scholarly journals The AauR-AauS Two-Component System Regulates Uptake and Metabolism of Acidic Amino Acids in Pseudomonas putida

2006 ◽  
Vol 72 (10) ◽  
pp. 6569-6577 ◽  
Author(s):  
Avinash M. Sonawane ◽  
Birendra Singh ◽  
Klaus-Heinrich Röhm
Keyword(s):  
Amino Acids ◽  
Pseudomonas Putida ◽  
Transcriptional Analysis ◽  
Two Component System ◽  
Component System ◽  
Carbon And Nitrogen ◽  
Acidic Amino Acids ◽  
Wide Range ◽  
Two Component ◽  
Uptake And Metabolism

ABSTRACT Pseudomonas putida KT2440 metabolizes a wide range of carbon and nitrogen sources, including many amino acids. In this study, a σ54-dependent two-component system that controls the uptake and metabolism of acidic amino acids was identified. The system (designated aau, for acidic amino acid utilization) involves a sensor histidine kinase, AauS, encoded by PP1067, and a response regulator, AauR, encoded by PP1066. aauR and aauS deletion mutants were unable to efficiently utilize aspartate (Asp), glutamate (Glu), and glutamine (Gln) as sole sources of carbon and nitrogen. Growth of the mutants was partially restored when the above-mentioned amino acids were supplemented with glucose or succinate as an additional carbon source. Uptake of Gln, Asp, and asparagine (Asn) by the aauR mutant was moderately reduced, while Glu uptake was severely impaired. In the absence of glucose, the aauR mutant even secreted Glu into the medium. Furthermore, disruption of aauR affected the activities of several key enzymes of Glu and Asp metabolism, leading to the intracellular accumulation of Glu and greatly reduced survival times under conditions of nitrogen starvation. By a proteomics approach, four major proteins were identified that are downregulated during growth of the aauR mutant on Glu. Two of these were identified as periplasmic glutaminase/asparaginase and the solute-binding protein of a Glu/Asp transporter. Transcriptional analysis of lacZ fusions containing the putative promoter regions of these genes confirmed that their expression is indeed affected by the aau system. Three further periplasmic solute-binding proteins were strongly expressed during growth of the aauR deletion mutant on Glu but downregulated during cultivation on glucose/NH4 +. These systems may be involved in amino acid efflux.

scholarly journals A Two-Component Regulatory System Integrates Redox State and Population Density Sensing in Pseudomonas putida

2008 ◽  
Vol 190 (23) ◽  
pp. 7666-7674 ◽  
Author(s):  
Regina Fernández-Piñar ◽  
Juan Luis Ramos ◽  
José Juan Rodríguez-Herva ◽  
Manuel Espinosa-Urgel
Keyword(s):  
Pseudomonas Putida ◽  
Cytochrome Oxidase ◽  
Cell Density ◽  
Bacterial Colonization ◽  
Regulatory Element ◽  
Regulatory System ◽  
Transcriptional Analysis ◽  
Two Component System ◽  
Component System ◽  
Two Component

ABSTRACT A two-component system formed by a sensor histidine kinase and a response regulator has been identified as an element participating in cell density signal transduction in Pseudomonas putida KT2440. It is a homolog of the Pseudomonas aeruginosa RoxS/RoxR system, which in turn belongs to the RegA/RegB family, described in photosynthetic bacteria as a key regulatory element. In KT2440, the two components are encoded by PP_0887 (roxS) and PP_0888 (roxR), which are transcribed in a single unit. Characterization of this two-component system has revealed its implication in redox signaling and cytochrome oxidase activity, as well as in expression of the cell density-dependent gene ddcA, involved in bacterial colonization of plant surfaces. Whole-genome transcriptional analysis has been performed to define the P. putida RoxS/RoxR regulon. It includes genes involved in sugar and amino acid metabolism and the sulfur starvation response and elements of the respiratory chain (a cbb3 cytochrome oxidase, Fe-S clusters, and cytochrome c-related proteins) or genes participating in the maintenance of the redox balance. A putative RoxR recognition element containing a conserved hexamer (TGCCAG) has also been identified in promoters of genes regulated by this two-component system.

