51
|
Cyclic di-AMP Acts as an Extracellular Signal That Impacts Bacillus subtilis Biofilm Formation and Plant Attachment. mBio 2018; 9:mBio.00341-18. [PMID: 29588402 PMCID: PMC5874923 DOI: 10.1128/mbio.00341-18] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
There is a growing appreciation for the impact that bacteria have on higher organisms. Plant roots often harbor beneficial microbes, such as the Gram-positive rhizobacterium Bacillus subtilis, that influence their growth and susceptibility to disease. The ability to form surface-attached microbial communities called biofilms is crucial for the ability of B. subtilis to adhere to and protect plant roots. In this study, strains harboring deletions of the B. subtilis genes known to synthesize and degrade the second messenger cyclic di-adenylate monophosphate (c-di-AMP) were examined for their involvement in biofilm formation and plant attachment. We found that intracellular production of c-di-AMP impacts colony biofilm architecture, biofilm gene expression, and plant attachment in B. subtilis. We also show that B. subtilis secretes c-di-AMP and that putative c-di-AMP transporters impact biofilm formation and plant root colonization. Taken together, our data describe a new role for c-di-AMP as a chemical signal that affects important cellular processes in the environmentally and agriculturally important soil bacterium B. subtilis. These results suggest that the “intracellular” signaling molecule c-di-AMP may also play a previously unappreciated role in interbacterial cell-cell communication within plant microbiomes. Plants harbor bacterial communities on their roots that can significantly impact their growth and pathogen resistance. In most cases, however, the signals that mediate host-microbe and microbe-microbe interactions within these communities are unknown. A detailed understanding of these interaction mechanisms could facilitate the manipulation of these communities for agricultural or environmental purposes. Bacillus subtilis is a plant-growth-promoting bacterium that adheres to roots by forming biofilms. We therefore began by exploring signals that might impact its biofilm formation. We found that B. subtilis secretes c-di-AMP and that the ability to produce, degrade, or transport cyclic di-adenylate monophosphate (c-di-AMP; a common bacterial second messenger) affects B. subtilis biofilm gene expression and plant attachment. To our knowledge, this is the first demonstration of c-di-AMP impacting a mutualist host-microbe association and suggests that c-di-AMP may function as a previously unappreciated extracellular signal able to mediate interactions within plant microbiomes.
Collapse
|
52
|
Deng YJ, Feng L, Zhou H, Xiao X, Wang FP, Liu XP. NanoRNase from Aeropyrum pernix shows nuclease activity on ssDNA and ssRNA. DNA Repair (Amst) 2018; 65:54-63. [PMID: 29609115 DOI: 10.1016/j.dnarep.2018.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/07/2018] [Accepted: 03/23/2018] [Indexed: 01/09/2023]
Abstract
In cells, degrading DNA and RNA by various nucleases is very important. These processes are strictly controlled and regulated to maintain DNA integrity and to mature or recycle various RNAs. NanoRNase (Nrn) is a 3'-exonuclease that specifically degrades nanoRNAs shorter than 5 nucleotides. Several Nrns have been identified and characterized in bacteria, mainly in Firmicutes. Archaea often grow in extreme environments and might be subjected to more damage to DNA/RNA, so DNA repair and recycling of damaged RNA are very important in archaea. There is no report on the identification and characterization of Nrn in archaea. Aeropyrum pernix encodes three potential Nrns: NrnA (Ape1437), NrnB (Ape0124), and an Nrn-like protein Ape2190. Biochemical characterization showed that only Ape0124 could degrade ssDNA and ssRNA from the 3'-end in the presence of Mn2+. Interestingly, unlike bacterial Nrns, Ape0124 prefers ssDNA, including short nanoDNA, and degrades nanoRNA with lower efficiency. The 3'-DNA backbone was found to be required for efficiently hydrolyzing the phosphodiester bonds. In addition, Ape0124 also degrads the 3'-overhang of double-stranded DNA. Interestingly, Ape0124 could hydrolyze pAp into AMP, which is a feature of bacterial NrnA, not NrnB. Our results indicate that Ape0124 is a novel Nrn with a combined substrate profile of bacterial NrnA and NrnB.
Collapse
Affiliation(s)
- Yong-Jie Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Lei Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Huan Zhou
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 239 Zhangheng Road, Shanghai 201204, China
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Feng-Ping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Xi-Peng Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
| |
Collapse
|
53
|
Regulation of the CRISPR-Associated Genes by Rv2837c (CnpB) via an Orn-Like Activity in Tuberculosis Complex Mycobacteria. J Bacteriol 2018; 200:JB.00743-17. [PMID: 29378893 DOI: 10.1128/jb.00743-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 01/25/2018] [Indexed: 12/14/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated proteins (Cas) provide bacteria and archaea with adaptive immunity to specific DNA invaders. Mycobacterium tuberculosis encodes a type III CRISPR-Cas system that has not been experimentally explored. In this study, we found that the CRISPR-Cas systems of both M. tuberculosis and Mycobacterium bovis BCG were highly upregulated by deletion of Rv2837c (cnpB), which encodes a multifunctional protein that hydrolyzes cyclic di-AMP (c-di-AMP), cyclic di-GMP (c-di-GMP), and nanoRNAs (short oligonucleotides of 5 or fewer residues). By using genetic and biochemical approaches, we demonstrated that the CnpB-controlled transcriptional regulation of the CRISPR-Cas system is mediated by an Orn-like activity rather than by hydrolyzing the cyclic dinucleotides. Additionally, our results revealed that tuberculosis (TB) complex mycobacteria are functional in processing CRISPR RNAs (crRNAs), which are also more abundant in the ΔcnpB strain than in the parent strain. The elevated crRNA levels in the ΔcnpB strain could be partially reduced by expressing Escherichia coli orn Our findings provide new insight into transcriptional regulation of bacterial CRISPR-Cas systems.IMPORTANCE Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated proteins (Cas) provide adaptive immunity to specific DNA invaders. M. tuberculosis encodes a type III CRISPR-Cas system that has not been experimentally explored. In this study, we first demonstrated that the CRISPR-Cas systems in tuberculosis (TB) complex mycobacteria are functional in processing CRISPR RNAs (crRNAs). We also showed that Rv2837c (CnpB) controls the expression of the CRISPR-Cas systems in TB complex mycobacteria through an oligoribonuclease (Orn)-like activity, which is very likely mediated by nanoRNA. Since little is known about regulation of CRISPR-Cas systems, our findings provide new insight into transcriptional regulation of bacterial CRISPR-Cas systems.
Collapse
|
54
|
Donovan ML, Schultz TE, Duke TJ, Blumenthal A. Type I Interferons in the Pathogenesis of Tuberculosis: Molecular Drivers and Immunological Consequences. Front Immunol 2017; 8:1633. [PMID: 29230217 PMCID: PMC5711827 DOI: 10.3389/fimmu.2017.01633] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/09/2017] [Indexed: 12/11/2022] Open
Abstract
Tuberculosis (TB) remains a major global health threat. Urgent needs in the fight against TB include improved and innovative treatment options for drug-sensitive and -resistant TB as well as reliable biological indicators that discriminate active from latent disease and enable monitoring of treatment success or failure. Prominent interferon (IFN) inducible gene signatures in TB patients and animal models of Mycobacterium tuberculosis infection have drawn significant attention to the roles of type I IFNs in the host response to mycobacterial infections. Here, we review recent developments in the understanding of the innate immune pathways that drive type I IFN responses in mycobacteria-infected host cells and the functional consequences for the host defense against M. tuberculosis, with a view that such insights might be exploited for the development of targeted host-directed immunotherapies and development of reliable biomarkers.
