Genome-wide Profiling of Promoter Recognition by the Two-component Response Regulator CpxR-P in Escherichia coli

Wulf, Peter De; McGuire, Abigail M.; Liu, Xueqiao; Lin, E. C. C.

doi:10.1074/jbc.m203487200

Cited by 201 publications

(260 citation statements)

References 39 publications

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“…9). A situation similar to the situation described here has been observed for the CpxR regulators in other bacteria (14). Besides the differences in the locations of the two regulators and in the orientations of their regulatory elements, the PmrA regulator was found to function as an activator of its target genes in all the genes examined thus far, whereas the CpxR regulator was found to function as a repressor or as an activator of its target genes (Fig.…”

Section: Discussionsupporting

confidence: 52%

The Response Regulator CpxR Directly Regulates Expression of SeveralLegionella pneumophila icm/dotComponents as Well as New Translocated Substrates

2008

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Legionella pneumophila has been shown to utilize the icm/dot type IV secretion system for pathogenesis. This system was shown to be composed of icm/dot complex components and accessory proteins, as well as a large number of translocated substrates. Bioinformatic analysis of the regulatory regions of all the genes revealed that several icm/dot genes, as well as two genes encoding icm/dot translocated substrates, contain the conserved CpxR regulatory element, a regulator that has been shown previously to control the expression of the icmR gene. An experimental analysis, which included a comparison of gene expression in a L. pneumophila wild-type strain and gene expression in a cpxR deletion mutant, construction of mutants with mutations in the CpxR conserved regulatory elements, controlled expression studies, and mobility shift assays, demonstrated the direct relationship between the CpxR regulator and the expression of the genes. Furthermore, genomic analysis identified nine additional genes that contain a putative CpxR regulatory element; five of these genes (two legA genes and three ceg genes) were suggested previously to be putative icm/dot translocated substrates. The three ceg genes identified, which were shown previously to contain a putative PmrA regulatory element, were found here to be regulated by both CpxR and PmrA. The other six genes (two legA genes and four new genes products were found to be regulated by CpxR. Moreover, using the CyaA translocation assay, these nine gene products were found to be translocated into host cells in an Icm/Dot-dependent manner. Our results establish that the CpxR regulator is a fundamental regulator of the icm/dot type IV secretion system in L. pneumophila.

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Section: Discussionsupporting

confidence: 52%

The Response Regulator CpxR Directly Regulates Expression of SeveralLegionella pneumophila icm/dotComponents as Well as New Translocated Substrates

2008

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“…Moreover, we identified another possible CpxR-binding box that was specific for S. Typhimurium (Fig. 3) which had high similarity to the CpxR consensus sequence (De Wulf et al, 2002). The differences in the 210 regions of the htrAp1 and htrAp2 promoters between S. Typhimurium and E. coli are conserved in uropathogenic and enterohaemorrhagic strains of E. coli (serotypes O73 and O157) (data not shown).…”

Section: Discussionmentioning

confidence: 92%

Salmonella enterica Serovar Typhimurium HtrA: regulation of expression and role of the chaperone and protease activities during infection

Lewis

Škovierová²,

Rowley

et al. 2009

Microbiology

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HtrA is a bifunctional stress protein required by many bacterial pathogens to successfully cause infection. Salmonella enterica serovar Typhimurium (S. Typhimurium) htrA mutants are defective in intramacrophage survival and are highly attenuated in mice. Transcription of htrA in Escherichia coli is governed by a single promoter that is dependent on s E (RpoE). S. Typhimurium htrA also possesses a s E -dependent promoter; however, we found that the absence of s E had little effect on production of HtrA by S. Typhimurium. This suggests that additional promoters control expression of htrA in S. Typhimurium. We identified three S. Typhimurium htrA promoters. Only the most proximal promoter, htrAp3, was s E dependent. The other promoters, htrAp1 and htrAp2, are probably recognized by the principal sigma factor s 70 . These two promoters were constitutively expressed but were also slightly induced by heat shock. Thus expression of htrA is different in S. Typhimurium and E. coli. The role of HtrA is to deal with misfolded/damaged proteins in the periplasm. It can do this either by degrading (protease activity) or folding/capturing (chaperone/sequestering, C/S, activity) the aberrant protein. We investigated which of these functions are important to S. Typhimurium in vitro and in vivo. Point or deletion mutants of htrA that encode variant HtrA molecules have been used in previous studies to investigate the role of different regions of HtrA in C/S and protease activity. These htrA variants were placed under the control of the S. Typhimurium htrAP123 promoters and expressed in a S. Typhimurium htrA mutant, GVB1343. Both wild-type HtrA and HtrA (HtrA S210A) lacking protease activity enabled GVB1343 to grow at high temperature (46 6C). Both molecules also significantly enhanced the growth/survival of GVB1343 in the liver and spleen of mice during infection. However, expression of wild-type HtrA enabled GVB1343 to grow to much higher levels than expression of HtrA S210A. Thus both the protease and C/S functions of HtrA operate in vivo during infection but the protease function is probably more important. Absence of either PDZ domain completely abolished the ability of HtrA to complement the growth defects of GVB1343 in vitro or in vivo.

