Olfactory Singaling, Cilia, and Sensory Disorders

嗅觉信号、纤毛和感觉障碍

基本信息

批准号：
7507129
负责人：
Jeffrey Martens
金额：
$ 37.79万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-17 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7507129
关键词：
Affect Afferent Neurons Amino Acid Sequence Area Arts Basic Science Binding Biochemical Genetics Carrier Proteins Cell surface Cilia Class Clinical Clinical Research Complex Data Defect Dendrites Detection Diffusion Disease Dominant-Negative Mutation Etiology Functional disorder GTP-Binding Proteins Gene Mutation General Population Goals Guanine Nucleotide Exchange Factors Guanosine Triphosphate Phosphohydrolases Hair Hereditary Disease Human Impairment In Vitro Kinesin Knowledge Link Localized Measures Mediating Methods Microtubules Modeling Molecular Motor Movement Multiprotein Complexes Mus Mutation Nasal cavity Neurons Nose Odors Pathogenesis Pathway interactions Patients Peptide Sequence Determination Perception Population Process Property Protein Biosynthesis Protein Isoforms Proteins Public Health RNA Interference RNA Splicing Range Regulation Research Retina Retinitis Pigmentosa Role Sensory Sensory Disorders Side Signal Transduction Signaling Molecule Signaling Protein Smell Perception Sorting - Cell Movement System Techniques Testing Variant cilium biogenesis fluorescence imaging gain of function genetic regulatory protein in vivo insight intracellular protein transport kinetosome loss of function mutant neuronal cell body novel protein localization location protein transport receptor expression trafficking

项目摘要

DESCRIPTION (provided by applicant): Olfactory Signaling, Cilia, and Sensory Disorders The long-range goal of this proposal is to elucidate the mechanisms underlying the transport of odorant signaling proteins into mammalian olfactory cilia and their alterations in cilia-related disorders. Olfactory dysfunction in the general population is frequent, affecting at least 2.5 million people in the U.S. alone. In at least 20% of the cases the etiology of the chemosensory disturbance cannot be identified. Recently, we were one of the first to demonstrate olfactory dysfunction as a clinical manifestation of an emerging class of human genetic disorders, termed ciliopathies, which involve defects in ciliary assembly and/or protein transport. The enrichment of signaling proteins in the cilia of olfactory sensory neurons (OSNs) is essential for odor detection, however surprisingly little is known regarding the mechanisms regulating protein trafficking into olfactory cilia. We have recently identified 3 novel regulatory proteins as part of a multiprotein complexe in the olfactory system that likely participates in important steps of ciliary transport. The first, CEP290, is a basal body protein localized to dendritic knobs of OSNs. We have discovered that hypomorphic mutations in this protein selectively inhibit G-protein trafficking to cilia resulting in severe impairment of olfactory function. The second, a splice variant of Retinitis Pigmentosa GTPase Regulator (RPGR), RPGRORF15, is associated with sensory dysfunction in the retina. RPGRORF15 is localized to the knobs and dendrites of OSNs and a mutation of this isoform results in olfactory dysfunction in mice. The third, KIF17, is a kinesin motor protein that we have shown, in a heterologous system, to be required for ciliary enrichment of the olfactory CNG channel and is endogenously expressed in the cilia of native OSNs. We have found that each of these components is associated with other known ciliary, basal body, and microtubule transport proteins in OSNs however, their precise role in the mammalian olfactory system is unclear. We hypothesize that, in OSNs, CEP290, RPGRORF15, and KIF17 are components of the ciliary transport pathway which orchestrate the trafficking of signaling proteins by assembly of multiprotein complexes in the basal body/cilia compartment. Mutations in these components alter protein interactions leading to the mislocalization of signaling molecules and a loss of olfactory function. Therefore, in Specific Aim 1 we will define the mechanism by which CEP290 regulates trafficking of olfactory G-proteins to cilia. In Specific Aim 2, we will elucidate the function of RPGRORF15 in olfactory function and protein trafficking to cilia. In Specific Aim 3, we will determine the role of KIF17 in olfactory signaling protein localization to cilia. Successful completion of our proposed studies will afford new insights into the poorly understood mechanisms of ciliary trafficking in OSNs and the regulation of sensory perception while emphasizing that olfactory dysfunction represents an important clinical manifestation of ciliary disease. PUBLIC HEALTH RELEVANCE In the nose, neurons involved in smell have many cilia, hair-like projections into the nasal cavity, which contain all of the proteins responsible for detecting odors. The goal of this proposal is to understand how olfactory proteins get to the cilia and why genetic mutations in proteins of these cilia result in the loss of smell.

描述（由申请人提供）：嗅觉信号传导，纤毛和感觉障碍该提案的长期目标是阐明气味信号蛋白转运到哺乳动物嗅觉纤毛的机制及其在纤毛相关灾难中的改变。普通民众的嗅觉功能障碍经常出现，仅在美国就会影响至少250万人。在至少20％的情况下，无法确定化学感应障碍的病因。最近，我们是最早证明嗅觉功能障碍作为新兴人类遗传疾病的临床表现，称为纤毛病，涉及纤毛组装和/或蛋白质转运的缺陷。信号蛋白在嗅觉感觉神经元（OSN）的纤毛中的富集对于气味检测至关重要，但是对于调节蛋白质运输到嗅觉纤毛的蛋白质的机制而言，鲜为人知。我们最近已经确定了3种新型调节蛋白是嗅觉系统中多蛋白复合物的一部分，该蛋白可能参与了睫状运输的重要步骤。第一个是CEP290，是一种基础体蛋白，位于OSN的树突旋钮上。我们已经发现，该蛋白质中的低形态突变有选择地抑制G蛋白运输到纤毛，从而导致嗅觉功能严重损害。第二个是视网膜炎的色素性GTPase调节剂（RPGR）RPGRORF15的剪接变体与视网膜中的感觉功能障碍有关。 RPGRORF15位于OSN的旋钮和树突上，并且该同工型的突变导致小鼠嗅觉功能障碍。第三个KIF17是一种动力蛋白运动蛋白，我们在异源系统中显示的纤毛富集嗅觉CNG通道所必需，并在天然OSN的纤毛中表达。我们发现，这些成分中的每一个都与OSN中其他已知睫状，基体和微管转运蛋白相关联，但是它们在哺乳动物嗅觉系统中的精确作用尚不清楚。我们假设在OSN中，CEP290，RPGRORF15和KIF17是睫状传输途径的组成部分，通过在基础体内/CILIA隔室中组装多蛋白复合物来协调信号蛋白的运输。这些成分中的突变改变了蛋白质相互作用，导致信号分子的错误定位和嗅觉功能的丧失。因此，在特定目标1中，我们将定义CEP290调节嗅觉G蛋白向纤毛的机制。在特定的目标2中，我们将阐明RPGRORF15在嗅觉功能和蛋白质运输中的功能。在特定的目标3中，我们将确定KIF17在嗅觉信号传导蛋白定位到纤毛中的作用。成功完成我们提出的研究将为OSN中睫状运输的机制和感觉知觉的调节提供新的见解，同时强调嗅觉功能障碍代表了睫状性疾病的重要临床表现。鼻子中的公共卫生相关性，涉及气味的神经元在鼻腔中有许多纤毛，类似于头发的凸起，其中包含所有负责检测气味的蛋白质。该提案的目的是了解嗅觉蛋白如何进入纤毛，以及为什么这些纤毛的蛋白质中的遗传突变会导致气味降低。