NEURONAL GROWTH CONE SIGNAL TRANSDUCTION MECHANISMS

神经元生长锥信号转导机制

• 批准号: 2891926
• 负责人: STEPHEN M STRITTMATTER
• 金额: $ 40.71万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-17 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2891926
• 关键词: G protein; biological signal transduction; growth cones; growth factor receptors; laboratory mouse; membrane proteins; molecular cloning; neurogenesis; neurotrophic factors; receptor coupling; spinal ganglion; tissue /cell culture; transfection; yeast two hybrid system

The growth cone at the distal tip of the extending axon is a specialized sensory apparatus which transduces extracellular signals into growth along appropriate pathways to correct synaptic targets. Its proper function is crucial to nervous system development and hence function. This proposal seeks a molecular understanding of the signal transduction mechanisms at the neuronal growth cone. Particular emphasis is focused on the action of collapsin-1, a member of the semaphorin family of proteins recently recognized to inhibit axonal extension and terminal arborization. The essential role of monomeric G proteins of the rho family and of heterotrimeric G proteins in dorsal root ganglion (DRG) growth cone signal transduction will be examined by introducing mutant activated and dominant negative proteins. The hypothesis that GAP-43 augments sensitivity of the growth cone to extracellular signals will be examined in cultured DRG neurons from mice with a targeted deletion mutation in the GAP-43 gene. A recently identified family of neuronal CRMP proteins appear to be required for collapsin-1 inhibition of growth cone function. This project will further define CRMP action by identifying proteins interacting with CRMP, exploring enzymatic activities of CRMP and comparing the properties of different CRMP family members. Neurite outgrowth and collapsin-1 sensitivity of cells overexpressing different forms of CRMP will be examined. A collapsin-alkaline-phosphatase fusion protein will be used to identify collapsin binding proteins which may serve as collapsin receptors in the neuronal growth cone. Once such receptors are identified their interaction with CRMP, GAP-43, and G proteins can be delineated. Together these experiments provide a detailed description of the molecular events which underlie the growth cone responsiveness to extracellular inhibitory signals such as collapsin-1. Knowledge of these pathways provides necessary groundwork for understanding the pathophysiology of human developmental abnormalities of the brain. The same mechanisms are likely to function during adult nervous system injury and improve function in degenerative neurologic diseases.

在延伸轴突的远端的生长锥是一个专门的 将细胞外信号转化为生长的感觉器官 沿着合适的通路来纠正突触靶点。 其适当 功能对神经系统发育和功能至关重要。 这项提议寻求对信号的分子理解 在神经生长锥的转导机制。 特别 重点是集中在一个名为Bisapsin-1的成员的作用上， 脑信号蛋白家族最近被认为抑制轴突生长 延伸和末端树枝化。 rho家族的单体G蛋白和 背根神经节生长锥中异三聚体G蛋白 将通过引入突变体激活的 和显性负性蛋白质。 假设GAP-43 增加生长锥对细胞外信号的敏感性， 在来自具有靶向缺失的小鼠的培养DRG神经元中检查 差距-43基因突变 最近发现的神经元家族 CRMP蛋白质似乎是必需的，用于抑制细胞凋亡。 生长锥功能 本项目将通过以下方式进一步定义CRMP行动： 鉴定与CRMP相互作用的蛋白质，探索酶促 CRMP的活性及不同CRMP的性能比较 家庭成员 神经突起生长与细胞对BMP 1的敏感性 将检查过表达不同形式的CRMP。 一 碱性磷酸酶融合蛋白将用于鉴定 可在细胞中作为白藜芦醇受体的白藜芦醇结合蛋白 神经生长锥 一旦识别出这些受体， 可以描绘与CRMP、GAP-43和G蛋白的相互作用。 这些实验一起提供了对本发明的组合物的详细描述。 这些分子事件是生长锥对 细胞外抑制信号，如胰蛋白酶-1。 了解这些 路径提供了必要的基础， 人类大脑发育异常的病理生理学。 同样的机制可能在成人神经系统中起作用。 退行性神经病系统损伤与功能改善 疾病