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).

所有细胞都被膜包围，由称为磷脂的双层脂肪分子组成。细胞膜充当分子“皮肤”，使细胞的内部内部保持并分离不同的生化反应。需要以受控的方式破坏障碍，以允许营养物质，废物产品运输以及与外界的沟通；这是通过各种膜插入蛋白来实现的。我们对膜蛋白赋予的多种生物学功能（例如运输，呼吸，光合作用）的多种生物学功能了解很多。但是，我们对膜的形成是如何形成的，或者在其生物发生过程中跨膜跨膜的必要运输。我们的建议旨在更多地了解细胞的蛋白质分泌。分泌（简称为“ SEC”）机械对生命至关重要 - 对于每个生物体中的每个细胞。该项目在非常简单的细菌细胞中涉及该过程。细菌分泌多种膜和细胞外活性的蛋白质，包括：细胞依从性，致病性，抗生素的降解，包括保护性细胞壁的生物发生。一类称为革兰氏阴性菌的细菌具有由肽聚糖（PG）层组成的细胞壁，被外膜包围。细胞壁的生物发生取决于从细胞内部到SEC机械的蛋白质分泌。周质的蛋白质很容易折叠并留在那里。蛋白质还通过另一台称为BAM复合物的运输机跨或进入外膜，但尚不清楚它们是如何穿梭的，以确保过程快速有效。我们已经确定了内部质膜的SEC机械与BAM复合物之间的相互作用，形成了整个细胞壁的结构。我们称之为细菌“秘密体”的巨型组件可以形成连续的导管，以非常有效地通过蛋白质从胞质溶胶转移到外膜。它的存在将对我们对外膜生物发生的理解具有很大的影响。该项目将通过光和高分辨率电子冷冻微镜检查来利用生物化学的互补专业知识，并在成像中进行新的突破性技术。这些科学方法将阐明秘密体的结构及其工作原理。该项目的结果将很重要，因为细菌细胞壁很容易受到攻击。细胞壁的弱化或其生物发生或再生能力的折衷可能是致命的。因此，有关我们对细菌秘密体的理解的新信息及其在维持细胞壁中的作用，可以提出可以颠覆新抗生素发展的方法。这将在我们反对抗菌抗性（AMR）的战斗中产生急需的弹药。

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

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

• DOI: 10.1101/589077
• 发表时间: 2020-01-01
• 期刊: bioRxiv
• 作者: Alvira, S.;Watkins, DW.;Collinson, I.
• 通讯作者: Collinson, I.

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

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