51
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Lu T, Cao Q, Pang X, Xia Y, Xun L, Liu H. Sulfane sulfur-activated actinorhodin production and sporulation is maintained by a natural gene circuit in Streptomyces coelicolor. Microb Biotechnol 2020; 13:1917-1932. [PMID: 32776457 PMCID: PMC7533328 DOI: 10.1111/1751-7915.13637] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 01/25/2023] Open
Abstract
Sulfane sulfur, including polysulfide and persulfide, is a newly identified cellular component present in microorganisms; however, its physiological functions are unclear. Streptomyces coelicolor M145 is a model strain of actinomycetes, which produces several polyketides, including actinorhodin. Herein, we found that both exogenously added and endogenously generated sulfane sulfur increased the actinorhodin production and accelerated spore formation of S. coelicolor M145. This bacterial species carries a natural gene circuit containing four genes that encode a CsoR-like transcription factor (ScCsoR), persulfide dioxygenase (ScPDO), rhodanese and a sulfite transporter, which were shown to be responsible for sensing and removal of excessive sulfane sulfur. ScCsoR was observed to bind to the promoters of the four genes, thus repressing their transcription. Sulfane sulfur modified Cys37 of ScCsoR, and the modified ScCSoR did not bind to the promoters, thereby activating the transcription of ScPDO. The deletion of ScCsoR decreased cellular sulfane sulfur, while the deletion of ScPDO increased its levels. The increased sulfane sulfur promoted actinorhodin production and sporulation. This study unveiled a natural gene circuit for maintaining sulfane sulfur homeostasis in bacteria. Further, we identified the trigger effect of sulfane sulfur on actinorhodin production, presenting a new approach for activating polyketide gene clusters in actinomycetes.
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Affiliation(s)
- Ting Lu
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
| | - Qun Cao
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
| | - Xiuhua Pang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
| | - Yongzhen Xia
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
| | - Luying Xun
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
- School of Molecular BiosciencesWashington State UniversityPullmanWA991647520USA
| | - Huaiwei Liu
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266200China
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52
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Haist J, Neumann SA, Al-Bassam MM, Lindenberg S, Elliot MA, Tschowri N. Specialized and shared functions of diguanylate cyclases and phosphodiesterases in Streptomyces development. Mol Microbiol 2020; 114:808-822. [PMID: 32797697 DOI: 10.1111/mmi.14581] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/20/2020] [Indexed: 12/26/2022]
Abstract
The second messenger bis-3,5-cyclic di-guanosine monophosphate (c-di-GMP) determines when Streptomyces initiate sporulation. c-di-GMP signals are integrated into the genetic differentiation network by the regulator BldD and the sigma factor σWhiG . However, functions of the development-specific diguanylate cyclases (DGCs) CdgB and CdgC, and the c-di-GMP phosphodiesterases (PDEs) RmdA and RmdB, are poorly understood. Here, we provide biochemical evidence that the GGDEF-EAL domain protein RmdB from S. venezuelae is a monofunctional PDE that hydrolyzes c-di-GMP to 5'pGpG. Despite having an equivalent GGDEF-EAL domain arrangement, RmdA cleaves c-di-GMP to GMP and exhibits residual DGC activity. We show that an intact EAL motif is crucial for the in vivo function of both enzymes since strains expressing protein variants with an AAA motif instead of EAL are delayed in development, similar to null mutants. Transcriptome analysis of ∆cdgB, ∆cdgC, ∆rmdA, and ∆rmdB strains revealed that the c-di-GMP specified by these enzymes has a global regulatory role, with about 20% of all S. venezuelae genes being differentially expressed in the cdgC mutant. Our data suggest that the major c-di-GMP-controlled targets determining the timing and mode of sporulation are genes involved in cell division and the production of the hydrophobic sheath that covers Streptomyces aerial hyphae and spores.
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Affiliation(s)
- Julian Haist
- Department of Biology/Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sara Alina Neumann
- Department of Biology/Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - Sandra Lindenberg
- Department of Biology/Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Marie A Elliot
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Natalia Tschowri
- Department of Biology/Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
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53
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Wang C, Ren X, Yu C, Wang J, Wang L, Zhuge X, Liu X. Physiological and Transcriptional Responses of Streptomyces albulus to Acid Stress in the Biosynthesis of ε-Poly-L-lysine. Front Microbiol 2020; 11:1379. [PMID: 32636829 PMCID: PMC7317143 DOI: 10.3389/fmicb.2020.01379] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
Streptomyces albulus has commercially been used for the production of ε-poly-L-lysine (ε-PL), a natural food preservative, where acid stress is inevitably encountered in the biosynthesis process. To elucidate the acid tolerance response (ATR), a comparative physiology and transcriptomic analysis of S. albulus M-Z18 at different environmental pH (5.0, 4.0, and 3.0) was carried out. In response to acid stress, cell envelope regulated the membrane fatty acid composition and chain length to reduce damage. Moreover, intracellular pH homeostasis was maintained by increasing H+-ATPase activity and intracellular ATP and amino acid (mainly arginine, glutamate, aspartate and lysine) concentrations. Transcriptional analysis based on RNA-sequencing indicated that acid stress aroused global changes and the differentially expressed genes involved in transcriptional regulation, stress-response protein, transporter, cell envelope, secondary metabolite biosynthesis, DNA and RNA metabolism and ribosome subunit. Consequently, the ATR of S. albulus was preliminarily proposed. Notably, it is indicated that the biosynthesis of ε-PL is also a response mechanism for S. albulus to combat acid stress. These results provide new insights into the ATR of S. albulus and will contribute to the production of ε-PL via adaptive evolution or metabolic engineering.
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Affiliation(s)
- Chenying Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Xidong Ren
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Chao Yu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Junming Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Li Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Xin Zhuge
- Process Development Department, IntellectiveBio Co., Ltd., Suzhou, China
| | - Xinli Liu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
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54
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Kim W, Lee N, Hwang S, Lee Y, Kim J, Cho S, Palsson B, Cho BK. Comparative Genomics Determines Strain-Dependent Secondary Metabolite Production in Streptomyces venezuelae Strains. Biomolecules 2020; 10:biom10060864. [PMID: 32516997 PMCID: PMC7357120 DOI: 10.3390/biom10060864] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/30/2020] [Accepted: 06/01/2020] [Indexed: 02/02/2023] Open
Abstract
Streptomyces venezuelae is well known to produce various secondary metabolites, including chloramphenicol, jadomycin, and pikromycin. Although many strains have been classified as S. venezuelae species, only a limited number of strains have been explored extensively for their genomic contents. Moreover, genomic differences and diversity in secondary metabolite production between the strains have never been compared. Here, we report complete genome sequences of three S. venezuelae strains (ATCC 10712, ATCC 10595, and ATCC 21113) harboring chloramphenicol and jadomycin biosynthetic gene clusters (BGC). With these high-quality genome sequences, we revealed that the three strains share more than 85% of total genes and most of the secondary metabolite biosynthetic gene clusters (smBGC). Despite such conservation, the strains produced different amounts of chloramphenicol and jadomycin, indicating differential regulation of secondary metabolite production at the strain level. Interestingly, antagonistic production of chloramphenicol and jadomycin was observed in these strains. Through comparison of the chloramphenicol and jadomycin BGCs among the three strains, we found sequence variations in many genes, the non-coding RNA coding regions, and binding sites of regulators, which affect the production of the secondary metabolites. We anticipate that these genome sequences of closely related strains would serve as useful resources for understanding the complex secondary metabolism and for designing an optimal production process using Streptomyces strains.
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Affiliation(s)
- Woori Kim
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Namil Lee
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Soonkyu Hwang
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Yongjae Lee
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Jihun Kim
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Suhyung Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
| | - Bernhard Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093, USA;
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Byung-Kwan Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (W.K.); (N.L.); (S.H.); (Y.L.); (J.K.); (S.C.)
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Lyngby, Denmark
- Intelligent Synthetic Biology Center, Daejeon 34141, Korea
- Correspondence: ; Tel.: +82-42-350-2660
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55
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Becher PG, Verschut V, Bibb MJ, Bush MJ, Molnár BP, Barane E, Al-Bassam MM, Chandra G, Song L, Challis GL, Buttner MJ, Flärdh K. Developmentally regulated volatiles geosmin and 2-methylisoborneol attract a soil arthropod to Streptomyces bacteria promoting spore dispersal. Nat Microbiol 2020; 5:821-829. [DOI: 10.1038/s41564-020-0697-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 02/21/2020] [Indexed: 12/28/2022]
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56
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Chou SH, Galperin MY. Cyclic di-GMP in Streptomycetes: A New Conformation, New Binding Mode, New Receptor, and a New Mechanism to Control Cell Development. Mol Cell 2020; 77:443-445. [PMID: 32032510 DOI: 10.1016/j.molcel.2020.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A recent paper by Gallagher et al. (2020) demonstrates that c-di-GMP controls spore formation in Streptomyces venezuelae through sequestering the sporulation sigma factor σWhiG and presents the crystal structure of a ternary complex between c-di-GMP, σWhiG, and its anti-sigma factor, RsiG.
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Affiliation(s)
- Shan-Ho Chou
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Institute of Biochemistry and Agricultural Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China.
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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57
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c-di-AMP hydrolysis by the phosphodiesterase AtaC promotes differentiation of multicellular bacteria. Proc Natl Acad Sci U S A 2020; 117:7392-7400. [PMID: 32188788 PMCID: PMC7132281 DOI: 10.1073/pnas.1917080117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bacteria use the nucleotide cyclic di-3′,5′-adenosine monophosphate (c-di-AMP) for adaptation to changing environments and host–pathogen interactions. Enzymes for nucleotide synthesis and degradation and proteins for binding of the second messenger are key components of signal transduction pathways. It was long unknown how the majority of Actinobacteria, one of the largest bacterial phyla, stop c-di-AMP signals and which proteins bind the molecule to elicit cellular responses. Here, we identify a c-di-AMP phosphodiesterase that bacteria evolved to terminate c-di-AMP signaling and a protein that forms a complex with c-di-AMP in Streptomyces. We also demonstrate that balance of c-di-AMP is critical for developmental transitions from filaments to spores in multicellular bacteria. Antibiotic-producing Streptomyces use the diadenylate cyclase DisA to synthesize the nucleotide second messenger c-di-AMP, but the mechanism for terminating c-di-AMP signaling and the proteins that bind the molecule to effect signal transduction are unknown. Here, we identify the AtaC protein as a c-di-AMP-specific phosphodiesterase that is also conserved in pathogens such as Streptococcus pneumoniae and Mycobacterium tuberculosis. AtaC is monomeric in solution and binds Mn2+ to specifically hydrolyze c-di-AMP to AMP via the intermediate 5′-pApA. As an effector of c-di-AMP signaling, we characterize the RCK_C domain protein CpeA. c-di-AMP promotes interaction between CpeA and the predicted cation/proton antiporter, CpeB, linking c-di-AMP signaling to ion homeostasis in Actinobacteria. Hydrolysis of c-di-AMP is critical for normal growth and differentiation in Streptomyces, connecting ionic stress to development. Thus, we present the discovery of two components of c-di-AMP signaling in bacteria and show that precise control of this second messenger is essential for ion balance and coordinated development in Streptomyces.
