1
|
Wu L, Zhang Y, Hong X, Wu M, Wang L, Yan X. Deciphering the Relationship between Cell Growth and Cell Cycle in Individual Escherichia coli Cells by Flow Cytometry. Anal Chem 2024. [PMID: 39015018 DOI: 10.1021/acs.analchem.4c02058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Accurate coordination of chromosome replication and cell division is essential for cellular processes, yet the regulatory mechanisms governing the bacterial cell cycle remain contentious. The lack of quantitative data connecting key cell cycle players at the single-cell level across large samples hinders consensus. Employing high-throughput flow cytometry, we quantitatively correlated the expression levels of key cell cycle proteins (FtsZ, MreB, and DnaA) with DNA content in individual bacteria. Our findings reveal distinct correlations depending on the chromosome number (CN), specifically whether CN ≤2 or ≥4, unveiling a mixed regulatory scenario in populations where CN of 2 or 4 coexist. We observed function-dependent regulations for these key proteins across nonoverlapping division cycles and various nutrient conditions. Notably, a logarithmic relationship between total protein content and replication origin number across nutrient conditions suggests a unified mechanism governing cell cycle progression, confirming the applicability of Schaechter's growth law to cells with CN ≥4. For the first time, we established a proportional relationship between the synthesis rates of key cell cycle proteins and chromosome dynamics in cells with CN ≥4. Drug experiments highlighted CN 2 and 4 as pivotal turning points influencing cellular resource allocation. This high-throughput, single-cell analysis provides interconnected quantitative insights into key molecular events, facilitating a predictive understanding of the relationship between cell growth and cell cycle.
Collapse
Affiliation(s)
- Lina Wu
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Yuzhen Zhang
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Xinyi Hong
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Mingkai Wu
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Liangan Wang
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| | - Xiaomei Yan
- Department of Chemical Biology, MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
| |
Collapse
|
2
|
Nieto C, Vargas-García CA, Pedraza JM, Singh A. Mechanisms of cell size regulation in slow-growing Escherichia coli cells: discriminating models beyond the adder. NPJ Syst Biol Appl 2024; 10:61. [PMID: 38811603 PMCID: PMC11137094 DOI: 10.1038/s41540-024-00383-z] [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: 09/11/2023] [Accepted: 05/09/2024] [Indexed: 05/31/2024] Open
Abstract
Under ideal conditions, Escherichia coli cells divide after adding a fixed cell size, a strategy known as the adder. This concept applies to various microbes and is often explained as the division that occurs after a certain number of stages, associated with the accumulation of precursor proteins at a rate proportional to cell size. However, under poor media conditions, E. coli cells exhibit a different size regulation. They are smaller and follow a sizer-like division strategy where the added size is inversely proportional to the size at birth. We explore three potential causes for this deviation: degradation of the precursor protein and two models where the propensity for accumulation depends on the cell size: a nonlinear accumulation rate, and accumulation starting at a threshold size termed the commitment size. These models fit the mean trends but predict different distributions given the birth size. To quantify the precision of the models to explain the data, we used the Akaike information criterion and compared them to open datasets of slow-growing E. coli cells in different media. We found that none of the models alone can consistently explain the data. However, the degradation model better explains the division strategy when cells are larger, whereas size-related models (power-law and commitment size) account for smaller cells. Our methodology proposes a data-based method in which different mechanisms can be tested systematically.
Collapse
Affiliation(s)
- César Nieto
- Department of Physics, Universidad de los Andes, Bogotá, Colombia
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE, 19716, USA
| | | | | | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, DE, 19716, USA.
- Department of Electrical and Computer Engineering, Biomedical Engineering, Mathematical Sciences, Center of Bioinformatic and Computational Biology, University of Delaware, Newark, DE, 19716, USA.
| |
Collapse
|
3
|
Govers SK, Campos M, Tyagi B, Laloux G, Jacobs-Wagner C. Apparent simplicity and emergent robustness in the control of the Escherichia coli cell cycle. Cell Syst 2024; 15:19-36.e5. [PMID: 38157847 DOI: 10.1016/j.cels.2023.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/15/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024]
Abstract
To examine how bacteria achieve robust cell proliferation across diverse conditions, we developed a method that quantifies 77 cell morphological, cell cycle, and growth phenotypes of a fluorescently labeled Escherichia coli strain and >800 gene deletion derivatives under multiple nutrient conditions. This approach revealed extensive phenotypic plasticity and deviating mutant phenotypes were often nutrient dependent. From this broad phenotypic landscape emerged simple and robust unifying rules (laws) that connect DNA replication initiation, nucleoid segregation, FtsZ ring formation, and cell constriction to specific aspects of cell size (volume, length, or added length) at the population level. Furthermore, completion of cell division followed the initiation of cell constriction after a constant time delay across strains and nutrient conditions, identifying cell constriction as a key control point for cell size determination. Our work provides a population-level description of the governing principles by which E. coli integrates cell cycle processes and growth rate with cell size to achieve its robust proliferative capability. A record of this paper's transparent peer review process is included in the supplemental information.
Collapse
Affiliation(s)
- Sander K Govers
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; de Duve Institute, UCLouvain, Brussels, Belgium; Department of Biology, KU Leuven, Leuven, Belgium
| | - Manuel Campos
- Centre de Biologie Intégrative de Toulouse, Laboratoire de Microbiologie et Génétique Moléculaires, Université de Toulouse, Toulouse, France
| | - Bhavyaa Tyagi
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | - Christine Jacobs-Wagner
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA; Sarafan Chemistry, Engineering Medicine for Human Health Institute, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
4
|
Morrison JJ, Camberg JL. Building the Bacterial Divisome at the Septum. Subcell Biochem 2024; 104:49-71. [PMID: 38963483 DOI: 10.1007/978-3-031-58843-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Across living organisms, division is necessary for cell survival and passing heritable information to the next generation. For this reason, cell division is highly conserved among eukaryotes and prokaryotes. Among the most highly conserved cell division proteins in eukaryotes are tubulin and actin. Tubulin polymerizes to form microtubules, which assemble into cytoskeletal structures in eukaryotes, such as the mitotic spindle that pulls chromatids apart during mitosis. Actin polymerizes to form a morphological framework for the eukaryotic cell, or cytoskeleton, that undergoes reorganization during mitosis. In prokaryotes, two of the most highly conserved cell division proteins are the tubulin homolog FtsZ and the actin homolog FtsA. In this chapter, the functions of the essential bacterial cell division proteins FtsZ and FtsA and their roles in assembly of the divisome at the septum, the site of cell division, will be discussed. In most bacteria, including Escherichia coli, the tubulin homolog FtsZ polymerizes at midcell, and this step is crucial for recruitment of many other proteins to the division site. For this reason, both FtsZ abundance and polymerization are tightly regulated by a variety of proteins. The actin-like FtsA protein polymerizes and tethers FtsZ polymers to the cytoplasmic membrane. Additionally, FtsA interacts with later stage cell division proteins, which are essential for division and for building the new cell wall at the septum. Recent studies have investigated how actin-like polymerization of FtsA on the lipid membrane may impact division, and we will discuss this and other ways that division in bacteria is regulated through FtsZ and FtsA.
Collapse
Affiliation(s)
- Josiah J Morrison
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA
| | - Jodi L Camberg
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA.
| |
Collapse
|
5
|
Cameron TA, Margolin W. Insights into the assembly and regulation of the bacterial divisome. Nat Rev Microbiol 2024; 22:33-45. [PMID: 37524757 PMCID: PMC11102604 DOI: 10.1038/s41579-023-00942-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2023] [Indexed: 08/02/2023]
Abstract
The ability to split one cell into two is fundamental to all life, and many bacteria can accomplish this feat several times per hour with high accuracy. Most bacteria call on an ancient homologue of tubulin, called FtsZ, to localize and organize the cell division machinery, the divisome, into a ring-like structure at the cell midpoint. The divisome includes numerous other proteins, often including an actin homologue (FtsA), that interact with each other at the cytoplasmic membrane. Once assembled, the protein complexes that comprise the dynamic divisome coordinate membrane constriction with synthesis of a division septum, but only after overcoming checkpoints mediated by specialized protein-protein interactions. In this Review, we summarize the most recent evidence showing how the divisome proteins of Escherichia coli assemble at the cell midpoint, interact with each other and regulate activation of septum synthesis. We also briefly discuss the potential of divisome proteins as novel antibiotic targets.
