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Craft DL, Korza G, Zhang Y, Frindert J, Jäschke A, Caimano MJ, Setlow P. Analysis of 5'-NAD capping of mRNAs in dormant spores of Bacillus subtilis. FEMS Microbiol Lett 2021; 367:5895323. [PMID: 32821945 DOI: 10.1093/femsle/fnaa143] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022] Open
Abstract
Spores of Gram-positive bacteria contain 10s-1000s of different mRNAs. However, Bacillus subtilis spores contain only ∼ 50 mRNAs at > 1 molecule/spore, almost all transcribed only in the developing spore and encoding spore proteins. However, some spore mRNAs could be stabilized to ensure they are intact in dormant spores, perhaps to direct synthesis of proteins essential for spores' conversion to a growing cell in germinated spore outgrowth. Recent work shows that some growing B. subtilis cell mRNAs contain a 5'-NAD cap. Since this cap may stabilize mRNA in vivo, its presence on spore mRNAs would suggest that maintaining some intact spore mRNAs is important, perhaps because they have a translational role in outgrowth. However, significant levels of only a few abundant spore mRNAs had a 5'-NAD cap, and these were not the most stable spore mRNAs and had likely been fragmented. Even higher levels of 5'-NAD-capping were found on a few low abundance spore mRNAs, but these mRNAs were present in only small percentages of spores, and had again been fragmented. The new data are thus consistent with spore mRNAs serving only as a reservoir of ribonucleotides in outgrowth.
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Affiliation(s)
- D Levi Craft
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | - George Korza
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
| | - Yaqing Zhang
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Jens Frindert
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Andres Jäschke
- Institute of Pharmacy and Molecular Biotechnology, Im Neuenheimer Feld, Heidelberg University, 69120, Heidelberg, Germany
| | - Melissa J Caimano
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA.,Department of Medicine, UConn Health, Farmington, CT 06030-3305, USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-3305, USA
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2
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Levels and Characteristics of mRNAs in Spores of Firmicute Species. J Bacteriol 2021; 203:e0001721. [PMID: 33972352 DOI: 10.1128/jb.00017-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spores of firmicute species contain 100s of mRNAs, whose major function in Bacillus subtilis is to provide ribonucleotides for new RNA synthesis when spores germinate. To determine if this is a general phenomenon, RNA was isolated from spores of multiple firmicute species and relative mRNA levels determined by transcriptome sequencing (RNA-seq). Determination of RNA levels in single spores allowed calculation of RNA nucleotides/spore, and assuming mRNA is 3% of spore RNA indicated that only ∼6% of spore mRNAs were present at >1/spore. Bacillus subtilis, Bacillus atrophaeus, and Clostridioides difficile spores had 49, 42, and 51 mRNAs at >1/spore, and numbers of mRNAs at ≥1/spore were ∼10 to 50% higher in Geobacillus stearothermophilus and Bacillus thuringiensis Al Hakam spores and ∼4-fold higher in Bacillus megaterium spores. In all species, some to many abundant spore mRNAs (i) were transcribed by RNA polymerase with forespore-specific σ factors, (ii) encoded proteins that were homologs of those encoded by abundant B. subtilis spore mRNAs and are proteins in dormant spores, and (iii) were likely transcribed in the mother cell compartment of the sporulating cell. Analysis of the coverage of RNA-seq reads on mRNAs from all species suggested that abundant spore mRNAs were fragmented, as was confirmed by reverse transcriptase quantitative PCR (RT-qPCR) analysis of abundant B. subtilis and C. difficile spore mRNAs. These data add to evidence indicating that the function of at least the great majority of mRNAs in all firmicute spores is to be degraded to generate ribonucleotides for new RNA synthesis when spores germinate. IMPORTANCE Only ∼6% of mRNAs in spores of six firmicute species are at ≥1 molecule/spore, many abundant spore mRNAs encode proteins similar to B. subtilis spore proteins, and some abundant B. subtilis and C. difficile spore mRNAs were fragmented. Most of the abundant B. subtilis and other Bacillales spore mRNAs are transcribed under the control of the forespore-specific RNA polymerase σ factors, F or G, and these results may stimulate transcription analyses in developing spores of species other than B. subtilis. These findings, plus the absence of key nucleotide biosynthetic enzymes in spores, suggest that firmicute spores' abundant mRNAs are not translated when spores germinate but instead are degraded to generate ribonucleotides for new RNA synthesis by the germinated spore.
