scholarly journals PsyR, a transcriptional regulator in quorum sensing system, binds lux box-like sequence in psyI promoter without AHL quorum sensing molecule and activates psyI transcription with AHL in Pseudomonas syringae pv. tabaci 6605

2019 ◽  
Vol 86 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Yuki Ichinose ◽  
Yousuke Tasaka ◽  
Satoru Yamamoto ◽  
Yuko Inoue ◽  
Motohiro Takata ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Pseudomonas Syringae ◽  
Transcriptional Regulator ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Quorum Sensing Molecule

scholarly journals Autoinduction of Vitreoscilla Hemoglobin Enhanced the Production of Syringomycin from Pseudomonas syringae HS191

2021 ◽  
Vol 9 (1) ◽  
pp. 12-18
Keyword(s):  
Quorum Sensing ◽  
Pseudomonas Syringae ◽  
Oxygen Supply ◽  
Expression System ◽  
Vitreoscilla Hemoglobin ◽  
Logarithmic Phase ◽  
Wild Type ◽  
High Concentration ◽  
Sensing System ◽  
Quorum Sensing System

Syringomycin is a cyclic lipodepsipeptide produced by strains of Pseudomonas syringae. The potent herbicidal and fungicidal activities of syringomycin make it a promising compound for fungiostasis and weed control. However, the production of syringomycin from the wild-type strains is low. The discoveries that Pseudomonas syringae is aerobic, and the syringomycin synthetase SyrB2 is an O2-dependent halogenase, led us to establish an autoinducible Vitreoscilla hemoglobin expression system for oxygen supply during fermentation, thereby increasing the yield of syringomycin. By employing the quorum sensing system for the expression of Vitreoscilla hemoglobin gene (vgb), we found that Pseudomonas syringae HS191 that expressed vgb, facilitated the cell growth and the general biomass. Furthermore, syringomycin bioassay showed that the fungal inhibition zones increased from 2.5 mm to 3.2 mm, and HPLC analysis confirmed that the expression of vgb resulted in a 71.1% increase in syringomycin production compared to the wild-type strain. The Vitreoscilla hemoglobin has been widely applied to fermentation optimization; however, in the case of Pseudomonas, increased oxygen supply is only beneficial during the stationary phase, while a high concentration of oxygen inhibited the cell propagation during the logarithmic phase. Here we report the autoinduction of Vitreoscilla hemoglobin by engineering the quorum-sensing system. This synthetic circuit significantly improved the syringomycin production. The Vitreoscilla hemoglobin-autoinduction system not only caters to the dynamic oxygen demand but also avoids inducer supplementation.

scholarly journals Functions Required for Extracellular Quinolone Signaling by Pseudomonas aeruginosa

2002 ◽  
Vol 184 (23) ◽  
pp. 6472-6480 ◽  
Author(s):  
Larry A. Gallagher ◽  
Susan L. McKnight ◽  
Marina S. Kuznetsova ◽  
Everett C. Pesci ◽  
Colin Manoil
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Secondary Metabolites ◽  
Regulatory Network ◽  
Biosynthetic Pathway ◽  
Extracellular Enzymes ◽  
Transcriptional Regulator ◽  
Transposon Mutagenesis ◽  
Sensing System ◽  
Quorum Sensing System

ABSTRACT A set of 30 mutants exhibiting reduced production of the phenazine poison pyocyanin were isolated following transposon mutagenesis of Pseudomonas aeruginosa PAO1. The mutants could be subdivided into those with defects in the primary phenazine biosynthetic pathway and those with more pleiotropic defects. The largest set of pleiotropic mutations blocked the production of the extracellular Pseudomonas quinolone signal (PQS), a molecule required for the synthesis of secondary metabolites and extracellular enzymes. Most of these pqs mutations affected genes which appear to encode PQS biosynthetic functions, although a transcriptional regulator and an apparent response effector were also represented. Two of the genes required for PQS synthesis (phnA and phnB) had previously been assumed to encode phenazine biosynthetic functions. The transcription of one of the genes required for PQS synthesis (PA2587/pqsH) was regulated by the LasI/R quorum-sensing system, thereby linking quorum sensing and PQS regulation. Others of the pleiotropic phenazine-minus mutations appear to inactivate novel components of the quorum-sensing regulatory network, including one regulator (np20) previously shown to be required for virulence in neutropenic mice.

