scholarly journals Two-Component Response Regulators of Vibrio fischeri: Identification, Mutagenesis, and Characterization

2007 ◽  
Vol 189 (16) ◽  
pp. 5825-5838 ◽  
Author(s):  
Elizabeth A. Hussa ◽  
Therese M. O'Shea ◽  
Cynthia L. Darnell ◽  
Edward G. Ruby ◽  
Karen L. Visick
Keyword(s):  
Signal Transduction ◽  
Large Scale ◽  
Vibrio Fischeri ◽  
Response Regulators ◽  
Host Interactions ◽  
Vector Integration ◽  
Genomic Approach ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Sense And Respond

ABSTRACT Two-component signal transduction systems are utilized by prokaryotic and eukaryotic cells to sense and respond to environmental stimuli, both to maintain homeostasis and to rapidly adapt to changing conditions. Studies have begun to emerge that utilize a large-scale mutagenesis approach to analyzing these systems in prokaryotic organisms. Due to the recent availability of its genome sequence, such a global approach is now possible for the marine bioluminescent bacterium Vibrio fischeri, which exists either in a free-living state or as a mutualistic symbiont within a host organism such as the Hawaiian squid species Euprymna scolopes. In this work, we identified 40 putative two-component response regulators encoded within the V. fischeri genome. Based on the type of effector domain present, we classified six as NarL type, 13 as OmpR type, and six as NtrC type; the remaining 15 lacked a predicted DNA-binding domain. We subsequently mutated 35 of these genes via a vector integration approach and analyzed the resulting mutants for roles in bioluminescence, motility, and competitive colonization of squid. Through these assays, we identified three novel regulators of V. fischeri luminescence and seven regulators that altered motility. Furthermore, we found 11 regulators with a previously undescribed effect on competitive colonization of the host squid. Interestingly, five of the newly characterized regulators each affected two or more of the phenotypes examined, strongly suggesting interconnectivity among systems. This work represents the first large-scale mutagenesis of a class of genes in V. fischeri using a genomic approach and emphasizes the importance of two-component signal transduction in bacterium-host interactions.

scholarly journals A Selective Tether Recruits Activated Response Regulator CheB to Its Chemoreceptor Substrate

mBio ◽  
2021 ◽  
Author(s):  
Mingshan Li ◽  
Xianjin Xu ◽  
Xiaoqin Zou ◽  
Gerald L. Hazelbauer
Keyword(s):  
Signal Transduction ◽  
Response Regulator ◽  
Response Regulators ◽  
Two Component ◽  
Primary Means ◽  
Two Component Signal Transduction ◽  
Sense And Respond ◽  
Signal Transduction Systems

Two-component signal transduction systems are a primary means by which bacteria sense and respond to their environment. Response regulators are key components of these systems.

Histidine kinases in signal transduction pathways of eukaryotes

1997 ◽  
Vol 110 (10) ◽  
pp. 1141-1145 ◽  
Author(s):  
W.F. Loomis ◽  
G. Shaulsky ◽  
N. Wang
Keyword(s):  
Signal Transduction ◽  
Response Regulator ◽  
Signal Transduction Pathways ◽  
Response Regulators ◽  
Histidine Kinases ◽  
Camp Phosphodiesterase ◽  
Wide Range ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Dependent Protein

Autophosphorylating histidine kinases are an ancient conserved family of enzymes that are found in eubacteria, archaebacteria and eukaryotes. They are activated by a wide range of extracellular signals and transfer phosphate moieties to aspartates found in response regulators. Recent studies have shown that such two-component signal transduction pathways mediate osmoregulation in Saccharomyces cerevisiae, Dictyostelium discoideum and Neurospora crassa. Moreover, they play pivotal roles in responses of Arabidopsis thaliana to ethylene and cytokinin. A transmembrane histidine kinase encoded by dhkA accumulates when Dictyostelium cells aggregate during development. Activation of DhkA results in the inhibition of its response regulator, RegA, which is a cAMP phosphodiesterase that regulates the cAMP dependent protein kinase PKA. When PKA is activated late in the differentiation of prespore cells, they encapsulate into spores. There is evidence that this two-component system participates in a feedback loop linked to PKA in prestalk cells such that the signal to initiate encapsulation is rapidly amplified. Such signal transduction pathways can be expected to be found in a variety of eukaryotic differentiations since they are rapidly reversible and can integrate disparate signals.

