scholarly journals Characterization of a Phosphotriesterase-Like Lactonase fromSulfolobus solfataricusand Its Immobilization for Disruption of Quorum Sensing

2010 ◽  
Vol 77 (4) ◽  
pp. 1181-1186 ◽  
Author(s):  
Filomena S. W. Ng ◽  
Daniel M. Wright ◽  
Stephen Y. K. Seah
Keyword(s):  
Quorum Sensing ◽  
Virulence Factors ◽  
Acyl Chain ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Homoserine Lactones ◽  
Specificity Constant ◽  
Chain Lengths ◽  
Quorum Sensing Signals

ABSTRACTSsoPox, a bifunctional enzyme with organophosphate hydrolase andN-acyl homoserine lactonase activities from the hyperthermophilic archaeonSulfolobus solfataricus, was overexpressed and purified from recombinantPseudomonas putidaKT2440 with a yield of 9.4 mg of protein per liter of culture. The enzyme has a preference forN-acyl homoserine lactones (AHLs) with acyl chain lengths of at least 8 carbon atoms, mainly due to lowerKmvalues for these substrates. The highest specificity constant obtained was forN-3-oxo-decanoyl homoserine lactone (kcat/Km= 5.5 × 103M−1·s−1), but SsoPox can also degradeN-butyryl homoserine lactone (C4-HSL) andN-oxo-dodecanoyl homoserine lactone (oxo-C12-HSL), which are important for quorum sensing in ourPseudomonas aeruginosamodel system. WhenP. aeruginosaPAO1 cultures were grown in the presence of SsoPox-immobilized membranes, the production of C4-HSL- and oxo-C12-HSL-regulated virulence factors, elastase, protease, and pyocyanin were significantly reduced. This is the first demonstration that immobilized quorum-quenching enzymes can be used to attenuate the production of virulence factors controlled by quorum-sensing signals.

scholarly journals LuxR Solos in the Plant Endophyte Kosakonia sp. Strain KO348

2020 ◽  
Vol 86 (13) ◽  
Author(s):  
Susan Mosquito ◽  
Xianfa Meng ◽  
Giulia Devescovi ◽  
Iris Bertani ◽  
Alexander M. Geller ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Homoserine Lactone ◽  
The Other ◽  
The Novel ◽  
Homoserine Lactones ◽  
Interkingdom Signaling ◽  
Promoter Studies ◽  
Quorum Sensing Signals ◽  
Target Promoter ◽  
Plant Compounds

ABSTRACT Endophytes are microorganisms that live inside plants and are often beneficial for the host. Kosakonia is a novel bacterial genus that includes several species that are diazotrophic and plant associated. This study revealed two quorum sensing-related LuxR solos, designated LoxR and PsrR, in the plant endophyte Kosakonia sp. strain KO348. LoxR modeling and biochemical studies demonstrated that LoxR binds N-acyl homoserine lactones (AHLs) in a promiscuous way. PsrR, on the other hand, belongs to the subfamily of plant-associated-bacterium (PAB) LuxR solos that respond to plant compounds. Target promoter studies as well as modeling and phylogenetic comparisons suggest that PAB LuxR solos are likely to respond to different plant compounds. Finally, LoxR is involved in the regulation of T6SS and PsrR plays a role in root endosphere colonization. IMPORTANCE Cell-cell signaling in bacteria allows a synchronized and coordinated behavior of a microbial community. LuxR solos represent a subfamily of proteins in proteobacteria which most commonly detect and respond to signals produced exogenously by other microbes or eukaryotic hosts. Here, we report that a plant-beneficial bacterial endophyte belonging to the novel genus of Kosakonia possesses two LuxR solos; one is involved in the detection of exogenous N-acyl homoserine lactone quorum sensing signals and the other in detecting a compound(s) produced by the host plant. These two Kosakonia LuxR solos are therefore most likely involved in interspecies and interkingdom signaling.

scholarly journals A Rhodococcus qsdA-Encoded Enzyme Defines a Novel Class of Large-Spectrum Quorum-Quenching Lactonases

2008 ◽  
Vol 74 (5) ◽  
pp. 1357-1366 ◽  
Author(s):  
Stéphane Uroz ◽  
Phil M. Oger ◽  
Emilie Chapelle ◽  
Marie-Thérèse Adeline ◽  
Denis Faure ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Genomic Library ◽  
Acyl Chain ◽  
Rhodococcus Erythropolis ◽  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Degrading Enzymes ◽  
Regulated Functions ◽  
The Relationship

