Targeting and assembly of E. coli cell division proteins

在任何细胞分裂产生可存活的子细胞之前，它必须首先分离其复制的染色体并分裂 它们之间的细胞质。这一根本性的重要事件，胞质分裂，必须发生在正确的位置。 时间，染色体分离后，和地点，分离的染色体之间。在细菌中， 胞质分裂是由一个重要的和高度保守的微管蛋白样蛋白，FtsZ，组装， 在细胞中点的内膜上形成一个环形结构，称为Z环。一旦 组装后，E.然后，大肠杆菌招募至少10种额外的必需分裂蛋白质， 膜在发展分裂网站，之后，环合同在前沿的增长 隔膜壁将细胞一分为二。令人惊讶的是，这些蛋白质中的大多数的分子作用， 细胞分裂机器的功能是未知的。目前还不清楚， 机器招募和稳定对方，或如何Z环被触发收缩，一旦机器是 组装好了我们以前的工作已经表明，这些蛋白质中的一些可以通过以下方式以很小的成本消除： 改变其他蛋白质的活性，表明细胞分裂机器可能过度构建。我们寻求 通过区分核心组件和蛋白质， 监管成分。我们的方法利用遗传学、蛋白质生物化学和全细胞成像。 具体来说，我们建议（i）了解FtsZ组装是如何由细胞分裂蛋白，如 肌动蛋白样FtsA;（ii）定义FtsZ和FtsA如何通过合作社招募和构建机器的其余部分 蛋白质-蛋白质相互作用的网络;以及（iii）将机器的其余部分剥离到其核心组件 利用遗传学。细菌细胞分裂的研究之所以重要，不仅因为它是一个基本的细胞过程 这一点需要理解，但也是因为胞质分裂是抗菌剂的一个重要潜在靶点。

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.