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58
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Hashiguchi Y, Tezuka T, Ohnishi Y. Involvement of three FliA-family sigma factors in the sporangium formation, spore dormancy and sporangium dehiscence in Actinoplanes missouriensis. Mol Microbiol 2020; 113:1170-1188. [PMID: 32052506 DOI: 10.1111/mmi.14485] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/08/2020] [Accepted: 02/09/2020] [Indexed: 12/27/2022]
Abstract
The rare actinomycete Actinoplanes missouriensis forms sporangia, which open up and release zoospores in response to water. Here, we report a genetic and functional analysis of four FliA-family sigma factors, FliA1, FliA2, FliA3 and FliA4. Transcription of fliA1, fliA2 and fliA3 was directly activated by the global transcriptional activator TcrA during sporangium formation and dehiscence, while fliA4 was almost always transcribed at low levels. Gene disruption analysis showed that (a) deletion of fliA2 reduced the zoospore swimming speed by half, (b) the fliA1-fliA2 double-deletion mutant formed abnormal sporangia in which mutant spores ectopically germinated and (c) deletion of fliA3 induced no phenotypic changes in the wild-type and mutant strains of fliA1 and/or fliA2. Comparative RNA-Seq analyses among the wild-type and gene deletion mutant strains showed probable targets of each FliA-family sigma factor, indicating that FliA1- and FliA2-dependent promoters are quite similar to each other, while the FliA3-dependent promoter is somewhat different. Gene complementation experiments also indicated that the FliA1 regulon overlaps with the FliA2 regulon. These results demonstrate that A. missouriensis has developed a complex transcriptional regulatory network involving multiple FliA-family sigma factors for the accomplishment of its characteristic reproduction process, including sporangium formation, spore dormancy and sporangium dehiscence.
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Affiliation(s)
- Yuichiro Hashiguchi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takeaki Tezuka
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
| | - Yasuo Ohnishi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan
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59
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Dorman CJ, Schumacher MA, Bush MJ, Brennan RG, Buttner MJ. When is a transcription factor a NAP? Curr Opin Microbiol 2020; 55:26-33. [PMID: 32120333 DOI: 10.1016/j.mib.2020.01.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 02/03/2023]
Abstract
Proteins that regulate transcription often also play an architectural role in the genome. Thus, it has been difficult to define with precision the distinctions between transcription factors and nucleoid-associated proteins (NAPs). Anachronistic descriptions of NAPs as 'histone-like' implied an organizational function in a bacterial chromatin-like complex. Definitions based on protein abundance, regulatory mechanisms, target gene number, or the features of their DNA-binding sites are insufficient as marks of distinction, and trying to distinguish transcription factors and NAPs based on their ranking within regulatory hierarchies or positions in gene-control networks is also unsatisfactory. The terms 'transcription factor' and 'NAP' are ad hoc operational definitions with each protein lying along a spectrum of structural and functional features extending from highly specific actors with few gene targets to those with a pervasive influence on the transcriptome. The Streptomyces BldC protein is used to illustrate these issues.
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Affiliation(s)
- Charles J Dorman
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland.
| | - Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
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60
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Latoscha A, Wörmann ME, Tschowri N. Nucleotide second messengers in Streptomyces. MICROBIOLOGY-SGM 2020; 165:1153-1165. [PMID: 31535967 DOI: 10.1099/mic.0.000846] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Antibiotic producing Streptomyces sense and respond to environmental signals by using nucleotide second messengers, including (p)ppGpp, cAMP, c-di-GMP and c-di-AMP. As summarized in this review, these molecules are important message carriers that coordinate the complex Streptomyces morphological transition from filamentous growth to sporulation along with the secondary metabolite production. Here, we provide an overview of the enzymes that make and break these second messengers and suggest candidates for (p)ppGpp and cAMP enzymes to be studied. We highlight the target molecules that bind these signalling molecules and elaborate individual functions that they control in the context of Streptomyces development. Finally, we discuss open questions in the field, which may guide future studies in this exciting research area.
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Affiliation(s)
- Andreas Latoscha
- Department of Biology / Microbiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Mirka E Wörmann
- Department of Biology / Microbiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Natalia Tschowri
- Department of Biology / Microbiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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61
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Gallagher KA, Schumacher MA, Bush MJ, Bibb MJ, Chandra G, Holmes NA, Zeng W, Henderson M, Zhang H, Findlay KC, Brennan RG, Buttner MJ. c-di-GMP Arms an Anti-σ to Control Progression of Multicellular Differentiation in Streptomyces. Mol Cell 2020; 77:586-599.e6. [PMID: 31810759 PMCID: PMC7005675 DOI: 10.1016/j.molcel.2019.11.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/22/2019] [Accepted: 11/04/2019] [Indexed: 12/31/2022]
Abstract
Streptomyces are our primary source of antibiotics, produced concomitantly with the transition from vegetative growth to sporulation in a complex developmental life cycle. We previously showed that the signaling molecule c-di-GMP binds BldD, a master repressor, to control initiation of development. Here we demonstrate that c-di-GMP also intervenes later in development to control differentiation of the reproductive hyphae into spores by arming a novel anti-σ (RsiG) to bind and sequester a sporulation-specific σ factor (σWhiG). We present the structure of the RsiG-(c-di-GMP)2-σWhiG complex, revealing an unusual, partially intercalated c-di-GMP dimer bound at the RsiG-σWhiG interface. RsiG binds c-di-GMP in the absence of σWhiG, employing a novel E(X)3S(X)2R(X)3Q(X)3D motif repeated on each helix of a coiled coil. Further studies demonstrate that c-di-GMP is essential for RsiG to inhibit σWhiG. These findings reveal a newly described control mechanism for σ-anti-σ complex formation and establish c-di-GMP as the central integrator of Streptomyces development.
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Affiliation(s)
- Kelley A. Gallagher
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maria A. Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA,Corresponding author
| | - Matthew J. Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maureen J. Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Neil A. Holmes
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Wenjie Zeng
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Max Henderson
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hengshan Zhang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kim C. Findlay
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard G. Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mark J. Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK,Corresponding author
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62
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Smith RP, Barraza I, Quinn RJ, Fortoul MC. The mechanisms and cell signaling pathways of programmed cell death in the bacterial world. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 352:1-53. [PMID: 32334813 DOI: 10.1016/bs.ircmb.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
While programmed cell death was once thought to be exclusive to eukaryotic cells, there are now abundant examples of well regulated cell death mechanisms in bacteria. The mechanisms by which bacteria undergo programmed cell death are diverse, and range from the use of toxin-antitoxin systems, to prophage-driven cell lysis. Moreover, some bacteria have learned how to coopt programmed cell death systems in competing bacteria. Interestingly, many of the potential reasons as to why bacteria undergo programmed cell death may parallel those observed in eukaryotic cells, and may be altruistic in nature. These include protection against infection, recycling of nutrients, to ensure correct morphological development, and in response to stressors. In the following chapter, we discuss the molecular and signaling mechanisms by which bacteria undergo programmed cell death. We conclude by discussing the current open questions in this expanding field.
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Affiliation(s)
- Robert P Smith
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States.
| | - Ivana Barraza
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Rebecca J Quinn
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Marla C Fortoul
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL, United States
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63
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Critical Assessment of Streptomyces spp. Able to Control Toxigenic Fusaria in Cereals: A Literature and Patent Review. Int J Mol Sci 2019; 20:ijms20246119. [PMID: 31817248 PMCID: PMC6941072 DOI: 10.3390/ijms20246119] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 11/18/2019] [Accepted: 12/01/2019] [Indexed: 12/18/2022] Open
Abstract
Mycotoxins produced by Fusarium species on cereals represent a major concern for food safety worldwide. Fusarium toxins that are currently under regulation for their content in food include trichothecenes, fumonisins, and zearalenone. Biological control of Fusarium spp. has been widely explored with the aim of limiting disease occurrence, but few efforts have focused so far on limiting toxin accumulation in grains. The bacterial genus Streptomyces is responsible for the production of numerous drug molecules and represents a huge resource for the discovery of new molecules. Streptomyces spp. are also efficient plant colonizers and able to employ different mechanisms of control against toxigenic fungi on cereals. This review describes the outcomes of research using Streptomyces strains and/or their derived molecules to limit toxin production and/or contamination of Fusarium species in cereals. Both the scientific and patent literature were analyzed, starting from the year 2000, and we highlight promising results as well as the current pitfalls and limitations of this approach.
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Yan H, Lu X, Sun D, Zhuang S, Chen Q, Chen Z, Li J, Wen Y. BldD, a master developmental repressor, activates antibiotic production in two Streptomyces species. Mol Microbiol 2019; 113:123-142. [PMID: 31628680 DOI: 10.1111/mmi.14405] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2019] [Indexed: 02/07/2023]
Abstract
BldD generally functions as a repressor controlling morphological development of Streptomyces. In this work, evidences that BldD also activates antibiotic production are provided. In Streptomyces roseosporus (which produces daptomycin widely used for treatment of human infections), deletion of bldD notably reduced daptomycin production, but enhanced sporulation. BldD stimulated daptomycin production by directly activating transcription of dpt structural genes and dptR3 (which encodes an indirect activator of daptomycin production), and repressed its own gene. BldD-binding sites on promoter regions of dptE, dptR3, and bldD were all found to contain BldD box-like sequences, facilitating prediction of new BldD targets. Two Streptomyces global regulatory genes, adpA and afsR, were confirmed to be directly activated by BldD. The protein AfsR was shown to act as an activator of daptomycin production, but a repressor of development. BldD directly represses nine key developmental genes. In Streptomyces avermitilis (which produces effective anthelmintic agents avermectins), BldD homolog (BldDsav) directly activates avermectin production through ave structural genes and cluster-situated activator gene aveR. This is the first report that BldD activates antibiotic biosynthesis both directly and via a cascade mechanism. BldD homologs are widely distributed among Streptomyces, our findings suggest that BldD may activate antibiotic production in other Streptomyces species.
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Affiliation(s)
- Hao Yan
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiaorui Lu
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Di Sun
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Shuai Zhuang
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qiong Chen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jilun Li
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ying Wen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
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Musiol-Kroll EM, Tocchetti A, Sosio M, Stegmann E. Challenges and advances in genetic manipulation of filamentous actinomycetes - the remarkable producers of specialized metabolites. Nat Prod Rep 2019; 36:1351-1369. [PMID: 31517370 DOI: 10.1039/c9np00029a] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Covering: up to February 2019Actinomycetes are Gram positive bacteria of the phylum Actinobacteria. These organisms are one of the most important sources of structurally diverse, clinically used antibiotics and other valuable bioactive products, as well as biotechnologically relevant enzymes. Most strains were discovered by their ability to produce a given molecule and were often poorly characterized, physiologically and genetically. The development of genetic methods for Streptomyces and related filamentous actinomycetes has led to the successful manipulation of antibiotic biosynthesis to attain structural modification of microbial metabolites that would have been inaccessible by chemical means and improved production yields. Moreover, genome mining reveals that actinomycete genomes contain multiple biosynthetic gene clusters (BGCs), however only a few of them are expressed under standard laboratory conditions, leading to the production of the respective compound(s). Thus, to access and activate the so-called "silent" BGCs, to improve their biosynthetic potential and to discover novel natural products methodologies for genetic manipulation are required. Although different methods have been applied for many actinomycete strains, genetic engineering is still remaining very challenging for some "underexplored" and poorly characterized actinomycetes. This review summarizes the strategies developed to overcome the obstacles to genetic manipulation of actinomycetes and allowing thereby rational genetic engineering of this industrially relevant group of microorganisms. At the end of this review we give some tips to researchers with limited or no previous experience in genetic manipulation of actinomycetes. The article covers the most relevant literature published until February 2019.
