Assembly and Maintenance of the Bacterial Cell Envelope

项目总结 细胞膜位于细菌病原体和它们的宿主的交界处。它含有独特的分子， 是由先天免疫系统识别的，它是嵌入关键毒力因素的地方。单元格 包膜和构建它的生物发生途径也是我们许多最有效的抗生素和 疫苗疗法。由于细胞膜生物发生一直是一个如此成功的靶点，它一直是一个活跃的 半个多世纪以来的研究领域。大多数负责细胞合成和重塑的基因 人们已经鉴定了不同的表面聚合物，并表征了它们的生化活性。然而，a 我们知识中的主要差距是这些不同的通路是如何相互协调的，以及细胞是如何 监控信封是否有缺陷，并指导其修复。该提案的重点是调查 不同表面聚合物的合成和包膜修复之间的协调 模式革兰氏阳性细菌枯草芽孢杆菌。 革兰氏阳性细胞被膜由不同层次的表面聚合物组成，包括脂质连接的 阴离子聚合物称为脂磷壁酸(LTA)，多层细胞壁肽聚糖(PG)和不同的 附着在其上的阴离子聚合物称为壁磷壁酸(WTA)。细胞生长需要协调 这些包膜层的合成，但这种协调的机制仍然很差 明白了。第二个悬而未决的问题是革兰氏阳性细菌如何监控和修复其体内的缺陷 信封层。在前期工作中，我发现合成PG和PG的保守酶 在其上转移WTA含有细胞外固有无序区(IDR)。我的数据和之前的研究 我的宿主实验室认为，这些区域将合成酶引导到细胞壁网络中的间隙或缺陷，从而 加强他们的防御。这项提案的目标是：(1)确定革兰氏阳性细菌是如何监测和修复其 单元格包络层和(2)使用定向和公正的方法来研究 PG和磷壁酸的组装。 该项目将在大卫·鲁德纳博士的实验室中进行，微生物学系位于 哈佛医学院。我将得到鲁德纳博士的密切指导，并将嵌入一个丰富的和 致力于科学交流和发现的大学科学界。形成性训练和 我在奖学金期间建立的人脉将有助于我未来的职业生涯 独立研究调查员。

PROJECT SUMMARY The cell envelope lies at the interface of bacterial pathogens and their host. It contains unique molecules that are recognized by the innate immune system, and it is where key virulence factors are embedded. The cell envelope and the biogenesis pathways that build it are also targets of many of our most effective antibiotic and vaccine therapies. Because cell envelope biogenesis has been such a successful target, it has been an active area of research for over half a century. Most of the genes responsible for the synthesis and remodeling of the different surface polymers have been identified and their biochemical activities characterized. However, a major gap in our knowledge is how these different pathways are coordinated with each other and how the cell monitors the envelope for defects and directs their repair. This proposal focuses on investigating the coordination between the synthesis of the distinct surface polymers and the repair of the envelope using the model gram-positive bacterium Bacillus subtilis. The gram-positive cell envelope is composed of distinct layers of surface polymers including lipid-linked anionic polymers called lipoteichoic acids (LTAs), the multi-layered cell wall peptidoglycan (PG) and the distinct anionic polymers called wall teichoic acids (WTAs) that are attached to it. Cell growth requires the coordinated synthesis of these envelope layers, but the mechanisms underlying this coordination remain poorly understood. A second outstanding question is how gram-positive bacteria monitor and repair defects in their envelope layers. In preliminary work, I have discovered that conserved enzymes that synthesize PG and transfer WTA onto it contain extracellular intrinsically disorder regions (IDRs). My data and previous studies in my host lab suggest that these regions direct the synthases to gaps or defects in the cell wall meshwork to fortify them. The goals of this proposal are (1) to establish how gram-positive bacteria monitor and repair their cell envelope layers and (2) use directed and unbiased approaches to investigate the interplay between the assembly of the PG and the teichoic acids. This project will be carried out in the laboratory of Dr. David Rudner in the Department of Microbiology at Harvard Medical School. I will be closely mentored by Dr. Rudner and will be embedded within a rich and collegial scientific community committed to scientific exchange and discovery. The formative training and connections that I make during my fellowship will be instrumental in launching my future career as an independent research investigator.