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3
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DeMarco AM, Korza G, Granados MR, Mok WWK, Setlow P. Dodecylamine rapidly kills of spores of multiple Firmicute species: properties of the killed spores and the mechanism of the killing. J Appl Microbiol 2021; 131:2612-2625. [PMID: 33998749 DOI: 10.1111/jam.15137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/28/2021] [Accepted: 05/09/2021] [Indexed: 01/07/2023]
Abstract
AIMS Previous work showed that Bacillus subtilis dormant spore killing and germination by dodecylamine take place by different mechanisms. This new work aimed to optimize killing of B. subtilis and other Firmicutes spores and to determine the mechanism of the killing. METHODS AND RESULTS Spores of seven Firmicute species were killed rapidly by dodecylamine under optimal conditions and more slowly by decylamine or tetradecylamine. The killed spores were not recovered by additions to recovery media, and some of the killed spores subsequently germinated, all indicating that dodecylamine-killed spores truly are dead. Spores of two species treated with dodecylamine were more sensitive to killing by a subsequent heat treatment, and spore killing of at least one species was faster with chemically decoated spores. The cores of dodecylamine-killed spores were stained by the nucleic acid stain propidium iodide, and dodecylamine-killed wild-type and germination-deficient spores released their stores of phosphate-containing small molecules. CONCLUSIONS This work indicates that dodecylamine is likely a universal sporicide for Firmicute species, and it kills spores by damaging their inner membrane, with attendant loss of this membrane as a permeability barrier. SIGNIFICANCE AND IMPACT OF THE STUDY There is a significant need for agents that can effectively kill spores of a number of Firmicute species, especially in wide area decontamination. Dodecylamine appears to be a universal sporicide with a novel mechanism of action, and this or some comparable molecule could be useful in wide area spore decontamination.
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Affiliation(s)
- A M DeMarco
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - G Korza
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - M R Granados
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - W W K Mok
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| | - P Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
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Implementation of ATP and Microbial Indicator Testing for Hygiene Monitoring in a Tofu Production Facility Improves Product Quality and Hygienic Conditions of Food Contact Surfaces: A Case Study. Appl Environ Microbiol 2021; 87:AEM.02278-20. [PMID: 33361369 PMCID: PMC8090886 DOI: 10.1128/aem.02278-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Rapid ATP testing and microbiological enumeration are two common methods to monitor the effectiveness of cleaning and sanitation in the food industry. In this study, ATP testing and microbiological enumeration were implemented at a tofu production facility with the goal of improving cleaning practices and overall plant hygiene. Results from ATP monitoring were used to target areas of the production environment needing additional cleaning; ATP results were verified by microbiological enumeration of aerobic microorganisms, lactic acid bacteria, and yeasts and molds. Products from the production line were enumerated for the same microorganisms to determine if there was an impact on product quality. After the implementation of ATP monitoring and targeted cleaning, there was a statistically lower proportion of swabs that failed to meet established sanitary requirements for ATP, aerobic microorganisms, and lactic acid bacteria (p < 0.05), but not for yeasts and molds. ATP swabs and microbiological enumeration agreed on site hygiene 75.1% (72.3-77.7%, 95% CI) of the time. Product data indicated that unpasteurized finished products contained a statistically lower microbial load of the three groups of organisms following implementation of the practices (p < 0.05).ImportanceCleaning and sanitation are critical to maintaining safe and high-quality food production. Monitoring these activities is important to ensure proper execution of procedure and to assure compliance with regulatory guidelines. The results from monitoring activities can direct targeted cleaning of areas with higher risk of contamination from foodstuffs and microorganisms. The results of this study show that ATP monitoring and microbiological enumeration are useful tools to verify and improve the efficacy of cleaning and sanitation practices, which can have a positive impact on both plant hygiene and product quality. However, testing regimes and critical parameters will vary based on the product and facility.
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Yeom J, Groisman EA. Reduced ATP-dependent proteolysis of functional proteins during nutrient limitation speeds the return of microbes to a growth state. Sci Signal 2021; 14:14/667/eabc4235. [PMID: 33500334 DOI: 10.1126/scisignal.abc4235] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
When cells run out of nutrients, the growth rate greatly decreases. Here, we report that microorganisms, such as the bacterium Salmonella enterica serovar Typhimurium, speed up the return to a rapid growth state by preventing the proteolysis of functional proteins by ATP-dependent proteases while in the slow-growth state or stationary phase. This reduction in functional protein degradation resulted from a decrease in the intracellular concentration of ATP that was nonetheless sufficient to allow the continued degradation of nonfunctional proteins by the same proteases. Protein preservation occurred under limiting magnesium, carbon, or nitrogen conditions, indicating that this response was not specific to low availability of a particular nutrient. Nevertheless, the return to rapid growth required proteins that mediate responses to the specific nutrient limitation conditions, because the transcriptional regulator PhoP was necessary for rapid recovery only after magnesium starvation. Reductions in intracellular ATP and in ATP-dependent proteolysis also enabled the yeast Saccharomyces cerevisiae to recover faster from stationary phase. Our findings suggest that protein preservation during a slow-growth state is a conserved microbial strategy that facilitates the return to a growth state once nutrients become available.
