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Kang H, Gan J, Zhao J, Kong W, Zhang J, Zhu M, Li F, Song Y, Qin J, Liang H. Crystal structure of Pseudomonas aeruginosa RsaL bound to promoter DNA reaffirms its role as a global regulator involved in quorum-sensing. Nucleic Acids Res 2016; 45:699-710. [PMID: 27924027 PMCID: PMC5314801 DOI: 10.1093/nar/gkw954] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 09/30/2016] [Accepted: 10/11/2016] [Indexed: 11/17/2022] Open
Abstract
Pseudomonas aeruginosa possesses at least three well-defined quorum-sensing (QS) (las, rhl and pqs) systems that control a variety of important functions including virulence. RsaL is a QS repressor that reduces QS signal production and ensures homeostasis by functioning in opposition to LasR. However, its regulatory role in signal homeostasis remains elusive. Here, we conducted a ChIP-seq assay and revealed that RsaL bound to two new targets, the intergenic regions of PA2228/PA2229 and pqsH/cdpR, which are required for PQS synthesis. Deletion of rsaL reduced transcription of pqsH and cdpR, thus decreasing PQS signal production. The ΔrsaL strain exhibited increased pyocyanin production and reduced biofilm formation, which are dependent on CdpR or PqsH activity. In addition, we solved the structure of the RsaL–DNA complex at a 2.4 Å resolution. Although the overall sequence similarity is quite low, RsaL folds into a HTH-like structure, which is conserved among many transcriptional regulators. Complementation results of the rsaL knockout cells with different rsaL mutants further confirmed the critical role of the DNA-binding residues (including Arg20, Gln27, Gln38, Gly35, Ser37 and Ser42) that are essential for DNA binding. Our findings reveal new targets of RsaL and provide insight into the detailed characterization of the RsaL–DNA interaction.
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Affiliation(s)
- Huaping Kang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Jianhua Gan
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Weina Kong
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Jing Zhang
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Miao Zhu
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Fan Li
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Yaqin Song
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Jin Qin
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, Shaanxi 710069, China
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Yu H, Xiong J, Zhang R, Hu X, Qiu J, Zhang D, Xu X, Xin R, He X, Xie W, Sheng H, Chen Q, Zhang L, Rao X, Zhang K. Ndk, a novel host-responsive regulator, negatively regulates bacterial virulence through quorum sensing in Pseudomonas aeruginosa. Sci Rep 2016; 6:28684. [PMID: 27345215 PMCID: PMC4921839 DOI: 10.1038/srep28684] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/08/2016] [Indexed: 11/09/2022] Open
Abstract
Pathogenic bacteria could adjust gene expression to enable their survival in the distinct host environment. However, the mechanism by which bacteria adapt to the host environment is not well described. In this study, we demonstrated that nucleoside diphosphate kinase (Ndk) of Pseudomonas aeruginosa is critical for adjusting the bacterial virulence determinants during infection. Ndk expression was down-regulated in the pulmonary alveoli of a mouse model of acute pneumonia. Knockout of ndk up-regulated transcription factor ExsA-mediated T3S regulon expression and decreased exoproduct-related gene expression through the inhibition of the quorum sensing hierarchy. Moreover, in vitro and in vivo studies demonstrated that the ndk mutant exhibits enhanced cytotoxicity and host pathogenicity by increasing T3SS proteins. Taken together, our data reveal that ndk is a critical novel host-responsive gene required for coordinating P. aeruginosa virulence upon acute infection.
