Cellular organization, division, and differentiation in an ancient, genetically reduced bacterium

一种古老的基因减少细菌的细胞组织、分裂和分化

• 批准号: 10621325
• 负责人: GEORGE WARREN LIECHTI
• 金额: $ 33.86万
• 依托单位: HENRY M. JACKSON FDN FOR THE ADV MIL/MED
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10621325
• 关键词: Address; Anabolism; Area; Bacteria; Cell Differentiation process; Cell Shape; Cell Size; Cell Wall; Cell division; Cell physiology; Cells; Cellular Stress; Chlamydia; Chlamydiaceae; Complex; Development; Elements; Environment; Exhibits; Five-Year Plans; Genome; Investigation; Knowledge; Life; Metabolic; Microbe; Modeling; Molecular; Molecular Machines; Organism; Osmosis; Peptidoglycan; Physiological Processes; Process; Role; Series; Stress; System; Work; member; model organism; response

Project Summary / Abstract In this proposal we aim to define the molecular mechanisms of division and differentiation in a phylum that consists entirely of bacterial species that live in osmotically stable, intracellular environments. During adaptation to intracellular life, microbes often exhibit a significant reduction in their genome size, resulting in the loss of metabolic and structural elements that are not required for life within a host cell. The bacterial cell wall, composed of peptidoglycan, protects most bacterial species from osmotic stress and is essential for cell division. Peptidoglycan also determines a bacterial cell’s shape, and by directing its synthesis and degradation microbes can effectively control cell size and differentiation between developmental forms. Nascent peptidoglycan biosynthesis is spatially and temporally restricted within bacterial cells via two known molecular complexes: the MreB complex, which is primarily associated with bacterial cell wall synthesis, and the FtsZ complex, which is associated with septal peptidoglycan synthesis required during cell division. Members of the Chlamydiae do not encode FtsZ and have long been thought to completely lack peptidoglycan. We recently discovered that several members of the Chlamydiaceae synthesize peptidoglycan but do not use it to form a canonical cell wall. Instead, these microbes utilize only septal peptidoglycan in their replicative forms, which is maintained, paradoxically, by an MreB complex. Here we propose a series of studies to investigate how members of the Chlamydiaceae temporally and spatially restrict peptidoglycan synthesis throughout the division process, efficiently controlling cell size, division, and the transition between developmental forms. Over the next five years we plan to increase our understanding of these fundamental processes by focusing on three major areas of investigation: 1) Identifying the mechanisms that direct and influence peptidoglycan synthesis and degradation in the absence of FtsZ, 2) characterizing polar localizing features present in Chlamydia and assessing their role in orienting peptidoglycan and the cell division complex, and 3) establishing the critical factors that influence bacterial cell size in an osmotically stable environment during the course of normal development and in response to cell stress. Genetically reduced microbes are attractive models for identifying the fundamental components of essential physiological processes. These planned studies will elucidate not only how genetically reduced microbes regulate cell size and divide in osmotically stable environments, but also illuminate the inherent versatility of the broadly conserved molecular complexes underlying these process.

项目摘要 /摘要 在此提案中，我们旨在定义划分和分化的分子机制 完全由生活在渗透稳定的细胞内环境中的细菌物种组成。期间 适应细胞内寿命，微生物通常表现出其基因组大小的显着降低，从而导致 宿主细胞中生命不需要的代谢和结构元素的丧失。细菌细胞 由胡椒聚糖组成的墙保护大多数细菌免受渗透胁迫，对细胞至关重要 分配。肽聚糖还确定细菌细胞的形状，并通过指导其合成和降解 微生物可以有效控制细胞大小和发育形式之间的区分。新生 肽聚糖的生物合成在细菌细胞中通过两个已知的分子在细菌细胞中受到临时限制 复合物：MREB复合物，主要与细菌细胞壁合成和FTSZ有关 复合物，与细胞分裂过程中需要的间隔辣椒合成有关。成员 衣原体不会编码FTSZ，长期以来一直认为完全缺乏petidoglycan。我们最近 发现衣原体科的几名成员合成了辣椒粉，但不要使用它来形成 规范细胞壁。取而代 通过MREB复合物矛盾地维持。在这里，我们提出了一系列研究，以研究如何 衣原体科的成员在整个过程中暂时和空间限制了辣椒糖的合成 分裂过程，有效控制细胞大小，分裂以及发育形式之间的过渡。 在接下来的五年中，我们计划通过重点关注这些基本过程的理解 投资的三个主要领域：1）识别直接和影响辣椒的机制 在没有FTSZ的情况下，合成和降解，2）表征存在于极性本地化特征 衣原体并评估它们在定位胡椒糖和细胞分裂综合体中的作用，以及3） 建立在渗透稳定环境中影响细菌细胞大小的关键因素 正常发育的过程和对细胞应激的反应。遗传减少的微生物很有吸引力 识别基本生理过程的基本组成部分的模型。这些计划 研究不仅会阐明微生物如何调节细胞大小并在渗透中分裂 稳定的环境，但也阐明了广泛保守的分子复合物的继承多功能性 这些过程的基础。

项目成果

Localized Peptidoglycan Biosynthesis in Chlamydia trachomatis Conforms to the Polarized Division and Cell Size Reduction Developmental Models.

• DOI: 10.3389/fmicb.2021.733850
• 发表时间: 2021
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Liechti GW

ZapG (YhcB/DUF1043), a novel cell division protein in gamma-proteobacteria linking the Z-ring to septal peptidoglycan synthesis.

• DOI: 10.1016/j.jbc.2021.100700
• 发表时间: 2021-01
• 期刊: The Journal of biological chemistry
• 作者: Mehla J;Liechti G;Morgenstein RM;Caufield JH;Hosseinnia A;Gagarinova A;Phanse S;Goodacre N;Brockett M;Sakhawalkar N;Babu M;Xiao R;Montelione GT;Vorobiev S;den Blaauwen T;Hunt JF;Uetz P
• 通讯作者: Uetz P