scholarly journals Three Parallel Quorum-Sensing Systems Regulate Gene Expression in Vibrio harveyi

2004 ◽  
Vol 186 (20) ◽  
pp. 6902-6914 ◽  
Author(s):  
Jennifer M. Henke ◽  
Bonnie L. Bassler
Keyword(s):  
Quorum Sensing ◽  
Communication Systems ◽  
Vibrio Harveyi ◽  
Signal Molecules ◽  
Phenotypic Analysis ◽  
Regulate Gene Expression ◽  
Sensing Systems ◽  
Extracellular Signal ◽  
System 2 ◽  
System 1

ABSTRACT In a process called quorum sensing, bacteria communicate using extracellular signal molecules termed autoinducers. Two parallel quorum-sensing systems have been identified in the marine bacterium Vibrio harveyi. System 1 consists of the LuxM-dependent autoinducer HAI-1 and the HAI-1 sensor, LuxN. System 2 consists of the LuxS-dependent autoinducer AI-2 and the AI-2 detector, LuxPQ. The related bacterium, Vibrio cholerae, a human pathogen, possesses System 2 (LuxS, AI-2, and LuxPQ) but does not have obvious homologues of V. harveyi System 1. Rather, System 1 of V. cholerae is made up of the CqsA-dependent autoinducer CAI-1 and a sensor called CqsS. Using a V. cholerae CAI-1 reporter strain we show that many other marine bacteria, including V. harveyi, produce CAI-1 activity. Genetic analysis of V. harveyi reveals cqsA and cqsS, and phenotypic analysis of V. harveyi cqsA and cqsS mutants shows that these functions comprise a third V. harveyi quorum-sensing system that acts in parallel to Systems 1 and 2. Together these communication systems act as a three-way coincidence detector in the regulation of a variety of genes, including those responsible for bioluminescence, type III secretion, and metalloprotease production.

scholarly journals Peptide signaling without feedback in signal production operates as a true quorum sensing communication system in Bacillus subtilis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Dogsa ◽  
Mihael Spacapan ◽  
Anna Dragoš ◽  
Tjaša Danevčič ◽  
Žiga Pandur ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Quorum Sensing ◽  
Cell Density ◽  
Communication System ◽  
Communication Systems ◽  
Feedback Loop ◽  
Signal Molecules ◽  
Specific Cell ◽  
Sharp Transition

AbstractBacterial quorum sensing (QS) is based on signal molecules (SM), which increase in concentration with cell density. At critical SM concentration, a variety of adaptive genes sharply change their expression from basic level to maximum level. In general, this sharp transition, a hallmark of true QS, requires an SM dependent positive feedback loop, where SM enhances its own production. Some communication systems, like the peptide SM-based ComQXPA communication system of Bacillus subtilis, do not have this feedback loop and we do not understand how and if the sharp transition in gene expression is achieved. Based on experiments and mathematical modeling, we observed that the SM peptide ComX encodes the information about cell density, specific cell growth rate, and even oxygen concentration, which ensure power-law increase in SM production. This enables together with the cooperative response to SM (ComX) a sharp transition in gene expression level and this without the SM dependent feedback loop. Due to its ultra-sensitive nature, the ComQXPA can operate at SM concentrations that are 100–1000 times lower than typically found in other QS systems, thereby substantially reducing the total metabolic cost of otherwise expensive ComX peptide.

scholarly journals Quorum Sensing of Acidophiles: A Communication System in Microorganisms

2021 ◽  
Author(s):  
Xueyan Gao ◽  
Jianqiang Lin ◽  
Linxu Chen ◽  
Jianqun Lin ◽  
Xin Pang
Keyword(s):  
Quorum Sensing ◽  
Population Density ◽  
Intercellular Communication ◽  
Communication System ◽  
Communication Systems ◽  
Biological Function ◽  
Regulatory Mechanism ◽  
Signal Molecules ◽  
Acidic Environment ◽  
Cell Cooperation

Communication is important for organisms living in nature. Quorum sensing system (QS) are intercellular communication systems that promote the sociality of microbes. Microorganisms could promote cell-to-cell cooperation and population density to adapt to the changing environment through QS-mediated regulation that is dependent on the secretion and the detection of signal molecules (or called autoinducers). QS system is also discovered in acidophiles, a microorganism that is widely used in the bioleaching industry and can live in an acidic environment. An example is the LuxI/R-like QS system (AfeI/R) that has been reported in the chemoautotrophic species of the genus Acidithiobacillus. In this chapter, we will introduce the types and distribution of the QS system, and the biological function and regulatory mechanism of QS in acidophiles. We will also discuss the potential ecological function of QS system and the application value of the QS system in the control and regulation of the bioleaching process in the related industries and acid mine damage.

