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Muñoz-Gutierrez V, Cornejo FA, Schmidt K, Frese CK, Halte M, Erhardt M, Elsholz AKW, Turgay K, Charpentier E. Bacillus subtilis remains translationally active after CRISPRi-mediated replication initiation arrest. mSystems 2024; 9:e0022124. [PMID: 38546227 PMCID: PMC11019786 DOI: 10.1128/msystems.00221-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 03/06/2024] [Indexed: 04/17/2024] Open
Abstract
Initiation of bacterial DNA replication takes place at the origin of replication (oriC), a region characterized by the presence of multiple DnaA boxes that serve as the binding sites for the master initiator protein DnaA. This process is tightly controlled by modulation of the availability or activity of DnaA and oriC during development or stress conditions. Here, we aimed to uncover the physiological and molecular consequences of stopping replication in the model bacterium Bacillus subtilis. We successfully arrested replication in B. subtilis by employing a clustered regularly interspaced short palindromic repeats interference (CRISPRi) approach to specifically target the key DnaA boxes 6 and 7, preventing DnaA binding to oriC. In this way, other functions of DnaA, such as a transcriptional regulator, were not significantly affected. When replication initiation was halted by this specific artificial and early blockage, we observed that non-replicating cells continued translation and cell growth, and the initial replication arrest did not induce global stress conditions such as the SOS response.IMPORTANCEAlthough bacteria constantly replicate under laboratory conditions, natural environments expose them to various stresses such as lack of nutrients, high salinity, and pH changes, which can trigger non-replicating states. These states can enable bacteria to (i) become tolerant to antibiotics (persisters), (ii) remain inactive in specific niches for an extended period (dormancy), and (iii) adjust to hostile environments. Non-replicating states have also been studied because of the possibility of repurposing energy for the production of additional metabolites or proteins. Using clustered regularly interspaced short palindromic repeats interference (CRISPRi) targeting bacterial replication initiation sequences, we were able to successfully control replication initiation in Bacillus subtilis. This precise approach makes it possible to study non-replicating phenotypes, contributing to a better understanding of bacterial adaptive strategies.
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Affiliation(s)
- Vanessa Muñoz-Gutierrez
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | | | - Katja Schmidt
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | | | - Manuel Halte
- Humboldt-Universität zu Berlin, Institute of Biology – Molecular Microbiology, Berlin, Germany
| | - Marc Erhardt
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Humboldt-Universität zu Berlin, Institute of Biology – Molecular Microbiology, Berlin, Germany
| | | | - Kürşad Turgay
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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2
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Bohorquez LC, de Sousa J, Garcia-Garcia T, Dugar G, Wang B, Jonker MJ, Noirot-Gros MF, Lalk M, Hamoen LW. Metabolic and chromosomal changes in a Bacillus subtilis whiA mutant. Microbiol Spectr 2023; 11:e0179523. [PMID: 37916812 PMCID: PMC10714963 DOI: 10.1128/spectrum.01795-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/10/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE WhiA is a conserved DNA-binding protein that influences cell division in many Gram-positive bacteria and, in B. subtilis, also chromosome segregation. How WhiA works in Bacillus subtilis is unknown. Here, we tested three hypothetical mechanisms using metabolomics, fatty acid analysis, and chromosome confirmation capture experiments. This revealed that WhiA does not influence cell division and chromosome segregation by modulating either central carbon metabolism or fatty acid composition. However, the inactivation of WhiA reduces short-range chromosome interactions. These findings provide new avenues to study the molecular mechanism of WhiA in the future.
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Affiliation(s)
- Laura C. Bohorquez
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Joana de Sousa
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Transito Garcia-Garcia
- Laboratoire de Genetique Microbienne, Domaine de Vilvert, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Gaurav Dugar
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Biwen Wang
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Martijs J. Jonker
- RNA Biology and Applied Bioinformatics Research Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Marie-Françoise Noirot-Gros
- Laboratoire de Genetique Microbienne, Domaine de Vilvert, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Michael Lalk
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Leendert W. Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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3
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Wang S, Chen X, Jin X, Gu F, Jiang W, Qi Q, Liang Q. Creating Polyploid Escherichia Coli and Its Application in Efficient L-Threonine Production. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302417. [PMID: 37749873 PMCID: PMC10625114 DOI: 10.1002/advs.202302417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/31/2023] [Indexed: 09/27/2023]
Abstract
Prokaryotic genomes are generally organized in haploid. In synthetic biological research, efficient chassis cells must be constructed to produce bio-based products. Here, the essential division of the ftsZ gene to create functional polyploid E. coli is regulated. The artificial polyploid E. coli containing 2-4 chromosomes is confirmed through PCR amplification, terminator localization, and flow cytometry. The polyploid E. coli exhibits a larger cell size, and its low pH tolerance and acetate resistance are stronger than those of haploid E. coli. Transcriptome analysis shows that the genes of the cell's main functional pathways are significantly upregulated in the polyploid E. coli. These advantages of the polyploid E. coli results in the highest reported L-threonine yield (160.3 g L-1 ) in fed-batch fermentation to date. In summary, an easy and convenient method for constructing polyploid E. coli and demonstrated its application in L-threonine production is developed. This work provides a new approach for creating an excellent host strain for biochemical production and studying the evolution of prokaryotes and their chromosome functions.
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Affiliation(s)
- Sumeng Wang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Xuanmu Chen
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Xin Jin
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Fei Gu
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Wei Jiang
- Research Center of Basic MedicineCentral Hospital Affiliated to Shandong First Medical UniversityJinan250013P. R. China
| | - Qingsheng Qi
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Quanfeng Liang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
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4
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Arjes HA, Sun J, Liu H, Nguyen TH, Culver RN, Celis AI, Walton SJ, Vasquez KS, Yu FB, Xue KS, Newton D, Zermeno R, Weglarz M, Deutschbauer A, Huang KC, Shiver AL. Construction and characterization of a genome-scale ordered mutant collection of Bacteroides thetaiotaomicron. BMC Biol 2022; 20:285. [PMID: 36527020 PMCID: PMC9758874 DOI: 10.1186/s12915-022-01481-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Ordered transposon-insertion collections, in which specific transposon-insertion mutants are stored as monocultures in a genome-scale collection, represent a promising tool for genetic dissection of human gut microbiota members. However, publicly available collections are scarce and the construction methodology remains in early stages of development. RESULTS Here, we describe the assembly of a genome-scale ordered collection of transposon-insertion mutants in the model gut anaerobe Bacteroides thetaiotaomicron VPI-5482 that we created as a resource for the research community. We used flow cytometry to sort single cells from a pooled library, located mutants within this initial progenitor collection by applying a pooling strategy with barcode sequencing, and re-arrayed specific mutants to create a condensed collection with single-insertion strains covering >2500 genes. To demonstrate the potential of the condensed collection for phenotypic screening, we analyzed growth dynamics and cell morphology. We identified both growth defects and altered cell shape in mutants disrupting sphingolipid synthesis and thiamine scavenging. Finally, we analyzed the process of assembling the B. theta condensed collection to identify inefficiencies that limited coverage. We demonstrate as part of this analysis that the process of assembling an ordered collection can be accurately modeled using barcode sequencing data. CONCLUSION We expect that utilization of this ordered collection will accelerate research into B. theta physiology and that lessons learned while assembling the collection will inform future efforts to assemble ordered mutant collections for an increasing number of gut microbiota members.