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Affiliation(s)
- Hua Yu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, China.,Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Junzhi Xiong
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Rong Zhang
- Department of Pharmacy, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiaomei Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, China
| | - Jing Qiu
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Di Zhang
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiaohui Xu
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Rong Xin
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiaomei He
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Wei Xie
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Halei Sheng
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Qian Chen
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Le Zhang
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, China
| | - Kebin Zhang
- Central Laboratory, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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53
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Gu D, Guo M, Yang M, Zhang Y, Zhou X, Wang Q. A σE-Mediated Temperature Gauge Controls a Switch from LuxR-Mediated Virulence Gene Expression to Thermal Stress Adaptation in Vibrio alginolyticus. PLoS Pathog 2016; 12:e1005645. [PMID: 27253371 PMCID: PMC4890791 DOI: 10.1371/journal.ppat.1005645] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 04/28/2016] [Indexed: 01/15/2023] Open
Abstract
In vibrios, the expression of virulence factors is often controlled by LuxR, the master quorum-sensing regulator. Here, we investigate the interplay between LuxR and σE, an alternative sigma factor, during the control of virulence-related gene expression and adaptations to temperature elevations in the zoonotic pathogen Vibrio alginolyticus. An rpoE null V. alginolyticus mutant was unable to adapt to various stresses and was survival-deficient in fish. In wild type V. alginolyticus, the expression of LuxR-regulated virulence factors increased as the temperature was increased from 22°C to 37°C, but mutants lacking σE did not respond to temperature, indicating that σE is critical for the temperature-dependent upregulation of virulence genes. Further analyses revealed that σE binds directly to -10 and -35 elements in the luxR promoter that drive its transcription. ChIP assays showed that σE binds to the promoter regions of luxR, rpoH and rpoE at high temperatures (e.g., 30°C and 37°C). However, at higher temperatures (42°C) that induce thermal stress, σE binding to the luxR promoter decreased, while its binding to the rpoH and rpoE promoters was unchanged. Thus, the temperature-dependent binding of σE to distinct promoters appears to underlie a σE-controlled switch between the expression of virulence genes and adaptation to thermal stress. This study illustrates how a conserved temperature response mechanism integrates into quorum-sensing circuits to regulate both virulence and stress adaptation. Zoonotic Vibrio outbreaks are believed to be closely associated with increases in environmental temperature. The mechanisms underlying this phenomenon have not been defined. Here, we show that the expression of the V. alginolyticus exotoxin Asp and other quorum-sensing (QS)-regulated virulence factors are induced by increasing temperatures, with the maximum expression observed at approximately 37°C. σE plays an essential role in regulating the QS master regulator LuxR in response to temperature shifts by binding directly to the -10 and -35 regions of the luxR promoter to drive its transcription. However, at higher thermal stress temperatures, σE binding to the luxR promoter decreased, resulting in a reduction in luxR transcription. This change underlies a binomial switch mechanism that regulates σE-controlled virulence gene expression patterns. Furthermore, we found that anti-σE signaling was involved in this stress and virulence reciprocal switch. This study suggests that a common temperature response mechanism is integrated into QS circuits to regulate both virulence and adaptation in related Vibrio taxa.
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Affiliation(s)
- Dan Gu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Min Guo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Minjun Yang
- Shanghai—MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail: (XZ); (QW)
| | - Qiyao Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, Shanghai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
- * E-mail: (XZ); (QW)
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Zhao J, Yu X, Zhu M, Kang H, Ma J, Wu M, Gan J, Deng X, Liang H. Structural and Molecular Mechanism of CdpR Involved in Quorum-Sensing and Bacterial Virulence in Pseudomonas aeruginosa. PLoS Biol 2016; 14:e1002449. [PMID: 27119725 PMCID: PMC4847859 DOI: 10.1371/journal.pbio.1002449] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/24/2016] [Indexed: 01/07/2023] Open
Abstract
Although quorum-sensing (QS) systems are important regulators of virulence gene expression in the opportunistic human pathogen Pseudomonas aeruginosa, their detailed regulatory mechanisms have not been fully characterized. Here, we show that deletion of PA2588 resulted in increased production of pyocyanin and biofilm, as well as enhanced pathogenicity in a mouse model. To gain insights into the function of PA2588, we performed a ChIP-seq assay and identified 28 targets of PA2588, including the intergenic region between PA2588 and pqsH, which encodes the key synthase of Pseudomonas quinolone signal (PQS). Though the C-terminal domain was similar to DNA-binding regions of other AraC family members, structural studies revealed that PA2588 has a novel fold at the N-terminal region (NTR), and its C-terminal HTH (helix-turn-helix) domain is also unique in DNA recognition. We also demonstrated that the adaptor protein ClpS, an essential regulator of ATP-dependent protease ClpAP, directly interacted with PA2588 before delivering CdpR to ClpAP for degradation. We named PA2588 as CdpR (ClpAP-degradation and pathogenicity Regulator). Moreover, deletion of clpP or clpS/clpA promotes bacterial survival in a mouse model of acute pneumonia infection. Taken together, this study uncovered that CdpR is an important QS regulator, which can interact with the ClpAS-P system to regulate the expression of virulence factors and pathogenicity.
