scholarly journals ArcS, the Cognate Sensor Kinase in an Atypical Arc System of Shewanella oneidensis MR-1

2010 ◽  
Vol 76 (10) ◽  
pp. 3263-3274 ◽  
Author(s):  
Jürgen Lassak ◽  
Anna-Lena Henche ◽  
Lucas Binnenkade ◽  
Kai M. Thormann
Keyword(s):  
Escherichia Coli ◽  
Response Regulator ◽  
Phylogenetic Analyses ◽  
Shewanella Oneidensis ◽  
Sensor Kinase ◽  
Two Component System ◽  
Oxygen Levels ◽  
Protein Protein Interaction ◽  
Sequence Homologies ◽  
Cognate Response Regulator

ABSTRACT The availability of oxygen is a major environmental factor for many microbes, in particular for bacteria such as Shewanella species, which thrive in redox-stratified environments. One of the best-studied systems involved in mediating the response to changes in environmental oxygen levels is the Arc two-component system of Escherichia coli, consisting of the sensor kinase ArcB and the cognate response regulator ArcA. An ArcA ortholog was previously identified in Shewanella, and as in Escherichia coli, Shewanella ArcA is involved in regulating the response to shifts in oxygen levels. Here, we identified the hybrid sensor kinase SO_0577, now designated ArcS, as the previously elusive cognate sensor kinase of the Arc system in Shewanella oneidensis MR-1. Phenotypic mutant characterization, transcriptomic analysis, protein-protein interaction, and phosphotransfer studies revealed that the Shewanella Arc system consists of the sensor kinase ArcS, the single phosphotransfer domain protein HptA, and the response regulator ArcA. Phylogenetic analyses suggest that HptA might be a relict of ArcB. Conversely, ArcS is substantially different with respect to overall sequence homologies and domain organizations. Thus, we speculate that ArcS might have adopted the role of ArcB after a loss of the original sensor kinase, perhaps as a consequence of regulatory adaptation to a redox-stratified environment.

scholarly journals Biochemical Activities of the absA Two-Component System of Streptomyces coelicolor

2005 ◽  
Vol 187 (2) ◽  
pp. 687-696 ◽  
Author(s):  
Nancy L. Sheeler ◽  
Susan V. MacMillan ◽  
Justin R. Nodwell
Keyword(s):  
Transcriptional Repression ◽  
Kinase Activity ◽  
Response Regulator ◽  
Streptomyces Coelicolor ◽  
Point Mutations ◽  
Stable State ◽  
Sensor Kinase ◽  
Two Component System ◽  
Antibiotic Synthesis ◽  
Cognate Response Regulator

ABSTRACT The AbsA1 sensor kinase and its cognate response regulator AbsA2 are important regulators of antibiotic synthesis in Streptomyces coelicolor. While certain point mutations in absA1 reduce or eliminate the synthesis of several antibiotics, null mutations in these genes bring about enhanced antibiotic synthesis. We show here that AbsA1, which is unusual in sequence and structure, is both an AbsA2 kinase and an AbsA2∼P phosphatase. The half-life of AbsA2∼P in solution is 68.6 min, consistent with a role in maintaining a relatively stable state of transcriptional repression or activation. We find that mutations in the absA locus that enhance antibiotic synthesis impair AbsA2 kinase activity and that mutations that repress antibiotic synthesis impair AbsA2∼P phosphatase activity. These results support a model in which the phosphorylation state of AbsA2 is determined by the balance of the kinase and phosphatase activities of AbsA1 and where AbsA2∼P represses antibiotic biosynthetic genes either directly or indirectly.

scholarly journals pH-Dependent Activation of the BarA-UvrY Two-Component System in Escherichia coli

2006 ◽  
Vol 188 (23) ◽  
pp. 8303-8306 ◽  
Author(s):  
Verónica Mondragón ◽  
Bernardo Franco ◽  
Kristina Jonas ◽  
Kazushi Suzuki ◽  
Tony Romeo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Response Regulator ◽  
Central Carbon Metabolism ◽  
Sensor Kinase ◽  
Two Component System ◽  
Physiological Signal ◽  
Two Component ◽  
Central Carbon ◽  
External Ph