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Affiliation(s)
- Heidi A. Arjes
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Jiawei Sun
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Hualan Liu
- grid.184769.50000 0001 2231 4551Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Taylor H. Nguyen
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Rebecca N. Culver
- grid.168010.e0000000419368956Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Arianna I. Celis
- grid.168010.e0000000419368956Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Sophie Jean Walton
- grid.168010.e0000000419368956Biophysics Training Program, Stanford University School of Medicine, Stanford, CA USA
| | - Kimberly S. Vasquez
- grid.168010.e0000000419368956Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Feiqiao Brian Yu
- grid.499295.a0000 0004 9234 0175Chan Zuckerberg Biohub, San Francisco, CA 94158 USA
| | - Katherine S. Xue
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA ,grid.168010.e0000000419368956Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Daniel Newton
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA
| | - Ricardo Zermeno
- grid.168010.e0000000419368956Stanford Shared FACS Facility, Center for Molecular and Genetic Medicine, Stanford University, Stanford, CA USA
| | - Meredith Weglarz
- grid.168010.e0000000419368956Stanford Shared FACS Facility, Center for Molecular and Genetic Medicine, Stanford University, Stanford, CA USA
| | - Adam Deutschbauer
- grid.184769.50000 0001 2231 4551Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA USA ,grid.47840.3f0000 0001 2181 7878Department of Plant and Microbial Biology, University of California, Berkeley, CA USA
| | - Kerwyn Casey Huang
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA ,grid.168010.e0000000419368956Biophysics Training Program, Stanford University School of Medicine, Stanford, CA USA ,grid.168010.e0000000419368956Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305 USA ,grid.499295.a0000 0004 9234 0175Chan Zuckerberg Biohub, San Francisco, CA 94158 USA
| | - Anthony L. Shiver
- grid.168010.e0000000419368956Department of Bioengineering, Stanford University, Stanford, CA USA
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5
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Shinn MK, Cohan MC, Bullock JL, Ruff KM, Levin PA, Pappu RV. Connecting sequence features within the disordered C-terminal linker of Bacillus subtilis FtsZ to functions and bacterial cell division. Proc Natl Acad Sci U S A 2022; 119:e2211178119. [PMID: 36215496 PMCID: PMC9586301 DOI: 10.1073/pnas.2211178119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/20/2022] [Indexed: 11/21/2022] Open
Abstract
Intrinsically disordered regions (IDRs) can function as autoregulators of folded enzymes to which they are tethered. One example is the bacterial cell division protein FtsZ. This includes a folded core and a C-terminal tail (CTT) that encompasses a poorly conserved, disordered C-terminal linker (CTL) and a well-conserved 17-residue C-terminal peptide (CT17). Sites for GTPase activity of FtsZs are formed at the interface between GTP binding sites and T7 loops on cores of adjacent subunits within dimers. Here, we explore the basis of autoregulatory functions of the CTT in Bacillus subtilis FtsZ (Bs-FtsZ). Molecular simulations show that the CT17 of Bs-FtsZ makes statistically significant CTL-mediated contacts with the T7 loop. Statistical coupling analysis of more than 1,000 sequences from FtsZ orthologs reveals clear covariation of the T7 loop and the CT17 with most of the core domain, whereas the CTL is under independent selection. Despite this, we discover the conservation of nonrandom sequence patterns within CTLs across orthologs. To test how the nonrandom patterns of CTLs mediate CTT-core interactions and modulate FtsZ functionalities, we designed Bs-FtsZ variants by altering the patterning of oppositely charged residues within the CTL. Such alterations disrupt the core-CTT interactions, lead to anomalous assembly and inefficient GTP hydrolysis in vitro and protein degradation, aberrant assembly, and disruption of cell division in vivo. Our findings suggest that viable CTLs in FtsZs are likely to be IDRs that encompass nonrandom, functionally relevant sequence patterns that also preserve three-way covariation of the CT17, the T7 loop, and core domain.
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Affiliation(s)
- Min Kyung Shinn
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Megan C. Cohan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Jessie L. Bullock
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130
| | - Kiersten M. Ruff
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
| | - Petra A. Levin
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130
| | - Rohit V. Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130
- Center for Biomolecular Condensates, James McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO 63130
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6
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Wozniak KJ, Burby PE, Nandakumar J, Simmons LA. Structure and kinase activity of bacterial cell cycle regulator CcrZ. PLoS Genet 2022; 18:e1010196. [PMID: 35576203 PMCID: PMC9135335 DOI: 10.1371/journal.pgen.1010196] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 05/26/2022] [Accepted: 04/09/2022] [Indexed: 11/24/2022] Open
Abstract
CcrZ is a recently discovered cell cycle regulator that connects DNA replication initiation with cell division in pneumococci and may have a similar function in related bacteria. CcrZ is also annotated as a putative kinase, suggesting that CcrZ homologs could represent a novel family of bacterial kinase-dependent cell cycle regulators. Here, we investigate the CcrZ homolog in Bacillus subtilis and show that cells lacking ccrZ are sensitive to a broad range of DNA damage. We demonstrate that increased expression of ccrZ results in over-initiation of DNA replication. In addition, increased expression of CcrZ activates the DNA damage response. Using sensitivity to DNA damage as a proxy, we show that the negative regulator for replication initiation (yabA) and ccrZ function in the same pathway. We show that CcrZ interacts with replication initiation proteins DnaA and DnaB, further suggesting that CcrZ is important for replication timing. To understand how CcrZ functions, we solved the crystal structure bound to AMP-PNP to 2.6 Å resolution. The CcrZ structure most closely resembles choline kinases, consisting of a bilobal structure with a cleft between the two lobes for binding ATP and substrate. Inspection of the structure reveals a major restructuring of the substrate-binding site of CcrZ relative to the choline-binding pocket of choline kinases, consistent with our inability to detect activity with choline for this protein. Instead, CcrZ shows activity on D-ribose and 2-deoxy-D-ribose, indicating adaptation of the choline kinase fold in CcrZ to phosphorylate a novel substrate. We show that integrity of the kinase active site is required for ATPase activity in vitro and for function in vivo. This work provides structural, biochemical, and functional insight into a newly identified, and conserved group of bacterial kinases that regulate DNA replication initiation.
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Affiliation(s)
- Katherine J. Wozniak
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Peter E. Burby
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Lyle A. Simmons
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
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7
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Büke F, Grilli J, Cosentino Lagomarsino M, Bokinsky G, Tans SJ. ppGpp is a bacterial cell size regulator. Curr Biol 2021; 32:870-877.e5. [PMID: 34990598 DOI: 10.1016/j.cub.2021.12.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/27/2021] [Accepted: 12/13/2021] [Indexed: 10/19/2022]
Abstract
Growth and division are central to cell size. Bacteria achieve size homeostasis by dividing when growth has added a constant size since birth, termed the adder principle, by unknown mechanisms.1,2 Growth is well known to be regulated by guanosine tetraphosphate (ppGpp), which controls diverse processes from ribosome production to metabolic enzyme activity and replication initiation and whose absence or excess can induce stress, filamentation, and small growth-arrested cells.3-6 These observations raise unresolved questions about the relation between ppGpp and size homeostasis mechanisms during normal exponential growth. Here, to untangle effects of ppGpp and nutrients, we gained control of cellular ppGpp by inducing the synthesis and hydrolysis enzymes RelA and Mesh1. We found that ppGpp not only exerts control over the growth rate but also over cell division and thus the steady state cell size. In response to changes in ppGpp level, the added size already establishes its new constant value while the growth rate still adjusts, aided by accelerated or delayed divisions. Moreover, the magnitude of the added size and resulting steady-state birth size correlate consistently with the ppGpp level, rather than with the growth rate, which results in cells of different size that grow equally fast. Our findings suggest that ppGpp serves as a key regulator that coordinates cell size and growth control.
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Affiliation(s)
- Ferhat Büke
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands; AMOLF, Amsterdam, the Netherlands
| | - Jacopo Grilli
- The Abdus Salam International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34014 Trieste, Italy
| | - Marco Cosentino Lagomarsino
- IFOM, FIRC Institute of Molecular Oncology, Via Adamello 16, 20143, Milan, Italy; Physics Department, University of Milan, and I.N.F.N., Via Celoria 16, 20133, Milan, Italy
| | - Gregory Bokinsky
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.
| | - Sander J Tans
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands; AMOLF, Amsterdam, the Netherlands.
