Mechanisms of somatic mtDNA mutation detection and elimination

体细胞线粒体DNA突变检测和消除机制

基本信息

批准号：
8914069
负责人：
Leo J Pallanck
金额：
$ 23.18万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8914069
关键词：
Aging Animal Model Autophagocytosis Biological Assay Biological Models Biological Process Collaborations DNA DNA-Directed DNA Polymerase Diabetes Mellitus Disease Dose Drosophila genus Drosophila melanogaster Elderly Excision Frequencies Genetic Genetic Models Health Knowledge Lead Locomotion Longevity Lysosomes Malignant Neoplasms Mediating Methods Mitochondria Mitochondrial DNA Molecular Morphogenesis Mutate Mutation Mutation Detection PINK1 gene Parkinson Disease Pathogenesis Pathology Phenotype Physiological Play Process Protein-Serine-Threonine Kinases Proteomics Quality Control Role Severity of illness Surface System Testing Tissues Toxic effect Transgenes Transgenic Organisms Ubiquitin-Protein Ligase Complexes Ubiquitination Ursidae Family Work fly genetic manipulation human disease in vivo insight locomotor deficit mitochondrial DNA mutation mutant next generation sequencing novel overexpression parkin gene/protein research study therapy development trafficking ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): Mitochondrial DNA (mtDNA) mutations cause a number of severe maternally transmitted diseases, and the accumulation of somatic mtDNA mutations is implicated in aging and common diseases of the elderly. These mtDNA mutations often coexist with normal mtDNA, a condition known as heteroplasmy. The ratio of mutated to wild-type mtDNA plays a crucial role in the pathogenesis of heteroplasmic disorders, but the mechanisms that influence this ratio are largely unknown. The long-term objective of our work is to define the cellular mechanisms that govern the frequency of deleterious mtDNA mutations in heteroplasmic somatic tissues. Recent work on the Parkinson's disease-related factors PINK1 and Parkin has revealed that these factors are components of a mitochondrial quality control system (MQCS) that can detect dysfunctional mitochondria, and, in collaboration with other cellular factors, promote their autophagic degradation. We hypothesize that the MQCS acts to reduce the frequency of deleterious heteroplasmic mtDNA mutations by detecting dysfunctional mitochondria that bear mutant DNA and targeting them for degradation. To test this hypothesis, we propose to use the model organism Drosophila melanogaster to pursue three aims. The first aim will examine the influence of genetic alterations of the MQCS on the phenotypes of a Drosophila strain with an increased mtDNA mutation frequency. The second aim will examine the influence of genetic perturbations of the MQCS on the mtDNA mutation frequency using a novel next-generation sequencing method. Finally, the third aim will use a recently developed in vivo assay of mitochondrial turnover to test whether mtDNA mutations promote mitochondrial turnover, and whether genetic perturbations of the MQCS influence the effects of mtDNA mutations on turnover. Our studies will contribute to an understanding of the molecular mechanisms that influence heteroplasmy, and this knowledge could ultimately lead to the development of treatments for diseases caused by mtDNA mutations.

描述（申请人提供）：线粒体DNA（mtDNA）突变导致多种严重的母婴传播疾病，体细胞mtDNA突变的积累与衰老和老年人常见疾病有关。这些 mtDNA 突变通常与正常 mtDNA 共存，这种情况称为异质性。突变型与野生型 mtDNA 的比例在异质性疾病的发病机制中起着至关重要的作用，但影响该比例的机制在很大程度上尚不清楚。我们工作的长期目标是确定控制异质体细胞组织中有害 mtDNA 突变频率的细胞机制。最近对帕金森病相关因子 PINK1 和 Parkin 的研究表明，这些因子是线粒体质量控制系统 (MQCS) 的组成部分，可以检测功能失调的线粒体，并与其他细胞因子协作，促进其自噬降解。我们假设 MQCS 通过检测携带突变 DNA 的功能失调线粒体并靶向降解它们来降低有害异质 mtDNA 突变的频率。为了检验这一假设，我们建议使用模式生物果蝇来实现三个目标。第一个目标是检查 MQCS 的遗传改变对 mtDNA 突变频率增加的果蝇菌株表型的影响。第二个目标是使用一种新型的下一代测序方法来检查 MQCS 的遗传扰动对 mtDNA 突变频率的影响。最后，第三个目标将使用最近开发的线粒体周转体内检测来测试 mtDNA 突变是否促进线粒体周转，以及 MQCS 的遗传扰动是否影响 mtDNA 突变对周转的影响。我们的研究将有助于理解影响异质性的分子机制，而这些知识最终可能导致 mtDNA 突变引起的疾病治疗方法的开发。