Collapse
Affiliation(s)
- Meg L Donovan
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Thomas E Schultz
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Taylor J Duke
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| | - Antje Blumenthal
- The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia
| |
Collapse
|
55
|
Devaux L, Kaminski PA, Trieu-Cuot P, Firon A. Cyclic di-AMP in host-pathogen interactions. Curr Opin Microbiol 2017; 41:21-28. [PMID: 29169058 DOI: 10.1016/j.mib.2017.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/24/2017] [Accepted: 11/04/2017] [Indexed: 01/09/2023]
Abstract
Cyclic di-AMP (c-di-AMP) is a bacterial signaling nucleotide synthesized by several human pathogens. This widespread and specific bacterial product is recognized by infected host cells to trigger an innate immune response. Detection of c-di-AMP in the host cytosol leads primarily to the induction of type I interferon via the STING-cGAS signaling axis, while being also entangled in the activation of the NF-κB pathway. During their long-standing interaction, host and pathogens have co-evolved to control c-di-AMP activation of innate immunity. On the bacterial side, the quantity of c-di-AMP released inside cells allows to manipulate the host response to exacerbate infection by avoiding immune recognition or, at the opposite, by overloading the STING-cGAS pathway.
Collapse
Affiliation(s)
- Laura Devaux
- Institut Pasteur, Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS URL3526, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Pierre-Alexandre Kaminski
- Institut Pasteur, Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS URL3526, Paris, France
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS URL3526, Paris, France
| | - Arnaud Firon
- Institut Pasteur, Unité Biologie des Bactéries Pathogènes à Gram-positif, CNRS URL3526, Paris, France.
| |
Collapse
|
56
|
Sensing of Bacterial Cyclic Dinucleotides by the Oxidoreductase RECON Promotes NF-κB Activation and Shapes a Proinflammatory Antibacterial State. Immunity 2017; 46:433-445. [PMID: 28329705 DOI: 10.1016/j.immuni.2017.02.014] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/20/2016] [Accepted: 01/13/2017] [Indexed: 12/25/2022]
Abstract
Bacterial and host cyclic dinucleotides (cdNs) mediate cytosolic immune responses through the STING signaling pathway, although evidence suggests that alternative pathways exist. We used cdN-conjugated beads to biochemically isolate host receptors for bacterial cdNs, and we identified the oxidoreductase RECON. High-affinity cdN binding inhibited RECON enzyme activity by simultaneously blocking the substrate and cosubstrate sites, as revealed by structural analyses. During bacterial infection of macrophages, RECON antagonized STING activation by acting as a molecular sink for cdNs. Bacterial infection of hepatocytes, which do not express STING, revealed that RECON negatively regulates NF-κB activation. Loss of RECON activity, via genetic ablation or inhibition by cdNs, increased NF-κB activation and reduced bacterial survival, suggesting that cdN inhibition of RECON promotes a proinflammatory, antibacterial state that is distinct from the antiviral state associated with STING activation. Thus, RECON functions as a cytosolic sensor for bacterial cdNs, shaping inflammatory gene activation via its effects on STING and NF-κB.
Collapse
|
57
|
Choi PH, Vu TMN, Pham HT, Woodward JJ, Turner MS, Tong L. Structural and functional studies of pyruvate carboxylase regulation by cyclic di-AMP in lactic acid bacteria. Proc Natl Acad Sci U S A 2017; 114:E7226-E7235. [PMID: 28808024 PMCID: PMC5584425 DOI: 10.1073/pnas.1704756114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cyclic di-3',5'-adenosine monophosphate (c-di-AMP) is a broadly conserved bacterial second messenger that has been implicated in a wide range of cellular processes. Our earlier studies showed that c-di-AMP regulates central metabolism in Listeria monocytogenes by inhibiting its pyruvate carboxylase (LmPC), a biotin-dependent enzyme with biotin carboxylase (BC) and carboxyltransferase (CT) activities. We report here structural, biochemical, and functional studies on the inhibition of Lactococcus lactis PC (LlPC) by c-di-AMP. The compound is bound at the dimer interface of the CT domain, at a site equivalent to that in LmPC, although it has a distinct binding mode in the LlPC complex. This binding site is not well conserved among PCs, and only a subset of these bacterial enzymes are sensitive to c-di-AMP. Conformational changes in the CT dimer induced by c-di-AMP binding may be the molecular mechanism for its inhibitory activity. Mutations of residues in the binding site can abolish c-di-AMP inhibition. In L. lactis, LlPC is required for efficient milk acidification through its essential role in aspartate biosynthesis. The aspartate pool in L. lactis is negatively regulated by c-di-AMP, and high aspartate levels can be restored by expression of a c-di-AMP-insensitive LlPC. LlPC has high intrinsic catalytic activity and is not sensitive to acetyl-CoA activation, in contrast to other PC enzymes.
Collapse
Affiliation(s)
- Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Thu Minh Ngoc Vu
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Huong Thi Pham
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Mark S Turner
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027;
| |
Collapse
|
58
|
Valadares NF, Woo J. Mechanism of Rv2837c from Mycobacterium tuberculosis remains controversial. J Biol Chem 2017; 292:13480. [PMID: 28801352 DOI: 10.1074/jbc.l116.760678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Napoleão Fonseca Valadares
- From the Laboratory of Molecular Biophysics, Department of Cell Biology, University of Brasília, Brasília -DF, 70910-900, Brazil and
| | - James Woo
- the Department of Biochemistry and Molecular Biology, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064
| |
Collapse
|
59
|
Fahmi T, Port GC, Cho KH. c-di-AMP: An Essential Molecule in the Signaling Pathways that Regulate the Viability and Virulence of Gram-Positive Bacteria. Genes (Basel) 2017; 8:E197. [PMID: 28783096 PMCID: PMC5575661 DOI: 10.3390/genes8080197] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 11/16/2022] Open
Abstract
Signal transduction pathways enable organisms to monitor their external environment and adjust gene regulation to appropriately modify their cellular processes. Second messenger nucleotides including cyclic adenosine monophosphate (c-AMP), cyclic guanosine monophosphate (c-GMP), cyclic di-guanosine monophosphate (c-di-GMP), and cyclic di-adenosine monophosphate (c-di-AMP) play key roles in many signal transduction pathways used by prokaryotes and/or eukaryotes. Among the various second messenger nucleotides molecules, c-di-AMP was discovered recently and has since been shown to be involved in cell growth, survival, and regulation of virulence, primarily within Gram-positive bacteria. The cellular level of c-di-AMP is maintained by a family of c-di-AMP synthesizing enzymes, diadenylate cyclases (DACs), and degradation enzymes, phosphodiesterases (PDEs). Genetic manipulation of DACs and PDEs have demonstrated that alteration of c-di-AMP levels impacts both growth and virulence of microorganisms. Unlike other second messenger molecules, c-di-AMP is essential for growth in several bacterial species as many basic cellular functions are regulated by c-di-AMP including cell wall maintenance, potassium ion homeostasis, DNA damage repair, etc. c-di-AMP follows a typical second messenger signaling pathway, beginning with binding to receptor molecules to subsequent regulation of downstream cellular processes. While c-di-AMP binds to specific proteins that regulate pathways in bacterial cells, c-di-AMP also binds to regulatory RNA molecules that control potassium ion channel expression in Bacillus subtilis. c-di-AMP signaling also occurs in eukaryotes, as bacterially produced c-di-AMP stimulates host immune responses during infection through binding of innate immune surveillance proteins. Due to its existence in diverse microorganisms, its involvement in crucial cellular activities, and its stimulating activity in host immune responses, c-di-AMP signaling pathway has become an attractive antimicrobial drug target and therefore has been the focus of intensive study in several important pathogens.
