scholarly journals Comparative analysis of two-component signal transduction systems of Bacillus cereus, Bacillus thuringiensis and Bacillus anthracis

Microbiology ◽  
2006 ◽  
Vol 152 (10) ◽  
pp. 3035-3048 ◽  
Author(s):  
Mark de Been ◽  
Christof Francke ◽  
Roy Moezelaar ◽  
Tjakko Abee ◽  
Roland J. Siezen
Keyword(s):  
Signal Transduction ◽  
Bacillus Cereus ◽  
Response Regulator ◽  
Adaptive Responses ◽  
Wide Range ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Host Microbe Interactions ◽  
Cognate Response Regulator ◽  
Signal Transduction Systems

Members of the Bacillus cereus group are ubiquitously present in the environment and can adapt to a wide range of environmental fluctuations. In bacteria, these adaptive responses are generally mediated by two-component signal transduction systems (TCSs), which consist of a histidine kinase (HK) and its cognate response regulator (RR). With the use of in silico techniques, a complete set of HKs and RRs was recovered from eight completely sequenced B. cereus group genomes. By applying a bidirectional best-hits method combined with gene neighbourhood analysis, a footprint of these proteins was made. Around 40 HK-RR gene pairs were detected in each member of the B. cereus group. In addition, each member contained many HK and RR genes not encoded in pairs (‘orphans’). Classification of HKs and RRs based on their enzymic domains together with the analysis of two neighbour-joining trees of these domains revealed putative interaction partners for most of the ‘orphans’. Putative biological functions, including involvement in virulence and host–microbe interactions, were predicted for the B. cereus group HKs and RRs by comparing them with those of B. subtilis and other micro-organisms. Remarkably, B. anthracis appeared to lack specific HKs and RRs and was found to contain many truncated, putatively non-functional, HK and RR genes. It is hypothesized that specialization of B. anthracis as a pathogen could have reduced the range of environmental stimuli to which it is exposed. This may have rendered some of its TCSs obsolete, ultimately resulting in the deletion of some HK and RR genes.

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 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 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.

scholarly journals Comprehensive Studies of Drug Resistance Mediated by Overexpression of Response Regulators of Two-Component Signal Transduction Systems in Escherichia coli

2003 ◽  
Vol 185 (6) ◽  
pp. 1851-1856 ◽  
Author(s):  
Hidetada Hirakawa ◽  
Kunihiko Nishino ◽  
Takahiro Hirata ◽  
Akihito Yamaguchi
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
Drug Resistance ◽  
Response Regulator ◽  
Gene Knockout ◽  
Open Reading Frames ◽  
Two Component ◽  
Two Component Signal Transduction ◽  
Regulator Genes ◽  
Signal Transduction Systems

ABSTRACT In Escherichia coli, there are 32 open reading frames (ORFs) that are assumed to be response regulator genes of two-component signal transduction systems on the basis of sequence similarities. We cloned all of these 32 ORFs into a multicopy expression vector and investigated whether or not they confer drug resistance via control of drug resistance determinants. Fifteen of these ORFs, i.e., baeR, citB, cpxR, evgA, fimZ, kdpE, narL, narP, ompR, rcsB, rstA, torR, yedW, yehT, and dcuR, conferred increased single- or multidrug resistance. Two-thirds of them conferred deoxycholate resistance. Five of them, i.e., evgA, baeR, ompR, cpxR, and rcsB, modulated the expression of several drug exporter genes. The drug resistance mediated by evgA, baeR, and cpxR could be assigned to drug exporters by using drug exporter gene knockout strains.

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