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Li J, Wang Y, Du Y, Zhang H, Fan Q, Sun L, Yi L, Wang S, Wang Y. mRNA-Seq reveals the quorum sensing system luxS gene contributes to the environmental fitness of Streptococcus suis type 2. BMC Microbiol 2021; 21:111. [PMID: 33849451 PMCID: PMC8045309 DOI: 10.1186/s12866-021-02170-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/31/2021] [Indexed: 12/22/2022] Open
Abstract
Background Streptococcus suis type 2 (SS2) is an important zoonotic pathogen. We have previously reported the structure of LuxS protein and found that the luxS gene is closely related to biofilm, virulence gene expression and drug resistance of SS2. However, the mechanism of luxS mediated SS2 stress response is unclear. Therefore, this experiment performed stress response to luxS mutant (ΔluxS) and complement strain (CΔluxS), overexpression strain (luxS+) and wild-type SS2 strain HA9801, and analyzed the differential phenotypes in combination with transcriptome data. Results The results indicate that the luxS gene deletion causes a wide range of phenotypic changes, including chain length. RNA sequencing identified 278 lx-regulated genes, of which 179 were up-regulated and 99 were down-regulated. Differential genes focus on bacterial growth, stress response, metabolic mechanisms and drug tolerance. Multiple mitotic genes were down-regulated; while the ABC transporter system genes, cobalamin /Fe3+-iron carrier ABC transporter ATPase and oxidative stress regulators were up-regulated. The inactivation of the luxS gene caused a significant reduction in the growth and survival in the acid (pH = 3.0, 4.0, 5.0) and iron (100 mM iron chelator 2,2′-dipyridyl) stress environments. However, the mutant strain ΔluxS showed increased antioxidant activity to H2O2 (58.8 mmol/L). Conclusions The luxS gene in SS2 appears to play roles in iron metabolism and protective responses to acidic and oxidative environmental conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02170-w.
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Affiliation(s)
- Jinpeng Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Yanbin Du
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Hui Zhang
- China Animal Health and Epidemiology Center, Qingdao, China
| | - Qingying Fan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Liyun Sun
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China.,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China
| | - Li Yi
- College of Life Science, Luoyang Normal University, Luoyang, China
| | - Shaohui Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, China. .,Key Laboratory of Molecular Pathogen and Immunology of Animal of Luoyang, Luoyang, China.
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The Role of luxS in Histophilus somni Virulence and Biofilm Formation. Infect Immun 2021; 89:IAI.00567-20. [PMID: 33139386 DOI: 10.1128/iai.00567-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 10/29/2020] [Indexed: 01/09/2023] Open
Abstract
S-Ribosylhomocysteinase (LuxS) is required for the synthesis of the autoinducer-2 (AI-2) quorum-sensing signaling molecule in many Gram-negative bacteria. The bovine (and ovine) opportunistic pathogen Histophilus somni contains luxS and forms a biofilm containing an exopolysaccharide (EPS) in the matrix. Since biofilm formation is regulated by quorum sensing in many bacteria, the roles of luxS in H. somni virulence and biofilm formation were investigated. Although culture supernatants from H. somni were ineffective at inducing bioluminescence in the Vibrio harveyi reporter strain BB170, H. somni luxS complemented the biosynthesis of AI-2 in the luxS-deficient Escherichia coli strain DH5α. H. somni strain 2336 luxS was inactivated by transposon mutagenesis. RNA expression profiles revealed that many genes were significantly differentially expressed in the luxS mutant compared to that in the wild-type, whether the bacteria were grown planktonically or in a biofilm. Furthermore, the luxS mutant had a truncated and asialylated lipooligosaccharide (LOS) and was substantially more serum sensitive than the wild-type. Not surprisingly, the luxS mutant was attenuated in a mouse model for H. somni virulence, and some of the altered phenotypes were partially restored after the mutation was complemented with a functional luxS However, no major differences were observed between the wild-type and the luxS mutant in regard to outer membrane protein profiles, biofilm formation, EPS production, or intracellular survival. These results indicate that luxS plays a role in H. somni virulence in the context of LOS biosynthesis but not biofilm formation or other phenotypic properties examined.
