration, the underlying mechanisms are not well understood. Particularly, the relationship between mechanical and biochemical signaling in neuronal growth and guidance remains a mystery. To fill this knowledge gap, this project will investigate how Src tyrosine kinase, a key signaling enzyme, regulates actin organization and dynamics as well as adhesion-mediated growth and force production of live neurons. Specifically, this project will determine which aspects of actin dynamics are regulated by Src as well as the relationship between force production and Src signaling in adhesion-mediated growth. To reach this goal, quantitative fluorescent imaging of cytoskeletal dynamics and Src activation will be combined with biophysical approaches involving micropipettes and the Atomic Force Microscope (AFM). This research will significantly improve the understanding of how cells integrate sensing, signaling, and cytoskeletal dynamics during directional migration. The project involves training of High School, undergraduate, and graduate students in cutting-edge live cell imaging and biophysical techniques. The results will not only be disseminated to the scientific community, but also to the broad public through a web site called "CELLebration" displaying movies, images, and educational material about cell motility, through presentations at local schools, and public outreach events at Purdue University (Spring Fest and NanoDays). In summary, through high-quality digital imaging presentations, this work will increase the public awareness for the need for quantitative microscopy and biophysical approaches to solve key cell biological problems.