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Affiliation(s)
- Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Xiang Yu
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
- State Key Laboratory of Genetic Engineering, Innovative Collaborative Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Miao Zhu
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Huaping Kang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Innovative Collaborative Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Min Wu
- Department of Basic Science, School of Medicine and Health Science, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Jianhua Gan
- Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
- * E-mail: (JG); (XD); (HL)
| | - Xin Deng
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, China
- * E-mail: (JG); (XD); (HL)
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an, ShaanXi, China
- * E-mail: (JG); (XD); (HL)
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Vfr Directly Activates exsA Transcription To Regulate Expression of the Pseudomonas aeruginosa Type III Secretion System. J Bacteriol 2016; 198:1442-50. [PMID: 26929300 DOI: 10.1128/jb.00049-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/21/2016] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED The Pseudomonas aeruginosa cyclic AMP (cAMP)-Vfr system (CVS) is a global regulator of virulence gene expression. Regulatory targets include type IV pili, secreted proteases, and the type III secretion system (T3SS). The mechanism by which CVS regulates T3SS gene expression remains undefined. Single-cell expression studies previously found that only a portion of the cells within a population express the T3SS under inducing conditions, a property known as bistability. We now report that bistability is altered in avfr mutant, wherein a substantially smaller fraction of the cells express the T3SS relative to the parental strain. Since bistability usually involves positive-feedback loops, we tested the hypothesis that virulence factor regulator (Vfr) regulates the expression of exsA ExsA is the central regulator of T3SS gene expression and autoregulates its own expression. Although exsA is the last gene of the exsCEBA polycistronic mRNA, we demonstrate that Vfr directly activates exsA transcription from a second promoter (PexsA) located immediately upstream of exsA PexsA promoter activity is entirely Vfr dependent. Direct binding of Vfr to a PexsA promoter probe was demonstrated by electrophoretic mobility shift assays, and DNase I footprinting revealed an area of protection that coincides with a putative Vfr consensus-binding site. Mutagenesis of that site disrupted Vfr binding and PexsA promoter activity. We conclude that Vfr contributes to T3SS gene expression through activation of the PexsA promoter, which is internal to the previously characterized exsCEBA operon. IMPORTANCE Vfr is a cAMP-dependent DNA-binding protein that functions as a global regulator of virulence gene expression in Pseudomonas aeruginosa Regulation by Vfr allows for the coordinate production of related virulence functions, such as type IV pili and type III secretion, required for adherence to and intoxication of host cells, respectively. Although the molecular mechanism of Vfr regulation has been defined for many target genes, a direct link between Vfr and T3SS gene expression had not been established. In the present study, we report that Vfr directly controls exsA transcription, the master regulator of T3SS gene expression, from a newly identified promoter located immediately upstream of exsA.