Engineering Escherichia coli to sense acidic amino acids by introduction of a chimeric two-component system

2015 ◽  
Vol 32 (10) ◽  
pp. 2073-2077 ◽  
Author(s):  
Sambandam Ravikumar ◽  
Irisappan Ganesh ◽  
Murali Kannan Maruthamuthu ◽  
Soon Ho Hong
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Two Component System ◽  
Component System ◽  
Acidic Amino Acids ◽  
Two Component

scholarly journals Kinetic Characterization of the WalRKSpn (VicRK) Two-Component System of Streptococcus pneumoniae: Dependence of WalKSpn (VicK) Phosphatase Activity on Its PAS Domain

2010 ◽  
Vol 192 (9) ◽  
pp. 2346-2358 ◽  
Author(s):  
Alina D. Gutu ◽  
Kyle J. Wayne ◽  
Lok-To Sham ◽  
Malcolm E. Winkler
Keyword(s):  
Amino Acids ◽  
Streptococcus Pneumoniae ◽  
Phosphatase Activity ◽  
Pas Domain ◽  
Kinetic Characterization ◽  
Two Component System ◽  
Histidine Kinases ◽  
Component System ◽  
Two Component

ABSTRACT The WalRK two-component system plays important roles in maintaining cell wall homeostasis and responding to antibiotic stress in low-GC Gram-positive bacteria. In the major human pathogen, Streptococcus pneumoniae, phosphorylated WalR Spn (VicR) response regulator positively controls the transcription of genes encoding the essential PcsB division protein and surface virulence factors. WalR Spn is phosphorylated by the WalK Spn (VicK) histidine kinase. Little is known about the signals sensed by WalK histidine kinases. To gain information about WalK Spn signal transduction, we performed a kinetic characterization of the WalRK Spn autophosphorylation, phosphoryltransferase, and phosphatase reactions. We were unable to purify soluble full-length WalK Spn . Consequently, these analyses were performed using two truncated versions of WalK Spn lacking its single transmembrane domain. The longer version (Δ35 amino acids) contained most of the HAMP domain and the PAS, DHp, and CA domains, whereas the shorter version (Δ195 amino acids) contained only the DHp and CA domains. The autophosphorylation kinetic parameters of Δ35 and Δ195 WalK Spn were similar [Km (ATP) ≈ 37 μM; k cat ≈ 0.10 min−1] and typical of those of other histidine kinases. The catalytic efficiency of the two versions of WalK Spn ∼P were also similar in the phosphoryltransfer reaction to full-length WalR Spn . In contrast, absence of the HAMP-PAS domains significantly diminished the phosphatase activity of WalK Spn for WalR Spn ∼P. Deletion and point mutations confirmed that optimal WalK Spn phosphatase activity depended on the PAS domain as well as residues in the DHp domain. In addition, these WalK Spn DHp domain and ΔPAS mutations led to attenuation of virulence in a murine pneumonia model.

scholarly journals Genomewide Transcriptional Analysis of the Cold Shock Response in Bacillus subtilis

2002 ◽  
Vol 184 (22) ◽  
pp. 6395-6402 ◽  
Author(s):  
Carsten L. Beckering ◽  
Leif Steil ◽  
Michael H. W. Weber ◽  
Uwe Völker ◽  
Mohamed A. Marahiel
Keyword(s):  
Bacillus Subtilis ◽  
Cold Shock ◽  
Research Field ◽  
Transcriptional Analysis ◽  
Two Component System ◽  
Two Dimensional Gel Electrophoresis ◽  
Component System ◽  
Cold Shock Response ◽  
Two Component ◽  
Shock Response

ABSTRACT Previous studies with two-dimensional gel electrophoresis techniques revealed that the cold shock response in Bacillus subtilis is characterized by rapid induction and accumulation of two classes of specific proteins, which have been termed cold-induced proteins (CIPs) and cold acclimatization proteins (CAPs), respectively. Only recently, the B. subtilis two-component system encoded by the desKR operon has been demonstrated to be essential for the cold-induced expression of the lipid-modifying desaturase Des, which is required for efficient cold adaptation of the membrane in the absence of isoleucine. At present, one of the most intriguing questions in this research field is whether DesKR plays a global role in cold signal perception and transduction in B. subtilis. In this report, we present the first genomewide transcriptional analysis of a cold-exposed bacterium and demonstrate that the B. subtilis two-component system DesKR exclusively controls the desaturase gene des and is not the cold-triggered regulatory system of global relevance. In addition to this, we identified a set of genes that might participate as novel players in the cold shock adaptation of B. subtilis. Two cold-induced genes, the elongation factor homolog ylaG and the σL-dependent transcriptional activator homolog yplP, have been examined by construction and analysis of deletion mutants.