Collapse
Affiliation(s)
- Todd A Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX, USA.
| |
Collapse
|
6
|
Nieto C, Täuber S, Blöbaum L, Vahdat Z, Grünberger A, Singh A. Coupling Cell Size Regulation and Proliferation Dynamics of C. glutamicum Reveals Cell Division Based on Surface Area. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.26.573217. [PMID: 38234762 PMCID: PMC10793411 DOI: 10.1101/2023.12.26.573217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Single cells actively coordinate growth and division to regulate their size, yet how this size homeostasis at the single-cell level propagates over multiple generations to impact clonal expansion remains fundamentally unexplored. Classical timer models for cell proliferation (where the duration of the cell cycle is an independent variable) predict that the stochastic variation in colony size will increase monotonically over time. In stark contrast, implementing size control according to adder strategy (where on average a fixed size added from cell birth to division) leads to colony size variations that eventually decay to zero. While these results assume a fixed size of the colony-initiating progenitor cell, further analysis reveals that the magnitude of the intercolony variation in population number is sensitive to heterogeneity in the initial cell size. We validate these predictions by tracking the growth of isogenic microcolonies of Corynebacterium glutamicum in microfluidic chambers. Approximating their cell shape to a capsule, we observe that the degree of random variability in cell size is different depending on whether the cell size is quantified as per length, surface area, or volume, but size control remains an adder regardless of these size metrics. A comparison of the observed variability in the colony population with the predictions suggests that proliferation matches better with a cell division based on the cell surface. In summary, our integrated mathematical-experimental approach bridges the paradigms of single-cell size regulation and clonal expansion at the population levels. This innovative approach provides elucidation of the mechanisms of size homeostasis from the stochastic dynamics of colony size for rod-shaped microbes.
Collapse
Affiliation(s)
- César Nieto
- Department of Electrical and Computing Engineering, University of Delaware. Newark, DE 19716, USA
| | - Sarah Täuber
- CeBiTec, Bielefeld University. Bielefeld, Germany
- Multiscale Bioengineering, Technical Faculty, Bielefeld University. Bielefeld, Germany
| | - Luisa Blöbaum
- CeBiTec, Bielefeld University. Bielefeld, Germany
- Multiscale Bioengineering, Technical Faculty, Bielefeld University. Bielefeld, Germany
| | - Zahra Vahdat
- Department of Electrical and Computing Engineering, University of Delaware. Newark, DE 19716, USA
| | - Alexander Grünberger
- CeBiTec, Bielefeld University. Bielefeld, Germany
- Multiscale Bioengineering, Technical Faculty, Bielefeld University. Bielefeld, Germany
- Institute of Process Engineering in Life Sciences: Microsystems in Bioprocess Engineering, Karlsruhe Institute of Technology. Karlsruhe, Germany
| | - Abhyudai Singh
- Department of Electrical and Computing Engineering, University of Delaware. Newark, DE 19716, USA
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716 USA
| |
Collapse
|
7
|
Anderson SE, Vadia SE, McKelvy J, Levin PA. The transcription factor DksA exerts opposing effects on cell division depending on the presence of ppGpp. mBio 2023; 14:e0242523. [PMID: 37882534 PMCID: PMC10746185 DOI: 10.1128/mbio.02425-23] [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: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 10/27/2023] Open
Abstract
IMPORTANCE Cell division is a key step in the bacterial lifecycle that must be appropriately regulated to ensure survival. This work identifies the alarmone (p)ppGpp (ppGpp) as a general regulator of cell division, extending our understanding of the role of ppGpp beyond a signal for starvation and other stress. Even in nutrient-replete conditions, basal levels of ppGpp are essential for division to occur appropriately and for cell size to be maintained. This study establishes ppGpp as a "switch" that controls whether the transcription factor DksA behaves as a division activator or inhibitor. This unexpected finding enhances our understanding of the complex regulatory mechanisms employed by bacteria to coordinate division with diverse aspects of cell growth and stress response. Because division is an essential process, a better understanding of the mechanisms governing the assembly and activation of the division machinery could contribute to the development of novel therapeutics to treat bacterial infections.
Collapse
Affiliation(s)
- Sarah E. Anderson
- Department of Biology, Washington University in St. Louis, Saint Louis, Missouri, USA
| | - Stephen E. Vadia
- Department of Biology, Washington University in St. Louis, Saint Louis, Missouri, USA
| | - Jane McKelvy
- Department of Biology, Washington University in St. Louis, Saint Louis, Missouri, USA
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, Saint Louis, Missouri, USA
| |
Collapse
|
8
|
Nieto C, Vargas-García C, Pedraza JM, Singh A. Mechanisms of Cell Size Regulation in Slow-Growing Escherichia coli Cells: Discriminating Models Beyond the Adder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557238. [PMID: 37745550 PMCID: PMC10515837 DOI: 10.1101/2023.09.11.557238] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Under ideal conditions, Escherichia coli cells divide after adding a fixed cell size, a strategy known as the adder. This concept applies to various microbes and is often explained as the division that occurs after a certain number of stages, associated with the accumulation of precursor proteins at a rate proportional to cell size. However, under poor media conditions, E. coli cells exhibit a different size regulation. They are smaller and follow a sizer-like division strategy where the added size is inversely proportional to the size at birth. We explore three potential causes for this deviation: precursor protein degradation, nonlinear accumulation rate, and a threshold size termed the commitment size. These models fit mean trends but predict different distributions given the birth size. To validate these models, we used the Akaike information criterion and compared them to open datasets of slow-growing E. coli cells in different media. the degradation model could explain the division strategy for media where cells are larger, while the commitment size model could account for smaller cells. The power-law model, finally, better fits the data at intermediate regimes.
Collapse
Affiliation(s)
- César Nieto
- Department of Physics, Universidad de los Andes, Bogotá, Colombia
- Department of Electrical and Computing Engineering, University of Delaware. Newark, DE 19716, USA
| | - César Vargas-García
- AGROSAVIA Corporación Colombiana de Investigación Agropecuaria. Mosquera. Colombia
| | | | - Abhyudai Singh
- Department of Electrical and Computing Engineering, University of Delaware. Newark, DE 19716, USA
| |
Collapse
|
9
|
Anderson SE, Vadia SE, McKelvy J, Levin PA. The transcription factor DksA exerts opposing effects on cell division depending on the presence of ppGpp. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.15.540843. [PMID: 37293059 PMCID: PMC10245573 DOI: 10.1101/2023.05.15.540843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bacterial cell size is a multifactorial trait that is influenced by variables including nutritional availability and the timing of cell division. Prior work revealed a negative correlation between the alarmone (p)ppGpp (ppGpp) and cell length in Escherichia coli , suggesting that ppGpp may promote assembly of the division machinery (divisome) and cytokinesis in this organism. To clarify this counterintuitive connection between a starvation induced stress response effector and cell proliferation, we undertook a systematic analysis of growth and division in E. coli cells defective in ppGpp synthesis and/or engineered to overproduce the alarmone. Our data indicate that ppGpp acts indirectly on divisome assembly through its role as a global mediator of transcription. Loss of either ppGpp (ppGpp 0 ) or the ppGpp-associated transcription factor DksA led to increased average length, with ppGpp 0 mutants also exhibiting a high frequency of extremely long filamentous cells. Using heat-sensitive division mutants and fluorescently labeled division proteins, we confirmed that ppGpp and DksA are cell division activators. We found that ppGpp and DksA regulate division through their effects on transcription, although the lack of known division genes or regulators in available transcriptomics data strongly suggests that this regulation is indirect. Surprisingly, we also found that DksA inhibits division in ppGpp 0 cells, contrary to its role in a wild-type background. We propose that the ability of ppGpp to switch DksA from a division inhibitor to a division activator helps tune cell length across different concentrations of ppGpp. Importance Cell division is a key step in the bacterial lifecycle that must be appropriately regulated to ensure survival. This work identifies the alarmone ppGpp as a general regulator of cell division, extending our understanding of the role of ppGpp beyond a signal for starvation and other stress. Even in nutrient replete conditions, basal levels of ppGpp are essential for division to occur appropriately and for cell size to be maintained. This study establishes ppGpp as a "switch" that controls whether the transcription factor DksA behaves as a division activator or inhibitor. This unexpected finding enhances our understanding of the complex regulatory mechanisms employed by bacteria to coordinate division with diverse aspects of cell growth and stress response. Because division is an essential process, a better understanding the mechanisms governing assembly and activation of the division machinery could contribute to the development of novel therapeutics to treat bacterial infections.