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Affiliation(s)
- Ewa M Musiol-Kroll
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Microbiology/Biotechnology, Auf der Morgenstelle 28, Tübingen, 72076, Germany.
| | | | | | - Evi Stegmann
- University of Tübingen, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Microbiology/Biotechnology, Auf der Morgenstelle 28, Tübingen, 72076, Germany.
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Schumacher MA, Bush MJ, Bibb MJ, Ramos-León F, Chandra G, Zeng W, Buttner MJ. The crystal structure of the RsbN-σBldN complex from Streptomyces venezuelae defines a new structural class of anti-σ factor. Nucleic Acids Res 2019; 46:7405-7417. [PMID: 29905823 PMCID: PMC6101532 DOI: 10.1093/nar/gky493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/24/2018] [Indexed: 11/13/2022] Open
Abstract
Streptomyces are filamentous bacteria with a complex developmental life cycle characterized by the formation of spore-forming aerial hyphae. Transcription of the chaplin and rodlin genes, which are essential for aerial hyphae production, is directed by the extracytoplasmic function (ECF) σ factor BldN, which is in turn controlled by an anti-σ factor, RsbN. RsbN shows no sequence similarity to known anti-σ factors and binds and inhibits BldN in an unknown manner. Here we describe the 2.23 Å structure of the RsbN–BldN complex. The structure shows that BldN harbors σ2 and σ4 domains that are individually similar to other ECF σ domains, which bind −10 and −35 promoter regions, respectively. The anti-σ RsbN consists of three helices, with α3 forming a long helix embraced between BldN σ2 and σ4 while RsbN α1–α2 dock against σ4 in a manner that would block −35 DNA binding. RsbN binding also freezes BldN in a conformation inactive for simultaneous −10 and −35 promoter interaction and RNAP binding. Strikingly, RsbN is structurally distinct from previously solved anti-σ proteins. Thus, these data characterize the molecular determinants controlling a central Streptomyces developmental switch and reveal RsbN to be the founding member of a new structural class of anti-σ factor.
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Affiliation(s)
- Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Maureen J Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Félix Ramos-León
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Wenjie Zeng
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
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cyAbrB Transcriptional Regulators as Safety Devices To Inhibit Heterocyst Differentiation in Anabaena sp. Strain PCC 7120. J Bacteriol 2019; 201:JB.00244-19. [PMID: 31085690 DOI: 10.1128/jb.00244-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Cyanobacteria are monophyletic organisms that perform oxygenic photosynthesis. While they exhibit great diversity, they have a common set of genes. However, the essentiality of them for viability has hampered the elucidation of their functions. One example of these genes is cyabrB1 (also known as calA in Anabaena sp. strain PCC 7120), encoding a transcriptional regulator. In the present study, we investigated the function of calA/cyabrB1 in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 through CRISPR interference, a method that we recently utilized for the photosynthetic production of a useful chemical in this strain. Conditional knockdown of calA/cyabrB1 in the presence of nitrate resulted in the formation of heterocysts. Two genes, hetP and hepA, which are required for heterocyst formation, were upregulated by calA/cyabrB1 knockdown in the presence of combined nitrogen sources. These genes are known to be induced by HetR, a master regulator of heterocyst formation. hetR was not induced by calA/cyabrB1 knockdown. hetP and hepA were repressed by direct binding of CalA/cyAbrB1 to their promoter regions in a HetR-independent manner. In addition, the overexpression of calA/cyabrB1 abolished heterocyst formation upon nitrogen depletion. Also, knockout of calB/cyabrB2 (a paralogue gene of calA/cyabrB1), in addition to knockdown of calA/cyabrB1, enhanced heterocyst formation in the presence of nitrate, suggesting functional redundancy of cyAbrB proteins. We propose that a balance between amounts of HetR and CalA/cyAbrB1 is a key factor influencing heterocyst differentiation during nitrogen stepdown. We concluded that cyAbrB proteins are essential safety devices that inhibit heterocyst differentiation.IMPORTANCE Spore formation in Bacillus subtilis and Streptomyces has been extensively studied as models of prokaryotic nonterminal cell differentiation. In these organisms, many cells/hyphae differentiate simultaneously, which is governed by a network in which one regulator stands at the top. Differentiation of heterocysts in Anabaena sp. strain PCC 7120 is unique because it is terminal, and only 5 to 10% of vegetative cells differentiate into heterocysts. In this study, we identified CalA/cyAbrB1 as a repressor of two genes that are essential for heterocyst formation independently of HetR, a master activator for heterocyst differentiation. This finding is reasonable for unique cell differentiation of Anabaena because CalA/cyAbrB1 could suppress heterocyst differentiation tightly in vegetative cells, while only cells in which HetR is overexpressed could differentiate into heterocysts.
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68
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Szafran MJ, Strzałka A, Jakimowicz D. A highly processive actinobacterial topoisomerase I - thoughts on Streptomyces' demand for an enzyme with a unique C-terminal domain. MICROBIOLOGY-SGM 2019; 166:120-128. [PMID: 31390324 PMCID: PMC7398561 DOI: 10.1099/mic.0.000841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Topoisomerase I (TopA) is an essential enzyme that is required to remove excess negative supercoils from chromosomal DNA. Actinobacteria encode unusual TopA homologues with a unique C-terminal domain that contains lysine repeats and confers high enzyme processivity. Interestingly, the longest stretch of lysine repeats was identified in TopA from Streptomyces, environmental bacteria that undergo complex differentiation and produce a plethora of secondary metabolites. In this review, we aim to discuss potential advantages of the lysine repeats in Streptomyces TopA. We speculate that the chromosome organization, transcriptional regulation and lifestyle of these species demand a highly processive but also fine-tuneable relaxase. We hypothesize that the unique TopA provides flexible control of chromosomal topology and globally regulates gene expression.
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Affiliation(s)
- Marcin J Szafran
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Agnieszka Strzałka
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Dagmara Jakimowicz
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
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69
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Vollmer B, Steblau N, Ladwig N, Mayer C, Macek B, Mitousis L, Sigle S, Walter A, Wohlleben W, Muth G. Role of the Streptomyces spore wall synthesizing complex SSSC in differentiation of Streptomyces coelicolor A3(2). Int J Med Microbiol 2019; 309:151327. [PMID: 31324525 DOI: 10.1016/j.ijmm.2019.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 07/02/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022] Open
Abstract
A crucial stage of the Streptomyces life cycle is the sporulation septation, a process were dozens of cross walls are synchronously formed in the aerial hyphae in a highly coordinated manner. This process includes the remodeling of the spore envelopes to make Streptomyces spores resistant to detrimental environmental conditions. Sporulation septation and the synthesis of the thickened spore envelope in S. coelicolor A3(2) involves the Streptomyces spore wall synthesizing complex SSSC. The SSSC is a multi-protein complex including proteins directing peptidoglycan synthesis (MreBCD, PBP2, Sfr, RodZ) and cell wall glycopolymer synthesis (PdtA). It also includes two eukaryotic like serin/threonine protein kinases (eSTPK), PkaI and PkaH, which were shown to phosphorylate MreC. Since unbalancing phosphorylation activity by either deleting eSTPK genes or by expressing a second copy of an eSTPK gene affected proper sporulation, a model was developed, in which the activity of the SSSC is controlled by protein phosphorylation.
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Affiliation(s)
- B Vollmer
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - N Steblau
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - N Ladwig
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - C Mayer
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - B Macek
- Proteome Center Tuebingen, Interfakultaeres Institut für Zellbiologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - L Mitousis
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - S Sigle
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - A Walter
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - W Wohlleben
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany
| | - G Muth
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076, Tuebingen, Germany.
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70
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Arroyo-Pérez EE, González-Cerón G, Soberón-Chávez G, Georgellis D, Servín-González L. A Novel Two-Component System, Encoded by the s co5282/ sco5283 Genes, Affects Streptomyces coelicolor Morphology in Liquid Culture. Front Microbiol 2019; 10:1568. [PMID: 31354667 PMCID: PMC6629963 DOI: 10.3389/fmicb.2019.01568] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/24/2019] [Indexed: 01/23/2023] Open
Abstract
Streptomyces are mycelial bacteria adapted to grow in soil. They have become important producers of biomolecules with medical applications, but their growth in industrial fermenters is challenged by their peculiar morphology in liquid culture: the hyphae tend to clump and grow as large pellets, which are oxygen- and nutrient-limited, grow slowly and present diminished protein production. Here, by implementing an experimental evolution strategy, a S. coelicolor strain, 2L12, with dispersed morphology and reduced pellet size in liquid culture and no defects in either differentiation or secondary metabolism was selected. Genome sequencing revealed a single amino acid substitution in a sensor kinase, Sco5282, of unknown function to be responsible for the morphological changes. Moreover, genetic and biochemical scrutiny identified Sco5283 as the cognate response regulator and demonstrated that the acquired mutation activates this two-component system. Finally, transcriptomic analysis of the mutant strain revealed changes in expression of genes involved in central processes such as glycolysis, gluconeogenesis, stress-signaling pathways, proteins secretion and cell envelope metabolism. Thus a novel two-component system is proposed to play a key role in the control of Streptomyces extracellular metabolism.
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Affiliation(s)
- Erick Eligio Arroyo-Pérez
- Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gabriela González-Cerón
- Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gloria Soberón-Chávez
- Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Dimitris Georgellis
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Luis Servín-González
- Instituto de Investigaciones Biomédicas, Departamento de Biología Molecular y Biotecnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
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71
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Liu X, Zheng G, Wang G, Jiang W, Li L, Lu Y. Overexpression of the diguanylate cyclase CdgD blocks developmental transitions and antibiotic biosynthesis in Streptomyces coelicolor. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1492-1505. [PMID: 31228045 DOI: 10.1007/s11427-019-9549-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/24/2019] [Indexed: 11/24/2022]
Abstract
Cyclic dimeric GMP (c-di-GMP) has emerged as the nucleotide second messenger regulating both development and antibiotic production in high-GC, Gram-positive streptomycetes. Here, a diguanylate cyclase (DGC), CdgD, encoded by SCO5345 from the model strain Streptomyces coelicolor, was functionally identified and characterized to be involved in c-di-GMP synthesis through genetic and biochemical analysis. cdgD overexpression resulted in significantly reduced production of actinorhodin and undecylprodigiosin, as well as completely blocked sporulation or aerial mycelium formation on two different solid media. In the cdgD-overexpression strain, intracellular c-di-GMP levels were 13-27-fold higher than those in the wild-type strain. In vitro enzymatic assay demonstrated that CdgD acts as a DGC, which could efficiently catalyze the synthesis of c-di-GMP from two GTP molecules. Heterologous overproduction of cdgD in two industrial Streptomyces strains could similarly impair developmental transitions as well as antibiotic biosynthesis. Collectively, our results combined with previously reported data clearly demonstrated that c-di-GMP-mediated signalling pathway plays a central and universal role in the life cycle as well as secondary metabolism in streptomycetes.
