Intercellular Signaling in Myxococcus xanthus

描述(由申请人提供)：细胞间信号对复杂的微生物事件，如发育、发病机制和生物膜的形成是必不可少的。黄色粘球菌具有复杂的生活史和协调的社会行为，是研究细胞间信号转导的良好模式菌。本研究的重点是黄花的社会滑动运动和趋化作用，这是一种参与营养体群和子实体形成的多细胞功能。以往的研究表明，黄曲霉的社会滑动运动/趋化作用涉及三个主要细胞成分的复杂相互作用：IV型菌毛(TFP)、胞外多糖(EPS)和类趋化FRZ感觉系统(FRZ)。本研究旨在了解黄花社会滑动运动/趋化的遗传和生化基础。在这项申请中提出了三个具体目标。目的1分析PilA的遗传和生化特性，以进一步了解TFP在S运动中的作用。目的2研究胞外多糖产生和分布的时空调控的分子机制，以进一步了解胞外多糖在S运动中的作用。目的3探讨TFP和EPS与其相关生物学事件之间的相互作用。这些研究的成功实施将提供对TFP-EPS-FRZ相关的社会滑动运动和趋化作用的分子理解。这些发现将揭示关于黄色微囊藻复杂发育过程中细胞间信号事件的深刻生物学知识。此外，这些研究还可以发现基于鞭毛的游泳运动和依赖于TFP的滑行运动之间可能的进化联系。由于TFP、EPS和化学感觉蛋白也是多种病原菌在生物被膜形成和组织黏附和入侵过程中的关键毒力因子，因此本研究获得的知识也可能为对抗微生物发病机制提供新的途径。

DESCRIPTION (provided by applicant): Intercellular signaling is essential for complex microbial events such as development, pathogenesis and biofilm formation. Myxococcus xanthus is an excellent model bacterium for studying intercellular signaling because of its complex life cycle and coordinated social behaviors. This study focuses on M. xanthus social gliding motility and chemotaxis, a multi-cellular function involved in vegetative swarming and fruiting body formation. Previous studies show that social gliding motility/chemotaxis of M. xanthus involves the complex interactions of three major cellular components: type IV pili (TFP), exopolysacchrides (EPS), and a chemotaxis-like Frz sensory system (Frz). This study aims to understand the genetic and biochemical basis of M. xanthus social gliding motility/chemotaxis. Three specific aims are proposed in this application. Aim 1 is to analyze the genetic and biochemical properties of PilA to further understand the role of TFP in S-motility. Aim 2 is to study the molecular mechanisms associated with temporal and spatial control of EPS production and distribution to further understand the role of EPS in S-motility. Aim 3 is to explore the interaction between TFP & EPS and its associated biological events. The successful execution of these proposed studies will provide a molecular understanding of the TFP-EPS-Frz-associated social gliding motility and chemotaxis. The findings will reveal insightful biological knowledge about intercellular signaling events during the complex development of M. xanthus. Furthermore, these studies could discover the possible evolutionary connections between flagella based swimming motility and TFP dependent gliding motility. Since TFP, EPS and chemosensory proteins are also the key virulent factors for a variety of pathogenic bacteria during biofilm formation and tissue adherence and invasion, the knowledge gained from this study could also lead to new ways to combat microbial pathogenesis.