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Koli S, Shetty S. Ribosomal dormancy at the nexus of ribosome homeostasis and protein synthesis. Bioessays 2024; 46:e2300247. [PMID: 38769702 DOI: 10.1002/bies.202300247] [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: 12/28/2023] [Revised: 02/05/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024]
Abstract
Dormancy or hibernation is a non-proliferative state of cells with low metabolic activity and gene expression. Dormant cells sequester ribosomes in a translationally inactive state, called dormant/hibernating ribosomes. These dormant ribosomes are important for the preservation of ribosomes and translation shut-off. While recent studies attempted to elucidate their modes of formation, the regulation and roles of the diverse dormant ribosomal populations are still largely understudied. The mechanistic details of the formation of dormant ribosomes in stress and especially their disassembly during recovery remain elusive. In this review, we discuss the roles of dormant ribosomes and their potential regulatory mechanisms. Furthermore, we highlight the paradigms that need to be answered in the field of ribosomal dormancy.
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Affiliation(s)
- Saloni Koli
- Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India
| | - Sunil Shetty
- Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Tata Memorial Centre, Navi Mumbai, India
- Homi Bhabha National Institute, Mumbai, India
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2
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Chowdhury NB, Pokorzynski N, Rucks EA, Ouellette SP, Carabeo RA, Saha R. Metabolic model guided CRISPRi identifies a central role for phosphoglycerate mutase in Chlamydia trachomatis persistence. mSystems 2024:e0071724. [PMID: 38940523 DOI: 10.1128/msystems.00717-24] [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: 05/24/2024] [Accepted: 06/10/2024] [Indexed: 06/29/2024] Open
Abstract
Upon nutrient starvation, Chlamydia trachomatis serovar L2 (CTL) shifts from its normal growth to a non-replicating form, termed persistence. It is unclear if persistence reflects an adaptive response or a lack thereof. To understand this, transcriptomics data were collected for CTL grown under nutrient-replete and nutrient-starved conditions. Applying K-means clustering on transcriptomics data revealed a global transcriptomic rewiring of CTL under stress conditions in the absence of any canonical global stress regulator. This is consistent with previous data that suggested that CTL's stress response is due to a lack of an adaptive response mechanism. To investigate the impact of this on CTL metabolism, we reconstructed a genome-scale metabolic model of CTL (iCTL278) and contextualized it with the collected transcriptomics data. Using the metabolic bottleneck analysis on contextualized iCTL278, we observed that phosphoglycerate mutase (pgm) regulates the entry of CTL to the persistence state. Our data indicate that pgm has the highest thermodynamics driving force and lowest enzymatic cost. Furthermore, CRISPRi-driven knockdown of pgm in the presence or absence of tryptophan revealed the importance of this gene in modulating persistence. Hence, this work, for the first time, introduces thermodynamics and enzyme cost as tools to gain a deeper understanding on CTL persistence. IMPORTANCE This study uses a metabolic model to investigate factors that contribute to the persistence of Chlamydia trachomatis serovar L2 (CTL) under tryptophan and iron starvation conditions. As CTL lacks many canonical transcriptional regulators, the model was used to assess two prevailing hypotheses on persistence-that the chlamydial response to nutrient starvation represents a passive response due to the lack of regulators or that it is an active response by the bacterium. K-means clustering of stress-induced transcriptomics data revealed striking evidence in favor of the lack of adaptive (i.e., a passive) response. To find the metabolic signature of this, metabolic modeling pin-pointed pgm as a potential regulator of persistence. Thermodynamic driving force, enzyme cost, and CRISPRi knockdown of pgm supported this finding. Overall, this work introduces thermodynamic driving force and enzyme cost as a tool to understand chlamydial persistence, demonstrating how systems biology-guided CRISPRi can unravel complex bacterial phenomena.
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Affiliation(s)
- Niaz Bahar Chowdhury
- Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Nick Pokorzynski
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Elizabeth A Rucks
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P Ouellette
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Rey A Carabeo
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Rajib Saha
- Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
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Liu Y, Zhou H, Wang J, Liu S, Xie GJ, Liu BF, Xing D. Regulatory Mechanisms of Quorum Sensing System of Bacteria in Response to Chlorine and Ozone Disinfection. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38937254 DOI: 10.1021/acs.est.3c08305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Waterborne pathogens invariably present considerable threats to public health. The quorum sensing (QS) system is instrumental in coordinating bacterial growth and metabolisms. However, the responses and regulatory mechanisms of bacteria to various disinfection technologies through quorum sensing are still unclear. This study examines the inactivation effect of chlorination and ozonation on biofilms and planktonic cells of QS signaling-deficient mutants of Pseudomonas aeruginosa. Cell counting and viability assessment revealed that the combined disinfection of chlorine and ozone was the most effective for inactivating planktonic P. aeruginosa within 10 min of exposure. Additionally, microfluidic chip culture demonstrated that the secretion of quinolone signals escalated biofilms' disinfection resistance. Disinfection exposure significantly altered the gene expression of wild-type strains and QS signaling-deficient mutants. Moreover, the QS system triggered multilayered gene expression programs as a responsive protection to disinfectant exposure, including oxidative stress, ribosome synthesis, and the nutrient absorption of bacteria. These insights broaden our understanding of bacterial QS in response to disinfection, promising potential strategies toward efficient disinfection processes.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Huihui Zhou
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Jing Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Sitong Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Guo-Jun Xie
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
- School of Environment, Harbin Institute of Technology, Harbin 150090, P. R. China
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4
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Qi W, Jonker MJ, de Leeuw W, Brul S, ter Kuile BH. Role of RelA-synthesized (p)ppGpp and ROS-induced mutagenesis in de novo acquisition of antibiotic resistance in E. coli. iScience 2024; 27:109579. [PMID: 38617560 PMCID: PMC11015494 DOI: 10.1016/j.isci.2024.109579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/06/2024] [Accepted: 03/25/2024] [Indexed: 04/16/2024] Open
Abstract
The stringent response of bacteria to starvation and stress also fulfills a role in addressing the threat of antibiotics. Within this stringent response, (p)ppGpp, synthesized by RelA or SpoT, functions as a global alarmone. However, the effect of this (p)ppGpp on resistance development is poorly understood. Here, we show that knockout of relA or rpoS curtails resistance development against bactericidal antibiotics. The emergence of mutated genes associated with starvation and (p)ppGpp, among others, indicates the activation of stringent responses. The growth rate is decreased in ΔrelA-resistant strains due to the reduced ability to synthesize (p)ppGpp and the persistence of deacylated tRNA impeding protein synthesis. Sluggish cellular activity causes decreased production of reactive oxygen species (ROS), thereby reducing oxidative damage, leading to weakened DNA mismatch repair, potentially reducing the generation of mutations. These findings offer new targets for mitigating antibiotic resistance development, potentially achieved through inhibiting (p)ppGpp or ROS synthesis.
