Dipartimento di Biologia Strutturale e Funzionale, Università Federico II, Napoli, Italy.
FEMS Microbiol Lett. 2011 Dec;325(1):64-70. doi: 10.1111/j.1574-6968.2011.02411.x. Epub 2011 Oct 3.
Citrobacter rodentium is a mouse pathogen that, because of its similarities with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) strains of Escherichia coli is widely used as a model system for in vivo and in vitro studies. Similarly to EPEC and EHEC, C. rodentium carries the LEE (locus of enterocyte effacement) pathogenicity island, encoding virulence factors essential for causing transmissible colonic hyperplasia in mice by attaching and effacing (A/E) lesions. Expression of the genes carried by the LEE pathogenicity island is controlled by complex networks of transcriptional factors, including the global regulators H-NS, IHF, and Fis. In this study, we analyzed the role of Lrp, another global regulator of gene expression in enteric bacteria, on the expression of LEE genes of C. rodentium. To this aim, a real-time PCR approach was used and revealed a negative role of Lrp on the expression of all analyzed LEE genes. Mobility-shift experiments indicated that Lrp action is direct on LEE1 and indirect on all other analyzed LEE genes.
柠檬酸杆菌是一种鼠病原体，由于其与人类肠致病性（EPEC）和肠出血性（EHEC）大肠杆菌菌株的相似性，被广泛用作体内和体外研究的模型系统。与 EPEC 和 EHEC 类似，柠檬酸杆菌携带 LEE（肠上皮细胞消失的基因座）致病性岛，编码通过附着和消失（A/E）病变引起小鼠传染性结肠增生所必需的毒力因子。LEE 致病性岛携带的基因的表达受转录因子的复杂网络控制，包括全局调节剂 H-NS、IHF 和 Fis。在这项研究中，我们分析了另一种肠道细菌基因表达的全局调节剂 Lrp 对柠檬酸杆菌 LEE 基因表达的作用。为此，使用实时 PCR 方法表明 Lrp 对所有分析的 LEE 基因的表达具有负调控作用。迁移率变动实验表明 Lrp 对 LEE1 的作用是直接的，对所有其他分析的 LEE 基因的作用是间接的。