Collapse
|
10
|
Kratz JC, Banerjee S. Dynamic proteome trade-offs regulate bacterial cell size and growth in fluctuating nutrient environments. Commun Biol 2023; 6:486. [PMID: 37147517 PMCID: PMC10163005 DOI: 10.1038/s42003-023-04865-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 04/24/2023] [Indexed: 05/07/2023] Open
Abstract
Bacteria dynamically regulate cell size and growth to thrive in changing environments. While previous studies have characterized bacterial growth physiology at steady-state, a quantitative understanding of bacterial physiology in time-varying environments is lacking. Here we develop a quantitative theory connecting bacterial growth and division rates to proteome allocation in time-varying nutrient environments. In such environments, cell size and growth are regulated by trade-offs between prioritization of biomass accumulation or division, resulting in decoupling of single-cell growth rate from population growth rate. Specifically, bacteria transiently prioritize biomass accumulation over production of division machinery during nutrient upshifts, while prioritizing division over growth during downshifts. When subjected to pulsatile nutrient concentration, we find that bacteria exhibit a transient memory of previous metabolic states due to the slow dynamics of proteome reallocation. This allows for faster adaptation to previously seen environments and results in division control which is dependent on the time-profile of fluctuations.
Collapse
Affiliation(s)
- Josiah C Kratz
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
11
|
Westlund E, Bergenstråle A, Pokhrel A, Chan H, Skoglund U, Daley DO, Söderström B. Application of nanotags and nanobodies for live cell single-molecule imaging of the Z-ring in Escherichia coli. Curr Genet 2023; 69:153-163. [PMID: 37022498 PMCID: PMC10163087 DOI: 10.1007/s00294-023-01266-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/22/2023] [Accepted: 03/24/2023] [Indexed: 04/07/2023]
Abstract
Understanding where proteins are localized in a bacterial cell is essential for understanding their function and regulation. This is particularly important for proteins that are involved in cell division, which localize at the division septum and assemble into highly regulated complexes. Current knowledge of these complexes has been greatly facilitated by super-resolution imaging using fluorescent protein fusions. Herein, we demonstrate with FtsZ that single-molecule PALM images can be obtained in-vivo using a genetically fused nanotag (ALFA), and a corresponding nanobody fused to mEos3.2. The methodology presented is applicable to other bacterial proteins.
Collapse
Affiliation(s)
- Emma Westlund
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Axel Bergenstråle
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Alaska Pokhrel
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Helena Chan
- Structural Cellular Biology Unit, Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Ulf Skoglund
- Structural Cellular Biology Unit, Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Daniel O Daley
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden.
| | - Bill Söderström
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| |
Collapse
|
12
|
Tveit AT, Söllinger A, Rainer EM, Didriksen A, Hestnes AG, Motleleng L, Hellinger HJ, Rattei T, Svenning MM. Thermal acclimation of methanotrophs from the genus Methylobacter. THE ISME JOURNAL 2023; 17:502-513. [PMID: 36650275 PMCID: PMC10030640 DOI: 10.1038/s41396-023-01363-7] [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: 09/15/2022] [Revised: 12/30/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023]
Abstract
Methanotrophs oxidize most of the methane (CH4) produced in natural and anthropogenic ecosystems. Often living close to soil surfaces, these microorganisms must frequently adjust to temperature change. While many environmental studies have addressed temperature effects on CH4 oxidation and methanotrophic communities, there is little knowledge about the physiological adjustments that underlie these effects. We have studied thermal acclimation in Methylobacter, a widespread, abundant, and environmentally important methanotrophic genus. Comparisons of growth and CH4 oxidation kinetics at different temperatures in three members of the genus demonstrate that temperature has a strong influence on how much CH4 is consumed to support growth at different CH4 concentrations. However, the temperature effect varies considerably between species, suggesting that how a methanotrophic community is composed influences the temperature effect on CH4 uptake. To understand thermal acclimation mechanisms widely we carried out a transcriptomics experiment with Methylobacter tundripaludum SV96T. We observed, at different temperatures, how varying abundances of transcripts for glycogen and protein biosynthesis relate to cellular glycogen and ribosome concentrations. Our data also demonstrated transcriptional adjustment of CH4 oxidation, oxidative phosphorylation, membrane fatty acid saturation, cell wall composition, and exopolysaccharides between temperatures. In addition, we observed differences in M. tundripaludum SV96T cell sizes at different temperatures. We conclude that thermal acclimation in Methylobacter results from transcriptional adjustment of central metabolism, protein biosynthesis, cell walls and storage. Acclimation leads to large shifts in CH4 consumption and growth efficiency, but with major differences between species. Thus, our study demonstrates that physiological adjustments to temperature change can substantially influence environmental CH4 uptake rates and that consideration of methanotroph physiology might be vital for accurate predictions of warming effects on CH4 emissions.
Collapse
Affiliation(s)
- Alexander T Tveit
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway.
| | - Andrea Söllinger
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Edda Marie Rainer
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Alena Didriksen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anne Grethe Hestnes
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Liabo Motleleng
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Hans-Jörg Hellinger
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
- University of Vienna, Doctoral School in Microbiology and Environmental Science, Vienna, Austria
| | - Thomas Rattei
- University of Vienna, Centre for Microbiology and Environmental Systems Science, Vienna, Austria
| | - Mette M Svenning
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| |
Collapse
|
13
|
Godino E, Danelon C. Gene-Directed FtsZ Ring Assembly Generates Constricted Liposomes with Stable Membrane Necks. Adv Biol (Weinh) 2023; 7:e2200172. [PMID: 36593513 DOI: 10.1002/adbi.202200172] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/15/2022] [Indexed: 01/04/2023]
Abstract
Mimicking bacterial cell division in well-defined cell-free systems has the potential to elucidate the minimal set of proteins required for cytoskeletal formation, membrane constriction, and final abscission. Membrane-anchored FtsZ polymers are often regarded as a sufficient system to realize this chain of events. By using purified FtsZ and its membrane-binding protein FtsA or the gain-of-function mutant FtsA* expressed in PURE (Protein synthesis Using Reconstituted Elements) from a DNA template, it is shown in this study that cytoskeletal structures are formed, and yield constricted liposomes exhibiting various morphologies. However, the resulting buds remain attached to the parental liposome by a narrow membrane neck. No division events can be monitored even after long-time tracking by fluorescence microscopy, nor when the osmolarity of the external solution is increased. The results provide evidence that reconstituted FtsA-FtsZ proto-rings coating the membrane necks are too stable to enable abscission. The prospect of combining a DNA-encoded FtsZ system with assisting mechanisms to achieve synthetic cell division is discussed.
Collapse
Affiliation(s)
- Elisa Godino
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629HZ, The Netherlands
| | - Christophe Danelon
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2629HZ, The Netherlands
| |
Collapse
|
14
|
Kellogg DR, Levin PA. Nutrient availability as an arbiter of cell size. Trends Cell Biol 2022; 32:908-919. [PMID: 35851491 PMCID: PMC9588502 DOI: 10.1016/j.tcb.2022.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/07/2022] [Accepted: 06/16/2022] [Indexed: 01/21/2023]
Abstract
Pioneering work carried out over 60 years ago discovered that bacterial cell size is proportional to the growth rate set by nutrient availability. This relationship is traditionally referred to as the 'growth law'. Subsequent studies revealed the growth law to hold across all orders of life, a remarkable degree of conservation. However, recent work suggests the relationship between growth rate, nutrients, and cell size is far more complicated and less deterministic than originally thought. Focusing on bacteria and yeast, here we review efforts to understand the molecular mechanisms underlying the relationship between growth rate and cell size.
