scholarly journals A Two-Component System (XydS/R) Controls the Expression of Genes Encoding CBM6-Containing Proteins in Response to Straw in Clostridium cellulolyticum

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e56063 ◽  
Author(s):  
Hamza Celik ◽  
Jean-Charles Blouzard ◽  
Birgit Voigt ◽  
Dörte Becher ◽  
Valentine Trotter ◽  
...  
Keyword(s):  
Two Component System ◽  
Component System ◽  
Clostridium Cellulolyticum ◽  
Expression Of Genes ◽  
Two Component ◽  
Genes Encoding

scholarly journals Reciprocal Regulation of Resistance-Nodulation-Division Efflux Systems and the Cpx Two-Component System in Vibrio cholerae

2014 ◽  
Vol 82 (7) ◽  
pp. 2980-2991 ◽  
Author(s):  
Dawn L. Taylor ◽  
X. Renee Bina ◽  
Leyla Slamti ◽  
Matthew K. Waldor ◽  
James E. Bina
Keyword(s):  
Antimicrobial Resistance ◽  
Vibrio Cholerae ◽  
Cell Envelope ◽  
Two Component System ◽  
Reciprocal Regulation ◽  
Component System ◽  
Content Type ◽  
Expression Of Genes ◽  
Two Component ◽  
Resistance Nodulation Division

ABSTRACTThe Cpx two-component regulatory system has been shown inEscherichia colito alleviate stress caused by misfolded cell envelope proteins. TheVibrio choleraeCpx system was previously found to respond to cues distinct from those in theE. colisystem, suggesting that this system fulfills a different physiological role in the cholera pathogen. Here, we used microarrays to identify genes that were regulated by theV. choleraeCpx system. Our observations suggest that the activation of theV. choleraeCpx system does not induce expression of genes involved in the mitigation of stress generated by misfolded cell envelope proteins but promotes expression of genes involved in antimicrobial resistance. In particular, activation of the Cpx system induced expression of the genes encoding the VexAB and VexGH resistance-nodulation-division (RND) efflux systems and their cognate outer membrane pore protein TolC. The promoters for these loci contained putative CpxR consensus binding sites, and ectopiccpxRexpression activated transcription from the promoters for the RND efflux systems. CpxR was not required for intrinsic antimicrobial resistance, but CpxR activation enhanced resistance to antimicrobial substrates of VexAB and VexGH. Mutations that inactivated VexAB or VexGH efflux activity resulted in the activation of the Cpx response, suggesting thatvexABandvexGHand thecpxP-cpxRAsystem are reciprocally regulated. We speculate that the reciprocal regulation of theV. choleraeRND efflux systems and the Cpx two-component system is mediated by the intracellular accumulation of an endogenously produced metabolic by-product that is normally extruded from the cell by the RND efflux systems.

scholarly journals The ChrA-ChrS and HrrA-HrrS Signal Transduction Systems Are Required for Activation of the hmuO Promoter and Repression of the hemA Promoter in Corynebacterium diphtheriae

2007 ◽  
Vol 75 (5) ◽  
pp. 2421-2431 ◽  
Author(s):  
Lori A. Bibb ◽  
Carey A. Kunkle ◽  
Michael P. Schmitt
Keyword(s):  
Corynebacterium Diphtheriae ◽  
Heme Iron ◽  
Dependent Manner ◽  
Two Component System ◽  
Component System ◽  
Regulatory Systems ◽  
Component Systems ◽  
Two Component ◽  
Genes Encoding ◽  
Two Component Systems

ABSTRACT Transcription of the Corynebacterium diphtheriae hmuO gene, which encodes a heme oxygenase involved in heme iron utilization, is activated in a heme- or hemoglobin-dependent manner in part by the two-component system ChrA-ChrS. Mutation of either the chrA or the chrS gene resulted in a marked reduction of hemoglobin-dependent activation at the hmuO promoter in C. diphtheriae; however, it was observed that significant levels of hemoglobin-dependent expression were maintained in the mutants, suggesting that an additional activator is involved in regulation. A BLAST search of the C. diphtheriae genome sequence revealed a second two-component system, encoded by DIP2268 and DIP2267, that shares similarity with ChrS and ChrA, respectively; we have designated these genes hrrS (DIP2268) and hrrA (DIP2267). Analysis of hmuO promoter expression demonstrated that hemoglobin-dependent activity was fully abolished in strains from which both the chrA-chrS and the hrrA-hrrS two-component systems were deleted. Similarly, deletion of the sensor kinase genes chrS and hrrS or the genes encoding both of the response regulators chrA and hrrA also eliminated hemoglobin-dependent activation at the hmuO promoter. We also show that the regulators ChrA-ChrS and HrrA-HrrS are involved in the hemoglobin-dependent repression of the promoter upstream of hemA, which encodes a heme biosynthesis enzyme. Evidence for cross talk between the ChrA-ChrS and HrrA-HrrS systems is presented. In conclusion, these findings demonstrate that the ChrA-ChrS and HrrA-HrrS regulatory systems are critical for full hemoglobin-dependent activation at the hmuO promoter and also suggest that these two-component systems are involved in the complex mechanism of the regulation of heme homeostasis in C. diphtheriae.

