Faculty Opinions recommendation of The HP0165-HP0166 two-component system (ArsRS) regulates acid-induced expression of HP1186 alpha-carbonic anhydrase in Helicobacter pylori by activating the pH-dependent promoter.

2007 ◽  
Author(s):  
Gene Nester
Keyword(s):  
Helicobacter Pylori ◽  
Carbonic Anhydrase ◽  
Two Component System ◽  
Induced Expression ◽  
Component System ◽  
Two Component ◽  
Ph Dependent

scholarly journals The HP0165-HP0166 Two-Component System (ArsRS) Regulates Acid-Induced Expression of HP1186 α-Carbonic Anhydrase in Helicobacter pylori by Activating the pH-Dependent Promoter

2007 ◽  
Vol 189 (6) ◽  
pp. 2426-2434 ◽  
Author(s):  
Yi Wen ◽  
Jing Feng ◽  
David R. Scott ◽  
Elizabeth A. Marcus ◽  
George Sachs
Keyword(s):  
Carbonic Anhydrase ◽  
Promoter Region ◽  
Low Ph ◽  
Start Codon ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Ph Dependent ◽  
H Pylori

ABSTRACT The periplasmic α-carbonic anhydrase of Helicobacter pylori is essential for buffering the periplasm at acidic pH. This enzyme is an integral component of the acid acclimation response that allows this neutralophile to colonize the stomach. Transcription of the HP1186 α-carbonic anhydrase gene is upregulated in response to low environmental pH. A binding site for the HP0166 response regulator (ArsR) has been identified in the promoter region of the HP1186 gene. To investigate the mechanism that regulates the expression of HP1186 in response to low pH and the role of the HP0165-HP0166 two-component system (ArsRS) in this acid-inducible regulation, Northern blot analysis was performed with RNAs isolated from two different wild-type H. pylori strains (26695 and 43504) and mutants with HP0165 histidine kinase (ArsS) deletions, after exposure to either neutral pH or low pH (pH 4.5). ArsS-dependent upregulation of HP1186 α-carbonic anhydrase in response to low pH was found in both strains. Western blot analysis of H. pylori membrane proteins confirmed the regulatory role of ArsS in HP1186 expression in response to low pH. Analysis of the HP1186 promoter region revealed two possible transcription start points (TSP1 and TSP2) located 43 and 11 bp 5′ of the ATG start codon, respectively, suggesting that there are two promoters transcribing the HP1186 gene. Quantitative primer extension analysis showed that the promoter from TSP1 (43 bp 5′ of the ATG start codon) is a pH-dependent promoter and is regulated by ArsRS in combating environmental acidity, whereas the promoter from TSP2 may be responsible for control of the basal transcription of HP1186 α-carbonic anhydrase.

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 Prevention of Surface-Associated Calcium Phosphate by thePseudomonas syringaeTwo-Component System CvsSR

2019 ◽  
Vol 201 (7) ◽  
Author(s):  
Maxwell R. Fishman ◽  
Melanie J. Filiatrault
Keyword(s):  
Calcium Phosphate ◽  
Carbonic Anhydrase ◽  
Pseudomonas Syringae ◽  
Dependent Manner ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Two Component ◽  
Calcium Phosphate Precipitation ◽  
Calcium Precipitation

ABSTRACTCvsSR is a Ca2+-induced two-component system (TCS) in the plant pathogenPseudomonas syringaepv. tomato DC3000. Here, we discovered that CvsSR is induced by Fe3+, Zn2+, and Cd2+. However, only supplementation of Ca2+to medium resulted in rugose, opaque colonies in ΔcvsSand ΔcvsRstrains. This phenotype corresponded to formation of calcium phosphate precipitation on the surface of ΔcvsSand ΔcvsRcolonies. CvsSR regulated swarming motility inP. syringaepv. tomato in a Ca2+-dependent manner, but swarming behavior was not influenced by Fe3+, Zn2+, or Cd2+. We hypothesized that reduced swarming displayed by ΔcvsSand ΔcvsRstrains was due to precipitation of calcium phosphate on the surface of ΔcvsSand ΔcvsRcells grown on agar medium supplemented with Ca2+. By reducing the initial pH or adding glucose to the medium, calcium precipitation was inhibited, and swarming was restored to ΔcvsSand ΔcvsRstrains, suggesting that calcium precipitation influences swarming ability. Constitutive expression of a CvsSR-regulated carbonic anhydrase and a CvsSR-regulated putative sulfate major facilitator superfamily transporter in ΔcvsSand ΔcvsRstrains inhibited formation of calcium precipitates and restored the ability of ΔcvsSand ΔcvsRbacteria to swarm. Lastly, we found that glucose inhibited Ca2+-based induction of CvsSR. Hence, CvsSR is a key regulator that controls calcium precipitation on the surface of bacterial cells.IMPORTANCEBacteria are capable of precipitating and dissolving minerals. We previously reported the characterization of the two-component system CvsSR in the plant-pathogenic bacteriumPseudomonas syringae. CvsSR responds to the presence of calcium and is important for causing disease. Here, we show that CvsSR controls the ability of the bacterium to prevent calcium phosphate precipitation on the surface of cells. We also identified a carbonic anhydrase and transporter that modulate formation of surface-associated calcium precipitates. Furthermore, our results demonstrate that the ability of the bacterium to swarm is controlled by the formation and dissolution of calcium precipitates on the surface of cells. Our study describes new mechanisms for microbially induced mineralization and provides insights into the role of mineral deposits on bacterial physiology. The discoveries may lead to new technological and environmental applications.

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