scholarly journals The Positive Regulator, TraJ, of the Escherichia coli F Plasmid Is Unstable in a cpxA* Background

2002 ◽  
Vol 184 (20) ◽  
pp. 5781-5788 ◽  
Author(s):  
Michael J. Gubbins ◽  
Isabella Lau ◽  
William R. Will ◽  
Janet M. Manchak ◽  
Tracy L. Raivio ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Response Regulator ◽  
Cell Envelope ◽  
Conjugative Plasmid ◽  
F Plasmid ◽  
Gain Of Function ◽  
Positive Regulator ◽  
Envelope Stress ◽  
Detection Of Stress

ABSTRACT The Cpx (conjugative plasmid expression) stress response of Escherichia coli is induced in response to extracytoplasmic signals generated in the cell envelope, such as misfolded proteins in the periplasm. Detection of stress is mediated by the membrane-bound histidine kinase, CpxA. Signaling of the response regulator CpxR by activated CpxA results in the expression of several factors required for responding to cell envelope stress. CpxA was originally thought to be required for the expression of the positive regulator of the F plasmid transfer (tra) operon, TraJ. It was later determined that constitutive gain-of-function mutations in cpxA led to activation of the Cpx envelope stress response and decreased TraJ expression. In order to determine the nature of the downregulation of TraJ, the level of expression of TraJ, TraM, and TraY, the F-encoded regulatory proteins of the F tra region, was determined both in a cpxA* background and in a wild-type background in which the Cpx stress response was induced by overexpression of the outer membrane lipoprotein, NlpE. Our results suggest that TraJ downregulation is controlled by a posttranscriptional mechanism that operates in the cytoplasm in response to upregulation of the Cpx stress response by both the cpxA* gain-of-function mutation and the overexpression of NlpE.

scholarly journals The Cpx Envelope Stress Response Is Controlled by Amplification and Feedback Inhibition

1999 ◽  
Vol 181 (17) ◽  
pp. 5263-5272 ◽  
Author(s):  
Tracy L. Raivio ◽  
Daniel L. Popkin ◽  
Thomas J. Silhavy
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Virulence Factors ◽  
Histidine Kinase ◽  
Feedback Inhibition ◽  
Response Regulator ◽  
Regulatory System ◽  
Concomitant Increase ◽  
Envelope Stress ◽  
Two Component

ABSTRACT In Escherichia coli, the Cpx two-component regulatory system activates expression of protein folding and degrading factors in response to misfolded proteins in the bacterial envelope (inner membrane, periplasm, and outer membrane). It is comprised of the histidine kinase CpxA and the response regulator CpxR. This response plays a role in protection from stresses, such as elevated pH, as well as in the biogenesis of virulence factors. Here, we show that the Cpx periplasmic stress response is subject to amplification and repression through positive and negative autofeedback mechanisms. Western blot and operon fusion analyses demonstrated that the cpxRA operon is autoactivated. Conditions that lead to elevated levels of phosphorylated CpxR cause a concomitant increase in transcription ofcpxRA. Conversely, overproduction of CpxP, a small, Cpx-regulated protein of previously unknown function, represses the regulon and can block activation of the pathway. This repression is dependent on an intact CpxA sensing domain. The ability to autoactivate and then subsequently repress allows for a temporary amplification of the Cpx response that may be important in rescuing cells from transitory stresses and cueing the appropriately timed elaboration of virulence factors.

scholarly journals Alternative Sigma Factor RpoE Is Important for Vibrio parahaemolyticus Cell Envelope Stress Response and Intestinal Colonization

2014 ◽  
Vol 82 (9) ◽  
pp. 3667-3677 ◽  
Author(s):  
Brandy Haines-Menges ◽  
W. Brian Whitaker ◽  
E. Fidelma Boyd
Keyword(s):  
Stress Response ◽  
Vibrio Parahaemolyticus ◽  
Response Regulator ◽  
Cell Envelope ◽  
Polymyxin B ◽  
Content Type ◽  
Alternative Sigma Factors ◽  
Envelope Stress

ABSTRACTVibrio parahaemolyticusis a halophile that inhabits brackish waters and a wide range of hosts, including crustaceans, fish, mollusks, and humans. In humans, it is the leading cause of bacterial seafood-borne gastroenteritis. The focus of this work was to determine the role of alternative sigma factors in the stress response ofV. parahaemolyticusRIMD2210633, an O3:K6 pandemic isolate. Bioinformatics identified five putative extracytoplasmic function (ECF) family of alternative sigma factors: VP0055, VP2210, VP2358, VP2578, and VPA1690. ECF factors typically respond to cell wall/cell envelope stress, iron levels, and the oxidation state of the cell. We have demonstrated here that one such sigma factor, VP2578, a homologue of RpoE fromEscherichia coli, is important for survival under a number of cell envelope stress conditions and in gastrointestinal colonization of a streptomycin-treated adult mouse. In this study, we determined that anrpoEdeletion mutant strain BHM2578 compared to the wild type (WT) was significantly more sensitive to polymyxin B, ethanol, and high-temperature stresses. We demonstrated that inin vivocompetition assays between therpoEmutant and the WT marked with the β-galactosidase genelacZ(WBWlacZ), the mutant strain was defective in colonization compared to the WT. In contrast, deletion of therpoSstress response regulator did not affectin vivosurvival. In addition, we examined the role of the outer membrane protein, OmpU, which inV. choleraeis proposed to be the sole activator of RpoE. We found that anompUdeletion mutant was sensitive to bile salt stress but resistant to polymyxin B stress, indicating OmpU is not essential for the cell envelope stress responses or RpoE function. Overall, these data demonstrate that RpoE is a key cell envelope stress response regulator and, similar toE. coli, RpoE may have several factors that stimulate its function.

