Faculty Opinions recommendation of A cis-encoded antisense small RNA regulated by the HP0165-HP0166 two-component system controls expression of ureB in Helicobacter pylori.

2010 ◽  
Author(s):  
Vincenzo Scarlato ◽  
Alberto Danielli
Keyword(s):  
Helicobacter Pylori ◽  
Small Rna ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Involvement of the HP0165-HP0166 Two-Component System in Expression of Some Acidic-pH-Upregulated Genes of Helicobacter pylori

2006 ◽  
Vol 188 (5) ◽  
pp. 1750-1761 ◽  
Author(s):  
Yi Wen ◽  
Jing Feng ◽  
David R. Scott ◽  
Elizabeth A. Marcus ◽  
George Sachs
Keyword(s):  
Helicobacter Pylori ◽  
Sequence Similarity ◽  
Low Ph ◽  
Ph Sensitive ◽  
Cytoplasmic Ph ◽  
Two Component System ◽  
Mobility Shift ◽  
Component System ◽  
Two Component

ABSTRACT About 200 genes of the gastric pathogen Helicobacter pylori increase expression at medium pHs of 6.2, 5.5, and 4.5, an increase that is abolished or much reduced by the buffering action of urease. Genes up-regulated by a low pH include the two-component system HP0165-HP0166, suggesting a role in the regulation of some of the pH-sensitive genes. To identify targets of HP0165-HP0166, the promoter regions of genes up-regulated by a low pH were grouped based on sequence similarity. Probes for promoter sequences representing each group were subjected to electrophoretic mobility shift assays (EMSA) with recombinant HP0166-His6 or a mutated response regulator, HP0166-D52N-His6, that can specifically determine the role of phosphorylation of HP0166 in binding (including a control EMSA with in-vitro-phosphorylated HP0166-His6). Nineteen of 45 promoter-regulatory regions were found to interact with HP0166-His6. Seven promoters for genes encoding α-carbonic anhydrase, omp11, fecD, lpp20, hypA, and two with unknown function (pHP1397-1396 and pHP0654-0675) were clustered in gene group A, which may respond to changes in the periplasmic pH at a constant cytoplasmic pH and showed phosphorylation-dependent binding in EMSA with HP0166-D52N-His6. Twelve promoters were clustered in groups B and C whose up-regulation likely also depends on a reduction of the cytoplasmic pH at a medium pH of 5.5 or 4.5. Most of the target promoters in groups B and C showed phosphorylation-dependent binding with HP0166-D52N-His6, but promoters for ompR (pHP0166-0162), pHP0682-0681, and pHP1288-1289 showed phosphorylation-independent binding. These findings, combined with DNase I footprinting, suggest that HP0165-0166 is an acid-responsive signaling system affecting the expression of pH-sensitive genes. Regulation of these genes responds either to a decrease in the periplasmic pH alone (HP0165 dependent) or also to a decrease in the cytoplasmic pH (HP0165 independent).

scholarly journals Delineation of the pH-responsive regulon controlled by the Helicobacter pylori ArsRS two- component system

2021 ◽  
Author(s):  
John T. Loh ◽  
Miranda V. Shum ◽  
Scott D.R. Jossart ◽  
Anne M. Campbell ◽  
Neha Sawhney ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Differentially Expressed ◽  
Sensor Kinase ◽  
Ph Responsive ◽  
Two Component System ◽  
Component System ◽  
Wide Range ◽  
Two Component ◽  
H Pylori

Helicobacter pylori encounters a wide range of pH within the human stomach. In a comparison of H. pylori cultured in vitro under neutral or acidic conditions, about 15% of genes are differentially expressed, and corresponding changes are detectable for many of the encoded proteins. The ArsRS two-component system (TCS), comprised of the sensor kinase ArsS and its cognate response regulator ArsR, has an important role in mediating pH-responsive changes in H. pylori gene expression. In this study, we sought to delineate the pH-responsive ArsRS regulon and further define the role of ArsR in pH-responsive gene expression. We compared H. pylori strains containing an intact ArsRS system with an arsS null mutant or strains containing site-specific mutations of a conserved aspartate residue (D52) in ArsR, which is phosphorylated in response to signals relayed by the cognate sensor kinase ArsS. We identified 178 genes that were pH-responsive in strains containing an intact ArsRS system but not in ΔarsS or arsR mutants. These constituents of the pH-responsive ArsRS regulon include genes involved in acid acclimatization (ureAB, amidases), oxidative stress responses (katA, sodB), transcriptional regulation related to iron or nickel homeostasis (fur, nikR), and genes encoding outer membrane proteins [including sabA, alpA, alpB, hopD (labA), and horA]. When comparing H. pylori strains containing an intact ArsRS TCS with arsRS mutants, each cultured at neutral pH, relatively few genes are differentially expressed. Collectively, these data suggest that ArsRS-mediated gene regulation has an important role in H. pylori adaptation to changing pH conditions.

scholarly journals Determinants of the regulation of Helicobacter pylori adhesins include repeat sequences in both promoter and coding regions as well as the two-component system ArsRS