Collapse
Affiliation(s)
- Tazin Fahmi
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA.
| | - Gary C Port
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
- Elanco Animal Health, Natural Products Fermentation, Eli Lilly and Company, Indianapolis, IN 46285, USA.
| | - Kyu Hong Cho
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA.
| |
Collapse
|
60
|
Li Y, Wilson HL, Kiss-Toth E. Regulating STING in health and disease. J Inflamm (Lond) 2017; 14:11. [PMID: 28596706 PMCID: PMC5463399 DOI: 10.1186/s12950-017-0159-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/26/2017] [Indexed: 12/15/2022] Open
Abstract
The presence of cytosolic double-stranded DNA molecules can trigger multiple innate immune signalling pathways which converge on the activation of an ER-resident innate immune adaptor named "STimulator of INterferon Genes (STING)". STING has been found to mediate type I interferon response downstream of cyclic dinucleotides and a number of DNA and RNA inducing signalling pathway. In addition to its physiological function, a rapidly increasing body of literature highlights the role for STING in human disease where variants of the STING proteins, as well as dysregulated STING signalling, have been implicated in a number of inflammatory diseases. This review will summarise the recent structural and functional findings of STING, and discuss how STING research has promoted the development of novel therapeutic approaches and experimental tools to improve treatment of tumour and autoimmune diseases.
Collapse
Affiliation(s)
- Yang Li
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
| | - Heather L. Wilson
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
| | - Endre Kiss-Toth
- Department of Infection; Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX UK
| |
Collapse
|
61
|
Whiteley AT, Garelis NE, Peterson BN, Choi PH, Tong L, Woodward JJ, Portnoy DA. c-di-AMP modulates Listeria monocytogenes central metabolism to regulate growth, antibiotic resistance and osmoregulation. Mol Microbiol 2017; 104:212-233. [PMID: 28097715 DOI: 10.1111/mmi.13622] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2017] [Indexed: 12/26/2022]
Abstract
Cyclic diadenosine monophosphate (c-di-AMP) is a conserved nucleotide second messenger critical for bacterial growth and resistance to cell wall-active antibiotics. In Listeria monocytogenes, the sole diadenylate cyclase, DacA, is essential in rich, but not synthetic media and ΔdacA mutants are highly sensitive to the β-lactam antibiotic cefuroxime. In this study, loss of function mutations in the oligopeptide importer (oppABCDF) and glycine betaine importer (gbuABC) allowed ΔdacA mutants to grow in rich medium. Since oligopeptides were sufficient to inhibit growth of the ΔdacA mutant we hypothesized that oligopeptides act as osmolytes, similar to glycine betaine, to disrupt intracellular osmotic pressure. Supplementation with salt stabilized the ΔdacA mutant in rich medium and restored cefuroxime resistance. Additional suppressor mutations in the acetyl-CoA binding site of pyruvate carboxylase (PycA) rescued cefuroxime resistance and resulted in a 100-fold increase in virulence of the ΔdacA mutant. PycA is inhibited by c-di-AMP and these mutations prompted us to examine the role of TCA cycle enzymes. Inactivation of citrate synthase, but not down-stream enzymes suppressed ΔdacA phenotypes. These data suggested that c-di-AMP modulates central metabolism at the pyruvate node to moderate citrate production and indeed, the ΔdacA mutant accumulated six times the concentration of citrate present in wild-type bacteria.
Collapse
Affiliation(s)
- Aaron T Whiteley
- Graduate Group in Infectious Diseases and Immunity, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Nicholas E Garelis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Bret N Peterson
- Graduate Group in Microbiology, University of California, Berkeley, Berkeley, CA, USA
| | - Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Daniel A Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.,School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
62
|
Bowman L, Zeden MS, Schuster CF, Kaever V, Gründling A. New Insights into the Cyclic Di-adenosine Monophosphate (c-di-AMP) Degradation Pathway and the Requirement of the Cyclic Dinucleotide for Acid Stress Resistance in Staphylococcus aureus. J Biol Chem 2016; 291:26970-26986. [PMID: 27834680 PMCID: PMC5207132 DOI: 10.1074/jbc.m116.747709] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/09/2016] [Indexed: 12/02/2022] Open
Abstract
Nucleotide signaling networks are key to facilitate alterations in gene expression, protein function, and enzyme activity in response to diverse stimuli. Cyclic di-adenosine monophosphate (c-di-AMP) is an important secondary messenger molecule produced by the human pathogen Staphylococcus aureus and is involved in regulating a number of physiological processes including potassium transport. S. aureus must ensure tight control over its cellular levels as both high levels of the dinucleotide and its absence result in a number of detrimental phenotypes. Here we show that in addition to the membrane-bound Asp-His-His and Asp-His-His-associated (DHH/DHHA1) domain-containing phosphodiesterase (PDE) GdpP, S. aureus produces a second cytoplasmic DHH/DHHA1 PDE Pde2. Although capable of hydrolyzing c-di-AMP, Pde2 preferentially converts linear 5'-phosphadenylyl-adenosine (pApA) to AMP. Using a pde2 mutant strain, pApA was detected for the first time in S. aureus, leading us to speculate that this dinucleotide may have a regulatory role under certain conditions. Moreover, pApA is involved in a feedback inhibition loop that limits GdpP-dependent c-di-AMP hydrolysis. Another protein linked to the regulation of c-di-AMP levels in bacteria is the predicted regulator protein YbbR. Here, it is shown that a ybbR mutant S. aureus strain has increased acid sensitivity that can be bypassed by the acquisition of mutations in a number of genes, including the gene coding for the diadenylate cyclase DacA. We further show that c-di-AMP levels are slightly elevated in the ybbR suppressor strains tested as compared with the wild-type strain. With this, we not only identified a new role for YbbR in acid stress resistance in S. aureus but also provide further insight into how c-di-AMP levels impact acid tolerance in this organism.