scholarly journals Site-Directed Mutagenesis Identifies a Molecular Switch Involved in Copper Sensing by the Histidine Kinase CinS in Pseudomonas putida KT2440

2009 ◽  
Vol 191 (16) ◽  
pp. 5304-5311 ◽  
Author(s):  
Davide Quaranta ◽  
Megan M. McEvoy ◽  
Christopher Rensing
Keyword(s):  
Pseudomonas Putida ◽  
Histidine Kinase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Copper Binding ◽  
Wild Type ◽  
Two Component System ◽  
Pseudomonas Putida Kt2440 ◽  
Component System ◽  
Two Component

ABSTRACT In the presence of copper, Pseudomonas putida activates transcription of cinAQ via the two-component system CinS-CinR. The CinS-CinR TCS was responsive to 0.5 μM copper and was specifically activated only by copper and silver. Modeling studies of CinS identified a potential copper binding site containing H37 and H147. CinS mutants with H37R and H147R mutations had an almost 10-fold reduced copper-dependent induction of cinAQ compared to the wild type.

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 The PedS2/PedR2 two-component system is crucial for the rare earth element switch in Pseudomonas putida KT2440

2018 ◽  
Author(s):  
Matthias Wehrmann ◽  
Charlotte Berthelot ◽  
Patrick Billard ◽  
Janosch Klebensberger
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Pseudomonas Putida ◽  
Response Regulator ◽  
Regulatory Function ◽  
Methylotrophic Bacteria ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Type Response

ABSTRACTIn Pseudomonas putida KT2440, two pyrroloquinoline quinone-dependent ethanol dehydrogenases (PQQ-EDHs) are responsible for the periplasmic oxidation of a broad variety of volatile organic compounds (VOCs). Depending on the availability of rare earth elements (REEs) of the lanthanide series (Ln3+), we have recently described that the transcription of the genes encoding the Ca2+-utilizing enzyme PedE and the Ln3+-utilizing enzyme PedH are inversely regulated. With adaptive evolution experiments, site-specific mutations, transcriptional reporter fusions, and complementation approaches, we herein demonstrate that the PedS2/PedR2 (PP_2671/PP_2672) two-component system (TCS) plays a central role in the observed REE-mediated switch of PQQ-EDHs in P. putida. We provide evidence that in the absence of lanthanum (La3+), the sensor histidine kinase PedS2 phosphorylates its cognate LuxR-type response regulator PedR2, which in turn not only activates pedE gene transcription but is also involved in repression of pedH. Our data further suggests that the presence of La3+ lowers kinase activity of PedS2, either by the direct binding of the metal ions to the periplasmic region of PedS2 or by an uncharacterized indirect interaction, leading to reduced levels of phosphorylated PedR2. Consequently, the fading pedE expression and concomitant alleviation of pedH repression causes – in conjunction with the transcriptional activation of the pedH gene by a yet unknown regulatory module – the Ln3+-dependent transition from PedE to PedH catalysed oxidation of alcoholic VOCs.IMPORTANCEThe function of lanthanides for methano- and methylotrophic bacteria is gaining increasing attention, while knowledge about the role of rare earth elements (REEs) in non-methylotrophic bacteria is still limited. The present study investigates the recently described differential expression of the two PQQ-EDHs of P. putida in response to lanthanides. We demonstrate that a specific TCS is crucial for their inverse regulation and provide evidence for a dual regulatory function of the LuxR-type response regulator involved. Thus, our study represents the first detailed characterization of the molecular mechanism underlying the REE switch of PQQ-EDHs in a non-methylotrophic bacterium and stimulates subsequent investigations for the identification of additional genes or phenotypic traits that might be co-regulated during REE-dependent niche adaptation.

