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: 10224752
• 负责人: Jaan Mannik
• 金额: $ 29.35万
• 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 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224752
• 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.

项目摘要/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，以增强我们对细菌基本细胞过程的理解。恰当的 细胞分裂和染色体隔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中，第一个 通过正确定位细胞分裂蛋白来实现可靠的染色体分配： Divisome。已知大肠杆菌中的三个分子系统可以调节FTSZ丝的组装到早期 Divisome（Z形）。其中包括最小系统和核苷闭塞因子SLMA，这两者都 通过负调节确定Z形环的定位。我们最近发现大肠杆菌也藏有 一个积极的监管系统，称为TER链接。 Z环相关蛋白质ZAPA，ZAPB和DNA 结合蛋白MATP参与了这种机制。除了定位Z形环， 细胞分裂晚期的染色体也负责其适当的分配。在大肠杆菌DNA泵中 FTSK是这一运动的主要来源，但它可能不是唯一的。虽然关键因素包括 这些协调系统已被鉴定出来，许多蛋白质 - 蛋白质相互作用已映射出来， 对这些相互作用如何共同导致动态细胞水平行为的有限理解。尤其， 只有非常近似的理解如何以及何时形成Z形。知识也有限 染色体DNA移动并在细胞分裂期间分配。这两个过程对于细胞存活都是必不可少的。 该建议将通过将分子生物学和遗传工具与新颖的最新技术相结合来填补这些空白 显微镜和图像分析技术。除了实验研究外，我们还将使用计算机建模 为这些过程开发概念框架。具体而言，我们将确定如何FTSZ原丝 形成并在细胞中组装成一个粘性的Z环（AIM 1）。我们还将调查这些步骤是如何的 在空间和时间上受到Z形环与复制末端之间的耦合的影响 通过TER连锁蛋白（AIM 2）染色体。除了研究细菌核苷们如何影响细胞 分裂我们还将确定细胞分裂如何作用于核苷上并在细胞期间移动染色体DNA 部门（目标3）。从该项目中获得的知识将增强我们对基本蜂窝的理解 细菌中的过程，并提供了设计有效抗菌疗法以对抗多药的框架 抗性细菌。