scholarly journals Characterization of the CpxRA Regulon in Haemophilus ducreyi

2010 ◽  
Vol 78 (11) ◽  
pp. 4779-4791 ◽  
Author(s):  
Maria Labandeira-Rey ◽  
Chad A. Brautigam ◽  
Eric J. Hansen
Keyword(s):  
Stress Response ◽  
Response Regulator ◽  
Cell Envelope ◽  
Bacterial Species ◽  
Regulatory System ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Envelope Stress ◽  
Two Component ◽  
Genes Encoding

ABSTRACT The H aemophilus ducreyi 35000HP genome encodes a homolog of the CpxRA two-component cell envelope stress response system originally characterized in E scherichia coli. CpxR, the cytoplasmic response regulator, was shown previously to be involved in repression of the expression of the lspB-lspA2 operon (M. Labandeira-Rey, J. R. Mock, and E. J. Hansen, Infect. Immun. 77:3402-3411, 2009). In the present study, the H. ducreyi CpxR and CpxA proteins were shown to closely resemble those of other well-studied bacterial species. A cpxA deletion mutant and a CpxR-overexpressing strain were used to explore the extent of the CpxRA regulon. DNA microarray and real-time reverse transcriptase (RT) PCR analyses indicated several potential regulatory targets for the H. ducreyi CpxRA two-component regulatory system. Electrophoretic mobility shift assays (EMSAs) were used to prove that H. ducreyi CpxR interacted with the promoter regions of genes encoding both known and putative virulence factors of H. ducreyi, including the lspB-lspA2 operon, the flp operon, and dsrA. Interestingly, the use of EMSAs also indicated that H. ducreyi CpxR did not bind to the promoter regions of several genes predicted to encode factors involved in the cell envelope stress response. Taken together, these data suggest that the CpxRA system in H. ducreyi, in contrast to that in E. coli, may be involved primarily in controlling expression of genes not involved in the cell envelope stress response.

scholarly journals The σE Cell Envelope Stress Response of Streptomyces coelicolor Is Influenced by a Novel Lipoprotein, CseA

2006 ◽  
Vol 188 (20) ◽  
pp. 7222-7229 ◽  
Author(s):  
Matthew I. Hutchings ◽  
Hee-Jeon Hong ◽  
Emmanuelle Leibovitz ◽  
Iain C. Sutcliffe ◽  
Mark J. Buttner
Keyword(s):  
Stress Response ◽  
Response Regulator ◽  
Cell Envelope ◽  
Streptomyces Coelicolor ◽  
Signal Transduction System ◽  
Two Component System ◽  
Positive Bacterium ◽  
Sensor Histidine Kinase ◽  
Envelope Stress

ABSTRACT We have investigated the role of CseA in the σE cell envelope stress response of the gram-positive bacterium Streptomyces coelicolor. σE is an extracytoplasmic function RNA polymerase sigma factor required for normal cell envelope integrity in S. coelicolor. σE is encoded within a four-gene operon that also encodes CseA, a protein of unknown function, CseB, a response regulator and CseC, a transmembrane sensor histidine kinase (Cse represents control of sigma E). Previous work has shown that transcription of the sigE gene is completely dependent on the CseBC two-component system and that the CseBC-σE signal transduction system is induced by a wide variety of cell-wall-damaging agents. Here we address the role of CseA, a protein with no homologues outside the streptomycetes. We show that CseA is a novel lipoprotein localized to the extracytoplasmic face of the cell membrane and that loss of CseA results in upregulation of the sigE promoter.

scholarly journals The Escherichia coli CpxA-CpxR Envelope Stress Response System Regulates Expression of the Porins OmpF and OmpC

2005 ◽  
Vol 187 (16) ◽  
pp. 5723-5731 ◽  
Author(s):  
Eric Batchelor ◽  
Don Walthers ◽  
Linda J. Kenney ◽  
Mark Goulian
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Response Regulator ◽  
Gene Encoding ◽  
Fluorescent Reporter ◽  
Response System ◽  
Dnase I Footprinting ◽  
Envelope Stress ◽  
Two Component ◽  
Stress Response System

