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。它遵循 致病性革兰氏阴性菌中存在许多进化上不同的蛋白质易位途径， 细菌（I-VI型）。VI型分泌（T6 S）是这些途径中最新描述的，是一种重要的 是许多致病菌毒力的贡献者。本提案的PI，约瑟夫·穆戈斯博士，首先 在铜绿假单胞菌中表征了该分泌系统。这项工作产生了根本性的 对分泌系统的生化和结构的见解;此外，它提供了T6 S 铜绿假单胞菌的T6 SS系统对于这种生物体在体内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Mougous博士的主要研究重点， 实验室，是为了了解调节途径，密切调节铜绿假单胞菌的活动， T6SS这一途径，这是真核生物的信号，是由二聚化的一个 跨膜丝氨酸-苏氨酸激酶。这引发了一系列“触发”分泌系统的事件， 导致底物移位。尽管Mougous博士先前的工作揭示了一些 关于这一途径的细节，许多关键问题仍然没有答案。拟议的实验试图回答 这些机械问题，并利用这种新的监管模式，以确定 分泌系统的底物-场的电流障碍。许多重要的病原体 人类健康和生物防御需要T6 S用于毒力并使用该途径来调节其活性;因此， 拟议的研究所产生的结果将产生广泛的影响，并可能导致发展 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.