Collapse
Affiliation(s)
- Lisa Bowman
- From the Section of Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom and
| | - Merve S Zeden
- From the Section of Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom and
| | - Christopher F Schuster
- From the Section of Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom and
| | - Volkhard Kaever
- the Research Core Unit Metabolomics, Hannover Medical School, Hannover D-306625, Germany
| | - Angelika Gründling
- From the Section of Microbiology and Medical Research Council Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, United Kingdom and
| |
Collapse
|
63
|
Inhibition of innate immune cytosolic surveillance by an M. tuberculosis phosphodiesterase. Nat Chem Biol 2016; 13:210-217. [PMID: 28106876 DOI: 10.1038/nchembio.2254] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/05/2016] [Indexed: 12/18/2022]
Abstract
Mycobacterium tuberculosis infection leads to cytosolic release of the bacterial cyclic dinucleotide (CDN) c-di-AMP and a host-generated CDN, cGAMP, both of which trigger type I interferon (IFN) expression in a STING-dependent manner. Here we report that M. tuberculosis has developed a mechanism to inhibit STING activation and the type I IFN response via the bacterial phosphodiesterase (PDE) CdnP, which mediates hydrolysis of both bacterial-derived c-di-AMP and host-derived cGAMP. Mutation of cdnP attenuates M. tuberculosis virulence, as does loss of a host CDN PDE known as ENPP1. CdnP is inhibited by both US Food and Drug Administration (FDA)-approved PDE inhibitors and nonhydrolyzable dinucleotide mimetics specifically designed to target the enzyme. These findings reveal a crucial role of CDN homeostasis in governing the outcome of M. tuberculosis infection as well as a unique mechanism of subversion of the host's cytosolic surveillance pathway (CSP) by a bacterial PDE that may serve as an attractive antimicrobial target.
Collapse
|
64
|
Huynh TN, Choi PH, Sureka K, Ledvina HE, Campillo J, Tong L, Woodward JJ. Cyclic di-AMP targets the cystathionine beta-synthase domain of the osmolyte transporter OpuC. Mol Microbiol 2016; 102:233-243. [PMID: 27378384 DOI: 10.1111/mmi.13456] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2016] [Indexed: 12/26/2022]
Abstract
Cellular turgor is of fundamental importance to bacterial growth and survival. Changes in external osmolarity as a consequence of fluctuating environmental conditions and colonization of diverse environments can significantly impact cytoplasmic water content, resulting in cellular lysis or plasmolysis. To ensure maintenance of appropriate cellular turgor, bacteria import ions and small organic osmolytes, deemed compatible solutes, to equilibrate cytoplasmic osmolarity with the extracellular environment. Here, we show that elevated levels of c-di-AMP, a ubiquitous second messenger among bacteria, result in significant susceptibility to elevated osmotic stress in the bacterial pathogen Listeria monocytogenes. We found that levels of import of the compatible solute carnitine show an inverse correlation with intracellular c-di-AMP content and that c-di-AMP directly binds to the CBS domain of the ATPase subunit of the carnitine importer OpuC. Biochemical and structural studies identify conserved residues required for this interaction and transport activity in bacterial cells. Overall, these studies reveal a role for c-di-AMP mediated regulation of compatible solute import and provide new insight into the molecular mechanisms by which this essential second messenger impacts bacterial physiology and adaptation to changing environmental conditions.
Collapse
Affiliation(s)
- TuAnh Ngoc Huynh
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
| | - Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Kamakshi Sureka
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
| | - Hannah E Ledvina
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
| | - Julian Campillo
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA, 98195, USA.
| |
Collapse
|
65
|
Opoku-Temeng C, Zhou J, Zheng Y, Su J, Sintim HO. Cyclic dinucleotide (c-di-GMP, c-di-AMP, and cGAMP) signalings have come of age to be inhibited by small molecules. Chem Commun (Camb) 2016; 52:9327-42. [PMID: 27339003 DOI: 10.1039/c6cc03439j] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacteria utilize nucleotide-based second messengers to regulate a myriad of physiological processes. Cyclic dinucleotides have emerged as central regulators of bacterial physiology, controlling processes ranging from cell wall homeostasis to virulence production, and so far over thousands of manuscripts have provided biological insights into c-di-NMP signaling. The development of small molecule inhibitors of c-di-NMP signaling has significantly lagged behind. Recent developments in assays that allow for high-throughput screening of inhibitors suggest that the time is right for a concerted effort to identify inhibitors of these fascinating second messengers. Herein, we review c-di-NMP signaling and small molecules that have been developed to inhibit cyclic dinucleotide-related enzymes.
Collapse
Affiliation(s)
- Clement Opoku-Temeng
- Department of Chemistry, Center for Drug Discovery, Purdue University, West Lafayette, IN 47907, USA.
| | | | | | | | | |
Collapse
|
66
|
López-Villamizar I, Cabezas A, Pinto RM, Canales J, Ribeiro JM, Cameselle JC, Costas MJ. The Characterization of Escherichia coli CpdB as a Recombinant Protein Reveals that, besides Having the Expected 3´-Nucleotidase and 2´,3´-Cyclic Mononucleotide Phosphodiesterase Activities, It Is Also Active as Cyclic Dinucleotide Phosphodiesterase. PLoS One 2016; 11:e0157308. [PMID: 27294396 PMCID: PMC4905662 DOI: 10.1371/journal.pone.0157308] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/30/2016] [Indexed: 02/06/2023] Open
Abstract
Endogenous cyclic diadenylate phosphodiesterase activity was accidentally detected in lysates of Escherichia coli BL21. Since this kind of activity is uncommon in Gram-negative bacteria, its identification was undertaken. After partial purification and analysis by denaturing gel electrophoresis, renatured activity correlated with a protein identified by fingerprinting as CpdB (cpdB gene product), which is annotated as 3´-nucleotidase / 2´,3´-cyclic-mononucleotide phosphodiesterase, and it is synthesized as a precursor protein with a signal sequence removable upon export to the periplasm. It has never been studied as a recombinant protein. The coding sequence of mature CpdB was cloned and expressed as a GST fusion protein. The study of the purified recombinant protein, separated from GST, confirmed CpdB annotation. The assay of catalytic efficiencies (kcat/Km) for a large substrate set revealed novel CpdB features, including very high efficiencies for 3´-AMP and 2´,3´-cyclic mononucleotides, and previously unknown activities on cyclic and linear dinucleotides. The catalytic efficiencies of the latter activities, though low in relative terms when compared to the major ones, are far from negligible. Actually, they are perfectly comparable to those of the ‘average’ enzyme and the known, bona fide cyclic dinucleotide phosphodiesterases. On the other hand, CpdB differs from these enzymes in its extracytoplasmic location and in the absence of EAL, HD and DHH domains. Instead, it contains the domains of the 5´-nucleotidase family pertaining to the metallophosphoesterase superfamily, although CpdB lacks 5´-nucleotidase activity. The possibility that the extracytoplasmic activity of CpdB on cyclic dinucleotides could have physiological meaning is discussed.
Collapse
Affiliation(s)
- Iralis López-Villamizar
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - Alicia Cabezas
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - Rosa María Pinto
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - José Canales
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - João Meireles Ribeiro
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - José Carlos Cameselle
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
| | - María Jesús Costas
- Grupo de Enzimología, Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
- * E-mail:
| |
Collapse
|
67
|
Olive AJ, Sassetti CM. Metabolic crosstalk between host and pathogen: sensing, adapting and competing. Nat Rev Microbiol 2016; 14:221-34. [PMID: 26949049 DOI: 10.1038/nrmicro.2016.12] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Our understanding of bacterial pathogenesis is dominated by the cell biology of the host-pathogen interaction. However, the majority of metabolites that are used in prokaryotic and eukaryotic physiology and signalling are chemically similar or identical. Therefore, the metabolic crosstalk between pathogens and host cells may be as important as the interactions between bacterial effector proteins and their host targets. In this Review we focus on host-pathogen interactions at the metabolic level: chemical signalling events that enable pathogens to sense anatomical location and the local physiology of the host; microbial metabolic pathways that are dedicated to circumvent host immune mechanisms; and a few metabolites as central points of competition between the host and bacterial pathogens.
