Coordination mechanisms between cell division and chromosome segregation in E. coli

大肠杆菌细胞分裂和染色体分离之间的协调机制

• 批准号: 9980944
• 负责人: Jaan Mannik
• 金额: $ 28.99万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9980944
• 关键词: Address; Affect; Anti-Bacterial Agents; Bacteria; Behavior; Biochemistry; Biological Assay; Biophysics; Cell Cycle; Cell Size; Cell Survival; Cell division; Cell physiology; Cells; Cellular biology; Chromosome Segregation; Chromosomes; Color; Computer Models; Coupling; DNA; DNA biosynthesis; DNA-Binding Proteins; DNA-Protein Interaction; Data; Ensure; Escherichia coli; Filament; Fluorescence; Fluorescence Microscopy; Goals; Growth; Image Analysis; In Vitro; Kinetics; Knowledge; Lead; Link; Location; Molecular; Molecular Biology; Molecular Genetics; Molecular Structure; Motor; Movement; Multiple Bacterial Drug Resistance; Pharmaceutical Preparations; Polymers; Positioning Attribute; Process; Protein-Protein Interaction Map; Proteins; Pump; Regulation; Research; Source; Structure; System; Techniques; Testing; Therapeutic; Time; Work; antimicrobial; base; chromosome movement; chromosome replication; cohesion; combat; daughter cell; design; experimental study; fitness; genetic information; microscopic imaging; novel; quantitative imaging; segregation; stem; temporal measurement; time use; tool; z-ring

PROJECT SUMMARY/ABSTRACT The aim of the proposed work is to investigate key coordination mechanisms between cell division and chromosome segregation to enhance our understanding of fundamental cellular processes in bacteria. Proper spatial and temporal coordination between cell division and chromosome segregation must guarantee that chromosomes partition correctly to daughter cells. In Escherichia coli and many other bacterial species the first step in reliable partitioning of chromosomes is achieved via proper positioning of cell division proteins: the divisome. Three molecular systems in E. coli are known to regulate the assembly of FtsZ filaments to an early divisome (the Z-ring). These include the Min system and the nucleoid occlusion factor SlmA, which both determine the localization of the Z-ring via negative regulation. We recently discovered that E. coli also harbors a positive regulatory system, referred to as the Ter linkage. Z-ring associated proteins ZapA, ZapB and DNA binding protein MatP are involved in this mechanism. In addition to positioning of the Z-ring, the movement of chromosomes in late stages of cell division is also responsible for their proper partitioning. In E. coli DNA pump FtsK is the main source of this movement but it might not be the only one. Although the key factors comprising these coordination systems have been identified and many protein-protein interactions mapped out, there is limited understanding of how these interactions collectively lead to dynamic cellular level behaviors. In particular, there is only a very approximate understanding how and when Z-ring forms. There is also limited knowledge how chromosomal DNA moves and is partitioned during cell division. Both processes are essential for cell survival. This proposal will fill these gaps by combining molecular biology and genetic tools with novel state-of-the art microscopy and image analysis techniques. In addition to experimental studies we will use computer modelling to develop a conceptual framework for these processes. Specifically, we will determine how FtsZ protofilaments form and assemble to a cohesive Z-ring in the cell (Aim 1). We will also investigate how these steps are influenced spatially and temporally by coupling between Z-ring and replication terminus region of the chromosome via the Ter linkage proteins (Aim 2). In addition to studying how bacterial nucleoids affect cell division we will also determine how cell division acts on nucleoids and moves chromosomal DNA during cell division (Aim 3). The knowledge gained from this project will enhance our understanding of fundamental cellular processes in bacteria and provide a framework for designing effective antibacterial therapies to combat multidrug resistant bacteria.

项目概要/摘要 拟议工作的目的是研究细胞分裂和细胞分裂之间的关键协调机制 染色体分离可以增强我们对细菌基本细胞过程的理解。恰当的 细胞分裂和染色体分离之间的空间和时间协调必须保证 染色体正确分配给子细胞。在大肠杆菌和许多其他细菌物种中 染色体可靠划分的步骤是通过细胞分裂蛋白的正确定位来实现的： 分裂的。已知大肠杆菌中的三个分子系统可调节 FtsZ 丝的早期组装 分裂（Z 形环）。其中包括 Min 系统和类核闭塞因子 SlmA，它们都 通过负调节确定 Z 环的定位。我们最近发现大肠杆菌还含有 积极的监管体系，简称Ter链接。 Z 环相关蛋白 ZapA、ZapB 和 DNA 结合蛋白 MatP 参与了这一机制。除了 Z 形环的定位之外， 细胞分裂后期的染色体也负责它们的正确分配。在大肠杆菌 DNA 泵中 FtsK 是这一运动的主要来源，但可能不是唯一的来源。虽然关键因素包括 这些协调系统已被识别，并且许多蛋白质-蛋白质相互作用已被绘制出来，有 对这些相互作用如何共同导致动态细胞水平行为的理解有限。尤其， Z 形环是如何以及何时形成的，目前只有非常粗略的了解。知识也有限 染色体 DNA 在细胞分裂过程中移动并分裂。这两个过程对于细胞生存都是必需的。 该提案将通过将分子生物学和遗传工具与新颖的最先进技术相结合来填补这些空白 显微镜和图像分析技术。除了实验研究之外，我们还将使用计算机建模 为这些过程制定一个概念框架。具体来说，我们将确定 FtsZ 原丝如何 在细胞中形成并组装成粘性 Z 形环（目标 1）。我们还将研究这些步骤是如何进行的 Z环和复制末端区域之间的耦合在空间和时间上产生影响 通过 Ter 连接蛋白连接染色体（目标 2）。除了研究细菌核苷如何影响细胞 我们还将确定细胞分裂如何作用于核仁并在细胞分裂过程中移动染色体 DNA 部门（目标 3）。从这个项目中获得的知识将增强我们对基本细胞的理解 细菌中的过程，并为设计有效的抗菌疗法来对抗多种药物提供框架 耐药细菌。