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Affiliation(s)
- Jinki Yeom
- Department of Microbial Pathogenesis, Yale School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.,Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore 169857, Singapore.,Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, Korea.,Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Korea
| | - Eduardo A Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA. .,Yale Microbial Sciences Institute, P.O. Box 27389, West Haven, CT 06516, USA
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Setlow P, Christie G. Bacterial Spore mRNA - What's Up With That? Front Microbiol 2020; 11:596092. [PMID: 33193276 PMCID: PMC7649253 DOI: 10.3389/fmicb.2020.596092] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/28/2020] [Indexed: 01/19/2023] Open
Abstract
Bacteria belonging to the orders Bacillales and Clostridiales form spores in response to nutrient starvation. From a simplified morphological perspective, the spore can be considered as comprising a central protoplast or core, that is, enveloped sequentially by an inner membrane (IM), a peptidoglycan cortex, an outer membrane, and a proteinaceous coat. All of these structures are characterized by unique morphological and/or structural features, which collectively confer metabolic dormancy and properties of environmental resistance to the quiescent spore. These properties are maintained until the spore is stimulated to germinate, outgrow and form a new vegetative cell. Spore germination comprises a series of partially overlapping biochemical and biophysical events - efflux of ions from the core, rehydration and IM reorganization, disassembly of cortex and coat - all of which appear to take place in the absence of de novo ATP and protein synthesis. If the latter points are correct, why then do spores of all species examined to date contain a diverse range of mRNA molecules deposited within the spore core? Are some of these molecules "functional," serving as translationally active units that are required for efficient spore germination and outgrowth, or are they just remnants from sporulation whose sole purpose is to provide a reservoir of ribonucleotides for the newly outgrowing cell? What is the fate of these molecules during spore senescence, and indeed, are conditions within the spore core likely to provide any opportunity for changes in the transcriptional profile of the spore during dormancy? This review encompasses a historical perspective of spore ribonucleotide biology, from the earliest biochemical led analyses - some of which in hindsight have proved to be remarkably prescient - through the transcriptomic era at the turn of this century, to the latest next generation sequencing derived insights. We provide an overview of the key literature to facilitate reasoned responses to the aforementioned questions, and many others, prior to concluding by identifying the major outstanding issues in this crucial area of spore biology.
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Affiliation(s)
- Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT, United States
| | - Graham Christie
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
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7
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Xing Y, Harper WF. Bacillus spore awakening: recent discoveries and technological developments. Curr Opin Biotechnol 2020; 64:110-115. [DOI: 10.1016/j.copbio.2019.12.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 12/25/2022]
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Christie G, Setlow P. Bacillus spore germination: Knowns, unknowns and what we need to learn. Cell Signal 2020; 74:109729. [PMID: 32721540 DOI: 10.1016/j.cellsig.2020.109729] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/18/2020] [Accepted: 07/21/2020] [Indexed: 01/06/2023]
Abstract
How might a microbial cell that is entirely metabolically dormant - and which has the ability to remain so for extended periods of time - irreversibly commit itself to resuming vegetative growth within seconds of being exposed to certain amino acids or sugars? That this process takes place in the absence of any detectable ATP or de novo protein synthesis, and relies upon a pre-formed apparatus that is immobilised, respectively, in a semi-crystalline membrane or multi-layered proteinaceous coat, only exacerbates the challenge facing spores of Bacillales species when stimulated to germinate. Whereas the process by which spores are formed in response to nutrient starvation - sporulation - involves the orchestrated interplay between hundreds of distinct proteins, the process by which spores return to life - germination - is a much simpler affair, requiring a handful of receptor and channel proteins complemented with specialized peptidoglycan lysins. Despite this relative simplicity, and research effort spanning many decades, comprehensive understanding of key molecular and biochemical details and, in particular signal transduction mechanisms associated with spore germination, has remained elusive. In this review we provide an up to date overview of the field while identifying what we consider to be the key gaps in knowledge associated with germination of Bacillales spores, suggesting also technical approaches that may provide fresh insight to this unique biological process.
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Affiliation(s)
- Graham Christie
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 OAS, United Kingdom.
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, CT 06030-3305, USA.
