scholarly journals Mutations in the Two-Component GluS-GluR Regulatory System Confer Resistance to β-Lactam Antibiotics in Burkholderia glumae

2021 ◽  
Vol 12 ◽  
Author(s):  
Joan Marunga ◽  
Eunhye Goo ◽  
Yongsung Kang ◽  
Ingyu Hwang
Keyword(s):  
Antibiotic Resistance ◽  
Response Regulator ◽  
Model Organism ◽  
Regulatory System ◽  
Resistance Mechanisms ◽  
Promoter Regions ◽  
Burkholderia Glumae ◽  
Signaling Systems ◽  
Two Component ◽  
Genes Encoding

Bacteria have specific signaling systems to overcome selective pressure, such as exposure to antibiotics. The two-component system (TCS) plays an important role in the development of antibiotic resistance. Using the rice pathogen Burkholderia glumae BGR1 as a model organism, we showed that the GluS (BGLU_1G13350) – GluR (BGLU_1G13360) TCS, consisting of a sensor kinase and response regulator, respectively, contributes to β-lactam resistance through a distinct mechanism. Inactivation of gluS or gluR conferred resistance to β-lactam antibiotics in B. glumae, whereas wild-type (WT) B. glumae was susceptible to these antibiotics. In gluS and gluR mutants, the expression of genes encoding metallo-β-lactamases (MBLs) and penicillin-binding proteins (PBPs) was significantly higher than in the WT. GluR-His bound to the putative promoter regions of annotated genes encoding MBL (BGLU_1G21360) and PBPs (BGLU_1G13280 and BGLU_1G04560), functioning as a repressor. These results demonstrate that the potential to attain β-lactam resistance may be genetically concealed in the TCS, in contrast to the widely accepted view of the role of TCS in antibiotic resistance. Our findings provide a new perspective on antibiotic resistance mechanisms, and suggest a different therapeutic approach for successful control of bacterial pathogens.

scholarly journals Characterization of the CpxRA Regulon in Haemophilus ducreyi

2010 ◽  
Vol 78 (11) ◽  
pp. 4779-4791 ◽  
Author(s):  
Maria Labandeira-Rey ◽  
Chad A. Brautigam ◽  
Eric J. Hansen
Keyword(s):  
Stress Response ◽  
Response Regulator ◽  
Cell Envelope ◽  
Bacterial Species ◽  
Regulatory System ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Envelope Stress ◽  
Two Component ◽  
Genes Encoding

ABSTRACT The H aemophilus ducreyi 35000HP genome encodes a homolog of the CpxRA two-component cell envelope stress response system originally characterized in E scherichia coli. CpxR, the cytoplasmic response regulator, was shown previously to be involved in repression of the expression of the lspB-lspA2 operon (M. Labandeira-Rey, J. R. Mock, and E. J. Hansen, Infect. Immun. 77:3402-3411, 2009). In the present study, the H. ducreyi CpxR and CpxA proteins were shown to closely resemble those of other well-studied bacterial species. A cpxA deletion mutant and a CpxR-overexpressing strain were used to explore the extent of the CpxRA regulon. DNA microarray and real-time reverse transcriptase (RT) PCR analyses indicated several potential regulatory targets for the H. ducreyi CpxRA two-component regulatory system. Electrophoretic mobility shift assays (EMSAs) were used to prove that H. ducreyi CpxR interacted with the promoter regions of genes encoding both known and putative virulence factors of H. ducreyi, including the lspB-lspA2 operon, the flp operon, and dsrA. Interestingly, the use of EMSAs also indicated that H. ducreyi CpxR did not bind to the promoter regions of several genes predicted to encode factors involved in the cell envelope stress response. Taken together, these data suggest that the CpxRA system in H. ducreyi, in contrast to that in E. coli, may be involved primarily in controlling expression of genes not involved in the cell envelope stress response.

scholarly journals Characterization of a Novel Bile-Inducible Operon Encoding a Two-Component Regulatory System in Lactobacillus acidophilus

2007 ◽  
Vol 189 (13) ◽  
pp. 4624-4634 ◽  
Author(s):  
Erika A. Pfeiler ◽  
M. Andrea Azcarate-Peril ◽  
Todd R. Klaenhammer
Keyword(s):  
Lactobacillus Acidophilus ◽  
Response Regulator ◽  
Regulatory System ◽  
Hypothetical Protein ◽  
Cellular Growth ◽  
Transcriptional Analysis ◽  
Bile Tolerance ◽  
Two Component ◽  
Genes Encoding ◽  
Global Transcriptional Profile

