Genetic Regulation of Neuronal Migration

描述(申请人提供)：最近，人类和小鼠的遗传学方法促进了我们对控制大脑发育的分子机制的理解，这些方法已经确定了新皮质发育和神经元迁移所需的几个基因和蛋白质产物。基于对小鼠模型的遗传、生化和细胞生物学研究，这些基因和蛋白产物中的许多被放入三个主要的功能通路：RELN通路、CDK5/p35通路和Lis1通路。这个项目最近的研究已经确定了这三个途径之间的一些重要的串扰。然而，在我们的理解中有几个关键的差距。首先，目前尚不清楚这些途径和相互作用是否只调控神经元迁移或参与大脑发育的其他过程，如神经发生和生存。其次，这些不同的组件和信号通路相互连接的方式和程度尚不清楚。最后，OCX与神经元迁移的三条主要途径的关系尚不清楚。在神经元迁移过程中，确定基因产物及其信号通路的整合对于更全面地理解控制新皮质发育的分子复杂性是至关重要的。因此，我们建议通过以下特定的目的来研究这些通路的整合：目的1.通过检测在体内的神经发生、神经元迁移、细胞存活和成年神经元功能过程中的剂量依赖效应来验证这一假设，即在脑发育过程中和在成人中具有几个重要的功能。根据我们已发表的和初步的数据，我们预测，在大脑发育的所有阶段，甚至在有丝分裂后的成人大脑中，Lis1都是关键的，尽管在非神经元体组织中不是。目的2通过BAG转基因产生特异性CDK5磷酸化位点突变体，验证CDK5/p35对Nudel的磷酸化及其与14-3-3 epsilon结合对体内神经元发育和迁移起关键作用的假说。目的3验证OCX是Lis1通路的一部分的假设。根据我们的初步数据，我们预测OCX在LIS1中起着调节动力蛋白运动功能的作用，并且通过CDK5/p35的磷酸化来调节OCX的活性可能类似于Nudel的调节。

DESCRIPTION (provided by applicant): Recently our understanding of the molecular mechanisms governing the development of the brain has been facilitated by genetic approaches in human and mouse that have identified several genes and protein products required for neocortical development and neuronal migration. Many of these genes and protein products have been placed into three major functional pathways, based on genetic, biochemical and cell biological studies in mouse models: the RELN pathway, the Cdk5/p35 pathway and the LIS1 pathway. Recent studies from this program project have identified some important cross-talk between these three pathways. However, there are several critical gaps in our understanding. First, it is unknown if these pathways and interactions regulate exclusively neuronal migration or other processes involved in brain development such as neurogenesis and survival. Second, the manner and degree in which these various components and signaling pathways are interconnected are not known. Finally, the relationships of OCX to the three major pathways of neuronal migration are unknown. It is critical to determine the integration of the gene products and their signaling pathways during neuronal migration for a more comprehensive understanding of the molecular intricacies that govern neocortical development. Therefore, we propose to investigate the integration of these pathways by the following Specific Aims: Aim 1. Test the hypothesis that LIS1 has several important functions during brain development and in the adult by examining the dosage dependent effects of LIS1 during neurogenesis, neuronal migration, cell survival and adult neuronal function in vivo. Based on our published and preliminary data, we predict that LIS1 is critical for processes at all stages of brain development, and even in the postmitotic adult brain, although not in non-neuronal somatic tissues. Aim 2 Test the hypothesis that the phosphorylation of NUDEL by Cdk5/p35 and binding to 14-3-3epsilon are critical for neuronal development and migration in vivo by producing specific Cdk5 phosphorylation site mutants in mice by BAG transgenesis. Aim 3 Test the hypothesis that OCX is part of the LIS1 pathway. Based on our preliminary data, we predict that with LIS1, OCX plays a role in the regulation of dynein motor function, and that regulation of OCX activity via phosphorylation by Cdk5/p35 may be analogous to NUDEL regulation.