scholarly journals Loci identification of a N-acyl homoserine lactone type quorum sensing system and a new LysR-type transcriptional regulator associated with antimicrobial activity and swarming in Burkholderia gladioli UAPS07070

2019 ◽  
Vol 14 (1) ◽  
pp. 165-178
Author(s):  
E. Seynos-García ◽  
M. Castañeda-Lucio ◽  
J. Muñoz-Rojas ◽  
L. López-Pliego ◽  
M. Villalobos ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Quorum Sensing ◽  
Transcriptional Regulator ◽  
Homoserine Lactone ◽  
Sensing System ◽  
Gene Coding ◽  
Burkholderia Gladioli ◽  
Quorum Sensing System ◽  
First Time ◽  
Random Transposition

AbstractA random transposition mutant library of B. gladioli UAPS07070 was analyzed for searching mutants with impaired microbial antagonism. Three derivates showed diminished antimicrobial activity against a sensitive strain. The mutated loci showed high similarity to the quorum sensing genes of the AHL-synthase and its regulator. Another mutant was affected in a gene coding for a LysrR-type transcriptional regulator. The production of toxoflavin, the most well known antimicrobial-molecule and a major virulence factor of plant-pathogenic B. glumae and B. gladioli was explored. The absence of a yellowish pigment related to toxoflavin and the undetectable transcription of toxA in the mutants indicated the participation of the QS system and of the LysR-type transcriptional regulator in the regulation of toxoflavin. Additionally, those genes were found to be related to the swarming phenotype. Lettuce inoculated with the AHL synthase and the lysR mutants showed less severe symptoms. We present evidence of the participation of both, the quorum sensing and for the first time, of a LysR-type transcriptional regulator in antibiosis and swarming phenotype in a strain of B. gladioli

scholarly journals Quorum-Sensing Regulation of a Copper Toxicity System in Pseudomonas aeruginosa

2010 ◽  
Vol 192 (10) ◽  
pp. 2557-2568 ◽  
Author(s):  
Joshua T. Thaden ◽  
Stephen Lory ◽  
Timothy S. Gardner
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Molecular Genetic ◽  
Copper Toxicity ◽  
Transcriptional Regulator ◽  
Global Gene Expression ◽  
Copper Resistance ◽  
Binding Motif ◽  
Sensing System ◽  
Quorum Sensing System

ABSTRACT The LasR/LasI quorum-sensing system in Pseudomonas aeruginosa influences global gene expression and mediates pathogenesis. In this study, we show that the quorum-sensing system activates, via the transcriptional regulator PA4778, a copper resistance system composed of 11 genes. The quorum-sensing global regulator LasR was recently shown to directly activate transcription of PA4778, a cueR homolog and a MerR-type transcriptional regulator. Using molecular genetic methods and bioinformatics, we verify the interaction of LasR with the PA4778 promoter and further demonstrate the LasR binding site. We also identify a putative PA4778 binding motif and show that the protein directly binds to and activates five promoters controlling the expression of 11 genes—PA3519 to -15, PA3520, mexPQ-opmE, PA3574.1, and cueA, a virulence factor in a murine model. Using gene disruptions, we show that PA4778, along with 7 of 11 gene targets of PA4778, increases the sensitivity of P. aeruginosa to elevated copper concentrations. This work identifies a cellular function for PA4778 and four other previously unannotated genes (PA3515, PA3516, PA3517, and PA3518) and suggests a potential role for copper in the quorum response. We propose to name PA4778 cueR.

scholarly journals Identification of flavone and its derivatives as potential inhibitors of transcriptional regulator LasR of Pseudomonas aeruginosa using virtual screening

2019 ◽  
Author(s):  
Narek Abelyan ◽  
Hovakim Grabski ◽  
Susanna Tiratsuyan
Keyword(s):  
Amino Acids ◽  
Virtual Screening ◽  
Quorum Sensing ◽  
Ligand Binding ◽  
Transcriptional Regulator ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Potential Inhibitors