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Zhang B, Ku X, Zhang X, Zhang Y, Chen G, Chen F, Zeng W, Li J, Zhu L, He Q. The AI-2/ luxS Quorum Sensing System Affects the Growth Characteristics, Biofilm Formation, and Virulence of Haemophilus parasuis. Front Cell Infect Microbiol 2019; 9:62. [PMID: 30941317 PMCID: PMC6434701 DOI: 10.3389/fcimb.2019.00062] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Haemophilus parasuis (H. parasuis) is a kind of opportunistic pathogen of the upper respiratory tract of piglets. Under certain circumstances, virulent strains can breach the mucosal barrier and enter the bloodstream, causing severe Glässer's disease. Many virulence factors are found to be related to the pathogenicity of H. parasuis strain, but the pathogenic mechanism remains unclear. LuxS/AI-2, as a kind of very important quorum sensing system, affects the growth characteristics, biofilm formation, antibiotic production, virulence, and metabolism of different strains. In order to investigate the effect of luxS/AI-2 quorum sensing system on the virulence of H. parasuis, a deletion mutant strain (ΔluxS) and complemented strain (C-luxS) were constructed and characterized. The results showed that the luxS gene participated in regulating and controlling stress resistance, biofilm formation and virulence. Compared with wild-type strain, ΔluxS strain decreased the production of AI-2 molecules and the tolerance toward oxidative stress and heat shock, and it reduced the abilities of autoagglutination, hemagglutination, and adherence, whereas it increased the abilities to form biofilm in vitro. In vivo experiments showed that ΔluxS strain attenuated its virulence about 10-folds and significantly decreased its tissue burden of bacteria in mice, compared with the wild-type strain. Taken together, the luxS/AI-2 quorum sensing system in H. parasuis not only plays an important role in growth and biofilm formation, but also affects the pathogenicity of H. parasuis.
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Affiliation(s)
- Bingzhou Zhang
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xugang Ku
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xiaoqian Zhang
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yan Zhang
- College of Animal Sciences and Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Guo Chen
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Fangzhou Chen
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Wei Zeng
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jing Li
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Ling Zhu
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Qigai He
- State Key Laboratory of Agricultural Microbiology, Division of Animal Infectious Diseases, College of Animal Sciences and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
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Velusamy SK, Sampathkumar V, Godboley D, Fine DH. Survival of an Aggregatibacter actinomycetemcomitans quorum sensing luxS mutant in the mouths of Rhesus monkeys: insights into ecological adaptation. Mol Oral Microbiol 2017; 32:432-442. [PMID: 28383798 DOI: 10.1111/omi.12184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Experiments were designed to explore a prominent autoinducer-2 (AI-2) producing gene (luxS) related to colonization and survival of Aggregatibacter actinomycetemcomitans, a low abundance member of the indigenous flora, that forms a key component of the dysbiotic flora in localized aggressive periodontitis. The luxS gene was disrupted in a primate strain of A. actinomycetemcomitans before implantation into the oral cavity of Rhesus monkeys (Rh). The colonization efficiency of the luxS mutant (RhAa-VS4) was compared with the parental wild-type strain (RhAa3) (positive control) and a ltxA mutant (RhAa-VS2) (negative control). The in vivo results showed that the luxS mutation had minimal impact on A. actinomycetemcomitans colonization compared with the wild-type RhAa3 strain. In vitro studies revealed that there was a significant upregulation of attachment-related genes aae, apiA, and flp in the RhAa-VS4 strain compared with RhAa3. Biofilm forming ability was also significantly increased in the RhAa-VS4 strain compared with RhAa3, whereas the AI-2 signal was ablated. The exogenous addition of the AI-2 precursor dihydroxy pentanedione allowed the RhAa-VS4 strain to achieve RhAa3 biofilm levels. This is the first primate study to test the relevance of LuxS in vivo. In vitro assessment suggests that in vivo survival of the RhAa-VS4 strain was due to the production of signaling AI-2 molecules derived from other members of the flora as well as the upregulation of genes related to attachment and biofilm formation.
