Cilia Assembly and Transport in the Vertebrate Retina

脊椎动物视网膜中纤毛的组装和运输

基本信息

批准号：
8187542
负责人：
Brian D Perkins
金额：
$ 27.43万
依托单位：
TEXAS A&M UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-08-01 至 2012-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8187542
关键词：
Address Adult Affect Alleles Anatomy Animal Model Apical Architecture Bardet-Biedl Syndrome Behavioral Binding Biological Models Blindness Body Regions Candidate Disease Gene Cell Polarity Cell Survival Cells Cilia Clinical Complex Defect Development Disease Docking Dominant-Negative Mutation Dsh protein Dynein ATPase Electron Microscopy Electrons Embryo Functional disorder Gene Components Gene Expression Gene Mutation Genes Genetic Goals Golgi Apparatus Human Individual Joubert syndrome Kidney Diseases LIS1 protein Lead Link Maintenance Mental Retardation Microscopic Microtubules Modeling Molecular Monomeric GTP-Binding Proteins Motor Movement Mutation Organelles Pathway interactions Pattern Phenotype Photoreceptors Play Polydactyly Population Positioning Attribute Process Proteins Reagent Regulation Retina Retinal Retinal Degeneration Retinal Diseases Retinal Dystrophy Role Side Signal Pathway Signal Transduction Site Situs Inversus Stereotyping Structure Surface System TNFRSF5 gene Techniques Testing Tissues Transgenic Organisms Travel Vertebrate Photoreceptors Vertebrates Vision Zebrafish base body position cell motility ciliopathy cilium biogenesis dynactin hereditary blindness kinetosome light microscopy loss of function mutant novel null mutation particle photoreceptor degeneration prevent protein transport retinal damage therapy development tool trafficking

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the molecular basis of cilia formation and maintenance in vertebrate photoreceptor cells and how mutations in cilia genes cause retinal degeneration. In vertebrates, the assembly and maintenance of photoreceptor outer segments begins with the formation of a connecting cilium. The connecting cilium contains a microtubule-based axoneme that is anchored to the apical inner segment by a basal body. Cilia formation begins with the docking of basal bodies at the apical surface of the inner segment. Extension and maintenance of the ciliary axoneme requires the bi-directional motility process of Intraflagellar Transport (IFT) to carry proteins from the photoreceptor inner segment and outer segment. Genetic mutations disrupting the assembly, structure, or function of basal bodies and/or cilia result in a spectrum of diseases known as ciliopathies. These multisyndromic disorders often present with retinal degeneration, kidney disease, mental retardation, and polydactyly. In the current application, we will utilize loss-of-function strategies in zebrafish to investigate the mechanisms controlling basal body localization and determine how mutations in cep290 and arl13b, which are causative for Joubert Syndrome and other ciliopathies, lead to retinal degeneration. In Specific Aim 1, we will examine zebrafish carrying null mutations in cep290 and arl13b for retinal phenotypes. We will also test cep290 and arl13b for functional interactions with Bardet-Biedl Syndrome (BBS) genes, IFT genes, and components of the Planar Cell Polarity (PCP) pathway. These interactions will identify potential second-site modifiers that enhance expression of photoreceptor phenotypes. In Specific Aim 2, we will test the hypothesis that the dynactin complex regulates cytoplasmic dynein motors during basal body docking and ciliogenesis by examining zebrafish mutants in the p150 and p50 subunits of dynactin. In Specific Aim 3, we will directly test the hypothesis that the PCP pathway functions in photoreceptors to control the polarized positioning of basal bodies and that defects in PCP signaling can contribute to photoreceptor degeneration. Our preliminary evidence indicates that basal bodies indeed show a highly polarized arrangement within the adult zebrafish retina. We will determine if this patterning exists during development. We will then express dominant-negative forms the core PCP protein Disheveled (Dvl) in photoreceptors and determine if this leads to retinal degeneration. The results of these studies will allow us to study genes that play critical roles during both cilia assembly and maintenance and will identify novel gene candidates for hereditary blindness so that therapies can be developed to prevent vision loss. PUBLIC HEALTH RELEVANCE: In the vertebrate retina, photoreceptor survival depends on the proper formation and maintenance of the connecting cilium and outer segment. The cilium is a complex organelle that is of great clinical importance because dysfunction in cilia assembly or function can lead to retinal degeneration, kidney disorders, mental retardation, situs inversus, polydactyly, and other conditions. An understanding of the mechanisms that control the formation, positioning, and structural integrity of cilia will lead to the development of treatments for ciliary diseases.

描述（由申请人提供）：该项目的长期目标是了解脊椎动物感光细胞中纤毛形成和维持的分子基础，以及纤毛基因中的突变如何引起视网膜变性。在脊椎动物中，光感受器外部段的组装和维护始于形成连接纤毛。连接的纤毛包含一个基于微管的轴突，该轴突由基底体固定在顶端内部段。纤毛形成始于内部段顶部表面基底体的对接。睫状轴突的延伸和维护需要flagellar转运（IFT）的双向运动过程，以携带感光体内部段和外部段的蛋白质。基础体和/或纤毛的组装，结构或功能的基因突变导致多种疾病被称为纤毛病。这些多种疾病通常出现视网膜变性，肾脏疾病，智力低下和多性疾病。在当前的应用中，我们将利用斑马鱼中的功能丧失策略来研究控制基础身体定位的机制，并确定CEP290和ARL13B中的突变是如何导致乔伯特综合征和其他纤毛疾病的原因的，导致了视网膜变性。在特定的目标1中，我们将检查斑马鱼在CEP290和ARL13B中的视网膜表型中携带无效突变。我们还将测试CEP290和ARL13B与Bardet-Biedl综合征（BBS）基因，IFT基因以及平面细胞极性（PCP）途径的成分的功能相互作用。这些相互作用将确定潜在的第二位修饰符，以增强光感受器表型的表达。在特定的目标2中，我们将测试以下假设：在基础身体对接和纤毛发生过程中，dynactin复合物调节细胞质动力蛋白电动机，通过检查dynactin的P150和P50亚基中的斑马鱼突变体。在特定的目标3中，我们将直接检验以下假设：PCP途径在光感受器中起作用以控制基础体的极化定位，并且PCP信号传导中的缺陷可能有助于感光细胞的变性。我们的初步证据表明，基底体确实显示了成年斑马鱼视网膜中高度极化的排列。我们将确定在开发过程中是否存在这种图案。然后，我们将在感光体中表达显性阴性的核心PCP蛋白质染色（DVL），并确定这是否导致视网膜变性。这些研究的结果将使我们能够研究在纤毛组装和维护过程中起着关键作用的基因，并将确定遗传性失明的新型基因候选者，从而可以开发出疗法以防止视力丧失。公共卫生相关性：在脊椎动物视网膜中，感光器的存活取决于连接纤毛和外部细分市场的适当形成和维护。纤毛是一个复杂的细胞器，非常重要，因为纤毛组装或功能的功能障碍会导致视网膜变性，肾脏疾病，智力低下，现场反相，多态度，多性疾病和其他疾病。对控制纤毛的形成，定位和结构完整性的机制的理解将导致发展纤毛疾病的治疗方法。