ABSTRACT Lactobacillus acidophilus NCFM is an industrially important strain used extensively as a probiotic culture. Tolerance of the presence of bile is an attribute important to microbial survival in the intestinal tract. A whole-genome microarray was employed to examine the effects of bile on the global transcriptional profile of this strain, with the intention of elucidating genes contributing to bile tolerance. Genes involved in carbohydrate metabolism were generally induced, while genes involved in other aspects of cellular growth were mostly repressed. A 7-kb eight-gene operon encoding a two-component regulatory system (2CRS), a transporter, an oxidoreductase, and four hypothetical proteins was significantly upregulated in the presence of bile. Deletion mutations were constructed in six genes of the operon. Transcriptional analysis of the 2CRS mutants showed that mutation of the histidine protein kinase (HPK) had no effect on the induction of the operon, whereas the mutated response regulator (RR) showed enhanced induction when the cells were exposed to bile. These results indicate that the 2CRS plays a role in bile tolerance and that the operon it resides in is negatively controlled by the RR. Mutations in the transporter, the HPK, the RR, and a hypothetical protein each resulted in loss of tolerance of bile. Mutations in genes encoding another hypothetical protein and a putative oxidoreductase resulted in significant increases in bile tolerance. This functional analysis showed that the operon encoded proteins involved in both bile tolerance and bile sensitivity.

scholarly journals Fumarate Regulation of Gene Expression in Escherichia coli by the DcuSR (dcuSR Genes) Two-Component Regulatory System

1998 ◽  
Vol 180 (20) ◽  
pp. 5421-5425 ◽  
Author(s):  
Evelyn Zientz ◽  
Johannes Bongaerts ◽  
Gottfried Unden
Keyword(s):  
Escherichia Coli ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Regulation Of Gene Expression ◽  
Regulatory System ◽  
E Coli ◽  
Expression In Escherichia Coli ◽  
Two Component ◽  
Genes Encoding ◽  
Periplasmic Domain

ABSTRACT In Escherichia coli the genes encoding the anaerobic fumarate respiratory system are transcriptionally regulated by C4-dicarboxylates. The regulation is effected by a two-component regulatory system, DcuSR, consisting of a sensory histidine kinase (DcuS) and a response regulator (DcuR). DcuS and DcuR are encoded by the dcuSR genes (previouslyyjdHG) at 93.7 min on the calculated E. coli map. Inactivation of the dcuR anddcuS genes caused the loss of C4-dicarboxylate-stimulated synthesis of fumarate reductase (frdABCD genes) and of the anaerobic fumarate-succinate antiporter DcuB (dcuB gene). DcuS is predicted to contain a large periplasmic domain as the supposed site for C4-dicarboxylate sensing. Regulation by DcuR and DcuS responded to the presence of the C4-dicarboxylates fumarate, succinate, malate, aspartate, tartrate, and maleate. Since maleate is not taken up by the bacteria under these conditions, the carboxylates presumably act from without. Genes of the aerobic C4-dicarboxylate pathway encoding succinate dehydrogenase (sdhCDAB) and the aerobic succinate carrier (dctA) are only marginally or negatively regulated by the DcuSR system. The CitAB two-component regulatory system, which is highly similar to DcuSR, had no effect on C4-dicarboxylate regulation of any of the genes.

scholarly journals Exposure of a 23F Serotype Strain ofStreptococcus pneumoniaeto Cigarette Smoke Condensate Is Associated with Selective Upregulation of Genes Encoding the Two-Component Regulatory System 11 (TCS11)

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Riana Cockeran ◽  
Jenny A. Herbert ◽  
Timothy J. Mitchell ◽  
Thérèse Dix-Peek ◽  
Caroline Dickens ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Response Regulator ◽  
Expression Profiles ◽  
Regulatory System ◽  
Cigarette Smoke Condensate ◽  
Genome Expression ◽  
Two Component ◽  
Genes Encoding ◽  
Whole Genome Expression ◽  
Cognate Response Regulator

Alterations in whole genome expression profiles following exposure of the pneumococcus (strain 172, serotype 23F) to cigarette smoke condensate (160 μg/mL) for 15 and 60 min have been determined using the TIGR4 DNA microarray chip. Exposure to CSC resulted in the significant (P<0.014–0.0006) upregulation of the genes encoding the two-component regulatory system 11 (TCS11), consisting of the sensor kinase,hk11, and its cognate response regulator,rr11, in the setting of increased biofilm formation. These effects of cigarette smoke on the pneumococcus may contribute to colonization of the airways by this microbial pathogen.

