Activation of the AtoSC two-component system in the absence of the AtoC N-terminal receiver domain in E. coli

Amino Acids ◽  
2010 ◽  
Vol 40 (2) ◽  
pp. 421-430 ◽  
Author(s):  
Evaggelos C. Theodorou ◽  
Marina C. Theodorou ◽  
Margarita N. Samali ◽  
Dimitrios A. Kyriakidis
Keyword(s):  
Two Component System ◽  
Component System ◽  
E Coli ◽  
Receiver Domain ◽  
Two Component

Extracellular Ca2+ transients affect poly-(R)-3-hydroxybutyrate regulation by the AtoS-AtoC system in Escherichia coli

2009 ◽  
Vol 417 (3) ◽  
pp. 667-672 ◽  
Author(s):  
Marina C. Theodorou ◽  
Ekaterini Tiligada ◽  
Dimitrios A. Kyriakidis
Keyword(s):  
Escherichia Coli ◽  
Channel Blocker ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Signal Transduction System ◽  
Two Component System ◽  
Component System ◽  
E Coli ◽  
Two Component ◽  
Membrane Bound

Escherichia coli is exposed to wide extracellular concentrations of Ca2+, whereas the cytosolic levels of the ion are subject to stringent control and are implicated in many physiological functions. The present study shows that extracellular Ca2+ controls cPHB [complexed poly-(R)-3-hydroxybutyrate] biosynthesis through the AtoS-AtoC two-component system. Maximal cPHB accumulation was observed at higher [Ca2+]e (extracellular Ca2+ concentration) in AtoS-AtoC-expressing E. coli compared with their ΔatoSC counterparts, in both cytosolic and membrane fractions. The reversal of EGTA-mediated down-regulation of cPHB biosynthesis by the addition of Ca2+ and Mg2+ was under the control of the AtoS-AtoC system. Moreover, the Ca2+-channel blocker verapamil reduced total and membrane-bound cPHB levels, the inhibitory effect being circumvented by Ca2+ addition only in atoSC+ bacteria. Histamine and compound 48/80 affected cPHB accumulation in a [Ca2+]e-dependent manner directed by the AtoS-AtoC system. In conclusion, these data provide evidence for the involvement of external Ca2+ on cPHB synthesis regulated by the AtoS-AtoC two-component system, thus linking Ca2+ with a signal transduction system, most probably through a transporter.

scholarly journals Cross Regulation in Signaling Networks: A FRET Study of the PhoB-PhoR Two-Component System in E-Coli

2012 ◽  
Vol 102 (3) ◽  
pp. 669a
Author(s):  
Hochan Lee ◽  
Shunyuan Zhang ◽  
Yi-Ju Hsieh ◽  
Kirill A. Datsenko ◽  
Barry L. Wanner ◽  
...  
Keyword(s):  
Signaling Networks ◽  
Two Component System ◽  
Component System ◽  
E Coli ◽  
Two Component

scholarly journals YbfA Regulates the Sensitivity of Escherichia coli K12 to Plantaricin BM-1 via the BasS/BasR Two-Component Regulatory System

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinyue Chen ◽  
Yifei Liu ◽  
Junhua Jin ◽  
Hui Liu ◽  
Yanling Hao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Metabolic Pathways ◽  
Gram Negative Bacteria ◽  
Two Component System ◽  
Proteomics Analysis ◽  
Component System ◽  
E Coli ◽  
Two Component ◽  
And Function

Plantaricin BM-1, a class IIa bacteriocin produced by Lactobacillus plantarum BM-1, shows obvious antibacterial activity against Escherichia coli. However, the mechanism underlying the action of class IIa bacteriocins against gram-negative bacteria remains to be explored. The purpose of this study was to investigate the role of YbfA, a DUF2517 domain-containing protein, in the response of Escherichia coli K12 to plantaricin BM-1. The growth curve experiment and MIC experiment showed that the sensitivity of E. coli to plantaricin BM-1 was decreased by a ybfA null mutation. Electron microscopy showed that the ybfA null mutation reduced the surface rupture and contraction caused by plantaricin BM-1, and mitigated the effect of plantaricin BM-1 on the morphology of the E. coli cell membrane. Proteomics analysis showed that 323 proteins were differentially expressed in E. coli lacking the ybfA gene (P < 0.05); 118 proteins were downregulated, and 205 proteins were upregulated. The metabolic pathways containing the upregulated proteins mainly included outer membrane proteins, integral components of the plasma membrane, regulation of cell motility, and regulation of locomotion. The metabolic pathways involving the downregulated proteins mainly included outer membrane protein glycine betaine transport, amino-acid betaine transport, and transmembrane signaling receptor activity. The results of the proteomics analysis showed that the protein expression of the BasS/BasR two-component system was significantly increased (P < 0.05). Moreover, the expression levels of downstream proteins regulated by this two-component system were also significantly increased, including DgkA, FliC, and MlaE, which are involved in cell membrane structure and function, and RT-qPCR also confirmed this result. The growth curve showed that the sensitivity of E. coli to plantaricin BM-1 was significantly increased due to deletion of the BasS/BasR two-component system. Thus, deletion of ybfA in E. coli can increase the expression of the BasS/BasR two-component system and positively regulate the structure and function of the cell membrane to reduce the sensitivity to plantaricin BM-1. This will help to explore the mechanism of action of class IIa bacteriocins against gram-negative bacteria.