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8
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Zhu L, Rajendram M, Huang KC. Effects of fixation on bacterial cellular dimensions and integrity. iScience 2021; 24:102348. [PMID: 33912815 PMCID: PMC8066382 DOI: 10.1016/j.isci.2021.102348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 01/25/2021] [Accepted: 03/18/2021] [Indexed: 11/22/2022] Open
Abstract
Fixation facilitates imaging of subcellular localization and cell morphology, yet it remains unknown how fixation affects cellular dimensions and intracellular fluorescence patterns, particularly during long-term storage. Here, we characterized the effects of multiple fixatives on several bacterial species. Fixation generally reduced cell length by 5-15%; single-cell tracking in microfluidics revealed that the length decrease was an aggregate effect of many steps in the fixation protocol and that fluorescence of cytoplasmic GFP but not membrane-bound MreB-msfGFP was rapidly lost with formaldehyde-based fixatives. Cellular dimensions were preserved in formaldehyde-based fixatives for ≥4 days, but methanol caused length to decrease. Although methanol preserved cytoplasmic fluorescence better than formaldehyde-based fixatives, some Escherichia coli cells were able to grow directly after fixation. Moreover, methanol fixation caused lysis in a subpopulation of cells, with virtually all Bacillus subtilis cells lysing after one day. These findings highlight tradeoffs between maintenance of fluorescence and membrane integrity for future applications of fixation.
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Affiliation(s)
- Lillian Zhu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Manohary Rajendram
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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9
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Bhambhani A, Iadicicco I, Lee J, Ahmed S, Belfatto M, Held D, Marconi A, Parks A, Stewart CR, Margolin W, Levin PA, Haeusser DP. Bacteriophage SP01 Gene Product 56 Inhibits Bacillus subtilis Cell Division by Interacting with FtsL and Disrupting Pbp2B and FtsW Recruitment. J Bacteriol 2020; 203:e00463-20. [PMID: 33077634 PMCID: PMC7950406 DOI: 10.1128/jb.00463-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022] Open
Abstract
Previous work identified gene product 56 (gp56), encoded by the lytic bacteriophage SP01, as being responsible for inhibition of Bacillus subtilis cell division during its infection. Assembly of the essential tubulin-like protein FtsZ into a ring-shaped structure at the nascent site of cytokinesis determines the timing and position of division in most bacteria. This FtsZ ring serves as a scaffold for recruitment of other proteins into a mature division-competent structure permitting membrane constriction and septal cell wall synthesis. Here, we show that expression of the predicted 9.3-kDa gp56 of SP01 inhibits later stages of B. subtilis cell division without altering FtsZ ring assembly. Green fluorescent protein-tagged gp56 localizes to the membrane at the site of division. While its localization does not interfere with recruitment of early division proteins, gp56 interferes with the recruitment of late division proteins, including Pbp2b and FtsW. Imaging of cells with specific division components deleted or depleted and two-hybrid analyses suggest that gp56 localization and activity depend on its interaction with FtsL. Together, these data support a model in which gp56 interacts with a central part of the division machinery to disrupt late recruitment of the division proteins involved in septal cell wall synthesis.IMPORTANCE Studies over the past decades have identified bacteriophage-encoded factors that interfere with host cell shape or cytokinesis during viral infection. The phage factors causing cell filamentation that have been investigated to date all act by targeting FtsZ, the conserved prokaryotic tubulin homolog that composes the cytokinetic ring in most bacteria and some groups of archaea. However, the mechanisms of several phage factors that inhibit cytokinesis, including gp56 of bacteriophage SP01 of Bacillus subtilis, remain unexplored. Here, we show that, unlike other published examples of phage inhibition of cytokinesis, gp56 blocks B. subtilis cell division without targeting FtsZ. Rather, it utilizes the assembled FtsZ cytokinetic ring to localize to the division machinery and to block recruitment of proteins needed for septal cell wall synthesis.
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Affiliation(s)
- Amit Bhambhani
- Biology Department, Canisius College, Buffalo, New York, USA
| | | | - Jules Lee
- Biology Department, Canisius College, Buffalo, New York, USA
| | - Syed Ahmed
- Biology Department, Canisius College, Buffalo, New York, USA
| | - Max Belfatto
- Biology Department, Canisius College, Buffalo, New York, USA
| | - David Held
- Biology Department, Canisius College, Buffalo, New York, USA
| | - Alexia Marconi
- Biology Department, Canisius College, Buffalo, New York, USA
| | - Aaron Parks
- Biology Department, Canisius College, Buffalo, New York, USA
| | | | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston, Texas, USA
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
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10
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Moreno-del Álamo M, Marchisone C, Alonso JC. Antitoxin ε Reverses Toxin ζ-Facilitated Ampicillin Dormants. Toxins (Basel) 2020; 12:toxins12120801. [PMID: 33333975 PMCID: PMC7765365 DOI: 10.3390/toxins12120801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 11/16/2022] Open
Abstract
Toxin-antitoxin (TA) modules are ubiquitous in bacteria, but their biological importance in stress adaptation remains a matter of debate. The inactive ζ-ε2-ζ TA complex is composed of one labile ε2 antitoxin dimer flanked by two stable ζ toxin monomers. Free toxin ζ reduces the ATP and GTP levels, increases the (p)ppGpp and c-di-AMP pool, inactivates a fraction of uridine diphosphate-N-acetylglucosamine, and induces reversible dormancy. A small subpopulation, however, survives toxin action. Here, employing a genetic orthogonal control of ζ and ε levels, the fate of bacteriophage SPP1 infection was analyzed. Toxin ζ induces an active slow-growth state that halts SPP1 amplification, but it re-starts after antitoxin expression rather than promoting abortive infection. Toxin ζ-induced and toxin-facilitated ampicillin (Amp) dormants have been revisited. Transient toxin ζ expression causes a metabolic heterogeneity that induces toxin and Amp dormancy over a long window of time rather than cell persistence. Antitoxin ε expression, by reversing ζ activities, facilitates the exit of Amp-induced dormancy both in rec+ and recA cells. Our findings argue that an unexploited target to fight against antibiotic persistence is to disrupt toxin-antitoxin interactions.
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11
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Influence of Lactic Acid on Cell Cycle Progressions in Lactobacillus bulgaricus During Batch Culture. Appl Biochem Biotechnol 2020; 193:912-924. [PMID: 33206317 DOI: 10.1007/s12010-020-03459-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/08/2020] [Indexed: 02/02/2023]
Abstract
Lactic acid has been proved to inhibit the proliferation of lactic acid bacteria in the fermentation process. To shed light on the cell cycle alterations in acidic conditions, the cell division of Lactobacillus bulgaricus sp1.1 in batch culture was analyzed directly by implementing of the intracellular fluorescent tracking assay in different pH adjusted by lactic acid. Cell proliferation and cell division were investigated to be negatively controlled by the decrease of pH, and pH 4.1 was the critical condition of downregulating cell division but retains cell culturability. The cell area and cell length in pH 4.1 were examined by using fluorescent labeling, and they reduced to about 29.18-34.89% and 32.67-40% of cells cultured in the unacidified medium, respectively. The DNA replication initiation was undergoing prompted by the low extent of DNA condensation and higher expression of the dnaA gene in this critical pH. The results indicated that the cell cycle progressions of Lactobacillus bulgaricus sp1.1 in acidic conditions were arrested at intracellular biomass accumulation and cell division stage. These findings provide fundamental insight into cell cycle control of the acidic environment in Lactobacillus bulgaricus sp1.1.
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12
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Raghunathan S, Chimthanawala A, Krishna S, Vecchiarelli AG, Badrinarayanan A. Asymmetric chromosome segregation and cell division in DNA damage-induced bacterial filaments. Mol Biol Cell 2020; 31:2920-2931. [PMID: 33112716 PMCID: PMC7927188 DOI: 10.1091/mbc.e20-08-0547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Faithful propagation of life requires coordination of DNA replication and segregation with cell growth and division. In bacteria, this results in cell size homeostasis and periodicity in replication and division. The situation is perturbed under stress such as DNA damage, which induces filamentation as cell cycle progression is blocked to allow for repair. Mechanisms that release this morphological state for reentry into wild-type growth are unclear. Here we show that damage-induced Escherichia coli filaments divide asymmetrically, producing short daughter cells that tend to be devoid of damage and have wild-type size and growth dynamics. The Min-system primarily determines division site location in the filament, with additional regulation of division completion by chromosome segregation. Collectively, we propose that coordination between chromosome (and specifically terminus) segregation and cell division may result in asymmetric division in damage-induced filaments and facilitate recovery from a stressed state.
