MOLECULAR MECHANISMS OF NEURONAL MIGRATION

本提案中描述的研究旨在了解 胚胎大脑皮层神经元迁移的分子机制 人类致病基因Lis-1的系列功能研究 米勒-迪克无脑畸形。LIS-1基因突变导致神经元停滞 早期胚胎发育中的迁移，并导致脑畸形 以及受影响个人的严重神经障碍。几个 一系列证据表明，LIS-1可能通过 通过蛋白质-蛋白质与未知分子结合 互动。因此，建议对Lis-1基因进行功能研究 产品首次旨在通过两种方式鉴定LIS-1结合蛋白- 杂交筛选，以及通过直接生化共纯化和 滤镜叠加实验。这些实验有望提供 关于引导神经元的分子通路的关键信息 迁移。该提案还旨在研究细胞生物学 通过分析LIS-1的表达、亚细胞分布特征 蛋白质及其潜能的翻译后修饰 与细胞骨架结构的关系。最后，细胞遗传学 还提出了观察LIS-1表型的实验 基因的过度表达、反义抑制和显性负效应 在仅表达Lis-1的细胞系中控制神经发生 正在经历神经元分化的。在完成这些具体任务后 目标，提出的研究将允许更好地理解如何 人脑的发展，并将进一步提供洞察 脑畸形所致疾病的发病机制。

The research described in this proposal is designed to understand the molecular mechanism on embryonic cortical neuronal migration through a series of functional studies on LIS-1, the gene responsible for human Miller-Dieker lissencephaly. Mutations in LIS-1 cause arrest in neuronal migration during early embryogenesis, and result in brain malformation and severe neurological disorders in affected individuals. Several lines of evidence have suggested that LIS-1 may function through associating with yet unidentified molecule by protein-protein interaction. Thus, the proposed functional studies on the LIS-1 gene product are first aimed at identifying LIS-1 binding proteins by two- hybrid screens, as well as by direct biochemical co-purification and filter overlay experiments. These experiments are expected to provide critical information on the molecular pathways that guide neuronal migration. The proposal is also designed to study the cell biological features of LIS-1 by analyzing the expression, subcellular distribution and posttranslational modification of the protein and its potential relation with cytoskeleton structures. Finally, cell genetic experiments are also proposed for observing the phenotype of LIS-1 overexpression, antisense inhibition and dominant negative effect in controlling neurogenesis in a cell line which only expresses LIS-1 when undergoing neuronal differentiation. Upon accomplishing these specific goals, the research proposed will allow better understandings on how human brain develops, and will further provide insight into the pathogenesis of diseases caused by brain malformation.