ABSTRACT A gene involved in N-acyl homoserine lactone (N-AHSL) degradation was identified by screening a genomic library of Rhodococcus erythropolis strain W2. This gene, named qsdA (for quorum-sensing signal degradation), encodes an N-AHSL lactonase unrelated to the two previously characterized N-AHSL-degrading enzymes, i.e., the lactonase AiiA and the amidohydrolase AiiD. QsdA is related to phosphotriesterases and constitutes the reference of a novel class of N-AHSL degradation enzymes. It confers the ability to inactivate N-AHSLs with an acyl chain ranging from C6 to C14, with or without substitution at carbon 3. Screening of a collection of 15 Rhodococcus strains and strains closely related to this genus clearly highlighted the relationship between the ability to degrade N-AHSLs and the presence of the qsdA gene in Rhodococcus. Bacteria harboring the qsdA gene interfere very efficiently with quorum-sensing-regulated functions, demonstrating that qsdA is a valuable tool for developing quorum-quenching procedures.

scholarly journals Identification and chemical characterization of N-acyl-homoserine lactone quorum sensing signals across sponge species and time

2017 ◽  
Vol 94 (2) ◽  
Author(s):  
Maya Britstein ◽  
Kumar Saurav ◽  
Roberta Teta ◽  
Gerardo Della Sala ◽  
Rinat Bar-Shalom ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Chemical Characterization ◽  
Homoserine Lactone ◽  
Sponge Species ◽  
Acyl Homoserine Lactone ◽  
Quorum Sensing Signals

scholarly journals The GCR1 and GPA1 Participate in Promotion of Arabidopsis Primary Root Elongation Induced by N-Acyl-Homoserine Lactones, the Bacterial Quorum-Sensing Signals

2012 ◽  
Vol 25 (5) ◽  
pp. 677-683 ◽  
Author(s):  
Fang Liu ◽  
Ziriu Bian ◽  
Zhenhua Jia ◽  
Qian Zhao ◽  
Shuishan Song
Keyword(s):  
Quorum Sensing ◽  
Root Elongation ◽  
Primary Root ◽  
Homoserine Lactone ◽  
Collective Behaviors ◽  
Homoserine Lactones ◽  
Acyl Homoserine Lactones ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum ◽  
Quorum Sensing Signals

Many gram-negative bacteria use N-acyl-homoserine lactones (AHL) as quorum-sensing signals to coordinate their collective behaviors. Accumulating evidence indicates that plants can respond to AHL. However, little is known about the molecular mechanism of plants reacting to these bacterial signals. In this study, we show that the treatment of Arabidopsis roots with N-3-oxo-hexanoyl-homoserine lactone (3OC6-HSL) and N-3-oxo-octanoyl-homoserine lactone (3OC8-HSL) resulted in significant root elongation. The genetic analysis revealed that the T-DNA insertional mutants of gcr1, encoding a G-protein-coupled receptor GCR1, were insensitive to 3OC6-HSL or 3OC8-HSL in assays of root growth. The loss-of-function mutants of the sole canonical Gα subunit GPA1 showed no response to AHL promotion of root elongation whereas Gα gain-of-function plants overexpressing either the wild type or a constitutively active version of Arabidopsis Gα exhibited the exaggerated effect on root elongation caused by AHL. Furthermore, the expression of GCR1 and GPA1 were significantly upregulated after plants were contacted with both AHL. Taken together, our results suggest that GCR1 and GPA1 are involved in AHL-mediated elongation of Arabidopsis roots. This provides insight into the mechanism of plant responses to bacterial quorum-sensing signals.

scholarly journals Octanoyl-Homoserine Lactone Is the Cognate Signal for Burkholderia mallei BmaR1-BmaI1 Quorum Sensing

2007 ◽  
Vol 189 (14) ◽  
pp. 5034-5040 ◽  
Author(s):  
Breck A. Duerkop ◽  
Ricky L. Ulrich ◽  
E. Peter Greenberg
Keyword(s):  
Quorum Sensing ◽  
Promoter Region ◽  
Homoserine Lactone ◽  
Burkholderia Mallei ◽  
Homoserine Lactones ◽  
E Coli ◽  
Cognate Receptor ◽  
System A ◽  
Acyl Homoserine Lactones ◽  
Quorum Sensing Signals

