Identification of a Novel Bacteriocin Regulatory System in Streptococcus mutans
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ABSTRACT:
ORGANISM(S): Streptococcus mutans
PROVIDER: GSE22902 | GEO | 2010/08/15
SECONDARY ACCESSION(S): PRJNA127951
REPOSITORIES: GEO
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Project description:Recently, we described the function of a novel two-gene regulatory system consisting of a LytTR family transcription regulator and a membrane protein, which we referred to as the hdrRM operon. We determined that the HdrRM system controls the expression of another similar regulatory system annotated as SMU.2080 and SMU.2081. Like hdrRM, the SMU.2080 – 2081 operon encodes a LytTR family transcription regulator and membrane protein, which we now refer to as BrsR and BrsM, respectively. In this study, we used microarray to examine the regulatory role of BrsR and found that it functions as a transcription activator for a variety of bacteriocins and bacteriocin-related genes. Streptococcus mutans UA140 derivatives, lacA ( genotype: ΔbrsRM /pFW5::PlacA ) and lacA2080 (genotype:ΔbrsRM /pFW5::PlacA-brsR), were cultivated overnight at 37°C in a chemically-defined medium containing 0.5% (wt/vol) glucose as carbon source . The overnight cultures were diluted 1:30 in CDM with 1% (wt/vol) lactose in a total volume of 30 ml. The cells were allowed to grow to an optical density at 600 nm of 0.3 and RNA was extracted. The transcriptional profile of the whole genome was examined with microarray.
2010-08-14 | E-GEOD-22902 | biostudies-arrayexpress
Project description:A popular strategy for enhancing the antibacterial properties of probiotic bacteria is to retrofit them with the ability to overproduce heterologous bacteriocins. This is often achieved from strong, non-native promoters. How the dysregulated overproduction of heterologous bacteriocins affects the fitness and antibacterial efficacy of the retrofitted probiotic bacteria is often overlooked. We conferred the prototypical probiotic Escherichia coli strain Nissle (EcN) the ability to produce different amounts of the bacteriocin microcin C (McC). Expression of the bacteriocin synthesis genes was driven from the native promoter (Pmcc-WT), or from promoters manipulated to be stronger (Pmcc-High) and weaker (Pmcc-Low) than the WT, in a plasmid-based system. Pmcc-Low and Pmcc-High retained their native regulation. A strain harbouring a non-functional promoter (Pmcc-Mut) produces no McC and was used as a control. Each strain was grown to early stationary phase, when production of McC starts, in Luria-Bertani broth at 37 degrees. The RNA was isolated and the effects of different levels of production of McC on the transcriptome of EcN was examined by RNA-Seq.
2023-06-30 | E-MTAB-13078 | biostudies-arrayexpress
Project description:Bacteriocins are natural antimicrobial peptides produced by a bacterium to kill closely related competitors. Streptococcus gallolyticus subsp. gallolyticus (Sgg) UCN34 produces a two-component bacteriocin named gallocin to colonize the gut by killing resident enterococci. In the present work, we investigated how gallocin was regulated by deleting individually three genes present in the locus and encoding potentially an inducing peptide (gsp), a histidine kinase (ghk) and a LytTR-containing response regulator (grr). Comparative transcriptional analyses of these three mutants as compared to the WT UCN34 showed that this 3- component regulatory system induces the transcription of the whole gallocin locus encoding gallocin but also five others putative bacteriocins and genes necessary for bacteriocins biosynthesis and secretion. Beside gallocin locus, only two other pairs of genes were coordinately induced in Sgg genome, encoding an ABC transporter and hypothetical proteins. We conclude that this regulatory system appears highly specialized in bacteriocins induction in Sgg UCN34.
2020-12-04 | GSE148401 | GEO
Project description:The two-component system (TCS) is a specific regulatory system in bacteria and plays an important role in sensing and adapting to the environment. In this study, we evaluated the roles of TCSs in the major cariogenic pathogen Streptococcus mutans in resistance to several types of bacteriocin. In a comprehensive analysis using individual TCS mutants, we found that two novel TCSs were associated with resistance against distinct lantibiotics nisin A (class I type A[I]) and nukacin ISK-1(class I type A[II]). One TCS, SMU.659-660 (designated as NsrRS), was related to resistance against nisin A produced by Lactococcus lactis ATCC 11454. The other TCS, SMU.1146-1145 (designated as LcrRS), was related to resistance against nukacin ISK-1 produced by Staphylococcus warneri ISK-1. NsrRS induced the expression of SMU.658 (designated as NsrX), which constitutes an operon with nsrRS, in response to nisin A. Inactivation of nsrX increased susceptibility to nisin A. Additionally, NsrX expression in S. mutans increased the binding affinity to nisin A compared to a no-expression strain. LcrRS induced the expression of SMU.1148-50 (lctFEG), which encodes an ABC transporter and is located upstream of lcrRS, in response to nukacin ISK-1. Inactivation of lctFEG significantly increased susceptibility to nukacin ISK-1. Electrophoretic mobility shift assay analysis revealed that NsrR and LcrR bound directly to regions upstream of nsrX and lctFEG, respectively. This is the first report that two distinct TCSs, NsrRS and LcrRS, are independently involved in resistance to nisin A and nukacin ISK-1 in S. mutans.