Collapse
Affiliation(s)
- Douglas R Kellogg
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St Louis, MO 63130, USA; Center for Science & Engineering of Living Systems (CSELS), McKelvey School of Engineering, Washington University in St Louis, St Louis, MO 63130, USA.
| |
Collapse
|
15
|
Männik J, Pichoff S, Lutkenhaus J, Männik J. Cell Cycle-Dependent Recruitment of FtsN to the Divisome in Escherichia coli. mBio 2022; 13:e0201722. [PMID: 35968943 PMCID: PMC9426451 DOI: 10.1128/mbio.02017-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 12/13/2022] Open
Abstract
Cell division in Escherichia coli starts with the formation of an FtsZ protofilament network at midcell, the Z ring. However, only after a considerable lag period does the cell start to form a midcell constriction. The onset of constriction depends upon the arrival of so-called late divisome proteins, among which, FtsN is the last essential one. The timing and dependency of FtsN arrival to the divisome, along with genetic evidence, suggests it triggers cell division. In this study, we used high-throughput fluorescence microscopy to determine the arrival of FtsN and the early divisome protein ZapA to midcell at a single-cell level during the cell cycle. Our data show while the recruitment of ZapA/FtsZ is gradual in the cell cycle, recruitment of FtsN is rapid and begins at about the onset of constriction. At this time, the fraction of ZapA/FtsZ in the Z ring approaches its peak value. We also find a second increase in FtsN recruitment to the divisome, which begins once the amount of ZapA/FtsZ at midcell starts decreasing. Increasing hypermorphic FtsA* (FtsA R286W), but not FtsA, accelerates FtsN recruitment but not constriction. This finding is consistent with FtsA* recruiting FtsN with some other divisome component being rate-limiting for constriction under these conditions. Finally, our data support the recently proposed idea that ZapA/FtsZ and FtsN are part of physically separate complexes in midcell throughout the whole septation process. IMPORTANCE Cell division in most bacteria starts with the formation of an FtsZ protofilament network at midcell, the Z ring. However, cells only start to constrict after a considerable lag. A factor thought to trigger the onset of constriction in Escherichia coli is FtsN, which is the last essential protein to be recruited to the Z ring. Using a high-throughput quantitative fluorescence microscopy, we determine the cell cycle-dependent recruitment of FtsN to the Z ring. Our data show rapid accumulation of FtsN to the Z ring about a quarter of the cell cycle after the formation of the Z ring. This initial wave is followed by another increase in FtsN recruitment once the FtsZ protofilament network starts to disassemble. The presence of FtsA* accelerates FtsN recruitment to the Z ring but does not lead to earlier constrictions. Our data furthermore suggest FtsZ and FtsN are part of physically separate complexes throughout the division process.
Collapse
Affiliation(s)
- Jaana Männik
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, USA
| | - Sebastien Pichoff
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Joe Lutkenhaus
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Jaan Männik
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee, USA
| |
Collapse
|
16
|
Viola MG, Perdikari TM, Trebino CE, Rahmani N, Mathews KL, Pena CM, Chua XY, Xuan B, LaBreck CJ, Fawzi NL, Camberg JL. An enhancer sequence in the intrinsically disordered region of FtsZ promotes polymer-guided substrate processing by ClpXP protease. Protein Sci 2022; 31:e4306. [PMID: 35481648 PMCID: PMC8996474 DOI: 10.1002/pro.4306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 11/09/2022]
Abstract
The essential bacterial division protein in Escherichia coli, FtsZ, assembles into the FtsZ-ring at midcell and recruits other proteins to the division site to promote septation. A region of the FtsZ amino acid sequence that links the conserved polymerization domain to a C-terminal protein interaction site was predicted to be intrinsically disordered and has been implicated in modulating spacing and architectural arrangements of FtsZ filaments. While the majority of cell division proteins that directly bind to FtsZ engage either the polymerization domain or the C-terminal interaction site, ClpX, the recognition and unfolding component of the bacterial ClpXP proteasome, has a secondary interaction with the predicted intrinsically disordered region (IDR) of FtsZ when FtsZ is polymerized. Here, we use NMR spectroscopy and reconstituted degradation reactions in vitro to demonstrate that this linker region is indeed disordered in solution and, further, that amino acids in the IDR of FtsZ enhance the degradation in polymer-guided interactions.
Collapse
Affiliation(s)
- Marissa G. Viola
- Department of Cell and Molecular BiologyUniversity of Rhode IslandKingstonRhode IslandUSA
| | | | - Catherine E. Trebino
- Department of Cell and Molecular BiologyUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Negar Rahmani
- Department of Cell and Molecular BiologyUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Kaylee L. Mathews
- Molecular Biology, Cell Biology, & Biochemistry Graduate ProgramBrown UniversityProvidenceRhode IslandUSA
| | - Carolina Mejia Pena
- Molecular Biology, Cell Biology, & Biochemistry Graduate ProgramBrown UniversityProvidenceRhode IslandUSA
| | - Xien Yu Chua
- Department of Molecular Pharmacology, Physiology & BiotechnologyBrown UniversityProvidenceRhode IslandUSA
| | - Botai Xuan
- Department of Molecular Pharmacology, Physiology & BiotechnologyBrown UniversityProvidenceRhode IslandUSA
| | - Christopher J. LaBreck
- Department of Cell and Molecular BiologyUniversity of Rhode IslandKingstonRhode IslandUSA
| | - Nicolas L. Fawzi
- Department of Molecular Pharmacology, Physiology & BiotechnologyBrown UniversityProvidenceRhode IslandUSA
| | - Jodi L. Camberg
- Department of Cell and Molecular BiologyUniversity of Rhode IslandKingstonRhode IslandUSA
| |
Collapse
|
17
|
Nuwong W, Kittiwongwattana C. Validation of reference genes for the normalization of RT-qPCR gene expression in Bacillus siamensis 1021 grown in different culture media. IRANIAN JOURNAL OF MICROBIOLOGY 2022; 14:194-202. [PMID: 35765559 PMCID: PMC9168254 DOI: 10.18502/ijm.v14i2.9188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background and Objectives House-keeping genes are generally selected as reference genes in gene expression analysis. However, some genes may not be stably expressed across all experimental conditions. Thus, this study aimed to validate seven house-keeping genes for gene expression analysis in Bacillus siamensis 1021. Materials and Methods Strain 1021 was grown in potato dextrose broth, nutrient broth and mineral salt medium. Reverse-transcription quantitative PCR was used to determine Cq values of seven reference genes including gyrA, gyrB, ssb and dnaB, rpsU, gat_Yqey and udp in these media. Expression stability of these genes was analyzed, using geNorm and Normfinder applications. The target gene ftsZ was used for assessment of the best candidate genes. Results Based on geNorm and Normfinder, ssb was the most-stably expressed gene, while udp was the least-stably expressed gene. Pairwise variation indicated the combination of ssb, gyrA, gyrB and gatB_Yqey was suitable for the normalization of ftsZ expression. ftsZ expression in potato dextrose broth and mineral salt medium was higher than that in nutrient broth. In contrast, the normalization against udp resulted in an under- and overestimation of ftsZ expression in potato dextrose broth and mineral salt medium, respectively. Conclusion The combination of ssb, gyrA, gyrB and gatB_Yqey was the best candidate for normalization of target gene expression in B. siamensis 1021 in these media. This study emphasized the significance of reference gene validation for gene expression analysis and provided a guideline for future gene expression studies in B. siamensis.