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Affiliation(s)
- Xiaocao Liu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.,School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Guosong Zheng
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Gang Wang
- School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Weihong Jiang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.,Jiangsu National Synergetic Innovation Center for Advanced Materials, SICAM, Nanjing, 210009, China
| | - Lei Li
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China.
| | - Yinhua Lu
- School of Life Sciences, Shanghai Normal University, Shanghai, 200232, China.
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McLean TC, Wilkinson B, Hutchings MI, Devine R. Dissolution of the Disparate: Co-ordinate Regulation in Antibiotic Biosynthesis. Antibiotics (Basel) 2019; 8:E83. [PMID: 31216724 PMCID: PMC6627628 DOI: 10.3390/antibiotics8020083] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/10/2019] [Accepted: 06/14/2019] [Indexed: 12/25/2022] Open
Abstract
Discovering new antibiotics is vital to combat the growing threat of antimicrobial resistance. Most currently used antibiotics originate from the natural products of actinomycete bacteria, particularly Streptomyces species, that were discovered over 60 years ago. However, genome sequencing has revealed that most antibiotic-producing microorganisms encode many more natural products than previously thought. Biosynthesis of these natural products is tightly regulated by global and cluster situated regulators (CSRs), most of which respond to unknown environmental stimuli, and this likely explains why many biosynthetic gene clusters (BGCs) are not expressed under laboratory conditions. One approach towards novel natural product discovery is to awaken these cryptic BGCs by re-wiring the regulatory control mechanism(s). Most CSRs bind intergenic regions of DNA in their own BGC to control compound biosynthesis, but some CSRs can control the biosynthesis of multiple natural products by binding to several different BGCs. These cross-cluster regulators present an opportunity for natural product discovery, as the expression of multiple BGCs can be affected through the manipulation of a single regulator. This review describes examples of these different mechanisms, including specific examples of cross-cluster regulation, and assesses the impact that this knowledge may have on the discovery of novel natural products.
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Affiliation(s)
- Thomas C McLean
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Rebecca Devine
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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73
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Highlights of Streptomyces genetics. Heredity (Edinb) 2019; 123:23-32. [PMID: 31189905 DOI: 10.1038/s41437-019-0196-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/06/2019] [Accepted: 02/06/2019] [Indexed: 02/06/2023] Open
Abstract
Sixty years ago, the actinomycetes, which include members of the genus Streptomyces, with their bacterial cellular dimensions but a mycelial growth habit like fungi, were generally regarded as a possible intermediate group, and virtually nothing was known about their genetics. We now know that they are bacteria, but with many original features. Their genome is linear with a unique mode of replication, not circular like those of nearly all other bacteria. They transfer their chromosome from donor to recipient by a conjugation mechanism, but this is radically different from the E. coli paradigm. They have twice as many genes as a typical rod-shaped bacterium like Escherichia coli or Bacillus subtilis, and the genome typically carries 20 or more gene clusters encoding the biosynthesis of antibiotics and other specialised metabolites, only a small proportion of which are expressed under typical laboratory screening conditions. This means that there is a vast number of potentially valuable compounds to be discovered when these 'sleeping' genes are activated. Streptomyces genetics has revolutionised natural product chemistry by facilitating the analysis of novel biosynthetic steps and has led to the ability to engineer novel biosynthetic pathways and hence 'unnatural natural products', with potential to generate lead compounds for use in the struggle to combat the rise of antimicrobial resistance.
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74
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Núñez-Montero K, Lamilla C, Abanto M, Maruyama F, Jorquera MA, Santos A, Martinez-Urtaza J, Barrientos L. Antarctic Streptomyces fildesensis So13.3 strain as a promising source for antimicrobials discovery. Sci Rep 2019; 9:7488. [PMID: 31097761 PMCID: PMC6522549 DOI: 10.1038/s41598-019-43960-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/01/2019] [Indexed: 12/29/2022] Open
Abstract
Antarctic have been suggested as an attractive source for antibiotics discovery and members of Streptomyces genus have historically been studied as natural producers of antimicrobial metabolites. Nonetheless, our knowledge on antibiotic-producing Streptomyces from Antarctic is very limited. In this study, the antimicrobial activity of organic extracts from Antarctic Streptomyces strains was evaluated by disk diffusion assays and minimum inhibitory concentration. The strain Streptomyces sp. So13.3 showed the greatest antibiotic activity (MIC = 15.6 μg/mL) against Gram-positive bacteria and growth reduction of Gram‒negative pathogens. The bioactive fraction in the crude extract was revealed by TLC‒bioautography at Rf = 0.78 with molecular weight between 148 and 624 m/z detected by LC-ESI-MS/MS. The strain So13.3 was taxonomically affiliated as Streptomyces fildesensis. Whole genome sequencing and analysis suggested a 9.47 Mb genome size with 42 predicted biosynthetic gene clusters (BGCs) and 56 putative clusters representing a 22% of total genome content. Interestingly, a large number of them (11 of 42 BGCs and 40 of 56 putative BGCs), did not show similarities with other known BGCs. Our results highlight the potential of the Antarctic Streptomyces strains as a promising source of novel antimicrobials, particularly the strain Streptomyces fildesensis So13.3, which first draft genome is reported in this work.
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Affiliation(s)
- Kattia Núñez-Montero
- Laboratorio de Biología Molecular Aplicada, Centro de Excelencia en Medicina Traslacional, Universidad de La Frontera, Temuco, Chile.,Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile.,Centro de Investigación en Biotecnología, Escuela de Biología, Instituto Tecnológico de Costa Rica, Cartago, Costa Rica
| | - Claudio Lamilla
- Laboratorio de Biología Molecular Aplicada, Centro de Excelencia en Medicina Traslacional, Universidad de La Frontera, Temuco, Chile.,Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile
| | - Michel Abanto
- Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile
| | - Fumito Maruyama
- Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile.,Department of Microbiology, Graduate School of Medicine, Kyoto University, Yoshida‒Konoe‒cho, Sakyo‒ku, Kyoto, Japan
| | - Milko A Jorquera
- Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile.,Laboratorio de Ecología Microbiana Aplicada, Departamento de Ciencias Químicas y Recursos Naturales, Universidad de La Frontera, Temuco, Chile
| | - Andrés Santos
- Laboratorio de Biología Molecular Aplicada, Centro de Excelencia en Medicina Traslacional, Universidad de La Frontera, Temuco, Chile.,Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile.,Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth, Dorset, DT4 8UB, UK
| | - Jaime Martinez-Urtaza
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth, Dorset, DT4 8UB, UK
| | - Leticia Barrientos
- Laboratorio de Biología Molecular Aplicada, Centro de Excelencia en Medicina Traslacional, Universidad de La Frontera, Temuco, Chile. .,Núcleo Científico y Tecnológico en Biorecursos (BIOREN), Universidad de La Frontera, Temuco, Chile.
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75
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Tran NT, Huang X, Hong HJ, Bush MJ, Chandra G, Pinto D, Bibb MJ, Hutchings MI, Mascher T, Buttner MJ. Defining the regulon of genes controlled by σ E , a key regulator of the cell envelope stress response in Streptomyces coelicolor. Mol Microbiol 2019; 112:461-481. [PMID: 30907454 PMCID: PMC6767563 DOI: 10.1111/mmi.14250] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2019] [Indexed: 01/01/2023]
Abstract
The extracytoplasmic function (ECF) σ factor, σE , is a key regulator of the cell envelope stress response in Streptomyces coelicolor. Although its role in maintaining cell wall integrity has been known for over a decade, a comprehensive analysis of the genes under its control has not been undertaken. Here, using a combination of chromatin immunoprecipitation-sequencing (ChIP-seq), microarray transcriptional profiling and bioinformatic analysis, we attempt to define the σE regulon. Approximately half of the genes identified encode proteins implicated in cell envelope function. Seventeen novel targets were validated by S1 nuclease mapping or in vitro transcription, establishing a σE -binding consensus. Subsequently, we used bioinformatic analysis to look for conservation of the σE target promoters identified in S. coelicolor across 19 Streptomyces species. Key proteins under σE control across the genus include the actin homolog MreB, three penicillin-binding proteins, two L,D-transpeptidases, a LytR-CpsA-Psr-family protein predicted to be involved in cell wall teichoic acid deposition and a predicted MprF protein, which adds lysyl groups to phosphatidylglycerol to neutralize membrane surface charge. Taken together, these analyses provide biological insight into the σE -mediated cell envelope stress response in the genus Streptomyces.
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Affiliation(s)
- Ngat T Tran
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Xiaoluo Huang
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.,Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Hee-Jeon Hong
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Daniela Pinto
- Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Maureen J Bibb
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Thorsten Mascher
- Department Biology I, Ludwig-Maximilians-Universität München, Großhaderner Str. 2-4, Planegg-Martinsried, 82152, Germany
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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76
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Pfiffer V, Sarenko O, Possling A, Hengge R. Genetic dissection of Escherichia coli's master diguanylate cyclase DgcE: Role of the N-terminal MASE1 domain and direct signal input from a GTPase partner system. PLoS Genet 2019; 15:e1008059. [PMID: 31022167 PMCID: PMC6510439 DOI: 10.1371/journal.pgen.1008059] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/10/2019] [Accepted: 02/28/2019] [Indexed: 11/18/2022] Open
Abstract
The ubiquitous second messenger c-di-GMP promotes bacterial biofilm formation by playing diverse roles in the underlying regulatory networks. This is reflected in the multiplicity of diguanylate cyclases (DGC) and phosphodiesterases (PDE) that synthesize and degrade c-di-GMP, respectively, in most bacterial species. One of the 12 DGCs of Escherichia coli, DgcE, serves as the top-level trigger for extracellular matrix production during macrocolony biofilm formation. Its multi-domain architecture–a N-terminal membrane-inserted MASE1 domain followed by three PAS, a GGDEF and a degenerate EAL domain–suggested complex signal integration and transmission through DgcE. Genetic dissection of DgcE revealed activating roles for the MASE1 domain and the dimerization-proficient PAS3 region, whereas the inhibitory EALdeg domain counteracts the formation of DgcE oligomers. The MASE1 domain is directly targeted by the GTPase RdcA (YjdA), a dimer or oligomer that together with its partner protein RdcB (YjcZ) activates DgcE, probably by aligning and promoting dimerization of the PAS3 and GGDEF domains. This activation and RdcA/DgcE interaction depend on GTP hydrolysis by RdcA, suggesting GTP as an inhibitor and the pronounced decrease of the cellular GTP pool during entry into stationary phase, which correlates with DgcE-dependent activation of matrix production, as a possible input signal sensed by RdcA. Furthermore, DgcE exhibits rapid, continuous and processive proteolytic turnover that also depends on the relatively disordered transmembrane MASE1 domain. Overall, our study reveals a novel GTP/c-di-GMP-connecting signaling pathway through the multi-domain DGC DgcE with a dual role for the previously uncharacterized MASE1 signaling domain. Biofilms represent a multicellular life form of bacteria, in which large numbers of cells live in communities surrounded and protected by a self-generated extracellular polymeric matrix. As biofilms tolerate antibiotics and host immune systems, they are causally associated with chronic infections. Biofilm formation is generally promoted by the ubiquitous bacterial second messenger c-di-GMP. DgcE, one of the 12 diguanylate cyclases that produce c-di-GMP in E. coli, was previously shown to specifically act as a top level trigger in the regulatory network that drives biofilm matrix production in this bacterium. However, signal input into DgcE itself, which is a large six-domain protein, had remained unknown. Here we demonstrate that DgcE activity is controlled by a novel type of dynamin-like GTPase that directly interacts with the N-terminal membrane-intrinsic MASE1 domain of DgcE. Our finding of a dual function of this MASE1 domain, which is essential for both activation and continuous proteolysis of DgcE, is the first characterization of this widespread bacterial signaling domain. Signal input via the dynamin-like GTPase system suggests that c-di-GMP production by DgcE might be stimulated by the decreasing cellular GTP level during entry into stationary phase, which is precisely the time when biofilm matrix production is turned on.
