Mechanisms of mitochondrial transcription

线粒体转录机制

• 批准号: 8371513
• 负责人: MIGUEL GARCIA-DIAZ
• 金额: $ 29.65万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8371513
• 关键词: Affect; Aminoglycosides; Architecture; Bacteriophages; Biochemical; Biogenesis; Cardiovascular Diseases; Complex; Crystallography; DNA; DNA-Directed RNA Polymerase; Data; Defect; Development; Diabetes Mellitus; Disease; Electron Microscopy; Enzymes; Gene Expression; Gene Expression Process; Genetic; Genetic Transcription; Human Pathology; Individual; Inherited; Knowledge; Lead; Light; Malignant Neoplasms; Maps; Mediating; Messenger RNA; Methods; Methylation; Methyltransferase; Mitochondria; Mitochondrial Diseases; Mitochondrial Proteins; Mitochondrial RNA; Modeling; Molecular; Molecular Genetics; Mus; Mutation; N-terminal; Neurodegenerative Disorders; Nucleic Acids; Pathogenesis; Pathology; Peptide Initiation Factors; Population; Process; Production; Proteins; RNA; RNA methylation; Resolution; Ribosomal RNA; Ribosomes; Role; S-Adenosylmethionine; Specificity; Structural Models; Structure; Techniques; Toxic effect; Transcription Initiation; Transcription Process; Transfer RNA; Translations; X-Ray Crystallography; age related; base; deafness; human disease; improved; in vitro activity; insight; interdisciplinary approach; mitochondrial dysfunction; novel; protein protein interaction; stem; transcription factor

DESCRIPTION (provided by applicant): Genetic or age-related defects in mitochondrial gene expression can reduce or eliminate mitochondrial function and cause multiple human pathologies, including neurodegenerative and cardiovascular disease, diabetes and cancer. Mitochondrial transcription is a key process for gene expression, and accordingly some of these pathogenic alterations have been associated with proteins involved in transcription. However, our functional understanding of the different components of the transcription machinery in mitochondria is relatively poor. Characterizing the molecular mechanisms underlying mitochondrial transcription will allow us to understand how small genetic or environmental alterations in this process can result in gene expression deficiencies and the development of mitochondrial pathology. This proposal aims to provide functional insight into the process of mitochondrial transcription and investigate the importance of the rRNA methyltransferase activities present in transcription factors. We aim to unravel the mechanism of transcription initiation, the connections between transcription and ribosome biogenesis and the relationship between transcriptional defects and mitochondrial disease. The proposal has three aims: (i) to investigate the structural and functional differences between two transcription factors related to 16S rRNA methyltransferases, TFB1M and TFB2M, and to study the specificity of their interaction with their nucleic acid substrates; (ii) to investigate the methyltransferase activitie of TFB1M and TFB2M, their importance for transcription and ribosome biogenesis and their relationship with maternally inherited deafness; (iii) to determine the mechanisms of transcription initiation, the protein-protein interactions necessary for the process and the architecture of the transcription machinery. The proposal will take advantage of substantial preliminary data, including two novel crystal structures, the discovery of a novel interaction critical for initiation and the development of new methods to study the rRNA methyltransferase activities in vitro. We will apply various molecular genetics, biochemical and biophysical techniques to investigate the functional interactions necessary for transcription and the enzymatic activities of TFB1M and TFB2M. Electron microscopy, small angle x-ray scattering and X-ray crystallography will be used to provide additional structural insight and, in turn, facilitate our functional understanding of the process. The expected results will dramatically increase our knowledge of mitochondrial transcription, the individual roles of transcription factors, the relationships between transcription and ribosome biogenesis and the molecular basis of maternally inherited deafness. Ultimately, improving our mechanistic understanding of the transcription process will help clarify the relationship between transcription, mitochondrial dysfunction and disease. PUBLIC HEALTH RELEVANCE: Deficiencies in mitochondrial gene expression affect a large proportion of the population and can cause or contribute to disease development. This proposal will study the molecular mechanisms responsible for transcription, a central process in gene expression, and will improve our understanding of the mechanisms by which deficiencies in this process can lead to mitochondrial pathologies. The expected results will be relevant to our understanding of mitochondrial function, the development of mitochondrial diseases and the contribution of mitochondrial genetic alterations to the onset of age-related pathologies.

描述（由申请人提供）：线粒体基因表达中的遗传或年龄相关缺陷可降低或消除线粒体功能，并导致多种人类病理，包括神经退行性疾病和心血管疾病、糖尿病和癌症。线粒体转录是基因表达的关键过程，因此这些致病性改变中的一些与参与转录的蛋白质相关。然而，我们对线粒体中转录机制的不同组成部分的功能理解相对较差。表征线粒体转录的分子机制将使我们能够了解在这一过程中微小的遗传或环境改变如何导致基因表达缺陷和线粒体病理学的发展。该建议旨在为线粒体转录过程提供功能性见解，并研究转录因子中存在的rRNA甲基转移酶活性的重要性。我们的目标是阐明转录起始的机制，转录和核糖体生物合成之间的联系，以及转录缺陷和线粒体疾病之间的关系。该提案有三个目标：（i）研究16SrRNA甲基转移酶相关转录因子TFB1M和TFB2M的结构和功能差异，以及它们与核酸底物相互作用的特异性，（ii）研究TFB1M和TFB2M的甲基转移酶活性，它们在转录和核糖体生物合成中的重要性，以及它们与母系遗传性耳聋的关系;（iii）确定转录起始的机制、该过程所必需的蛋白质-蛋白质相互作用以及转录机器的结构。该提案将利用大量的初步数据，包括两种新的晶体结构，发现一种新的相互作用的关键启动和新方法的发展，研究rRNA甲基转移酶的体外活动。我们将应用各种分子遗传学，生物化学和生物物理技术来研究转录所需的功能相互作用和TFB1M和TFB2M的酶活性。电子显微镜，小角度X射线散射和X射线晶体学将被用来提供额外的结构洞察力，反过来，促进我们的功能理解的过程。预期的结果将大大增加我们的线粒体转录，转录因子的个人作用，转录和核糖体生物合成之间的关系和母系遗传性耳聋的分子基础的知识。最终，提高我们对转录过程的机械理解将有助于澄清转录，线粒体功能障碍和疾病之间的关系。 公共卫生关系：线粒体基因表达缺陷影响大部分人群，并可能导致或促成疾病发展。 这项建议 将研究负责转录的分子机制，这是基因组中的一个中心过程。 表达，并将提高我们对缺陷的机制的理解， 该过程可导致线粒体病变。 预期结果将与我们的 了解线粒体功能、线粒体疾病的发展以及线粒体遗传改变对年龄相关病理的影响。