Transcription Regulation in Pseudomonas aeruginosa

铜绿假单胞菌是一种重要的人类机会致病菌， 囊性纤维化（CF）患者发病和死亡的主要原因; CF肺的慢性定植 铜绿假单胞菌感染通常导致进行性肺损伤，并最终导致呼吸衰竭和死亡。 本工作将阐明Tex的功能和作用机制，Tex是一个公认的转录因子 来自铜绿假单胞菌，其是在慢性疾病模型中感染宿主肺所需的。 Tex在细菌中高度保守，是真核生物转录延伸因子的同源物 Spt6。这项研究的基本假设是，特克斯在铜绿假单胞菌中起着重要作用。 通过影响毒力基因的表达而致病，这些毒力基因本身对于感染是重要的， 或者在宿主体内生存为了支持这一想法，初步实验表明特克斯与 RNA聚合酶（RNAP）是基因表达的中心酶，Tex可以影响基因的表达 铜绿假单胞菌的一部分基因此外，这些实验表明，特克斯不仅与 与RNAP，但也与一个假定的多亚基复合物的成分，称为RNA降解体： 含核糖核酸酶的复合物首先在E.大肠杆菌，预计主要涉及 mRNA的降解。这些发现提出了转录机制可能是 在操作上与铜绿假单胞菌中的RNA降解机制相关。可以想象，这种联系 促进特定转录本的任何必要处理或降解，并可能代表一种新颖的 引发基因控制的机制。 这项研究将确定其表达受特克斯影响的基因，确定共同纯化的RNA， 与特克斯，并测试特定的模型如何特克斯可能影响基因表达。用高分辨率 作为指导，我们将探讨特克斯的结构特征是重要的， 功能此外，我们将进一步研究含有特克斯和凯科斯群岛的蛋白质复合物的性质， 研究Tex与RNAP和P. 铜绿。 拟议的实验不仅应该阐明特克斯在分子基础上的重要性， 发病机制，但也可能促进新的治疗剂，可用于开发 对抗CF肺中的铜绿假单胞菌感染。

Pseudomonas aeruginosa is an important opportunistic pathogen of humans that is notorious for being the principal cause of morbidity and mortality in Cystic Fibrosis (CF) patients; chronic colonization of the CF lung by P. aeruginosa typically leads to progressive lung damage, and eventually respiratory failure and death. The proposed work will elucidate the function and mechanism of action of Tex, a putative transcription factor from P. aeruginosa that is required for infection of the host lung in a chronic disease model. Tex is highly conserved amongst bacteria, and is a homolog of the eukaryotic transcription elongation factor Spt6. The underlying hypothesis for the proposed study is that Tex plays an important role in P. aeruginosa pathogenesis by influencing the expression of virulence genes that are themselves important for infection of, or survival within, the host. In support of this idea, preliminary experiments indicate that Tex associates with RNA polymerase (RNAP), the central enzyme of gene expression, and that Tex can influence the expression of a subset of genes in P. aeruginosa. Furthermore these experiments reveal that Tex associates not only with RNAP but also with components of a putative multi-subunit complex, termed the RNA degradosome: a ribonuclease-containing complex first described in E. coli that is predicted to be primarily involved in the degradation of mRNA. These findings raise the possibility that the transcription machinery may be operationally linked to the RNA degradation machinery in P. aeruginosa. Such a link could conceivably facilitate any requisite processing or degradation of a particular transcript and may represent a novel mechanism for eliciting gene control. The proposed studies will identify genes whose expression is influenced by Tex, identify RNAs that co-purify with Tex, and test specific models for how Tex might influence gene expression. With a high-resolution crystal structure of Tex as a guide, we will explore which structural features of Tex are important for its function. Moreover, we will investigate further the nature of those protein complexes that contain Tex and investigate the interactions of Tex with both RNAP and components of the putative degradosome in P. aeruginosa. The proposed experiments should not only shed light on the molecular basis for the importance of Tex in pathogenesis, but may also facilitate the development of novel therapeutic agents that can be used to combat P. aeruginosa infection in the CF lung.