Probing the molecular interactions and architecture of bacterial cell division proteins

细胞微生物学在过去的几年里出现了复兴，部分原因是成像技术的进步。我们能够窥视细胞，看到参与基本过程的大分子复合物的定位和组织，这推进了我们对细菌如何移动，关联和分裂的理解。在革兰氏阴性细菌中，一组称为分裂体的蛋白质驱动内膜和外膜的同步内陷以及新形成的隔膜处的肽聚糖合成。分裂体蛋白形成多组分Z环结构，其主要由微管蛋白同源物FtsZ组成。FtsZ长丝形成的动力学被认为是必要的适当的Z-环组装。在大肠杆菌中，约10种必需蛋白和超过20种非必需蛋白参与分裂体组装。相互作用以分层的方式发生，所提出的细胞分裂机制可以分为三个不同的阶段-早期，中期和晚期。虽然细菌细胞分裂已经在细胞和分子水平上深入研究了几十年，确定了许多关键蛋白质参与者，但关于控制分裂体形成和动力学的分子机制和蛋白质相互作用的关键问题仍然存在。* 本研究项目旨在阐明Z环稳定性和动力学中涉及的蛋白质相互作用和大分子结构。具体来说，我们将确定和表征的相互作用和大分子结构的FtsZ和Zap家族的蛋白质。这些相互作用对早期细胞分裂至关重要，Zap蛋白的重叠功能与Z环介导的分隔有关。我们还将确定蛋白质的相互作用，在中期阶段的细胞分裂，管理如何FtsK，一个必不可少的细胞分裂的“检查点”蛋白，连接分裂的细胞质与分隔和细胞壁内陷。我们将使用生物化学，分子和尖端成像工具的原始组合来解决这些问题，这将导致细胞分裂的突破性进展。该研究计划的长期愿景是在其所有不同阶段开发细菌细胞分裂的完整生物化学和结构图，从而阐明驱动这一重要过程的机制。我们的发现和我们开发的方法将超越原核细胞生物学，并将适用于不同的生物系统。

Cellular microbiology has seen a renaissance in the past several years, spurred in part by advances in imaging techniques. Our ability to peer into cells to see the localization and organization of macromolecular complexes involved in fundamental processes has advanced our understanding of how bacteria move, associate and divide. In gram-negative bacteria, a group of proteins known as the divisome drives the synchronized invagination of the inner and outer membranes and peptidoglycan synthesis at the newly formed septum. Divisome proteins form the multicomponent Z-ring structure, which is primarily composed of the tubulin homologue FtsZ. The dynamics of FtsZ filament formation are considered essential for proper Z-ring assembly. In Escherichia coli, ~10 essential and over 20 nonessential proteins are involved in divisome assembly. Interactions occur in a hierarchical manner, and the proposed mechanisms of cell division can be divided into three distinct stages - early, intermediate and late. Although bacterial cell division has been intensively studied at the cellular and molecular levels for decades, with many of the key protein players identified, critical questions remain about the molecular mechanisms and protein interactions that govern the formation and dynamics of the divisome. ***This research program aims to elucidate the protein interactions and macromolecular structures involved in Z-ring stability and dynamics. Specifically, we will identify and characterize the interactions and macromolecular architecture of FtsZ and the Zap family of proteins. These interactions are critical for early-stage cell division, and the overlapping functions of the Zap proteins have been implicated in Z-ring-mediated septation. We will also determine the protein interactions in intermediate-stage cell division that govern how FtsK, an essential cell division `checkpoint' protein, links division of the cytoplasm with septation and cell wall invagination. We will address these questions using an original combination of biochemical, molecular and cutting-edge imaging tools, which will lead to groundbreaking advances in cell division. The long-term vision for this research program is to develop a complete biochemical and structural picture of bacterial cell division during all of its distinct stages, thereby elucidating the mechanisms that drive this essential process. Our findings and the approaches we develop will transcend prokaryotic cell biology and will be applicable to diverse biological systems.**