Polycystins and cilia in C. elegans

描述(由申请者提供)：本研究的目的是了解纤毛的形态和功能。秀丽线虫是研究纤毛生物学的有力模式系统。线虫纤毛的形成、维持和功能所需的许多蛋白质与人类肾脏疾病有关，包括常染色体显性遗传性多囊肾病(ADPKD)。ADPKD影响1000人中的1人，通常导致终末期肾脏疾病。在人类中，多囊蛋白-1(PC-1)或多囊蛋白-2(PC-2)纤毛机械感觉复合体的突变导致ADPKD。在线虫中，多囊蛋白LOV-1和PKD-2位于纤毛膜上，是感觉转导所必需的。因此，多囊藻毒素和纤毛之间的联系似乎是古老的。无论是人肾上皮细胞还是蠕虫感觉神经元，多囊蛋白最终都必须定位在纤毛上，才能进行细胞的感觉功能。多囊蛋白和其他纤毛蛋白是如何定位并进入纤毛的，纤毛是一个空间受限的细胞器，目前尚不清楚。在线虫中，有可能确定控制多囊藻毒素在活体动物中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、钙成像和生物化学等方法来了解多囊藻毒素的调节、功能和定位。一个特定的目的是鉴定和表征调控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KLP-6在纤毛蛋白运输和感觉中的作用，以及识别KLP-6货物。第三个目标是确定纤毛发生和多囊藻毒素纤毛定位所需的新基因。这些在易驯化的模式生物体中的研究将为纤毛形成和功能的机制提供基本的见解。

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.