A Model for Nephronophthisis in Caenorhabditis elegans

 描述(申请人提供)：纤毛是细胞细胞器，对人类发育和健康是必不可少的。很早就知道纤毛被组织成结构和功能不同的隔室，称为基底体、过渡区和纤毛轴。肾病相关纤毛病(NPHP-RC)蛋白定位于先前已知的隔室内的亚区，揭示了隐藏的结构复杂性。例如，NPHP2/Inversin定位于睫状干的近端区域，称为Inversin间隔(InvC)，任何超微结构特征都无法识别该区域。尽管纤毛在人类健康和疾病中具有深远的医学意义，但纤毛的这一区域是如何在空间和功能上组织的仍然知之甚少。确定控制纤毛干区划的机制和了解纤毛区域的生理相关性对于确定抗囊性肾脏疾病和其他与纤毛缺陷相关的纤毛疾病的治疗靶点将是重要的。在线虫中，InvC是保守的，这表明在线虫和人类纤毛中建立InvC和纤毛区划的逻辑是相似的。在线虫中，我们发现InvC和微管(MT)双重区基因在模块中发挥功能，调节纤毛发生、MT模式和微管蛋白谷氨化。NPHP-2与过渡区NPHP-RC模块在基因上相互作用，表明InvC和过渡区组件之间存在间隔室间串扰。在这个相互竞争的更新应用程序中，我们使用线虫，一个用于纤毛生物学和人类纤毛疾病的特殊模型，来解决纤毛是如何在空间和功能上组织的问题。首先，我们将定义倒置舱的起源和功能。为此，我们将研究InvC的时间和空间调节；确定InvC是如何建立的，并确定微管蛋白谷氨酸化是否发挥作用；以及确定脱乙酰酶HDAC-6如何拮抗InvC-和MT双重区成分介导的纤毛发生。其次，我们确定了微管蛋白多谷氨酰化调节纤毛稳定性在NPHP-RCS中的作用。我们将检验NPHP-RC过渡区、InvC和双重区成分调节纤毛通路以及微管蛋白谷氨酰胺酶和脱谷氨酸酶定位的假设。我们将确定微管蛋白多谷氨酸化如何调节基于纤毛运动的运输和MT超微结构。我们将在微管蛋白脱谷氨酰胺酶突变体CCPP-1中鉴定纤毛变性的抑制因子。这项研究将解决与医学相关的问题，即纤毛如何在结构和功能上组织在健康和 并将提供对纤毛区域化和微管蛋白翻译后修饰的分子、机制和功能的基本见解。这些研究对囊性肾脏疾病的研究具有直接的意义，因为我们工作中探索的许多基因和途径与纤毛疾病有关。

 DESCRIPTION (provided by applicant): Cilia are cellular organelles that are essential for human development and health. It has long been known that cilia are organized into structurally and functionally distinct compartments known as the basal body, the transition zone, and the cilia shaft. Nephronophthisis-related ciliopathy (NPHP-RC) proteins localize to subregions within the previously known compartments, revealing a hidden structural complexity. For example, NPHP2/Inversin localizes to a proximal region of the ciliary shaft called the Inversin Compartment (InvC) that is not identifiable by any ultrastructural features. Despite the profound medical importance of cilia in human health and disease, how this region of the cilium is spatially and functionally organized remains poorly understood. Identifying mechanisms controlling cilia shaft compartmentalization and understanding the physiological relevance of ciliary territories will be important in identifying therapeutic targets to combat cystic kidney diseases and other ciliopathies associated with ciliary defects. The InvC is conserved in the nematode C. elegans, suggesting that the logic underlying the establishment of the InvC and ciliary compartmentalization is similar in worm and human cilia. In C. elegans, we found that the InvC and microtubule (MT) doublet region genes function in modules to regulate ciliogenesis, MT patterning, and tubulin glutamylation. nphp-2 genetically interacts with the transition zone NPHP-RC modules, indicating inter-compartmental crosstalk between the InvC and transition zone components. In this competing renewal application, we use C. elegans, an exceptional model for ciliary biology and human ciliopathies, to address the question of how the cilium is spatially and functional organized. First, we will define the origin and function of the Inversin compartment. To this end, we will study InvC temporal and spatial regulation; ascertain how the InvC is established and determine whether tubulin glutamylation plays a role; and determine how the deacetylase HDAC-6 antagonizes InvC- and MT doublet region component-mediated ciliogenesis. Second, we determine how ciliary stability regulated by tubulin polyglutamylation may be involved in NPHP-RCs. We will test the hypothesis that NPHP- RC transition zone, InvC, and doublet region components regulate ciliary access and localization of tubulin glutamylases and deglutamylases. We will determine how tubulin polyglutamylation regulates ciliary motor- based transport and MT ultrastructure. We will identify suppressors of ciliary degeneration in the tubulin deglutamylase mutant ccpp-1. This research will address the medically relevant question of how cilia are structurally and functionally organized in healthy and diseased states, and will provide fundamental insight to the molecules, mechanisms, and functions of ciliary compartmentalization and tubulin post-translational modifications. These studies have direct implications for cystic kidney disease research because many of the genes and pathways explored in our work are associated with ciliopathies.