Let LuxS speak up in AI-2 signaling

Keersmaecker, Sigrid C. J. De; Sonck, K.; Vanderleyden, Jos

doi:10.1016/j.tim.2006.01.003

Cited by 152 publications

(120 citation statements)

References 49 publications

(121 reference statements)

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“…When the concentration of the autoinducers reaches a threshold, an alteration of gene expression is induced, allowing the bacteria to adopt behaviors that are only productive when the bacteria are working together as a group [3,4]. Among many different mechanisms for QS by bacteria, one is shared by both gram-negative and gram-positive bacteria, involving the production of autoinducer 2 (AI-2) [5][6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

et al. 2009

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In quorum sensing (QS) process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 (AI-2), a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coli and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho-AI-2 renders LsrR unable to bind to its own promoter in vitro.

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Section: Introductionmentioning

confidence: 99%

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

et al. 2009

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“…All LuxS protein sequences exhibit the invariant His-Xaa-Xaa-Glu-His motif (Fig. 5), which is important in the catalytic activity of LuxS [26] and Gly-92 which is important in LuxS function as shown for C. jejuni [27].…”

Section: Luxs Sequence and Genomic Locationmentioning

confidence: 99%

Quorum sensing dependent phenotypes and their molecular mechanisms inCampylobacterales

Gölz¹,

Sharbati²,

Backert³

et al. 2012

European Journal of Microbiology and Immunology

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Quorum sensing comprises the mechanism of communication between numerous bacteria via small signalling molecules, termed autoinducers (AI). Using quorum sensing, bacteria can regulate the expression of multiple genes involved in virulence, toxin production, motility, chemotaxis and biofilm formation, thus contributing to adaptation as well as colonisation. The current understanding of the role of quorum sensing in the lifecycle of Campylobacterales is still incomplete. Campylobacterales belong to the class of Epsilonproteobacteria representing a physiologically and ecologically diverse group of bacteria that are rather distinct from the more commonly studied Proteobacteria, such as Escherichia and Salmonella. This review summarises the recent knowledge on distribution and production of AI molecules, as well as possible quorum sensing dependent regulation in the mostly investigated species within the Campylobacterales group: Campylobacter jejuni and Helicobacter pylori.

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“…There is AI-2 activity in LAPS 7, 8 and probably this is the main reason for which L. plantarum supernatants have biofilm inhibitory capacity.AI-2 has been proposed to serve as a 'universal' signal for interspecies communication 13,14 and chemically generally are furanosyl borate diester 15,16 . For this reason we measured AI-2 activity in LAPS27 to LAPS32 (which were obtained in presence of different sources of boron) by using the V. harveyi BB170 bioassay.…”

Section: 31autoinducer Type 2 (Ai-2) Activity In Laps27 To Laps32mentioning

confidence: 99%

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Lindon¹,

Cruz²,

Cabral³

et al. 2016

IJPSR

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ABSTRACT:Lactobacillus plantarum culture supernatants (LAPS) have antimicrobial, pro-healing and anesthetic properties, so our medical team applied whole cultures and LAPS in chronic wounds with encouraging results. Metabolites responsible for LAPS properties and its action mechanism were previously determined. Objective: to design methods and culture media to increase the production of LAPS metabolites and optimize it´s therapeutic effectiveness. Modifications in MRS broth composition were made and L. plantarum was cultivated in the resulting different media with different physicochemical conditions to obtain modified supernatants (LAPS m ). Antimicrobial and anti-biofilm activity (crystal violet) of LAPS m on strains typically isolated from chronic wounds (Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis and Serratiamarcescens), was tested. Concentration of barbiturates in LAPS m was quantified by GCMS and its relative anesthetic potency in healthy volunteers was evaluated. DNAase and auto inducers type 2biological activity in LAPS m were quantified. In addition, a safety assessment of LAPS m application on healthy skin of 200 volunteers was performed. LAPS m obtained from media with high concentrations of yeast extract possessed the greatest anesthetic power. Those containing greater amount of proteins, cations and surfactants had the highest capacity of biofilm disruption (p<0.01). When glucose and galactose concentration were increased in media, LAPS m had the greatest antimicrobial power (p<0.05). Finally, there is great safety in the application of LAPS m as no edema or erythema was observed. The results obtained will allow the manufacture of LAPS m with greater therapeutic effectiveness and even custom properties for each type of wound.

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Let LuxS speak up in AI-2 signaling

Cited by 152 publications

References 49 publications

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

LsrR-binding site recognition and regulatory characteristics in Escherichia coli AI-2 quorum sensing

Quorum sensing dependent phenotypes and their molecular mechanisms inCampylobacterales

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