Flavobacterium Gliding Motility:From protein secretion to cell surface movements

滑动运动是一种运动形式，通过这种运动，通常在身体内部和表面上发现的某些细菌能够在固体表面上移动。滑行运动依赖于由独特的蛋白质组成的装置，该项目将探索两个基本的细胞过程（蛋白质分泌和细胞运动）以及它们之间的相互作用，这是滑行运动的基础。研究生和本科生以及博士后研究员将积极参与该项目，并将获得涉及遗传学，分子生物学，微观和数学建模的跨学科研究经验。他们还将接受科学写作和演示方面的培训。该项目的成果将由学生在国家会议上报告，并在科学文献中发表，所开发的遗传工具将提供给科学界。这项研究的结果将被纳入本科实验室练习和公开讲座将提出传达科学发现的兴奋。该研究将解决与负责递送表面粘附素SprB的IX型分泌系统（T9 SS）的功能相关的3个具体目标，该表面粘附素SprB负责滑行运动装置。目标是：（1）使用生物化学和遗传学方法表征分泌蛋白靶向T9 SS的机制;（2）通过将荧光蛋白融合到运动装置的组分来确定运动装置的运动组分，以鉴定那些长距离快速运动的组分（对这些运动的数学分析将用于构建模型来解释滑翔）;和（3）区分T9 SS和滑行运动器，以确定哪些蛋白质主要在分泌、运动或两个过程中起作用。这将有助于确定T9 SS和滑行运动装置是两个独立的机器还是单个机器的不同方面。将检查具有T9 SS基因突变的细胞，以确定它们是否保留滑行运动功能。将分离和分析导致运动或分泌缺陷但不是两者的突变，以确定哪些蛋白质主要在分泌中起作用，哪些蛋白质在运动中起作用。对F. johnsoniae和CellulophagaalgicolaT 9 SS及其各自的滑动机器将鉴定保守特征并突出单个蛋白质在分泌或运动中的作用。所研究的细菌属于研究不足的拟杆菌门。拟杆菌门是最大的细菌门之一，其中组成T9 SS和滑动运动装置的蛋白质是常见的。然而，这些蛋白质在其他细菌中没有发现。对T9 SS和滑行机制的更全面理解将扩大我们对细菌蛋白分泌机制、细胞内动态蛋白运动和细胞表面运动的理解。

Gliding motility is a form of movement by which certain bacteria commonly found both inside and on the surface of the body are able to move themselves over solid surfaces. Gliding motility relies on an apparatus composed of unique proteins and this project will explore two fundamental cellular processes (protein secretion and cell movement) and the interactions between them that underlie gliding motility. Graduate and undergraduate students as well as postdoctoral fellows will be actively engaged in the project, and will gain experience in interdisciplinary research involving genetics, molecular biology, and microscopic and mathematical modeling. They will also receive training in scientific writing and presentation. Results of the project will be reported by students at national meetings and published in the scientific literature, and genetic tools that are developed will be made available to the scientific community. Results of this research will be incorporated into undergraduate laboratory exercises and public lectures will be presented to convey the excitement of scientific discovery. The research will address 3 specific aims related to the functioning of the type IX secretion system (T9SS) responsible for delivering surface adhesin SprB which is responsible for the gliding motility apparatus. The goals are: (1) to characterize using biochemical and genetic approaches the mechanism by which secreted proteins are targeted to the T9SS; (2) to define the moving components of the motility machinery by fusing fluorescent proteins to components of the motility apparatus to identify those that move rapidly over long distances (mathematical analyses of these movements will be used to construct models to explain gliding); and (3) to distinguish between the T9SS and the gliding motility apparatus to determine which proteins function primarily in secretion, in motility, or in both processes. This will help determine if the T9SS and the gliding motility apparatus are two independent machines or different aspects of a single machine. Cells with mutations in T9SS genes will be examined to determine if they retain gliding motor function. Mutations that result in defects in either motility or secretion, but not both, will be isolated and analyzed to determine which proteins function primarily in secretion and which function in motility. Comparative analysis of the F. johnsoniae and Cellulophaga algicola T9SSs and their respective gliding machines will identify conserved features and highlight the roles of individual proteins in secretion or motility. The bacteria studied belong to the understudied phylum, Bacteroidetes. Bacteriodetes is one of the largest bacterial phyla where the proteins that make up the T9SS and the gliding motility apparatus are common. However, these proteins are not found in other groups of bacteria. A more complete understanding of the T9SS and the gliding machinery will expand our understanding of mechanisms of bacterial protein secretion, dynamic protein movements within cells, and cell movements over surfaces.