ABSTRACT The barA and uvrY genes of Escherichia coli encode a two-component sensor kinase and a response regulator, respectively. Although this system plays a major role in the regulation of central carbon metabolism, motility, and biofilm formation by controlling the expression of the CsrB and CsrC noncoding RNAs, the environmental conditions and the physiological signal(s) to which it responds remain obscure. In this study, we explored the effect of external pH on the activity of BarA/UvrY. Our results indicate that a pH lower than 5.5 provides an environment that does not allow activation of the BarA/UvrY signaling pathway.

scholarly journals The KdpD Sensor Kinase of Escherichia coli Responds to Several Distinct Signals To Turn on Expression of the Kdp Transport System

2015 ◽  
Vol 198 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Wolfgang Epstein
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Transport System ◽  
Kinase Activity ◽  
Response Regulator ◽  
Sensor Kinase ◽  
Monovalent Cations ◽  
Two Component System ◽  
Content Type ◽  
E Coli

ABSTRACTKdp, one of three saturable K+uptake systems inEscherichia coli, is the system with the highest affinity for K+and the only one whose expression is strongly controlled by medium K+concentration. Expression is controlled by a two-component system of KdpD, the sensor kinase, and KdpE, the response regulator. There is general agreement that expression occurs when the growth rate of cells begins to become limited by K+availability. How K+limitation results in expression has been controversial. Studying the roles of the major components of the growth medium shows that KdpD senses at least two distinct signals inside the cell, those of Na+and NH4+, and it probably senses other monovalent cations in the cell. KdpD does not sense turgor.IMPORTANCEThe expression of the Kdp K+transport system ofE. colioccurs when cells become limited in their growth rate by the availability of K+. Cells sense limited K+and try to compensate by taking up other monovalent cations, particularly Na+and NH4+. These cations are sensed in the cytoplasm by the KdpD response regulator, presumably to stimulate its kinase activity. It is shown that KdpD does not sense turgor, as was suggested earlier.

scholarly journals The Two-Component Regulatory System TCS08 Is Involved in Cellobiose Metabolism of Streptococcus pneumoniae R6

2006 ◽  
Vol 189 (4) ◽  
pp. 1342-1350 ◽  
Author(s):  
Stuart J. McKessar ◽  
Regine Hakenbeck
Keyword(s):  
Streptococcus Pneumoniae ◽  
Response Regulator ◽  
Regulatory System ◽  
Phosphotransferase System ◽  
Two Component System ◽  
Transcription Profiles ◽  
Regulatory Systems ◽  
Two Component ◽  
Cognate Response Regulator ◽  
Gram Positive Cocci

ABSTRACT The two-component system TCS08 is one of the regulatory systems that is important for virulence of Streptococcus pneumoniae. In order to investigate the TCS08 regulon, we have analyzed transcription profiles of mutants derived from S. pneumoniae R6 by microarray analysis. Since deletion mutants are often without a significant phenotype, we constructed a mutation in the histidine kinase HK08, T133P, in analogy to the phosphatase mutation T230P in the H box of the S. pneumoniae CiaH kinase described recently (D. Zähner, K. Kaminski, M. van der Linden, T. Mascher, M. Merai, and R. Hakenbeck, J. Mol. Microbiol. Biotechnol. 4:211-216, 2002). In addition, a deletion mutation was constructed in rr08, encoding the cognate response regulator. The most heavily suppressed genes in the hk08 mutant were spr0276 to spr0282, encoding a putative cellobiose phosphoenolpyruvate sugar phosphotransferase system (PTS). Whereas the R6 Smr parent strain and the Δrr08 mutant readily grew on cellobiose, the hk08 mutant and selected mutants with deletions in the PTS cluster did not, strongly suggesting that TCS08 is involved in the catabolism of cellobiose. Homologues of the TCS08 system were found in closely related streptococci and other gram-positive cocci. However, the genes spr0276 to spr0282, encoding the putative cellobiose PTS, represent a genomic island in S. pneumoniae and homologues were found in Streptococcus gordonii only, suggesting that this system might contribute to the pathogenicity potential of the pneumococcus.