Collapse
Affiliation(s)
- Andrew J Olive
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| |
Collapse
|
68
|
Peng X, Zhang Y, Bai G, Zhou X, Wu H. Cyclic di-AMP mediates biofilm formation. Mol Microbiol 2016; 99:945-59. [PMID: 26564551 PMCID: PMC5003771 DOI: 10.1111/mmi.13277] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2015] [Indexed: 12/27/2022]
Abstract
Cyclic di-AMP (c-di-AMP) is an emerging second messenger in bacteria. It has been shown to play important roles in bacterial fitness and virulence. However, transduction of c-di-AMP signaling in bacteria and the role of c-di-AMP in biofilm formation are not well understood. The level of c-di-AMP is modulated by activity of di-adenylyl cyclase that produces c-di-AMP and phosphodiesterase (PDE) that degrades c-di-AMP. In this study, we determined that increased c-di-AMP levels by deletion of the pdeA gene coding for a PDE promoted biofilm formation in Streptococcus mutans. Deletion of pdeA upregulated expression of gtfB, the gene coding for a major glucan producing enzyme. Inactivation of gtfB blocked the increased biofilm by the pdeA mutant. Two c-di-AMP binding proteins including CabPA (SMU_1562) and CabPB (SMU_1708) were identified. Interestingly, only CabPA deficiency inhibited both the increased biofilm formation and the upregulated expression of GtfB observed in the pdeA mutant. In addition, CabPA but not CabPB interacted with VicR, a known transcriptional factor that regulates expression of gtfB, suggesting that a signaling link between CabPA and GtfB through VicR. Increased biofilm by the pdeA deficiency also enhanced bacterial colonization of Drosophila in vivo. Taken together, our studies reveal a new role of c-di-AMP in mediating biofilm formation through a CabPA/VicR/GtfB signaling network in S. mutans.
Collapse
Affiliation(s)
- Xian Peng
- Department of Pediatric Dentistry, University of Alabama at Birmingham, School of Dentistry, Birmingham, AL, USA
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China
| | - Yang Zhang
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, 47 New Scotland Avenue, Albany, NY, USA
| | - Guangchun Bai
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, 47 New Scotland Avenue, Albany, NY, USA
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China
| | - Hui Wu
- Department of Pediatric Dentistry, University of Alabama at Birmingham, School of Dentistry, Birmingham, AL, USA
| |
Collapse
|
69
|
Malhotra N, Chakraborti PK. Eukaryotic-Type Ser/Thr Protein Kinase Mediated Phosphorylation of Mycobacterial Phosphodiesterase Affects its Localization to the Cell Wall. Front Microbiol 2016; 7:123. [PMID: 26904001 PMCID: PMC4746578 DOI: 10.3389/fmicb.2016.00123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 01/22/2016] [Indexed: 11/13/2022] Open
Abstract
Phosphodiesterase enzymes, involved in cAMP hydrolysis reaction, are present throughout phylogeny and their phosphorylation mediated regulation remains elusive in prokaryotes. In this context, we focused on this enzyme from Mycobacterium tuberculosis. The gene encoded by Rv0805 was PCR amplified and expressed as a histidine-tagged protein (mPDE) utilizing Escherichia coli based expression system. In kinase assays, upon incubation with mycobacterial Clade I eukaryotic-type Ser/Thr kinases (PknA, PknB, and PknL), Ni-NTA purified mPDE protein exhibited transphosphorylation ability albeit with varying degree. When mPDE was co-expressed one at a time with these kinases in E. coli, it was also recognized by an anti-phosphothreonine antibody, which further indicates its phosphorylating ability. Mass spectrometric analysis identified Thr-309 of mPDE as a phosphosite. In concordance with this observation, anti-phosphothreonine antibody marginally recognized mPDE-T309A mutant protein; however, such alteration did not affect the enzymatic activity. Interestingly, mPDE expressed in Mycobacterium smegmatis yielded a phosphorylated protein that preferentially localized to cell wall. In contrast, mPDE-T309A, the phosphoablative variant of mPDE, did not show such behavior. On the other hand, phosphomimics of mPDE (T309D or T309E), exhibited similar cell wall anchorage as was observed with the wild-type. Thus, our results provide credence to the fact that eukaryotic-type Ser/Thr kinase mediated phosphorylation of mPDE renders negative charge to the protein, promoting its localization on cell wall. Furthermore, multiple sequence alignment revealed that Thr-309 is conserved among mPDE orthologs of M. tuberculosis complex, which presumably emphasizes evolutionary significance of phosphorylation at this residue.
Collapse
Affiliation(s)
- Neha Malhotra
- CSIR-Institute of Microbial Technology Chandigarh, India
| | | |
Collapse
|
70
|
Huynh TN, Woodward JJ. Too much of a good thing: regulated depletion of c-di-AMP in the bacterial cytoplasm. Curr Opin Microbiol 2016; 30:22-29. [PMID: 26773214 DOI: 10.1016/j.mib.2015.12.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 01/11/2023]
Abstract
Bacteria that synthesize c-di-AMP also encode several mechanisms for controlling c-di-AMP levels within the cytoplasm. One major class of phosphodiesterases comprises GdpP and DhhP homologs, which degrade c-di-AMP into the linear molecule 5'-pApA or AMP by the DHH-DHHA1 domain. The other major class comprises PgpH homologs, which degrade c-di-AMP by the HD domain. Both GdpP and PgpH harbor sensory domains, likely to regulate c-di-AMP hydrolysis activity in response to signal input. As another possible mechanism for controlling cytoplasmic c-di-AMP levels, bacteria also secrete c-di-AMP via multidrug resistance transporters, as demonstrated for Listeria monocytogenes. Mutants that accumulate high c-di-AMP levels, by deletion of phosphodiesterases or multidrug resistance transporters, exhibit aberrant physiology, growth defects, and attenuated virulence in infection.
Collapse
Affiliation(s)
- TuAnh Ngoc Huynh
- Department of Microbiology, University of Washington, Seattle, WA, United States
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA, United States.
| |
Collapse
|
71
|
He Q, Wang F, Liu S, Zhu D, Cong H, Gao F, Li B, Wang H, Lin Z, Liao J, Gu L. Structural and Biochemical Insight into the Mechanism of Rv2837c from Mycobacterium tuberculosis as a c-di-NMP Phosphodiesterase. J Biol Chem 2015; 291:3668-81. [PMID: 26668313 DOI: 10.1074/jbc.m115.699801] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Indexed: 12/18/2022] Open
Abstract
The intracellular infections of Mycobacterium tuberculosis, which is the causative agent of tuberculosis, are regulated by many cyclic dinucleotide signaling. Rv2837c from M. tuberculosis is a soluble, stand-alone DHH-DHHA1 domain phosphodiesterase that down-regulates c-di-AMP through catalytic degradation and plays an important role in M. tuberculosis infections. Here, we report the crystal structure of Rv2837c (2.0 Å), and its complex with hydrolysis intermediate 5'-pApA (2.35 Å). Our structures indicate that both DHH and DHHA1 domains are essential for c-di-AMP degradation. Further structural analysis shows that Rv2837c does not distinguish adenine from guanine, which explains why Rv2837c hydrolyzes all linear dinucleotides with almost the same efficiency. We observed that Rv2837c degraded other c-di-NMPs at a lower rate than it did on c-di-AMP. Nevertheless, our data also showed that Rv2837c significantly decreases concentrations of both c-di-AMP and c-di-GMP in vivo. Our results suggest that beside its major role in c-di-AMP degradation Rv2837c could also regulate c-di-GMP signaling pathways in bacterial cell.