scholarly journals Saccharomyces cerevisiae Requires CFF1 To Produce 4-Hydroxy-5-Methylfuran-3(2H)-One, a Mimic of the Bacterial Quorum-Sensing Autoinducer AI-2

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Julie S. Valastyan ◽  
Christina M. Kraml ◽  
Istvan Pelczer ◽  
Thomas Ferrante ◽  
Bonnie L. Bassler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quorum Sensing ◽  
Bacterial Species ◽  
Cell Communication ◽  
Communication Process ◽  
Signal Molecules ◽  
Catalytic Residue ◽  
Interspecies Communication ◽  
Content Type ◽  
Extracellular Signal

ABSTRACT Quorum sensing is a process of cell-to-cell communication that bacteria use to orchestrate collective behaviors. Quorum sensing depends on the production, release, and detection of extracellular signal molecules called autoinducers (AIs) that accumulate with increasing cell density. While most AIs are species specific, the AI called AI-2 is produced and detected by diverse bacterial species, and it mediates interspecies communication. We recently reported that mammalian cells produce an AI-2 mimic that can be detected by bacteria through the AI-2 receptor LuxP, potentially expanding the role of the AI-2 system to interdomain communication. Here, we describe a second molecule capable of interdomain signaling through LuxP, 4-hydroxy-5-methylfuran-3(2H)-one (MHF), that is produced by the yeast Saccharomyces cerevisiae. Screening the S. cerevisiae deletion collection revealed Cff1p, a protein with no known role, to be required for MHF production. Cff1p is proposed to be an enzyme, with structural similarity to sugar isomerases and epimerases, and substitution at the putative catalytic residue eliminated MHF production in S. cerevisiae. Sequence analysis uncovered Cff1p homologs in many species, primarily bacterial and fungal, but also viral, archaeal, and higher eukaryotic. Cff1p homologs from organisms from all domains can complement a cff1Δ S. cerevisiae mutant and restore MHF production. In all cases tested, the identified catalytic residue is conserved and required for MHF to be produced. These findings increase the scope of possibilities for interdomain interactions via AI-2 and AI-2 mimics, highlighting the breadth of molecules and organisms that could participate in quorum sensing. IMPORTANCE Quorum sensing is a cell-to-cell communication process that bacteria use to monitor local population density. Quorum sensing relies on extracellular signal molecules called autoinducers (AIs). One AI called AI-2 is broadly made by bacteria and used for interspecies communication. Here, we describe a eukaryotic AI-2 mimic, 4-hydroxy-5-methylfuran-3(2H)-one, (MHF), that is made by the yeast Saccharomyces cerevisiae, and we identify the Cff1p protein as essential for MHF production. Hundreds of viral, archaeal, bacterial, and eukaryotic organisms possess Cff1p homologs. This finding, combined with our results showing that homologs from all domains can replace S. cerevisiae Cff1p, suggests that like AI-2, MHF is widely produced. Our results expand the breadth of organisms that may participate in quorum-sensing-mediated interactions.

scholarly journals Peptide-based quorum sensing systems in Paenibacillus polymyxa

2019 ◽  
Author(s):  
Maya Voichek ◽  
Sandra Maaß ◽  
Tobias Kroniger ◽  
Dörte Becher ◽  
Rotem Sorek
Keyword(s):  
Quorum Sensing ◽  
Communication Systems ◽  
Transcriptional Response ◽  
Paenibacillus Polymyxa ◽  
Host Interactions ◽  
Sensing Systems ◽  
Single Genome ◽  
Intracellular Receptor ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPaenibacillus polymyxa is an agriculturally important plant growth-promoting rhizobacterium. Many Paenibacillus species are known to be engaged in complex bacteria-bacteria and bacteria-host interactions, which in other species were shown to necessitate quorum sensing communication. However, to date no quorum sensing systems have been described in Paenibacillus. Here we show that the type strain P. polymyxa ATCC 842 encodes at least 16 peptide-based communication systems. Each of these systems is comprised of a pro-peptide that is secreted to the growth medium and processed to generate a mature short peptide. Each peptide has a cognate intracellular receptor of the RRNPP family, and we show that external addition of P. polymyxa communication peptides leads to reprogramming of the transcriptional response. We found that these quorum sensing systems are conserved across hundreds of species belonging to the Paenibacillaceae family, with some species encoding more than 25 different peptide-receptor pairs, representing a record number of quorum sensing systems encoded in a single genome.

scholarly journals Quorum-sensing blockade as a strategy for enhancing host defences against bacterial pathogens