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Affiliation(s)
- Wenxi Qi
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Martijs J. Jonker
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Wim de Leeuw
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Stanley Brul
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Benno H. ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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Smith EL, Panis G, Woldemeskel SA, Viollier PH, Chien P, Goley ED. Regulation of the transcription factor CdnL promotes adaptation to nutrient stress in Caulobacter. PNAS NEXUS 2024; 3:pgae154. [PMID: 38650860 PMCID: PMC11034885 DOI: 10.1093/pnasnexus/pgae154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/03/2024] [Indexed: 04/25/2024]
Abstract
In response to nutrient deprivation, bacteria activate a conserved stress response pathway called the stringent response (SR). During SR activation in Caulobacter crescentus, SpoT synthesizes the secondary messengers guanosine 5'-diphosphate 3'-diphosphate and guanosine 5'-triphosphate 3'-diphosphate (collectively known as (p)ppGpp), which affect transcription by binding RNA polymerase (RNAP) to down-regulate anabolic genes. (p)ppGpp also impacts the expression of anabolic genes by controlling the levels and activities of their transcriptional regulators. In Caulobacter, a major regulator of anabolic genes is the transcription factor CdnL. If and how CdnL is controlled during the SR and why that might be functionally important are unclear. In this study, we show that CdnL is down-regulated posttranslationally during starvation in a manner dependent on SpoT and the ClpXP protease. Artificial stabilization of CdnL during starvation causes misregulation of ribosomal and metabolic genes. Functionally, we demonstrate that the combined action of SR transcriptional regulators and CdnL clearance allows for rapid adaptation to nutrient repletion. Moreover, cells that are unable to clear CdnL during starvation are outcompeted by wild-type cells when subjected to nutrient fluctuations. We hypothesize that clearance of CdnL during the SR, in conjunction with direct binding of (p)ppGpp and DksA to RNAP, is critical for altering the transcriptome in order to permit cell survival during nutrient stress.
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Affiliation(s)
- Erika L Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Gaël Panis
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Selamawit Abi Woldemeskel
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva 1211, Switzerland
| | - Peter Chien
- Department of Biochemistry and Molecular Biology, University of Massachusetts-Amherst, Amherst, MA 01003, USA
| | - Erin D Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Snoeck S, Guidi C, De Mey M. "Metabolic burden" explained: stress symptoms and its related responses induced by (over)expression of (heterologous) proteins in Escherichia coli. Microb Cell Fact 2024; 23:96. [PMID: 38555441 PMCID: PMC10981312 DOI: 10.1186/s12934-024-02370-9] [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: 12/01/2023] [Accepted: 03/18/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Engineering bacterial strains to redirect the metabolism towards the production of a specific product has enabled the development of industrial biotechnology. However, rewiring the metabolism can have severe implications for a microorganism, rendering cells with stress symptoms such as a decreased growth rate, impaired protein synthesis, genetic instability and an aberrant cell size. On an industrial scale, this is reflected in processes that are not economically viable. MAIN TEXT In literature, most stress symptoms are attributed to "metabolic burden", however the actual triggers and stress mechanisms involved are poorly understood. Therefore, in this literature review, we aimed to get a better insight in how metabolic engineering affects Escherichia coli and link the observed stress symptoms to its cause. Understanding the possible implications that chosen engineering strategies have, will help to guide the reader towards optimising the envisioned process more efficiently. CONCLUSION This review addresses the gap in literature and discusses the triggers and effects of stress mechanisms that can be activated when (over)expressing (heterologous) proteins in Escherichia coli. It uncovers that the activation of the different stress mechanisms is complex and that many are interconnected. The reader is shown that care has to be taken when (over)expressing (heterologous) proteins as the cell's metabolism is tightly regulated.
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Affiliation(s)
- Sofie Snoeck
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium
| | - Chiara Guidi
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium
| | - Marjan De Mey
- Department of Biotechnology, Centre for Synthetic Biology, Coupure Links 653, Gent, 9000, Belgium.
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Ding S, Liu C, Zhu Y, Li J, Shi G, Zhu A. Rare Earth-Carbon Dots Nanocomposite-Modified Glass Nanopipettes: Electro-Optical Detection of Bacterial ppGpp. Anal Chem 2024; 96:4521-4527. [PMID: 38442333 DOI: 10.1021/acs.analchem.3c05211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
As an important alarmone nucleotide, guanosine 3'-diphosphate-5'-diphosphate (ppGpp) can regulate the survival of bacteria under strict environmental conditions. Direct detection of ppGpp in bacteria with high sensitivity and selectivity is crucial for elucidating the role of ppGpp in bacterial stringent response. Herein, the terbium-carbon dots nanocomposite (CDs-Tb) modified glass nanopipet was developed for the recognition of ppGpp. The CDs-Tb in glass nanopipette preserved their fluorescence properties as well as the coordination capacity of Tb3+ toward ppGpp. The addition of ppGpp not only led to the fluorescence response of CDs-Tb but also triggered variations of surface charge inside the glass nanopipet, resulting in the ionic current response. Compared with nucleotides with similar structures, this method displayed good selectivity toward ppGpp. Moreover, the dual signals (fluorescence and ionic current) offered a built-in correction for potential interference. Apart from the high selectivity, the proposed method can determine the concentration of ppGpp from 10-13 to 10-7 M. Taking advantage of the significant analytical performance, we monitored ppGpp in Escherichia coli under different nutritional conditions and studied the relationship between ppGpp and DNA repair, which is helpful for overcoming antibiotic resistance and promoting the development of potential drugs for antibacterial treatment.
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Affiliation(s)
- Shushu Ding
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Chunyan Liu
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
| | - Yue Zhu
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Jinlong Li
- School of Pharmacy, Nantong University, 19 Qixiu Road, Nantong 226001, People's Republic of China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
| | - Anwei Zhu
- School of Chemistry and Molecular Engineering, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, 500 Dongchuan Road, Shanghai 200241, People's Republic of China
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8
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Handler S, Kirkpatrick CL. New layers of regulation of the general stress response sigma factor RpoS. Front Microbiol 2024; 15:1363955. [PMID: 38505546 PMCID: PMC10948607 DOI: 10.3389/fmicb.2024.1363955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 02/21/2024] [Indexed: 03/21/2024] Open
Abstract
The general stress response (GSR) sigma factor RpoS from Escherichia coli has emerged as one of the key paradigms for study of how numerous signal inputs are accepted at multiple levels into a single pathway for regulation of gene expression output. While many studies have elucidated the key pathways controlling the production and activity of this sigma factor, recent discoveries have uncovered still more regulatory mechanisms which feed into the network. Moreover, while the regulon of this sigma factor comprises a large proportion of the E. coli genome, the downstream expression levels of all the RpoS target genes are not identically affected by RpoS upregulation but respond heterogeneously, both within and between cells. This minireview highlights the most recent developments in our understanding of RpoS regulation and expression, in particular those which influence the regulatory network at different levels from previously well-studied pathways.