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“…Importantly, key genes whose functions affect this mode of DNA-based oxidative cell death are not regulated by H 2 O 2 -inducible OxyR or by SoxRS but rather by other stress regulators: e.g., mutM (RpoH) (51), mutY (Fur/ArcA/Fnr, normally down-regulated upon oxidative stress but up-regulated upon MalE-LacZ induction) (52), and mutT (CpxA/CpxR in an operon with secM and secA) (53), and dinB/recA (SOS) (54). Thus, the intracellular environment of cells generating endogenous H 2 O 2 as a consequence of a stress can be very different from the intracellular environment of cells treated with exogenous H 2 O 2 .…”

Section: Discussionmentioning

confidence: 99%

Lethality of MalE-LacZ hybrid protein shares mechanistic attributes with oxidative component of antibiotic lethality

Takahashi

Gruber

Yang

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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Downstream metabolic events can contribute to the lethality of drugs or agents that interact with a primary cellular target. In bacteria, the production of reactive oxygen species (ROS) has been associated with the lethal effects of a variety of stresses including bactericidal antibiotics, but the relative contribution of this oxidative component to cell death depends on a variety of factors. Experimental evidence has suggested that unresolvable DNA problems caused by incorporation of oxidized nucleotides into nascent DNA followed by incomplete base excision repair contribute to the ROSdependent component of antibiotic lethality. Expression of the chimeric periplasmic-cytoplasmic MalE-LacZ 72-47 protein is an historically important lethal stress originally identified during seminal genetic experiments that defined the SecY-dependent protein translocation system. Multiple, independent lines of evidence presented here indicate that the predominant mechanism for MalE-LacZ lethality shares attributes with the ROS-dependent component of antibiotic lethality. MalE-LacZ lethality requires molecular oxygen, and its expression induces ROS production. The increased susceptibility of mutants sensitive to oxidative stress to MalE-LacZ lethality indicates that ROS contribute causally to cell death rather than simply being produced by dying cells. Observations that support the proposed mechanism of cell death include MalE-LacZ expression being bacteriostatic rather than bactericidal in cells that overexpress MutT, a nucleotide sanitizer that hydrolyzes 8-oxo-dGTP to the monophosphate, or that lack MutM and MutY, DNA glycosylases that process base pairs involving 8-oxo-dGTP. Our studies suggest stress-induced physiological changes that favor this mode of ROS-dependent death.A gents or conditions that inhibit important biological processes can kill cells. However, physiological processes metabolically downstream of the initial inhibition can also contribute to cell death (1). For example, β-lactam antibiotics not only inhibit penicillin-binding proteins leading to lysis; they also induce a futile cycle of cell wall synthesis and degradation that contributes to their killing (2). In another example, lethal attacks on Escherichia coli mediated by the type VI secretion system P1vir phage and the antimicrobial peptide polymyxin B elicit the production of reactive oxygen species (ROS) that contribute to cell death (3). In bacteria, ROS production has been associated with the lethal effects of diverse stresses (4). In most cases, the detailed mechanisms responsible for ROS production are poorly understood; however, a variety of futile metabolic cycles can elicit H 2 O 2 production, illustrating the breadth of possible metabolic perturbations that could potentially induce oxidative stress (5).Despite widespread evidence that endogenous ROS produced as a consequence of metabolic stress can be lethal to bacteria and eukaryotes, the application of this concept to antibiotic lethality has been complicated. Evidence from multiple investiga...

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Genome-wide Profiling of Promoter Recognition by the Two-component Response Regulator CpxR-P in Escherichia coli

Cited by 201 publications

References 39 publications

The Response Regulator CpxR Directly Regulates Expression of SeveralLegionella pneumophila icm/dotComponents as Well as New Translocated Substrates

The Response Regulator CpxR Directly Regulates Expression of SeveralLegionella pneumophila icm/dotComponents as Well as New Translocated Substrates

Salmonella enterica Serovar Typhimurium HtrA: regulation of expression and role of the chaperone and protease activities during infection

Lethality of MalE-LacZ hybrid protein shares mechanistic attributes with oxidative component of antibiotic lethality

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