Targeting and assembly of E. coli cell division proteins

大肠杆菌细胞分裂蛋白的靶向和组装

• 批准号: 7924945
• 负责人: WILLIAM MARGOLIN
• 金额: $ 35.4万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7924945
• 关键词: Actins; Address; Affect; Bacteria; Bypass; Cell Size; Cell division; Cell physiology; Cells; Chromosome Segregation; Chromosomes; Contracts; Cytokinesis; Cytoplasm; Data; Daughter; Escherichia coli; Event; Genes; Genetic; Goals; Grant; Image; Individual; Knowledge; Location; Membrane; Modeling; Molecular; Molecular Machines; Mutation; Pathway interactions; Protein Biochemistry; Proteins; Recruitment Activity; Recycling; Research; Rest; Role; Set protein; Site; Structure; Surface; Testing; Time; Tubulin; Work; antimicrobial; base; constriction; cost; frontier; gain of function; mutant; programs; protein function; protein protein interaction; reconstitution; stoichiometry

Before any cell divides to yield viable daughters, it must first separate its duplicated chromosomes and split its cytoplasm between them. This fundamentally important event, cytokinesis, must occur at the correct time, after chromosome segregation, and place, between the segregated chromosomes. In bacteria, cytokinesis is orchestrated by an essential and highly conserved tubulin-like protein, FtsZ, which assembles into a circumferential ring structure, called the Z-ring, on the inner membrane at the cell midpoint. Once assembled, the Z-ring of E. coli then recruits at least 10 additional essential division proteins to the membrane at the developing division site, after which the ring contracts at the leading edge of the growing septal wall to split the cell into two. Surprisingly, the molecular roles of most of these proteins in the functioning of the cell division machine are unknown. It is also unclear how the various proteins in the machine recruit and stabilize each other, or how the Z ring is triggered to contract once the machine is assembled. Our previous work has shown that some of these proteins can be eliminated with little cost by changing the activities of other proteins, indicating that the cell division machine may be overbuilt. We seek to understand the function of the proteins in the machine by distinguishing the core components from the regulatory components. Our approach utilizes genetics, protein biochemistry, and imaging of whole cells. Specifically, we propose to (i) understand how FtsZ assembly is regulated by cell division proteins such as the actin-like FtsA; (ii) define how FtsZ and FtsA recruit and build the rest of the machine via a cooperative network of protein-protein interactions; and (iii)strip down the rest of the machine to its core components using genetics. The study of bacterial cell division is important not only because it is a basic cellular process that needs to be understood, but also because cytokinesis is an important potential target of antimicrobials.

在任何细胞分裂以产生可行的女儿之前，它必须首先将其重复的染色体分开并分开 它们之间的细胞质。这一根本重要的事件必须以正确的状态发生。 时间，染色体分离和位置，在隔离的染色体之间。在细菌中， 细胞因子由必不可少且高度保守的小管蛋白样蛋白FTSZ策划，该蛋白会组装 在细胞中点的内膜上进入一个称为Z环的圆环结构。一次 组装后，大肠杆菌的Z环将至少招募至少10个其他必要分裂蛋白到该蛋白 开发部部门的膜，之后，戒指在生长的前沿收缩 隔壁壁将细胞分成两个。令人惊讶的是，大多数这些蛋白质在 细胞分裂机的功能尚不清楚。还不清楚各种蛋白质如何 机器招募和稳定彼此，或者在机器是一旦触发Z环的收缩方式 组装。我们以前的工作表明，其中一些蛋白质可以以几乎没有成本消除 改变其他蛋白质的活性，表明细胞分裂机可能过于建造。我们寻找 通过区分核心组件和 监管组件。我们的方法利用遗传学，蛋白质生物化学和整个细胞成像。 具体而言，我们建议（i）了解FTSZ组装如何受细胞分裂蛋白（例如 类似肌动蛋白的FTSA； （ii）定义FTSZ和FTSA如何通过合作招募和建造机器的其余部分 蛋白质蛋白质相互作用网络； （iii）将机器的其余部分剥离到其核心组件 使用遗传学。细菌细胞分裂的研究很重要，不仅是因为它是基本的细胞过程 这需要被理解，还因为细胞因子是抗菌剂的重要潜在靶标。