AbstractAntibiotic resistance is a global problem nowadays and in 2017 the World Health Organization published the list of bacteria for which treatment are urgently needed, where Pseudomonas aeruginosa is of critical priority. Current therapies lack efficacy because this organism creates biofilms conferring increased resistance to antibiotics and host immune responses. The strategy is to “not kill, but disarm” the pathogen and resistance will be developed slowly. It has been shown that LasI/LasR system is the main component of the quorum sensing system in P. aeruginosa. LasR is activated by the interaction with its native autoinducer. A lot flavones and their derivatives are used as antibacterial drug compounds. The purpose is to search compounds that will inhibit LasR. This leads to the inhibition of the synthesis of virulence factors thus the bacteria will be vulnerable and not virulent. We performed virtual screening using multiple docking programs for obtaining consensus predictions. The results of virtual screening suggest benzamides which are synthetical derivatives of flavones as potential inhibitors of transcriptional regulator LasR. These are consistent with recently published experimental data, which demonstrate the high antibacterial activity of benzamides. The compounds interact with the ligand binding domain of LasR with higher binding affinity than with DNA binding domain. Among the selected compounds, by conformational analysis, it was found that there are compounds that bind to the same amino acids of ligand binding domain as the native autoinducer. This could indicate the possibility of competitive interaction of these compounds. A number of compounds that bind to other conservative amino acids ligand binding domain have also been discovered, which will be of interest for further study. Selected compounds meet the criteria necessary for their consideration as drugs and can serve as a basis for conducting further in vitro / in vivo experiments. It could be used for the development of modern anti-infective therapy based on the quorum sensing system of P. aeruginosa.HighlightsVirtual screening using multiple docking programs for consensus predictions.Virtual screening reveal benzamides as potential inhibitors of LasR.Selected compounds bind to the same amino acids of LBD as the native autoinducer.Selected compounds meet the criteria necessary for their consideration as drugs.GRAPHICAL ABSTRACT1: N- (1,3-benzodioxol-5-ylmethyl) -4- (6,8-dimethyl-4-oxochromen-2-yl) benzamide docking with LBD of LasR, A — ligand conformation predicted by AutoDock, B - by rDock and C - by LeDock,D - binding of CID 108754330 with LBD of LasR predicted by rDock.2: Four types of P. aeruginosa quorum sensing signaling systems I. Las, II. Rhl, III. Pqs and IV. IQS.

scholarly journals Expression of the bviIR and cepIR Quorum-Sensing Systems of Burkholderia vietnamiensis

2007 ◽  
Vol 189 (8) ◽  
pp. 3006-3016 ◽  
Author(s):  
Rebecca J. Malott ◽  
Pamela A. Sokol
Keyword(s):  
Quorum Sensing ◽  
Burkholderia Cepacia ◽  
Regulatory Element ◽  
Transcriptional Regulator ◽  
Homoserine Lactone ◽  
Burkholderia Vietnamiensis ◽  
Sensing System ◽  
Sensing Systems ◽  
Quorum Sensing System ◽  
Regulatory Organization

ABSTRACT Burkholderia vietnamiensis has both the cepIR quorum-sensing system that is widely distributed among the Burkholderia cepacia complex (BCC) and the bviIR system. Comparison of the expression of cepI, cepR, bviI, and bviR-luxCDABE fusions in B. vietnamiensis G4 and the G4 cepR and bviR mutants determined that the expression of bviI requires both a functional cognate regulator, BviR, and functional CepR. The cepIR system, however, is not regulated by BviR. Unlike the cepIR genes in other BCC species, the cepIR genes are not autoregulated in G4. N-Acyl-homoserine lactone (AHL) production profiles in G4 cepI, cepR, bviI, and bviR mutants confirmed the regulatory organization of the G4 quorum-sensing systems. The regulatory network in strain PC259 is similar to that in G4, except that CepR positively regulates cepI and negatively regulates cepR. AHL production and the bviI expression levels in seven B. vietnamiensis isolates were compared. All strains produced N-octanoyl-homoserine lactone and N-hexanoyl-homoserine lactone; however, only one of four clinical strains but all three environmental strains produced the BviI synthase product, N-decanoyl-homoserine lactone (DHL). The three strains that did not produce DHL expressed bviR but not bviI. Heterologous expression of bviR restored DHL production in these strains. The bviIR loci of the non-DHL-producing strains were sequenced to confirm that bviR encodes a functional transcriptional regulator. Lack of expression of G4 bviI in these three strains indicated that an additional regulatory element may be involved in the regulation of bviIR expression in certain strains of B. vietnamiensis.