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56
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Zhu M, Zhao J, Kang H, Kong W, Liang H. Modulation of Type III Secretion System in Pseudomonas aeruginosa: Involvement of the PA4857 Gene Product. Front Microbiol 2016; 7:7. [PMID: 26858696 PMCID: PMC4729953 DOI: 10.3389/fmicb.2016.00007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 01/06/2016] [Indexed: 11/21/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that causes serious acute or chronic infections in humans. Acute infections typically involve the type III secretion systems (T3SSs) and bacterial motility, whereas chronic infections are often associated with biofilm formation and the type VI secretion system. To identify new genes required for pathogenesis, a transposon mutagenesis library was constructed and the gene PA4857, named tspR, was found to modulate T3SS gene expression. Deletion of P. aeruginosa tspR reduced the virulence in a mouse acute lung infection model and diminished cytotoxicity. Suppression of T3SS gene expression in the tspR mutant resulted from compromised translation of the T3SS master regulator ExsA. TspR negatively regulated two small RNAs, RsmY and RsmZ, which control RsmA. Our data demonstrated that defects in T3SS expression and biofilm formation in retS mutant could be partially restored by overexpression of tspR. Taken together, our results demonstrated that the newly identified retS-tspR pathway is coordinated with the retS-gacS system, which regulates the genes associated with acute and chronic infections and controls the lifestyle choice of P. aeruginosa.
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Affiliation(s)
- Miao Zhu
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Department of Life Science, Northwest University Xi'an, China
| | - Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Department of Life Science, Northwest University Xi'an, China
| | - Huaping Kang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Department of Life Science, Northwest University Xi'an, China
| | - Weina Kong
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Department of Life Science, Northwest University Xi'an, China
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, Department of Life Science, Northwest University Xi'an, China
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57
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Li R, Tan S, Yu M, Jundt MC, Zhang S, Wu M. Annexin A2 Regulates Autophagy in Pseudomonas aeruginosa Infection through the Akt1-mTOR-ULK1/2 Signaling Pathway. THE JOURNAL OF IMMUNOLOGY 2015; 195:3901-11. [PMID: 26371245 DOI: 10.4049/jimmunol.1500967] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/06/2015] [Indexed: 02/05/2023]
Abstract
Earlier studies reported that a cell membrane protein, Annexin A2 (AnxA2), plays multiple roles in the development, invasion, and metastasis of cancer. Recent studies demonstrated that AnxA2 also functions in immunity against infection, but the underlying mechanism remains largely elusive. Using a mouse infection model, we reveal a crucial role for AnxA2 in host defense against Pseudomonas aeruginosa, as anxa2(-/-) mice manifested severe lung injury, systemic dissemination, and increased mortality compared with wild-type littermates. In addition, anxa2(-/-) mice exhibited elevated inflammatory cytokines (TNF-α, IL-6, IL-1β, and IFN-γ), decreased bacterial clearance by macrophages, and increased superoxide release in the lung. We further identified an unexpected molecular interaction between AnxA2 and Fam13A, which activated Rho GTPase. P. aeruginosa infection induced autophagosome formation by inhibiting Akt1 and mTOR. Our results indicate that AnxA2 regulates autophagy, thereby contributing to host immunity against bacteria through the Akt1-mTOR-ULK1/2 signaling pathway.