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Ghoshal M, Bechtel TD, Gibbons JG, McLandsborough L. Transcriptomic analysis using RNA sequencing and phenotypic analysis of Salmonella enterica after acid exposure for different time durations using adaptive laboratory evolution. Front Microbiol 2024; 15:1348063. [PMID: 38476938 PMCID: PMC10929716 DOI: 10.3389/fmicb.2024.1348063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 03/14/2024] Open
Abstract
Introduction This study is the final part of a two-part series that delves into the molecular mechanisms driving adaptive laboratory evolution (ALE) of Salmonella enterica in acid stress. The phenotypic and transcriptomic alterations in the acid-evolved lineages (EL) of Salmonella enterica serovar Enteritidis after 70 days of acid stress exposure were analyzed. Materials and methods The stability of phenotypic changes observed after 70 days in acetic acid was explored after stress removal using a newly developed evolutionary lineage EL5. Additionally, the impact of short-term acid stress on the previously adapted lineage EL4 was also examined. Results The results indicate that the elevated antibiotic minimum inhibitory concentration (MIC) observed after exposure to acetic acid for 70 days was lost when acid stress was removed. This phenomenon was observed against human antibiotics such as meropenem, ciprofloxacin, gentamicin, and streptomycin. The MIC of meropenem in EL4 on day 70 was 0.094 mM, which dropped to 0.032 mM when removed from acetic acid stress after day 70. However, after stress reintroduction, the MIC swiftly elevated, and within 4 days, it returned to 0.094 mM. After 20 more days of adaptation in acetic acid, the meropenem MIC increased to 0.125 mM. The other human antibiotics that were tested exhibited a similar trend. The MIC of acetic acid in EL4 on day 70 was observed to be 35 mM, which remained constant even after the removal of acetic acid stress. Readaptation of EL4 in acetic acid for 20 more days caused the acetic acid MIC to increase to 37 mM. Bacterial whole genome sequencing of EL5 revealed base substitutions in several genes involved in pathogenesis, such as the phoQ and wzc genes. Transcriptomic analysis of EL5 revealed upregulation of virulence, drug resistance, toxin-antitoxin, and iron metabolism genes. Unstable Salmonella small colony variants (SSCV) of S. Enteritidis were also observed in EL5 as compared to the wild-type unevolved S. Enteritidis. Discussion This study presents a comprehensive understanding of the evolution of the phenotypic, genomic, and transcriptomic changes in S. Enteritidis due to prolonged acid exposure through ALE.
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Affiliation(s)
- Mrinalini Ghoshal
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Tyler D. Bechtel
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - John G. Gibbons
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Lynne McLandsborough
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
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Qi W, Jonker MJ, Katsavelis D, de Leeuw W, Wortel M, Ter Kuile BH. The Effect of the Stringent Response and Oxidative Stress Response on Fitness Costs of De Novo Acquisition of Antibiotic Resistance. Int J Mol Sci 2024; 25:2582. [PMID: 38473832 DOI: 10.3390/ijms25052582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/12/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Resistance evolution during exposure to non-lethal levels of antibiotics is influenced by various stress responses of bacteria which are known to affect growth rate. Here, we aim to disentangle how the interplay between resistance development and associated fitness costs is affected by stress responses. We performed de novo resistance evolution of wild-type strains and single-gene knockout strains in stress response pathways using four different antibiotics. Throughout resistance development, the increase in minimum inhibitory concentration (MIC) is accompanied by a gradual decrease in growth rate, most pronounced in amoxicillin or kanamycin. By measuring biomass yield on glucose and whole-genome sequences at intermediate and final time points, we identified two patterns of how the stress responses affect the correlation between MIC and growth rate. First, single-gene knockout E. coli strains associated with reactive oxygen species (ROS) acquire resistance faster, and mutations related to antibiotic permeability and pumping out occur earlier. This increases the metabolic burden of resistant bacteria. Second, the ΔrelA knockout strain, which has reduced (p)ppGpp synthesis, is restricted in its stringent response, leading to diminished growth rates. The ROS-related mutagenesis and the stringent response increase metabolic burdens during resistance development, causing lower growth rates and higher fitness costs.
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Affiliation(s)
- Wenxi Qi
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Martijs J Jonker
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Drosos Katsavelis
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Wim de Leeuw
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Meike Wortel
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Benno H Ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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Wang Y, Bai Y, Zeng Q, Jiang Z, Liu Y, Wang X, Liu X, Liu C, Min W. Recent advances in the metabolic engineering and physiological opportunities for microbial synthesis of L-aspartic acid family amino acids: A review. Int J Biol Macromol 2023; 253:126916. [PMID: 37716660 DOI: 10.1016/j.ijbiomac.2023.126916] [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] [Received: 07/24/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
L-aspartic acid, L-threonine, L-isoleucine, l-lysine, and L-methionine constitute the l-aspartate amino acids (AFAAs). Except for L-aspartic acid, these are essential amino acids that cannot be synthesized by humans or animals themselves. E. coli and C. glutamicum are the main model organisms for AFAA production. It is necessary to reconstitute microbial cell factories and the physiological state of industrial fermentation cells for in-depth research into strains with higher AFAA production levels and optimal growth states. Considering that the anabolic pathways of the AFAAs and engineering modifications have rarely been reviewed in the latest progress, this work reviews the central metabolic pathways of two strains and strategies for the metabolic engineering of AFAA synthetic pathways. The challenges posed by microbial physiology in AFAA production and possible strategies to address them, as well as future research directions for constructing strains with high AFAA production levels, are discussed in this review article.
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Affiliation(s)
- Yusheng Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Yunlong Bai
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Qi Zeng
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Zeyuan Jiang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Yuzhe Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Xiyan Wang
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Xiaoting Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China
| | - Chunlei Liu
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China.
| | - Weihong Min
- College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, PR China.
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12
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Smith EL, Panis G, Woldemeskel SA, Viollier PH, Chien P, Goley ED. Regulation of the transcription factor CdnL promotes adaptation to nutrient stress in Caulobacter. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572625. [PMID: 38187569 PMCID: PMC10769358 DOI: 10.1101/2023.12.20.572625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
In response to nutrient deprivation, bacteria activate a conserved stress response pathway called the stringent response (SR). During SR activation in Caulobacter crescentus, SpoT synthesizes the secondary messengers (p)ppGpp, which affect transcription by binding RNA polymerase to downregulate anabolic genes. (p)ppGpp also impacts expression of anabolic genes by controlling the levels and activities of their transcriptional regulators. In Caulobacter, a major regulator of anabolic genes is the transcription factor CdnL. If and how CdnL is controlled during the SR and why that might be functionally important is unclear. Here, we show that CdnL is downregulated post-translationally during starvation in a manner dependent on SpoT and the ClpXP protease. Inappropriate stabilization of CdnL during starvation causes misregulation of ribosomal and metabolic genes. Functionally, we demonstrate that the combined action of SR transcriptional regulators and CdnL clearance allows for rapid adaptation to nutrient repletion. Moreover, cells that are unable to clear CdnL during starvation are outcompeted by wild-type cells when subjected to nutrient fluctuations. We hypothesize that clearance of CdnL during the SR, in conjunction with direct binding of (p)ppGpp and DksA to RNAP, is critical for altering the transcriptome in order to permit cell survival during nutrient stress.