2017 ◽  
Vol 66 (6) ◽  
pp. 798-807 ◽  
Author(s):  
Catherine R. Acio-Pizzarello ◽  
Abigail A. Acio ◽  
Edward J. Choi ◽  
Kimberly Bond ◽  
June Kim ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Two Component System ◽  
Component System ◽  
Coding Regions ◽  
Repeat Sequences ◽  
Two Component

scholarly journals Acid-Induced Activation of the Urease Promoters Is Mediated Directly by the ArsRS Two-Component System of Helicobacter pylori

2005 ◽  
Vol 73 (10) ◽  
pp. 6437-6445 ◽  
Author(s):  
Michael Pflock ◽  
Simone Kennard ◽  
Isabel Delany ◽  
Vincenzo Scarlato ◽  
Dagmar Beier
Keyword(s):  
Helicobacter Pylori ◽  
Binding Sites ◽  
Response Regulator ◽  
Two Component System ◽  
Component System ◽  
Nickel Ions ◽  
Colonization Factor ◽  
Two Component ◽  
Ph Conditions ◽  
Responsive Regulation

ABSTRACT The nickel-containing enzyme urease is an essential colonization factor of the human gastric pathogen Helicobacter pylori which enables the bacteria to survive the low-pH conditions of the stomach. Transcription of the urease genes is positively controlled in response to increasing concentrations of nickel ions and acidic pH. Here we demonstrate that acid-induced transcription of the urease genes is mediated directly by the ArsRS two-component system. Footprint analyses identify binding sites of the phosphorylated ArsR response regulator within the ureA and ureI promoters. Furthermore, deletion of a distal upstream ArsR binding site of the ureA promoter demonstrates its role in acid-dependent activation of the promoter. In addition, acid-induced transcription of the ureA gene is unaltered in a nikR mutant, providing evidence that pH-responsive regulation and nickel-responsive regulation of the ureA promoter are mediated by independent mechanisms involving the ArsR response regulator and the NikR protein.

scholarly journals The QseEF Two-Component System-GlmY Small RNA Regulatory Pathway Controls Swarming in Uropathogenic Proteus mirabilis

2022 ◽  
Vol 23 (1) ◽  
pp. 487
Author(s):  
Wen-Yuan Lin ◽  
Yuan-Ju Lee ◽  
Ping-Hung Yu ◽  
Yi-Lin Tsai ◽  
Pin-Yi She ◽  
...  
Keyword(s):  
Small Rna ◽  
Proteus Mirabilis ◽  
Promoter Activity ◽  
Mrna Level ◽  
Site Directed Mutagenesis ◽  
Dependent Manner ◽  
Two Component System ◽  
Swarming Motility ◽  
Component System ◽  
Two Component

Bacterial sensing of environmental signals through the two-component system (TCS) plays a key role in modulating virulence. In the search for the host hormone-sensing TCS, we identified a conserved qseEGF locus following glmY, a small RNA (sRNA) gene in uropathogenic Proteus mirabilis. Genes of glmY-qseE-qseG-qseF constitute an operon, and QseF binding sites were found in the glmY promoter region. Deletion of glmY or qseF resulted in reduced swarming motility and swarming-related phenotypes relative to the wild-type and the respective complemented strains. The qseF mutant had decreased glmYqseEGF promoter activity. Both glmY and qseF mutants exhibited decreased flhDC promoter activity and mRNA level, while increased rcsB mRNA level was observed in both mutants. Prediction by TargetRNA2 revealed cheA as the target of GlmY. Then, construction of the translational fusions containing various lengths of cheA 5′UTR for reporter assay and site-directed mutagenesis were performed to investigate the cheA-GlmY interaction in cheA activation. Notably, loss of glmY reduced the cheA mRNA level, and urea could inhibit swarming in a QseF-dependent manner. Altogether, this is the first report elucidating the underlying mechanisms for modulation of swarming motility by a QseEF-regulated sRNA GlmY, involving expression of cheA, rcsB and flhDC in uropathogenic P. mirabilis.

scholarly journals Identification of Target Genes Regulated by the Two-Component System HP166-HP165 of Helicobacter pylori

2002 ◽  
Vol 184 (2) ◽  
pp. 350-362 ◽  
Author(s):  
Patricia Dietz ◽  
Gabriele Gerlach ◽  
Dagmar Beier
Keyword(s):  
Helicobacter Pylori ◽  
Target Genes ◽  
Essential Gene ◽  
Response Regulator ◽  
Transcriptional Level ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
H Pylori ◽  
Target Promoters

ABSTRACT Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. In most cases regulation is accomplished on the transcriptional level by a response regulator protein, which, according to the phosphorylation state of its receiver domain, displays different affinities for its target promoters. Here we describe identification of genes regulated by the two-component system HP166-HP165 of Helicobacter pylori and characterization of the corresponding target promoters. We demonstrated that expression of the HP166-HP165 two-component system is negatively autoregulated under conditions favoring autophosphorylation of the histidine kinase. Furthermore, we found that response regulator HP166 activates transcription of genes encoding a protein family with an unknown function present in H. pylori 26695, as well as an operon composed of five H. pylori-specific genes. While open reading frame HP166 is an essential gene, the target genes of the response regulator are not required for growth under in vitro culture conditions.

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