scholarly journals BarA-UvrY Two-Component System Regulates Virulence of Uropathogenic E. coli CFT073

PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e31348 ◽  
Author(s):  
Senthilkumar Palaniyandi ◽  
Arindam Mitra ◽  
Christopher D. Herren ◽  
C. Virginia Lockatell ◽  
David E. Johnson ◽  
...  
Keyword(s):  
Two Component System ◽  
Component System ◽  
E Coli ◽  
Two Component

scholarly journals Crystal Structures of the Receiver Domain of the Response Regulator PhoP from Escherichia coli in the Absence and Presence of the Phosphoryl Analog Beryllofluoride

2007 ◽  
Vol 189 (16) ◽  
pp. 5987-5995 ◽  
Author(s):  
Priti Bachhawat ◽  
Ann M. Stock
Keyword(s):  
Escherichia Coli ◽  
Crystal Structures ◽  
Response Regulator ◽  
Active State ◽  
Two Component System ◽  
Component System ◽  
Regulatory Domains ◽  
Receiver Domain ◽  
Two Component ◽  
High Concentrations

ABSTRACT The response regulator PhoP is part of the PhoQ/PhoP two-component system involved in responses to depletion of extracellular Mg2+. Here, we report the crystal structures of the receiver domain of Escherichia coli PhoP determined in the absence and presence of the phosphoryl analog beryllofluoride. In the presence of beryllofluoride, the active receiver domain forms a twofold symmetric dimer similar to that seen in structures of other regulatory domains from the OmpR/PhoB family, providing further evidence that members of this family utilize a common mode of dimerization in the active state. In the absence of activating agents, the PhoP receiver domain crystallizes with a similar structure, consistent with the previous observation that high concentrations can promote an active state of PhoP independent of phosphorylation.

scholarly journals Phosphotransfer Reactions of the CbbRRS Three-Protein Two- Component System from Rhodopseudomonas palustris CGA010 Appear To Be Controlled by an Internal Molecular Switch on the Sensor Kinase

2006 ◽  
Vol 189 (2) ◽  
pp. 325-335 ◽  
Author(s):  
Simona Romagnoli ◽  
F. Robert Tabita
Keyword(s):  
Response Regulator ◽  
Rhodopseudomonas Palustris ◽  
Molecular Switch ◽  
Sensor Kinase ◽  
Two Component System ◽  
Conserved Residues ◽  
Component System ◽  
Receiver Domain ◽  
Two Component

ABSTRACT The CbbRRS system is an atypical three-protein two-component system that modulates the expression of the cbb I CO2 fixation operon of Rhodopseudomonas palustris, possibly in response to a redox signal. It consists of a membrane-bound hybrid sensor kinase, CbbSR, with a transmitter and receiver domain, and two response regulator proteins, CbbRR1 and CbbRR2. No detectable helix-turn-helix DNA binding domain is associated with either response regulator, but an HPt domain and a second receiver domain are predicted at the C-terminal region of CbbRR1 and CbbRR2, respectively. The abundance of conserved residues predicted to participate in a His-Asp phosphorelay raised the question of their de facto involvement. In this study, the role of the multiple receiver domains was elucidated in vitro by generating site-directed mutants of the putative conserved residues. Distinct phosphorylation patterns were obtained with two truncated versions of the hybrid sensor kinase, CbbSRT189 and CbbSRR96 (CbbSR beginning at residues T189 and R96, respectively). These constructs also exhibited substantially different affinities for ATP and phosphorylation stability, which was found to be dependent on a conserved Asp residue (Asp-696) within the kinase receiver domain. Asp-696 also played an important role in defining the specificity of phosphorylation for response regulators CbbRR1 or CbbRR2, and this residue appeared to act in conjunction with residues within the region from Arg-96 to Thr-189 at the N terminus of the sensor kinase. The net effect of concerted interactions at these distinct regions of CbbSR created an internal molecular switch that appears to coordinate a unique branched phosphorelay system.

scholarly journals The Lipoprotein NlpE Is a Cpx Sensor That Serves as a Sentinel for Protein Sorting and Folding Defects in theEscherichia coliEnvelope

2019 ◽  
Vol 201 (10) ◽  
Author(s):  
Antoine Delhaye ◽  
Géraldine Laloux ◽  
Jean-François Collet
Keyword(s):  
Outer Membrane ◽  
Two Component System ◽  
Oxidative Folding ◽  
Component System ◽  
Content Type ◽  
E Coli ◽  
Outer Membrane Lipoprotein ◽  
Physiological Relevance ◽  
Two Component ◽  
Membrane Lipoprotein