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Affiliation(s)
- Erika L. Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205
| | - Gaäl Panis
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland, 1211
| | - Selamawit Abi Woldemeskel
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205
- BlueRock Therapeutics, Cambridge, Massachusetts, 02142 (current)
| | - Patrick H. Viollier
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland, 1211
| | - Peter Chien
- Department of Biochemistry and Molecular Biology, University of Massachusetts-Amherst, Amherst, Massachusetts, 01003
| | - Erin D. Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205
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13
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Bren A, Glass DS, Kohanim YK, Mayo A, Alon U. Tradeoffs in bacterial physiology determine the efficiency of antibiotic killing. Proc Natl Acad Sci U S A 2023; 120:e2312651120. [PMID: 38096408 PMCID: PMC10742385 DOI: 10.1073/pnas.2312651120] [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: 07/26/2023] [Accepted: 11/02/2023] [Indexed: 12/18/2023] Open
Abstract
Antibiotic effectiveness depends on a variety of factors. While many mechanistic details of antibiotic action are known, the connection between death rate and bacterial physiology is poorly understood. A common observation is that death rate in antibiotics rises linearly with growth rate; however, it remains unclear how other factors, such as environmental conditions and whole-cell physiological properties, affect bactericidal activity. To address this, we developed a high-throughput assay to precisely measure antibiotic-mediated death. We found that death rate is linear in growth rate, but the slope depends on environmental conditions. Growth under stress lowers death rate compared to nonstressed environments with similar growth rate. To understand stress's role, we developed a mathematical model of bacterial death based on resource allocation that includes a stress-response sector; we identify this sector using RNA-seq. Our model accurately predicts the minimal inhibitory concentration (MIC) with zero free parameters across a wide range of growth conditions. The model also quantitatively predicts death and MIC when sectors are experimentally modulated using cyclic adenosine monophosphate (cAMP), including protection from death at very low cAMP levels. The present study shows that different conditions with equal growth rate can have different death rates and establishes a quantitative relation between growth, death, and MIC that suggests approaches to improve antibiotic efficacy.
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Affiliation(s)
- Anat Bren
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot7610001, Israel
| | - David S. Glass
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Yael Korem Kohanim
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT06520
| | - Avi Mayo
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot7610001, Israel
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14
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Chowdhury NB, Pokorzynski N, Rucks EA, Ouellette SP, Carabeo RA, Saha R. Machine Learning and Metabolic Model Guided CRISPRi Reveals a Central Role for Phosphoglycerate Mutase in Chlamydia trachomatis Persistence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.18.572198. [PMID: 38187683 PMCID: PMC10769294 DOI: 10.1101/2023.12.18.572198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Upon nutrient starvation, Chlamydia trachomatis serovar L2 (CTL) shifts from its normal growth to a non-replicating form, termed persistence. It is unclear if persistence is an adaptive response or lack of it. To understand that transcriptomics data were collected for nutrient-sufficient and nutrient-starved CTL. Applying machine learning approaches on transcriptomics data revealed a global transcriptomic rewiring of CTL under stress conditions without having any global stress regulator. This indicated that CTL's stress response is due to lack of an adaptive response mechanism. To investigate the impact of this on CTL metabolism, we reconstructed a genome-scale metabolic model of CTL (iCTL278) and contextualized it with the collected transcriptomics data. Using the metabolic bottleneck analysis on contextualized iCTL278, we observed phosphoglycerate mutase (pgm) regulates the entry of CTL to the persistence. Later, pgm was found to have the highest thermodynamics driving force and lowest enzymatic cost. Furthermore, CRISPRi-driven knockdown of pgm and tryptophan starvation experiments revealed the importance of this gene in inducing persistence. Hence, this work, for the first time, introduced thermodynamics and enzyme-cost as tools to gain deeper understanding on CTL persistence.
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Affiliation(s)
- Niaz Bahar Chowdhury
- Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68508, USA
| | - Nick Pokorzynski
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Elizabeth A. Rucks
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Scot P. Ouellette
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Rey A. Carabeo
- Department of Pathology, Microbiology, and Immunology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Rajib Saha
- Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68508, USA
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15
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de Pedro-Jové R, Corral J, Rocafort M, Puigvert M, Azam FL, Vandecaveye A, Macho AP, Balsalobre C, Coll NS, Orellano E, Valls M. Gene expression changes throughout the life cycle allow a bacterial plant pathogen to persist in diverse environmental habitats. PLoS Pathog 2023; 19:e1011888. [PMID: 38113281 PMCID: PMC10763947 DOI: 10.1371/journal.ppat.1011888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/03/2024] [Accepted: 12/07/2023] [Indexed: 12/21/2023] Open
Abstract
Bacterial pathogens exhibit a remarkable ability to persist and thrive in diverse ecological niches. Understanding the mechanisms enabling their transition between habitats is crucial to control dissemination and potential disease outbreaks. Here, we use Ralstonia solanacearum, the causing agent of the bacterial wilt disease, as a model to investigate pathogen adaptation to water and soil, two environments that act as bacterial reservoirs, and compare this information with gene expression in planta. Gene expression in water resembled that observed during late xylem colonization, with an intriguing induction of the type 3 secretion system (T3SS). Alkaline pH and nutrient scarcity-conditions also encountered during late infection stages-were identified as the triggers for this T3SS induction. In the soil environment, R. solanacearum upregulated stress-responses and genes for the use of alternate carbon sources, such as phenylacetate catabolism and the glyoxylate cycle, and downregulated virulence-associated genes. We proved through gain- and loss-of-function experiments that genes associated with the oxidative stress response, such as the regulator OxyR and the catalase KatG, are key for bacterial survival in soil, as their deletion cause a decrease in culturability associated with a premature induction of the viable but non culturable state (VBNC). This work identifies essential factors necessary for R. solanacearum to complete its life cycle and is the first comprehensive gene expression analysis in all environments occupied by a bacterial plant pathogen, providing valuable insights into its biology and adaptation to unexplored habitats.
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Affiliation(s)
- Roger de Pedro-Jové
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Jordi Corral
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Mercedes Rocafort
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Marina Puigvert
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Fàtima Latif Azam
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Agustina Vandecaveye
- Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-UNR-CONICET), Rosario, Santa Fe, Argentina
| | - Alberto P. Macho
- Shanghai Centre for Plant Stress Biology, CAS Centre for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Carlos Balsalobre
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
| | - Núria S. Coll
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
| | - Elena Orellano
- Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-UNR-CONICET), Rosario, Santa Fe, Argentina
| | - Marc Valls
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
- Centre for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Catalonia, Spain
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16
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Cordell WT, Avolio G, Takors R, Pfleger BF. Milligrams to kilograms: making microbes work at scale. Trends Biotechnol 2023; 41:1442-1457. [PMID: 37271589 DOI: 10.1016/j.tibtech.2023.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 06/06/2023]
Abstract
If biomanufacturing can become a sustainable route for producing chemicals, it will provide a critical step in reducing greenhouse gas emissions to fight climate change. However, efforts to industrialize microbial synthesis of chemicals have met with varied success, due, in part, to challenges in translating laboratory successes to industrial scale. With a particular focus on Escherichia coli, this review examines the lessons learned when studying microbial physiology and metabolism under conditions that simulate large-scale bioreactors and methods to minimize cellular waste through reduction of maintenance energy, optimizing the stress response and minimizing culture heterogeneity. With general strategies to overcome these challenges, biomanufacturing process scale-up could be de-risked and the time and cost of bringing promising syntheses to market could be reduced.