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9
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Properties of Aged Spores of Bacillus subtilis. J Bacteriol 2019; 201:JB.00231-19. [PMID: 31061168 DOI: 10.1128/jb.00231-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 04/28/2019] [Indexed: 12/25/2022] Open
Abstract
Bacillus spores incubated on plates for 2 to 98 days at 37°C had identical Ca-dipicolinic acid contents, exhibited identical viability on rich- or poor-medium plates, germinated identically in liquid with all germinants tested, identically returned to vegetative growth in rich or minimal medium, and exhibited essentially identical resistance to dry heat and similar resistance to UV radiation. However, the oldest spores had a lower core water content and significantly higher wet heat and NaOCl resistance. In addition, 47- and 98-day spores had lost >98% of intact 16S and 23S rRNA and 97 to 99% of almost all mRNAs, although minimal amounts of mononucleotides were generated in 91 days. Levels of 3-phosphoglyceric acid (3PGA) also fell 30 to 60% in the oldest spores, but how the 3PGA was lost is not clear. These results indicate that (i) translation of dormant spore mRNA is not essential for completion of spore germination, nor is protein synthesis from any mRNA; (ii) in sporulation for up to 91 days at 37°C, the RNA broken down generates minimal levels of mononucleotides; and (iii) the lengths of time that spores are incubated in sporulation medium should be considered when determining conditions for spore inactivation by wet heat, in particular, in using spores to test for the efficacy of sterilization regimens.IMPORTANCE We show that spores incubated at 37°C on sporulation plates for up to 98 days have lost almost all mRNAs and rRNAs, yet the aged spores germinated and outgrew as well as 2-day spores, and all these spores had identical viability. Thus, it is unlikely that spore mRNA, rRNA, or protein synthesis is important in spore germination. Spores incubated for 47 to 98 days also had much higher wet heat resistance than 2-day spores, suggesting that spore "age" should be considered in generating spores for tests of sterilization assurance. These data are the first to show complete survival of hydrated spores for ∼100 days, complementing published data showing dry-spore survival for years.
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10
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Abstract
Bacterial spores can remain dormant for years but possess the remarkable ability to germinate, within minutes, once nutrients become available. However, it still remains elusive how such instant awakening of cellular machineries is achieved. Utilizing Bacillus subtilis as a model, we show that YwlE arginine (Arg) phosphatase is crucial for spore germination. Accordingly, the absence of the Arg kinase McsB accelerated the process. Arg phosphoproteome of dormant spores uncovered a unique set of Arg-phosphorylated proteins involved in key biological functions, including translation and transcription. Consequently, we demonstrate that during germination, YwlE dephosphorylates an Arg site on the ribosome-associated chaperone Tig, enabling its association with the ribosome to reestablish translation. Moreover, we show that Arg dephosphorylation of the housekeeping σ factor A (SigA), mediated by YwlE, facilitates germination by activating the transcriptional machinery. Subsequently, we reveal that transcription is reinitiated at the onset of germination and its recommencement precedes that of translation. Thus, Arg dephosphorylation elicits the most critical stages of spore molecular resumption, placing this unusual post-translational modification as a major regulator of a developmental process in bacteria.
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11
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12
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Analysis of the mRNAs in Spores of Bacillus subtilis. J Bacteriol 2019; 201:JB.00007-19. [PMID: 30782632 DOI: 10.1128/jb.00007-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 02/08/2019] [Indexed: 12/12/2022] Open
Abstract
Large-scale shotgun sequencing (RNA-seq) analysis of mRNAs in dormant Bacillus subtilis spores prepared on plates or in liquid generally found the same ∼46 abundant mRNA species, with >250 mRNAs detected at much lower abundances. Knowledge of the amount of phosphate in a single B. subtilis spore allowed calculation of the amount of mRNA in an individual spore as ∼106 nucleotides (nt). Given the levels of abundant spore mRNAs compared to those of other mRNAs, it was calculated that the great majority of low-abundance mRNAs are present in only small fractions of spores in populations. Almost all of the most abundant spore mRNAs are encoded by genes expressed late in sporulation in the developing spore under the control of the forespore-specific RNA polymerase sigma factor, σG, and most of the encoded proteins are in spores. Levels of the most abundant spore mRNAs were also relatively stable for a week at 4°C after spore harvest. RNA-seq analysis of mRNAs in highly purified and less-well-purified spores made in liquid, as well as from spores that were chemically decoated to remove possible contaminating mRNA, indicated that low-abundance mRNAs in spores were not contaminants in purified spore preparations, and several sources of low-abundance mRNAs in spores are suggested. The function of at least the great majority of spore mRNAs seems most likely to be the generation of ribonucleotides for new RNA synthesis by their degradation early in spore revival.IMPORTANCE Previous work indicates that dormant Bacillus subtilis spores have many hundreds of mRNAs, some of which are suggested to play roles in spores' "return to life" or revival. The present work finds only ∼46 mRNAs at ≥1 molecule spore, with others in only fractions of spores in populations, often very small fractions. Less-abundant spore mRNAs are not contaminants in spore preparations, but how spores accumulate them is not clear. Almost all abundant spore mRNAs are synthesized in the developing spore late in its development, most encode proteins in spores, and abundant mRNAs in spores are relatively stable at 4°C. These findings will have a major impact on thinking about the roles that spore mRNAs may play in spore revival.
