scholarly journals The essential YycFG two-component system controls cell wall metabolism inBacillus subtilis

2007 ◽  
Vol 65 (1) ◽  
pp. 180-200 ◽  
Author(s):  
Paola Bisicchia ◽  
David Noone ◽  
Efthimia Lioliou ◽  
Alistair Howell ◽  
Sarah Quigley ◽  
...  
Keyword(s):  
Cell Wall ◽  
Two Component System ◽  
Cell Wall Metabolism ◽  
Component System ◽  
Two Component

scholarly journals Cell envelope gene expression in phosphate-limited Bacillus subtilis cells

Microbiology ◽  
2011 ◽  
Vol 157 (9) ◽  
pp. 2470-2484 ◽  
Author(s):  
Eric Botella ◽  
Sebastian Hübner ◽  
Karsten Hokamp ◽  
Annette Hansen ◽  
Paola Bisicchia ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cell Envelope ◽  
Expression Profiles ◽  
Phosphate Limitation ◽  
Envelope Gene ◽  
Two Component System ◽  
Cell Wall Metabolism ◽  
Component System ◽  
Two Component

The high phosphate content of Bacillus subtilis cell walls dictates that cell wall metabolism is an important feature of the PhoPR-mediated phosphate limitation response. Here we report the expression profiles of cell-envelope-associated and PhoPR regulon genes, determined by live cell array and transcriptome analysis, in exponentially growing and phosphate-limited B. subtilis cells. Control by the WalRK two-component system confers a unique expression profile and high level of promoter activity on the genes of its regulon with yocH and cwlO expression differing both qualitatively and quantitatively from all other autolysin-encoding genes examined. The activity of the PhoPR two-component system is restricted to the phosphate-limited state, being rapidly induced in response to the cognate stimulus, and can be sustained for an extended phosphate limitation period. Constituent promoters of the PhoPR regulon show heterogeneous induction profiles and very high promoter activities. Phosphate-limited cells also show elevated expression of the actin-like protein MreBH and reduced expression of the WapA cell wall protein and WprA cell wall protease indicating that cell wall metabolism in this state is distinct from that of exponentially growing and stationary-phase cells. The PhoPR response is very rapidly deactivated upon removal of the phosphate limitation stimulus with concomitant increased expression of cell wall metabolic genes. Moreover expression of genes encoding enzymes involved in sulphur metabolism is significantly altered in the phosphate-limited state with distinct perturbations being observed in wild-type 168 and AH024 (ΔphoPR) cells.

scholarly journals Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Stephanie L. Kellogg ◽  
Jaime L. Little ◽  
Jessica S. Hoff ◽  
Christopher J. Kristich
Keyword(s):  
Cell Wall ◽  
Enterococcus Faecium ◽  
Wall Stress ◽  
Signaling System ◽  
Beta Lactam ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Cell Wall Stress ◽  
Two Component

ABSTRACT Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis. Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis. Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis, exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium. Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci.

scholarly journals Two-component system VraSR positively modulates the regulation of cell-wall biosynthesis pathway in Staphylococcus aureus

2004 ◽  
Vol 49 (3) ◽  
pp. 807-821 ◽  
Author(s):  
Makoto Kuroda ◽  
Hiroko Kuroda ◽  
Taku Oshima ◽  
Fumihiko Takeuchi ◽  
Hirotada Mori ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Wall Biosynthesis ◽  
Biosynthesis Pathway ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Loss of Bacterial Cell Pole Stabilization in Caulobacter crescentus Sensitizes to Outer Membrane Stress and Peptidoglycan-Directed Antibiotics

2019 ◽  
Author(s):  
Simon-Ulysse Vallet ◽  
Lykke Haastrup Hansen ◽  
Freja Cecillie Bistrup ◽  
Julien Bortoli Chapalay ◽  
Marc Chambon ◽  
...  
Keyword(s):  
Cell Wall ◽  
Caulobacter Crescentus ◽  
Cell Envelope ◽  
Wall Stress ◽  
Two Component System ◽  
Component System ◽  
Division Plane ◽  
Cell Wall Stress ◽  
Two Component ◽  
Weak Points