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Affiliation(s)
- William T Cordell
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Gennaro Avolio
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart 70569, Germany
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart 70569, Germany
| | - Brian F Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; DOE Center Advanced Bioenergy and Bioproducts Innovation, University of Wisconsin-Madison, Madison, WI 53706, USA; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI 53706, USA.
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17
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Wan X, Chou WK, Brynildsen MP. Amino acids can deplete ATP and impair nitric oxide detoxification by Escherichia coli. Free Radic Biol Med 2023; 205:90-99. [PMID: 37253411 DOI: 10.1016/j.freeradbiomed.2023.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/18/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2023]
Abstract
Nitric oxide (·NO) is a prevalent antimicrobial that is known to damage iron-containing enzymes in amino acid (AA) biosynthesis pathways. With Escherichia coli, ·NO is detoxified in aerobic environments by Hmp, which is an enzyme that is synthesized de novo in response to ·NO. With this knowledgebase, it is expected that the availability of AAs in the extracellular environment would enhance ·NO detoxification, because AAs would foster translation of Hmp. However, we observed that ·NO detoxification by E. coli was far slower in populations grown and treated in the presence of AAs (AA+) in comparison to those grown and stressed in the absence of AAs (AA-). Further experiments revealed that AA+ populations had difficulty translating proteins under ·NO stress, and that ·NO activated the stringent response in AA+ populations. Additional work revealed significant ATP depletion in ·NO-stressed AA+ cultures that far exceeded that of ·NO-stressed AA- populations. Transcription, translation, and RelA were not found to be significant contributors to the ATP depletion observed, whereas AA import was implicated as a significant ATP consumption pathway. Alleviating ATP depletion while maintaining access to AAs partially restored ·NO detoxification, which suggested that ATP depletion contributed to the translational difficulties observed in ·NO-stressed AA+ populations. These data reveal an unexpected interaction within the ·NO response network of E. coli that stimulates a stringent response by RelA in conditions where AAs are plentiful.
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Affiliation(s)
- Xuanqing Wan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Wen Kang Chou
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
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18
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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.
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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.
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19
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Scott M, Hwa T. Shaping bacterial gene expression by physiological and proteome allocation constraints. Nat Rev Microbiol 2023; 21:327-342. [PMID: 36376406 PMCID: PMC10121745 DOI: 10.1038/s41579-022-00818-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2022] [Indexed: 11/16/2022]
Abstract
Networks of molecular regulators are often the primary objects of focus in the study of gene regulation, with the machinery of protein synthesis tacitly relegated to the background. Shifting focus to the constraints imposed by the allocation of protein synthesis flux reveals surprising ways in which the actions of molecular regulators are shaped by physiological demands. Using carbon catabolite repression as a case study, we describe how physiological constraints are sensed through metabolic fluxes and how flux-controlled regulation gives rise to simple empirical relations between protein levels and the rate of cell growth.
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Affiliation(s)
- Matthew Scott
- Department of Applied Mathematics, University of Waterloo, Waterloo, ON, Canada.
| | - Terence Hwa
- Department of Physics, University of California at San Diego, La Jolla, CA, USA.
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20
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Weaver JW, Proshkin S, Duan W, Epshtein V, Gowder M, Bharati BK, Afanaseva E, Mironov A, Serganov A, Nudler E. Control of transcription elongation and DNA repair by alarmone ppGpp. Nat Struct Mol Biol 2023; 30:600-607. [PMID: 36997761 PMCID: PMC10191844 DOI: 10.1038/s41594-023-00948-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/27/2023] [Indexed: 04/01/2023]
Abstract
Second messenger (p)ppGpp (collectively guanosine tetraphosphate and guanosine pentaphosphate) mediates bacterial adaptation to nutritional stress by modulating transcription initiation. More recently, ppGpp has been implicated in coupling transcription and DNA repair; however, the mechanism of ppGpp engagement remained elusive. Here we present structural, biochemical and genetic evidence that ppGpp controls Escherichia coli RNA polymerase (RNAP) during elongation via a specific site that is nonfunctional during initiation. Structure-guided mutagenesis renders the elongation (but not initiation) complex unresponsive to ppGpp and increases bacterial sensitivity to genotoxic agents and ultraviolet radiation. Thus, ppGpp binds RNAP at sites with distinct functions in initiation and elongation, with the latter being important for promoting DNA repair. Our data provide insights on the molecular mechanism of ppGpp-mediated adaptation during stress, and further highlight the intricate relationships between genome stability, stress responses and transcription.
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Affiliation(s)
- Jacob W Weaver
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Sergey Proshkin
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Wenqian Duan
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Vitaly Epshtein
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Manjunath Gowder
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA
| | - Binod K Bharati
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA
| | - Elena Afanaseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Alexander Mironov
- Engelhardt Institute of Molecular Biology, Russian Academy of Science, Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Moscow, Russia
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
| | - Evgeny Nudler
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.
- Howard Hughes Medical Institute, New York University School of Medicine, New York, NY, USA.
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21
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Ahmad S, Gordon IJ, Tsang KK, Alexei AG, Sychantha D, Colautti J, Trilesky SL, Kim Y, Wang B, Whitney JC. Identification of a broadly conserved family of enzymes that hydrolyze (p)ppApp. Proc Natl Acad Sci U S A 2023; 120:e2213771120. [PMID: 36989297 PMCID: PMC10083569 DOI: 10.1073/pnas.2213771120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 02/25/2023] [Indexed: 03/30/2023] Open
Abstract
Bacteria produce a variety of nucleotide second messengers to adapt to their surroundings. Although chemically similar, the nucleotides guanosine penta- and tetraphosphate [(p)ppGpp] and adenosine penta- and tetraphosphate [(p)ppApp] have distinct functions in bacteria. (p)ppGpp mediates survival under nutrient-limiting conditions and its intracellular levels are regulated by synthetases and hydrolases belonging to the RelA-SpoT homolog (RSH) family of enzymes. By contrast, (p)ppApp is not known to be involved in nutrient stress responses and is synthesized by RSH-resembling toxins that inhibit the growth of bacterial cells. However, it remains unclear whether there exists a family of hydrolases that specifically act on (p)ppApp to reverse its toxic effects. Here, we present the structure and biochemical characterization of adenosine 3'-pyrophosphohydrolase 1 (Aph1), the founding member of a monofunctional (p)ppApp hydrolase family of enzymes. Our work reveals that Aph1 adopts a histidine-aspartate (HD)-domain fold characteristic of phosphohydrolase metalloenzymes and its activity mitigates the growth inhibitory effects of (p)ppApp-synthesizing toxins. Using an informatic approach, we identify over 2,000 putative (p)ppApp hydrolases that are widely distributed across bacterial phyla and found in diverse genomic contexts, and we demonstrate that 12 representative members hydrolyze ppApp. In addition, our in silico analyses reveal a unique molecular signature that is specific to (p)ppApp hydrolases, and we show that mutation of two residues within this signature broadens the specificity of Aph1 to promiscuously hydrolyze (p)ppGpp in vitro. Overall, our findings indicate that like (p)ppGpp hydrolases, (p)ppApp hydrolases are widespread in bacteria and may play important and underappreciated role(s) in bacterial physiology.
