Communicating across the membrane during bacterial cell division

细菌细胞分裂过程中的跨膜通讯

• 批准号: 1813801
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1813801
• 关键词: Communicating; across; membrane; during; bacterial

The activities of various processes are co-ordinated during bacterial cell division. For instance, the constriction of the division septum is linked to new cell wall synthesis at the division site, which is necessary to stop the cell from bursting due to turgor. Moreover, the proteins of the contractile ring at the division site are cytosolic, yet the enzymes that perform the final, essential polymerising steps in cell wall biosynthesis are found on the outside face of the plasma membrane. Essential activities thus have to be co-ordinated across the membrane, and there is currently a dearth of information on how this takes place. The formation of the cell wall is essential for bacteria, and this process is the target of antibiotics such as penicillin and vancomycin. While antimicrobial resistance continues to rise, it is pertinent to re-evaulate cell wall synthesis as a target for the generation of novel antibiotics.We will examine how cell division regulators affect cell wall synthesis, and determine the molecular mechanisms underpinning the regulation. For instance, we are interested in how EzrA, a regulator of septal contraction, is linked to cell wall synthesis. By two hybrid analyses, it is known that EzrA interacts with both PBP1, a key peptidoglycan synthase, and FtsZ, the bacterial homolog of tubulin, which drives septal contraction. EzrA thus links cytokinetic events on the inside of the cell to peptidoglycan synthesis on the outside, but it is not known how EzrA fulfils its communication role. We have recently solved the crystal structure of EzrA, revealing that it resembles the spectrin family of eukaryotic cytoskeletal proteins. We are also interested in how an unrelated cell division regulator, GpsB, appears to co-ordinate the shuttling of peptidoglycan synthases from the lateral walls of the cell during cell growth, to the division site during cytokinesis. We have solved crystal structures of the individual domains of GpsB, and have used SAXS to generate a model of full-length GpsB. We will use the novel structural information and our well-established biochemical procedures to assess the impact of EzrA, GpsB and other regulators (e.g. PBP3, FtsZ, FtsA) on PBP1 function. The student will focus on trans-membrane communication: how a bacterium co-ordinates processes on both sides of the membrane during division is poorly understood, yet it is essential for the healthy cell. One process that requires such co-ordination, peptidoglycan synthesis, is the target of many overused antibiotics. The strategic importance of the project to the BBSRC is highlighted by the UK government's five year Antimicrobial Resistance Strategy 2013 to 2018. The studentship will underpin the development of novel antimicrobials and alternatives to antimicrobials. The student will receive training in core bioscience skills, and in biochemistry (enzymology) and in biophysics that require rigorous mathematical analysis and understanding of the data (e.g. MST, SPR, ITC, SEC-MALLS), and the student will apply these techniques to the problem of how bacteria build their outer defensive envelopes and how the synthesis of these envelopes is targeted by antimicrobials.

在细菌细胞分裂期间，各种过程的活动是协调的。例如，分裂隔膜的收缩与分裂部位的新细胞壁合成有关，这是阻止细胞因膨压而破裂所必需的。此外，在分裂位点处的收缩环的蛋白质是胞质的，然而在细胞壁生物合成中执行最后的、必要的聚合步骤的酶被发现在质膜的外表面上。因此，基本的活动必须在整个膜上进行协调，目前缺乏关于这是如何发生的信息。细胞壁的形成对细菌至关重要，这一过程是青霉素和万古霉素等抗生素的目标。随着抗生素耐药性的持续上升，重新评估细胞壁合成作为新抗生素产生的靶点是有意义的。我们将研究细胞分裂调节剂如何影响细胞壁合成，并确定支持这种调节的分子机制。例如，我们感兴趣的是EzrA，一个调节间隔收缩，是如何连接到细胞壁合成。通过两个杂交分析，已知EzrA与PBP 1（一种关键的肽聚糖合酶）和FtsZ（驱动隔膜收缩的微管蛋白的细菌同系物）两者相互作用。因此，EzrA将细胞内部的细胞动力学事件与外部的肽聚糖合成联系起来，但目前尚不清楚EzrA如何发挥其通信作用。我们最近解决了EzrA的晶体结构，揭示了它类似于真核细胞骨架蛋白的血影蛋白家族。我们也有兴趣在一个无关的细胞分裂调节，GPSB，似乎协调穿梭的肽聚糖酶从细胞的侧壁在细胞生长过程中，分裂的网站在胞质分裂。我们已经解决了GpsB的各个域的晶体结构，并使用SAXS生成全长GpsB的模型。我们将使用新的结构信息和我们完善的生化程序来评估EzrA，GpsB和其他调节剂（例如PBP 3，FtsZ，FtsA）对PBP 1功能的影响。学生将专注于跨膜通信：细菌在分裂过程中如何协调膜两侧的过程尚不清楚，但它对健康细胞至关重要。其中一个需要这种协调的过程，肽聚糖合成，是许多过度使用的抗生素的目标。该项目对BBSRC的战略重要性在英国政府2013年至2018年的五年抗菌素耐药性战略中得到了强调。该奖学金将支持新型抗菌剂和抗菌剂替代品的开发。学生将接受核心生物科学技能，生物化学（酶学）和生物物理学方面的培训，这些培训需要严格的数学分析和对数据的理解（例如MST，SPR，ITC，SEC-MALLS），学生将把这些技术应用于细菌如何构建其外部防御包膜以及这些包膜的合成如何被抗菌剂靶向的问题。