Expression of styAB is regulated by a two-component system during indigo biosynthesis in Pseudomonas putida

2019 ◽  
Vol 519 (1) ◽  
pp. 198-203
Author(s):  
Lei Cheng ◽  
Jianming Yue ◽  
Sheng Yin ◽  
Mingjing Ren ◽  
Chengtao Wang
Keyword(s):  
Pseudomonas Putida ◽  
Two Component System ◽  
Component System ◽  
Two Component

scholarly journals Transcriptional Studies and Regulatory Interactions between the phoR-phoP Operon and the phoU, mtpA, and ppk Genes of Streptomyces lividans TK24

2006 ◽  
Vol 188 (2) ◽  
pp. 677-686 ◽  
Author(s):  
Sofiane Ghorbel ◽  
Jan Kormanec ◽  
Alexandra Artus ◽  
Marie-Joelle Virolle
Keyword(s):  
Metal Binding ◽  
Parental Strain ◽  
Antibiotic Production ◽  
Streptomyces Lividans ◽  
The Other ◽  
Transcriptional Analysis ◽  
Two Component System ◽  
Component System ◽  
Regulatory Interactions ◽  
Two Component

ABSTRACT The PhoR/PhoP two-component system of Streptomyces lividans was previously shown to allow the growth of the bacteria at low Pi concentrations and to negatively control antibiotic production. The present study focuses on the transcriptional analysis of phoR and phoP, along with the phoU and mtpA genes that are transcribed divergently from the phoRP operon in S. lividans. The effect of phoR, phoP, phoU, and ppk mutations on transcription of these genes was examined under phosphate-replete and phosphate-limited conditions. We demonstrated that phoR and phoP were cotranscribed as a leaderless bicistronic transcript cleaved at discrete sites toward the 3′ end of phoR. In addition, phoP could also be transcribed alone from a promoter located at the 3′ end of phoR. The phoU and mtpA genes, predicted to encode metal binding proteins, were shown to be transcribed as monocistronic transcripts. The expression of phoR-phoP, phoP, and phoU was found to be induced under conditions of Pi limitation in S. lividans TK24. This induction, requiring both PhoR and PhoP, was significantly weaker in the phoU mutant but much stronger in the ppk mutant than in the parental strain. The expression of mtpA was also shown to be up-regulated when Pi was limiting but independently of PhoR/PhoP. The induction of mtpA expression was much stronger in the phoU mutant strain than in the other strains. This study revealed interesting regulatory interactions between the different genes and allowed us to propose putative roles for PhoU and MtpA in the adaptation to phosphate scarcity.

Modeling the Interplay of Pseudomonas putida EIIANtr with the Potassium Transporter KdpFABC

2015 ◽  
Vol 25 (2-3) ◽  
pp. 178-194 ◽  
Author(s):  
S. Wolf ◽  
K. Pflüger-Grau ◽  
A. Kremling
Keyword(s):  
Pseudomonas Putida ◽  
Physiological Mechanism ◽  
Cell Number ◽  
Potassium Uptake ◽  
Phosphotransferase System ◽  
Two Component System ◽  
Component System ◽  
Potassium Transporter ◽  
Starting Point ◽  
Two Component

The nitrogen phosphotransferase system (PTS<sup>Ntr</sup>) of <i>Pseudomonas putida</i> is a key regulatory device that participates in controlling many physiological processes in a posttranscriptional fashion. One of the target functions of the PTS<sup>Ntr</sup> is the regulation of potassium transport. This is mediated by the direct interaction of one of its components with the sensor kinase KdpD of the two-component system controlling transcription of the <i>kdpFABC</i> genes. From a detailed experimental analysis of the activity of the <i>kdpF</i> promoter in <i>P. putida</i> wild-type and <i>pts</i> mutant strains with varying potassium concentrations, we had highly time-resolved data at hand, describing the influence of the PTS<sup>Ntr</sup> on the transcription of the KdpFABC potassium transporter. Here, this data was used to construct a mathematical model based on a black box approach. The model was able to describe the data quantitatively with convincing accuracy. The qualitative interpretation of the model allowed the prediction of two general points describing the interplay between the PTS<sup>Ntr</sup> and the KdpFABC potassium transporter: (1) the influence of cell number on the performance of the <i>kdpF</i> promoter is mainly by dilution by growth and (2) potassium uptake is regulated not only by the activity of the KdpD/KdpE two-component system (in turn influenced by PtsN). An additional controller with integrative behavior is predicted by the model structure. This suggests the presence of a novel physiological mechanism during regulation of potassium uptake with the KdpFABC transporter and may serve as a starting point for further investigations.

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