ABSTRACT We performed transposon mutagenesis of a two-color fluorescent reporter strain to identify new regulators of the porin genes ompF and ompC in Escherichia coli. Screening of colonies by fluorescence microscopy revealed numerous mutants that exhibited interesting patterns of porin expression. One mutant harbored an insertion in the gene encoding the histidine kinase CpxA, the sensor for a two-component signaling system that responds to envelope stress. The cpxA mutant exhibited increased transcription of ompC and a very strong decrease in transcription of ompF under conditions in which acetyl phosphate levels were high. Subsequent genetic analysis revealed that this phenotype is dependent on phosphorylation of the response regulator CpxR and that activation of CpxA in wild-type cells results in similar regulation of porin expression. Using DNase I footprinting, we demonstrated that CpxR binds upstream of both the ompF and ompC promoters. It thus appears that two distinct two-component systems, CpxA-CpxR and EnvZ-OmpR, converge at the porin promoters. Within the context of envelope stress, outer membrane beta-barrel proteins have generally been associated with the sigma E pathway. However, at least for the classical porins OmpF and OmpC, our results show that the Cpx envelope stress response system plays a role in regulating their expression.

scholarly journals Dephosphorylated NPr is involved in an envelope stress response of Escherichia coli

Microbiology ◽  
2015 ◽  
Vol 161 (5) ◽  
pp. 1113-1123 ◽  
Author(s):  
Jaeseop Lee ◽  
Young-Ha Park ◽  
Yeon-Ran Kim ◽  
Yeong-Jae Seok ◽  
Chang-Ro Lee
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Envelope Stress

scholarly journals Phyletic distribution and diversification of the Phage Shock Protein stress response system in bacteria and archaea

2021 ◽  
Author(s):  
Philipp F. Popp ◽  
Vadim M. Gumerov ◽  
Ekaterina P. Andrianova ◽  
Lisa Bewersdorf ◽  
Thorsten Mascher ◽  
...  
Keyword(s):  
Stress Response ◽  
Large Scale ◽  
Cell Envelope ◽  
Model Organisms ◽  
Microbial World ◽  
Natural Classification ◽  
Response System ◽  
Core Proteins ◽  
Envelope Stress

AbstractThe bacterial cell envelope is an essential structure that protects the cell from environmental threats, while simultaneously serving as communication interface and diffusion barrier. Therefore, maintaining cell envelope integrity is of vital importance for all microorganisms. Not surprisingly, evolution has shaped conserved protection networks that connect stress perception, transmembrane signal transduction and mediation of cellular responses upon cell envelope stress. The phage shock protein (PSP) stress response is one of such conserved protection networks. Most of the knowledge about the Psp response comes from studies in the Gram-negative model bacterium, Escherichia coli where the Psp system consists of several well-defined protein components. Homologous systems were identified in representatives of Proteobacteria, Actinobacteria, and Firmicutes; however, the Psp system distribution in the microbial world remains largely unknown. By carrying out a large-scale, unbiased comparative genomics analysis, we found components of the Psp system in many bacterial and archaeal phyla and demonstrated that the PSP system deviates dramatically from the proteobacterial prototype. Two of its core proteins, PspA and PspC, have been integrated in various (often phylum-specifically) conserved protein networks during evolution. Based on protein sequence and gene neighborhood analyses of pspA and pspC homologs, we built a natural classification system of PSP networks in bacteria and archaea. We performed a comprehensive in vivo protein interaction screen for the PSP network newly identified in the Gram-positive model organism Bacillus subtilis and found a strong interconnected PSP response system, illustrating the validity of our approach. Our study highlights the diversity of PSP organization and function across many bacterial and archaeal phyla and will serve as foundation for future studies of this envelope stress response beyond model organisms.

scholarly journals The Rcs System in Enterobacteriaceae: Envelope Stress Responses and Virulence Regulation

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiao Meng ◽  
Glenn Young ◽  
Jingyu Chen
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Cell Envelope ◽  
Regulatory System ◽  
Virulence Regulation ◽  
Bacterial Interaction ◽  
Envelope Stress

The bacterial cell envelope is a protective barrier at the frontline of bacterial interaction with the environment, and its integrity is regulated by various stress response systems. The Rcs (regulator of capsule synthesis) system, a non-orthodox two-component regulatory system (TCS) found in many members of the Enterobacteriaceae family, is one of the envelope stress response pathways. The Rcs system can sense envelope damage or defects and regulate the transcriptome to counteract stress, which is particularly important for the survival and virulence of pathogenic bacteria. In this review, we summarize the roles of the Rcs system in envelope stress responses (ESRs) and virulence regulation. We discuss the environmental and intrinsic sources of envelope stress that cause activation of the Rcs system with an emphasis on the role of RcsF in detection of envelope stress and signal transduction. Finally, the different regulation mechanisms governing the Rcs system’s control of virulence in several common pathogens are introduced. This review highlights the important role of the Rcs system in the environmental adaptation of bacteria and provides a theoretical basis for the development of new strategies for control, prevention, and treatment of bacterial infections.

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