The role of mouse ARL13B in cell diversification during spinal cord development

描述(申请人提供)：最近的研究表明纤毛在控制分化和细胞生长的信号事件中发挥作用，从而彻底改变了人们对纤毛作为运动细胞器的看法。这一建议结合了遗传、生化、分子和细胞生物学的方法，以便通过研究一种名为Arl13b的蛋白质来了解纤毛如何发出信号并确定发育中的脊髓中的细胞命运。由于Arl13b在纤毛中的作用，Arl13b缺陷小鼠的脊髓细胞规格存在缺陷。AIM 1中提议的实验将从基因上确定Arl13b是否在最初决定神经细胞命运的已建立的信号通路中发挥作用。目标2将定义神经前体细胞如何以及何时需要Arl13b，这些神经前体细胞发育为运动神经元，随后发展为少突胶质细胞。目标3的目的是通过定义调节Arl13b定位的功能结构域和识别相互作用的蛋白质，将Arl13b在细胞命运指定中的功能与其在纤毛中的功能联系起来。综上所述，这些结果将为纤毛蛋白在细胞规格中的作用提供新的理解。纤毛蛋白在基本细胞功能中发挥的基本作用被这些蛋白缺陷患者所表现出的不同的表型谱所强调。肥胖、内翻、不孕不育、糖尿病、多指、肾功能障碍、学习障碍、癫痫、耳聋、嗅觉障碍和失明都出现在纤毛缺陷的患者身上，被认为是纤毛形成、运动和信号能力失败的结果。通过建立Arl13b在纤毛发生中的作用机制，并将其与Arl13b在信号转导中指定脊髓细胞命运的作用联系起来，拟议的工作将提供对运动神经元和少突胶质细胞发育的更好理解，这些发育可能会影响多发性硬化症和脊髓损伤等髓鞘障碍疾病的治疗。考虑到控制细胞选择的信号通路和人类疾病状态之间的直接联系，这项拟议的工作对改善人类健康具有很高的潜力

DESCRIPTION (provided by applicant): Recent studies have revolutionized the perception of cilia as an organelle of motility by showing cilia play roles in signaling events that control differentiation and cell growth. This proposal combines genetic, biochemical, molecular and cell biological approaches in order to understand how cilia signal and specify cell fate in the developing spinal cord by studying a protein, ARL13B. Mice deficient for ARL13B have defects in cell specification in the spinal cord due to a function of ARL13B in cilia. The proposed experiments in Aim 1 will genetically determine if ARL13B acts in the established signaling pathways that initially specify neural cell fate. Aim 2 will define how and when ARL13B is required in the neural progenitor cells that develop as motor neurons and subsequently as oligodendrocytes. The goal of Aim 3 is to relate the function of ARL13B in cell fate specification to its function in cilia by defining the functional domains that regulate ARL13B localization and by identifying interacting proteins. Taken together these results will provide new understanding of the role of cilia proteins in cell specification. The fundamental role ciliary proteins play in basic cellular functions is underscored by the diverse spectrum of phenotypes exhibited by patients with defects in these proteins. Obesity, situs inversus, infertility, diabetes, polydactyly, renal dysfunction, learning disabilities, epilepsy, deafness, anosmia and blindness are all seen in patients with defective cilia and are thought to result from failures in the formation, motility and signaling ability of cilia. By establishing the mechanism through which ARL13B functions in ciliogenesis and connecting it to the role of ARL13B in signaling to specify spinal cord cell fates the proposed work will provide a better understanding of motor neuron and oligodendrocyte development that can impact the treatment of dysmyelinating diseases such as multiple sclerosis as well as spinal cord injury. Given the direct connections between the signaling pathways that govern cell choice and the human disease states in which the same pathways are disrupted, this proposed work has high potential to improve human health