Feedback control of the pleiotropic regulators and H-NS antagonists LeuO and RcsB-BglJ in Escherichia coli

大肠杆菌中多效调节剂和 H-NS 拮抗剂 LeuO 和 RcsB-BglJ 的反馈控制

• 批准号: 86649608
• 负责人: Professorin Dr. Karin Schnetz
• 金额: --
• 依托单位: Arbeitsgruppe Bacterial Genetics
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/86649608?language=en
• 关键词: Feedback; control; pleiotropic; regulators; NS

H-NS has a major role in repression of horizontally acquired AT-rich DNA and of genes for responses to various stress conditions and changes in the environment associated with the host habitat. Silencing by H-NS is based on the formation of nucleoprotein complexes on AT-rich DNA, and is modulated and relieved locus specifically. In this project we wish to analyze a regulatory cascade that involves the LysR-type transcription factor LeuO and the LuxR-type transcription factors YjjQ and BglJ. LeuO and YjjQ are transcription factors important for virulence of Salmonella enterica and avian pathogenic Escherichia coli, respectively. LeuO, whose expression is H-NS-repressed and positively auto-regulated, counteracts the H-NS mediated repression of the yjjQ-bglJ operon. YjjQ and BglJ both interact with the response regulator RcsB of the Rcs membrane and peptidoglycan stress signaling system. The so far only known target gene of these proteins is the H-NS repressed bgl operon whose repression is relieved by the BglJ/RcsB heterodimer. The aims of the project are to characterize (i) the molecular mechanism underlying de-repression of the yjjQ-bglJ operon by LeuO and (ii) the role of BglJ and YjjQ in control of H-NS repressed and other loci and in their relation to the Rcs signal transduction system in commensal and pathogenic E.coli.

H-NS在抑制水平获得的富含AT的DNA和对各种应激条件和与宿主栖息地相关的环境变化的反应的基因中具有重要作用。H-NS的沉默作用是通过在富含AT的DNA上形成核蛋白复合物来实现的，并且是位点特异性的调节和解除。在这个项目中，我们希望分析一个涉及LysR型转录因子LeuO和LuxR型转录因子YjjQ和BglJ的调控级联。LeuO和YjjQ分别是肠道沙门氏菌和禽致病性大肠杆菌毒力的重要转录因子。LeuO，其表达是H-NS抑制的和正性自调节的，抵消了H-NS介导的yjjQ-bglJ操纵子的抑制。YjjQ和BglJ都与Rcs膜和肽聚糖应激信号系统的反应调节剂RcsB相互作用。迄今为止，这些蛋白质的唯一已知靶基因是H-NS抑制的bgl操纵子，其抑制被BglJ/RcsB异源二聚体解除。该项目的目的是表征（i）LeuO对yjjQ-bglJ操纵子去阻遏的分子机制和（ii）BglJ和YjjQ在控制H-NS阻遏和其他位点中的作用以及它们与大肠杆菌和致病性大肠杆菌中Rcs信号转导系统的关系。

项目成果

YjjQ Represses Transcription of flhDC and Additional Loci in Escherichia coli

• DOI: 10.1128/jb.00263-15
• 发表时间: 2015-06
• 期刊: Journal of Bacteriology
• 影响因子: 3.2
• 作者: Helene Wiebe;D. Gürlebeck;Jana Groß;Katrin Dreck;Derk Pannen;C. Ewers;L. Wieler;K. Schnetz