scholarly journals The ArcB Sensor Kinase of Escherichia coli Autophosphorylates by an Intramolecular Reaction

2010 ◽  
Vol 192 (6) ◽  
pp. 1735-1739 ◽  
Author(s):  
Gabriela R. Peña-Sandoval ◽  
Dimitris Georgellis
Keyword(s):  
Response Regulator ◽  
Bond Formation ◽  
Sensor Kinase ◽  
Two Component System ◽  
Histidine Kinases ◽  
Intramolecular Reaction ◽  
Redox Active ◽  
Intermolecular Disulfide Bond ◽  
Two Component ◽  
Respiratory Conditions

ABSTRACT The Arc two-component system, comprising the ArcB sensor kinase and the ArcA response regulator, modulates the expression of numerous genes in response to the respiratory conditions of growth. ArcB is a tripartite histidine kinase whose activity is regulated by the oxidation of two cytosol-located redox-active cysteine residues that participate in intermolecular disulfide bond formation. Here we show that ArcB autophosphorylates through an intramolecular reaction which diverges from the usually envisaged intermolecular autophosphorylation of homodimeric histidine kinases.

scholarly journals Investigation of the Role of Electrostatic Charge in Activation of the Escherichia coli Response Regulator CheY

2003 ◽  
Vol 185 (21) ◽  
pp. 6385-6391 ◽  
Author(s):  
Jenny G. Smith ◽  
Jamie A. Latiolais ◽  
Gerald P. Guanga ◽  
Sindhura Citineni ◽  
Ruth E. Silversmith ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Amino Acid ◽  
Active Site ◽  
Response Regulator ◽  
Residual Activity ◽  
Phosphoryl Group ◽  
Sensor Kinase ◽  
Amino Acid Substitutions ◽  
Flagellar Rotation

ABSTRACT In a two-component regulatory system, an important means of signal transduction in microorganisms, a sensor kinase phosphorylates a response regulator protein on an aspartyl residue, resulting in activation. The active site of the response regulator is highly charged (containing a lysine, the phosphorylatable aspartate, two additional aspartates involved in metal binding, and an Mg2+ ion), and introduction of the dianionic phosphoryl group results in the repositioning of charged moieties. Furthermore, substitution of one of the Mg2+-coordinating aspartates with lysine or arginine in the Escherichia coli chemotaxis response regulator CheY results in phosphorylation-independent activation. In order to examine the consequences of altered charge distribution for response regulator activity and to identify possible additional amino acid substitutions that result in phosphorylation-independent activation, we made 61 CheY mutants in which residues close to the site of phosphorylation (Asp57) were replaced by various charged amino acids. Most substitutions (47 of 61) resulted in the complete loss of CheY activity, as measured by the inability to support clockwise flagellar rotation. However, 10 substitutions, all introducing a new positive charge, resulted in the loss of chemotaxis but in the retention of some clockwise flagellar rotation. Of the mutants in this set, only the previously identified CheY13DK and CheY13DR mutants displayed clockwise activity in the absence of the CheA sensor kinase. The absence of negatively charged substitution mutants with residual activity suggests that the introduction of additional negative charges into the active site is particularly deleterious for CheY function. Finally, the spatial distribution of positions at which amino acid substitutions are functionally tolerated or not tolerated is consistent with the presently accepted mechanism of response regulator activation and further suggests a possible role for Met17 in signal transduction by CheY.

scholarly journals Polar Localization of a Tripartite Complex of the Two-Component System DcuS/DcuR and the Transporter DctA in Escherichia coli Depends on the Sensor Kinase DcuS

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e115534 ◽  
Author(s):  
Patrick D. Scheu ◽  
Philipp A. Steinmetz ◽  
Felix Dempwolff ◽  
Peter L. Graumann ◽  
Gottfried Unden
Keyword(s):  
Escherichia Coli ◽  
Sensor Kinase ◽  
Two Component System ◽  
Component System ◽  
Polar Localization ◽  
Two Component

scholarly journals Reduction of Turgor Is Not the Stimulus for the Sensor Kinase KdpD of Escherichia coli