2007 ◽  
Vol 362 (1483) ◽  
pp. 1213-1222 ◽  
Author(s):  
Thomas Bjarnsholt ◽  
Michael Givskov
Keyword(s):  
Quorum Sensing ◽  
Drug Target ◽  
Immune Modulation ◽  
Resistant Bacteria ◽  
Signal Molecules ◽  
Antibiotic Resistant ◽  
Bacterial Pathogenicity ◽  
Extracellular Signal ◽  
Conventional Antibiotics ◽  
Antimicrobial Treatments

Conventional antibiotics target the growth and the basal life processes of bacteria leading to growth arrest and cell death. The selective force that is inherently linked to this mode of action eventually selects out antibiotic-resistant variants. The most obvious alternative to antibiotic-mediated killing or growth inhibition would be to attenuate the bacteria with respect to pathogenicity. The realization that Pseudomonas aeruginosa , and a number of other pathogens, controls much of their virulence arsenal by means of extracellular signal molecules in a process denoted quorum sensing (QS) gave rise to a new ‘drug target rush’. Recently, QS has been shown to be involved in the development of tolerance to various antimicrobial treatments and immune modulation. The regulation of virulence via QS confers a strategic advantage over host defences. Consequently, a drug capable of blocking QS is likely to increase the susceptibility of the infecting organism to host defences and its clearance from the host. The use of QS signal blockers to attenuate bacterial pathogenicity, rather than bacterial growth, is therefore highly attractive, particularly with respect to the emergence of multi-antibiotic resistant bacteria.

Signal-mediated cross-talk regulates stress adaptation in Vibrio species

Microbiology ◽  
2003 ◽  
Vol 149 (7) ◽  
pp. 1923-1933 ◽  
Author(s):  
Diane McDougald ◽  
Sujatha Srinivasan ◽  
Scott A. Rice ◽  
Staffan Kjelleberg
Keyword(s):  
Quorum Sensing ◽  
Cross Talk ◽  
Communication System ◽  
Communication Systems ◽  
Vibrio Vulnificus ◽  
Homoserine Lactone ◽  
Sensing System ◽  
Sensing Systems ◽  
Quorum Sensing System ◽  
Signalling Systems

Quorum sensing systems serve as a means of ‘census taking’ of conspecific and non-conspecific bacteria in the near vicinity. The acylated homoserine lactone (AHL) quorum sensing system has been proposed to be primarily an intra-specific communication system, while the AI-2 autoinducer signalling system is proposed to be an interspecific communication system. Here it is shown that AI-2-like signalling in two marine Vibrio species, Vibrio vulnificus and ‘Vibrio angustum’ S14, induces the core response phenotypes of starvation adaptation and stress resistance, and that a signal antagonist can competitively inhibit these phenotypes. Furthermore, the signals produced by a range of Vibrio species have the ability to induce these phenotypes in V. vulnificus and ‘V. angustum’ S14, indicating that, at least in Vibrio species, AI-2-like signalling systems function as interspecies communication systems capable of ‘cross-talk’ and of regulating environmentally relevant phenotypes.

scholarly journals ThePseudomonas aeruginosaLasR quorum-sensing receptor balances ligand selectivity and sensitivity

2018 ◽  
Author(s):  
Amelia R. McCready ◽  
Jon E. Paczkowski ◽  
Brad R. Henke ◽  
Bonnie L. Bassler
Keyword(s):  
Quorum Sensing ◽  
Ligand Binding ◽  
Cell Communication ◽  
Communication Process ◽  
Signal Molecules ◽  
Ligand Selectivity ◽  
Existing Structures ◽  
Binding Domains ◽  
Extracellular Signal ◽  
Sensitivity And Selectivity

AbstractQuorum sensing is a cell-cell communication process that bacteria use to orchestrate group behaviors. Quorum sensing is mediated by extracellular signal molecules called autoinducers. Autoinducers are often structurally similar, raising questions concerning how bacteria distinguish among them. Here, we use thePseudomonas aeruginosaLasR quorum-sensing receptor to explore receptor sensitivity and selectivity. Alteration of LasR amino acid S129 increases ligand selectivity and decreases ligand sensitivity. Conversely, the L130F mutation enhances LasR sensitivity while reducing selectivity. We solve crystal structures of LasR ligand binding domains complexed with non-cognate autoinducers. Comparison to existing structures reveals that ligand selectivity/sensitivity is mediated by a flexible loop adjacent to the ligand binding site. We show thatP. aeruginosaharboring LasR variants with modified selectivity or sensitivity exhibit altered quorum-sensing responses. We suggest that an evolutionary trade-off between ligand selectivity and sensitivity enables LasR to optimally regulate quorum-sensing traits.

