RNA trafficking in mitochondria

线粒体中的RNA运输

• 批准号: 10461154
• 负责人: Carla M Koehler
• 金额: $ 31.03万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10461154
• 关键词: Alcohols; Alleles; Area; Autoimmune Diseases; BAX gene; Base Pairing; Binding; Biogenesis; Biological Markers; Biological Models; Biology; Categories; Cells; Code; Critiques; Cytosol; DNA; Data; Defect; Development; Disease; Double Stranded RNA Virus; Double-Stranded RNA; Embryo; Enterobacteria phage P1 Cre recombinase; Enzymes; Equipment; Exoribonucleases; Fibroblasts; Generations; Goals; Grant; Health; Heart Diseases; Human; Immune response; Immunology; Infection; Influentials; Inherited; Innate Immune Response; Innate Immune System; Inner mitochondrial membrane; Interferon Type I; Ion Channel; Joints; Knockout Mice; Knowledge; Laboratories; Lead; Leigh Disease; Lipids; Liver diseases; Longitudinal Studies; Malignant Neoplasms; Mammalian Cell; Mass Spectrum Analysis; Mediating; Membrane; Mitochondria; Mitochondrial DNA; Mitochondrial Diseases; Mitochondrial Proteins; Mitochondrial RNA; Modeling; Molecular; Mus; Mutation; Neurodegenerative Disorders; Nuclear; Nucleic Acids; Paper; Pathologic; Pathway interactions; Patients; Pattern; Peptides; Physiological; Physiology; Point Mutation; Polyribonucleotide Nucleotidyltransferase; Process; Proteins; Publications; Publishing; RNA; RNA metabolism; Reagent; Research; Rest; Role; Signal Pathway; Signal Transduction; Specificity; Stress; Testing; Time; Training; Untranslated RNA; Work; base; biological adaptation to stress; cohort; deafness; exosome; extracellular; genetic deafness; helicase; innovation; knock-down; mitochondrial dysfunction; mitochondrial membrane; mouse model; mutant; nervous system disorder; novel; pathogen; prohibitin; receptor; response; sensor; trafficking

SUMMARY Mitochondria have numerous signaling pathways for conveying stress to the rest of a cell. Similar to pathogens that release pathogen-associated molecular patterns (PAMPs), mitochondria release novel damage-associated molecular patterns (DAMPs), including lipids, peptides, and mitochondrial DNA (mtDNA), that indicate mitochondrial stress. Mitochondrial double-stranded RNA (mtdsRNA) is a new class of DAMPs that is generated when the noncoding strand in mtRNA is not degraded efficiently and accumulates, allowing base-pairing with the coding strand. Under normal conditions, the helicase SUV3 unwinds the mtRNAs and polynucleotide phosphorylase (PNPase)ndegrades them. However, knockdown of SUV3 results in the accumulation of mtdsRNAs within mitochondria, and knockdown of PNPase leads to the release of the mtdsRNAs into the cytosol. Once in the cytosol, the mtdsRNAs are sensed by dsRNA sensors MDA5 and RIG-I, leading to the induction of the type I interferon pathway. The export of mtdsRNA is likely important as mtdsRNAs have been identified in the cytosol of patients with mutations in PNPT1, encoding PNPase, and in diseases including cancer, cardiac disease, alcohol-associated liver disease, and autoimmune diseases. The hypothesis that mtdsRNAs represent a new biomarker for mitochondrial dysfunction will be tested. As this is a new pathway, there is a critical gap in understanding the molecular rules and mechanisms by which mtdsRNAs cross the mitochondrial inner and outer membranes for cytosolic export. Our study goals are contained within three independent, but thematically connected, specific aims. In Aim 1, mtdsRNAs that are exported from mitochondria will be characterized with respect to size and sequence specificity. In addition, RNA modifying enzymes will be tested to determine which components are essential for the generation of mtdsRNAs. Aim 2 will focus on identification of outer and inner membrane channels and the role of PNPase in the trafficking of mtdsRNAs out of mitochondria. The third aim will define physiologic parameters that lead to the generation of mtdsRNAs and determination of the cytosolic dsRNA sensors that become activated during this process. Because mutations in PNPase lead to mitochondrial disease, mutants will be characterized to determine whether steps in the degradation and/or export of mtdsRNAs can be separated. Our study team has been characterizing PNPase and its function in mitochondria extensively. Unique model systems available for our work include a mouse model in which floxxed PNPT1 can be removed by the Cre recombinase, and mouse embryonic fibroblasts derived from this model. Results from this proposal will define the pathway for mtdsRNA trafficking out of mitochondria in detail and provide a platform for understanding how mutations in PNPase contribute to disease. Long-term, these studies may lead to establishing mtdsRNA as a new biomarker for mitochondrial dysfunction.

概括 线粒体具有许多信号通路，可以将应力传达给细胞的其余部分。类似于 释放病原体相关的分子模式（PAMP）的病原体，线粒体释放新颖 损伤相关的分子模式（湿），包括脂质，肽和线粒体DNA（mtDNA）， 这表明线粒体应力。线粒体双链RNA（mTDSRNA）是一类新的潮湿 当MTRNA中的非编码链没有有效降解并积累时，就会产生。 用编码链进行碱基配对。在正常条件下，旋转酶SUV3放松了MTRNA和 多核苷酸磷酸化酶（PNPase）Ndegrade。但是，SUV3的敲低导致 MTDSRNA在线粒体内的积累，PNPase的敲低导致释放 mtDSRNA进入细胞质。一旦进入细胞质，MTDSRNA就会被DSRNA传感器MDA5和 RIG-I，导致I型干扰素途径的诱导。 MTDSRNA的出口可能很重要，因为 在PNPT1，编码PNPase和In中的突变患者的细胞质中已经确定了mTDSRNA 包括癌症，心脏病，酒精相关肝病和自身免疫性疾病在内的疾病。 将测试MTDSRNA代表新的生物标志物的假设。 由于这是一条新途径，因此了解分子规则和机制存在关键的差距 MTDSRNA穿过胞质输出的线粒体内膜和外膜。我们的学习目标是 包含三个独立但主题连接的特定目标。在AIM 1中，MTDSRNA 从线粒体导出的大小和序列特异性将被表征。此外， 将测试RNA修饰酶以确定哪些组件对于生成至关重要 mtdsrnas。 AIM 2将集中于识别外膜和内膜通道以及PNPase在 从线粒体中贩运mtdsrnas。第三个目标将定义导致的生理参数 MTDSRNA的产生和胞质DSRNA传感器的测定，这些传感器在 这个过程。由于PNPase中的突变导致线粒体疾病，因此将其特征为 确定MTDSRNA降解和/或导出的步骤是否可以分开。 我们的研究团队一直在广泛地表征PNPase及其在线粒体中的功能。独特的 可用于我们工作的模型系统包括鼠标模型，其中Floxxed PNPT1可以通过 CRE重组酶和源自该模型的小鼠胚胎成纤维细胞。该提议的结果将 定义MTDSRNA从线粒体中贩运的途径，并为 了解PNPase中的突变如何促进疾病。长期，这些研究可能导致 建立MTDSRNA作为线粒体功能障碍的新生物标志物。