Molecular basis of ionizing radiation resistance

抗电离辐射的分子基础

• 批准号: 9239223
• 负责人: Michael M. Cox
• 金额: $ 29.33万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9239223
• 关键词: Amaze; Bacteria; Bioremediations; Cell Wall; Cells; Complex; DNA Repair; Deinococcus; Deinococcus radiodurans; Directed Molecular Evolution; Dose; Electrons; Engineering; Escherichia coli; Evolution; Exhibits; Genes; Genetic; Genomics; Goals; Growth; Home environment; Human; Individual; Industry; Ionizing radiation; Laboratories; Mammals; Medical; Medicine; Membrane; Metabolic; Metals; Modernization; Molecular; Mutation; Mutation Analysis; Pathway interactions; Phenotype; Photons; Physiology; Population; Process; Proteins; Proteome; Protocols documentation; Radiation; Radioactive Waste; Resistance; Resources; Roentgen Rays; Salmonella enterica; Site; Source; Structure; Survivors; System; Systems Biology; Time; Work; design; ds-DNA; experimental study; genetic analysis; innovation; irradiation; macromolecule; metabolome; microbial; microorganism; novel; novel strategies; oxidation; particle; pregnant; radiation resistance; radioresistant; repaired; resistant strain; transcriptome

Project Summary/Abstract In this project, we will systematically define the genetic and cellular adaptations associated with an extremophile phenotype in bacteria – extraordinary resistance to the effects of ionizing radiation (IR). Instead of studying prototypical IR resistant species such as Deinococcus radiodurans, we are generating IR resistant Escherichia coli populations by directed evolution. The resulting strains approach, and in some cases exceed the levels of IR resistance seen in Deinococcus. Analysis of the mutations underlying the acquired phenotype will allow us to quickly home in on the key cellular innovations. The ultimate goal is to define ALL processes and mechanisms that contribute to an extreme IR resistance phenotype. The directed evolution of this phenotype in E. coli provides a window that makes this possible. In this work we will both exploit and expand an existing resource of four highly evolved populations of E. coli. Using directed evolution, all of these have acquired high levels of IR resistance. The populations are designated IR-1-20, IR- 2-20, IR-3-20, and IR-4-20. We have already defined the mutations most relevant to the phenotype in both IR-2-20 and IR-3-20. In addition, we are currently generating four new evolved populations from scratch, using a different type of radiation source, and further evolving the four existing populations. There are four specific aims: Aim 1 focuses on the evolution of new and existing populations, as well as definition of the mutations that make substantial contributions to the phenotype. Defined strains with key contributing mutations, isolated in an otherwise wild type background, will be constructed. Aim 2 represents a general effort to use the modern resources of systems biology to thoroughly characterize the evolved populations and single colony isolates derived from them. Aim 3 will focus on an exploration of one particular contributing mechanism of IR resistance involving genetic alterations in genes encoding proteins involved in replication restart. Aim 4 is the capstone. We will use information gained from aims 1-3 to transfer the IR resistance phenotype intact by introducing a defined set of mutations into Salmonella enterica.

项目摘要/摘要 在这个项目中，我们将系统地定义遗传和细胞适应 与细菌中的极端表型相关 - 特殊抗性 电离辐射（IR）的影响。而不是研究原型IR 抗性物种，例如deinococcus radiodurans，我们正在产生IR抗性 大肠杆菌种群通过定向进化。由此产生的应变方法， 在某些情况下，超过了脱氧巨头中的IR抗性水平。分析 在获得的表型基础的突变中，将使我们能够快速 在关键的蜂窝创新中回家。最终目标是定义所有目标 导致极端抗性的过程和机制 表型。大肠杆菌中这种表型的定向演变提供了 窗口使这成为可能。 在这项工作中，我们将利用和扩展四个现有资源 大肠杆菌的高度进化人群。使用定向进化，所有这些都有 获得了高水平的IR耐药性。人口被指定为IR-1-20，IR- 2-20，IR-3-20和IR-4-20。我们已经定义了最相关的突变 IR-2-20和IR-3-20的表型。此外，我们目前是 使用不同类型的 辐射源，并进一步发展了四个现有人群。有 四个具体目标： AIM 1专注于新的和现有人群的发展以及 对表型做出重大贡献的突变的定义。 定义的菌株具有关键贡献突变，在原本野外隔离 类型背景将被构造。 AIM 2代表了使用的一般努力 系统生物学的现代资源以彻底表征进化 种群和单个菌落分离株从中得出。 AIM 3将重点放在 探索涉及的IR抗性的一种特定促进机制 重新启动参与复制的蛋白质的基因的遗传改变。 AIM 4是顶峰。我们将使用AIMS 1-3获得的信息转移 通过将一组定义的突变集中在 沙门氏菌肠。