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Affiliation(s)
- Suchitha Raghunathan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and.,The University of Trans-Disciplinary Health Sciences and Technology (TDU), Bangalore 560064, India
| | - Afroze Chimthanawala
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and.,SASTRA University, Thanjavur, Tamil Nadu 613401, India
| | - Sandeep Krishna
- National Centre for Biological Sciences, Tata Institute of Fundamental Research and.,Simons Centre for the Study of Living Machines, Bangalore 560065, India
| | - Anthony G Vecchiarelli
- Molecular, Cellular, and Developmental Biology Department, Biological Sciences Building, University of Michigan, Ann Arbor, Michigan 48109
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13
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Atolia E, Cesar S, Arjes HA, Rajendram M, Shi H, Knapp BD, Khare S, Aranda-Díaz A, Lenski RE, Huang KC. Environmental and Physiological Factors Affecting High-Throughput Measurements of Bacterial Growth. mBio 2020; 11:e01378-20. [PMID: 33082255 PMCID: PMC7587430 DOI: 10.1128/mbio.01378-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/10/2020] [Indexed: 11/20/2022] Open
Abstract
Bacterial growth under nutrient-rich and starvation conditions is intrinsically tied to the environmental history and physiological state of the population. While high-throughput technologies have enabled rapid analyses of mutant libraries, technical and biological challenges complicate data collection and interpretation. Here, we present a framework for the execution and analysis of growth measurements with improved accuracy over that of standard approaches. Using this framework, we demonstrate key biological insights that emerge from consideration of culturing conditions and history. We determined that quantification of the background absorbance in each well of a multiwell plate is critical for accurate measurements of maximal growth rate. Using mathematical modeling, we demonstrated that maximal growth rate is dependent on initial cell density, which distorts comparisons across strains with variable lag properties. We established a multiple-passage protocol that alleviates the substantial effects of glycerol on growth in carbon-poor media, and we tracked growth rate-mediated fitness increases observed during a long-term evolution of Escherichia coli in low glucose concentrations. Finally, we showed that growth of Bacillus subtilis in the presence of glycerol induces a long lag in the next passage due to inhibition of a large fraction of the population. Transposon mutagenesis linked this phenotype to the incorporation of glycerol into lipoteichoic acids, revealing a new role for these envelope components in resuming growth after starvation. Together, our investigations underscore the complex physiology of bacteria during bulk passaging and the importance of robust strategies to understand and quantify growth.IMPORTANCE How starved bacteria adapt and multiply under replete nutrient conditions is intimately linked to their history of previous growth, their physiological state, and the surrounding environment. While automated equipment has enabled high-throughput growth measurements, data interpretation and knowledge gaps regarding the determinants of growth kinetics complicate comparisons between strains. Here, we present a framework for growth measurements that improves accuracy and attenuates the effects of growth history. We determined that background absorbance quantification and multiple passaging cycles allow for accurate growth rate measurements even in carbon-poor media, which we used to reveal growth-rate increases during long-term laboratory evolution of Escherichia coli Using mathematical modeling, we showed that maximum growth rate depends on initial cell density. Finally, we demonstrated that growth of Bacillus subtilis with glycerol inhibits the future growth of most of the population, due to lipoteichoic acid synthesis. These studies highlight the challenges of accurate quantification of bacterial growth behaviors.
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Affiliation(s)
- Esha Atolia
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Spencer Cesar
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Heidi A Arjes
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Manohary Rajendram
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Handuo Shi
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Benjamin D Knapp
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA
| | - Somya Khare
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Andrés Aranda-Díaz
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Kerwyn Casey Huang
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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14
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Bandekar AC, Subedi S, Ioerger TR, Sassetti CM. Cell-Cycle-Associated Expression Patterns Predict Gene Function in Mycobacteria. Curr Biol 2020; 30:3961-3971.e6. [PMID: 32916109 PMCID: PMC7578119 DOI: 10.1016/j.cub.2020.07.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/26/2020] [Accepted: 07/22/2020] [Indexed: 12/20/2022]
Abstract
Although the major events in prokaryotic cell cycle progression are likely to be coordinated with transcriptional and metabolic changes, these processes remain poorly characterized. Unlike many rapidly growing bacteria, DNA replication and cell division are temporally resolved in mycobacteria, making these slow-growing organisms a potentially useful system to investigate the prokaryotic cell cycle. To determine whether cell-cycle-dependent gene regulation occurs in mycobacteria, we characterized the temporal changes in the transcriptome of synchronously replicating populations of Mycobacterium tuberculosis (Mtb). By enriching for genes that display a sinusoidal expression pattern, we discover 485 genes that oscillate with a period consistent with the cell cycle. During cytokinesis, the timing of gene induction could be used to predict the timing of gene function, as mRNA abundance was found to correlate with the order in which proteins were recruited to the developing septum. Similarly, the expression pattern of primary metabolic genes could be used to predict the relative importance of these pathways for different cell cycle processes. Pyrimidine synthetic genes peaked during DNA replication, and their depletion caused a filamentation phenotype that phenocopied defects in this process. In contrast, the inosine monophasphate dehydrogenase dedicated to guanosine synthesis, GuaB2, displayed the opposite expression pattern and its depletion perturbed septation. Together, these data imply obligate coordination between primary metabolism and cell division and identify periodically regulated genes that can be related to specific cell biological functions.
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Affiliation(s)
- Aditya C Bandekar
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Sishir Subedi
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Thomas R Ioerger
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX 77843, USA.
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
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15
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Pomposello MM, Nemes K, Mosovsky K. Dietary antioxidant seleno-L-methionine protects macrophages infected with Burkholderia thailandensis. PLoS One 2020; 15:e0238174. [PMID: 32881891 PMCID: PMC7470333 DOI: 10.1371/journal.pone.0238174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/11/2020] [Indexed: 12/29/2022] Open
Abstract
Burkholderia pseudomallei is a facultative intracellular pathogen and the causative agent of melioidosis, a potentially life-threatening disease endemic in Southeast Asia and Northern Australia. Treatment of melioidosis is a long and costly process and the pathogen is inherently resistant to several classes of antibiotics, therefore there is a need for new treatments that can help combat the pathogen. Previous work has shown that the combination of interferon-gamma, an immune system activator, and the antibiotic ceftazidime synergistically reduced the bacterial burden of RAW 264.7 macrophages that had been infected with either B. pseudomallei or Burkholderia thailandensis. The mechanism of the interaction was found to be partially dependent on interferon-gamma-induced production of reactive oxygen species inside the macrophages. To further confirm the role of reactive oxygen species in the effectiveness of the combination treatment, we investigated the impact of the antioxidant and reactive oxygen species scavenger, seleno-L-methionine, on intracellular and extracellular bacterial burden of the infected macrophages. In a dose-dependent manner, high concentrations of seleno-L-methionine (1000 μM) were protective towards infected macrophages, resulting in a reduction of bacteria, on its own, that exceeded the reduction caused by the antibiotic alone and rivaled the effect of ceftazidime and interferon-gamma combined. Seleno-L-methionine treatment also resulted in improved viability of infected macrophages compared to untreated controls. We show that the protective effect of seleno-L-methionine was partly due to its inhibition of bacterial growth. In summary, our study shows a role for high dose seleno-L-methionine to protect and treat macrophages infected with B. thailandensis.