scholarly journals RaxH/RaxR: A Two-Component Regulatory System in Xanthomonas oryzae pv. oryzae Required for AvrXa21 Activity

2004 ◽  
Vol 17 (6) ◽  
pp. 602-612 ◽  
Author(s):  
Saul Burdman ◽  
Yuwei Shen ◽  
Sang-Won Lee ◽  
Qinzhong Xue ◽  
Pamela Ronald
Keyword(s):  
Response Regulator ◽  
Sulfur Metabolism ◽  
Regulatory System ◽  
Xanthomonas Oryzae ◽  
Expression Vectors ◽  
Type I ◽  
Wild Type ◽  
Two Component ◽  
Genes Encoding ◽  
Null Mutants

Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight, one of the most serious diseases in rice. X. oryzae pv. oryzae Philippine race 6 (PR6) strains are unable to establish infection in rice lines expressing the resistance gene Xa21. Although the pathogen-associated molecule that triggers the Xa21-mediated defense response (AvrXa21) is unknown, six rax (required for AvrXa21 activity) genes encoding proteins involved in sulfur metabolism and Type I secretion were recently identified. Here, we report on the identification of two additional rax genes, raxR and raxH, which encode a response regulator and a histidine protein kinase of two-component regulatory systems, respectively. Null mutants of PR6 strain PXO99 that are impaired in either raxR, raxH, or both cause lesions significantly longer and grow to significantly higher levels than does the wild-type strain in Xa21-rice leaves. Both raxR and raxH mutants are complemented to wild-type levels of AvrXa21 activity by introduction of expression vectors carrying raxR and raxH, respectively. These null mutants do not affect AvrXa7 and AvrXa10 activities, as observed in inoculation experiments with Xa7- and Xa10-rice lines. Western blot and raxR/gfp promoter-reporter analyses confirmed RaxR expression in X. oryzae pv. oryzae. The results of promoter-reporter studies also suggest that the previously identified raxSTAB operon is a target for RaxH/RaxR regulation. Characterization of the RaxH/RaxR system provides new opportunities for understanding the specificity of the X. oryzae pv. oryzae-Xa21 interaction and may contribute to the identification of AvrXa21.

scholarly journals Global Analysis of Genes Regulated by EvgA of the Two-Component Regulatory System in Escherichia coli

2003 ◽  
Vol 185 (8) ◽  
pp. 2667-2672 ◽  
Author(s):  
Kunihiko Nishino ◽  
Yoshihiko Inazumi ◽  
Akihito Yamaguchi
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Response Regulator ◽  
Global Analysis ◽  
Regulatory System ◽  
Acid Resistance ◽  
Osmotic Adaptation ◽  
Multiple Genes ◽  
Two Component

ABSTRACT The response regulator EvgA controls expression of multiple genes conferring antibiotic resistance in Escherichia coli (K. Nishino and A. Yamaguchi, J. Bacteriol. 184:2319-2323, 2002). To understand the whole picture of EvgA regulation, DNA macroarray analysis of the effect of EvgA overproduction was performed. EvgA activated genes related to acid resistance, osmotic adaptation, and drug resistance.

scholarly journals Characterization of a Four-Component Regulatory System Controlling Bacteriocin Production in Streptococcus gallolyticus

mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexis Proutière ◽  
Laurence du Merle ◽  
Bruno Périchon ◽  
Hugo Varet ◽  
Myriam Gominet ◽  
...  
Keyword(s):  
Response Regulator ◽  
Regulatory System ◽  
Opportunistic Pathogen ◽  
Bacteriocin Production ◽  
Two Component System ◽  
Promoter Regions ◽  
Component System ◽  
Content Type ◽  
Streptococcus Gallolyticus ◽  
Two Component

