Growth and differentiation in Bacillus subtilis

枯草芽孢杆菌的生长和分化

• 批准号: 10630235
• 负责人: DAVID Z RUDNER
• 金额: $ 63.04万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10630235
• 关键词: 3-Dimensional; ATP phosphohydrolase; Antibiotics; Bacillus subtilis; Bacteria; Biogenesis; Cell Wall; Cells; Cellular biology; Chromatin Loop; Chromosomes; Complex; Cytolysis; Cytoprotection; DNA; Defect; Differentiation and Growth; Disease; Ensure; Enzymes; Eukaryota; Failure; Goals; Growth; Human; Hydrolase; Knowledge; Link; Lipids; Maintenance; Malignant Neoplasms; Mediating; Molecular; Monitor; Morphology; Organism; Osmosis; Pathway interactions; Peptides; Peptidoglycan; Play; Polysaccharides; Process; Replication Origin; Research; Resolution; Role; Shapes; Signal Transduction; Signal Transduction Pathway; Sister; Sister Chromatid; Site; System; Therapeutic Intervention; Walking; chromosome replication; combat; condensin; crosslink; developmental disease; inorganic phosphate; insight; new therapeutic target; repaired; segregation; therapeutic development; virtual

PROJECT SUMMARY/ABSTRACT The proposed studies are part of our long-term effort to elucidate fundamental mechanisms underlying chromosome dynamics and bacterial envelope biogenesis in the bacterium Bacillus subtilis. Compaction of replicated chromosomes into morphologically and spatially distinct sister chromatids is essential for faithful DNA segregation in all organisms. The goal of our research is to broadly elucidate how B. subtilis organizes and segregates its chromosomes but we have placed particular emphasis on defining the activity and function of the broadly conserved SMC condensin complex in these processes. Our studies have revealed that these ring-shaped ATPases extrude DNA loops. Loop extrusion ensures that these complexes act in cis drawing DNA in on itself and away from its sister chromosome. This activity can explain how SMC complexes can resolve newly replicated origins in bacteria and sister chromatids in eukaryotes. Our future research seeks to establish whether loop extrusion mediates origin resolution and the extent to which it drives the dynamic rearrangements of the chromosome during the replication-segregation cycle. Separately, we will define the molecular basis for site-specific unloading of SMC complexes by XerD at the replication terminus. Analysis of chromosome dynamics in this simple bacterial system will provide mechanistic insight and a level of resolution not possible in more complex organisms. The bacterial cell wall peptidoglycan (PG) is composed of long glycan strands cross-linked together by short peptides. This three-dimensional meshwork protects the cell from osmotic lysis, determines shape, and its assembly is the target of some of our most successful antibiotics. Accordingly, a deeper understanding of cell wall biogenesis has broad implications for both basic bacterial cell biology and therapeutic development. Research over the last half century has identified virtually all the factors involved in envelope assembly. A major gap in our knowledge is how these enzymes are coordinated with each other and how the cell monitors the envelope for defects and directs their repair. Our future research is focused on three signal transduction pathways that play central roles in these processes. The WalR-WalK two-component signaling system is involved in the homeostatic control of cell wall hydrolases required for growth. The SigI-RsgI pathway monitors the cell wall meshwork and induces PG remodeling enzymes when it identifies defects. Finally, the SigM-YhdLK pathway monitors the universal lipid carrier undecaprenyl-phosphate and prioritizes its use for cell wall synthesis. We seek to define how these pathways function in molecular detail. Our findings will provide broadly relevant principles for envelope assembly and maintenance in all bacteria.

项目概要/摘要 拟议的研究是我们长期努力的一部分，旨在阐明潜在的基本机制 枯草芽孢杆菌的染色体动力学和细菌包膜生物发生。 将复制的染色体压缩成形态和空间上不同的姐妹染色单体是 对于所有生物体中 DNA 的忠实分离至关重要。我们研究的目标是广泛阐明 B. 枯草芽孢杆菌组织并分离其染色体，但我们特别强调定义 广泛保守的 SMC 凝缩蛋白复合物在这些过程中的活性和功能。我们的研究有 研究表明，这些环状 ATP 酶会挤出 DNA 环。环挤出确保这些复合物 以顺式作用，将 DNA 拉入自身并远离其姐妹染色体。此活动可以解释 SMC 如何 复合物可以解析细菌中新复制的起源和真核生物中的姐妹染色单体。我们的未来 研究旨在确定环挤出是否介导起源解析及其驱动程度 复制分离周期中染色体的动态重排。我们将分别 定义了 XerD 在复制末端对 SMC 复合物进行位点特异性卸载的分子基础。 对这个简单细菌系统中染色体动力学的分析将提供机制洞察和水平 在更复杂的生物体中不可能实现这种分辨率。 细菌细胞壁肽聚糖（PG）由短聚糖交联在一起的长聚糖链组成。 肽。这种三维网络保护细胞免遭渗透裂解、决定形状及其 组装是我们一些最成功的抗生素的目标。因此，对细胞有更深入的了解 壁生物发生对于基本细菌细胞生物学和治疗开发具有广泛的影响。 过去半个世纪的研究几乎已经确定了信封组装中涉及的所有因素。一个 我们知识的主要差距是这些酶如何相互协调以及细胞如何监测 信封是否有缺陷并指导其修复。我们未来的研究重点是三种信号转导 在这些过程中发挥核心作用的途径。 WalR-WalK 双组件信号系统是 参与生长所需的细胞壁水解酶的稳态控制。 SigI-RsgI 通路 监测细胞壁网络并在识别缺陷时诱导 PG 重塑酶。最后， SigM-YhdLK 通路监测通用脂质载体十一异戊二烯基磷酸盐并优先考虑其使用 细胞壁合成。我们试图在分子细节上定义这些途径如何发挥作用。我们的研究结果将 为所有细菌的包膜组装和维护提供广泛相关的原理。

项目成果

The DedA superfamily member PetA is required for the transbilayer distribution of phosphatidylethanolamine in bacterial membranes.

• DOI: 10.1073/pnas.2301979120
• 发表时间: 2023-05-16
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Roney, Ian J.;Rudner, David Z.
• 通讯作者: Rudner, David Z.

Bacterial SEAL domains undergo autoproteolysis and function in regulated intramembrane proteolysis.

细菌 SEAL 结构域经历自身蛋白水解并在调节的膜内蛋白水解中发挥作用。

• DOI: 10.1101/2023.06.27.546760
• 发表时间: 2023
• 期刊: bioRxiv : the preprint server for biology
• 作者: Brogan,AnnaP;Habib,Cameron;Hobbs,SamuelJ;Kranzusch,PhilipJ;Rudner,DavidZ
• 通讯作者: Rudner,DavidZ