Collapse
Affiliation(s)
- Warinya Nuwong
- Department of Biology, School of Science, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand
| | - Chokchai Kittiwongwattana
- Department of Biology, School of Science, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand
| |
Collapse
|
18
|
Söllinger A, Séneca J, Borg Dahl M, Motleleng LL, Prommer J, Verbruggen E, Sigurdsson BD, Janssens I, Peñuelas J, Urich T, Richter A, Tveit AT. Down-regulation of the bacterial protein biosynthesis machinery in response to weeks, years, and decades of soil warming. SCIENCE ADVANCES 2022; 8:eabm3230. [PMID: 35333567 PMCID: PMC8956259 DOI: 10.1126/sciadv.abm3230] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 02/03/2022] [Indexed: 05/26/2023]
Abstract
How soil microorganisms respond to global warming is key to infer future soil-climate feedbacks, yet poorly understood. Here, we applied metatranscriptomics to investigate microbial physiological responses to medium-term (8 years) and long-term (>50 years) subarctic grassland soil warming of +6°C. Besides indications for a community-wide up-regulation of centralmetabolic pathways and cell replication, we observed a down-regulation of the bacterial protein biosynthesis machinery in the warmed soils, coinciding with a lower microbial biomass, RNA, and soil substrate content. We conclude that permanently accelerated reaction rates at higher temperatures and reduced substrate concentrations result in cellular reduction of ribosomes, the macromolecular complexes carrying out protein biosynthesis. Later efforts to test this, including a short-term warming experiment (6 weeks, +6°C), further supported our conclusion. Down-regulating the protein biosynthesis machinery liberates energy and matter, allowing soil bacteria to maintain high metabolic activities and cell division rates even after decades of warming.
Collapse
Affiliation(s)
- Andrea Söllinger
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Joana Séneca
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Mathilde Borg Dahl
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Liabo L. Motleleng
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Judith Prommer
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | | | | | | | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Barcelona, Spain
- CREAF, Barcelona, Spain
| | - Tim Urich
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Andreas Richter
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Alexander T. Tveit
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| |
Collapse
|
19
|
Coupling between DNA replication, segregation, and the onset of constriction in Escherichia coli. Cell Rep 2022; 38:110539. [PMID: 35320717 PMCID: PMC9003928 DOI: 10.1016/j.celrep.2022.110539] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 10/01/2021] [Accepted: 02/25/2022] [Indexed: 11/24/2022] Open
Abstract
Escherichia coli cell cycle features two critical cell-cycle checkpoints: initiation of replication and the onset of constriction. While the initiation of DNA replication has been extensively studied, it is less clear what triggers the onset of constriction and when exactly it occurs during the cell cycle. Here, using high-throughput fluorescence microscopy in microfluidic devices, we determine the timing for the onset of constriction relative to the replication cycle in different growth rates. Our single-cell data and modeling indicate that the initiation of constriction is coupled to replication-related processes in slow growth conditions. Furthermore, our data suggest that this coupling involves the mid-cell chromosome blocking the onset of constriction via some form of nucleoid occlusion occurring independently of SlmA and the Ter linkage proteins. This work highlights the coupling between replication and division cycles and brings up a new nucleoid mediated control mechanism in E. coli. Using high-throughput microscopy, Tiruvadi-Krishnan et al. determine timings for critical cell-cycle checkpoints related to division and replication in Escherichia coli. The data, combined with cell-cycle modeling, show that the onset of constriction is blocked by the mid-cell nucleoid. In slow-growth conditions, the blockage is limiting for cell division.
Collapse
|
20
|
Salinas-Almaguer S, Mell M, Almendro-Vedia VG, Calero M, Robledo-Sánchez KCM, Ruiz-Suarez C, Alarcón T, Barrio RA, Hernández-Machado A, Monroy F. Membrane rigidity regulates E. coli proliferation rates. Sci Rep 2022; 12:933. [PMID: 35042922 PMCID: PMC8766614 DOI: 10.1038/s41598-022-04970-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 01/04/2022] [Indexed: 12/23/2022] Open
Abstract
Combining single cell experiments, population dynamics and theoretical methods of membrane mechanics, we put forward that the rate of cell proliferation in E. coli colonies can be regulated by modifiers of the mechanical properties of the bacterial membrane. Bacterial proliferation was modelled as mediated by cell division through a membrane constriction divisome based on FtsZ, a mechanically competent protein at elastic interaction against membrane rigidity. Using membrane fluctuation spectroscopy in the single cells, we revealed either membrane stiffening when considering hydrophobic long chain fatty substances, or membrane softening if short-chained hydrophilic molecules are used. Membrane stiffeners caused hindered growth under normal division in the microbial cultures, as expected for membrane rigidification. Membrane softeners, however, altered regular cell division causing persistent microbes that abnormally grow as long filamentous cells proliferating apparently faster. We invoke the concept of effective growth rate under the assumption of a heterogeneous population structure composed by distinguishable individuals with different FtsZ-content leading the possible forms of cell proliferation, from regular division in two normal daughters to continuous growing filamentation and budding. The results settle altogether into a master plot that captures a universal scaling between membrane rigidity and the divisional instability mediated by FtsZ at the onset of membrane constriction.
Collapse
Affiliation(s)
- Samuel Salinas-Almaguer
- Centro de Investigación y de Estudios Avanzados, Unidad Monterrey, Vía del Conocimiento 201, PIIT, 66600, Apodaca, NL, Mexico
- Departamento de Química Física, Universidad Complutense de Madrid, Av. Complutense S/N, 28040, Madrid, Spain
| | - Michael Mell
- Departamento de Química Física, Universidad Complutense de Madrid, Av. Complutense S/N, 28040, Madrid, Spain
| | - Victor G Almendro-Vedia
- Departamento de Química Física, Universidad Complutense de Madrid, Av. Complutense S/N, 28040, Madrid, Spain
| | - Macarena Calero
- Departamento de Química Física, Universidad Complutense de Madrid, Av. Complutense S/N, 28040, Madrid, Spain
- Translational Biophysics, Instituto de Investigación Sanitaria Hospital Doce de Octubre (IMAS12), Av. Andalucía S/N, 28041, Madrid, Spain
| | | | - Carlos Ruiz-Suarez
- Centro de Investigación y de Estudios Avanzados, Unidad Monterrey, Vía del Conocimiento 201, PIIT, 66600, Apodaca, NL, Mexico
| | - Tomás Alarcón
- ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
- Centre de Recerca Matemàtica, Edifici C, Campus de Bellaterra, 08193, Bellaterra, Barcelona, Spain
- Departament de Matemàtiques, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
- Barcelona Graduate School of Mathematics (BGSMath), Barcelona, Spain
| | - Rafael A Barrio
- Instituto de Fisica, U.N.A.M., Apartado Postal 20-364, 01000, Mexico, D.F., Mexico
| | - Aurora Hernández-Machado
- Centre de Recerca Matemàtica, Edifici C, Campus de Bellaterra, 08193, Bellaterra, Barcelona, Spain.
- Departament Fisica de la Materia Condensada, Facultat de Fisica, Universitat de Barcelona, Diagonal 645, 08028, Barcelona, Spain.
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain.
| | - Francisco Monroy
- Departamento de Química Física, Universidad Complutense de Madrid, Av. Complutense S/N, 28040, Madrid, Spain.
- Translational Biophysics, Instituto de Investigación Sanitaria Hospital Doce de Octubre (IMAS12), Av. Andalucía S/N, 28041, Madrid, Spain.
| |
Collapse
|
21
|
Levin PA, Janakiraman A. Localization, Assembly, and Activation of the Escherichia coli Cell Division Machinery. EcoSal Plus 2021; 9:eESP00222021. [PMID: 34910577 PMCID: PMC8919703 DOI: 10.1128/ecosalplus.esp-0022-2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 11/14/2021] [Indexed: 01/01/2023]
Abstract
Decades of research, much of it in Escherichia coli, have yielded a wealth of insight into bacterial cell division. Here, we provide an overview of the E. coli division machinery with an emphasis on recent findings. We begin with a short historical perspective into the discovery of FtsZ, the tubulin homolog that is essential for division in bacteria and archaea. We then discuss assembly of the divisome, an FtsZ-dependent multiprotein platform, at the midcell septal site. Not simply a scaffold, the dynamic properties of polymeric FtsZ ensure the efficient and uniform synthesis of septal peptidoglycan. Next, we describe the remodeling of the cell wall, invagination of the cell envelope, and disassembly of the division apparatus culminating in scission of the mother cell into two daughter cells. We conclude this review by highlighting some of the open questions in the cell division field, emphasizing that much remains to be discovered, even in an organism as extensively studied as E. coli.