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Affiliation(s)
- Vanessa Pfiffer
- Institut für Biologie / Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Olga Sarenko
- Institut für Biologie / Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Alexandra Possling
- Institut für Biologie / Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Regine Hengge
- Institut für Biologie / Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
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77
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Popp PF, Mascher T. Coordinated Cell Death in Isogenic Bacterial Populations: Sacrificing Some for the Benefit of Many? J Mol Biol 2019; 431:4656-4669. [PMID: 31029705 DOI: 10.1016/j.jmb.2019.04.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/11/2019] [Accepted: 04/14/2019] [Indexed: 01/22/2023]
Abstract
Antibiotics are classically perceived as biological weapons that bacteria produce to hold their ground against competing species in their natural habitat. But in the context of multicellular differentiation processes, antimicrobial compounds sometimes also play a role in intraspecies competition, resulting in the death of a sub-population of genetically identical siblings for the benefit of the population. Such a strategy is based on the diversification and hence phenotypic heterogeneity of an isogenic bacterial population. This review article will address three such phenomena. In Bacillus subtilis, cannibalism is a differentiation strategy that enhances biofilm formation, prolongs or potentially even prevents full commitment to endospore formation under starvation conditions, and protects cells within the biofilm against competing species. The nutrients released by lysed cells can be used by the toxin producers, thereby delaying the full activation of the master regulator of sporulation. A related strategy is associated with the initiation of competence development under nutrient excess in Streptococcus pneumoniae. This process, termed fratricide, causes allolysis in a sub-population and is thought to enhance genetic diversity within the species. In Myxococcus xanthus, a large fraction of the population undergoes programmed cell death during the formation of fruiting bodies. This sacrifice ensures the survival of the sporulating sub-population by providing nutrients and hence energy to complete this differentiation process. The biological relevance and underlying regulatory mechanisms of these three processes will be discussed in order to extract common features of such strategies. Moreover, open questions and future challenges will be addressed.
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Affiliation(s)
- Philipp F Popp
- Institute of Microbiology, Technische Universität (TU) Dresden, 01062 Dresden, Germany
| | - Thorsten Mascher
- Institute of Microbiology, Technische Universität (TU) Dresden, 01062 Dresden, Germany.
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78
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Saha S, Patra P, Igoshin O, Kroos L. Systematic analysis of the Myxococcus xanthus developmental gene regulatory network supports posttranslational regulation of FruA by C-signaling. Mol Microbiol 2019; 111:1732-1752. [PMID: 30895656 DOI: 10.1111/mmi.14249] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2019] [Indexed: 12/11/2022]
Abstract
Upon starvation Myxococcus xanthus undergoes multicellular development. Rod-shaped cells move into mounds in which some cells differentiate into spores. Cells begin committing to sporulation at 24-30 h poststarvation, but the mechanisms governing commitment are unknown. FruA and MrpC are transcription factors that are necessary for commitment. They bind cooperatively to promoter regions and activate developmental gene transcription, including that of the dev operon. Leading up to and during the commitment period, dev mRNA increased in wild type, but not in a mutant defective in C-signaling, a short-range signaling interaction between cells that is also necessary for commitment. The C-signaling mutant exhibited ~20-fold less dev mRNA than wild type at 30 h poststarvation, despite a similar level of MrpC and only 2-fold less FruA. Boosting the FruA level twofold in the C-signaling mutant had little effect on the dev mRNA level, and dev mRNA was not less stable in the C-signaling mutant. Neither did high cooperativity of MrpC and FruA binding upstream of the dev promoter explain the data. Rather, our systematic experimental and computational analyses support a model in which C-signaling activates FruA at least ninefold posttranslationally in order to commit a cell to spore formation.
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Affiliation(s)
- Shreya Saha
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Pintu Patra
- Department of Bioengineering, Rice University, Houston, TX, 77030, USA
| | - Oleg Igoshin
- Department of Bioengineering, Rice University, Houston, TX, 77030, USA
| | - Lee Kroos
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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79
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A Novel AdpA Homologue Negatively Regulates Morphological Differentiation in Streptomyces xiamenensis 318. Appl Environ Microbiol 2019; 85:AEM.03107-18. [PMID: 30683747 DOI: 10.1128/aem.03107-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 01/23/2019] [Indexed: 11/20/2022] Open
Abstract
The pleiotropic transcriptional regulator AdpA positively controls morphological differentiation and regulates secondary metabolism in most Streptomyces species. Streptomyces xiamenensis 318 has a linear chromosome 5.96 Mb in size. How AdpA affects secondary metabolism and morphological differentiation in such a naturally minimized genomic background is unknown. Here, we demonstrated that AdpA Sx , an AdpA orthologue in S. xiamenensis, negatively regulates cell growth and sporulation and bidirectionally regulates the biosynthesis of xiamenmycin and polycyclic tetramate macrolactams (PTMs) in S. xiamenensis 318. Overexpression of the adpASx gene in S. xiamenensis 318 had negative effects on morphological differentiation and resulted in reduced transcription of putative ssgA, ftsZ, ftsH, amfC, whiB, wblA1, wblA2, wblE, and a gene encoding sporulation-associated protein (sxim_29740), whereas the transcription of putative bldD and bldA genes was upregulated. Overexpression of adpASx led to significantly enhanced production of xiamenmycin but had detrimental effects on the production of PTMs. As expected, the transcriptional level of the xim gene cluster was upregulated, whereas the PTM gene cluster was downregulated. Moreover, AdpA Sx negatively regulated the transcription of its own gene. Electrophoretic mobility shift assays revealed that AdpA Sx can bind the promoter regions of structural genes of both the xim and PTM gene clusters as well as to the promoter regions of genes potentially involved in the cell growth and differentiation of S. xiamenensis 318. We report that an AdpA homologue has negative effects on morphological differentiation in S. xiamenensis 318, a finding confirmed when AdpA Sx was introduced into the heterologous host Streptomyces lividans TK24.IMPORTANCE AdpA is a key regulator of secondary metabolism and morphological differentiation in Streptomyces species. However, AdpA had not been reported to negatively regulate morphological differentiation. Here, we characterized the regulatory role of AdpA Sx in Streptomyces xiamenensis 318, which has a naturally streamlined genome. In this strain, AdpA Sx negatively regulated cell growth and morphological differentiation by directly controlling genes associated with these functions. AdpA Sx also bidirectionally controlled the biosynthesis of xiamenmycin and PTMs by directly regulating their gene clusters rather than through other regulators. Our findings provide additional evidence for the versatility of AdpA in regulating morphological differentiation and secondary metabolism in Streptomyces.
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80
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BldC Delays Entry into Development To Produce a Sustained Period of Vegetative Growth in Streptomyces venezuelae. mBio 2019; 10:mBio.02812-18. [PMID: 30723132 PMCID: PMC6428758 DOI: 10.1128/mbio.02812-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Understanding the mechanisms that drive bacterial morphogenesis depends on the dissection of the regulatory networks that underpin the cell biological processes involved. Recently, Streptomyces venezuelae has emerged as an attractive model system for the study of morphological differentiation in Streptomyces. This has led to significant progress in identifying the genes controlled by the transcription factors that regulate aerial mycelium formation (Bld regulators) and sporulation (Whi regulators). Taking advantage of S. venezuelae, we used ChIP-seq coupled with RNA-seq to identify the genes directly under the control of BldC. Because S. venezuelae sporulates in liquid culture, the complete spore-to-spore life cycle can be examined using time-lapse microscopy, and we applied this technique to the bldC mutant. These combined approaches reveal BldC to be a member of an emerging class of Bld regulators that function principally to repress key sporulation genes, thereby extending vegetative growth and blocking the onset of morphological differentiation. Streptomycetes are filamentous bacteria that differentiate by producing spore-bearing reproductive structures called aerial hyphae. The transition from vegetative to reproductive growth is controlled by the bld (bald) loci, and mutations in bld genes prevent the formation of aerial hyphae, either by blocking entry into development (typically mutations in activators) or by inducing precocious sporulation in the vegetative mycelium (typically mutations in repressors). One of the bld genes, bldC, encodes a 68-residue DNA-binding protein related to the DNA-binding domain of MerR-family transcription factors. Recent work has shown that BldC binds DNA by a novel mechanism, but there is less insight into its impact on Streptomyces development. Here we used ChIP-seq coupled with RNA-seq to define the BldC regulon in the model species Streptomyces venezuelae, showing that BldC can function both as a repressor and as an activator of transcription. Using electron microscopy and time-lapse imaging, we show that bldC mutants are bald because they initiate development prematurely, bypassing the formation of aerial hyphae. This is consistent with the premature expression of BldC target genes encoding proteins with key roles in development (e.g., whiD, whiI, sigF), chromosome condensation and segregation (e.g., smeA-sffA, hupS), and sporulation-specific cell division (e.g., dynAB), suggesting that BldC-mediated repression is critical to maintain a sustained period of vegetative growth prior to sporulation. We discuss the possible significance of BldC as an evolutionary link between MerR family transcription factors and DNA architectural proteins.
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81
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Recent Advances and Current Trends in Nucleotide Second Messenger Signaling in Bacteria. J Mol Biol 2019; 431:908-927. [PMID: 30668970 DOI: 10.1016/j.jmb.2019.01.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/05/2019] [Accepted: 01/07/2019] [Indexed: 02/01/2023]
Abstract
The "International Symposium on Nucleotide Second Messenger Signaling in Bacteria" (September 30-October 3, 2018, Berlin), which was organized within the framework of DFG Priority Programme 1879 (www.spp1879.de), brought together 125 participants from 20 countries to discuss recent progress and future trends in this field. Even 50 years after its discovery, (p)ppGpp is venturing into exciting new fields, especially in gram-positive bacteria. After triggering the current renaissance in bacterial second messenger research, c-di-GMP is becoming ever more global with abounding new molecular mechanisms of action and physiological functions. The more recently discovered c-di-AMP is rapidly catching up and has now been found even in archaea, with its function in osmotic homeostasis being conserved across kingdom boundaries. Small modules associated with mobile genetic elements, which make and react to numerous novel mixed cyclic dinucleotides, seem to roam around rather freely in the bacterial world. Finally, many novel and old nucleotide molecules are still lurking around in search of a function. Across many talks it became apparent that (p)ppGpp, c-di-GMP and GTP/ATP can share and compete for binding sites (e.g., the Walker A motif in GTP/ATPases) with intriguing regulatory consequences, thus contributing to the emergent trend of systemwide networks that interconnect diverse signaling nucleotides. Overall, this inspiring conference made it clear that second messenger signaling is currently one of the most dynamic and exciting areas in microbial molecular biology and physiology, with major impacts ranging from microbial systems biology and ecology to infection biology.
