Assembly and Maintenance of the Bacterial Cell Envelope

项目摘要 细胞被膜位于细菌病原体与其宿主的界面处。它含有独特的分子， 是由先天免疫系统识别的，它是关键毒力因子嵌入的地方。细胞 包膜和构建它的生物合成途径也是我们许多最有效的抗生素的靶点， 疫苗疗法由于细胞被膜的生物发生是一个成功的靶点， 半个多世纪的研究领域。大多数负责合成和重塑细胞的基因 已经鉴定了不同的表面聚合物并表征了它们的生物化学活性。但 我们知识的一个主要空白是这些不同的途径是如何相互协调的，以及细胞是如何 监控信封的缺陷并指导其修复。该提案的重点是调查 不同表面聚合物的合成与使用表面聚合物修复包膜之间的协调。 模式革兰氏阳性菌枯草芽孢杆菌。 革兰氏阳性细胞被膜由不同的表面聚合物层组成， 称为脂磷壁酸（LTA）的阴离子聚合物、多层细胞壁肽聚糖（PG）和不同的 被称为壁磷壁酸（WTA）的阴离子聚合物附着于其上。细胞生长需要协调的 这些信封层的合成，但这种协调的机制仍然很差 明白第二个悬而未决的问题是，革兰氏阳性菌如何监测和修复它们的缺陷。 信封层。在初步工作中，我发现合成PG和 将WTA转移到含有细胞外固有无序区（IDR）的细胞上。我的数据和以前的研究， 我所在的实验室认为，这些区域可以将蛋白酶引导到细胞壁网络的缝隙或缺陷处， 加强他们。本提案的目标是（1）建立革兰氏阳性菌如何监测和修复其 细胞包膜层和（2）使用定向和无偏的方法来调查之间的相互作用， PG和磷壁酸的组装。 该项目将在微生物学系的大卫鲁弗斯博士的实验室进行， 哈佛医学院。我将密切指导博士鲁弗斯，并将嵌入在一个丰富的， 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联系将有助于我未来的职业生涯， 独立调查员。

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.