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Affiliation(s)
- Shehryar Ahmad
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Isis J. Gordon
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX75235
| | - Kara K. Tsang
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - Andrea G. Alexei
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - David Sychantha
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Jake Colautti
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Sarah L. Trilesky
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Youngchang Kim
- Structural Biology Center, X-ray Science, Argonne National Laboratory, Argonne, IL60439
| | - Boyuan Wang
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - John C. Whitney
- Michael DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
- David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, ONL8S 4K1, Canada
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22
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Huang Q, Szebenyi DME. The alarmone ppGpp selectively inhibits the isoform A of the human small GTPase Sar1. Proteins 2023; 91:518-531. [PMID: 36369712 DOI: 10.1002/prot.26445] [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: 08/10/2022] [Revised: 10/17/2022] [Accepted: 11/03/2022] [Indexed: 11/15/2022]
Abstract
Transport of newly synthesized proteins from endoplasmic reticulum (ER) to Golgi is mediated by coat protein complex II (COPII). The assembly and disassembly of COPII vesicles is regulated by the molecular switch Sar1, which is a small GTPase and a component of COPII. Usually a small GTPase binds GDP (inactive form) or GTP (active form). Mammals have two Sar1 isoforms, Sar1a and Sar1b, that have approximately 90% sequence identity. Some experiments demonstrated that these two isoforms had distinct but overlapping functions. Here we found another instance of differing behavior: the alarmone ppGpp could bind to and inhibit the GTPase activity of human Sar1a but could not inhibit the GTPase activity of human Sar1b. The crystal structures of Sar1a⋅ppGpp and Sar1b⋅GDP have been determined. Superposition of the structures shows that ppGpp binds to the nucleotide-binding pocket, its guanosine base, ribose ring and 5'-diphosphate occupying nearly the same positions as for GDP. However, its 3'-diphosphate points away from the active site and, hence, away from the surface of the protein. The overall structure of Sar1a⋅ppGpp is more similar to Sar1b⋅GDP than to Sar1b⋅GTP. We also find that the Asp140-Arg138-water-ligand interaction net is important for the binding of ppGpp to Sar1a. This study provides further evidence showing that there are biochemical differences between the Sar1a and Sar1b isoforms of Sar1.
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Affiliation(s)
- Qingqiu Huang
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York, USA
| | - Doletha M E Szebenyi
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York, USA
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23
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Ospino K, Spira B. Glyphosate affects persistence and tolerance but not antibiotic resistance. BMC Microbiol 2023; 23:61. [PMID: 36882692 PMCID: PMC9990207 DOI: 10.1186/s12866-023-02804-1] [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: 12/09/2022] [Accepted: 02/21/2023] [Indexed: 03/09/2023] Open
Abstract
Glyphosate is a herbicide widely used in food production that blocks the synthesis of aromatic amino acids in plants and in microorganisms and also induces the accumulation of the alarmone (p)ppGpp. The purpose of this study was to investigate whether glyphosate affects the resistance, tolerance or persistence of bacteria towards three different classes of antibiotics and the possible role of (p)ppGpp in this activity. Glyphosate did not affect the minimum inhibitory concentration of the tested antibiotics, but enhanced bacterial tolerance and/or persistence towards them. The upshift in ciprofloxacin and kanamycin tolerance was partially dependent on the presence of relA that promotes (p)ppGpp accumulation in response to glyphosate. Conversely, the strong increase in ampicillin tolerance caused by glyphosate was independent of relA. We conclude that by inducing aromatic amino acid starvation glyphosate contributes to the temporary increase in E. coli tolerance or persistence, but does not affect antibiotic resistance.
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Affiliation(s)
- Katia Ospino
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Beny Spira
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil.
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24
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Protein-Ligand Interactions in Scarcity: The Stringent Response from Bacteria to Metazoa, and the Unanswered Questions. Int J Mol Sci 2023; 24:ijms24043999. [PMID: 36835415 PMCID: PMC9965611 DOI: 10.3390/ijms24043999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/06/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
The stringent response, originally identified in Escherichia coli as a signal that leads to reprogramming of gene expression under starvation or nutrient deprivation, is now recognized as ubiquitous in all bacteria, and also as part of a broader survival strategy in diverse, other stress conditions. Much of our insight into this phenomenon derives from the role of hyperphosphorylated guanosine derivatives (pppGpp, ppGpp, pGpp; guanosine penta-, tetra- and tri-phosphate, respectively) that are synthesized on starvation cues and act as messengers or alarmones. These molecules, collectively referred to here as (p)ppGpp, orchestrate a complex network of biochemical steps that eventually lead to the repression of stable RNA synthesis, growth, and cell division, while promoting amino acid biosynthesis, survival, persistence, and virulence. In this analytical review, we summarize the mechanism of the major signaling pathways in the stringent response, consisting of the synthesis of the (p)ppGpp, their interaction with RNA polymerase, and diverse factors of macromolecular biosynthesis, leading to differential inhibition and activation of specific promoters. We also briefly touch upon the recently reported stringent-like response in a few eukaryotes, which is a very disparate mechanism involving MESH1 (Metazoan SpoT Homolog 1), a cytosolic NADPH phosphatase. Lastly, using ppGpp as an example, we speculate on possible pathways of simultaneous evolution of alarmones and their multiple targets.
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25
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Termination factor Rho mediates transcriptional reprogramming of Bacillus subtilis stationary phase. PLoS Genet 2023; 19:e1010618. [PMID: 36735730 PMCID: PMC9931155 DOI: 10.1371/journal.pgen.1010618] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/15/2023] [Accepted: 01/14/2023] [Indexed: 02/04/2023] Open
Abstract
Transcription termination factor Rho is known for its ubiquitous role in suppression of pervasive, mostly antisense, transcription. In the model Gram-positive bacterium Bacillus subtilis, de-repression of pervasive transcription by inactivation of rho revealed the role of Rho in the regulation of post-exponential differentiation programs. To identify other aspects of the regulatory role of Rho during adaptation to starvation, we have constructed a B. subtilis strain (Rho+) that expresses rho at a relatively stable high level in order to compensate for its decrease in the wild-type cells entering stationary phase. The RNAseq analysis of Rho+, WT and Δrho strains (expression profiles can be visualized at http://genoscapist.migale.inrae.fr/seb_rho/) shows that Rho over-production enhances the termination efficiency of Rho-sensitive terminators, thus reducing transcriptional read-through and antisense transcription genome-wide. Moreover, the Rho+ strain exhibits global alterations of sense transcription with the most significant changes observed for the AbrB, CodY, and stringent response regulons, forming the pathways governing the transition to stationary phase. Subsequent physiological analyses demonstrated that maintaining rho expression at a stable elevated level modifies stationary phase-specific physiology of B. subtilis cells, weakens stringent response, and thereby negatively affects the cellular adaptation to nutrient limitations and other stresses, and blocks the development of genetic competence and sporulation. These results highlight the Rho-specific termination of transcription as a novel element controlling stationary phase. The release of this control by decreasing Rho levels during the transition to stationary phase appears crucial for the functionality of complex gene networks ensuring B. subtilis survival in stationary phase.
