Quorum-sensing Escherichia coli regulator A:: A regulator of the LysR family involved in the regulation of the locus of enterocyte effacement pathogenicity island in enterohemorrhagic E-coli
Quorum-sensing Escherichia coli regulator A:: A regulator of the LysR family involved in the regulation of the locus of enterocyte effacement pathogenicity island in enterohemorrhagic E-coli
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DOI：
10.1128/iai.70.6.3085-3093.2002
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发表时间：
2002-06-01
影响因子：
3.1
通讯作者：
Kaper, JB
中科院分区：
文献类型：
--
作者：
Sperandio, V;Li, CYC;Kaper, JB
肠上皮细胞消失基因座（LEE）是一个染色体致病岛，编码与肠出血性大肠杆菌（EHEC）和肠致病性大肠杆菌（EHEC）的附着和消失病变形成有关的蛋白质。coli（EPEC）。LEE包含41个开放阅读框，以5个主要操纵子LEE 1、LEE 2、LEE 3、tir（LEE 5）和LEE 4组织，其编码III型分泌系统、内膜粘附素、移位的内膜受体（Tir）和其它效应蛋白。LEE 1的第一个基因编码Ler调节子，其激活LEE内的所有其他基因。我们先前报道了LEE基因被通过Ler的群体感应激活（V. Sperandio，J.L. Mellies，W.阮氏Shin和J. B. Kaper，Proc. Natl. Acad. Sci. USA 96：15196-15201，1999）。在这项研究中，我们报告了一个假定的调节E。大肠杆菌基因组本身是由群体感应激活的。该调节因子由开放阅读框b3243编码;属于LysR调节因子家族;存在于EHEC、EPEC和E. coliK-12;并分别与霍乱弧菌和铜绿假单胞菌的AphB和PtxR调节子具有同源性。我们通过使用转录融合证实了b3243通过群体感应激活，并将该调节因子重新命名为群体感应E。coli regulator A（QseA）。我们观察到，QseA激活ler的转录，因此其他LEE基因。肠出血性大肠杆菌qseA突变体有一个显着减少III型分泌活性，这是补充时，qseA提供反式。类似的结果也观察到与EPEC的qseA突变体。QseA调节子是通过群体感应调节EHEC和EPEC毒力基因的调节级联的一部分。
The locus of enterocyte effacement (LEE) is a chromosomal pathogenicity island that encodes the proteins involved in the formation of the attaching and effacing lesions by enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC). The LEE comprises 41 open reading frames organized in five major operons, LEE1, LEE2, LEE3, tir (LEE5), and LEE4, which encode a type III secretion system, the intimin adhesin, the translocated intimin receptor (Tir), and other effector proteins. The first gene of LEE1 encodes the Ler regulator, which activates all the other genes within the LEE. We previously reported that the LEE genes were activated by quorum sensing through Ler (V. Sperandio, J. L. Mellies, W. Nguyen, S. Shin, and J. B. Kaper, Proc. Natl. Acad. Sci. USA 96:15196-15201, 1999). In this study we report that a putative regulator in the E. coli genome is itself activated by quorum sensing. This regulator is encoded by open reading frame b3243; belongs to the LysR family of regulators; is present in EHEC, EPEC, and E. coli K-12; and shares homology with the AphB and PtxR regulators of Vibrio cholerae and Pseudomonas aeruginosa, respectively. We confirmed the activation of b3243 by quorum sensing by using transcriptional fusions and renamed this regulator quorum-sensing E. coli regulator A (QseA). We observed that QseA activated transcription of ler and therefore of the other LEE genes. An EHEC qseA mutant had a striking reduction of type III secretion activity, which was complemented when qseA was provided in trans. Similar results were also observed with a qseA mutant of EPEC. The QseA regulator is part of the regulatory cascade that regulates EHEC and EPEC virulence genes by quorum sensing.