scholarly journals RscS Functions Upstream of SypG To Control the syp Locus and Biofilm Formation in Vibrio fischeri

2008 ◽  
Vol 190 (13) ◽  
pp. 4576-4583 ◽  
Author(s):  
Elizabeth A. Hussa ◽  
Cynthia L. Darnell ◽  
Karen L. Visick
Keyword(s):  
Biofilm Formation ◽  
Large Scale ◽  
Vibrio Fischeri ◽  
Response Regulator ◽  
Bacterial Cells ◽  
Euprymna Scolopes ◽  
Regulatory Pathways ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Symbiosis Polysaccharide

ABSTRACTTwo-component signal transduction systems, composed of sensor kinase (SK) and response regulator (RR) proteins, allow bacterial cells to adapt to changes such as environmental flux or the presence of a host. RscS is an SK required forVibrio fischerito initiate a symbiotic partnership with the Hawaiian squidEuprymna scolopes, likely due to its role in controlling the symbiosis polysaccharide (syp) genes and thus biofilm formation. To determine which RR(s) functions downstream of RscS, we performed epistasis experiments with a library of 35 RR mutants. We found that several RRs contributed to RscS-mediated biofilm formation inV. fischeri. However, only thesyp-encoded symbiosis regulator SypG was required for both biofilm phenotypes andsyptranscription induced by RscS. These data support the hypothesis that RscS functions upstream of SypG to induce biofilm formation. In addition, this work also revealed a role for thesyp-encoded RR SypE in biofilm formation. To our knowledge, no other study has used a large-scale epistasis approach to elucidate two-component signaling pathways. Therefore, this work both contributes to our understanding of regulatory pathways important for symbiotic colonization byV. fischeriand establishes a paradigm for evaluating two-component pathways in the genomics era.

scholarly journals Systematic Inactivation and Phenotypic Characterization of Two-Component Signal Transduction Systems of Enterococcus faecalis V583

2004 ◽  
Vol 186 (23) ◽  
pp. 7951-7958 ◽  
Author(s):  
Lynn E. Hancock ◽  
Marta Perego
Keyword(s):  
Signal Transduction ◽  
Antibiotic Resistance ◽  
Environmental Stress ◽  
Enterococcus Faecalis ◽  
Response Regulator ◽  
Phenotypic Characterization ◽  
Response Regulators ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Biofilm Development

ABSTRACT The ability of enterococci to adapt and respond to different environmental stimuli, including the host environment, led us to investigate the role of two-component signal transduction in the regulation of Enterococcus faecalis physiology. Using a bioinformatic approach, we previously identified 17 two-component systems (TCS), consisting of a sensory histidine kinase and the cognate response regulator, as well as an additional orphan response regulator (L. E. Hancock and M. Perego, J. Bacteriol. 184:5819-5825, 2002). In an effort to identify the potential function of each TCS in the biology of E. faecalis clinical isolate strain V583, we constructed insertion mutations in each of the response regulators. We were able to inactivate 17 of 18 response regulators, the exception being an ortholog of YycF, previously shown to be essential for viability in a variety of gram-positive microorganisms. The biological effects of the remaining mutations were assessed by using a number of assays, including antibiotic resistance, biofilm formation, and environmental stress. We identified TCS related to antibiotic resistance and environmental stress and found one system which controls the initiation of biofilm development by E. faecalis.

scholarly journals Cpx Two-Component Signal Transduction inEscherichia coli: Excessive CpxR-P Levels Underlie CpxA* Phenotypes

2000 ◽  
Vol 182 (5) ◽  
pp. 1423-1426 ◽  
Author(s):  
Peter De Wulf ◽  
E. C. C. Lin
Keyword(s):  
Signal Transduction ◽  
Response Regulator ◽  
Response Regulators ◽  
Signal Transduction System ◽  
Regulate Gene Expression ◽  
Adverse Conditions ◽  
Two Component ◽  
Sensor Protein ◽  
Two Component Signal Transduction ◽  
Cognate Response Regulator