Collapse
Affiliation(s)
- Petra Anne Levin
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
- Center for Science & Engineering of Living Systems (CSELS), McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Anuradha Janakiraman
- Department of Biology, The City College of New York, New York, New York, USA
- Programs in Biology and Biochemistry, The Graduate Center of the City University of New York, New York, New York, USA
| |
Collapse
|
22
|
Kohga H, Saito Y, Kanamaru M, Uchiyama J, Ohta H. The lack of the cell division protein FtsZ induced generation of giant cells under acidic stress in cyanobacterium Synechocystis sp. PCC6803. PHOTOSYNTHESIS RESEARCH 2021; 150:343-356. [PMID: 33146872 DOI: 10.1007/s11120-020-00792-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 10/23/2020] [Indexed: 06/11/2023]
Abstract
Bacteria exposed to environmental stresses often exhibit superior acclimation abilities to environmental change. Acid treatment causes an increase in the cell length of the cyanobacterium Synechocystis sp. PCC6803 under light conditions. We aimed to elucidate the relationship between acidic stress and cell enlargement. After being synchronized under dark conditions, the cells were cultivated at different pH (pH 8.0 or pH 6.0) levels under light conditions. Synechocystis 6803 cells exhibited only cell growth occurred (cell volume expansion) and slow proliferation under the acidic condition. In the recovery experiment of the enlarged cells, they proliferated normally at pH 8.0, and the cell lengths decreased to the normal cell size under light conditions. Inhibition of cell division might be caused by acidic stress. To understand the effect of acidic stress on cell division, we evaluated the expression of FtsZ via Western blotting. The FtsZ concentration in cells was lower at pH 6.0 than at pH 8.0 and was not sufficient for cell division in the photoautotrophic conditions. ClpXP is well known as a regulator of the Z-ring dynamics in E. coli. The transcriptional level of four clpXP genes was upregulated approximately threefold at pH 6.0 after 24 h compared with that in cells grown at pH 8.0. The lack of FtsZ may be caused by the upregulation of clpXP expression under acidic condition. Therefore, ClpXP may participate in the degradation of FtsZ and be involved in the regulation of cell division via FtsZ under acidic stress in Synechocystis 6803.
Collapse
Affiliation(s)
- Hidetaka Kohga
- Department of Mathematics and Science Education, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Yoshikazu Saito
- Department of Mathematics and Science Education, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Mirai Kanamaru
- Department of Mathematics and Science Education, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Junji Uchiyama
- Department of Mathematics and Science Education, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
- Department of Biology, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Hisataka Ohta
- Department of Mathematics and Science Education, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
- Department of Biology, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
| |
Collapse
|
23
|
Colin A, Micali G, Faure L, Cosentino Lagomarsino M, van Teeffelen S. Two different cell-cycle processes determine the timing of cell division in Escherichia coli. eLife 2021; 10:67495. [PMID: 34612203 PMCID: PMC8555983 DOI: 10.7554/elife.67495] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
Cells must control the cell cycle to ensure that key processes are brought to completion. In Escherichia coli, it is controversial whether cell division is tied to chromosome replication or to a replication-independent inter-division process. A recent model suggests instead that both processes may limit cell division with comparable odds in single cells. Here, we tested this possibility experimentally by monitoring single-cell division and replication over multiple generations at slow growth. We then perturbed cell width, causing an increase of the time between replication termination and division. As a consequence, replication became decreasingly limiting for cell division, while correlations between birth and division and between subsequent replication-initiation events were maintained. Our experiments support the hypothesis that both chromosome replication and a replication-independent inter-division process can limit cell division: the two processes have balanced contributions in non-perturbed cells, while our width perturbations increase the odds of the replication-independent process being limiting.
Collapse
Affiliation(s)
- Alexandra Colin
- Microbial Morphogenesis and Growth Laboratory, Institut Pasteur, Paris, France
| | - Gabriele Micali
- Department of Environmental Microbiology, Dübendorf, Switzerland.,Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Louis Faure
- Microbial Morphogenesis and Growth Laboratory, Institut Pasteur, Paris, France
| | - Marco Cosentino Lagomarsino
- IFOM, FIRC Institute of Molecular Oncology, Milan, Italy.,Physics Department, University of Milan, and INFN, Milan, Italy
| | - Sven van Teeffelen
- Microbial Morphogenesis and Growth Laboratory, Institut Pasteur, Paris, France.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Canada
| |
Collapse
|
24
|
The Ethanologenic Bacterium Zymomonas mobilis Divides Asymmetrically and Exhibits Heterogeneity in DNA Content. Appl Environ Microbiol 2021; 87:AEM.02441-20. [PMID: 33452021 DOI: 10.1128/aem.02441-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/23/2020] [Indexed: 02/04/2023] Open
Abstract
The alphaproteobacterium Zymomonas mobilis exhibits extreme ethanologenic physiology, making this species a promising biofuel producer. Numerous studies have investigated its biology relevant to industrial applications and mostly at the population level. However, the organization of single cells in this industrially important polyploid species has been largely uncharacterized. In the present study, we characterized basic cellular behavior of Z. mobilis strain Zm6 under anaerobic conditions at the single-cell level. We observed that growing Z. mobilis cells often divided at a nonmidcell position, which contributed to variant cell size at birth. However, the cell size variance was regulated by a modulation of cell cycle span, mediated by a correlation of bacterial tubulin homologue FtsZ ring accumulation with cell growth. The Z. mobilis culture also exhibited heterogeneous cellular DNA content among individual cells, which might have been caused by asynchronous replication of chromosome that was not coordinated with cell growth. Furthermore, slightly angled divisions might have resulted in temporary curvatures of attached Z. mobilis cells. Overall, the present study uncovers a novel bacterial cell organization in Z. mobilis IMPORTANCE With increasing environmental concerns about the use of fossil fuels, development of a sustainable biofuel production platform has been attracting significant public attention. Ethanologenic Z. mobilis species are endowed with an efficient ethanol fermentation capacity that surpasses, in several respects, that of baker's yeast (Saccharomyces cerevisiae), the most-used microorganism for ethanol production. For development of a Z. mobilis culture-based biorefinery, an investigation of its uncharacterized cell biology is important, because bacterial cellular organization and metabolism are closely associated with each other in a single cell compartment. In addition, the current work demonstrates that the polyploid bacterium Z. mobilis exhibits a distinctive mode of bacterial cell organization, likely reflecting its unique metabolism that does not prioritize incorporation of nutrients for cell growth. Thus, another significant result of this work is to advance our general understanding in the diversity of bacterial cell architecture.
Collapse
|
25
|
Qu T, Calabrese P, Singhavi P, Tower J. Incorporating antagonistic pleiotropy into models for molecular replicators. Biosystems 2020; 201:104333. [PMID: 33359635 DOI: 10.1016/j.biosystems.2020.104333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 11/15/2022]
Abstract
In modern cells, chromosomal genes composed of DNA encode multi-subunit protein/RNA complexes that catalyze the replication of the chromosome and cell. One prevailing theory for the origin of life posits an early stage involving self-replicating macromolecules called replicators, which can be considered genes capable of self-replication. One prevailing theory for the genetics of aging in humans and other organisms is antagonistic pleiotropy, which posits that a gene can be beneficial in one context, and detrimental in another context. We previously reported that the conceptual simplicity of molecular replicators facilitates the generation of two simple models involving antagonistic pleiotropy. Here a third model is proposed, and each of the three models is presented with improved definition of the time variable. Computer simulations were used to calculate the proliferation of a hypothetical two-subunit replicator (AB), when one of the two subunits (B) exhibits antagonistic pleiotropy, leading to an advantage for B to be unstable. In model 1, instability of B yields free A subunits, which in turn stimulate the activity of other AB replicators. In model 2, B is lost and sometimes replaced by a more active mutant form, B'. In model 3, B becomes damaged and loses activity, and its instability allows it to be replaced by a new B. For each model, conditions were identified where instability of B was detrimental, and where instability of B was beneficial. The results are consistent with the hypothesis that antagonistic pleiotropy can promote molecular instability and system complexity, and provide further support for a model linking aging and evolution.