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Virmani R, Sajid A, Singhal A, Gaur M, Joshi J, Bothra A, Garg R, Misra R, Singh VP, Molle V, Goel AK, Singh A, Kalia VC, Lee JK, Hasija Y, Arora G, Singh Y. The Ser/Thr protein kinase PrkC imprints phenotypic memory in Bacillus anthracis spores by phosphorylating the glycolytic enzyme enolase. J Biol Chem 2019; 294:8930-8941. [PMID: 30952697 DOI: 10.1074/jbc.ra118.005424] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/18/2019] [Indexed: 01/05/2023] Open
Abstract
Bacillus anthracis is the causative agent of anthrax in humans, bovine, and other animals. B. anthracis pathogenesis requires differentiation of dormant spores into vegetative cells. The spores inherit cellular components as phenotypic memory from the parent cell, and this memory plays a critical role in facilitating the spores' revival. Because metabolism initiates at the beginning of spore germination, here we metabolically reprogrammed B. anthracis cells to understand the role of glycolytic enzymes in this process. We show that increased expression of enolase (Eno) in the sporulating mother cell decreases germination efficiency. Eno is phosphorylated by the conserved Ser/Thr protein kinase PrkC which decreases the catalytic activity of Eno. We found that phosphorylation also regulates Eno expression and localization, thereby controlling the overall spore germination process. Using MS analysis, we identified the sites of phosphorylation in Eno, and substitution(s) of selected phosphorylation sites helped establish the functional correlation between phosphorylation and Eno activity. We propose that PrkC-mediated regulation of Eno may help sporulating B. anthracis cells in adapting to nutrient deprivation. In summary, to the best of our knowledge, our study provides the first evidence that in sporulating B. anthracis, PrkC imprints phenotypic memory that facilitates the germination process.
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Affiliation(s)
- Richa Virmani
- From the Department of Zoology, University of Delhi, Delhi 110007, India.,Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India.,Delhi Technological University, Delhi 110042, India
| | - Andaleeb Sajid
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Anshika Singhal
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Mohita Gaur
- From the Department of Zoology, University of Delhi, Delhi 110007, India
| | - Jayadev Joshi
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Ankur Bothra
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Richa Garg
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Richa Misra
- From the Department of Zoology, University of Delhi, Delhi 110007, India.,Sri Venkateswara College, University of Delhi, Delhi 110021, India
| | - Vijay Pal Singh
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Virginie Molle
- Dynamique des Interactions Membranaires Normales et Pathologiques (DIMNP), CNRS, University of Montpellier, Montpellier 34000, France
| | - Ajay K Goel
- Defence Research and Development Establishment, Gwalior 474002, India
| | - Archana Singh
- Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
| | - Vipin C Kalia
- Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul 05029, Republic of Korea, and
| | - Jung-Kul Lee
- Department of Chemical Engineering, Konkuk University, 1 Hwayang-Dong, Gwangjin-Gu, Seoul 05029, Republic of Korea, and
| | - Yasha Hasija
- Delhi Technological University, Delhi 110042, India
| | - Gunjan Arora
- From the Department of Zoology, University of Delhi, Delhi 110007, India, .,Laboratory of Immunogenetics, NIAID, National Institutes of Health, Rockville, Maryland 20851
| | - Yogendra Singh
- From the Department of Zoology, University of Delhi, Delhi 110007, India, .,Council of Scientific and Industrial Research (CSIR)-Institute of Genomics and Integrative Biology, Delhi 110007, India
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14
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Bertrand C, Thibessard A, Bruand C, Lecointe F, Leblond P. Bacterial NHEJ: a never ending story. Mol Microbiol 2019; 111:1139-1151. [PMID: 30746801 DOI: 10.1111/mmi.14218] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2019] [Indexed: 12/30/2022]
Abstract
Double-strand breaks (DSBs) are the most detrimental DNA damage encountered by bacterial cells. DBSs can be repaired by homologous recombination thanks to the availability of an intact DNA template or by Non-Homologous End Joining (NHEJ) when no intact template is available. Bacterial NHEJ is performed by sets of proteins of growing complexity from Bacillus subtilis and Mycobacterium tuberculosis to Streptomyces and Sinorhizobium meliloti. Here, we discuss the contribution of these models to the understanding of the bacterial NHEJ repair mechanism as well as the involvement of NHEJ partners in other DNA repair pathways. The importance of NHEJ and of its complexity is discussed in the perspective of regulation through the biological cycle of the bacteria and in response to environmental stimuli. Finally, we consider the role of NHEJ in genome evolution, notably in horizontal gene transfer.
