Mechanisms of Transcription-Coupled DNA Supercoiling

转录偶联 DNA 超螺旋机制

基本信息

批准号：
8268387
负责人：
Fenfei Leng
金额：
$ 23.99万
依托单位：
FLORIDA INTERNATIONAL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-05-01 至 2014-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8268387
关键词：
Affect Antineoplastic Agents Bacteriophage lambda Bacteriophages Binding Sites Biological Process Camptothecin Cells Chromosome Structures Coliphages Complex Coupled DNA DNA Sequence DNA Topoisomerases DNA biosynthesis DNA-Binding Proteins DNA-Directed RNA Polymerase Data Development Diffusion Doxorubicin Enzymes Escherichia coli Florida Foundations Fragile X Syndrome Funding Gene Expression Genes Genetic Recombination Genetic Transcription Genome Stability Goals Grant Health Hereditary Disease Human Huntington Disease In Vitro International Isopropyl Thiogalactoside Knowledge Laboratories Lactose Malignant Neoplasms Modeling Molecular Nucleoproteins Plant Roots Play Point Mutation Process Processed Genes Progress Reports Proteins Research Resources Role Salmonella typhimurium Sequence-Specific DNA Binding Protein Superhelical DNA System Testing Transcription Initiation Twin Multiple Birth Universities Work base career in vivo innovation novel plasmid DNA programs promoter public health relevance stem

项目摘要

DESCRIPTION (provided by applicant): A fundamental gap exists in understanding how transcription by a translocating RNA polymerase modulates DNA topology and how transcription-coupled DNA supercoiling (TCDS) activates gene expression. For instance, the roles of sequence-specific DNA-binding proteins in TCDS are still not fully understood. The long- term goal of the proposed research is to understand how transcription affects DNA topology, chromosome structure, and the coupled DNA transactions, such as DNA replication and gene expression. The objectives of this application are to determine how certain sequence-specific DNA-binding proteins, such as bacteriophage lambda DNA replication initiator O protein and lactose repressor, regulate TCDS in vitro and in E. coli and to determine the mechanism by which TCDS activates gene expression. The central hypothesis is that the "twin- supercoiled-domain" model is the mechanism responsible for TCDS in which nucleoprotein complexes, especially those containing stable toroidal supercoils assembled from tightly-wrapping DNA around certain sequence-specific DNA-binding proteins, can form topological barriers that impede the diffusion and merger of independent chromosomal supercoil domains. In this case, the "confined" localized DNA supercoils may activate or inhibit the coupled DNA transactions. This hypothesis has been formulated on the basis of strong preliminary data produced in our laboratory and will be tested by pursuing four specific aims: 1) to determine the mechanisms by which certain sequence-specific DNA-binding proteins potently stimulate TCDS in the defined protein systems; 2) to study effects of the sequence-specific DNA-binding proteins on TCDS in E. coli; 3) to develop a novel system, based on a linear coliphage N15, to study activation of the Salmonella typhimurium leu-500 promoter by TCDS; 4) to establish a nationally competitive research program at Florida International University (the PI's development objective). This application will provide important knowledge for understanding the mechanism of TCDS and its roles in gene expression. It will also provide the necessary resources for the PI to transit to non-SCORE support within a four-year funding period. Public Health Relevance: The significance of this research stems from its potential to provide a basis for better understanding of an essential biological process: gene transcription and expression. It also provides a foundation for further understanding DNA topology, which plays an important role in genome stability and certain human hereditary diseases, such as fragile X syndrome and Huntington's disease.

描述（由申请人提供）：存在基本差距在理解转移RNA聚合酶如何调节DNA拓扑以及转录耦合DNA Supersoiling（TCDS）如何激活基因表达的基本差距。例如，尚未完全了解序列特异性DNA结合蛋白在TCD中的作用。拟议的研究的长期目标是了解转录如何影响DNA拓扑，染色体结构和耦合DNA交易，例如DNA复制和基因表达。该应用的目标是确定某些序列特异性的DNA结合蛋白（例如噬菌体Lambda DNA复制引发剂O蛋白和乳糖抑制剂）如何在大肠杆菌和大肠杆菌中调节TCD，并确定TCDS通过其激活基因表达的机制。 The central hypothesis is that the "twin- supercoiled-domain" model is the mechanism responsible for TCDS in which nucleoprotein complexes, especially those containing stable toroidal supercoils assembled from tightly-wrapping DNA around certain sequence-specific DNA-binding proteins, can form topological barriers that impede the diffusion and merger of independent chromosomal supercoil domains.在这种情况下，“限制”的局部DNA超元可能会激活或抑制耦合的DNA交易。该假设是根据我们实验室中产生的强初级数据提出的，将通过追求四个具体目的来测试：1）确定某些序列特异性DNA结合蛋白在定义的蛋白质系统中有效刺激TCD的机制； 2）研究序列特异性DNA结合蛋白对大肠杆菌中TCD的影响； 3）基于线性coliphage n15开发一种新型系统，以研究TCD的typhimurium leu-500启动子的激活； 4）在佛罗里达国际大学（PI的发展目标）建立全国竞争性研究计划。该应用将提供重要的知识，以了解TCD的机制及其在基因表达中的作用。它还将为PI提供必要的资源，以在四年的资金期内过渡到非得分支持。公共卫生相关性：这项研究的意义源于其潜力，即提供更好地理解基本生物过程的基础：基因转录和表达。它还为进一步理解DNA拓扑结构提供了基础，DNA拓扑在基因组稳定性和某些人类遗传疾病中起着重要作用，例如脆弱的X综合征和亨廷顿氏病。