ABSTRACT Acyl-homoserine lactones (HSLs) serve as quorum-sensing signals for many Proteobacteria. Members of the LuxI family of signal generators catalyze the production of acyl-HSLs, which bind to a cognate receptor in the LuxR family of transcription factors. The obligate animal pathogen Burkholderia mallei produces several acyl-HSLs, and the B. mallei genome has four luxR and two luxI homologs, each of which has been established as a virulence factor. To begin to delineate the relevant acyl-HSL signals for B. mallei LuxR homologs, we analyzed the BmaR1-BmaI1 system. A comparison of acyl-HSL profiles from B. mallei ATCC 23344 and a B. mallei bmaI1 mutant indicates that octanoyl-HSL synthesis is BmaI1 dependent. Furthermore, octanoyl-HSL is the predominant acyl-HSL produced by BmaI1 in recombinant Escherichia coli. The synthesis of soluble BmaR1 in recombinant E. coli requires octanoyl-HSL or decanoyl-HSL. Insoluble aggregates of BmaR1 are produced in the presence of other acyl-HSLs and in the absence of acyl-HSLs. The bmaI1 promoter is activated by BmaR1 and octanoyl-HSL, and a 20-bp inverted repeat in the bmaI1 promoter is required for bmaI1 activation. Purified BmaR1 binds to this promoter region. These findings implicate octanoyl-HSL as the signal for BmaR1-BmaI1 quorum sensing and show that octanoyl-HSL and BmaR1 activate bmaI1 transcription.

scholarly journals Novel Bifunctional Acylase from Actinoplanes utahensis: A Versatile Enzyme to Synthesize Antimicrobial Compounds and Use in Quorum Quenching Processes

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 922
Author(s):  
Lara Serrano-Aguirre ◽  
Rodrigo Velasco-Bucheli ◽  
Begoña García-Álvarez ◽  
Ana Saborido ◽  
Miguel Arroyo ◽  
...  
Keyword(s):  
Quorum Quenching ◽  
Homoserine Lactone ◽  
Homoserine Lactones ◽  
Natural Analog ◽  
Acylhomoserine Lactone ◽  
Penicillin V ◽  
Communication Processes ◽  
Hydrolysis Of ◽  
Potential Use

Many intercellular communication processes, known as quorum sensing (QS), are regulated by the autoinducers N-acyl-l-homoserine lactones (AHLs) in Gram-negative bacteria. The inactivation of these QS processes using different quorum quenching (QQ) strategies, such as enzymatic degradation of the autoinducers or the receptor blocking with non-active analogs, could be the basis for the development of new antimicrobials. This study details the heterologous expression, purification, and characterization of a novel N-acylhomoserine lactone acylase from Actinoplanes utahensis NRRL 12052 (AuAHLA), which can hydrolyze different natural penicillins and N-acyl-homoserine lactones (with or without 3-oxo substitution), as well as synthesize them. Kinetic parameters for the hydrolysis of a broad range of substrates have shown that AuAHLA prefers penicillin V, followed by C12-HSL. In addition, AuAHLA inhibits the production of violacein by Chromobacterium violaceum CV026, confirming its potential use as a QQ agent. Noteworthy, AuAHLA is also able to efficiently synthesize penicillin V, besides natural AHLs and phenoxyacetyl-homoserine lactone (POHL), a non-natural analog of AHLs that could be used to block QS receptors and inhibit signal of autoinducers, being the first reported AHL acylase capable of synthesizing AHLs.

scholarly journals Synthesis of N-Acyl Homoserine Lactone Analogues Reveals Strong Activators of SdiA, the Salmonella enterica Serovar Typhimurium LuxR Homologue

2006 ◽  
Vol 73 (2) ◽  
pp. 535-544 ◽  
Author(s):  
Joost C. A. Janssens ◽  
Kristine Metzger ◽  
Ruth Daniels ◽  
Dave Ptacek ◽  
Tine Verhoeven ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Vibrio Fischeri ◽  
Acyl Chain ◽  
Homoserine Lactone ◽  
Gram Negative Bacteria ◽  
Ligand Interaction ◽  
Homoserine Lactones ◽  
Serovar Typhimurium

ABSTRACT N-Acyl homoserine lactones (AHLs) are molecules that are synthesized and detected by many gram-negative bacteria to monitor the population density, a phenomenon known as quorum sensing. Salmonella enterica serovar Typhimurium is an exceptional species since it does not synthesize its own AHLs, while it does encode a LuxR homologue, SdiA, which enables this bacterium to detect AHLs that are produced by other species. To obtain more information about the specificity of the ligand binding by SdiA, we synthesized and screened a limited library of AHL analogues. We identified two classes of analogues that are strong activators of SdiA: the N-(3-oxo-acyl)-homocysteine thiolactones (3O-AHTLs) and the N-(3-oxo-acyl)-trans-2-aminocyclohexanols. To our knowledge, this is the first report of compounds (the 3O-AHTLs) that are able to activate a LuxR homologue at concentrations that are lower than the concentrations of the most active AHLs. SdiA responds with greatest sensitivity to AHTLs that have a keto modification at the third carbon atom and an acyl chain that is seven or eight carbon atoms long. The N-(3-oxo-acyl)-trans-2-aminocyclohexanols were found to be less sensitive to deactivation by lactonase and alkaline pH than the 3O-AHTLs and the AHLs are. We also examined the activity of our library with LuxR of Vibrio fischeri and identified three new inhibitors of LuxR. Finally, we performed preliminary binding experiments which suggested that SdiA binds its activators reversibly. These results increase our understanding of the specificity of the SdiA-ligand interaction, which could have uses in the development of anti-quorum-sensing-based antimicrobials.

