The Bacterial Secretosome

细菌分泌体

• 批准号: BB/S008349/1
• 负责人: Ian Collinson
• 金额: $ 105.22万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FS008349%2F1
• 关键词: Bacterial; Secretosome

All cells are surrounded by membranes, made up from a double layer of fatty molecules called phospholipids. Cell membranes act as a molecular "skin", keeping the cell's insides in, and separating different biochemical reactions. The barrier needs to be breached in a controlled manner to allow transport of nutrients, waste products and for communication with the outside world; this is achieved by a wide range of membrane-inserted proteins. We understand a great deal about the diverse biological functions that membrane proteins bestow, such as transport, respiration, photosynthesis. However, we know very little about how membranes are formed, or about the necessary transport of proteins across or into membranes during their biogenesis.Our proposal aims to understand more about how the cell's protein secretion occurs. The secretory ('Sec' for short) machinery is essential for life - for every cell in every organism. The project concerns this process, in very simple bacterial cells. Bacteria secrete proteins for a wide range of membrane and extracellular activities including for: cell adherence, pathogenicity, the degradation of antibiotics, including also the biogenesis of the protective cell wall. A major class of bacteria known as Gram-negatives, possess a cell wall composed of a periplasm with a peptidoglycan (PG) layer, surrounded by an outer-membrane. The biogenesis of the cell wall is dependent on protein secretion through from the cell interior through the Sec machinery. Proteins of the periplasm can readily fold and remain there. Proteins are also transported across or into the outer membrane by another transport machine called the BAM complex, but it is not clear how they are shuttled there, to ensure the process is rapid and efficient.We have identified an interaction between the Sec machinery of the inner plasma membrane and the BAM complex, forming a structure that spans the entirety of the cell wall. This giant assembly, which we have called the bacterial 'secretosome', could form a contiguous conduit for very efficient passage of proteins from the cytosol to the outer-membrane. Its existence will have far reaching implications for our understanding of outer-membrane biogenesis.The project will harness complementary expertise in biochemistry and new breakthrough technologies in imaging by light and high-resolution electron cryo-microscopy. These scientific methods will illuminate the architecture of the secretosome, and how it works. The results of the project will be important because the bacterial cell wall, is vulnerable to attack. The weakening of the cell wall, or a compromise in its biogenesis or regenerative capabilities could be lethal. Therefore, new information towards our understanding of the bacterial secretosome, and its action in the maintenance of the cell wall, could suggest ways in which it could be subverted towards the development of new antibiotics. This would generate much needed ammunition in our fight against antimicrobial resistance (AMR).

所有的细胞都被膜所包围，膜由称为磷脂的双层脂肪分子组成。细胞膜就像一层分子的“皮肤”，把细胞的内部保持在里面，并把不同的生化反应分开。屏障需要以受控的方式被突破，以允许营养物质，废物的运输以及与外界的交流;这是通过各种膜插入蛋白质来实现的。我们对膜蛋白赋予的各种生物功能有了很大的了解，如运输、呼吸、光合作用。然而，我们对膜是如何形成的，或者对蛋白质在生物合成过程中穿过或进入膜的必要运输知之甚少。我们的建议旨在更多地了解细胞的蛋白质分泌是如何发生的。分泌（简称“Sec”）机制对于生命是必不可少的-对于每一个有机体中的每一个细胞。该项目涉及非常简单的细菌细胞中的这一过程。细菌分泌蛋白质用于广泛的膜和细胞外活性，包括：细胞粘附、致病性、抗生素降解，还包括保护性细胞壁的生物发生。被称为革兰氏阴性菌的主要种类具有由具有肽聚糖（PG）层的周质组成的细胞壁，所述周质被外膜包围。细胞壁的生物发生依赖于蛋白质从细胞内部通过Sec机制的分泌。周质的蛋白质可以很容易地折叠并保持在那里。蛋白质也通过另一种称为BAM复合物的运输机器运输穿过或进入外膜，但目前尚不清楚它们如何穿梭在那里，以确保该过程快速有效。我们已经确定了内质膜的Sec机器和BAM复合物之间的相互作用，形成了一种跨越整个细胞壁的结构。这个巨大的集合体，我们称之为细菌的“分泌体”，可以形成一个连续的管道，使蛋白质从胞质溶胶非常有效地传递到外膜。它的存在将对我们理解外膜生物发生产生深远的影响。该项目将利用生物化学方面的互补专业知识以及光学和高分辨率电子冷冻显微镜成像方面的新突破技术。这些科学方法将阐明分泌体的结构，以及它是如何工作的。该项目的结果将是重要的，因为细菌的细胞壁，是容易受到攻击。细胞壁的弱化，或其生物发生或再生能力的妥协可能是致命的。因此，我们对细菌分泌体及其在维持细胞壁中的作用的理解的新信息可能会建议它可以被颠覆以开发新抗生素的方法。这将为我们对抗抗菌素耐药性（AMR）提供急需的弹药。

项目成果

Inter-membrane association of the Sec and BAM translocons for bacterial outer-membrane biogenesis.

• DOI: 10.7554/elife.60669
• 发表时间: 2020-11-04
• 期刊: eLife
• 影响因子: 7.7
• 作者: Alvira S;Watkins DW;Troman L;Allen WJ;Lorriman JS;Degliesposti G;Cohen EJ;Beeby M;Daum B;Gold VA;Skehel JM;Collinson I
• 通讯作者: Collinson I

Refined measurement of SecA-driven protein transport reveals indirect coupling to ATP turnover

对 SecA 驱动的蛋白质转运的精确测量揭示了与 ATP 周转的间接耦合

• DOI: 10.1101/2020.05.08.084160
• 发表时间: 2020
• 作者: Allen W

Rate-limiting transport of positively charged arginine residues through the Sec-machinery is integral to the mechanism of protein secretion.

• DOI: 10.7554/elife.77586
• 发表时间: 2022-04-29
• 期刊: ELIFE
• 影响因子: 7.7
• 作者: Allen, William J.;Corey, Robin A.;Watkins, Daniel W.;Oliveira, A. Sofia F.;Hards, Kiel;Cook, Gregory M.;Collinson, Ian
• 通讯作者: Collinson, Ian

Pushing the Envelope: The Mysterious Journey Through the Bacterial Secretory Machinery, and Beyond.

• DOI: 10.3389/fmicb.2021.782900
• 发表时间: 2021
• 期刊: Frontiers in microbiology
• 影响因子: 5.2
• 作者: Troman LA;Collinson I
• 通讯作者: Collinson I

INTERACTION OF THE PERIPLASMIC CHAPERONE SURA WITH THE INNER MEMBRANE PROTEIN SECRETION (SEC) MACHINERY

周质伴侣 SURA 与内膜蛋白分泌 (SEC) 机器的相互作用

• DOI: 10.1101/2022.09.14.507990
• 发表时间: 2022
• 作者: Troman L