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Affiliation(s)
- Senthil K Velusamy
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
| | - Vandana Sampathkumar
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
| | - Dipti Godboley
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
| | - Daniel H Fine
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers University, Newark, NJ, USA
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Christiaen SEA, O'Connell Motherway M, Bottacini F, Lanigan N, Casey PG, Huys G, Nelis HJ, van Sinderen D, Coenye T. Autoinducer-2 plays a crucial role in gut colonization and probiotic functionality of Bifidobacterium breve UCC2003. PLoS One 2014; 9:e98111. [PMID: 24871429 PMCID: PMC4037206 DOI: 10.1371/journal.pone.0098111] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 04/29/2014] [Indexed: 01/13/2023] Open
Abstract
In the present study we show that luxS of Bifidobacterium breve UCC2003 is involved in the production of the interspecies signaling molecule autoinducer-2 (AI-2), and that this gene is essential for gastrointestinal colonization of a murine host, while it is also involved in providing protection against Salmonella infection in Caenorhabditis elegans. We demonstrate that a B. breve luxS-insertion mutant is significantly more susceptible to iron chelators than the WT strain and that this sensitivity can be partially reverted in the presence of the AI-2 precursor DPD. Furthermore, we show that several genes of an iron starvation-induced gene cluster, which are downregulated in the luxS-insertion mutant and which encodes a presumed iron-uptake system, are transcriptionally upregulated under in vivo conditions. Mutation of two genes of this cluster in B. breve UCC2003 renders the derived mutant strains sensitive to iron chelators while deficient in their ability to confer gut pathogen protection to Salmonella-infected nematodes. Since a functional luxS gene is present in all tested members of the genus Bifidobacterium, we conclude that bifidobacteria operate a LuxS-mediated system for gut colonization and pathogen protection that is correlated with iron acquisition.
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Affiliation(s)
| | - Mary O'Connell Motherway
- Alimentary Pharmabiotic Centre and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Francesca Bottacini
- Alimentary Pharmabiotic Centre and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Noreen Lanigan
- Alimentary Pharmabiotic Centre and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Pat G. Casey
- Alimentary Pharmabiotic Centre and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Geert Huys
- Laboratory of Microbiology & BCCM/LMG Bacteria Collection, Ghent University, Ghent, Belgium
| | - Hans J. Nelis
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Douwe van Sinderen
- Alimentary Pharmabiotic Centre and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
- * E-mail:
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Li L, Xu Z, Zhou Y, Li T, Sun L, Chen H, Zhou R. Analysis on Actinobacillus pleuropneumoniae LuxS regulated genes reveals pleiotropic roles of LuxS/AI-2 on biofilm formation, adhesion ability and iron metabolism. Microb Pathog 2011; 50:293-302. [PMID: 21320583 DOI: 10.1016/j.micpath.2011.02.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 01/31/2011] [Accepted: 02/04/2011] [Indexed: 12/20/2022]
Abstract
LuxS is an enzyme involved in the activated methyl cycle and the by-product autoinducer-2 (AI-2) was a quorum sensing signal in some species. In our previous study, the functional LuxS in AI-2 production was verified in the porcine respiratory pathogen Actinobacillus pleuropneumoniae. Enhanced biofilm formation and reduced virulence were observed in the luxS mutant. To comprehensively understand the luxS function, in this study, the transcriptional profiles were compared between the A. pleuropneumoniae luxS mutant and its parental strain in four different growth phases using microarray. Many genes associated with infection were differentially expressed. The biofilm formation genes pgaABC in the luxS mutant were up-regulated in early exponential phase, while 9 genes associated with adhesion were down-regulated in late exponential phase. A group of genes involved in iron acquisition and metabolism were regulated in four growth phases. Phenotypic investigations using luxS mutant and both genetic and chemical (AI-2) complementation on these virulence traits were performed. The results demonstrated that the luxS mutant showed enhanced biofilm formation and reduced adhesion ability and these effects were not due to lack of AI-2. But AI-2 could increase biofilm formation and adhesion of A. pleuropneumoniae independent of LuxS. Growth under iron restricted condition could be controlled by LuxS through AI-2 production. These results revealed pleiotropic roles of LuxS and AI-2 on A. pleuropneumoniae virulence traits.
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Affiliation(s)
- Lu Li
- Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Shizishan Street 1, Wuhan 430070, China
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Labandeira-Rey M, Janowicz DM, Blick RJ, Fortney KR, Zwickl B, Katz BP, Spinola SM, Hansen EJ. Inactivation of the Haemophilus ducreyi luxS gene affects the virulence of this pathogen in human subjects. J Infect Dis 2009; 200:409-16. [PMID: 19552526 DOI: 10.1086/600142] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Haemophilus ducreyi 35000HP contains a homologue of the luxS gene, which encodes an enzyme that synthesizes autoinducer 2 (AI-2) in other gram-negative bacteria. H. ducreyi 35000HP produced AI-2 that functioned in a Vibrio harveyi-based reporter system. A H. ducreyi luxS mutant was constructed by insertional inactivation of the luxS gene and lost the ability to produce AI-2. Provision of the H. ducreyi luxS gene in trans partially restored AI-2 production by the mutant. The luxS mutant was compared with its parent for virulence in the human challenge model of experimental chancroid. The pustule-formation rate in 5 volunteers was 93.3% (95% confidence interval, 81.7%-99.9%) at 15 parent sites and 60.0% (95% confidence interval, 48.3%-71.7%) at 15 mutant sites (1-tailed P < .001). Thus, the luxS mutant was partially attenuated for virulence. This is the first report of AI-2 production contributing to the pathogenesis of a genital ulcer disease.
