MOLECULAR STUDIES OF PRIMARY CILIUM BIOGENESIS

原代纤毛生物发生的分子研究

• 批准号: 8450115
• 负责人: Maxence V Nachury
• 金额: $ 29.81万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8450115
• 关键词: Bardet-Biedl Syndrome; Binding; Binding Proteins; Biochemical; Biological Assay; Cell Polarity; Cell model; Cell surface; Cells; Cilia; Clathrin; Clathrin Adaptors; Clinical; Coat Protein Complex I; Complex; Cystic kidney; Cytoplasmic Tail; Data; Defect; Disease; Docking; Erinaceidae; Etiology; Functional disorder; Goals; Growth; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; Hereditary Disease; Hydrolysis; Inborn Genetic Diseases; Individual; Integral Membrane Protein; Lead; Liver diseases; Mediating; Membrane; Membrane Proteins; Modality; Modeling; Molecular; Names; Nucleotides; Obesity; Organ; Output; Polycystic Kidney Diseases; Property; Protein translocation; Proteins; Reaction; Receptor Signaling; Recruitment Activity; Research; Research Proposals; Retinal Degeneration; Role; Signal Pathway; Signal Transduction; Sorting - Cell Movement; Surface; Symptoms; Testing; Time; Variant; Vesicle; Weight; base; cilium biogenesis; insight; polymerization; public health relevance; reconstitution; research study; skeletal abnormality; therapeutic development; trafficking

DESCRIPTION (provided by applicant): The primary cilium, a "signaling antenna" projecting at the surface of the cell, is required for the transduction of Hedgehog and planar cell polarity signals and concentrates many signaling receptors on its surface. Furthermore, ciliary dysfunction leads to obesity, retinal degeneration and kidney cysts in the inherited disorder Bardet-Biedl Syndrome (BBS). Yet, the mechanisms of signaling receptor trafficking to the ciliary membrane are not understood. We recently discovered a stable complex of seven BBS proteins, that we named the BBSome and have implicated in vesicular trafficking to the cilium based on its functional interaction with Rab8, a GTPase with a well-established trafficking function whose manipulations directly impact cilium growth. Here, we advance the hypothesis that the BBSome sorts specific transmembrane proteins to the primary cilium. In this research proposal, we will dissect BBSome function within the context of vesicular transport to the cilium through the following aims: 1- Identify the transmembrane proteins transported by the BBSome towards the cilium. Known ciliary transmembrane proteins will be tested for a BBSome requirement in their trafficking to cilia and we will establish a time-resolved trafficking assay to identify the donor compartment from which the BBSome selects its cargoes. 2- Dissect the mechanisms of BBSome targeting to cilia. We will assay the function of BBSome-binding proteins in mediating the recruitment of the BBSome to cilia. 3- Characterize the functional interplay between the BBSome and Rab8. In preliminary studies, we have found that the BBSome interacts with Rabin8, the GDP/GTP exchange factor for Rab. Here, we will seek to understand how the BBSome modulates the activity and localization of Rabin8 to enable Rab8 entry into the cilium. In conclusion, our model for BBSome function has significant implications for the etiology of Bardet-Biedl syndrome: in a model where the BBSome targets specific signaling receptors to the cilium, each individual symptom of BBS results from the disruption of a specific ciliary signaling pathway.

描述（由申请人提供）：初级纤毛是突出于细胞表面的“信号天线”，是刺猬和平面细胞极性信号转导所必需的，并且在其表面上集中了许多信号接收器。此外，纤毛功能障碍会导致肥胖、视网膜变性和遗传性疾病巴代-比德尔综合征 (BBS) 中的肾囊肿。然而，信号受体运输到睫状膜的机制尚不清楚。我们最近发现了一种由七种 BBS 蛋白组成的稳定复合物，我们将其命名为 BBSome，并且基于其与 Rab8 的功能相互作用，该复合物与囊泡向纤毛的运输有关。Rab8 是一种具有完善的运输功能的 GTP 酶，其操作直接影响纤毛的生长。在这里，我们提出了这样的假设：BBSome 将特定的跨膜蛋白分类到初级纤毛。在本研究计划中，我们将通过以下目标在囊泡运输至纤毛的背景下剖析 BBSome 的功能： 1- 识别 BBSome 向纤毛运输的跨膜蛋白。将测试已知的纤毛跨膜蛋白在运输到纤毛时是否符合 BBSome 的要求，我们将建立时间分辨运输测定法来识别 BBSome 选择其货物的供体区室。 2-剖析 BBSome 针对纤毛的机制。我们将测定 BBSome 结合蛋白在介导 BBSome 募集到纤毛中的功能。 3- 描述 BBSome 和 Rab8 之间功能相互作用的特征。在初步研究中，我们发现 BBSome 与 Rabin8（Rab 的 GDP/GTP 交换因子）相互作用。在这里，我们将寻求了解 BBSome 如何调节 Rabin8 的活性和定位以使 Rab8 进入纤毛。总之，我们的 BBSome 功能模型对 Bardet-Biedl 综合征的病因学具有重要意义：在 BBSome 将特定纤毛信号传导受体作为目标的模型中，BBS 的每个单独症状都是由特定纤毛信号传导途径的破坏引起的。