ABSTRACT In Escherichia coli, the CpxA-CpxR two-component signal transduction system and the ςE and ς32response pathways jointly regulate gene expression in adaptation to adverse conditions. These include envelope protein distress, heat shock, oxidative stress, high pH, and entry into stationary phase. Certain mutant versions of the CpxA sensor protein (CpxA* proteins) exhibit an elevated ratio of kinase to phosphatase activity on CpxR, the cognate response regulator. As a result, CpxA* strains display numerous phenotypes, many of which cannot be easily related to currently known functions of the CpxA-CpxR pathway. It is unclear whether CpxA* phenotypes are caused solely by hyperphosphorylation of CpxR. We here report that all of the tested CpxA* phenotypes depend on elevated levels of CpxR-P and not on cross-signalling of CpxA* to noncognate response regulators.

scholarly journals Phyletic Distribution and Lineage-Specific Domain Architectures of Archaeal Two-Component Signal Transduction Systems

2017 ◽  
Vol 200 (7) ◽  
Author(s):  
Michael Y. Galperin ◽  
Kira S. Makarova ◽  
Yuri I. Wolf ◽  
Eugene V. Koonin
Keyword(s):  
Signal Transduction ◽  
Protein Interactions ◽  
Environmental Changes ◽  
Metagenomic Data ◽  
Protein Protein Interactions ◽  
Response Regulators ◽  
Histidine Kinases ◽  
Content Type ◽  
Two Component ◽  
Two Component Signal Transduction

ABSTRACTThe two-component signal transduction (TCS) machinery is a key mechanism of sensing environmental changes in the prokaryotic world. TCS systems have been characterized thoroughly in bacteria but to a much lesser extent in archaea. Here, we provide an updated census of more than 2,000 histidine kinases and response regulators encoded in 218 complete archaeal genomes, as well as unfinished genomes available from metagenomic data. We describe the domain architectures of the archaeal TCS components, including several novel output domains, and discuss the evolution of the archaeal TCS machinery. The distribution of TCS systems in archaea is strongly biased, with high levels of abundance in haloarchaea and thaumarchaea but none detected in the sequenced genomes from the phylaCrenarchaeota,Nanoarchaeota, andKorarchaeota. The archaeal sensor histidine kinases are generally similar to their well-studied bacterial counterparts but are often located in the cytoplasm and carry multiple PAS and/or GAF domains. In contrast, archaeal response regulators differ dramatically from the bacterial ones. Most archaeal genomes do not encode any of the major classes of bacterial response regulators, such as the DNA-binding transcriptional regulators of the OmpR/PhoB, NarL/FixJ, NtrC, AgrA/LytR, and ActR/PrrA families and the response regulators with GGDEF and/or EAL output domains. Instead, archaea encode multiple copies of response regulators containing either the stand-alone receiver (REC) domain or combinations of REC with PAS and/or GAF domains. Therefore, the prevailing mechanism of archaeal TCS signaling appears to be via a variety of protein-protein interactions, rather than direct transcriptional regulation.IMPORTANCEAlthough theArchaearepresent a separate domain of life, their signaling systems have been assumed to be closely similar to the bacterial ones. A study of the domain architectures of the archaeal two-component signal transduction (TCS) machinery revealed an overall similarity of archaeal and bacterial sensory modules but substantial differences in the signal output modules. The prevailing mechanism of archaeal TCS signaling appears to involve various protein-protein interactions rather than direct transcription regulation. The complete list of histidine kinases and response regulators encoded in the analyzed archaeal genomes is available online athttp://www.ncbi.nlm.nih.gov/Complete_Genomes/TCSarchaea.html.

scholarly journals Influence of Two-Component Signal Transduction Systems ofLactobacillus caseiBL23 on Tolerance to Stress Conditions

2010 ◽  
Vol 77 (4) ◽  
pp. 1516-1519 ◽  
Author(s):  
Cristina Alcántara ◽  
Ainhoa Revilla-Guarinos ◽  
Manuel Zúñiga
Keyword(s):  
Signal Transduction ◽  
Lactobacillus Casei ◽  
Stress Conditions ◽  
Response Regulators ◽  
Gene Encoding ◽  
Growth Defects ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Signal Transduction Systems

ABSTRACTLactobacillus caseiBL23 carries 17 two-component signal transduction systems. Insertional mutations were introduced into each gene encoding the cognate response regulators, and their effects on growth under different conditions were assayed. Inactivation of systems TC01, TC06, and TC12 (LCABL_02080-LCABL_02090, LCABL_12050-LCABL_12060, and LCABL_19600-LCABL_19610, respectively) led to major growth defects under the conditions assayed.

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