scholarly journals Saccharomyces cerevisiae Requires CFF1 to Produce 4-hydroxy-5-methylfuran-3(2H)-one, a Mimic of the Bacterial Quorum-Sensing Autoinducer AI-2

2020 ◽  
Author(s):  
Julie S. Valastyan ◽  
Christina M. Kraml ◽  
Istvan Pelczer ◽  
Thomas Ferrante ◽  
Bonnie L. Bassler
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quorum Sensing ◽  
Mammalian Cells ◽  
Bacterial Species ◽  
Local Population ◽  
Cell Communication ◽  
Communication Process ◽  
Signal Molecules ◽  
Catalytic Residue ◽  
Extracellular Signal

AbstractQuorum sensing is a process of cell-to-cell communication that bacteria use to orchestrate collective behaviors. Quorum sensing depends on the production, release, and detection of extracellular signal molecules called autoinducers (AIs) that accumulate with increasing cell density. While most AIs are species-specific, the AI called AI-2 is produced and detected by diverse bacterial species and it mediates inter-species communication. We recently reported that mammalian cells produce an AI-2 mimic that can be detected by bacteria through the AI-2 receptor, LuxP, potentially expanding the role of the AI-2 system to inter-domain communication. Here, we describe a second molecule capable of inter-domain signaling through LuxP, 4-hydroxy-5-methylfuran-3(2H)-one (MHF) that is produced by the yeast Saccharomyces cerevisiae. Screening the S. cerevisiae deletion collection revealed Cff1p, a protein with no known role, to be required for MHF production. Cff1p is proposed to be an enzyme, possibly an epimerase or isomerase, and substitution at the putative catalytic residue eliminated MHF production in S. cerevisiae. Sequence analysis uncovered Cff1p homologs in many species, primarily bacterial and fungal, but also viral, archaeal, and higher eukaryotic. Cff1p homologs from organisms from all domains can complement a S. cerevisiae cff1Δ mutant and restore MHF production. In all test cases, the identified catalytic residue is conserved and required for MHF to be produced. These findings increase the scope of possibilities for inter-domain interactions via AI-2 and AI-2 mimics, highlighting the breadth of molecules and organisms that could participate in quorum sensing.ImportanceQuorum sensing is a cell-to-cell communication process that bacteria use to monitor local population density. Quorum sensing relies on extracellular signal molecules called autoinducers (AIs). One AI, called AI-2, is broadly made by bacteria and used for inter-species communication. Here, we describe a eukaryotic AI-2 mimic, 5-methylfuran-3(2H)-one, (MHF), that is made by the yeast Saccharomyces cerevisiae, and we identify the Cff1p protein as essential for MHF production. Hundreds of viral, archaeal, bacterial, and eukaryotic organisms possess Cff1p homologs. This finding, combined with our results showing that homologs from all domains can replace S. cerevisiae Cff1p, suggests that like AI-2, MHF is widely produced. Our results expand the breadth of organisms that may participate in quorum-sensing-mediated interactions.

scholarly journals Isolation of novel quorum-sensing active bacteria from microbial mats in Shark Bay Australia

2019 ◽  
Vol 95 (4) ◽  
Author(s):  
James C Charlesworth ◽  
Cara Watters ◽  
Hon Lun Wong ◽  
Pieter T Visscher ◽  
Brendan P Burns
Keyword(s):  
Quorum Sensing ◽  
Microbial Mats ◽  
Signal Molecules ◽  
E Coli ◽  
Signalling Molecules ◽  
Shark Bay ◽  
Sensing Systems ◽  
Complex Phenotypes ◽  
Layer Chromatography ◽  
Tlc Separation

ABSTRACT Quorum sensing is a potent system of genetic control allowing phenotypes to be coordinated across localized communities. In this study, quorum sensing systems in Shark Bay microbial mats were delineated using a targeted approach analyzing whole mat extractions as well as the creation of an isolate library. A library of 165 isolates from different mat types were screened using the AHL biosensor E. coli MT102. Based on sequence identity 30 unique isolates belonging to Proteobacteria, Actinobacteria and Firmicutes were found to activate the AHL biosensor, suggesting AHLs or analogous compounds were potentially present. Several of the isolates have not been shown previously to produce signal molecules, particularly the members of the Actinobacteria and Firmicutes phyla including Virgibacillus, Halobacillius, Microbacterium and Brevibacterium. These active isolates were further screened using thin-layer chromatography (TLC) providing putative identities of AHL molecules present within the mat communities. Nine isolates were capable of producing several spots of varying sizes after TLC separation, suggesting the presence of multiple signalling molecules. This study is the first to delineate AHL-based signalling in the microbial mats of Shark Bay, and suggests quorum sensing may play a role in the ecosphysiological coordination of complex phenotypes across microbial mat communities.

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