Collapse
Affiliation(s)
- Tianjiao Qu
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Peter Calabrese
- Quantitative and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Pratik Singhavi
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
| |
Collapse
|
26
|
Serbanescu D, Ojkic N, Banerjee S. Nutrient-Dependent Trade-Offs between Ribosomes and Division Protein Synthesis Control Bacterial Cell Size and Growth. Cell Rep 2020; 32:108183. [DOI: 10.1016/j.celrep.2020.108183] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/24/2020] [Accepted: 09/01/2020] [Indexed: 01/06/2023] Open
|
27
|
Abstract
Most bacteria divide by corralling the tubulin-like FtsZ protein to mid-cell, where it assembles into a ring of treadmilling membrane-tethered oligomers. A study in this issue reveals new details about how FtsZ finds its way to the ring.
Collapse
|
28
|
Ho PY, Martins BMC, Amir A. A Mechanistic Model of the Regulation of Division Timing by the Circadian Clock in Cyanobacteria. Biophys J 2020; 118:2905-2913. [PMID: 32497517 DOI: 10.1016/j.bpj.2020.04.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 04/02/2020] [Accepted: 04/30/2020] [Indexed: 11/15/2022] Open
Abstract
The cyanobacterium Synechococcus elongatus possesses a circadian clock in the form of a group of proteins whose concentrations and phosphorylation states oscillate with daily periodicity under constant conditions. The circadian clock regulates the cell cycle such that the timing of the cell divisions is biased toward certain times during the circadian period, but the mechanism underlying this phenomenon remains unclear. Here, we propose a mechanism in which a protein limiting for division accumulates at a rate proportional to the cell volume growth and is modulated by the clock. This "modulated rate" model, in which the clock signal is integrated over time to affect division timing, differs fundamentally from the previously proposed "gating" concept, in which the clock is assumed to suppress divisions during a specific time window. We found that although both models can capture the single-cell statistics of division timing in S. elongatus, only the modulated rate model robustly places divisions away from darkness during changes in the environment. Moreover, within the framework of the modulated rate model, existing experiments on S. elongatus are consistent with the simple mechanism that division timing is regulated by the accumulation of a division limiting protein in a phase with genes whose activity peaks at dusk.
Collapse
Affiliation(s)
- Po-Yi Ho
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Bruno M C Martins
- Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Ariel Amir
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts.
| |
Collapse
|
29
|
Nieto C, Arias-Castro J, Sánchez C, Vargas-García C, Pedraza JM. Unification of cell division control strategies through continuous rate models. Phys Rev E 2020; 101:022401. [PMID: 32168656 DOI: 10.1103/physreve.101.022401] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/25/2019] [Indexed: 11/07/2022]
Abstract
Recent experiments support the adder model for E. coli division control. This model posits that bacteria grow, on average, a fixed size before division. It also predicts decorrelation between the noise in the added size and the size at birth. Here we develop a theory based on stochastic hybrid systems which could explain the main division strategies, including not only the adder strategy but the whole range from sizer to timer. We use experiments to explore the division control of E. coli growing with glycerol as carbon source. In this medium, the division strategy is sizerlike, which means that the added size decreases with the size at birth. We found, as our theory predicts, that in a sizerlike strategy the mean added size decreases with the size at birth while the noise in added size increases. We discuss possible molecular mechanisms underlying this strategy and propose a general model that encompasses the different division strategies.
Collapse
Affiliation(s)
- César Nieto
- Department of Physics, Universidad de los Andes, Bogotá, Colombia
| | - Juan Arias-Castro
- Department of Physics, Universidad de los Andes, Bogotá, Colombia.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Carlos Sánchez
- Department of Physics, Universidad de los Andes, Bogotá, Colombia.,Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - César Vargas-García
- Department of Mathematics and Engineering, Fundación Universitaria Konrad Lorenz, Bogotá, Colombia
| | | |
Collapse
|
30
|
Transient Membrane-Linked FtsZ Assemblies Precede Z-Ring Formation in Escherichia coli. Curr Biol 2020; 30:499-508.e6. [PMID: 31978334 DOI: 10.1016/j.cub.2019.12.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 11/06/2019] [Accepted: 12/06/2019] [Indexed: 11/22/2022]
Abstract
During the early stages of cytokinesis, FtsZ protofilaments form a ring-like structure, the Z-ring, in most bacterial species. This cytoskeletal scaffold recruits downstream proteins essential for septal cell wall synthesis. Despite progress in understanding the dynamic nature of the Z-ring and its role in coordinating septal cell wall synthesis, the early stages of protofilament formation and subsequent assembly into the Z-ring are still not understood. Here we investigate a sequence of assembly steps that lead to the formation of the Z-ring in Escherichia coli using high temporal and spatial resolution imaging. Our data show that formation of the Z-ring is preceded by transient membrane-linked FtsZ assemblies. These assemblies form after attachment of short cytosolic protofilaments, which we estimate to be less than 20 monomers long, to the membrane. The attachments occur at random locations along the length of the cell. The filaments treadmill and show periods of rapid growth and shrinkage. Their dynamic properties imply that protofilaments are bundled in these assemblies. Furthermore, we establish that the size of assemblies is sensitively controlled by the availability of FtsZ molecules and by the presence of ZapA proteins. The latter has been implicated in cross-linking the protofilaments. The likely function of these dynamic FtsZ assemblies is to sample the cell surface for the proper location for the Z-ring.
Collapse
|
31
|
Wang R, Kreutzfeldt K, Botella H, Vaubourgeix J, Schnappinger D, Ehrt S. Persistent Mycobacterium tuberculosis infection in mice requires PerM for successful cell division. eLife 2019; 8:49570. [PMID: 31751212 PMCID: PMC6872210 DOI: 10.7554/elife.49570] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 11/11/2019] [Indexed: 01/09/2023] Open
Abstract
The ability of Mycobacterium tuberculosis (Mtb) to persist in its host is central to the pathogenesis of tuberculosis, yet the underlying mechanisms remain incompletely defined. PerM, an integral membrane protein, is required for persistence of Mtb in mice. Here, we show that perM deletion caused a cell division defect specifically during the chronic phase of mouse infection, but did not affect Mtb’s cell replication during acute infection. We further demonstrate that PerM is required for cell division in chronically infected mice and in vitro under host-relevant stresses because it is part of the mycobacterial divisome and stabilizes the essential divisome protein FtsB. These data highlight the importance of sustained cell division for Mtb persistence, define condition-specific requirements for cell division and reveal that survival of Mtb during chronic infection depends on a persistence divisome.
Collapse
Affiliation(s)
- Ruojun Wang
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States.,Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, United States
| | - Kaj Kreutzfeldt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Helene Botella
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Julien Vaubourgeix
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States.,Immunology and Microbial Pathogenesis Graduate Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, United States
| |
Collapse
|
32
|
Witz G, van Nimwegen E, Julou T. Initiation of chromosome replication controls both division and replication cycles in E. coli through a double-adder mechanism. eLife 2019; 8:48063. [PMID: 31710292 PMCID: PMC6890467 DOI: 10.7554/elife.48063] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/07/2019] [Indexed: 11/13/2022] Open
Abstract
Living cells proliferate by completing and coordinating two cycles, a division cycle controlling cell size and a DNA replication cycle controlling the number of chromosomal copies. It remains unclear how bacteria such as Escherichia coli tightly coordinate those two cycles across a wide range of growth conditions. Here, we used time-lapse microscopy in combination with microfluidics to measure growth, division and replication in single E. coli cells in both slow and fast growth conditions. To compare different phenomenological cell cycle models, we introduce a statistical framework assessing their ability to capture the correlation structure observed in the data. In combination with stochastic simulations, our data indicate that the cell cycle is driven from one initiation event to the next rather than from birth to division and is controlled by two adder mechanisms: the added volume since the last initiation event determines the timing of both the next division and replication initiation events.