Collapse
Affiliation(s)
- Qing He
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Feng Wang
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Shiheng Liu
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Deyu Zhu
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Hengjiang Cong
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Fei Gao
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Bingqing Li
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Hongwei Wang
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China
| | - Zong Lin
- the Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Jiaxing, Zhejiang 314006, China, and
| | - Jun Liao
- the School of Life Science and Technology, ShanghaiTech University, Shanghai 200031, China
| | - Lichuan Gu
- From the State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, Shandong, 250100, China,
| |
Collapse
|
72
|
Cheng X, Zheng X, Zhou X, Zeng J, Ren Z, Xu X, Cheng L, Li M, Li J, Li Y. Regulation of oxidative response and extracellular polysaccharide synthesis by a diadenylate cyclase in Streptococcus mutans. Environ Microbiol 2015; 18:904-22. [PMID: 26548332 DOI: 10.1111/1462-2920.13123] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/29/2015] [Accepted: 11/01/2015] [Indexed: 02/05/2023]
Abstract
Cyclic diadenosine monophosphate (c-di-AMP) has been implicated in the control of many important bacterial activities. However, the function of this molecule in Streptococcus mutans, the primary aetiological agent of human dental caries, is unknown. In this study, we identified and characterized a diadenylate cyclase, named CdaA, in S. mutans. Furthermore, we showed that in-frame deletion of the cdaA gene in S. mutans causes decreased c-di-AMP levels, increased sensitivity to hydrogen peroxide and increased production of extracellular polysaccharides. Global gene expression profiling revealed that more than 200 genes were significantly upregulated or downregulated (> 2.0-fold) in the cdaA mutant. Interestingly, genes with increased or decreased expression were clustered in cellular polysaccharide biosynthetic processes and oxidoreductase activity respectively. Notably, the expression of several genomic islands, such as GTF-B/C, TnSmu, CRISPR1-Cas and CRISPR2-Cas, was found to be altered in the cdaA mutant, indicating a possible link between these genomic islands and c-di-AMP signalling. Collectively, the results reported here show that CdaA is an important global modulator in S. mutans and is required for optimal growth and environmental adaption. This report also paves the way to unveil further the roles of c-di-AMP signalling networks in the biology and pathogenicity of S. mutans.
Collapse
Affiliation(s)
- Xingqun Cheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xin Zheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jumei Zeng
- Department of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Zhi Ren
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xin Xu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Mingyun Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jiyao Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| |
Collapse
|
73
|
Stamm CE, Collins AC, Shiloh MU. Sensing of Mycobacterium tuberculosis and consequences to both host and bacillus. Immunol Rev 2015; 264:204-19. [PMID: 25703561 DOI: 10.1111/imr.12263] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mycobacterium tuberculosis (Mtb), the primary causative agent of human tuberculosis, has killed more people than any other bacterial pathogen in human history and remains one of the most important transmissible diseases worldwide. Because of the long-standing interaction of Mtb with humans, it is no surprise that human mucosal and innate immune cells have evolved multiple mechanisms to detect Mtb during initial contact. To that end, the cell surface of human cells is decorated with numerous pattern recognition receptors for a variety of mycobacterial ligands. Furthermore, once Mtb is ingested into professional phagocytes, other host molecules are engaged to report on the presence of an intracellular pathogen. In this review, we discuss the role of specific mycobacterial products in modulating the host's ability to detect Mtb. In addition, we describe the specific host receptors that mediate the detection of mycobacterial infection and the role of individual receptors in mycobacterial pathogenesis in humans and model organisms.
Collapse
Affiliation(s)
- Chelsea E Stamm
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | | |
Collapse
|
74
|
Ranganathan S, Bai G, Lyubetskaya A, Knapp GS, Peterson MW, Gazdik M, C Gomes AL, Galagan JE, McDonough KA. Characterization of a cAMP responsive transcription factor, Cmr (Rv1675c), in TB complex mycobacteria reveals overlap with the DosR (DevR) dormancy regulon. Nucleic Acids Res 2015; 44:134-51. [PMID: 26358810 PMCID: PMC4705688 DOI: 10.1093/nar/gkv889] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/26/2015] [Indexed: 12/17/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) Cmr (Rv1675c) is a CRP/FNR family transcription factor known to be responsive to cAMP levels and during macrophage infections. However, Cmr's DNA binding properties, cellular targets and overall role in tuberculosis (TB) complex bacteria have not been characterized. In this study, we used experimental and computational approaches to characterize Cmr's DNA binding properties and identify a putative regulon. Cmr binds a 16-bp palindromic site that includes four highly conserved nucleotides that are required for DNA binding. A total of 368 binding sites, distributed in clusters among ∼200 binding regions throughout the Mycobacterium bovis BCG genome, were identified using ChIP-seq. One of the most enriched Cmr binding sites was located upstream of the cmr promoter, and we demonstrated that expression of cmr is autoregulated. cAMP affected Cmr binding at a subset of DNA loci in vivo and in vitro, including multiple sites adjacent to members of the DosR (DevR) dormancy regulon. Our findings of cooperative binding of Cmr to these DNA regions and the regulation by Cmr of the DosR-regulated virulence gene Rv2623 demonstrate the complexity of Cmr-mediated gene regulation and suggest a role for Cmr in the biology of persistent TB infection.
Collapse
Affiliation(s)
- Sridevi Ranganathan
- Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, Albany, NY 12201, USA
| | - Guangchun Bai
- Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, PO Box 22002, Albany, NY 12201-2002, USA
| | - Anna Lyubetskaya
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Gwendowlyn S Knapp
- Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, PO Box 22002, Albany, NY 12201-2002, USA
| | | | - Michaela Gazdik
- Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, Albany, NY 12201, USA
| | | | - James E Galagan
- Bioinformatics Program, Boston University, Boston, MA 02215, USA Department of Microbiology, Boston University, Boston, MA 02215, USA Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | - Kathleen A McDonough
- Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, Albany, NY 12201, USA Wadsworth Center, New York State Department of Health, 120 New Scotland Avenue, PO Box 22002, Albany, NY 12201-2002, USA
| |
Collapse
|
75
|
Whiteley AT, Pollock AJ, Portnoy DA. The PAMP c-di-AMP Is Essential for Listeria monocytogenes Growth in Rich but Not Minimal Media due to a Toxic Increase in (p)ppGpp. [corrected]. Cell Host Microbe 2015; 17:788-98. [PMID: 26028365 PMCID: PMC4469362 DOI: 10.1016/j.chom.2015.05.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/05/2015] [Accepted: 03/31/2015] [Indexed: 12/20/2022]
Abstract
Cyclic di-adenosine monophosphate (c-di-AMP) is a widely distributed second messenger that appears to be essential in multiple bacterial species, including the Gram-positive facultative intracellular pathogen Listeria monocytogenes. In this study, the only L. monocytogenes diadenylate cyclase gene, dacA, was deleted using a Cre-lox system activated during infection of cultured macrophages. All ΔdacA strains recovered from infected cells harbored one or more suppressor mutations that allowed growth in the absence of c-di-AMP. Suppressor mutations in the synthase domain of the bi-functional (p)ppGpp synthase/hydrolase led to reduced (p)ppGpp levels. A genetic assay confirmed that dacA was essential in wild-type but not strains lacking all three (p)ppGpp synthases. Further genetic analysis suggested that c-di-AMP was essential because accumulated (p)ppGpp altered GTP concentrations, thereby inactivating the pleiotropic transcriptional regulator CodY. We propose that c-di-AMP is conditionally essential for metabolic changes that occur in growth in rich medium and host cells but not minimal medium.
