Spatiotemporal Dynamics of RhoA Activation in Growth Cone Motility

生长锥运动中 RhoA 激活的时空动态

• 批准号: 7485880
• 负责人: Eric A Vitriol
• 金额: $ 2.67万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-15 至 2011-07-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7485880
• 关键词: Asses; Axon; Biological Models; Biosensor; Cells; Conflict (Psychology); Cultured Cells; Cytoskeleton; Data; Development; Disease; Event; Failure; Growth Cones; Heterogeneity; Kinetics; Label; Lead; Life; Link; Location; Maps; Microscopy; Microtubules; Monitor; Monomeric GTP-Binding Proteins; Natural regeneration; Nerve; Nerve Regeneration; Nervous System Trauma; Neuroblastoma; Neurons; Pattern; Public Health; Regulation; Relative (related person); Research Institute; Resolution; Signal Pathway; Signal Transduction; Spatial Distribution; Time; axon growth; axon guidance; cell behavior; cell motility; cell type; image processing; injured; intracellular protein transport; novel; protein localization location; spatiotemporal; submicron; tool

DESCRIPTION (provided by applicant): The small GTPase RhoA causes growth cone collapse and halts axon growth, thereby inhibiting regeneration of injured nerves. In contrast, RhoA has also been shown to promote growth cone advance under specific circumstances, and is important for guidance in growth cone motility. The broad objective of this proposal is to deduce how, through precise control of RhoA activation kinetics and localization, this protein can stimulate opposite cell behaviors. To resolve this conflict, we will utilize a biosensor to directly visualize the activation of RhoA in growing and retracting neurons, and manipulate microtubules to probe underlying mechanisms in RhoA signaling. Specific Aim 1 will determine the spatiotemporal dynamics of RhoA activation in growth cones during both extension and collapse, using novel image processing tools to generate a dynamic map of RhoA activation with subsecond and submicron resolution. The microtubule cytoskeleton is a master regulator of growth cone motility and guidance; it is both a major downstream target and upstream activator of RhoA. Specific Aim 2 will determine the relationship between RhoA activation and microtubule distribution and dynamics in growth cones. PUBLIC HEALTH RELEVANCE: In addition to nervous system regeneration failure, there are a host of severe and debilitating developmental diseases in which axon growth fails. Understanding the basic mechanism behind growth cone motility and axon extension can lead to the development of new treatments for nervous system injury and disease.

描述（由申请人提供）：小型 GTP 酶 RhoA 导致生长锥塌陷并停止轴突生长，从而抑制受损神经的再生。相比之下，RhoA 也被证明可以在特定情况下促进生长锥前进，并且对于指导生长锥运动很重要。该提案的主要目标是推断通过精确控制 RhoA 激活动力学和定位，该蛋白质如何刺激相反的细胞行为。为了解决这一冲突，我们将利用生物传感器直接可视化 RhoA 在神经元生长和收缩过程中的激活，并操纵微管来探测 RhoA 信号传导的潜在机制。具体目标 1 将使用新颖的图像处理工具生成亚秒和亚微米分辨率的 RhoA 激活动态图，确定生长锥在延伸和塌缩过程中 RhoA 激活的时空动态。微管细胞骨架是生长锥运动和引导的主要调节器；它既是 RhoA 的主要下游靶点，又是上游激活剂。具体目标 2 将确定 RhoA 激活与生长锥中微管分布和动力学之间的关系。 公众健康相关性：除了神经系统再生失败之外，还有许多严重且使人衰弱的发育疾病，其中轴突生长失败。了解生长锥运动和轴突延伸背后的基本机制可以促进神经系统损伤和疾病新疗法的开发。