2013-12-31 | GSE44602 | GEO
Project description:The two-component system (TCS) is a specific regulatory system in bacteria and plays an important role in sensing and adapting to the environment. In this study, we evaluated the roles of TCSs in the major cariogenic pathogen Streptococcus mutans in resistance to several types of bacteriocin. In a comprehensive analysis using individual TCS mutants, we found that two novel TCSs were associated with resistance against distinct lantibiotics nisin A (class I type A[I]) and nukacin ISK-1(class I type A[II]). One TCS, SMU.659-660 (designated as NsrRS), was related to resistance against nisin A produced by Lactococcus lactis ATCC 11454. The other TCS, SMU.1146-1145 (designated as LcrRS), was related to resistance against nukacin ISK-1 produced by Staphylococcus warneri ISK-1. NsrRS induced the expression of SMU.658 (designated as NsrX), which constitutes an operon with nsrRS, in response to nisin A. Inactivation of nsrX increased susceptibility to nisin A. Additionally, NsrX expression in S. mutans increased the binding affinity to nisin A compared to a no-expression strain. LcrRS induced the expression of SMU.1148-50 (lctFEG), which encodes an ABC transporter and is located upstream of lcrRS, in response to nukacin ISK-1. Inactivation of lctFEG significantly increased susceptibility to nukacin ISK-1. Electrophoretic mobility shift assay analysis revealed that NsrR and LcrR bound directly to regions upstream of nsrX and lctFEG, respectively. This is the first report that two distinct TCSs, NsrRS and LcrRS, are independently involved in resistance to nisin A and nukacin ISK-1 in S. mutans. Total of 14 samples were analyzed. Total RNA from each test strain and control described below were labeled with Alexa Fluor® 555 and Alexa Fluor® 647, respectively, and were cohybridized on a single array. Labeling and hybridization were performed once or twice independently. UA159 wild type as control vs. UA159 with nisinA or nukacin ISK-1, UA159 wild type with nisinA or nukacin ISK-1 vs. nsrRS or lcrRS deletion mutant in UA159 with nisinA or nukacin ISK-1.
2013-12-31 | E-GEOD-44602 | biostudies-arrayexpress
Project description:Subclass IIa bacteriocins have strong antilisterial activity and can control the growth of Listeria monocytogenes in food. However, L. monocytogenes may develop resistance towards such bacteriocins. In this follow-up study, the transcriptomes of a high level (L502-1) and a low level (L502-6) spontaneous sakacin P-resistant mutant strain of L. monocytogenes were compared to the wild-type (L502). The growth of the resistant strains was reduced on mannose but not affected on cellobiose and the transcriptomics was performed during growth on these sugars. The mannose phosphotransferase system (PTS) encoded by the mptACD operon (mpt) is known for transporting mannose and also act as a receptor to class IIa bacteriocins. The mpt was repressed in L502-1 and this is in accordance with abolition of the bacteriocin receptor with resistance to class IIa bacteriocins. In contrast, the mpt was induced in L502-6. Despite the induction of the mpt, L502-6 showed 1,000 times more resistance phenotype and reduced growth on mannose suggesting the mannose-PTS may not be functional in L502-6. The microarray data suggests the presence of other transcriptional responses that may be linked to the sakacin P resistance phenotype particularly in L502-6. Most of commonly regulated genes encode proteins involved in transport and energy metabolism. The resistant strains displayed shift in general carbon catabolite control possibly mediated by the mpt. Our data suggest that the resistant strains may have a reduced virulence potential. Growth sugar- and mutant-specific responses were also revealed. The two resistant strains also displayed difference in stability of the sakacin P resistance phenotype, growth in the presence of both the lytic bacteriophage P100 and activated charcoal. Taken together, the present study showed that a single time exposure to the class IIa bacteriocin sakacin P may elicit contrasting phenotypic and transcriptome responses in L. monocytogenes possibly through regulation of the mpt. Data is also available from <ahref=http://bugs.sgul.ac.uk/E-BUGS-110 target=_blank>BuG@Sbase</a>
2011-04-15 | E-BUGS-110 | biostudies-arrayexpress
Project description:Gut microbiota is an unignored target in maintaining intestinal homeostasis due to its regulatory effects on intestinal health through multiple mechanisms, including enhancing intestinal barriers, modulating microbial diversity, secreting various metabolites, etc. Bacteriocins produced by probiotics have been gradually proved vital for intestinal diseases intervention, however, the corresponding mechanisms have received less attention and the whole story of their regulative activities are hard to be fully uncovered. The two-peptide Plantaricin NC8 (PLNC8), coded by gene plnc8, is a bacteriocin ubiquitously produced by Lactobacillus plantarum, has been regarded as the potential vital bacteriocin for the anti-inflammatory effects of Lactobacillus plantarum. This study exploited CRISPR-cas9 and prokaryotic gene overexpression techniques to construct the plnc8 strains for the anti-inflammatory mechanism investigation. Based on the metagenomics, transcriptomics and metabolomics analysis, the anti-enteritis mechanism of PLNC8 systematically in DSS-induced enteritis models were comprehensively revealed. PLNC8 induced alterations in the composition of gut microbiota composition, promoting the alterations of multiple probiotics such as Eubacterium plexicaudatum, Doreasp.5-2, Enterococcus cecorum and Prevotella oulorum. Besides, various metabolites produced by the gut microbiota were influenced, and the key metabolites of xanthine, hypoxanthine, and L-histidine were regulated via purine and histidine metabolic pathways. These metabolites further inhibited p38 MAPK phosphorylation of enterocytes induced by DSS. Ultimately, the intestinal barrier repairment and anti- enteritis were achieved, proving the anti-enteritis effects of PLNC8 via microbe-metabolites-enterocyte axis.