scholarly journals Expression of the genes encoding the CasK/R two-component system and the DesA desaturase duringBacillus cereuscold adaptation

2016 ◽  
Vol 363 (16) ◽  
pp. fnw174 ◽  
Author(s):  
Sara Esther Diomandé ◽  
Bénédicte Doublet ◽  
Florian Vasaï ◽  
Marie-Hélène Guinebretière ◽  
Véronique Broussolle ◽  
...  
Keyword(s):  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Genes Encoding

The regulator CdsS/CdsR two-component system modulates expression of genes involved in chitin degradation of Pseudoalteromonas piscicida strain O-7

2007 ◽  
Vol 188 (6) ◽  
pp. 619-628 ◽  
Author(s):  
Katsushiro Miyamoto ◽  
Mina Okunishi ◽  
Eiji Nukui ◽  
Takahiro Tsuchiya ◽  
Takeshi Kobayashi ◽  
...  
Keyword(s):  
Two Component System ◽  
Component System ◽  
Chitin Degradation ◽  
Expression Of Genes ◽  
Two Component

scholarly journals Specific Differentiation betweenMycobacterium bovis BCG and Virulent Strains of theMycobacterium tuberculosis Complex

1998 ◽  
Vol 36 (9) ◽  
pp. 2471-2476 ◽  
Author(s):  
Juana Magdalena ◽  
Philip Supply ◽  
Camille Locht
Keyword(s):  
The Other ◽  
Enzyme Linked Immunosorbent Assay ◽  
Oligonucleotide Probes ◽  
Two Component System ◽  
Tuberculosis Complex ◽  
Component System ◽  
Copy Numbers ◽  
Virulent Strains ◽  
Two Component ◽  
Genes Encoding

A PCR procedure based on the intergenic region (IR) separating two genes encoding a recently identified mycobacterial two-component system, named SenX3-RegX3, was developed and was shown to be suitable for identifying Mycobacterium bovis BCG. ThesenX3-regX3 IR contains a novel type of repetitive sequence, called mycobacterial interspersed repetitive units (MIRUs). All tested BCG strains exclusively contained 77-bp MIRUs within the senX3-regX3 IR, whereas all non-BCGM. tuberculosis complex strains contained a 53-bp MIRU, in addition to the 77-bp MIRUs. All 148 strains analyzed so far could be divided into eight different groups according to the copy numbers of the 77-bp MIRU and to the presence or absence of the 53-bp MIRU. BCG strains contained either one, two, or three 77-bp MIRUs. The other strains contained one to five 77-bp MIRUs invariably followed by a 53-bp MIRU. The consistent absence of the 53-bp MIRU in BCG strains and its presence in virulent strains allowed us to develop an enzyme-linked immunosorbent assay using specific capture oligonucleotide probes to distinguish between BCG and other M. tuberculosis complex strains.

scholarly journals Resistance to Colistin in Acinetobacter baumannii Associated with Mutations in the PmrAB Two-Component System

2009 ◽  
Vol 53 (9) ◽  
pp. 3628-3634 ◽  
Author(s):  
Mark D. Adams ◽  
Gabrielle C. Nickel ◽  
Saralee Bajaksouzian ◽  
Heather Lavender ◽  
A. Rekha Murthy ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Serial Passage ◽  
Multidrug Resistant ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Genes Encoding ◽  
Survival Assay ◽  
Derivatives Of

ABSTRACT The mechanism of colistin resistance (Colr) in Acinetobacter baumannii was studied by selecting in vitro Colr derivatives of the multidrug-resistant A. baumannii isolate AB0057 and the drug-susceptible strain ATCC 17978, using escalating concentrations of colistin in liquid culture. DNA sequencing identified mutations in genes encoding the two-component system proteins PmrA and/or PmrB in each strain and in a Colr clinical isolate. A colistin-susceptible revertant of one Colr mutant strain, obtained following serial passage in the absence of colistin selection, carried a partial deletion of pmrB. Growth of AB0057 and ATCC 17978 at pH 5.5 increased the colistin MIC and conferred protection from killing by colistin in a 1-hour survival assay. Growth in ferric chloride [Fe(III)] conferred a small protective effect. Expression of pmrA was increased in Colr mutants, but not at a low pH, suggesting that additional regulatory factors remain to be discovered.

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