Post-translational regulation of type VI secretion in Pseudomonas aeruginosa

项目摘要 细菌的毒力与其释放分泌因子的能力密切相关。由此可以得出结论 在致病性革兰氏阴性菌中存在许多进化上不同的蛋白质转位途径 细菌(I-VI型)。VI型分泌物(T6S)是这些途径中最新描述的，是一种重要的 许多致病细菌毒力的贡献者。这项提案的主办人约瑟夫·莫格斯博士首先 在铜绿假单胞菌中表征了这种分泌系统。这项工作产生了根本的影响 对分泌系统的生化和结构洞察；此外，它还提供了T6S 铜绿假单胞菌的系统(T6SS)对该菌引起的破坏性慢性感染很重要 囊性纤维化患者。这一建议的重点，以及穆古斯博士的主要研究重点 实验室的目的是了解紧密调节铜绿假单胞菌活性的调控途径。 T6SS。这条让人联想到真核信号传递的途径，是由一种二聚体 跨膜型丝氨酸-苏氨酸激酶。这会引发一系列事件，“触发”分泌系统， 导致底物移位。尽管Mougous博士之前的工作揭示了一些机制 关于这一途径的细节，许多关键问题仍未得到解答。拟议中的实验试图回答 这些机械性的问题，并利用这一新的监管模式来确定 分泌系统的底物--场的电流障碍。许多具有重要意义的病原体 人类的健康和生物防御需要T6S的毒力，并使用这一途径来调节其活性；因此， 拟议研究产生的结果将具有广泛的影响，并可能导致 新的治疗策略。

Project Abstract The virulence of a bacterium is closely linked to its ability to release secreted factors. It follows that many evolutionarily distinct pathways exist for the translocation of proteins in pathogenic Gram-negative bacteria (types I-VI). Type VI secretion (T6S), the most recently described of these pathways, is an important contributor to the virulence of many pathogenic bacteria. The PI of this proposal, Dr. Joseph Mougous, first characterized this secretion system in Pseudomonas aeruginosa. This work produced fundamental biochemical and structural insights into the secretion system; furthermore, it provided evidence that the T6S system (T6SS) of P. aeruginosa is important for the devastating chronic infections this organism causes in cystic fibrosis patients. The focus of this proposal, and the major research emphasis of Dr. Mougous' laboratory, is to understand the regulatory pathway that tightly modulates the activity of the P. aeruginosa T6SS. This pathway, which is reminiscent of eukaryotic signaling, is initiated by dimerization of a transmembrane serine-threonine kinase. This provokes a series of events that "triggers" the secretion system, leading to substrate translocation. Although prior work by Dr. Mougous has revealed some of the mechanistic details of this pathway, many key questions remain unanswered. The proposed experiments seek to answer these mechanistic questions, and also to utilize this novel mode of regulation for the purpose of identifying substrates of the secretion system - a current impediment to the field. Many pathogens of significance to human health and biodefense require T6S for virulence and use this pathway to regulate its activity; therefore, findings generated by the proposed research will have broad implications and could lead to the development of new therapeutic strategies.