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Affiliation(s)
- Michelle M. Pomposello
- Department of Biological Sciences, Moravian College, Bethlehem, Pennsylvania, United States of America
| | - Kaitlyn Nemes
- Department of Biological Sciences, Moravian College, Bethlehem, Pennsylvania, United States of America
| | - Kara Mosovsky
- Department of Biological Sciences, Moravian College, Bethlehem, Pennsylvania, United States of America
- * E-mail:
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16
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Khare S, Hsin J, Sorto NA, Nepomuceno GM, Shaw JT, Shi H, Huang KC. FtsZ-Independent Mechanism of Division Inhibition by the Small Molecule PC190723 in Escherichia coli. ACTA ACUST UNITED AC 2020; 3:e1900021. [PMID: 32648693 DOI: 10.1002/adbi.201900021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/07/2019] [Indexed: 11/12/2022]
Abstract
While cell division is a critical process in cellular proliferation, very few antibiotics have been identified that target the bacterial cell-division machinery. Recent studies have shown that the small molecule PC190723 inhibits cell division in several Gram-positive bacteria, with a hypothesized mechanism of action involving direct targeting of the tubulin homolog FtsZ, which is essential for division in virtually all bacterial species. Here, it is shown that PC190723 also inhibits cell division in the Gram-negative bacterium Escherichia coli if the outer membrane permeability barrier is compromised genetically or chemically. The results show that the equivalent FtsZ mutations conferring PC190723 resistance in Staphylococcus aureus do not protect E. coli against PC190723, and that suppressors of PC190723 sensitivity in E. coli, which do not generically decrease outer membrane permeability, do not map to FtsZ or other division proteins. These suppressors display a wide range of morphological and growth phenotypes, and one exhibits a death phenotype in the stationary phase similar to that of a mutant with disrupted lipid homeostasis. Finally, a complementing FtsZ-msfGFP fusion is used to show that PC190723 does not affect the Z-ring structure. Taken together, the findings suggest that PC190723 inhibits growth and division in E. coli without targeting FtsZ. This study highlights the importance of utilizing a combination of genetic, chemical, and single-cell approaches to dissect the mechanisms of action of new antibiotics, which are not necessarily conserved across bacterial species.
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Affiliation(s)
- Somya Khare
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Jen Hsin
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Nohemy A Sorto
- Department of Chemistry, University of California at Davis, Davis, CA, 95616, USA
| | | | - Jared T Shaw
- Department of Chemistry, University of California at Davis, Davis, CA, 95616, USA
| | - Handuo Shi
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.,Department of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA.,Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA
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17
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Arjes HA, Vo L, Dunn CM, Willis L, DeRosa CA, Fraser CL, Kearns DB, Huang KC. Biosurfactant-Mediated Membrane Depolarization Maintains Viability during Oxygen Depletion in Bacillus subtilis. Curr Biol 2020; 30:1011-1022.e6. [PMID: 32059765 PMCID: PMC7153240 DOI: 10.1016/j.cub.2020.01.073] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/09/2019] [Accepted: 01/23/2020] [Indexed: 12/26/2022]
Abstract
The presence or absence of oxygen in the environment is a strong effector of cellular metabolism and physiology. Like many eukaryotes and some bacteria, Bacillus subtilis primarily utilizes oxygen during respiration to generate ATP. Despite the importance of oxygen for B. subtilis survival, we know little about how populations adapt to shifts in oxygen availability. Here, we find that when oxygen was depleted from stationary phase B. subtilis cultures, ∼90% of cells died while the remaining cells maintained colony-forming ability. We discover that production of the antimicrobial surfactin confers two oxygen-related fitness benefits: it increases aerobic growth yield by increasing oxygen diffusion, and it maintains viability during oxygen depletion by depolarizing the membrane. Strains unable to produce surfactin exhibited an ∼50-fold reduction in viability after oxygen depletion. Surfactin treatment of these cells led to membrane depolarization and reduced ATP production. Chemical and genetic perturbations that alter oxygen consumption or redox state support a model in which surfactin-mediated membrane depolarization maintains viability through slower oxygen consumption and/or a shift to a more reduced metabolic profile. These findings highlight the importance of membrane potential in regulating cell physiology and growth, and demonstrate that antimicrobials that depolarize cell membranes can benefit cells when the terminal electron acceptor in respiration is limiting. This foundational knowledge has deep implications for environmental microbiology, clinical anti-bacterial therapy, and industrial biotechnology.
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Affiliation(s)
- Heidi A Arjes
- Department of Bioengineering, Stanford University School of Medicine, 443 via Ortega, Stanford, CA 94305, USA
| | - Lam Vo
- Department of Bioengineering, Stanford University School of Medicine, 443 via Ortega, Stanford, CA 94305, USA
| | - Caroline M Dunn
- Department of Biology, 1001 E 3rd Street, Indiana University, Bloomington, IN 47405, USA
| | - Lisa Willis
- Department of Bioengineering, Stanford University School of Medicine, 443 via Ortega, Stanford, CA 94305, USA
| | - Christopher A DeRosa
- Department of Chemistry, McCormick Road, University of Virginia, Charlottesville, VA 22904, USA
| | - Cassandra L Fraser
- Department of Chemistry, McCormick Road, University of Virginia, Charlottesville, VA 22904, USA
| | - Daniel B Kearns
- Department of Biology, 1001 E 3rd Street, Indiana University, Bloomington, IN 47405, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University School of Medicine, 443 via Ortega, Stanford, CA 94305, USA; Department of Microbiology & Immunology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, 499 Illinois Street, San Francisco, CA 94158, USA.
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18
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Mayer C, Sass P, Brötz-Oesterhelt H. Consequences of dosing and timing on the antibacterial effects of ADEP antibiotics. Int J Med Microbiol 2019; 309:151329. [PMID: 31331697 DOI: 10.1016/j.ijmm.2019.151329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 07/02/2019] [Accepted: 07/09/2019] [Indexed: 10/26/2022] Open
Abstract
Antibiotic acyldepsipeptides (ADEPs) exert potent antibacterial activity in rodent models of bacterial infection and exceptional efficacy against persister cells of methicillin-resistant Staphylococcus aureus (MRSA). The mechanism of ADEP action is unusual in that the antibiotic releases the destructive capacity of over-activated ClpP, the proteolytic core of the bacterial Clp protease. The essential bacterial cell division protein FtsZ had emerged in a previous study as a preferred protein substrate of ADEP-activated ClpP but it is definitely not the only cellular substrate. In the current study, we set out to follow the morphological changes that lead to ADEP-mediated bacterial death in S. aureus and Bacillus subtilis, differentiating between antibacterial effects at low and high ADEP concentrations. Here, fluorescence and time-lapse microscopy data show that cells adopt a characteristic phenotype of cell division inhibition at ADEP levels close to the MIC, but retain the capacity to form viable daughter cells for a substantial period of time when transferred to ADEP-free growth medium. After extended exposure to low ADEP concentrations, nucleoids of B. subtilis started to disorganize and upon compound removal many cells failed to re-organize nucleoids, re-initiate cytokinesis and consequently died. Survival versus cell death of filamentous cells attempting recovery depended on the timing of completion of new septa in relation to the loss of cell envelope integrity. We show that the potential to recover after ADEP removal depends on the antibiotic concentration as well as the treatment duration. When exposed to ADEP at concentrations well above the MIC, biomass production ceased rapidly as did the potential to recover. In time-kill studies both long-time exposure to low ADEP levels as well as short-time exposure to high concentrations proved highly effective, while intermittent concentrations and time frames were not. We here provide new insights into the antimicrobial activity of ADEP antibiotics and the consequences of dosing and timing for bacterial physiology which should be considered in view of a potential therapeutic application of ADEPs.
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Affiliation(s)
- Christian Mayer
- Interfaculty Institute for Microbiology and Infection Medicine, Department for Microbial Bioactive Compounds, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Peter Sass
- Interfaculty Institute for Microbiology and Infection Medicine, Department for Microbial Bioactive Compounds, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.
| | - Heike Brötz-Oesterhelt
- Interfaculty Institute for Microbiology and Infection Medicine, Department for Microbial Bioactive Compounds, University of Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.
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19
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Levin PA, Taheri-Araghi S. One is Nothing without the Other: Theoretical and Empirical Analysis of Cell Growth and Cell Cycle Progression. J Mol Biol 2019; 431:2061-2067. [PMID: 31026450 DOI: 10.1016/j.jmb.2019.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/25/2019] [Accepted: 04/02/2019] [Indexed: 11/19/2022]
Abstract
Small, fast-growing bacteria make ideal subjects for genetic and quantitative analysis alike. Long the darling of theoreticians, efforts to understand the relationship between cell growth and cell cycle progression in bacterial systems have been propelled by modelers and empiricist in equal measure. Taking a historical approach, here we break down early work in this area, the impact it had on how the bacterial cell cycle is understood and interrogated, and changes brought by the advent of high-throughput techniques for the analysis of individual bacterial cells in culture.
