Polycystins and Cilia in C. elegans

描述(申请人提供)：纤毛是细胞细胞器，对人类发育、器官功能和感觉都很重要。纤毛形成或功能的缺陷会导致毁灭性的人类疾病或纤毛疾病，包括常染色体显性遗传性多囊肾病(ADPKD)。ADPKD影响1/400-1000人，通常导致终末期肾脏疾病。在人类中，多囊蛋白-1或多囊蛋白-2受体-通道复合体的突变导致ADPKD。尽管纤毛在人类健康中具有深远的医学意义，但纤毛是如何在形态和功能上专门化的仍然知之甚少。这项拟议的研究集中于揭示纤毛生物学的基本原理，这在人类研究中是不可能的，在脊椎动物模型系统中也不容易研究。线虫是一种透明的多细胞动物，具有专门的感觉纤毛，能够在体内成像，其简单性和重复性是前所未有的。我们已经开发了工具和试剂来研究多囊藻毒素在线虫中的定位和功能。我们将使用遗传、分子、成像、生化和电生理学方法来解决三个特定的目标。首先，我们将剖析多囊蛋白信号通路。接下来，我们将确定调控多囊蛋白定位的机制的分子细节，重点是磷酸肌醇和微管蛋白翻译后修饰的作用。最后，我们将使用对神经元RNAi超敏的转基因动物来识别调控PKD-2定位的新基因。这种多学科的方法将提供影响多囊蛋白通道组装和运输的分子的全面图景，并将提供关键的洞察一般纤毛受体贩运。因此，这些研究将对ADPKD等人类疾病具有重要意义，纤毛在这些疾病中发挥着重要的核心作用。 公共卫生相关性：常染色体显性遗传性多囊肾病(ADPKD)是最常见的单基因疾病之一，影响1/400-1000人，没有治疗或治愈的方法。包括ADPKD在内的几种人类遗传病有两个共同特征：纤毛定位基因产物和肾囊肿。考虑到在人类中研究纤毛蛋白功能、定位和疾病之间的联系是非常困难的，替代的实验系统是必要的。在线虫中，研究人类疾病基因同源基因在纤毛形成、形态发生和信号转导中的作用是可行的。这项建议旨在了解控制线虫ADPKD基因产物亚细胞转运的分子机制。

DESCRIPTION (provided by applicant): Cilia are cellular organelles that are important for human development, organ function, and sensation. Defects in cilia formation or function results in devastating human diseases or ciliopathies, including autosomal dominant polycystic kidney disease (ADPKD). ADPKD affects 1/400-1000 individuals, often resulting in end- stage renal disease. In humans, mutations in the polycystin-1 or polycystin-2 receptor-channel complex cause ADPKD. Despite the profound medical importance of cilia in human health, how cilia are specialized in form and function remains poorly understood. This proposed research is focused on uncovering fundamental principals of cilia biology not possible in human studies or easily studied in vertebrate model systems. C. elegans is a transparent, multicellular animal with specialized sensory cilia, features that enable in vivo imaging that is unprecedented in its simplicity and reproducibility. We have developed the tools and reagents to study polycystin localization and function in C. elegans. We will employ genetic, molecular, imaging, biochemical, and electrophysiological approaches to address three specific aims. First, we will dissect polycystin signaling pathways. Next, we will determine the molecular details of mechanisms regulating polycystin localization, focusing on the roles of phosphoinositides and tubulin post-translational modifications. Finally, we will identify new genes regulating PKD-2 localization using transgenic animals that are hypersensitive to neuronal RNAi. This multidisciplinary approach will provide a comprehensive picture of the molecules that influence polycystin channel assembly and trafficking, and will provide critical insight to ciliary receptor trafficking in general. Thus these studies will have important implications in human diseases such as ADPKD in which cilia play an important and central role. PUBLIC HEALTH RELEVANCE: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common monogenic diseases, affecting 1/400-1000 individuals, and having no treatment or cure. Several human genetic disorders, including ADPKD, share two common features: ciliary localized gene products and kidney cysts. Given that it is prohibitively difficult in humans to study the connection between ciliary protein function, localization, and disease, alternative experimental systems are necessary. In C. elegans it is feasible to study the roles of human disease gene homologs in cilia formation, morphogenesis, and signaling. This proposal is aimed at understanding the molecular mechanisms controlling the subcellular trafficking of the C. elegans ADPKD gene products.