Mechanisms and Regulation of Cell Division in Bacteria

项目总结 蜂窝就像一座城市，有组织但充满活力的基础设施被分成不同的专业。对于 在过去的25年里，我的实验室研究了最简单的细胞--细菌--是如何自我组织和 分裂以产生后代细胞。我们主要关注细菌(如大肠杆菌)如何实现 在合适的时间将自己一分为二的艰巨任务(一旦他们的遗传物质 复制)，并每隔20分钟放置一次(正好在中间)，不出错。通向 这种成功是肌动蛋白聚合体(FTSA)和微管蛋白的古老而通用的版本 (FtsZ)，20多年前，我们的实验室首次在活细菌中观察到了它。今天，我们使用 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 对这些细胞骨架聚合物及其相关蛋白质的调控，这些蛋白质组成了 分离细菌细胞的动态膜相关蛋白纳米机器(分裂体)。 这在一定程度上要归功于我们对必需分裂体蛋白的旁路抑制因子的描述。 现在变得很清楚，分区是高度灵活的，并且可以根据 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，但仍有许多需要 了解整体分区结构、各部分的互换性以及如何进行改造 对时间和环境的提示做出反应。我们将通过以下方式解决这些基本问题 (1)通过以下方式获得更多关于胞质分裂过程中蛋白质-蛋白质接触的高分辨率信息 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，用超分辨显微镜观察 全细胞和重组仿生蛋白-膜系统；(3)利用 从其他模式细菌物种的分裂体蛋白质的多样性来区分常见的 和专门的机制；(4)了解分割组和其他 大规模细胞过程，如细胞壁生物合成。我们将通过以下方式利用这些方法 继续我们与几位亲密同事的合作，他们有互补的 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 对整个细胞如何运作和繁殖的前所未有的了解。拥有一个准确的 该城市单元的动态基础设施地图将允许对其工作方式进行预测， 以及如何打乱它。

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.