Collapse
Affiliation(s)
- Aaron T Whiteley
- Graduate Group in Infectious Diseases and Immunity, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Alex J Pollock
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Daniel A Portnoy
- Graduate Group in Infectious Diseases and Immunity, School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
| |
Collapse
|
76
|
Collins AC, Cai H, Li T, Franco LH, Li XD, Nair VR, Scharn CR, Stamm CE, Levine B, Chen ZJ, Shiloh MU. Cyclic GMP-AMP Synthase Is an Innate Immune DNA Sensor for Mycobacterium tuberculosis. Cell Host Microbe 2015; 17:820-8. [PMID: 26048137 DOI: 10.1016/j.chom.2015.05.005] [Citation(s) in RCA: 275] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 02/18/2015] [Accepted: 04/13/2015] [Indexed: 12/20/2022]
Abstract
Activation of the DNA-dependent cytosolic surveillance pathway in response to Mycobacterium tuberculosis infection stimulates ubiquitin-dependent autophagy and inflammatory cytokine production, and plays an important role in host defense against M. tuberculosis. However, the identity of the host sensor for M. tuberculosis DNA is unknown. Here we show that M. tuberculosis activated cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) in macrophages to produce cGAMP, a second messenger that activates the adaptor protein stimulator of interferon genes (STING) to induce type I interferons and other cytokines. cGAS localized with M. tuberculosis in mouse and human cells and in human tuberculosis lesions. Knockdown or knockout of cGAS in human or mouse macrophages blocked cytokine production and induction of autophagy. Mice deficient in cGAS were more susceptible to lethality caused by infection with M. tuberculosis. These results demonstrate that cGAS is a vital innate immune sensor of M. tuberculosis infection.
Collapse
Affiliation(s)
- Angela C Collins
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Haocheng Cai
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Tuo Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Luis H Franco
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA; Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Xiao-Dong Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
| | - Vidhya R Nair
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Caitlyn R Scharn
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Chelsea E Stamm
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Beth Levine
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA; Center for Autophagy Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA
| | - Zhijian J Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA.
| | - Michael U Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9113, USA.
| |
Collapse
|
77
|
Tang Q, Luo Y, Zheng C, Yin K, Ali MK, Li X, He J. Functional Analysis of a c-di-AMP-specific Phosphodiesterase MsPDE from Mycobacterium smegmatis. Int J Biol Sci 2015; 11:813-24. [PMID: 26078723 PMCID: PMC4466462 DOI: 10.7150/ijbs.11797] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 05/04/2015] [Indexed: 12/21/2022] Open
Abstract
Cyclic di‑AMP (c-di-AMP) is a second signaling molecule involved in the regulation of bacterial physiological processes and interaction between pathogen and host. However, the regulatory network mediated by c-di-AMP in Mycobacterium remains obscure. In M. smegmatis, a diadenylate cyclase (DAC) was reported recently, but there is still no investigation on c-di-AMP phosphodiesterase (PDE). Here, we provide a systematic study on signaling mechanism of c-di-AMP PDE in M. smegmatis. Based on our enzymatic analysis, MsPDE (MSMEG_2630), which contained a DHH-DHHA1 domain, displayed a 200-fold higher hydrolytic efficiency (kcat/Km) to c-di-AMP than to c-di-GMP. MsPDE was capable of converting c-di-AMP to pApA and AMP, and hydrolyzing pApA to AMP. Site-directed mutations in DHH and DHHA1 revealed that DHH domain was critical for the phosphodiesterase activity. To explore the regulatory role of c-di-AMP in vivo, we constructed the mspde mutant (Δmspde) and found that deficiency of MsPDE significantly enhanced intracellular C12-C20 fatty acid accumulation. Deficiency of DAC in many bacteria results in cell death. However, we acquired the M. smegmatis strain with DAC gene disrupted (ΔmsdisA) by homologous recombination approach. Deletion of msdisA reduced bacterial C12-C20 fatty acids production but scarcely affected bacterial survival. We also provided evidences that superfluous c-di-AMP in M. smegmatis could lead to abnormal colonial morphology. Collectively, our results indicate that MsPDE is a functional c-di-AMP-specific phosphodiesterase both in vitro and in vivo. Our study also expands the regulatory network mediated by c-di-AMP in M. smegmatis.
Collapse
Affiliation(s)
- Qing Tang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Yunchao Luo
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Cao Zheng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Kang Yin
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Maria Kanwal Ali
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Xinfeng Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| | - Jin He
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China
| |
Collapse
|
78
|
Kim H, Youn SJ, Kim SO, Ko J, Lee JO, Choi BS. Structural Studies of Potassium Transport Protein KtrA Regulator of Conductance of K+ (RCK) C Domain in Complex with Cyclic Diadenosine Monophosphate (c-di-AMP). J Biol Chem 2015; 290:16393-402. [PMID: 25957408 DOI: 10.1074/jbc.m115.641340] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Indexed: 11/06/2022] Open
Abstract
Although it was only recently identified as a second messenger, c-di-AMP was found to have fundamental importance in numerous bacterial functions such as ion transport. The potassium transporter protein, KtrA, was identified as a c-di-AMP receptor. However, the co-crystallization of c-di-AMP with the protein has not been studied. Here, we determined the crystal structure of the KtrA RCK_C domain in complex with c-di-AMP. The c-di-AMP nucleotide, which adopts a U-shaped conformation, is bound at the dimer interface of RCK_C close to helices α3 and α4. c-di-AMP interacts with KtrA RCK_C mainly by forming hydrogen bonds and hydrophobic interactions. c-di-AMP binding induces the contraction of the dimer, bringing the two monomers of KtrA RCK_C into close proximity. The KtrA RCK_C was able to interact with only c-di-AMP, but not with c-di-GMP, 3',3-cGAMP, ATP, and ADP. The structure of the KtrA RCK_C domain and c-di-AMP complex would expand our understanding about the mechanism of inactivation in Ktr transporters governed by c-di-AMP.