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Affiliation(s)
- Petra Anne Levin
- Department of Biology, Washington University in St. Louis, MO 63130, United States.
| | - Sattar Taheri-Araghi
- Department of Physics and Astronomy, California State University, Northridge, CA 91311, United States.
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20
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Araújo‐Bazán L, Huecas S, Valle J, Andreu D, Andreu JM. Synthetic developmental regulator MciZ targets FtsZ across
Bacillus
species and inhibits bacterial division. Mol Microbiol 2019; 111:965-980. [DOI: 10.1111/mmi.14198] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2019] [Indexed: 01/20/2023]
Affiliation(s)
| | - Sonia Huecas
- Centro de Investigaciones Biológicas CSIC Madrid Spain
| | - Javier Valle
- Department of Experimental and Health Sciences Universitat Pompeu Fabra Barcelona Spain
| | - David Andreu
- Department of Experimental and Health Sciences Universitat Pompeu Fabra Barcelona Spain
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21
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Dewachter L, Verstraeten N, Fauvart M, Michiels J. An integrative view of cell cycle control in Escherichia coli. FEMS Microbiol Rev 2018; 42:116-136. [PMID: 29365084 DOI: 10.1093/femsre/fuy005] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/19/2018] [Indexed: 11/14/2022] Open
Abstract
Bacterial proliferation depends on the cells' capability to proceed through consecutive rounds of the cell cycle. The cell cycle consists of a series of events during which cells grow, copy their genome, partition the duplicated DNA into different cell halves and, ultimately, divide to produce two newly formed daughter cells. Cell cycle control is of the utmost importance to maintain the correct order of events and safeguard the integrity of the cell and its genomic information. This review covers insights into the regulation of individual key cell cycle events in Escherichia coli. The control of initiation of DNA replication, chromosome segregation and cell division is discussed. Furthermore, we highlight connections between these processes. Although detailed mechanistic insight into these connections is largely still emerging, it is clear that the different processes of the bacterial cell cycle are coordinated to one another. This careful coordination of events ensures that every daughter cell ends up with one complete and intact copy of the genome, which is vital for bacterial survival.
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Affiliation(s)
- Liselot Dewachter
- Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, B-3001 Leuven, Belgium.,VIB Center for Microbiology, B-3001 Leuven, Belgium
| | - Natalie Verstraeten
- Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, B-3001 Leuven, Belgium.,VIB Center for Microbiology, B-3001 Leuven, Belgium
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, B-3001 Leuven, Belgium.,VIB Center for Microbiology, B-3001 Leuven, Belgium.,Department of Life Sciences and Imaging, Smart Electronics Unit, imec, B-3001 Leuven, Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven-University of Leuven, B-3001 Leuven, Belgium.,VIB Center for Microbiology, B-3001 Leuven, Belgium
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22
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Kleckner NE, Chatzi K, White MA, Fisher JK, Stouf M. Coordination of Growth, Chromosome Replication/Segregation, and Cell Division in E. coli. Front Microbiol 2018; 9:1469. [PMID: 30038602 PMCID: PMC6046412 DOI: 10.3389/fmicb.2018.01469] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/12/2018] [Indexed: 11/13/2022] Open
Abstract
Bacterial cells growing in steady state maintain a 1:1:1 relationship between an appropriate mass increase, a round of DNA replication plus sister chromosome segregation, and cell division. This is accomplished without the cell cycle engine found in eukaryotic cells. We propose here a formal logic, and an accompanying mechanism, for how such coordination could be provided in E. coli. Completion of chromosomal and divisome-related events would lead, interactively, to a “progression control complex” (PCC) which provides integrated physical coupling between sister terminus regions and the nascent septum. When a cell has both (i) achieved a sufficient mass increase, and (ii) the PCC has developed, a conformational change in the PCC occurs. This change results in “progression permission,” which triggers both onset of cell division and release of terminus regions. Release of the terminus region, in turn, directly enables a next round of replication initiation via physical changes transmitted through the nucleoid. Division and initiation are then implemented, each at its own rate and timing, according to conditions present. Importantly: (i) the limiting step for progression permission may be either completion of the growth requirement or the chromosome/divisome processes required for assembly of the PCC; and, (ii) the outcome of the proposed process is granting of permission to progress, not determination of the absolute or relative timings of downstream events. This basic logic, and the accompanying mechanism, can explain coordination of events in both slow and fast growth conditions; can accommodate diverse variations and perturbations of cellular events; and is compatible with existing mathematical descriptions of the E. coli cell cycle. Also, while our proposition is specifically designed to provide 1:1:1 coordination among basic events on a “per-cell cycle” basis, it is a small step to further envision permission progression is also the target of basic growth rate control. In such a case, the rate of mass accumulation (or its equivalent) would determine the length of the interval between successive permission events and, thus, successive cell divisions and successive replication initiations.
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Affiliation(s)
- Nancy E Kleckner
- Department of Molecular and Cellular Biology Harvard University, Cambridge, MA, United States
| | - Katerina Chatzi
- Department of Molecular and Cellular Biology Harvard University, Cambridge, MA, United States
| | - Martin A White
- Department of Molecular and Cellular Biology Harvard University, Cambridge, MA, United States
| | | | - Mathieu Stouf
- Department of Molecular and Cellular Biology Harvard University, Cambridge, MA, United States
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23
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Wehrens M, Ershov D, Rozendaal R, Walker N, Schultz D, Kishony R, Levin PA, Tans SJ. Size Laws and Division Ring Dynamics in Filamentous Escherichia coli cells. Curr Biol 2018; 28:972-979.e5. [PMID: 29502951 DOI: 10.1016/j.cub.2018.02.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 12/07/2017] [Accepted: 02/05/2018] [Indexed: 10/17/2022]
Abstract
Our understanding of bacterial cell size control is based mainly on stress-free growth conditions in the laboratory [1-10]. In the real world, however, bacteria are routinely faced with stresses that produce long filamentous cell morphologies [11-28]. Escherichia coli is observed to filament in response to DNA damage [22-25], antibiotic treatment [11-14, 28], host immune systems [15, 16], temperature [17], starvation [20], and more [18, 19, 21], conditions which are relevant to clinical settings and food preservation [26]. This shape plasticity is considered a survival strategy [27]. Size control in this regime remains largely unexplored. Here we report that E. coli cells use a dynamic size ruler to determine division locations combined with an adder-like mechanism to trigger divisions. As filamentous cells increase in size due to growth, or decrease in size due to divisions, its multiple Fts division rings abruptly reorganize to remain one characteristic cell length away from the cell pole and two such length units away from each other. These rules can be explained by spatiotemporal oscillations of Min proteins. Upon removal of filamentation stress, the cells undergo a sequence of division events, randomly at one of the possible division sites, on average after the time required to grow one characteristic cell size. These results indicate that E. coli cells continuously keep track of absolute length to control size, suggest a wider relevance for the adder principle beyond the control of normally sized cells, and provide a new perspective on the function of the Fts and Min systems.
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Affiliation(s)
| | - Dmitry Ershov
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands
| | | | - Noreen Walker
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands
| | - Daniel Schultz
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel; Department of Systems Biology, Harvard Medical School, Boston MA 02138, USA
| | - Roy Kishony
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel; Department of Systems Biology, Harvard Medical School, Boston MA 02138, USA
| | - Petra Anne Levin
- Department of Biology, Washington University, One Brookings Drive, St. Louis, MO, USA
| | - Sander J Tans
- AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands; Bionanoscience Department, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands.