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Affiliation(s)
- Claire Bertrand
- Université de Lorraine, INRA, DynAMic, Nancy, F-54000, France
| | | | - Claude Bruand
- Laboratoire des Interactions Plantes-Microorganismes, Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - François Lecointe
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, 78350, France
| | - Pierre Leblond
- Université de Lorraine, INRA, DynAMic, Nancy, F-54000, France
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15
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Soni A, Oey I, Silcock P, Permina E, Bremer PJ. Differential gene expression for investigation of the effect of germinants and heat activation to induce germination in Bacillus cereus spores. Food Res Int 2018; 119:462-468. [PMID: 30884678 DOI: 10.1016/j.foodres.2018.12.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 12/10/2018] [Accepted: 12/22/2018] [Indexed: 11/15/2022]
Abstract
Differential gene expression was used to explore the mechanisms underpinning the differences in the impact of heat activation (70 °C for 30 min) on the germination of Bacillus cereus spores in the presence and absence of a germinant (L-alanine). The number of germinated cells, after heat activation plus L-alanine (3.5 ± 0.02 log CFU/ml) in the spore only initial population was found to be higher than that in only heat activated spores (2.01 ± 0.02 log CFU/ml). The concentration of DPA released by heat activated spores in the presence of L-alanine was 68.3 ± 0.1 and 112.1 ± 0.02 μg/ml after 30 and 60 min, compared to 96.5 and 166.2 ± 0.01 μg/ml after 30 and 90 min, respectively released by spores subjected only to heat activation. Gene (BC0784) encoding for the spore germination protein, gerA operon was up-regulated with a log2-transformed fold change value of 1.2 due to heat activation in the presence of L-alanine. The GerA operon located in the inner membrane is known to be involved in the uptake of L-alanine by B. cereus and has been reported to be involved in L-alanine mediated germination. In addition the up-regulation of genes involved in the uptake of L-alanine is proposed to provide the answer to the synergistic effect of heat and L-alanine in inducing germination in B. cereus spores. In short, heat activation increases the ability of L-alanine to penetrate into the spore's inner membrane, where it can be recognized by the receptors for initiation of the germination pathway. In the current study, the majority of the ribosomal proteins were down-regulated (when spores were heat treated in presence of germinants) this process also appeared to slow down protein synthesis by restricting the protein translation machinery. Differential gene expression revealed the genes responsible for the pathways related to transport and recognition of L-alanine into the spore that could have led to the accelerated germination process along with partial shutting down of protein synthesis pathway and ABC transporters. Knowledge of gene regulation in spores during heat activation will help in the development of approaches to prevent spore germination, which could provide an additional safeguard against bacterial growth and toxin production in improperly cooled heat treated foods.
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Affiliation(s)
- Aswathi Soni
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Indrawati Oey
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Riddet Institute, Palmerston North, New Zealand
| | - Patrick Silcock
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Elizabeth Permina
- Otago Genomics & Bioinformatics Facility, University of Otago, New Zealand
| | - Phil J Bremer
- Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand; New Zealand Food Safety Science Research Centre, New Zealand.