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Affiliation(s)
- Rongpeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 211800, People's Republic of China
| | - Shirui Tan
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; College of Agriculture, Yunnan University, Kunming 650091, People's Republic of China
| | - Min Yu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; Department of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China; and
| | - Michael C Jundt
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Shuang Zhang
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203;
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Kong W, Zhao J, Kang H, Zhu M, Zhou T, Deng X, Liang H. ChIP-seq reveals the global regulator AlgR mediating cyclic di-GMP synthesis in Pseudomonas aeruginosa. Nucleic Acids Res 2015. [PMID: 26206672 PMCID: PMC4787818 DOI: 10.1093/nar/gkv747] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
AlgR is a key transcriptional regulator required for the expression of multiple virulence factors, including type IV pili and alginate in Pseudomonas aeruginosa. However, the regulon and molecular regulatory mechanism of AlgR have yet to be fully elucidated. Here, among 157 loci that were identified by a ChIP-seq assay, we characterized a gene, mucR, which encodes an enzyme that synthesizes the intracellular second messenger cyclic diguanylate (c-di-GMP). A ΔalgR strain produced lesser biofilm than did the wild-type strain, which is consistent with a phenotype controlled by c-di-GMP. AlgR positively regulates mucR via direct binding to its promoter. A ΔalgRΔmucR double mutant produced lesser biofilm than did the single ΔalgR mutant, demonstrating that c-di-GMP is a positive regulator of biofilm formation. AlgR controls the levels of c-di-GMP synthesis via direct regulation of mucR. In addition, the cognate sensor of AlgR, FimS/AlgZ, also plays an important role in P. aeruginosa virulence. Taken together, this study provides new insights into the AlgR regulon and reveals the involvement of c-di-GMP in the mechanism underlying AlgR regulation.
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Affiliation(s)
- Weina Kong
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, China
| | - Jingru Zhao
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, China
| | - Huaping Kang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, China
| | - Miao Zhu
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, China
| | - Tianhong Zhou
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, Tianjin 300457, China
| | - Xin Deng
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, Tianjin 300457, China
| | - Haihua Liang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi'an, ShaanXi 710069, China
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Rahmani-Badi A, Sepehr S, Fallahi H, Heidari-Keshel S. Dissection of the cis-2-decenoic acid signaling network in Pseudomonas aeruginosa using microarray technique. Front Microbiol 2015; 7:383. [PMID: 25972860 PMCID: PMC4412052 DOI: 10.3389/fmicb.2015.00383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 03/10/2016] [Indexed: 11/29/2022] Open
Abstract
Many bacterial pathogens use quorum-sensing (QS) signaling to regulate the expression of factors contributing to virulence and persistence. Bacteria produce signals of different chemical classes. The signal molecule, known as diffusible signal factor (DSF), is a cis-unsaturated fatty acid that was first described in the plant pathogen Xanthomonas campestris. Previous works have shown that human pathogen, Pseudomonas aeruginosa, also synthesizes a structurally related molecule, characterized as cis-2-decenoic acid (C10: Δ2, CDA) that induces biofilm dispersal by multiple types of bacteria. Furthermore, CDA has been shown to be involved in inter-kingdom signaling that modulates fungal behavior. Therefore, an understanding of its signaling mechanism could suggest strategies for interference, with consequences for disease control. To identify the components of CDA signaling pathway in this pathogen, a comparative transcritpome analysis was conducted, in the presence and absence of CDA. A protein-protein interaction (PPI) network for differentially expressed (DE) genes with known function was then constructed by STRING and Cytoscape. In addition, the effects of CDA in combination with antimicrobial agents on the biofilm surface area and bacteria viability were evaluated using fluorescence microscopy and digital image analysis. Microarray analysis identified 666 differentially expressed genes in the presence of CDA and gene ontology (GO) analysis revealed that in P. aeruginosa, CDA mediates dispersion of biofilms through signaling pathways, including enhanced motility, metabolic activity, virulence as well as persistence at different temperatures. PPI data suggested that a cluster of five genes (PA4978, PA4979, PA4980, PA4982, PA4983) is involved in the CDA synthesis and perception. Combined treatments using both CDA and antimicrobial agents showed that following exposure of the biofilms to CDA, remaining cells on the surface were easily removed and killed by antimicrobials.
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Affiliation(s)
| | - Shayesteh Sepehr
- Department of Biology, School of Science, Alzahra University Tehran, Iran
| | - Hossein Fallahi
- Department of Biology, School of Science, Razi University Kermanshah, Iran
| | - Saeed Heidari-Keshel
- Stem Cell Preparation Unit, Eye Research Center, Farabi Eye Hospital Tehran, Iran
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