Mechanisms and Regulation of Cell Division in Bacteria

项目摘要 一个细胞就像一个城市，有一个有组织但动态的基础设施，分为专业。为 在过去的25年里，我的实验室一直在研究最简单的细胞--细菌--是如何组织自己的， 分裂产生后代细胞。我们主要集中在如何细菌，如E。大肠杆菌实现 在正确的时间把自己一分为二的艰巨任务（一旦他们的遗传物质被 重复），每20分钟放置一次（正好在中间），不要出错。的钥匙 这种成功是肌动蛋白（FtsA）和微管蛋白的蛋白质聚合物的古老和普遍的版本 （FtsZ），我们的实验室在20多年前首次在活细菌中观察到。今天我们用 最先进的超分辨率成像，结合分子遗传学，蛋白质生物化学， 相互作用研究和体外重建，以获得更详细的结构和 调节这些细胞骨架聚合物及其相关蛋白质，这些蛋白质包括 分裂细菌细胞的动态膜相关蛋白纳米机器（divisome）。 部分归功于我们对必需分裂体蛋白旁路抑制因子的表征， 现在越来越清楚的是，分裂体是高度灵活的，可以重塑自己，以回应 各种输入和扰动。尽管许多实验室做出了令人印象深刻的贡献， 了解整体的可分割结构，其部分的可分割性，以及它如何重塑 对时间和环境线索的反应。我们将通过以下方式解决这些基本问题： (1)通过以下方式获得关于胞质分裂期间蛋白质-蛋白质接触的更多高分辨率信息： 结合生物物理学，细胞学和遗传学方法;（2）研究寡聚体的作用， FtsZ和FtsA在分裂功能和调节中的状态，使用超分辨率显微镜， 全细胞和重组仿生蛋白-膜系统;（3）利用 来自其他模式细菌物种的分裂体蛋白的多样性，以区分常见的 （4）了解分裂与其他分裂之间的相互作用。 大规模的细胞过程，如细胞壁生物合成。我们将利用这些方法， 继续我们的合作与几个亲密的同事谁有互补 跨学科的专业知识。 我们正在进行的关于最简单的细胞如何分裂的研究应该为我们的研究铺平道路。 对整个细胞如何运作和繁殖的前所未有的理解。具有精确 绘制城市单元动态基础设施地图将有助于预测其工作方式， 以及如何破坏它。

Project summary A cell is like a city, with an organized yet dynamic infrastructure grouped into specialties. For the last 25 years, my lab has investigated how the simplest cells—bacteria—organize themselves and divide to make progeny cells. We mainly focus on how bacteria such as E. coli achieve the daunting task of splitting themselves in two at just the right time (once their genetic material is duplicated) and place (exactly in the middle) every 20 minutes without making errors. The keys to this success are ancient and universal versions of protein polymers of actin (FtsA) and tubulin (FtsZ), which our lab visualized for the first time in living bacteria over 20 years ago. Today, we use state of the art super-resolution imaging, combined with molecular genetics, protein biochemistry, interaction studies, and in vitro reconstitution, to gain more detailed insights into the structure and regulation of these cytoskeletal polymers and their associated proteins, which comprise the dynamic membrane-associated protein nanomachine (divisome) that divides bacterial cells. Thanks in part to our characterization of bypass suppressors of essential divisome proteins, it is now becoming clear that the divisome is highly flexible, and can remodel itself in response to various inputs and perturbations. Despite impressive contributions by many labs, there is much to be learned about overall divisome structure, the interchangeability of its parts, and how it remodels in response to temporal and environmental cues. We will address these fundamental questions by (1) obtaining more high-resolution information about protein-protein contacts during cytokinesis by combining biophysical, cytological, and genetic approaches; (2) investigating the role of oligomeric state of FtsZ and FtsA in divisome function and regulation, using super-resolution microscopy of whole cells and reconstituted biomimetic protein-membrane systems; (3) taking advantage of the diversity of divisome proteins from other model bacterial species to distinguish between common and specialized mechanisms; (4) understanding the interplay between the divisome and other large-scale cellular processes such as cell wall biosynthesis. We will leverage these approaches by continuing our collaborations with several close colleagues who have complementary interdisciplinary expertise. Our ongoing investigation of how the simplest cells divide should pave the way for an unprecedented understanding of how an entire cell functions and reproduces. Having an accurate map of that city-cell's dynamic infrastructure will allow predictions to be made about how it works, and how to disrupt it.