Polycystins and cilia in C. elegans

描述（由申请人提供）：本研究的目的是了解纤毛的形成和功能。秀丽隐杆线虫是研究纤毛生物学的一个强有力的模型系统。秀丽隐杆线虫纤毛形成、维持和功能所需的许多蛋白质与人类肾脏疾病有关，包括常染色体显性多囊肾病（ADPKD）。每1000人中就有1人患有ADPKD，通常会导致终末期肾脏疾病。在人类中，多囊素-1 （PC-1）或多囊素-2 （PC-2）纤毛机械感觉复合体的突变可引起ADPKD。在秀丽隐杆线虫中，多囊素LOV-1和PKD-2定位于纤毛膜上，是感觉转导所必需的。因此，多囊毒素和纤毛之间的联系似乎是一个古老的联系。无论是人肾上皮细胞还是蠕虫感觉神经元，多囊毒素最终都必须定位到纤毛上，才能进行细胞的感觉功能。多囊素和其他纤毛蛋白是如何定位并进入纤毛这一受空间限制的细胞器的，目前尚不清楚。在秀丽隐杆线虫中，有可能确定控制多囊蛋白在活体动物纤毛定位和功能的机制。本研究将利用经典遗传学和反向遗传学、分子生物学、转基因线虫、显微镜、电生理学、钙成像和生化等方法来了解多囊毒素的调控、功能和定位。一个特定的目的是确定和表征调节PKD-2/PC-2纤毛蛋白定位和功能的分子机制。第二个目的是研究运动蛋白KLP-6在纤毛蛋白运输和感觉中的作用，以及确定KLP-6的货物。第三个目标是鉴定纤毛发生和多囊素纤毛定位所需的新基因。这些研究在一个可处理的模式生物将提供基本的见解控制纤毛的形成和功能的机制。

DESCRIPTION (provided by applicant): The goal of this research is to understand how cilia form and function. The nematode Caenorhabditis elegans is a powerful model system to study cilia biology. Many proteins that are required for formation, maintenance, and function of cilia in C. elegans are linked to human renal diseases, including autosomal dominant polycystic kidney disease (ADPKD). ADPKD affects 1 in 1000 individuals, often resulting in end-stage renal disease. In humans, mutations in the polycystin-1 (PC-1) or polycystin-2 (PC-2) ciliary mechanosensory complex cause ADPKD. In C. elegans, the polycystins LOV-1 and PKD-2 localize on the ciliary membrane and are required for sensory transduction. Hence, the connection between the polycystins and cilia seems to be an ancient one. The polycystins must ultimately be localized to cilia in order to conduct the sensory function of the cell, whether it is a human renal epithelial cell or a worm sensory neuron. How the polycystins and other ciliary proteins localize and gain access to the cilium, a spatially restricted organelle, is not known. In C. elegans it is possible to identify the mechanisms controlling polycystin ciliary localization and function in living animals. This study will use classical and reverse genetics, molecular biology, transgenic nematodes, microscopy, electrophysiology, calcium imaging, and biochemical methods to understand the regulation, function, and localization of the polycystins. One specific aim is to identify and characterize the molecular mechanisms regulating PKD-2/PC-2 ciliary protein localization and function. A second aim is to examine the role of the kinesin KLP-6 in ciliary protein transport and sensation, as well as identify KLP-6 cargoes. A third aim is to identify new genes required for ciliogenesis and polycystin ciliary localization. These studies in a tractable model organism will provide basic insights into the mechanisms governing cilia formation and function.