Establishing the Thermodynamic and Kinetic Thresholds for Bacterial Protein Secretion via the Type 3 Secretion System

通过 3 型分泌系统建立细菌蛋白分泌的热力学和动力学阈值

• 批准号: 0641582
• 负责人: Linda Nicholson
• 金额: $ 51.33万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0641582&HistoricalAwards=false
• 关键词: Establishing; Thermodynamic; Kinetic; Thresholds; Bacterial

Although the delivery of bacterial effector proteins into the cytoplasm of a host cell is a fundamental mechanism in pathogen infection, little is presently known regarding the detailed workings of the widely conserved type 3 secretion system (TTSS). Gaining an in-depth understanding of the molecular mechanisms employed by bacteria to deliver specific proteins at the right time and the right place will provide fundamental insights into the engineering of proteins for bacterial delivery and for developing novel strategies for disrupting pathogen infection. The main objectives of this project are addressed in the following questions: How are proteins able to be injected in a functional form into the host after having been requisitely unfolded in order to navigate the narrow lumen of the needle-like protrusion of the TTSS? What are the fundamental requirements that a given protein must meet in order to be successfully translocated from a bacterial pathogen into the host cytoplasm? This project employs fluorescence and NMR spectroscopies to investigate relationships between intracellular bacterial pH and the intrinsic folding equilibrium of effector proteins, with the overall goal of establishing the thermodynamic and kinetic parameters that facilitate coordinated effector delivery into the host cell. The outcomes of this research project should provide fundamental insights into how novel proteins might be engineered for bacterial delivery into host targets, and for developing novel strategies for disrupting a major mechanism of pathogen infection. The results of this project will help fill a large gap in our understanding of how bacteria deliver proteins to host cells. Results will be broadly disseminated through journal publications, the PIs Web page, and presentations at major meetings. The PI also teaches a large Proteins course (BioBM 631) in which current research results are incorporated. This project will strengthen networks with the Cornell plant pathology labs of Alan Collmer and Greg Martin, and provide training for graduate and undergraduate students in a highly interactive research environment that connects the disparate fields of plant biology, microbiology, biophysics, and protein NMR spectroscopy. Recent participation of an underrepresented minority Leadership Alliance student in the PIs lab will assist in future recruitment within this target population. The PI is also a Mentor for Assistant Professor Barbara Lyons in the INBRE program at New Mexico State University (NMSU), a Minority Serving Institution. Through the Leadership Alliance and INBRE programs, this project will provide research opportunities for and mentorship of underrepresented minority students in science.

尽管细菌效应蛋白向宿主细胞的细胞质中的递送是病原体感染中的基本机制，但是目前关于广泛保守的3型分泌系统（TTSS）的详细工作机制知之甚少。 深入了解细菌在正确的时间和正确的地点递送特定蛋白质所采用的分子机制，将为细菌递送蛋白质的工程设计和开发破坏病原体感染的新策略提供基本见解。 本项目的主要目标是解决以下问题：蛋白质如何能够被注射到主机的功能形式后，必须展开，以导航狭窄的管腔的针状突起的TTSS？ 一个特定的蛋白质要成功地从细菌病原体转移到宿主细胞质中，必须满足哪些基本要求？ 该项目采用荧光和NMR光谱研究细胞内细菌pH值和效应蛋白的内在折叠平衡之间的关系，总体目标是建立热力学和动力学参数，促进协调效应传递到宿主细胞。 该研究项目的结果应该提供关于如何将新型蛋白质工程化以将细菌递送到宿主靶点的基本见解，以及开发用于破坏病原体感染的主要机制的新策略。 该项目的结果将有助于填补我们对细菌如何将蛋白质递送到宿主细胞的理解中的一个巨大空白。研究结果将通过期刊出版物、PI网页和在主要会议上的演讲广泛传播。 PI还教授了一个大型蛋白质课程（BioBM 631），其中包含了当前的研究成果。 该项目将加强与Alan Collmer和Greg Martin的康奈尔植物病理学实验室的网络，并在高度互动的研究环境中为研究生和本科生提供培训，该环境将植物生物学，微生物学，生物物理学和蛋白质NMR光谱学的不同领域联系起来。 最近在PI实验室的代表性不足的少数民族领导联盟学生的参与将有助于在这个目标人群中的未来招聘。 PI也是助理教授芭芭拉里昂在INBRE计划在新墨西哥州州立大学（NMSU），少数民族服务机构的导师。 通过领导联盟和INBRE计划，该项目将为科学领域代表性不足的少数民族学生提供研究机会和指导。