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82
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Christen M, Kamischke C, Kulasekara HD, Olivas KC, Kulasekara BR, Christen B, Kline T, Miller SI. Identification of Small-Molecule Modulators of Diguanylate Cyclase by FRET-Based High-Throughput Screening. Chembiochem 2018; 20:394-407. [PMID: 30395379 DOI: 10.1002/cbic.201800593] [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: 10/04/2018] [Indexed: 12/20/2022]
Abstract
The bacterial second messenger cyclic diguanosine monophosphate (c-di-GMP) is a key regulator of cellular motility, the cell cycle, and biofilm formation with its resultant antibiotic tolerance, which can make chronic infections difficult to treat. Therefore, diguanylate cyclases, which regulate the spatiotemporal production of c-di-GMP, might be attractive drug targets for control of biofilm formation that is part of chronic infections. We present a FRET-based biochemical high-throughput screening approach coupled with detailed structure-activity studies to identify synthetic small-molecule modulators of the diguanylate cyclase DgcA from Caulobacter crescentus. We identified a set of seven small molecules that regulate DgcA enzymatic activity in the low-micromolar range. Subsequent structure-activity studies on selected scaffolds revealed a remarkable diversity of modulatory behavior, including slight chemical substitutions that reverse the effects from allosteric enzyme inhibition to activation. The compounds identified represent new chemotypes and are potentially developable into chemical genetic tools for the dissection of c-di-GMP signaling networks and alteration of c-di-GMP-associated phenotypes. In sum, our studies underline the importance of detailed mechanism-of-action studies for inhibitors of c-di-GMP signaling and demonstrate the complex interplay between synthetic small molecules and the regulatory mechanisms that control the activity of diguanylate cyclases.
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Affiliation(s)
- Matthias Christen
- Eidgenössische Technische Hochschule Zürich, Department of Biology, Auguste-Piccard-Hof 1, 8093, Zürich, Switzerland
| | - Cassandra Kamischke
- University of Washington, Department of Microbiology, 1959 NE Pacific St., Box 357710, Seattle, WA, 98195, USA
| | - Hemantha D Kulasekara
- University of Washington, Department of Microbiology, 1959 NE Pacific St., Box 357710, Seattle, WA, 98195, USA
| | - Kathleen C Olivas
- Seattle Genetics, Inc., 21823 30th Drive SE, Bothell, WA, 98021, USA
| | - Bridget R Kulasekara
- University of Washington, Department of Genome Sciences, 1959 NE Pacific St., Box 357710, Seattle, WA, 98195, USA
| | - Beat Christen
- Eidgenössische Technische Hochschule Zürich, Department of Biology, Otto-Stern-Weg-3, 8093, Zürich, Switzerland
| | - Toni Kline
- Sutro Biopharma, 310 Utah Avenue, Suite 150, San Francisco, CA, 94080, USA
| | - Samuel I Miller
- University of Washington, Department of Microbiology, 1959 NE Pacific St., Box 357710, Seattle, WA, 98195, USA
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83
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Bush MJ. The actinobacterial WhiB-like (Wbl) family of transcription factors. Mol Microbiol 2018; 110:663-676. [PMID: 30179278 PMCID: PMC6282962 DOI: 10.1111/mmi.14117] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023]
Abstract
The WhiB‐like (Wbl) family of proteins are exclusively found in Actinobacteria. Wbls have been shown to play key roles in virulence and antibiotic resistance in Mycobacteria and Corynebacteria, reflecting their importance during infection by the human pathogens Mycobacterium tuberculosis, Mycobacterium leprae and Corynebacterium diphtheriae. In the antibiotic‐producing Streptomyces, several Wbls have important roles in the regulation of morphological differentiation, including WhiB, a protein that controls the initiation of sporulation septation and the founding member of the Wbl family. In recent years, genome sequencing has revealed the prevalence of Wbl paralogues in species throughout the Actinobacteria. Wbl proteins are small (generally ~80–140 residues) and each contains four invariant cysteine residues that bind an O2‐ and NO‐sensitive [4Fe–4S] cluster, raising the question as to how they can maintain distinct cellular functions within a given species. Despite their discovery over 25 years ago, the Wbl protein family has largely remained enigmatic. Here I summarise recent research in Mycobacteria, Corynebacteria and Streptomyces that sheds light on the biochemical function of Wbls as transcription factors and as potential sensors of O2 and NO. I suggest that Wbl evolution has created diversity in protein–protein interactions, [4Fe–4S] cluster‐sensitivity and the ability to bind DNA.
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Affiliation(s)
- Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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84
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Al-Bassam MM, Haist J, Neumann SA, Lindenberg S, Tschowri N. Expression Patterns, Genomic Conservation and Input Into Developmental Regulation of the GGDEF/EAL/HD-GYP Domain Proteins in Streptomyces. Front Microbiol 2018; 9:2524. [PMID: 30405580 PMCID: PMC6205966 DOI: 10.3389/fmicb.2018.02524] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/03/2018] [Indexed: 11/13/2022] Open
Abstract
To proliferate, antibiotic-producing Streptomyces undergo a complex developmental transition from vegetative growth to the production of aerial hyphae and spores. This morphological switch is controlled by the signaling molecule cyclic bis-(3',5') di-guanosine-mono-phosphate (c-di-GMP) that binds to the master developmental regulator, BldD, leading to repression of key sporulation genes during vegetative growth. However, a systematical analysis of all the GGDEF/EAL/HD-GYP proteins that control c-di-GMP levels in Streptomyces is still lacking. Here, we have FLAG-tagged all 10 c-di-GMP turnover proteins in Streptomyces venezuelae and characterized their expression patterns throughout the life cycle, revealing that the diguanylate cyclase (DGC) CdgB and the phosphodiesterase (PDE) RmdB are the most abundant GGDEF/EAL proteins. Moreover, we have deleted all the genes coding for c-di-GMP turnover enzymes individually and analyzed morphogenesis of the mutants in macrocolonies. We show that the composite GGDEF-EAL protein CdgC is an active DGC and that deletion of the DGCs cdgB and cdgC enhance sporulation whereas deletion of the PDEs rmdA and rmdB delay development in S. venezuelae. By comparing the pan genome of 93 fully sequenced Streptomyces species we show that the DGCs CdgA, CdgB, and CdgC, and the PDE RmdB represent the most conserved c-di-GMP-signaling proteins in the genus Streptomyces.
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Affiliation(s)
- Mahmoud M Al-Bassam
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, San Diego, CA, United States
| | - Julian Haist
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sara Alina Neumann
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sandra Lindenberg
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Natalia Tschowri
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, Berlin, Germany
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85
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McLaughlin PT, Bhardwaj V, Feeley BE, Higgs PI. MrpC, a CRP/Fnr homolog, functions as a negative autoregulator during the
Myxococcus xanthus
multicellular developmental program. Mol Microbiol 2018; 109:245-261. [DOI: 10.1111/mmi.13982] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/05/2018] [Accepted: 05/05/2018] [Indexed: 02/06/2023]
Affiliation(s)
| | - Vidhi Bhardwaj
- Department of EcophysiologyMax Planck Institute for Terrestrial MicrobiologyMarburg Hesse Germany
| | - Brooke E. Feeley
- Department of Biological SciencesWayne State UniversityDetroit MI USA
| | - Penelope I. Higgs
- Department of Biological SciencesWayne State UniversityDetroit MI USA
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86
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Synthetic far-red light-mediated CRISPR-dCas9 device for inducing functional neuronal differentiation. Proc Natl Acad Sci U S A 2018; 115:E6722-E6730. [PMID: 29967137 PMCID: PMC6055150 DOI: 10.1073/pnas.1802448115] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have developed an optogenetic far-red light (FRL)-activated CRISPR-dCas9 system (FACE) that is orthogonal, fine-tunable, reversible, and has robust endogenous gene-activation profiles upon stimulation with FRL, with deep tissue penetration capacity, low brightness, short illumination time, and negligible phototoxicity. The FACE device is biocompatible and meets the criteria for safe medical application in humans, providing a robust differentiation strategy for mass production of functional neural cells from induced pluripotent stem cells simply by utilizing a beam of FRL. This optogenetic device has expanded the optogenetic toolkit for precise mammalian genome engineering in many areas of basic and translational research that require precise spatiotemporal control of cellular behavior, which may in turn boost the clinical progress of optogenetics-based precision therapy. The ability to control the activity of CRISPR-dCas9 with precise spatiotemporal resolution will enable tight genome regulation of user-defined endogenous genes for studying the dynamics of transcriptional regulation. Optogenetic devices with minimal phototoxicity and the capacity for deep tissue penetration are extremely useful for precise spatiotemporal control of cellular behavior and for future clinic translational research. Therefore, capitalizing on synthetic biology and optogenetic design principles, we engineered a far-red light (FRL)-activated CRISPR-dCas9 effector (FACE) device that induces transcription of exogenous or endogenous genes in the presence of FRL stimulation. This versatile system provides a robust and convenient method for precise spatiotemporal control of endogenous gene expression and also has been demonstrated to mediate targeted epigenetic modulation, which can be utilized to efficiently promote differentiation of induced pluripotent stem cells into functional neurons by up-regulating a single neural transcription factor, NEUROG2. This FACE system might facilitate genetic/epigenetic reprogramming in basic biological research and regenerative medicine for future biomedical applications.
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87
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The MerR-like protein BldC binds DNA direct repeats as cooperative multimers to regulate Streptomyces development. Nat Commun 2018; 9:1139. [PMID: 29556010 PMCID: PMC5859096 DOI: 10.1038/s41467-018-03576-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/22/2018] [Indexed: 01/18/2023] Open
Abstract
Streptomycetes are notable for their complex life cycle and production of most clinically important antibiotics. A key factor that controls entry into development and the onset of antibiotic production is the 68-residue protein, BldC. BldC is a putative DNA-binding protein related to MerR regulators, but lacks coiled-coil dimerization and effector-binding domains characteristic of classical MerR proteins. Hence, the molecular function of the protein has been unclear. Here we show that BldC is indeed a DNA-binding protein and controls a regulon that includes other key developmental regulators. Intriguingly, BldC DNA-binding sites vary significantly in length. Our BldC-DNA structures explain this DNA-binding capability by revealing that BldC utilizes a DNA-binding mode distinct from MerR and other known regulators, involving asymmetric head-to-tail oligomerization on DNA direct repeats that results in dramatic DNA distortion. Notably, BldC-like proteins radiate throughout eubacteria, establishing BldC as the founding member of a new structural family of regulators. BldC regulates the onset of differentiation in Streptomycetes by a yet unknown molecular mechanism. Using a combination of structural, biochemical and in vivo approaches, the authors show that BldC controls the transcription of several developmental regulators and unravel its DNA binding mode.