scholarly journals A Marine Mesorhizobium sp. Produces Structurally Novel Long-Chain N-Acyl-l-Homoserine Lactones

2007 ◽  
Vol 73 (11) ◽  
pp. 3587-3594 ◽  
Author(s):  
Anja Krick ◽  
Stefan Kehraus ◽  
Leo Eberl ◽  
Kathrin Riedel ◽  
Heidrun Anke ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Solid Phase ◽  
Homoserine Lactone ◽  
Signal Molecules ◽  
Cytotoxic Activities ◽  
Rrna Gene ◽  
Liquid Chromatography Mass Spectrometry ◽  
Homoserine Lactones ◽  
Chain Lengths ◽  
Acylated Homoserine Lactones

ABSTRACT Our study focused on a Mesorhizobium sp. that is phylogenetically affiliated by 16S rRNA gene sequence to other marine and saline bacteria of this genus. Liquid chromatography-mass spectrometry investigations of the extract obtained from solid-phase extraction of cultures of this bacterium indicated the presence of several N-acyl homoserine lactones (AHLs), with chain lengths of C10 to C16. Chromatographic separation of the active bacterial extract yielded extraordinarily large amounts of two unprecedented acylated homoserine lactones, 5-cis-3-oxo-C12-homoserine lactone (5-cis-3-oxo-C12-HSL) (compound 1) and 5-cis-C12-HSL (compound 2). Quorum-sensing activity of compounds 1 and 2 was shown in two different biosensor systems [Escherichia coli MT102(pSB403) and Pseudomonas putida F117(pKR-C12)]. Furthermore, it was shown that both compounds can restore protease and pyoverdin production of an AHL-deficient Pseudomonas aeruginosa PAO1 lasI rhlI double mutant, suggesting that these signal molecules maybe used for intergenus signaling. In conclusion, these data indicate that the quorum-sensing activity of compounds 1 and 2 is modulated by the chain length and functional groups of the acyl moiety. Additionally, compound 1 showed antibacterial and cytotoxic activities.

scholarly journals Identification of Catechin as One of the Flavonoids from Combretum albiflorum Bark Extract That Reduces the Production of Quorum-Sensing-Controlled Virulence Factors in Pseudomonas aeruginosa PAO1

2009 ◽  
Vol 76 (1) ◽  
pp. 243-253 ◽  
Author(s):  
Olivier M. Vandeputte ◽  
Martin Kiendrebeogo ◽  
Sanda Rajaonson ◽  
Billo Diallo ◽  
Adeline Mol ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Higher Plants ◽  
Homoserine Lactone ◽  
Bark Extract ◽  
Negative Effect ◽  
Virulence Factor Production

ABSTRACT Quorum-sensing (QS) regulates the production of key virulence factors in Pseudomonas aeruginosa and other important pathogenic bacteria. In this report, extracts of leaves and bark of Combretum albiflorum (Tul.) Jongkind (Combretaceae) were found to quench the production of QS-dependent factors in P. aeruginosa PAO1. Chromatographic fractionation of the crude active extract generated several active fractions containing flavonoids, as shown by their typical spectral features. Purification and structural characterization of one of the active compounds led to the identification of the flavan-3-ol catechin [(2R,3S)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol]. The identity of catechin as one of the active molecules was confirmed by comparing the high-pressure liquid chromatography profiles and the mass spectrometry spectra obtained for a catechin standard and for the active C. albiflorum fraction. Moreover, standard catechin had a significant negative effect on pyocyanin and elastase productions and biofilm formation, as well as on the expression of the QS-regulated genes lasB and rhlA and of the key QS regulatory genes lasI, lasR, rhlI, and rhlR. The use of RhlR- and LasR-based biosensors indicated that catechin might interfere with the perception of the QS signal N-butanoyl-l-homoserine lactone by RhlR, thereby leading to a reduction of the production of QS factors. Hence, catechin, along with other flavonoids produced by higher plants, might constitute a first line of defense against pathogenic attacks by affecting QS mechanisms and thereby virulence factor production.

Sign in / Sign up

Export Citation Format

Share Document