Global regulation by horizontally transferred regulators establishes the pathogenicity of Escherichia coli
Global regulation by horizontally transferred regulators establishes the pathogenicity of Escherichia coli
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DOI：
10.1093/dnares/dsm033
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发表时间：
2008-02-01
期刊：
影响因子：
4.1
通讯作者：
Tobe, Toru
中科院分区：
文献类型：
--
作者：
Abe, Hiroyuki;Miyahara, Akira;Tobe, Toru
肠出血性大肠杆菌是一种引起腹泻和溶血性尿毒症综合征的新兴病原体。许多影响毒力的基因组信息是通过水平转移获得的。附着和消退病变所需的基因位于肠细胞消退（LEE）致病性岛位点。LEE基因的转录受到同样由LEE编码的Ler和在其他位点编码的Pch调控因子的正调控。在这里，我们通过比较改变ler和pch转录水平的影响，确定了转录谱与LEE基因相似的基因。我们根据转录谱将这些基因分为两类。通过确定Ler和Pch的结合谱，我们发现两者都参与调控一类基因，但只有Pch参与调控另一类基因。在调控基因的编码区和启动子区发现了结合位点，其中包括K12菌株共有的基因和o157特异性基因，这表明两者都是一个全局调节因子。这些结果表明，Ler和Pch协调了毒力基因的转录，这些基因通过水平转移被捕获并分散在整个染色体上。
Enterohemorrhagic Escherichia coli is an emerging pathogen that causes diarrhea and hemolytic uremic syndrome. Much of the genomic information that affects virulence is acquired by horizontal transfer. Genes necessary for attaching and effacing lesions are located in the locus for enterocyte effacement (LEE) pathogenicity island. LEE gene transcription is positively regulated by Ler, which is also encoded by the LEE, and by Pch regulators, which are encoded at other loci. Here we identified genes whose transcription profiles were similar to those of the LEE genes, by comparing the effects of altering ler and pch transcript levels. We assigned these genes into two classes, according to their transcription profiles. By determining the binding profiles for Ler and Pch, we showed that both were involved in regulating one class of genes, but only Pch was involved in regulating the other class. Binding sites were found in the coding region as well as the promoter region of regulated genes, which include genes common to K12 strains as well as O157-specific genes, suggesting that both act as a global regulator. These results indicate that Ler and Pch orchestrate the transcription of virulence genes, which are captured by horizontal transfer and scattered throughout the chromosome.