The Psp response of Yersinia enterocolitica

描述（由申请人提供）：耶尔森氏菌属细菌是多种人类疾病的致病菌。Y.鼠疫杆菌引起腺鼠疫，由于其作为生物恐怖主义的潜在用途，最近在公众意识中重新获得突出地位。相比之下，Y. pseudotuberculosis和Y.小肠结肠炎主要引起胃肠道疾病。然而，尽管疾病症状存在差异，但这三种致病性耶尔森氏菌属物种密切相关，并共享几个共同的毒力决定因素。耶尔森氏菌的研究为细菌的发病机制提供了基本的见解，包括广泛分布的III型分泌系统（TTSS）的第一个例子。在耶尔森氏菌中，与所有细菌病原体一样，许多在毒力中起重要作用的蛋白质，包括TTSS的组分，位于细胞包膜中。在某些条件下，一些包膜蛋白会错误折叠/错误定位。特定的应激反应机制处理这个问题，例如大肠杆菌和相关生物的RpoE和Cpx系统。这些细胞质外应激反应在宿主感染过程中起着重要作用。这个建议的中心假设是，一个不同的胞质外应激反应系统是由噬菌体休克蛋白基因座（psp）编码的。小肠结肠炎 解脂耶小肠结肠炎psp突变体是无毒的，并且在其他细菌病原体（包括Y.鼠疫和霍乱弧菌。我们的初步数据表明，Psp系统响应于参与毒力的几个包膜蛋白的错误定位，包括至少一个组件的TTSS。通过研究Psp系统，我们将进一步了解细菌对宿主感染期间发生的应激条件做出反应的基本能力。具体而言，我们建议：（1）分析诱导Psp系统的蛋白质并表征Psp诱导剂和RpoE/Cpx诱导剂之间的任何重叠;（2）确定Psp系统的拓扑结构，并研究Psp如何允许跨细胞质膜感测和发信号通知细胞质外应激;（3）表征由Psp系统直接控制的基因，以鉴定进一步的应激反应组分。

DESCRIPTION (provided by applicant): Bacteria of the genus Yersinia are responsible for a variety of human diseases. Y. pestis causes Bubonic Plague, and has recently regained prominence in public awareness due to its potential use as an agent of bioterrorism. In contrast, Y. pseudotuberculosis and Y. enterocolitica cause primarily gastrointestinal disease. However, despite the differences in disease symptoms, the three pathogenic Yersinia species are closely related, and share several common virulence determinants. Yersinia studies have provided fundamental insights into bacterial pathogenesis, including the first example of the widespread type III secretion system (TTSS). In Yersinia, as in all bacterial pathogens, many of the proteins that play important roles in virulence, including components of the TTSS, are located in the cell envelope. Under certain conditions, some envelope proteins become misfolded/mislocalized. Specific stress-response mechanisms deal with this problem, examples of which are the RpoE and Cpx systems of Escherichia coli and related organisms. These extracytoplasmic stress responses play important roles during host infection. The central hypothesis of this proposal is that a different extracytoplasmic stress response system is encoded by the phage-shock-protein locus (psp) of Y. enterocolitica. A Y. enterocolitica psp mutant is avirulent, and homologus psp loci are found in other bacterial pathogens, including Y. pestis and Vibrio cholerae. Our preliminary data indicate that the Psp system responds to mislocalization of several envelope proteins involved in virulence, including at least one component of a TTSS. By studying the Psp system we will gain further insight into the essential ability of bacteria to respond to stressful conditions that occur during host infection. Specifically, we propose to: (1) Analyze the proteins that induce the Psp system and characterize any overlap between Psp inducers and RpoE/Cpx inducers; (2) Determine the topology of the Psp system, and investigate how Psp allows extracytoplasmic stress to be sensed and signaled across the cytoplasmic membrane; (3) Characterize genes directly controlled by the Psp system, in order to identify further stress response components.