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16
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Omardien S, Drijfhout JW, Zaat SA, Brul S. Cationic Amphipathic Antimicrobial Peptides Perturb the Inner Membrane of Germinated Spores Thus Inhibiting Their Outgrowth. Front Microbiol 2018; 9:2277. [PMID: 30319583 PMCID: PMC6168669 DOI: 10.3389/fmicb.2018.02277] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/06/2018] [Indexed: 11/13/2022] Open
Abstract
The mode of action of four cationic amphipathic antimicrobial peptides (AMPs) was evaluated against the non-pathogenic, Gram-positive, spore-forming bacterium, Bacillus subtilis. The AMPs were TC19, TC84, BP2, and the lantibiotic Nisin A. TC19 and TC84 were derived from the human thrombocidin-1. Bactericidal peptide 2 (BP2) was derived from the human bactericidal permeability increasing protein (BPI). We employed structured illumination microscopy (SIM), fluorescence microscopy, Alexa 488-labeled TC84, B. subtilis mutants producing proteins fused to the green fluorescent protein (GFP) and single-cell live imaging to determine the effects of the peptides against spores. TC19, TC84, BP2, and Nisin A showed to be bactericidal against germinated spores by perturbing the inner membrane, thus preventing outgrowth to vegetative cells. Single cell live imaging showed that the AMPs do not affect the germination process, but the burst time and subsequent generation time of vegetative cells. Alexa 488-labeled TC84 suggested that the TC84 might be binding to the dormant spore-coat. Therefore, dormant spores were also pre-coated with the AMPs and cultured on AMP-free culture medium during single-cell live imaging. Pre-coating of the spores with TC19, TC84, and BP2 had no effect on the germination process, and variably affected the burst time and generation time. However, the percentage of spores that burst and grew out into vegetative cells was drastically lower when pre-coated with Nisin A, suggesting a novel application potential of this lantibiotic peptide against spores. Our findings contribute to the understanding of AMPs and show the potential of AMPs as eventual therapeutic agents against spore-forming bacteria.
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Affiliation(s)
- Soraya Omardien
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Amsterdam, Netherlands
| | | | - Sebastian A Zaat
- Department of Medical Microbiology, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Stanley Brul
- Swammerdam Institute for Life Sciences, Department of Molecular Biology and Microbial Food Safety, University of Amsterdam, Amsterdam, Netherlands
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17
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Abstract
Germination of Clostridium difficile spores is a crucial early requirement for colonization of the gastrointestinal tract. Likewise, C. difficile cannot cause disease pathologies unless its spores germinate into metabolically active, toxin-producing cells. Recent advances in our understanding of C. difficile spore germination mechanisms indicate that this process is both complex and unique. This review defines unique aspects of the germination pathways of C. difficile and compares them to those of two other well-studied organisms, Bacillus anthracis and Clostridium perfringensC. difficile germination is unique, as C. difficile does not contain any orthologs of the traditional GerA-type germinant receptor complexes and is the only known sporeformer to require bile salts in order to germinate. While recent advances describing C. difficile germination mechanisms have been made on several fronts, major gaps in our understanding of C. difficile germination signaling remain. This review provides an updated, in-depth summary of advances in understanding of C. difficile germination and potential avenues for the development of therapeutics, and discusses the major discrepancies between current models of germination and areas of ongoing investigation.
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18
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Riley EP, Trinquier A, Reilly ML, Durchon M, Perera VR, Pogliano K, Lopez-Garrido J. Spatiotemporally regulated proteolysis to dissect the role of vegetative proteins during Bacillus subtilis sporulation: cell-specific requirement of σ H and σ A. Mol Microbiol 2018; 108:45-62. [PMID: 29363854 DOI: 10.1111/mmi.13916] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/19/2018] [Accepted: 01/21/2018] [Indexed: 11/27/2022]
Abstract
Sporulation in Bacillus subtilis is a paradigm of bacterial development, which involves the interaction between a larger mother cell and a smaller forespore. The mother cell and the forespore activate different genetic programs, leading to the production of sporulation-specific proteins. A critical gap in our understanding of sporulation is how vegetative proteins, made before sporulation initiation, contribute to spore formation. Here we present a system, spatiotemporally regulated proteolysis (STRP), which enables the rapid, developmentally regulated degradation of target proteins, thereby providing a suitable method to dissect the cell- and developmental stage-specific role of vegetative proteins. STRP has been used to dissect the role of two major vegetative sigma factors, σH and σA , during sporulation. The results suggest that σH is only required in predivisional cells, where it is essential for sporulation initiation, but that it is dispensable during subsequent steps of spore formation. However, evidence has been provided that σA plays different roles in the mother cell, where it replenishes housekeeping functions, and in the forespore, where it plays an unexpected role in promoting spore germination and outgrowth. Altogether, the results demonstrate that STRP has the potential to provide a comprehensive molecular dissection of every stage of sporulation, germination and outgrowth.