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88
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Sun D, Liu C, Zhu J, Liu W. Connecting Metabolic Pathways: Sigma Factors in Streptomyces spp. Front Microbiol 2017; 8:2546. [PMID: 29312231 PMCID: PMC5742136 DOI: 10.3389/fmicb.2017.02546] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/07/2017] [Indexed: 11/13/2022] Open
Abstract
The gram-positive filamentous bacterium Streptomyces is one of the largest resources for bioactive metabolites, particularly antibiotics. Antibiotic production and other metabolic processes are tightly regulated at the transcriptional level. Sigma (σ) factors are components of bacterial RNA polymerases that determine promoter specificity. In Streptomyces, σ factors also play essential roles in signal transduction and in regulatory networks, thereby assisting in their survival in complex environments. However, our current understanding of σ factors in Streptomyces is still limited. In this mini-review, we demonstrate the roles of Streptomyces σ factors, illustrating that these serve as linkers of different metabolic pathways. Further investigations on σ factors may improve our knowledge of Streptomyces physiology and benefit exploitation of Streptomyces resources.
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Affiliation(s)
- Di Sun
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Cong Liu
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Jingrong Zhu
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Weijie Liu
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
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89
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Naylor D, DeGraaf S, Purdom E, Coleman-Derr D. Drought and host selection influence bacterial community dynamics in the grass root microbiome. THE ISME JOURNAL 2017; 11:2691-2704. [PMID: 28753209 PMCID: PMC5702725 DOI: 10.1038/ismej.2017.118] [Citation(s) in RCA: 267] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 04/20/2017] [Accepted: 06/07/2017] [Indexed: 12/30/2022]
Abstract
Root endophytes have been shown to have important roles in determining host fitness under periods of drought stress, and yet the effect of drought on the broader root endosphere bacterial community remains largely uncharacterized. In this study, we present phylogenetic profiles of bacterial communities associated with drought-treated root and rhizosphere tissues of 18 species of plants with varying degrees of drought tolerance belonging to the Poaceae family, including important crop plants. Through 16S rRNA gene profiling across two distinct watering regimes and two developmental time points, we demonstrate that there is a strong correlation between host phylogenetic distance and the microbiome dissimilarity within root tissues, and that drought weakens this correlation by inducing conserved shifts in bacterial community composition. We identify a significant enrichment in a wide variety of Actinobacteria during drought within the roots of all hosts, and demonstrate that this enrichment is higher within the root than it is in the surrounding environments. Furthermore, we show that this observed enrichment is the result of an absolute increase in Actinobacterial abundance and that previously hypothesized mechanisms for observed enrichments in Actinobacteria in drought-treated soils are unlikely to fully account for the phenomena observed here within the plant root.
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Affiliation(s)
- Dan Naylor
- Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkeley, CA, USA
- Plant Gene Expression Center, UC Berkeley, USDA-ARS, Albany, CA, USA
| | - Stephanie DeGraaf
- Department of Statistics, University of California, Berkeley, CA, USA
| | - Elizabeth Purdom
- Department of Statistics, University of California, Berkeley, CA, USA
| | - Devin Coleman-Derr
- Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkeley, CA, USA
- Plant Gene Expression Center, UC Berkeley, USDA-ARS, Albany, CA, USA
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90
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Hengge R. Trigger phosphodiesterases as a novel class of c-di-GMP effector proteins. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0498. [PMID: 27672149 PMCID: PMC5052742 DOI: 10.1098/rstb.2015.0498] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2016] [Indexed: 11/28/2022] Open
Abstract
The bacterial second messenger c-di-GMP controls bacterial biofilm formation, motility, cell cycle progression, development and virulence. It is synthesized by diguanylate cyclases (with GGDEF domains), degraded by specific phosphodiesterases (PDEs, with EAL of HD-GYP domains) and sensed by a wide variety of c-di-GMP-binding effectors that control diverse targets. c-di-GMP-binding effectors can be riboswitches as well as proteins with highly diverse structures and functions. The latter include ‘degenerate’ GGDEF/EAL domain proteins that are enzymatically inactive but still able to bind c-di-GMP. Surprisingly, two enzymatically active ‘trigger PDEs’, the Escherichia coli proteins PdeR and PdeL, have recently been added to this list of c-di-GMP-sensing effectors. Mechanistically, trigger PDEs are multifunctional. They directly and specifically interact with a macromolecular target (e.g. with a transcription factor or directly with a promoter region), whose activity they control by their binding and degradation of c-di-GMP—their PDE activity thus represents the c-di-GMP sensor or effector function. In this process, c-di-GMP serves as a regulatory ligand, but in contrast to classical allosteric control, this ligand is also degraded. The resulting kinetics and circuitry of control are ideally suited for trigger PDEs to serve as key components in regulatory switches. This article is part of the themed issue ‘The new bacteriology’.
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Affiliation(s)
- Regine Hengge
- Institute of Biology/Microbiology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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91
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Bobek J, Šmídová K, Čihák M. A Waking Review: Old and Novel Insights into the Spore Germination in Streptomyces. Front Microbiol 2017; 8:2205. [PMID: 29180988 PMCID: PMC5693915 DOI: 10.3389/fmicb.2017.02205] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/26/2017] [Indexed: 01/02/2023] Open
Abstract
The complex development undergone by Streptomyces encompasses transitions from vegetative mycelial forms to reproductive aerial hyphae that differentiate into chains of single-celled spores. Whereas their mycelial life – connected with spore formation and antibiotic production – is deeply investigated, spore germination as the counterpoint in their life cycle has received much less attention. Still, germination represents a system of transformation from metabolic zero point to a new living lap. There are several aspects of germination that may attract our attention: (1) Dormant spores are strikingly well-prepared for the future metabolic restart; they possess stable transcriptome, hydrolytic enzymes, chaperones, and other required macromolecules stabilized in a trehalose milieu; (2) Germination itself is a specific sequence of events leading to a complete morphological remodeling that include spore swelling, cell wall reconstruction, and eventually germ tube emergences; (3) Still not fully unveiled are the strategies that enable the process, including a single cell’s signal transduction and gene expression control, as well as intercellular communication and the probability of germination across the whole population. This review summarizes our current knowledge about the germination process in Streptomyces, while focusing on the aforementioned points.
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Affiliation(s)
- Jan Bobek
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czechia.,Chemistry Department, Faculty of Science, Jan Evangelista Purkyně University in Ústí nad Labem, Ústí nad Labem, Czechia.,Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Klára Šmídová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czechia.,Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Matouš Čihák
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czechia
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92
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Schumacher MA, Zeng W, Findlay KC, Buttner MJ, Brennan RG, Tschowri N. The Streptomyces master regulator BldD binds c-di-GMP sequentially to create a functional BldD2-(c-di-GMP)4 complex. Nucleic Acids Res 2017; 45:6923-6933. [PMID: 28449057 PMCID: PMC5499655 DOI: 10.1093/nar/gkx287] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/12/2017] [Indexed: 01/05/2023] Open
Abstract
Streptomyces are ubiquitous soil bacteria that undergo a complex developmental transition coinciding with their production of antibiotics. This transition is controlled by binding of a novel tetrameric form of the second messenger, 3΄-5΄ cyclic diguanylic acid (c-di-GMP) to the master repressor, BldD. In all domains of life, nucleotide-based second messengers allow a rapid integration of external and internal signals into regulatory pathways that control cellular responses to changing conditions. c-di-GMP can assume alternative oligomeric states to effect different functions, binding to effector proteins as monomers, intercalated dimers or, uniquely in the case of BldD, as a tetramer. However, at physiological concentrations c-di-GMP is a monomer and little is known about how higher oligomeric complexes assemble on effector proteins and if intermediates in assembly pathways have regulatory significance. Here, we show that c-di-GMP binds BldD using an ordered, sequential mechanism and that BldD function necessitates the assembly of the BldD2-(c-di-GMP)4 complex.
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Affiliation(s)
- Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Wenjie Zeng
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Kim C Findlay
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Mark J Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27701, USA
| | - Natalia Tschowri
- Institut für Biologie/Mikrobiologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
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93
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Zhang P, Wu L, Zhu Y, Liu M, Wang Y, Cao G, Chen XL, Tao M, Pang X. Deletion of MtrA Inhibits Cellular Development of Streptomyces coelicolor and Alters Expression of Developmental Regulatory Genes. Front Microbiol 2017; 8:2013. [PMID: 29085353 PMCID: PMC5650626 DOI: 10.3389/fmicb.2017.02013] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 09/29/2017] [Indexed: 11/18/2022] Open
Abstract
The developmental life cycle of Streptomyces species includes aerial hyphae formation and spore maturation, two distinct developmental processes that are controlled, respectively, by two families of developmental regulatory genes, bld and whi. In this study, we show that the response regulator MtrA (SCO3013) is critical for normal development of aerial hyphae in S. coelicolor and related species. ΔmtrA, a deletion mutant of the response regulator gene mtrA, exhibited the bald phenotype typical of bld mutants defective in aerial mycelium formation, with formation either much delayed or absent depending on the culture medium. Transcriptional analysis indicated that MtrA activates multiple genes involved in formation of aerial mycelium, including chp, rdl, and ram genes, as well as developmental regulatory genes of the bld and whi families. However, the major regulatory gene bldD showed enhanced expression in ΔmtrA, suggesting it is repressed by MtrA. electrophoretic mobility shift assays indicated that MtrA binds upstream of several genes with altered expression in ΔmtrA, including bldD and whiI, and sequences similar to the consensus binding sequence for MtrA of another actinomycete, Mycobacterium tuberculosis, were found in the bound sites. A loosely conserved recognition sequence containing two short, direct repeats was identified for MtrA of S. coelicolor and was validated using mutational analysis. MtrA homologs are widely distributed among Streptomyces species, and as with S. coelicolor, deletion of the mtrA homologs sve_2757 from S. venezuelae and sli_3357 from S. lividans resulted in conditional bald morphology. Our study suggests a critical and conserved role for MtrA in Streptomyces development.