Collapse
Affiliation(s)
- Guillaume Witz
- Biozentrum, University of Basel, Basel, Switzerland.,Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Erik van Nimwegen
- Biozentrum, University of Basel, Basel, Switzerland.,Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Thomas Julou
- Biozentrum, University of Basel, Basel, Switzerland.,Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| |
Collapse
|
33
|
Zaritsky A, Vollmer W, Männik J, Liu C. Does the Nucleoid Determine Cell Dimensions in Escherichia coli? Front Microbiol 2019; 10:1717. [PMID: 31447799 PMCID: PMC6691162 DOI: 10.3389/fmicb.2019.01717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/11/2019] [Indexed: 11/13/2022] Open
Abstract
Bacillary, Gram-negative bacteria grow by elongation with no discernible change in width, but during faster growth in richer media the cells are also wider. The mechanism regulating the change in cell width W during transitions from slow to fast growth is a fundamental, unanswered question in molecular biology. The value of W that changes in the divisome and during the division process only, is related to the nucleoid complexity, determined by the rates of growth and of chromosome replication; the former is manipulated by nutritional conditions and the latter-by thymine limitation of thyA mutants. Such spatio-temporal regulation is supported by existence of a minimal possible distance between successive replisomes, so-called eclipse that limits the number of replisomes to a maximum. Breaching this limit by slowing replication in fast growing cells results in maximal nucleoid complexity that is associated with maximum cell width, supporting the notion of Nucleoid-to-Divisome signal transmission. Physical signal(s) may be delivered from the nucleoid to assemble the divisome and to fix the value of W in the nascent cell pole.
Collapse
Affiliation(s)
- Arieh Zaritsky
- Faculty of Natural Sciences, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jaan Männik
- Department of Physics & Astronomy, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Chenli Liu
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| |
Collapse
|
34
|
Si F, Le Treut G, Sauls JT, Vadia S, Levin PA, Jun S. Mechanistic Origin of Cell-Size Control and Homeostasis in Bacteria. Curr Biol 2019; 29:1760-1770.e7. [PMID: 31104932 DOI: 10.1016/j.cub.2019.04.062] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/18/2019] [Accepted: 04/24/2019] [Indexed: 02/06/2023]
Abstract
Evolutionarily divergent bacteria share a common phenomenological strategy for cell-size homeostasis under steady-state conditions. In the presence of inherent physiological stochasticity, cells following this "adder" principle gradually return to their steady-state size by adding a constant volume between birth and division, regardless of their size at birth. However, the mechanism of the adder has been unknown despite intense efforts. In this work, we show that the adder is a direct consequence of two general processes in biology: (1) threshold-accumulation of initiators and precursors required for cell division to a respective fixed number-and (2) balanced biosynthesis-maintenance of their production proportional to volume growth. This mechanism is naturally robust to static growth inhibition but also allows us to "reprogram" cell-size homeostasis in a quantitatively predictive manner in both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. By generating dynamic oscillations in the concentration of the division protein FtsZ, we were able to oscillate cell size at division and systematically break the adder. In contrast, periodic induction of replication initiator protein DnaA caused oscillations in cell size at initiation but did not alter division size or the adder. Finally, we were able to restore the adder phenotype in slow-growing E. coli, the only known steady-state growth condition wherein E. coli significantly deviates from the adder, by repressing active degradation of division proteins. Together, these results show that cell division and replication initiation are independently controlled at the gene-expression level and that division processes exclusively drive cell-size homeostasis in bacteria. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Fangwei Si
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Guillaume Le Treut
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - John T Sauls
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephen Vadia
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Petra Anne Levin
- Department of Biology, Washington University in St. Louis, Saint Louis, MO 63130, USA
| | - Suckjoon Jun
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, USA; Section of Molecular Biology, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
35
|
Brzozowski RS, Huber M, Burroughs AM, Graham G, Walker M, Alva SS, Aravind L, Eswara PJ. Deciphering the Role of a SLOG Superfamily Protein YpsA in Gram-Positive Bacteria. Front Microbiol 2019; 10:623. [PMID: 31024470 PMCID: PMC6459960 DOI: 10.3389/fmicb.2019.00623] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 03/12/2019] [Indexed: 12/27/2022] Open
Abstract
Bacteria adapt to different environments by regulating cell division and several conditions that modulate cell division have been documented. Understanding how bacteria transduce environmental signals to control cell division is critical in understanding the global network of cell division regulation. In this article we describe a role for Bacillus subtilis YpsA, an uncharacterized protein of the SLOG superfamily of nucleotide and ligand-binding proteins, in cell division. We observed that YpsA provides protection against oxidative stress as cells lacking ypsA show increased susceptibility to hydrogen peroxide treatment. We found that the increased expression of ypsA leads to filamentation and disruption of the assembly of FtsZ, the tubulin-like essential protein that marks the sites of cell division in B. subtilis. We also showed that YpsA-mediated filamentation is linked to the growth rate. Using site-directed mutagenesis, we targeted several conserved residues and generated YpsA variants that are no longer able to inhibit cell division. Finally, we show that the role of YpsA is possibly conserved in Firmicutes, as overproduction of YpsA in Staphylococcus aureus also impairs cell division.
Collapse
Affiliation(s)
- Robert S Brzozowski
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - Mirella Huber
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States
| | - Gianni Graham
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - Merryck Walker
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - Sameeksha S Alva
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States
| | - Prahathees J Eswara
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| |
Collapse
|
36
|
Sekar K, Rusconi R, Sauls JT, Fuhrer T, Noor E, Nguyen J, Fernandez VI, Buffing MF, Berney M, Jun S, Stocker R, Sauer U. Synthesis and degradation of FtsZ quantitatively predict the first cell division in starved bacteria. Mol Syst Biol 2018; 14:e8623. [PMID: 30397005 PMCID: PMC6217170 DOI: 10.15252/msb.20188623] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/01/2018] [Accepted: 10/11/2018] [Indexed: 12/21/2022] Open
Abstract
In natural environments, microbes are typically non-dividing and gauge when nutrients permit division. Current models are phenomenological and specific to nutrient-rich, exponentially growing cells, thus cannot predict the first division under limiting nutrient availability. To assess this regime, we supplied starving Escherichia coli with glucose pulses at increasing frequencies. Real-time metabolomics and microfluidic single-cell microscopy revealed unexpected, rapid protein, and nucleic acid synthesis already from minuscule glucose pulses in non-dividing cells. Additionally, the lag time to first division shortened as pulsing frequency increased. We pinpointed division timing and dependence on nutrient frequency to the changing abundance of the division protein FtsZ. A dynamic, mechanistic model quantitatively relates lag time to FtsZ synthesis from nutrient pulses and FtsZ protease-dependent degradation. Lag time changed in model-congruent manners, when we experimentally modulated the synthesis or degradation of FtsZ. Thus, limiting abundance of FtsZ can quantitatively predict timing of the first cell division.
Collapse
Affiliation(s)
- Karthik Sekar
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Roberto Rusconi
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
| | - John T Sauls
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Tobias Fuhrer
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Elad Noor
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Jen Nguyen
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vicente I Fernandez
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Marieke F Buffing
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- Life Science Zurich PhD Program on Systems Biology, Zurich, Switzerland
| | - Michael Berney
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Suckjoon Jun
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
- Section of Molecular Biology, Division of Biological Science, University of California at San Diego, La Jolla, CA, USA
| | - Roman Stocker
- Department of Civil, Environmental and Geomatic Engineering, Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Uwe Sauer
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| |
Collapse
|