AbstractRod-shaped bacteria frequently localise proteins to one or both cell poles in order to regulate processes such as chromosome replication or polar organelle development. However, the role of such polar factors in responses to extracellular stimuli has been generally unexplored. We employed chemical-genetic screening to probe the interaction between one such factor from Caulobacter crescentus, TipN, and extracellular stress and found that TipN is required for normal tolerance of cell envelope-directed antibiotics, including vancomycin that does not normally inhibit growth of Gram-negative bacteria. Forward genetic screening for suppressors of vancomycin sensitivity in the absence of TipN revealed the TonB-dependent receptor ChvT as the mediator of vancomycin tolerance. Loss of ChvT improved resistance to vancomycin and cefixime in the otherwise sensitive ΔtipN strain. The activity of the two-component system regulating ChvT (ChvIG) was increased in ΔtipN cells relative to wild type under some, but not all, cell wall stress conditions that this strain was sensitised to, in particular cefixime and detergent exposure. Together, these results indicate that the ChvIG two-component system has been co-opted as a sensor of cell wall stress and that TipN can influence cell envelope stability and ChvIG-mediated signaling in addition to its roles in intracellular development.Author summaryMaintenance of an intact cell envelope is essential for free-living bacteria to survive harsh conditions they may encounter in their environment. In the case of rod-shaped bacteria, the poles of the cell are potential weak points in the cell envelope due to the high curvature of the layers and the need to break and re-form parts of the cell envelope at the division plane in order to form new poles as the cells replicate and divide. We have found that TipN, a factor required for correct division and cell pole development in the rod-shaped bacterium, Caulobacter crescentus, is also needed for maintaining normal levels of resistance to cell wall-targeting antibiotics such as vancomycin and cefixime, which interfere with peptidoglycan synthesis. We also identified an outer membrane receptor, ChvT, that was responsible for allowing vancomycin access to the cells and found that the two-component system that negatively regulates ChvT production was activated by various kinds of cell wall stress. Presence or absence of TipN influenced how active this system was in the presence of cefixime or of the membrane-disrupting detergent sodium deoxycholate. Since TipN is normally located at the poles of the cell and at the division plane just before cells complete division, our results suggest that it is involved in stabilisation of these weak points of the cell envelope as well as its other roles inside the cell.

scholarly journals The Two-Component System CesRK Controls the Transcriptional Induction of Cell Envelope-Related Genes in Listeria monocytogenes in Response to Cell Wall-Acting Antibiotics

2008 ◽  
Vol 190 (13) ◽  
pp. 4772-4776 ◽  
Author(s):  
Sanne Gottschalk ◽  
Iver Bygebjerg-Hove ◽  
Mette Bonde ◽  
Pia Kiil Nielsen ◽  
Thanh Ha Nguyen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Cell Envelope ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Transcriptional Induction ◽  
Damaging Effects

ABSTRACT The two-component system CesRK of Listeria monocytogenes responds to cell wall-acting antibiotics. We show here that CesRK controls the transcription of several cell envelope-related genes. The CesRK-dependent induction of these genes may be viewed as an attempt by L. monocytogenes to protect itself against the damaging effects of cell wall-acting antibiotics.

scholarly journals YycH and YycI Interact To Regulate the Essential YycFG Two-Component System in Bacillus subtilis

2007 ◽  
Vol 189 (8) ◽  
pp. 3280-3289 ◽  
Author(s):  
Hendrik Szurmant ◽  
Michael A. Mohan ◽  
P. Michael Imus ◽  
James A. Hoch
Keyword(s):  
Signal Transduction ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Membrane Integrity ◽  
Direct Result ◽  
Signal Transduction System ◽  
Two Component System ◽  
Component System ◽  
Growth Defects ◽  
Two Component

ABSTRACT The YycFG two-component system is the only signal transduction system in Bacillus subtilis known to be essential for cell viability. This system is highly conserved in low-G+C gram-positive bacteria, regulating important processes such as cell wall homeostasis, cell membrane integrity, and cell division. Four other genes, yycHIJK, are organized within the same operon with yycF and yycG in B. subtilis. Recently, it was shown that the product of one of these genes, the YycH protein, regulated the activity of this signal transduction system, whereas no function could be assigned to the other genes. Results presented here show that YycI and YycH proteins interact to control the activity of the YycG kinase. Strains carrying individual in-frame deletion of the yycI and yycH coding sequences were constructed and showed identical phenotypes, namely a 10-fold-elevated expression of the YycF-dependent gene yocH, growth defects, as well as a cell wall defect. Cell wall and growth defects were a direct result of overregulation of the YycF regulon, since a strain overexpressing YycF showed phenotypes similar to those of yycH and yycI deletion strains. Both YycI and YycH proteins are localized outside the cytoplasm and attached to the membrane by an N-terminal transmembrane sequence. Bacterial two-hybrid data showed that the YycH, YycI, and the kinase YycG form a ternary complex. The data suggest that YycH and YycI control the activity of YycG in the periplasm and that this control is crucial in regulating important cellular processes.