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Affiliation(s)
- Eammon P Riley
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Aude Trinquier
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Madeline L Reilly
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Marine Durchon
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Varahenage R Perera
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Kit Pogliano
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Javier Lopez-Garrido
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
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19
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Mutlu A, Trauth S, Ziesack M, Nagler K, Bergeest JP, Rohr K, Becker N, Höfer T, Bischofs IB. Phenotypic memory in Bacillus subtilis links dormancy entry and exit by a spore quantity-quality tradeoff. Nat Commun 2018; 9:69. [PMID: 29302032 PMCID: PMC5754360 DOI: 10.1038/s41467-017-02477-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 12/04/2017] [Indexed: 12/15/2022] Open
Abstract
Some bacteria, such as Bacillus subtilis, withstand starvation by forming dormant spores that revive when nutrients become available. Although sporulation and spore revival jointly determine survival in fluctuating environments, the relationship between them has been unclear. Here we show that these two processes are linked by a phenotypic “memory” that arises from a carry-over of molecules from the vegetative cell into the spore. By imaging life histories of individual B. subtilis cells using fluorescent reporters, we demonstrate that sporulation timing controls nutrient-induced spore revival. Alanine dehydrogenase contributes to spore memory and controls alanine-induced outgrowth, thereby coupling a spore’s revival capacity to the gene expression and growth history of its progenitors. A theoretical analysis, and experiments with signaling mutants exhibiting altered sporulation timing, support the hypothesis that such an intrinsically generated memory leads to a tradeoff between spore quantity and spore quality, which could drive the emergence of complex microbial traits. Bacillus subtilis withstands starvation by forming dormant spores that revive when nutrients become available. Here, Mutlu et al. show that sporulation timing controls spore revival through a phenotypic ‘memory’ that arises from the carry-over of a metabolic enzyme from the vegetative cell into the spore.
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Affiliation(s)
- Alper Mutlu
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | - Stephanie Trauth
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | - Marika Ziesack
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Center for Molecular Biology (ZMBH), University of Heidelberg, 69120, Heidelberg, Germany
| | - Katja Nagler
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany
| | - Jan-Philip Bergeest
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), 69120, Heidelberg, Germany.,Department of Bioinformatics and Functional Genomics, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Karl Rohr
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Institute of Pharmacy and Molecular Biotechnology (IPMB), 69120, Heidelberg, Germany.,Department of Bioinformatics and Functional Genomics, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Nils Becker
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Division of Theoretical Systems Biology, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Thomas Höfer
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany.,Division of Theoretical Systems Biology, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Ilka B Bischofs
- BioQuant Center of the University of Heidelberg, 69120, Heidelberg, Germany. .,Center for Molecular Biology (ZMBH), University of Heidelberg, 69120, Heidelberg, Germany. .,Max-Planck-Institute for Terrestrial Microbiology, 35043, Marburg, Germany.
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20
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Abstract
Dormant Bacillales and Clostridiales spores begin to grow when small molecules (germinants) trigger germination, potentially leading to food spoilage or disease. Germination-specific proteins sense germinants, transport small molecules, and hydrolyze specific bonds in cortex peptidoglycan and specific proteins. Major events in germination include (a) germinant sensing; (b) commitment to germinate; (c) release of spores' depot of dipicolinic acid (DPA); (d) hydrolysis of spores' peptidoglycan cortex; and (e) spore core swelling and water uptake, cell wall peptidoglycan remodeling, and restoration of core protein and inner spore membrane lipid mobility. Germination is similar between Bacillales and Clostridiales, but some species differ in how germinants are sensed and how cortex hydrolysis and DPA release are triggered. Despite detailed knowledge of the proteins and signal transduction pathways involved in germination, precisely what some germination proteins do and how they do it remain unclear.
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Affiliation(s)
- Peter Setlow
- Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut 06030-3305;
| | - Shiwei Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
| | - Yong-Qing Li
- Department of Physics, East Carolina University, Greenville, North Carolina 27858-4353;
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21
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Sinai L, Ben-Yehuda S. Commentary: Changes in Bacillus Spore Small Molecules, rRNA, Germination, and Outgrowth after Extended Sublethal Exposure to Various Temperatures: Evidence that Protein Synthesis Is Not Essential for Spore Germination. Front Microbiol 2016; 7:2043. [PMID: 28082954 PMCID: PMC5183584 DOI: 10.3389/fmicb.2016.02043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/05/2016] [Indexed: 12/04/2022] Open
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22
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Protein Synthesis during Germination: Shedding New Light on a Classical Question. J Bacteriol 2016; 198:3251-3253. [PMID: 27736794 DOI: 10.1128/jb.00721-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite over a century of research into the mystery of bacterial spore dormancy and germination, a key question remains unresolved: is protein synthesis required for germination? The development of more sophisticated techniques for assessing and preventing protein synthesis has renewed interest in this long-standing question in recent years. In this issue, Korza et al. (G. Korza, B. Setlow, L. Rao, Q. Li, and P. Setlow, J. Bacteriol 198:3254-3264, 2016, http://dx.doi.org/10.1128/JB.00583-16) address this with a novel approach. We discuss their results in the context of recently published data.
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