Genetic analysis of the adenylate forming domain protein DIP-2 in C. elegans neuronal development

神经元表现出各种各样的形态，对连接和功能都有贡献。神经元形态是在发育的关键时期建立起来的，此时细胞骨架结构和重排调节轴突和树突的规范、神经元连接的连接以及树突束的活动依赖和独立的形成。发育后，神经元的寿命非常长，虽然被证明能够促进树突结构的可塑性重塑，但被认为在成年后保持相对稳定的形态。维持神经元形态的分子机制仍然知之甚少。 我的实验室感兴趣的是，如何使用线虫这种微小蠕虫在解剖上简单的神经系统作为模型系统来建立和维持神经元的形态。我们最近发现，DIP-2(Disco Interaction Protein-2，DIP2)的蠕虫同源基因DIP-2的突变在多种类型的神经元中显示出强烈的神经元形态缺陷，表明DIP-2在神经系统的发育和维持中发挥着中心作用。DIP2蛋白属于高度保守但知之甚少的腺苷形成结构域蛋白家族。我们的目标是了解腺苷形成结构域蛋白DIP-2如何维持神经元的形态。首先，我们建议采用无偏见的基因/蛋白质发现方法来识别显示DIP-2样神经元形态缺陷或异常DIP-2蛋白定位的基因突变(目标1A)和神经元中DIP-2蛋白复合体的新成分(目标1B)，第二，鉴定在DIP-2介导的神经元维持中直接起作用的候选基因/蛋白质(目标2)。这些目标的成功完成应该会导致对神经元如何在正常衰老过程中保持其形态的基本洞察。

Neurons exhibit a diverse array of morphologies that contribute to both connectivity and function. Neuronal morphology is established during critical developmental periods when cytoskeletal structures and rearrangements mediate the specification of axon and dendritic processes, wiring of neuronal connections and the activity-dependent and independent elaboration of dendritic arbours. Post-developmentally, neurons are very long lived and, while shown to be capable of plasticity-promoting remodeling of dendritic structures, are thought to maintain relatively stable morphologies over adulthood. The molecular mechanisms that maintain neuronal morphology remain poorly understood. My lab is interested in how neuronal morphology is established and maintained using the anatomically simple nervous system of C. elegans, a microscopic worm, as a model system. We have recently found that mutations in dip-2, the worm orthologue of Disco Interacting Protein-2 (DIP2), display strong neuronal morphology defects in multiple types of neurons suggesting a central role in both nervous system development and maintenance. DIP2 proteins belong to a highly conserved but poorly understood family of adenylate forming domain proteins. Our objective with this Discovery Grant is to understand how the adenylate forming domain protein DIP-2 acts to maintain neuronal morphology. First, we propose to undertake unbiased gene/protein discovery' approaches to identify mutations in genes that display dip-2-like neuronal morphology defects or aberrant DIP-2 protein localization (Aim 1A) and new components of DIP-2 protein complexes in neurons (Aim 1B) and second, characterize the resulting genes/protein candidates for direct roles in DIP-2 mediated neuronal maintenance (Aim 2). Successful completion of these aims should lead to fundamental insight into how neurons maintain their morphology during the normal aging process.