scholarly journals Two-Component System VicRK Regulates Functions Associated with Establishment of Streptococcus sanguinis in Biofilms

2014 ◽  
Vol 82 (12) ◽  
pp. 4941-4951 ◽  
Author(s):  
Julianna J. Moraes ◽  
Rafael N. Stipp ◽  
Erika N. Harth-Chu ◽  
Tarsila M. Camargo ◽  
José F. Höfling ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biofilm Formation ◽  
Extracellular Dna ◽  
Aerobic Growth ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Streptococcus Sanguinis ◽  
Hydrolytic Activities ◽  
Two Component

ABSTRACTStreptococcus sanguinisis a commensal pioneer colonizer of teeth and an opportunistic pathogen of infectious endocarditis. The establishment ofS. sanguinisin host sites likely requires dynamic fitting of the cell wall in response to local stimuli. In this study, we investigated the two-component system (TCS) VicRK inS. sanguinis(VicRKSs), which regulates genes of cell wall biogenesis, biofilm formation, and virulence in opportunistic pathogens. AvicKknockout mutant obtained from strain SK36 (SKvic) showed slight reductions in aerobic growth and resistance to oxidative stress but an impaired ability to form biofilms, a phenotype restored in the complemented mutant. The biofilm-defective phenotype was associated with reduced amounts of extracellular DNA during aerobic growth, with reduced production of H2O2, a metabolic product associated with DNA release, and with inhibitory capacity ofS. sanguiniscompetitor species. No changes in autolysis or cell surface hydrophobicity were detected in SKvic. Reverse transcription-quantitative PCR (RT-qPCR), electrophoretic mobility shift assays (EMSA), and promoter sequence analyses revealed that VicR directly regulates genes encoding murein hydrolases (SSA_0094,cwdP, andgbpB) andspxB, which encodes pyruvate oxidase for H2O2production. Genes previously associated withspxBexpression (spxR,ccpA,ackA, andtpK) were not transcriptionally affected in SKvic. RT-qPCR analyses ofS. sanguinisbiofilm cells further showed upregulation of VicRK targets (spxB,gbpB, andSSA_0094) and other genes for biofilm formation (gtfPandcomE) compared to expression in planktonic cells. This study provides evidence that VicRKSsregulates functions crucial forS. sanguinisestablishment in biofilms and identifies novel VicRK targets potentially involved in hydrolytic activities of the cell wall required for these functions.

scholarly journals YycH Regulates the Activity of the Essential YycFG Two-Component System in Bacillus subtilis

2005 ◽  
Vol 187 (15) ◽  
pp. 5419-5426 ◽  
Author(s):  
Hendrik Szurmant ◽  
Kristine Nelson ◽  
Eun-Ja Kim ◽  
Marta Perego ◽  
James A. Hoch
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Histidine Kinase ◽  
Response Regulator ◽  
Temperature Sensitive ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Regulated Gene Expression

ABSTRACT Of the numerous two-component signal transduction systems found in bacteria, only a very few have proven to be essential for cell viability. Among these is the YycF (response regulator)-YycG (histidine kinase) system, which is highly conserved in and specific to the low-G+C content gram-positive bacteria. Given the pathogenic nature of several members of this class of bacteria, the YycF-YycG system has been suggested as a prime antimicrobial target. In an attempt to identify genes involved in regulation of this two-component system, a transposon mutagenesis study was designed to identify suppressors of a temperature-sensitive YycF mutant in Bacillus subtilis. Suppressors could be identified, and the prime target was the yycH gene located adjacent to yycG and within the same operon. A lacZ reporter assay revealed that YycF-regulated gene expression was elevated in a yycH strain, whereas disruption of any of the three downstream genes within the operon, yycI, yycJ, and yycK, showed no such effect. The concentrations of both YycG and YycF, assayed immunologically, remained unchanged between the wild-type and the yycH strain as determined by immunoassay. Alkaline phosphatase fusion studies showed that YycH is located external to the cell membrane, suggesting that it acts in the regulation of the sensor domain of the YycG sensor histidine kinase. The yycH strain showed a characteristic cell wall defect consistent with the previously suggested notion that the YycF-YycG system is involved in regulating cell wall homeostasis and indicating that either up- or down-regulation of YycF activity affects this homeostatic mechanism.

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