Genetic and functional diversity of PsyI/PsyR quorum-sensing system in the Pseudomonas syringae complex

2020 ◽  
Author(s):  
Tomohiro Morohoshi ◽  
Akinori Oshima ◽  
Xiaonan Xie ◽  
Nobutaka Someya
Keyword(s):  
Escherichia Coli ◽  
Quorum Sensing ◽  
Pseudomonas Syringae ◽  
Dna Sequences ◽  
Homoserine Lactone ◽  
Sensing System ◽  
Sensing Systems ◽  
Quorum Sensing System ◽  
High Level ◽  
Functionally Diverse

Abstract Strains belonging to the Pseudomonas syringae complex often possess quorum-sensing systems that comprise N-acyl-l-homoserine lactone (AHL) synthase (PsyI) and AHL receptors (PsyR). Here, we investigated the diversity of PsyI/PsyR quorum-sensing systems in 630 strains of the P. syringae complex. AHL production was observed in most strains of P. amygdali and P. meliae, and a few strains of P. coronafaciens and P. syringae. The DNA sequences of psyIR and their upstream and downstream regions were categorized into eight types. P. amygdali pv. myricae, P. savastanoi, and P. syringae pv. solidagae, maculicola, broussonetiae, and tomato encoded psyI, but did not produce detectable amounts of AHL. In P. savastanoi, an amino acid substitution (R27S) in PsyI caused defective AHL production. The psyI gene of P. syringae pv. tomato was converted to pseudogenes by frameshift mutations. Escherichia coli harboring psyI genes from P. amygdali pv. myricae, P. syringae pv. solidagae and broussonetiae showed high level of AHL production. Forced expression of functional psyR restored AHL production in P. amygdali pv. myricae and P. syringae pv. solidagae. In conclusion, our study indicates that the PsyI/PsyR quorum-sensing systems in P. syringae strains are genetically and functionally diverse, with diversity being linked to phylogenetic and pathovar classifications.

scholarly journals Specificity and Polymorphism of the PlcR-PapR Quorum-Sensing System in the Bacillus cereus Group

2005 ◽  
Vol 187 (3) ◽  
pp. 1182-1187 ◽  
Author(s):  
Leyla Slamti ◽  
Didier Lereclus
Keyword(s):  
Quorum Sensing ◽  
Bacillus Cereus ◽  
Transcriptional Regulator ◽  
Bacillus Cereus Group ◽  
Sensing System ◽  
Quorum Sensing System ◽  
A Cell ◽  
Processed Form ◽  
Is Strain

ABSTRACT The expression of extracellular virulence factors in various species of the Bacillus cereus group is controlled by the plcR and papR genes, which encode a transcriptional regulator and a cell-cell signaling peptide, respectively. A processed form of PapR, presumably a pentapeptide, specifically interacts with PlcR to facilitate its binding to its DNA targets. This activating mechanism is strain specific, with this specificity being determined by the first residue of the pentapeptide. We carried out in vivo complementation assays and compared the PlcR-PapR sequences of 29 strains from the B. cereus group. Our findings suggested that the fifth amino acid of the pentapeptide is also involved in the specificity of activation. We identified four classes of PlcR-PapR pairs, defining four distinct pherotypes in the B. cereus group. We used these findings to look at the evolution of the PlcR-PapR quorum-sensing system with regard to the phylogeny of the species forming the B. cereus group.

Sign in / Sign up

Export Citation Format

Share Document