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Affiliation(s)
- Peipei Zhang
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Lili Wu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Yanping Zhu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Meng Liu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Yemin Wang
- The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Guangxiang Cao
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Xiu-Lan Chen
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Meifeng Tao
- The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Xiuhua Pang
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
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94
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Bartholomae M, Buivydas A, Viel JH, Montalbán-López M, Kuipers OP. Major gene-regulatory mechanisms operating in ribosomally synthesized and post-translationally modified peptide (RiPP) biosynthesis. Mol Microbiol 2017; 106:186-206. [DOI: 10.1111/mmi.13764] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Maike Bartholomae
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Andrius Buivydas
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Jakob H. Viel
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Manuel Montalbán-López
- Department of Microbiology; University of Granada, C. Fuentenueva s/n; 18071 Granada Spain
| | - Oscar P. Kuipers
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
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95
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A Novel Two-Component System, GluR-GluK, Involved in Glutamate Sensing and Uptake in Streptomyces coelicolor. J Bacteriol 2017; 199:JB.00097-17. [PMID: 28461451 DOI: 10.1128/jb.00097-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/24/2017] [Indexed: 11/20/2022] Open
Abstract
Two-component systems (TCSs), the predominant signal transduction pathways employed by bacteria, play important roles in physiological metabolism in Streptomyces Here, a novel TCS, GluR-GluK (encoded by SCO5778-SCO5779), which is located divergently from the gluABCD operon encoding a glutamate uptake system, was identified as being involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Streptomyces coelicolor Under the condition of minimal medium (MM) supplemented with different concentrations of glutamate, deletion of the gluR-gluK operon (gluR-K) resulted in enhanced actinorhodin (ACT) but reduced undecylprodigiosin (RED) and yellow type I polyketide (yCPK) production, suggesting that GluR-GluK plays a differential role in antibiotic biosynthesis. Furthermore, we found that the response regulator GluR directly promotes the expression of gluABCD under the culture condition of MM with a high concentration of glutamate (75 mM). Using the biolayer interferometry assay, we demonstrated that glutamate acts as the direct signal of the histidine kinase GluK. It was therefore suggested that upon sensing high concentrations of glutamate, GluR-GluK would be activated and thereby facilitate glutamate uptake by increasing gluABCD expression. Finally, we demonstrated that the role of GluR-GluK in antibiotic biosynthesis is independent of its function in glutamate uptake. Considering the wide distribution of the glutamate-sensing (GluR-GluK) and uptake (GluABCD) module in actinobacteria, it could be concluded that the GluR-GluK signal transduction pathway involved in secondary metabolism and glutamate uptake should be highly conserved in this bacterial phylum.IMPORTANCE In this study, a novel two-component system (TCS), GluR-GluK, was identified to be involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Streptomyces coelicolor A possible GluR-GluK working model was proposed. Upon sensing high glutamate concentrations (such as 75 mM), activated GluR-GluK could regulate both glutamate uptake and antibiotic biosynthesis. However, under a culture condition of MM supplemented with low concentrations of glutamate (such as 10 mM), although GluR-GluK is activated, its activity is sufficient only for the regulation of antibiotic biosynthesis. To the best of our knowledge, this is the first report describing a TCS signal transduction pathway for glutamate sensing and uptake in actinobacteria.
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96
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Two dynamin-like proteins stabilize FtsZ rings during Streptomyces sporulation. Proc Natl Acad Sci U S A 2017; 114:E6176-E6183. [PMID: 28687675 DOI: 10.1073/pnas.1704612114] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During sporulation, the filamentous bacteria Streptomyces undergo a massive cell division event in which the synthesis of ladders of sporulation septa convert multigenomic hyphae into chains of unigenomic spores. This process requires cytokinetic Z-rings formed by the bacterial tubulin homolog FtsZ, and the stabilization of the newly formed Z-rings is crucial for completion of septum synthesis. Here we show that two dynamin-like proteins, DynA and DynB, play critical roles in this process. Dynamins are a family of large, multidomain GTPases involved in key cellular processes in eukaryotes, including vesicle trafficking and organelle division. Many bacterial genomes encode dynamin-like proteins, but the biological function of these proteins has remained largely enigmatic. Using a cell biological approach, we show that the two Streptomyces dynamins specifically localize to sporulation septa in an FtsZ-dependent manner. Moreover, dynamin mutants have a cell division defect due to the decreased stability of sporulation-specific Z-rings, as demonstrated by kymographs derived from time-lapse images of FtsZ ladder formation. This defect causes the premature disassembly of individual Z-rings, leading to the frequent abortion of septum synthesis, which in turn results in the production of long spore-like compartments with multiple chromosomes. Two-hybrid analysis revealed that the dynamins are part of the cell division machinery and that they mediate their effects on Z-ring stability during developmentally controlled cell division via a network of protein-protein interactions involving DynA, DynB, FtsZ, SepF, SepF2, and the FtsZ-positioning protein SsgB.
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97
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Som NF, Heine D, Holmes NA, Munnoch JT, Chandra G, Seipke RF, Hoskisson PA, Wilkinson B, Hutchings MI. The Conserved Actinobacterial Two-Component System MtrAB Coordinates Chloramphenicol Production with Sporulation in Streptomyces venezuelae NRRL B-65442. Front Microbiol 2017; 8:1145. [PMID: 28702006 PMCID: PMC5487470 DOI: 10.3389/fmicb.2017.01145] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/06/2017] [Indexed: 12/30/2022] Open
Abstract
Streptomyces bacteria make numerous secondary metabolites, including half of all known antibiotics. Production of antibiotics is usually coordinated with the onset of sporulation but the cross regulation of these processes is not fully understood. This is important because most Streptomyces antibiotics are produced at low levels or not at all under laboratory conditions and this makes large scale production of these compounds very challenging. Here, we characterize the highly conserved actinobacterial two-component system MtrAB in the model organism Streptomyces venezuelae and provide evidence that it coordinates production of the antibiotic chloramphenicol with sporulation. MtrAB are known to coordinate DNA replication and cell division in Mycobacterium tuberculosis where TB-MtrA is essential for viability but MtrB is dispensable. We deleted mtrB in S. venezuelae and this resulted in a global shift in the metabolome, including constitutive, higher-level production of chloramphenicol. We found that chloramphenicol is detectable in the wild-type strain, but only at very low levels and only after it has sporulated. ChIP-seq showed that MtrA binds upstream of DNA replication and cell division genes and genes required for chloramphenicol production. dnaA, dnaN, oriC, and wblE (whiB1) are DNA binding targets for MtrA in both M. tuberculosis and S. venezuelae. Intriguingly, over-expression of TB-MtrA and gain of function TB- and Sv-MtrA proteins in S. venezuelae also switched on higher-level production of chloramphenicol. Given the conservation of MtrAB, these constructs might be useful tools for manipulating antibiotic production in other filamentous actinomycetes.
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Affiliation(s)
- Nicolle F. Som
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - Daniel Heine
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
| | - Neil A. Holmes
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - John T. Munnoch
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
| | - Govind Chandra
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
| | - Ryan F. Seipke
- School of Biological Sciences, University of East AngliaNorwich, United Kingdom
- School of Molecular and Cellular Biology, Astbury Centre for Structural Molecular Biology, University of LeedsLeeds, United Kingdom
| | - Paul A. Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of StrathclydeGlasgow, United Kingdom
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes CentreNorwich, United Kingdom
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98
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Electron-shuttling antibiotics structure bacterial communities by modulating cellular levels of c-di-GMP. Proc Natl Acad Sci U S A 2017; 114:E5236-E5245. [PMID: 28607054 DOI: 10.1073/pnas.1700264114] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Diverse organisms secrete redox-active antibiotics, which can be used as extracellular electron shuttles by resistant microbes. Shuttle-mediated metabolism can support survival when substrates are available not locally but rather at a distance. Such conditions arise in multicellular communities, where the formation of chemical gradients leads to resource limitation for cells at depth. In the pathogenic bacterium Pseudomonas aeruginosa PA14, antibiotics called phenazines act as oxidants to balance the intracellular redox state of cells in anoxic biofilm subzones. PA14 colony biofilms show a profound morphogenic response to phenazines resulting from electron acceptor-dependent inhibition of ECM production. This effect is reminiscent of the developmental responses of some eukaryotic systems to redox control, but for bacterial systems its mechanistic basis has not been well defined. Here, we identify the regulatory protein RmcA and show that it links redox conditions to PA14 colony morphogenesis by modulating levels of bis-(3',5')-cyclic-dimeric-guanosine (c-di-GMP), a second messenger that stimulates matrix production, in response to phenazine availability. RmcA contains four Per-Arnt-Sim (PAS) domains and domains with the potential to catalyze the synthesis and degradation of c-di-GMP. Our results suggest that phenazine production modulates RmcA activity such that the protein degrades c-di-GMP and thereby inhibits matrix production during oxidizing conditions. RmcA thus forms a mechanistic link between cellular redox sensing and community morphogenesis analogous to the functions performed by PAS-domain-containing regulatory proteins found in complex eukaryotes.
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99
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Regulation of Sporangium Formation by BldD in the Rare Actinomycete Actinoplanes missouriensis. J Bacteriol 2017; 199:JB.00840-16. [PMID: 28348024 DOI: 10.1128/jb.00840-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/19/2017] [Indexed: 11/20/2022] Open
Abstract
The rare actinomycete Actinoplanes missouriensis forms sporangia, including hundreds of flagellated spores that start swimming as zoospores after their release. Under conditions suitable for vegetative growth, zoospores stop swimming and germinate. A comparative proteome analysis between zoospores and germinating cells identified 15 proteins that were produced in larger amounts in germinating cells. They include an orthologue of BldD (herein named AmBldD [BldD of A. missouriensis]), which is a transcriptional regulator involved in morphological development and secondary metabolism in Streptomyces AmBldD was detected in mycelia during vegetative growth but was barely detected in mycelia during the sporangium-forming phase, in spite of the constant transcription of AmbldD throughout growth. An AmbldD mutant started to form sporangia much earlier than the wild-type strain, and the resulting sporangia were morphologically abnormal. Recombinant AmBldD bound a palindromic sequence, the AmBldD box, located upstream from AmbldD 3',5'-Cyclic di-GMP significantly enhanced the in vitro DNA-binding ability of AmBldD. A chromatin immunoprecipitation-sequencing analysis and an in silico search for AmBldD boxes revealed that AmBldD bound 346 genomic loci that contained the 19-bp inverted repeat 5'-NN(G/A)TNACN(C/G)N(G/C)NGTNA(C/T)NN-3' as the consensus AmBldD-binding sequence. The transcriptional analysis of 27 selected AmBldD target gene candidates indicated that AmBldD should repress 12 of the 27 genes, including bldM, ssgB, whiD, ddbA, and wblA orthologues. These genes are involved in morphological development in Streptomyces coelicolor A3(2). Thus, AmBldD is a global transcriptional regulator that seems to repress the transcription of tens of genes during vegetative growth, some of which are likely to be required for sporangium formation.IMPORTANCE The rare actinomycete Actinoplanes missouriensis undergoes complex morphological differentiation, including sporangium formation. However, almost no molecular biological studies have been conducted on this bacterium. BldD is a key global regulator involved in the morphological development of streptomycetes. BldD orthologues are highly conserved among sporulating actinomycetes, but no BldD orthologues, except one in Saccharopolyspora erythraea, have been studied outside the streptomycetes. Here, it was revealed that the BldD orthologue AmBldD is essential for normal developmental processes in A. missouriensis The AmBldD regulon seems to be different from the BldD regulon in Streptomyces coelicolor A3(2), but they share four genes that are involved in morphological differentiation in S. coelicolor A3(2).
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Abstract
The survival strategy of Actinoplanes is fascinating from an evolutionary perspective, combining a short motile phase in an otherwise nonmotile, filamentous life cycle and the somewhat paradoxical concept of spores-normally thought of as a resting stage-that swim. In the first paper to report a molecular genetic analysis of development in Actinoplanes, the authors identify a key regulator of the entry into development (Y. Mouri, K. Konishi, A. Fujita, T. Tezuka, Y. Ohnishi, J Bacteriol 199:e00840-16, 2017, https://doi.org/10.1128/JB.00840-16).
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