2008 ◽  
Vol 190 (7) ◽  
pp. 2360-2367 ◽  
Author(s):  
Knut Hamann ◽  
Petra Zimmann ◽  
Karlheinz Altendorf
Keyword(s):  
Escherichia Coli ◽  
Cytoplasmic Membrane ◽  
Current View ◽  
Sensor Kinase ◽  
Two Component System ◽  
Intracellular Atp ◽  
Two Component ◽  
Stimulus Perception ◽  
First Time

ABSTRACT Stimulus perception by the KdpD/KdpE two-component system of Escherichia coli is still controversial with respect to the nature of the stimulus that is perceived by the sensor kinase KdpD. Limiting potassium concentrations in the medium or high osmolality leads to KdpD/KdpE signal transduction, resulting in kdpFABC expression. It has been hypothesized that changes in turgor are sensed by KdpD through alterations in the physical state of the cytoplasmic membrane. However, in this study the quantitative determination of expression levels of the kdpFABC operon revealed that the system responds very effectively to K+-limiting conditions in the medium but barely and to various degrees to salt and sugar stress. Since the current view of stimulus perception calls for mainly intracellular parameters, which might be sensed by KdpD, we set out to test the cytoplasmic concentrations of ATP, K+, Na+, glutamate, proline, glycine, trehalose, putrescine, and spermidine under K+-limiting conditions. As a first result, the determination of the cytoplasmic volume, which is a prerequisite for such measurements, revealed that a transient shrinkage of the cytoplasmic volume, which is indicative of a reduction in turgor, occurred only under osmotic upshift but not under K+-limiting conditions. Furthermore, the intracellular ATP concentration significantly increased under osmotic upshift, whereas only a slight increase occurred after a potassium downshift. Finally, the cytoplasmic K+ concentration rose severalfold only after an osmotic upshock. For the first time, these data indicate that stimulus perception by KdpD correlates neither with changes in the cytoplasmic volume nor with changes in the intracellular ATP or K+ concentration or those of the other solutes tested. In conclusion, we propose that a reduction in turgor cannot be the stimulus for KdpD.

scholarly journals A Novel Three-Protein Two-Component System Provides a Regulatory Twist on an Established Circuit To Modulate Expression of the cbbI Region of Rhodopseudomonas palustris CGA010

2006 ◽  
Vol 188 (8) ◽  
pp. 2780-2791 ◽  
Author(s):  
Simona Romagnoli ◽  
F. Robert Tabita
Keyword(s):  
Response Regulator ◽  
Rhodopseudomonas Palustris ◽  
Sensor Kinase ◽  
Response Regulators ◽  
Transcription Activator ◽  
Two Component System ◽  
Bisphosphate Carboxylase ◽  
Control Of Gene Expression ◽  
Component System ◽  
Two Component

ABSTRACT A novel two-component system has been identified in the cbbI region of the nonsulfur purple photosynthetic bacterium Rhodopseudomonas palustris. Genes encoding this system, here designated cbbRRS, are juxtaposed between the divergently transcribed transcription activator gene, cbbR, and the form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) genes, cbbLS. The three genes of the cbbRRS system represent a variation of the well-known two-component signal transduction systems, as there are a transmembrane hybrid sensor kinase and two response regulators, with no apparent DNA binding domain associated with any of the three proteins encoded by these genes. In this study, we showed that the membrane-bound full-length kinase undergoes autophosphorylation and transfers phosphate to both response regulators. A soluble, truncated version of the kinase was subsequently prepared and found to catalyze phosphorylation of response regulator 1 but not response regulator 2, implying that conformational changes and/or sequence-specific regions of the kinase are important for discriminating between the two response regulators. Analyses indicated that a complex network of control of gene expression must occur, with CbbR required for the expression of the cbbLS genes but dispensable for the synthesis of form II RubisCO (encoded by cbbM). The CbbRRS proteins specifically affected the activity and accumulation of form I RubisCO (CbbLS), as revealed by analyses of nonpolar, unmarked gene deletions. A tentative model of regulation suggested that changes in the phosphotransfer activity of the sensor kinase, possibly in response to a redox metabolic signal, cause modulation of the activity and synthesis of form I RubisCO.

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