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

描述（由申请人提供）：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，从而彻底改变了纤毛作为运动细胞器的认知。本研究结合了遗传、生化、分子和细胞生物学的方法，通过研究蛋白质ARL13B来了解纤毛如何在发育中的脊髓中传递信号并指定细胞命运。由于ARL13B在纤毛中的功能，缺乏ARL13B的小鼠在脊髓中存在细胞规格缺陷。Aim 1中提出的实验将从遗传学上确定ARL13B是否在最初指定神经细胞命运的既定信号通路中起作用。Aim 2将定义ARL13B在神经祖细胞中是如何以及何时被需要的，这些神经祖细胞发育为运动神经元和随后的少突胶质细胞。Aim 3的目标是通过定义调节ARL13B定位的功能域和识别相互作用蛋白，将ARL13B在细胞命运规范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特异中的作用提供新的认识。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表现出的不同表型所强调。肥胖、倒位、不孕症、糖尿病、多指畸形、肾功能障碍、学习障碍、癫痫、耳聋、嗅觉缺失和失明都可以在纤毛缺陷患者中看到，这些都被认为是由于纤毛的形成、运动和信号传导能力的失败造成的。通过建立ARL13B在纤毛发生中的作用机制，并将其与ARL13B在信号传导中指定脊髓细胞命运的作用联系起来，本研究将更好地了解运动神经元和少突胶质细胞的发育，从而影响多发性硬化症和脊髓损伤等髓鞘发育异常疾病的治疗。考虑到控制细胞选择的信号通路与相同通路被破坏的人类疾病状态之间的直接联系，这项拟议的工作具有改善人类健康的巨大潜力

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