ABSTRACT Bacteriocins are natural antimicrobial peptides produced by bacteria to kill closely related competitors. The opportunistic pathogen Streptococcus gallolyticus subsp. gallolyticus was recently shown to outcompete commensal enterococci of the murine microbiota under tumoral conditions thanks to the production of a two-peptide bacteriocin named gallocin. Here, we identified four genes involved in the regulatory control of gallocin in S. gallolyticus subsp. gallolyticus UCN34 that encode a histidine kinase/response regulator two-component system (BlpH/BlpR), a secreted peptide (GSP [gallocin-stimulating peptide]), and a putative regulator of unknown function (BlpS). While BlpR is a typical 243-amino-acid (aa) response regulator possessing a phospho-receiver domain and a LytTR DNA-binding domain, BlpS is a 108-aa protein containing only a LytTR domain. Our results showed that the secreted peptide GSP activates the dedicated two-component system BlpH/BlpR to induce gallocin transcription. A genome-wide transcriptome analysis indicates that this regulatory system (GSP-BlpH/BlpR) is specific for bacteriocin production. Importantly, as opposed to BlpR, BlpS was shown to repress gallocin gene transcription. A conserved operator DNA sequence of 30 bp was found in all promoter regions regulated by BlpR and BlpS. Electrophoretic mobility shift assays (EMSA) and footprint assays showed direct and specific binding of BlpS and BlpR to various regulated promoter regions in a dose-dependent manner on this conserved sequence. Gallocin expression appears to be tightly controlled in S. gallolyticus subsp. gallolyticus by quorum sensing and antagonistic activity of 2 LytTR-containing proteins. Competition experiments in gut microbiota medium and 5% CO2 to mimic intestinal conditions demonstrate that gallocin is functional under these in vivo-like conditions. IMPORTANCE Streptococcus gallolyticus subsp. gallolyticus, formerly known as Streptococcus bovis biotype I, is an opportunistic pathogen causing septicemia and endocarditis in the elderly often associated with asymptomatic colonic neoplasia. Recent studies indicate that S. gallolyticus subsp. gallolyticus is both a driver and a passenger of colorectal cancer. We previously showed that S. gallolyticus subsp. gallolyticus produces a bacteriocin, termed gallocin, enabling colonization of the colon under tumoral conditions by outcompeting commensal members of the murine microbiota such as Enterococcus faecalis. Here, we identified and extensively characterized a four-component system that regulates gallocin production. Gallocin gene transcription is activated by a secreted peptide pheromone (GSP) and a two-component signal transduction system composed of a transmembrane histidine kinase receptor (BlpH) and a cytosolic response regulator (BlpR). Finally, a DNA-binding protein (BlpS) was found to repress gallocin genes transcription, likely by antagonizing BlpR. Understanding gallocin regulation is crucial to prevent S. gallolyticus subsp. gallolyticus colon colonization under tumoral conditions.

Bacteriocin production in Streptococcus gallolyticus is controlled by a complex 4-component regulatory system with activator and anti-activator activities

2020 ◽  
Author(s):  
Alexis Proutière ◽  
Bruno Périchon ◽  
Laurence du Merle ◽  
Hugo Varet ◽  
Patrick Trieu-Cuot ◽  
...  
Keyword(s):  
Histidine Kinase ◽  
Response Regulator ◽  
Regulatory System ◽  
Opportunistic Pathogen ◽  
Bacteriocin Production ◽  
Two Component System ◽  
Promoter Regions ◽  
Component System ◽  
Streptococcus Gallolyticus ◽  
Two Component

AbstractBacteriocins are natural antimicrobial peptides produced by bacteria to kill closely related competitors. The opportunistic pathogen Streptococcus gallolyticus (Sgg) was recently shown to outcompete commensal enterococci of the murine microbiota in tumoral conditions thanks to the production of a two-peptide bacteriocin named gallocin. We here identified 4 genes involved in the regulatory control of gallocin in Sgg UCN34, respectively encoding a histidine kinase/response regulator two-component system (BlpH/BlpR), a secreted peptide (GSP), and a putative regulator of unknown function (BlpS). While BlpR is a typical 243-aa response regulator possessing a phospho-receiver domain and a LytTR DNA-binding domain, BlpS is a 108-aa protein containing only a LytTR domain. Our results showed that the secreted peptide GSP activates the dedicated two-component system BlpH/BlpR to induce gallocin transcription. A genome-wide transcriptome analysis indicates that this regulatory system (GSP-BlpH/BlpR) is highly specific for bacteriocin production. Importantly, as opposed to BlpR, BlpS was shown to repress gallocin gene transcription. A conserved operator DNA sequence of 30-bp was found in all promoter regions regulated by BlpR and BlpS. EMSA assays showed direct and specific binding of the two gallocin regulators to various regulated promoter regions in a dose dependent manner. Gallocin expression appears tightly controlled in Sgg by quorum sensing and antagonistic activity of 2 LytTR-containing proteins.SignificanceStreptococcus gallolyticus (Sgg), formely known as S. bovis biotype I, is an opportunistic pathogen causing septicemia and endocarditis in the elderly often associated with asymptomatic colonic neoplasia. We previously showed that Sgg produces a bacteriocin, termed gallocin, enabling colonization of the colon in tumoral conditions by outcompeting commensal members of the gut. Here we characterized a 4-component regulatory system that regulates gallocin transcription, which is activated by the response regulator BlpR. BlpR itself is activated by a quorum sensing peptide GSP and a dedicated histidine kinase BlpH. Interestingly, BlpS, a small DNA-binding protein co-transcribed with BlpR was found to repress gallocin genes transcription, likely by antagonizing BlpR. Understanding gallocin regulation is crucial to prevent Sgg colon colonization in tumoral conditions.