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24
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Abstract
When deprived of FtsZ, Escherichia coli cells (VIP205) grown in liquid form long nonseptated filaments due to their inability to assemble an FtsZ ring and their failure to recruit subsequent divisome components. These filaments fail to produce colonies on solid medium, in which synthesis of FtsZ is induced, upon being diluted by a factor greater than 4. However, once the initial FtsZ levels are recovered in liquid culture, they resume division, and their plating efficiency returns to normal. The potential septation sites generated in the FtsZ-deprived filaments are not annihilated, and once sufficient FtsZ is accumulated, they all become active and divide to produce cells of normal length. FtsZ-deprived cells accumulate defects in their physiology, including an abnormally high number of unsegregated nucleoids that may result from the misplacement of FtsK. Their membrane integrity becomes compromised and the amount of membrane proteins, such as FtsK and ZipA, increases. FtsZ-deprived cells also show an altered expression pattern, namely, transcription of several genes responding to DNA damage increases, whereas transcription of some ribosomal or global transcriptional regulators decreases. We propose that the changes caused by the depletion of FtsZ, besides stopping division, weaken the cell, diminishing its resiliency to minor challenges, such as dilution stress. Our results suggest a role for FtsZ, in addition to its already known effect in the constriction of E. coli, in protecting the nondividing cells against minor stress. This protection can even be exerted when an inactive FtsZ is produced, but it is lost when the protein is altogether absent. These results have implications in fields like synthetic biology or antimicrobial discovery. The construction of synthetic divisomes in the test tube may need to preserve unsuspected roles, such as this newly found FtsZ property, to guarantee the stability of artificial containers. Whereas the effects on viability caused by inhibiting the activity of FtsZ may be partly overcome by filamentation, the absence of FtsZ is not tolerated by E. coli, an observation that may help in the design of effective antimicrobial compounds.
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25
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Araújo-Bazán L, Ruiz-Avila LB, Andreu D, Huecas S, Andreu JM. Cytological Profile of Antibacterial FtsZ Inhibitors and Synthetic Peptide MciZ. Front Microbiol 2016; 7:1558. [PMID: 27752253 PMCID: PMC5045927 DOI: 10.3389/fmicb.2016.01558] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/16/2016] [Indexed: 11/26/2022] Open
Abstract
Cell division protein FtsZ is the organizer of the cytokinetic ring in almost all bacteria and a target for the discovery of new antibacterial agents that are needed to counter widespread antibiotic resistance. Bacterial cytological profiling, using quantitative microscopy, is a powerful approach for identifying the mechanism of action of antibacterial molecules affecting different cellular pathways. We have determined the cytological profile on Bacillus subtilis cells of a selection of small molecule inhibitors targeting FtsZ on different binding sites. FtsZ inhibitors lead to long undivided cells, impair the normal assembly of FtsZ into the midcell Z-rings, induce aberrant ring distributions, punctate FtsZ foci, membrane spots and also modify nucleoid length. Quantitative analysis of cell and nucleoid length combined, or the Z-ring distribution, allows categorizing FtsZ inhibitors and to distinguish them from antibiotics with other mechanisms of action, which should be useful for identifying new antibacterial FtsZ inhibitors. Biochemical assays of FtsZ polymerization and GTPase activity combined explain the cellular effects of the FtsZ polymer stabilizing agent PC190723 and its fragments. MciZ is a 40-aminoacid endogenous inhibitor of cell division normally expressed during sporulation in B. subtilis. Using FtsZ cytological profiling we have determined that exogenous synthetic MciZ is an effective inhibitor of B. subtilis cell division, Z-ring formation and localization. This finding supports our cell-based approach to screen for FtsZ inhibitors and opens new possibilities for peptide inhibitors of bacterial cell division.
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Affiliation(s)
- Lidia Araújo-Bazán
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Laura B Ruiz-Avila
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - David Andreu
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra Barcelona, Spain
| | - Sonia Huecas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - José M Andreu
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
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26
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Peters JM, Colavin A, Shi H, Czarny TL, Larson MH, Wong S, Hawkins JS, Lu CHS, Koo BM, Marta E, Shiver AL, Whitehead EH, Weissman JS, Brown ED, Qi LS, Huang KC, Gross CA. A Comprehensive, CRISPR-based Functional Analysis of Essential Genes in Bacteria. Cell 2016; 165:1493-1506. [PMID: 27238023 PMCID: PMC4894308 DOI: 10.1016/j.cell.2016.05.003] [Citation(s) in RCA: 446] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/28/2016] [Accepted: 04/20/2016] [Indexed: 12/28/2022]
Abstract
Essential gene functions underpin the core reactions required for cell viability, but their contributions and relationships are poorly studied in vivo. Using CRISPR interference, we created knockdowns of every essential gene in Bacillus subtilis and probed their phenotypes. Our high-confidence essential gene network, established using chemical genomics, showed extensive interconnections among distantly related processes and identified modes of action for uncharacterized antibiotics. Importantly, mild knockdown of essential gene functions significantly reduced stationary-phase survival without affecting maximal growth rate, suggesting that essential protein levels are set to maximize outgrowth from stationary phase. Finally, high-throughput microscopy indicated that cell morphology is relatively insensitive to mild knockdown but profoundly affected by depletion of gene function, revealing intimate connections between cell growth and shape. Our results provide a framework for systematic investigation of essential gene functions in vivo broadly applicable to diverse microorganisms and amenable to comparative analysis.
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Affiliation(s)
- Jason M Peters
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Handuo Shi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Tomasz L Czarny
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 3Z5, Canada; Michael G. DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Matthew H Larson
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Spencer Wong
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - John S Hawkins
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Biophysics Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Candy H S Lu
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Byoung-Mo Koo
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Elizabeth Marta
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Anthony L Shiver
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA; Biophysics Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Evan H Whitehead
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; UCSF Center for Systems and Synthetic Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA; Center for RNA Systems Biology, University of California, Berkeley, Berkeley, CA 94720, USA; UCSF Center for Systems and Synthetic Biology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 3Z5, Canada; Michael G. DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; ChEM-H, Stanford University, Stanford, CA 94305, USA.
| | - Kerwyn Casey Huang
- Biophysics Program, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; School of Medicine, Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA.
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27
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Connecting the dots of the bacterial cell cycle: Coordinating chromosome replication and segregation with cell division. Semin Cell Dev Biol 2016; 53:2-9. [DOI: 10.1016/j.semcdb.2015.11.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/26/2015] [Indexed: 12/20/2022]
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28
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Busiek KK, Margolin W. Bacterial actin and tubulin homologs in cell growth and division. Curr Biol 2016; 25:R243-R254. [PMID: 25784047 DOI: 10.1016/j.cub.2015.01.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In contrast to the elaborate cytoskeletal machines harbored by eukaryotic cells, such as mitotic spindles, cytoskeletal structures detectable by typical negative stain electron microscopy are generally absent from bacterial cells. As a result, for decades it was thought that bacteria lacked cytoskeletal machines. Revolutions in genomics and fluorescence microscopy have confirmed the existence not only of smaller-scale cytoskeletal structures in bacteria, but also of widespread functional homologs of eukaryotic cytoskeletal proteins. The presence of actin, tubulin, and intermediate filament homologs in these relatively simple cells suggests that primitive cytoskeletons first arose in bacteria. In bacteria such as Escherichia coli, homologs of tubulin and actin directly interact with each other and are crucial for coordinating cell growth and division. The function and direct interactions between these proteins will be the focus of this review.
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Affiliation(s)
- Kimberly K Busiek
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, University of Texas Medical School at Houston, 6431 Fannin St., Houston, TX 77030, USA.