ABSTRACTThe envelope of Gram-negative bacteria is a complex compartment that is essential for viability. To ensure survival of the bacterial cells in fluctuating environments, several signal transduction systems, called envelope stress response systems (ESRSs), exist to monitor envelope biogenesis and homeostasis. The Cpx two-component system is an extensively studied ESRS inEscherichia colithat is active during exposure to a vast array of stresses and protects the envelope under those harmful circumstances. Overproduction of NlpE, a two-domain outer membrane lipoprotein of unclear function, has been used in numerous studies as a molecular trigger to turn on the system artificially. However, the mechanism of Cpx activation by NlpE, as well as its physiological relevance, awaited further investigation. In this paper, we provide novel insights into the role played by NlpE in the Cpx system. We found that, among all outer membrane lipoproteins inE. coli, NlpE is sufficient to induce Cpx when lipoprotein trafficking is perturbed. Under such conditions, fitness is increased by the presence of NlpE. Moreover, we show that NlpE, through its N-terminal domain, physically interacts with the Cpx sensor kinase CpxA. Our data suggest that NlpE also serves to activate the Cpx system during oxidative folding defects in the periplasm and that its C-terminal domain is involved in the sensing mechanism. Overall, our data demonstrate that NlpE acts as a sentinel for two important envelope biogenesis processes, namely, lipoprotein sorting and oxidative folding, and they further establish NlpE as a bona fide member of the Cpx two-component system.IMPORTANCEBacteria rely on a sophisticated envelope to shield them against challenging environmental conditions and therefore need to ensure correct envelope assembly and integrity. A major signaling pathway that performs this role in Gram-negative species is the Cpx system. An outer membrane lipoprotein of unclear function, NlpE, has long been exploited as a research tool to study Cpx inE. coli, since it triggers this system when overproduced or mislocalized; however, the mechanism and physiological relevance of the NlpE-Cpx connection have awaited further investigation. We elucidate a new function for NlpE by showing that it physically interacts with the Cpx sensor CpxA and acts as a sentinel that specifically monitors two essential envelope biogenesis processes, namely, lipoprotein sorting and oxidative folding.

scholarly journals The Escherichia coli BarA-UvrY Two-Component System Is Needed for Efficient Switching between Glycolytic and Gluconeogenic Carbon Sources

2003 ◽  
Vol 185 (3) ◽  
pp. 843-853 ◽  
Author(s):  
Anna-Karin Pernestig ◽  
Dimitris Georgellis ◽  
Tony Romeo ◽  
Kazushi Suzuki ◽  
Henrik Tomenius ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Response Regulator ◽  
Carbon Sources ◽  
Regulation System ◽  
Wild Type ◽  
Two Component System ◽  
Kinase Gene ◽  
Component System ◽  
E Coli ◽  
Two Component

ABSTRACT The Escherichia coli BarA and UvrY proteins were recently demonstrated to constitute a novel two-component system, although its function has remained largely elusive. Here we show that mutations in the sensor kinase gene, barA, or the response regulator gene, uvrY, in uropathogenic E. coli drastically affect survival in long-term competition cultures. Using media with gluconeogenic carbon sources, the mutants have a clear growth advantage when competing with the wild type, but using media with carbon sources feeding into the glycolysis leads to a clear growth advantage for the wild type. Results from competitions with mutants in the carbon storage regulation system, CsrA/B, known to be a master switch between glycolysis and gluconeogenesis, led us to propose that the BarA-UvrY two-component system controls the Csr system. Taking these results together, we propose the BarA-UvrY two-component system is crucial for efficient adaptation between different metabolic pathways, an essential function for adaptation to a new environment.

scholarly journals A Biosensor for Detection of Indole Metabolites

2021 ◽  
Author(s):  
Jiefei Wang ◽  
Chao Zhang ◽  
W. Seth Childers
Keyword(s):  
Ulcerative Colitis ◽  
High Specificity ◽  
Two Component System ◽  
Protein Database ◽  
Component System ◽  
E Coli ◽  
Aryl Hydrocarbon ◽  
Two Component ◽  
Single Plasmid ◽  
Health Related

ABSTRACTThe lack of diverse health-related biosensors limits the progress towards our understanding of how the microbiome metabolism impacts health. Microbially produced indole-3-aldehyde (I3A) has been associated with reducing inflammation in diseases such as ulcerative colitis by stimulating the aryl hydrocarbon receptor (AhR) pathway. We mined the protein database for gut microbiome metabolites’ sensors and developed a biosensor for I3A. We engineered E. coli embedded with a single plasmid carrying a chimeric two-component system that detects I3A. Our I3A receptor characterization identified residues that contribute to the sensor’s high specificity in a range of 0.1-10 µM. The I3A biosensor opens the door to sensing indole metabolites produced at the host-microbe interface and provides new parts for synthetic biology applications.

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