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Esteban-Torres M, Ruiz L, Rossini V, Nally K, van Sinderen D. Intracellular glycogen accumulation by human gut commensals as a niche adaptation trait. Gut Microbes 2023; 15:2235067. [PMID: 37526383 PMCID: PMC10395257 DOI: 10.1080/19490976.2023.2235067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 07/06/2023] [Indexed: 08/02/2023] Open
Abstract
The human gut microbiota is a key contributor to host metabolism and physiology, thereby impacting in various ways on host health. This complex microbial community has developed many metabolic strategies to colonize, persist and survive in the gastrointestinal environment. In this regard, intracellular glycogen accumulation has been associated with important physiological functions in several bacterial species, including gut commensals. However, the role of glycogen storage in shaping the composition and functionality of the gut microbiota offers a novel perspective in gut microbiome research. Here, we review what is known about the enzymatic machinery and regulation of glycogen metabolism in selected enteric bacteria, while we also discuss its potential impact on colonization and adaptation to the gastrointestinal tract. Furthermore, we survey the presence of such glycogen biosynthesis pathways in gut metagenomic data to highlight the relevance of this metabolic trait in enhancing survival in the highly competitive and dynamic gut ecosystem.
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Affiliation(s)
- Maria Esteban-Torres
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
| | - Lorena Ruiz
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias, IPLA-CSIC, Villaviciosa, Spain
- Functionality and Ecology of Benefitial Microbes (MicroHealth Group), Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain
| | - Valerio Rossini
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Ken Nally
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Douwe van Sinderen
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- School of Microbiology, University College Cork, Cork, Ireland
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Wagley S. The Viable but Non-Culturable (VBNC) State in Vibrio Species: Why Studying the VBNC State Now Is More Exciting than Ever. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1404:253-268. [PMID: 36792880 DOI: 10.1007/978-3-031-22997-8_13] [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] [Indexed: 02/17/2023]
Abstract
During periods that are not conducive for growth or when facing stressful conditions, Vibrios enter a dormant state called the Viable But Non-Culturable (VBNC) state. In this chapter, I will analyse the role of the VBNC state in Vibrio species survival and pathogenesis and the molecular mechanisms regulating this complex phenomenon. I will emphasise some of the novel findings that make studying the VBNC state now more exciting than ever and its significance in the epidemiology of these pathogens and critical role in food safety.
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Affiliation(s)
- Sariqa Wagley
- Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, Devon, UK.
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Lee JB, Kim SK, Han D, Yoon JW. Mutating both relA and spoT of enteropathogenic Escherichia coli E2348/69 attenuates its virulence and induces interleukin 6 in vivo. Front Microbiol 2023; 14:1121715. [PMID: 36937293 PMCID: PMC10017862 DOI: 10.3389/fmicb.2023.1121715] [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: 12/12/2022] [Accepted: 02/08/2023] [Indexed: 03/06/2023] Open
Abstract
Here, we report for the first time that disrupting both relA and spoT genes in enteropathogenic Escherichia coli E2348/69 can attenuate its virulence and significantly induce interleukin 6 (IL-6) in vivo. Our experimental analyses demonstrated that an E2348/69 ΔrelAΔspoT double mutant strain derepressed the expression of type IV bundle forming pilus (BFP) and repressed the expression of glutamate decarboxylase (GAD) and locus of enterocyte effacement (LEE). Whole genome-scale transcriptomic analysis revealed that 1,564 EPEC genes were differentially expressed in the ΔrelAΔspoT double mutant strain (cut-off > two-fold). Such depletion of relA and spoT attenuated the virulence of E2348/69 in a Caenorhabditis elegans infection model. Surprisingly, IL-6 was highly induced in porcine macrophages infected with the ΔrelAΔspoT double mutant strain compared to those with its wildtype strain. Coinciding with these in vitro results, in vivo murine peritoneal challenge assays showed high increase of IL-6 and improved bacterial clearance in response to infection by the ΔrelAΔspoT double mutant strain. Taken together, our data suggest that relA and spoT play an essential role in regulating biological processes during EPEC pathogenesis and that their depletion can affect host immune responses by inducing IL-6.
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Mu H, Han F, Wang Q, Wang Y, Dai X, Zhu M. Recent functional insights into the magic role of (p)ppGpp in growth control. Comput Struct Biotechnol J 2022; 21:168-175. [PMID: 36544478 PMCID: PMC9747358 DOI: 10.1016/j.csbj.2022.11.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Rapid growth and survival are two key traits that enable bacterial cells to thrive in their natural habitat. The guanosine tetraphosphate and pentaphosphate [(p)ppGpp], also known as "magic spot", is a key second messenger inside bacterial cells as well as chloroplasts of plants and green algae. (p)ppGpp not only controls various stages of central dogma processes (replication, transcription, ribosome maturation and translation) and central metabolism but also regulates various physiological processes such as pathogenesis, persistence, motility and competence. Under extreme conditions such as nutrient starvation, (p)ppGpp-mediated stringent response is crucial for the survival of bacterial cells. This mini-review highlights some of the very recent progress on the key role of (p)ppGpp in bacterial growth control in light of cellular resource allocation and cell size regulation. We also briefly discuss some recent functional insights into the role of (p)ppGpp in plants and green algae from the angle of growth and development and further discuss several important open directions for future studies.
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30
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Cesar S, Sun J, Huang KC. Cellular memory of rapid growth is sensitive to nutrient depletion during starvation. Front Microbiol 2022; 13:1016371. [DOI: 10.3389/fmicb.2022.1016371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/01/2022] [Indexed: 11/22/2022] Open
Abstract
Bacteria frequently encounter nutrient fluctuations in natural environments, yet we understand little about their ability to maintain physiological memory of previous food sources. Starvation is a particularly acute case, in which cells must balance adaptation to stresses with limited nutrient supply. Here, we show that Escherichia coli cells immediately accelerate and decelerate in growth upon transitions from spent to fresh media and vice versa, respectively, and memory of rapid growth can be maintained for many hours under constant flow of spent medium. However, after transient exposure of stationary-phase cells to fresh medium, subsequent aerobic incubation in increasingly spent medium led to lysis and limited growth when rejuvenated in fresh medium. Growth defects were avoided by incubation in anaerobic spent medium or water, suggesting that defects were caused by respiration during the process of nutrient depletion in spent medium. These findings highlight the importance of respiration for stationary phase survival and underscore the broad range of starvation outcomes depending on environmental history.
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Fernández-Vázquez J, Cabrer-Panes JD, Åberg A, Juárez A, Madrid C, Gaviria-Cantin T, Fernández-Coll L, Vargas-Sinisterra AF, Jiménez CJ, Balsalobre C. ppGpp, the General Stress Response Alarmone, Is Required for the Expression of the α-Hemolysin Toxin in the Uropathogenic Escherichia coli Isolate, J96. Int J Mol Sci 2022; 23:ijms232012256. [PMID: 36293122 PMCID: PMC9602796 DOI: 10.3390/ijms232012256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/08/2022] Open
Abstract
ppGpp is an intracellular sensor that, in response to different types of stress, coordinates the rearrangement of the gene expression pattern of bacteria to promote adaptation and survival to new environmental conditions. First described to modulate metabolic adaptive responses, ppGpp modulates the expression of genes belonging to very diverse functional categories. In Escherichia coli, ppGpp regulates the expression of cellular factors that are important during urinary tract infections. Here, we characterize the role of this alarmone in the regulation of the hlyCABDII operon of the UPEC isolate J96, encoding the toxin α-hemolysin that induces cytotoxicity during infection of bladder epithelial cells. ppGpp is required for the expression of the α-hemolysin encoded in hlyCABDII by stimulating its transcriptional expression. Prototrophy suppressor mutations in a ppGpp-deficient strain restore the α-hemolysin expression from this operon to wild-type levels, confirming the requirement of ppGpp for its expression. ppGpp stimulates hlyCABDII expression independently of RpoS, RfaH, Zur, and H-NS. The expression of hlyCABDII is promoted at 37 °C and at low osmolarity. ppGpp is required for the thermoregulation but not for the osmoregulation of the hlyCABDII operon. Studies in both commensal and UPEC isolates demonstrate that no UPEC specific factor is strictly required for the ppGpp-mediated regulation described. Our data further support the role of ppGpp participating in the coordinated regulation of the expression of bacterial factors required during infection.