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29
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Liu Y, Frirdich E, Taylor JA, Chan ACK, Blair KM, Vermeulen J, Ha R, Murphy MEP, Salama NR, Gaynor EC, Tanner ME. A Bacterial Cell Shape-Determining Inhibitor. ACS Chem Biol 2016; 11:981-91. [PMID: 26735022 DOI: 10.1021/acschembio.5b01039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Helicobacter pylori and Campylobacter jejuni are human pathogens and causative agents of gastric ulcers/cancer and gastroenteritis, respectively. Recent studies have uncovered a series of proteases that are responsible for maintaining the helical shape of these organisms. The H. pylori metalloprotease Csd4 and its C. jejuni homologue Pgp1 cleave the amide bond between meso-diaminopimelate and iso-d-glutamic acid in truncated peptidoglycan side chains. Deletion of either csd4 or pgp1 results in bacteria with a straight rod phenotype, a reduced ability to move in viscous media, and reduced pathogenicity. In this work, a phosphinic acid-based pseudodipeptide inhibitor was designed to act as a tetrahedral intermediate analog against the Csd4 enzyme. The phosphinic acid was shown to inhibit the cleavage of the alternate substrate, Ac-l-Ala-iso-d-Glu-meso-Dap, with a Ki value of 1.5 μM. Structural analysis of the Csd4-inhibitor complex shows that the phosphinic acid displaces the zinc-bound water and chelates the metal in a bidentate fashion. The phosphinate oxygens also interact with the key acid/base residue, Glu222, and the oxyanion-stabilizing residue, Arg86. The results are consistent with the "promoted-water pathway" mechanism for carboxypeptidase A catalysis. Studies on cultured bacteria showed that the inhibitor causes significant cell straightening when incubated with H. pylori at millimolar concentrations. A diminished, yet observable, effect on the morphology of C. jejuni was also apparent. Cell straightening was more pronounced with an acapsular C. jejuni mutant strain compared to the wild type, suggesting that the capsule impaired inhibitor accessibility. These studies demonstrate that a highly polar compound is capable of crossing the outer membrane and altering cell shape, presumably by inhibiting cell shape determinant proteases. Peptidoglycan proteases acting as cell shape determinants represent novel targets for the development of antimicrobials against these human pathogens.
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Affiliation(s)
- Yanjie Liu
- Contribution
from the Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Emilisa Frirdich
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jennifer A. Taylor
- Division
of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, United States
- Department
of Microbiology, University of Washington School of Medicine, Seattle, Washington 98195, United States
| | - Anson C. K. Chan
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Kris M. Blair
- Division
of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, United States
- Program
in Molecular and Cellular Biology, University of Washington, Seattle, Washington 98195, United States
| | - Jenny Vermeulen
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Reuben Ha
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael E. P. Murphy
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Nina R. Salama
- Division
of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, United States
- Department
of Microbiology, University of Washington School of Medicine, Seattle, Washington 98195, United States
- Program
in Molecular and Cellular Biology, University of Washington, Seattle, Washington 98195, United States
| | - Erin C. Gaynor
- Department
of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Martin E. Tanner
- Contribution
from the Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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30
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You Are What You Eat: Metabolic Control of Bacterial Division. Trends Microbiol 2016; 24:181-189. [DOI: 10.1016/j.tim.2015.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/22/2015] [Accepted: 11/24/2015] [Indexed: 12/16/2022]
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31
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Arjes HA, Lai B, Emelue E, Steinbach A, Levin PA. Mutations in the bacterial cell division protein FtsZ highlight the role of GTP binding and longitudinal subunit interactions in assembly and function. BMC Microbiol 2015; 15:209. [PMID: 26463348 PMCID: PMC4603965 DOI: 10.1186/s12866-015-0544-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/02/2015] [Indexed: 11/28/2022] Open
Abstract
Background Assembly of the tubulin-like GTPase, FtsZ, at the future division site initiates the process of bacterial cytokinesis. The FtsZ ring serves as a platform for assembly of the division machinery and constricts at the leading edge of the invaginating septum during cytokinesis. In vitro, FtsZ assembles in a GTP-dependent manner, forming straight filaments that curve upon GTP hydrolysis. FtsZ binds but cannot hydrolyze GTP as a monomer. Instead, the active site for GTP hydrolysis is formed at the monomer-monomer interface upon dimerization. While the dynamics of GTP hydrolysis and assembly have been extensively studied in vitro, significantly less is known about the role of GTP binding and hydrolysis in vivo. ftsZ84, a GTPase defective allele of Escherichia coli ftsZ, provides a striking example of the disconnect between in vivo and in vitro FtsZ assembly. Results Although ftsZ84 mutants are defective for FtsZ ring formation and division under nonpermissive conditions, they are near wild type for ring formation and division under permissive conditions. In vitro, however, purified FtsZ84 is defective in GTP binding, hydrolysis and assembly under standard reaction conditions. To clarify the nature of the FtsZ84 assembly defect, we isolated and characterized three intragenic suppressors of ftsZ84. All three suppressor mutations increased the apparent affinity of FtsZ84 for GTP, consistent with improved subunit-subunit interactions along the longitudinal interface. Although kinetic analysis indicates that the suppressor mutations increase the affinity of FtsZ84 for GTP, all three exhibit reduced rates of GTP hydrolysis and fail to support assembly in vitro. Conclusion Together, our data suggest that FtsZ, and potentially other enzymes whose assembly is similarly regulated, can compensate for defects in catalysis through increases in substrate binding and subunit-subunit interactions. In addition, these results highlight the dichotomy between commonly used in vitro assembly conditions and FtsZ ring formation in the complex intracellular milieu. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0544-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Heidi A Arjes
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA. .,Present address: Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.
| | - Bradley Lai
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Ezinwanne Emelue
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Adriana Steinbach
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
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32
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Lies M, Visser BJ, Joshi MC, Magnan D, Bates D. MioC and GidA proteins promote cell division in E. coli. Front Microbiol 2015; 6:516. [PMID: 26074904 PMCID: PMC4446571 DOI: 10.3389/fmicb.2015.00516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/09/2015] [Indexed: 11/24/2022] Open
Abstract
The well-conserved genes surrounding the E. coli replication origin, mioC and gidA, do not normally affect chromosome replication and have little known function. We report that mioC and gidA mutants exhibit a moderate cell division inhibition phenotype. Cell elongation is exacerbated by a fis deletion, likely owing to delayed replication and subsequent cell cycle stress. Measurements of replication initiation frequency and origin segregation indicate that mioC and gidA do not inhibit cell division through any effect on oriC function. Division inhibition is also independent of the two known replication/cell division checkpoints, SOS and nucleoid occlusion. Complementation analysis indicates that mioC and gidA affect cell division in trans, indicating their effect is at the protein level. Transcriptome analysis by RNA sequencing showed that expression of a cell division septum component, YmgF, is significantly altered in mioC and gidA mutants. Our data reveal new roles for the gene products of gidA and mioC in the division apparatus, and we propose that their expression, cyclically regulated by chromatin remodeling at oriC, is part of a cell cycle regulatory program coordinating replication initiation and cell division.
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Affiliation(s)
- Mark Lies
- Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA
| | - Bryan J Visser
- Integrative Molecular and Biomedical Sciences, Baylor College of Medicine Houston, TX, USA
| | - Mohan C Joshi
- Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA
| | - David Magnan
- Integrative Molecular and Biomedical Sciences, Baylor College of Medicine Houston, TX, USA
| | - David Bates
- Molecular and Human Genetics, Baylor College of Medicine Houston, TX, USA ; Integrative Molecular and Biomedical Sciences, Baylor College of Medicine Houston, TX, USA
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33
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Tsang MJ, Bernhardt TG. Guiding divisome assembly and controlling its activity. Curr Opin Microbiol 2015; 24:60-5. [PMID: 25636132 DOI: 10.1016/j.mib.2015.01.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/01/2015] [Accepted: 01/08/2015] [Indexed: 01/11/2023]
Abstract
Cell division in bacteria requires the construction of two new polar caps for the daughter cells. To constrict the cell membrane and build these new surface layers, bacteria employ a multiprotein machine called the divisome. Over the years, most of the essential division proteins have been identified and localized to the ring-like divisome apparatus. The challenge now is to determine the molecular function of these factors, how they cooperate to bring about the dramatic transformation of the mother cell envelope, and what coordinates their activity with other major cell cycle events. In this review, we discuss recent progress in these areas with an emphasis on results from the model organisms Escherichia coli and Bacillus subtilis.
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Affiliation(s)
- Mary-Jane Tsang
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, United States
| | - Thomas G Bernhardt
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, United States.
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34
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Abstract
A recent study shows that prolonged inhibition of bacterial cell division causes a block of DNA replication, which is followed by an irreversible cell cycle arrest. The finding indicates a tight coupling between cell division and DNA replication in bacteria.
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Affiliation(s)
- Kristina Jonas
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps University Marburg, 35043 Marburg, Germany.
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