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Affiliation(s)
- Maria Labandeira-Rey
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, USA
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Boyen F, Eeckhaut V, Van Immerseel F, Pasmans F, Ducatelle R, Haesebrouck F. Quorum sensing in veterinary pathogens: mechanisms, clinical importance and future perspectives. Vet Microbiol 2009; 135:187-95. [PMID: 19185433 DOI: 10.1016/j.vetmic.2008.12.025] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 12/23/2008] [Accepted: 12/24/2008] [Indexed: 11/27/2022]
Abstract
Under certain circumstances the individuals of a bacterial population may find advantages in acting together and making "collective decisions". This phenomenon is better known as quorum sensing. When the concentration of signal molecules produced by the surrounding bacteria exceeds a certain threshold, the bacterial population acts as a single organism, collectively expressing virulence genes, biofilm forming genes, etc. Several mechanisms of quorum sensing are discussed, each with its distinct signal molecules and respective receptors. Some of these mechanisms are restricted to sensing intraspecies signalling, but interspecies and even interkingdom signalling have also been described. Several veterinary pathogens such as Staphylococcus aureus, Staphylococcus pseudintermedius, Pseudomonas aeruginosa and Salmonella Typhimurium use quorum sensing as a means to optimize virulence gene expression and host colonization. Therefore, targeting of the QS mechanisms may provide a novel strategy for combating bacterial infections, also in veterinary medicine.
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Affiliation(s)
- F Boyen
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
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Li L, Zhou R, Li T, Kang M, Wan Y, Xu Z, Chen H. Enhanced biofilm formation and reduced virulence of Actinobacillus pleuropneumoniae luxS mutant. Microb Pathog 2008; 45:192-200. [PMID: 18585450 DOI: 10.1016/j.micpath.2008.05.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 05/19/2008] [Accepted: 05/23/2008] [Indexed: 11/30/2022]
Affiliation(s)
- Lu Li
- Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
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James CE, Hasegawa Y, Park Y, Yeung V, Tribble GD, Kuboniwa M, Demuth DR, Lamont RJ. LuxS involvement in the regulation of genes coding for hemin and iron acquisition systems in Porphyromonas gingivalis. Infect Immun 2006; 74:3834-44. [PMID: 16790755 PMCID: PMC1489751 DOI: 10.1128/iai.01768-05] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The periodontal pathogen Porphyromonas gingivalis employs a variety of mechanisms for the uptake of hemin and inorganic iron. Previous work demonstrated that hemin uptake in P. gingivalis may be controlled by LuxS-mediated signaling. In the present study, the expression of genes involved in hemin and iron uptake was determined in parent and luxS mutant strains by quantitative real-time reverse transcription-PCR. Compared to the parental strain, the luxS mutant showed reduced levels of transcription of genes coding for the TonB-linked hemin binding protein Tlr and the lysine-specific protease Kgp, which can degrade host heme-containing proteins. In contrast, there was up-regulation of the genes for another TonB-linked hemin binding protein, HmuR; a hemin binding lipoprotein, FetB; a Fe(2+) ion transport protein, FeoB1; and the iron storage protein ferritin. Differential expression of these genes in the luxS mutant was maximal in early-exponential phase, which corresponded with peak expression of luxS and AI-2 signal activity. Complementation of the luxS mutation with wild-type luxS in trans rescued expression of hmuR. Mutation of the GppX two-component signal transduction pathway caused an increase in expression of luxS along with tlr and lower levels of message for hmuR. Moreover, expression of hmuR was repressed, and expression of tlr stimulated, when the luxS mutant was incubated with AI-2 partially purified from the culture supernatant of wild-type cells. A phenotypic outcome of the altered expression of genes involved in hemin uptake was impairment of growth of the luxS mutant in hemin-depleted medium. The results demonstrate a role of LuxS/AI-2 in the regulation of hemin and iron acquisition pathways in P. gingivalis and reveal a novel control pathway for luxS expression.
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Affiliation(s)
- Chloe E James
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL 32610-0424, USA
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