2024-08-20 | GSE274981 | GEO
Project description:Most bacteria are in fierce competition with other species for limited nutrients. Some bacteria can kill nearby cells by secreting bacteriocins, a diverse group of proteinaceous antimicrobials. However, bacteriocins are typically freely diffusible, and so of little value to planktonic cells in aqueous environments. Here, we identify an atypical two-protein bacteriocin in the gamma-proteobacterium Caulobacter crescentus that is retained on the surface of producer cells where it mediates cell contact-dependent killing. The bacteriocin-like proteins CdzC and CdzD harbor glycine-zipper motifs, often found in amyloids, and CdzC forms large, insoluble aggregates on the surface of producer cells. These aggregates can drive contact-dependent killing of other organisms, or Caulobacter cells not producing the CdzIE immunity protein. The Cdz system uses a type I secretion system and is unrelated to previously described contact-dependent inhibition systems. However, Cdz-like systems are found in many bacteria, suggesting that this form of contact-dependent inhibition is common.
2017-05-03 | GSE96582 | GEO
Project description:Biosynthetic gene clusters (BGCs) encoding the production of bacteriocins are widespread amongst bacterial isolates and are important genetic determinants of competitive fitness. Staphylococci produce a tremendous diversity of compounds and the corresponding gene clusters (Staphylococcal Antibiosis Islands - SAbIs) are frequently associated with mobile genetic elements, suggesting acquisition and loss of biosynthetic capacity. Pharmaceutical biology has shown that transfer of BGCs between bacterial species is frequently challenging and production by the heterologous hosts often depends on optimal precursor supplies. It is unknown if transfer of SAbIs has similar effects. We modelled SAbItransfer between closely related S. aureus strains based on the SAbI encoding the ribosomally synthesized and post-translationally modified peptide (RiPP) Micrococcin P1 (MP1). Our results indicate that acquisition of SAbIs can represent a mixed blessing for the recipient strain and its genetic and metabolic predispositions are of crucial importance to integrate bacteriocin production into the cellular metabolism.
2022-11-21 | PXD035193 | Pride
Project description:Background: Treponema denticola is strongly associated with the development of periodontal disease. Both synergistic and antagonistic effects are observed among bacterial species in the process of biofilm formation. Bacteriocin-related genes have not yet been fully characterized in periodontopathic bacteria. The aim of this study was to detect and characterize bacteriocin-associated proteins in T. denticola. Methods: The whole genome sequence of T. denticola ATCC 35405 was screened with a Streptococcus mutans bacteriocin immunity protein (ImmA/Bip) sequence. The prevalence of homologous genes in T. denticola strains was then investigated by Southern blotting. Expression of the genes was evaluated by qRT-PCR. Results: In the genome sequence of T. denticola, an amino acid sequence coded by open reading frame TDE_0719 showed 26% identity with the S. mutans ImmA. Furthermore, two protein sequences coded by TDE_0425 and TDE_2431 in T. denticola ATCC 35405 showed ~40% identity with that coded by TDE0719. Therefore, TDE_0425, TDE_0719, and TDE_2431 were designated as tepA1, A2, and A3, respectively. Open reading frames showing similarity to the HlyD family of secretion proteins were detected downstream of tepA1, A2, and A3. They were designated as tepB1, B2, and B3, respectively. A gene harboring a bacteriocin-like signal sequence was detected upstream of tepA1. The prevalence of tepA1 and A2 differed among Treponema species. Susceptibility to chloramphenicol and ofloxiacin was slightly decreased in a tepA2 mutant while that to kanamycin was increased. Expression of tepA3-B3 was increased in the tepA2 mutant. Conclusion: These results indicate that T. denticola ATCC 35405 has three potential bacteriocin export proteins and that the presence of these genes differs among the Treponema strains. These proteins may be involved in resistance to chloramphenicol.
2017-01-01 | GSE83445 | GEO