Biogenesis of Bordetella cell envelope components

博德特氏菌细胞包膜成分的生物发生

• 批准号: RGPIN-2016-05426
• 负责人: Fernandez, Rachel
• 金额: $ 2.77万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709685
• 关键词: Biogenesis; Bordetella; cell; envelope; components

The envelope of Gram negative bacteria is complex. It comprises the inner membrane and the cell wall. The cell wall consists of a thin peptidoglycan structure surrounded by an asymmetric outer membrane bilayer consisting of phospholipids and lipopolysaccharides within which are attached or embedded various (lipo)proteins. The space between the inner and outer membranes is called the periplasm. In addition to functioning as a selective barrier and protecting bacteria from harsh conditions, the envelope plays a critical role in determining the outcome of interactions between the bacterium and its environment. Indeed, several components of the cell envelope are regulated in response to environmental conditions. Furthermore, the biogenesis of envelope components is also complex; targeting envelope components to specific locations requires dedicated molecular machinery and mechanisms that maintain the components in a state suited to being able to traverse one or more membranes. These mechanisms may also assist in promoting the function of the components once they have reached their destination. This proposal addresses components comprising the envelope of Bordetella species. Many Bordetella species are human or animal pathogens and there is much to learn about how the Bordetella envelope is made. We will focus on two aspects of the Bordetella envelope the biogenesis of surface proteins called autotransporters and a system that modifies the lipid A portion of lipopolysaccharide. We will characterize how two novel autotransporters with distinct and non-typical structures are secreted past the outer membrane. We will ascertain the requirement for accessory factors, how these autotransporter proteins interact with accessory factors, the role of the autotransporter C-terminus in effecting secretion, and how the proteins fold on the bacterial surface following secretion. With respect to lipid A modification, we will characterize the mechanism of how a group of proteins function together to modify lipid A with glucosamine at the inner membrane of the cell envelope. This process is highly regulated and is predicted to involve several regulatory systems, including a putative anti-sense RNA. We will investigate how this system is coordinated. Understanding how the envelope is built, especially in non model organisms can lead to uncovering fundamental principles of how membranes and membrane proteins and lipids are made and can also lead to improved methods for cell surface display or manipulation that can be used in bio and nanotechnology applications.

革兰氏阴性菌的包膜是复杂的。它包括内膜和细胞壁。细胞壁由薄的肽聚糖结构组成，该结构被不对称的外膜双层包围，该外膜双层由磷脂和脂多糖组成，其中附着或嵌入各种（脂）蛋白。内外膜之间的空间称为周质。除了作为选择性屏障和保护细菌免受恶劣条件的影响外，包膜在决定细菌与其环境之间相互作用的结果方面起着关键作用。事实上，细胞被膜的几个组成部分是受环境条件调节的。此外，包膜组分的生物发生也是复杂的;将包膜组分靶向到特定位置需要专用的分子机器和机制，其将组分维持在适合于能够穿过一个或多个膜的状态。这些机制还可在部件到达目的地后协助促进部件的功能。 该提案涉及构成博德特氏菌属种包膜的组分。许多博德特氏菌属物种是人类或动物的病原体，关于博德特氏菌属的包膜是如何形成的，还有很多东西需要了解。我们将集中在两个方面的博德特氏菌包膜的生物起源的表面蛋白称为自动转运和系统，修改脂多糖的脂质A部分。我们将描述两种具有不同和非典型结构的新型自身转运蛋白是如何分泌通过外膜的。我们将确定辅助因子的要求，这些自转运蛋白如何与辅助因子相互作用，自转运蛋白C-末端在影响分泌中的作用，以及蛋白质如何在分泌后在细菌表面折叠。关于脂质A修饰，我们将描述一组蛋白质如何共同作用以在细胞包膜的内膜处用葡萄糖胺修饰脂质A的机制。这一过程受到高度调控，预计涉及几个调控系统，包括推定的反义RNA。我们将研究如何协调这个系统。 了解包膜是如何构建的，特别是在非模式生物中，可以揭示膜和膜蛋白和脂质是如何形成的基本原理，也可以改进细胞表面显示或操作的方法，这些方法可以用于生物和纳米技术应用。