Collapse
Affiliation(s)
- Henna Kim
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Suk-Jun Youn
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Seong Ok Kim
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Junsang Ko
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jie-Oh Lee
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Byong-Seok Choi
- From the Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| |
Collapse
|
79
|
Intracellular Concentrations of Borrelia burgdorferi Cyclic Di-AMP Are Not Changed by Altered Expression of the CdaA Synthase. PLoS One 2015; 10:e0125440. [PMID: 25906393 PMCID: PMC4408052 DOI: 10.1371/journal.pone.0125440] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 03/12/2015] [Indexed: 01/10/2023] Open
Abstract
The second messenger nucleotide cyclic diadenylate monophosphate (c-di-AMP) has been identified in several species of Gram positive bacteria and Chlamydia trachomatis. This molecule has been associated with bacterial cell division, cell wall biosynthesis and phosphate metabolism, and with induction of type I interferon responses by host cells. We demonstrate that B. burgdorferi produces a c-di-AMP synthase, which we designated CdaA. Both CdaA and c-di-AMP levels are very low in cultured B. burgdorferi, and no conditions were identified under which cdaA mRNA was differentially expressed. A mutant B. burgdorferi was produced that expresses high levels of CdaA, yet steady state borrelial c-di-AMP levels did not change, apparently due to degradation by the native DhhP phosphodiesterase. The function(s) of c-di-AMP in the Lyme disease spirochete remains enigmatic.
Collapse
|
80
|
A bacterial cyclic dinucleotide activates the cytosolic surveillance pathway and mediates innate resistance to tuberculosis. Nat Med 2015; 21:401-6. [PMID: 25730264 PMCID: PMC4390473 DOI: 10.1038/nm.3813] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 02/03/2015] [Indexed: 12/14/2022]
Abstract
Detection of cyclic-di-adenosine monophosphate (c-di-AMP), a bacterial second messenger, by the host cytoplasmic surveillance pathway (CSP) is known to elicit Type I interferon responses critical for antimicrobial defense1–3. However, the mechanisms and role of c-di-AMP signaling in Mycobacterium tuberculosis virulence remain unclear. Here we show that resistance to tuberculosis (TB) requires CSP-mediated detection of c-di-AMP produced by M. tuberculosis and that levels of c-di-AMP modulate the fate of infection. We found that a di-adenylate cyclase (disA or dacA)4 over-expressing M. tuberculosis strain that secretes excess c-di-AMP activates the interferon regulatory factor (IRF) pathway with enhanced levels of IFN-β, elicits increased macrophage autophagy, and exhibits significant attenuation in mice. We show that c-di-AMP-mediated IFN-β induction during M. tuberculosis infection requires stimulator of interferon genes (STING)5-signaling. We observed that c-di-AMP induction of IFN-β is independent of the cytosolic nucleic acid receptor cyclic-GMP-AMP (cGAMP) synthase (cGAS)6–7, but cGAS nevertheless contributes substantially to the overall IFN-β response to M. tuberculosis infection. In sum, our results reveal c-di-AMP to be a key mycobacterial pathogen associated molecular pattern (PAMP) driving host Type I IFN responses and autophagy. These findings suggest that modulating the levels of this small molecule may lead to novel immunotherapeutic strategies against TB.
Collapse
|
81
|
Sureka K, Choi PH, Precit M, Delince M, Pensinger DA, Huynh TN, Jurado AR, Goo YA, Sadilek M, Iavarone AT, Sauer JD, Tong L, Woodward JJ. The cyclic dinucleotide c-di-AMP is an allosteric regulator of metabolic enzyme function. Cell 2014; 158:1389-1401. [PMID: 25215494 DOI: 10.1016/j.cell.2014.07.046] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/09/2014] [Accepted: 07/29/2014] [Indexed: 12/13/2022]
Abstract
Cyclic di-adenosine monophosphate (c-di-AMP) is a broadly conserved second messenger required for bacterial growth and infection. However, the molecular mechanisms of c-di-AMP signaling are still poorly understood. Using a chemical proteomics screen for c-di-AMP-interacting proteins in the pathogen Listeria monocytogenes, we identified several broadly conserved protein receptors, including the central metabolic enzyme pyruvate carboxylase (LmPC). Biochemical and crystallographic studies of the LmPC-c-di-AMP interaction revealed a previously unrecognized allosteric regulatory site 25 Å from the active site. Mutations in this site disrupted c-di-AMP binding and affected catalytic activity of LmPC as well as PC from pathogenic Enterococcus faecalis. C-di-AMP depletion resulted in altered metabolic activity in L. monocytogenes. Correction of this metabolic imbalance rescued bacterial growth, reduced bacterial lysis, and resulted in enhanced bacterial burdens during infection. These findings greatly expand the c-di-AMP signaling repertoire and reveal a central metabolic regulatory role for a cyclic dinucleotide.
Collapse
Affiliation(s)
- Kamakshi Sureka
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Mimi Precit
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Matthieu Delince
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Daniel A Pensinger
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - TuAnh Ngoc Huynh
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA
| | - Ashley R Jurado
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Young Ah Goo
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD 21201, USA
| | - Martin Sadilek
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Anthony T Iavarone
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, CA 94720, USA
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
82
|
Dey B, Bishai WR. Crosstalk between Mycobacterium tuberculosis and the host cell. Semin Immunol 2014; 26:486-96. [PMID: 25303934 DOI: 10.1016/j.smim.2014.09.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 09/02/2014] [Indexed: 11/15/2022]
Abstract
The successful establishment and maintenance of a bacterial infection depend on the pathogen's ability to subvert the host cell's defense response and successfully survive, proliferate, or persist within the infected cell. To circumvent host defense systems, bacterial pathogens produce a variety of virulence factors that potentiate bacterial adherence and invasion and usurp host cell signaling cascades that regulate intracellular microbial survival and trafficking. Mycobacterium tuberculosis, probably one of the most successful pathogens on earth, has coexisted with humanity for centuries, and this intimate and persistent connection between these two organisms suggests that the pathogen has evolved extensive mechanisms to evade the human immune system at multiple levels. While some of these mechanisms are mediated by factors released by M. tuberculosis, others rely on host components that are hijacked to prevent the generation of an effective immune response thus benefiting the survival of M. tuberculosis within the host cell. Here, we describe several of these mechanisms, with an emphasis on the cyclic nucleotide signaling and subversion of host responses that occur at the intracellular level when tubercle bacilli encounter macrophages, a cell that becomes a safe-house for M. tuberculosis although it is specialized to kill most microbes.
Collapse
Affiliation(s)
- Bappaditya Dey
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - William R Bishai
- Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
| |
Collapse
|
83
|
Underwood AJ, Zhang Y, Metzger DW, Bai G. Detection of cyclic di-AMP using a competitive ELISA with a unique pneumococcal cyclic di-AMP binding protein. J Microbiol Methods 2014; 107:58-62. [PMID: 25239824 DOI: 10.1016/j.mimet.2014.08.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 08/18/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
Cyclic di-AMP (c-di-AMP) is a recently recognized bacterial signaling molecule. In this study, a competitive enzyme-linked immunosorbent assay (ELISA) for the quantification of c-di-AMP was developed using a novel pneumococcal c-di-AMP binding protein (CabP). With this method, c-di-AMP concentrations in biological samples can be quickly and accurately quantified.
Collapse
Affiliation(s)
- Adam J Underwood
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, Albany, NY 12208-3479, USA
| | - Yang Zhang
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, Albany, NY 12208-3479, USA
| | - Dennis W Metzger
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, Albany, NY 12208-3479, USA
| | - Guangchun Bai
- Center for Immunology and Microbial Disease, MC-151, Albany Medical College, Albany, NY 12208-3479, USA.
| |
Collapse
|