scholarly journals Identification of a Two-Component System Important for Cell Division of the Rice Pathogen Burkholderia glumae in Response to Nutrient Conditions

2021 ◽  
Author(s):  
Joan Marunga ◽  
Eunhye Goo ◽  
Yongsung Kang ◽  
Ingyu Hwang
Keyword(s):  
Cell Division ◽  
Response Regulator ◽  
Cell Formation ◽  
Luria Bertani ◽  
Dependent Manner ◽  
Two Component System ◽  
Promoter Regions ◽  
Burkholderia Glumae ◽  
Component System ◽  
Two Component

Abstract Bacterial two-component regulatory systems control the expression of sets of genes to coordinate physiological functions in response to environmental cues. Here, we report that a genetically linked but functionally unpaired two-component system comprising the sensor kinase GluS (BGLU_1G13350) and the response regulator GluR (BGLU_1G13360) is critical for cell division in the rice pathogen Burkholderia glumae BGR1. The gluR null mutant, unlike the gluS mutant, formed filamentous cells in Luria–Bertani medium and was sensitive to exposure to 42°C. Expression of genes responsible for cell division and cell-wall (dcw) biosynthesis in the gluR mutant was elevated compared to the wild type, resulting in an imbalance between FtsZ and FtsA. GluR-His bound to the putative promoter regions of ftsA and ftsZ, indicating that repression of genes in the dcw cluster by GluR is critical for cell division in B. glumae. The gluR mutant did not form filamentous cells in M9 minimal medium, whereas exogenous addition of glutamine or glutamate to the medium induced filamentous cell formation. These results implicate glutamine and glutamate as external stimuli that modulate GluR-mediated cell division in B. glumae. Therefore, GluR controls cell division of B. glumae in a nutrition-dependent manner.

scholarly journals A Two-Component Regulatory System, CsrR-CsrS, Represses Expression of Three Streptococcus pyogenesVirulence Factors, Hyaluronic Acid Capsule, Streptolysin S, and Pyrogenic Exotoxin B

1999 ◽  
Vol 67 (10) ◽  
pp. 5298-5305 ◽  
Author(s):  
Andrew Heath ◽  
Victor J. DiRita ◽  
Neil L. Barg ◽  
N. Cary Engleberg
Keyword(s):  
Virulence Factors ◽  
Response Regulator ◽  
Regulatory System ◽  
Skin Lesions ◽  
Wild Type ◽  
Gene Encoding ◽  
Streptolysin S ◽  
Two Component ◽  
Genes Encoding ◽  
Transposon Insertions

ABSTRACT Certain Tn916 insertions in the chromosome of an M1-type, nonmucoid Streptococcus pyogenes isolate (MGAS166) were previously shown to result in stable mucoidy with increased expression of the capsular synthetic genes. The transposon insertions in these strains are directly upstream of an apparent operon encoding a two-component regulatory system, designated csrR-csrS. Compared with MGAS166, these mucoid mutants are more hemolytic and cause significantly more tissue damage in a murine model of skin infection. To extend these observations, we constructed an in-frame deletion in the gene encoding the response regulator, csrR, and we evaluated the expression of other known S. pyogenesvirulence factors. We discovered that csrR mutants have enhanced transcription of sagA, a gene associated with streptolysin S (SLS) and speB, the gene encoding pyrogenic exotoxin B (SpeB). The mutants also express substantially higher SLS activity and SpeB antigen in late-exponential-phase cultures. There is no change in expression of emm, scpA,sic, or cpa (genes encoding other S. pyogenes virulence factors). CsrR− strains but not the wild-type parental strain produce necrotizing lesions in a mouse model of subcutaneous infection. A double mutant with deletions in bothcsrR and the capsular synthesis genes caused fewer and smaller necrotic skin lesions than the csrR mutants. However, this nonmucoid csrR strain was more likely than the wild type to yield necrotic lesions, suggesting that mucoidy contributes to virulence in this model of infection but that there are other csrR-regulated factors involved in the production of necrotic lesions.

Sign in / Sign up

Export Citation Format

Share Document