QUORUM SENSING IN BACTERIAL TWITCHING MOTILITY

铜绿假单胞菌是一种普遍存在的重要机会致病菌， 病原体拥有令人印象深刻的毒力因子库。两 群体感应系统，LAS和RHL，已被确定为控制 这些毒力因子中的几种的生产，并已成为一个模型， 研究毒力基因的细胞密度控制。证据表明 铜绿假单胞菌的群体感应系统在抽搐中起主要作用 动力学是第一次在这里提出。最近，铜绿假单胞菌 也成为研究4型皮利和抽搐的首选模型系统 能动性铜绿假单胞菌的极性4型皮利是多功能的 这些结构在这种生物的毒力中起着至关重要的作用， 促进对多种组织的粘附和定殖，以及 作为负责抽搐运动的细胞器。的总目标 这项研究的目的是找出细胞和分子基础的作用， 在鞭毛独立，菌毛相关模式的细菌群体感应 表面易位称为'抽搐运动'在铜绿假单胞菌。主 该项目的目标是确定抽搐运动基因， 由铜绿假单胞菌的群体感应系统控制。 抽搐运动的细胞和分子机制尚不清楚 理解，也不清楚群体感应系统如何影响这些 机制等抽搐运动的机制及其与 群体感应将在遗传，生物化学和细胞-细胞 互动水平。最后，贡献群体感应和抽搐 运动性使铜绿假单胞菌的配偶交配频率 将首次检查半固体表面。标准板匹配 野生型细胞和各种抽搐运动和群体感应之间的关系 变种人将进行。此外，基因的时空特性 半固体表面上种群成员之间的转移将是 在单细胞水平上使用GFP的合成来跟踪接合 转移

Pseudomonas aeruginosa is a ubiquitous and important opportunistic pathogen that possesses an impressive arsenal of virulence factors. Two quorum-sensing systems, las and rhl, have been identified as controlling production of several of these virulence factors and has become a model for studying cell-density control of virulence genes. Evidence that the quorum-sensing systems of P. aeruginosa play a major role in twitching motilitiy is presented here for the first time. Recently, P. aeruginosa has also become the preferred model system for studies of type-4 pili and twitching motility. The polar, type-4 pili of P. aeruginosa are multifunctional structures which play a crucial role in the virulence of this organism by promoting adherence to, and colonization of, a variety of tissues as well as being the organelles responsible for twitching motility. The overall goal of this research is to work out the cellular and molecular basis for the role of quorum sensing in the flagella-independent, pili-associated mode of bacterial surface translocation known as 'twitching motility' in P. aeruginosa. A primary goal of this project is to identify the twitching motility gene(s) that are controlled by the quorum-sensing systems of P. aeruginosa. The cellular and molecular mechanisms of twitching motility are not well understood, nor is it clear how the quorum-sensing systems affect these mechanisms. The mechanisms underlying twitching motility, and its connection to quorum-sensing will be addressed at the genetic, biochemical and cell-cell interaction levels. Finally, the contributions quorum-sensing and twitching motility make to the frequency of conjugal mating in P. aeruginosa on semi-solid surfaces will be examined for the first time. Standard plate matings between wild-type cells and the various twitching motility and quorum-sensing mutants will be conducted. In addition, the temporal and spatial nature of gene transfer among members of the populations on semi-solid surfaces will be studies at the single cell level using synthesis of GFP to follow conjugal transfer.