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Affiliation(s)
- Jorge Fernández-Vázquez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Juan David Cabrer-Panes
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Anna Åberg
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Antonio Juárez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Cristina Madrid
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Tania Gaviria-Cantin
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Llorenç Fernández-Coll
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | | | - Carlos Jonay Jiménez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Carlos Balsalobre
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
- Correspondence: ; Tel.: +34-934-034-622
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Abstract
Since Jacques Monod's foundational work in the 1940s, investigators studying bacterial physiology have largely (but not exclusively) focused on the exponential phase of bacterial cultures, which is characterized by rapid growth and high biosynthesis activity in the presence of excess nutrients. However, this is not the predominant state of bacterial life. In nature, most bacteria experience nutrient limitation most of the time. In fact, investigators even prior to Monod had identified other aspects of bacterial growth, including what is now known as the stationary phase, when nutrients become limiting. This review will discuss how bacteria transition to growth arrest in response to nutrient limitation through changes in transcription, translation, and metabolism. We will then examine how these changes facilitate survival during potentially extended periods of nutrient limitation, with particular attention to the metabolic strategies that underpin bacterial longevity in this state.
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Affiliation(s)
- Jonathan Dworkin
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Caroline S Harwood
- Department of Microbiology, University of Washington, Seattle, Washington, USA;
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Bai K, Jiang N, Chen X, Xu X, Li J, Luo L. RNA-Seq Analysis Discovers the Critical Role of Rel in ppGpp Synthesis, Pathogenicity, and the VBNC State of Clavibacter michiganensis. PHYTOPATHOLOGY 2022; 112:1844-1858. [PMID: 35341314 DOI: 10.1094/phyto-01-22-0023-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The viable but nonculturable (VBNC) state is a unique survival strategy of bacteria in response to stress conditions. It was confirmed that Clavibacter michiganensis, the causal agent of bacterial canker in tomato, could be induced into the VBNC state by exposure to CuSO4 in an oligotrophic solution. RNA-sequencing analysis was used to monitor the mechanisms of the VBNC state during CuSO4 induction in C. michiganensis. The results identified that numerous genes involved in stringent response, copper resistance, and stress resistance were upregulated, and some involved in cell division were downregulated significantly. The study investigated the importance of Rel, which is an essential enzyme in the synthesis of the molecular alarmone ppGpp, via the generation of a Δrel mutant and its complementation strain. Biological characterization revealed that deficiency of rel reduced the bacterial growth, production of exopolysaccharides, and pathogenicity as well as ppGpp production. The Δrel mutant increased the sensitivity to environmental stress, exhibiting reduced growth on minimal media and a propensity to enter the VBNC state in response to CuSO4. These findings have important implications for the understanding of survival mechanism and management of C. michiganensis and other phytopathogenic bacteria.
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Affiliation(s)
- Kaihong Bai
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Na Jiang
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xing Chen
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Xiaoli Xu
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Jianqiang Li
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
| | - Laixin Luo
- Department of Plant Pathology, China Agricultural University, Beijing Key Laboratory of Seed Disease Testing and Control, MOA Key Lab of Pest Monitoring and Green Management, Beijing, 100193, P.R. China
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Berkvens A, Chauhan P, Bruggeman FJ. Integrative biology of persister cell formation: molecular circuitry, phenotypic diversification and fitness effects. JOURNAL OF THE ROYAL SOCIETY, INTERFACE 2022; 19:20220129. [PMID: 36099930 PMCID: PMC9470271 DOI: 10.1098/rsif.2022.0129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microbial populations often contain persister cells, which reduce the extinction risk upon sudden stresses. Persister cell formation is deeply intertwined with physiology. Due to this complexity, it cannot be satisfactorily understood by focusing only on mechanistic, physiological or evolutionary aspects. In this review, we take an integrative biology perspective to identify common principles of persister cell formation, which might be applicable across evolutionary-distinct microbes. Persister cells probably evolved to cope with a fundamental trade-off between cellular stress and growth tasks, as any biosynthetic resource investment in growth-supporting proteins is at the expense of stress tasks and vice versa. Natural selection probably favours persister cell subpopulation formation over a single-phenotype strategy, where each cell is prepared for growth and stress to a suboptimal extent, since persister cells can withstand harsher environments and their coexistence with growing cells leads to a higher fitness. The formation of coexisting phenotypes requires bistable molecular circuitry. Bistability probably emerges from growth-modulated, positive feedback loops in the cell's growth versus stress control network, involving interactions between sigma factors, guanosine pentaphosphate and toxin-antitoxin (TA) systems. We conclude that persister cell formation is most likely a response to a sudden reduction in growth rate, which can be achieved by antibiotic addition, nutrient starvation, sudden stresses, nutrient transitions or activation of a TA system.
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Affiliation(s)
- Alicia Berkvens
- Systems Biology Lab, AIMMS, VU University, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
| | - Priyanka Chauhan
- Systems Biology Lab, AIMMS, VU University, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
| | - Frank J Bruggeman
- Systems Biology Lab, AIMMS, VU University, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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Wang H, Wang X, Wang L, Lu Z. Nutritional stress induced intraspecies competition revealed by transcriptome analysis in Sphingomonas melonis TY. Appl Microbiol Biotechnol 2022; 106:5675-5686. [PMID: 35927333 DOI: 10.1007/s00253-022-12097-5] [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] [Received: 04/06/2022] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 11/26/2022]
Abstract
Bacteria have developed various mechanisms by which they can compete or cooperate with other bacteria. This study showed that in the cocultures of wild-type Sphingomonas melonis TY and its isogenic mutant TYΔndpD grow with nicotine, the former can outcompete the latter. TYΔndpD undergoes growth arrest after four days when cocultured with wild-type TY, whereas the coculture has just entered a stationary phase and the substrate was nearly depleted, and the interaction between the two related strains was revealed by transcriptomic analysis. Analysis of the differential expression genes indicated that wild-type TY inhibited the growth of TYΔndpD mainly through toxin-antitoxin (TA) systems. The four upregulated antitoxin coding genes belong to type II TA systems in which the bactericidal effect of the cognate toxin was mainly through inhibition of translation or DNA replication, whereas wild-type TY with upregulated antitoxin genes can regenerate cognate immunity protein continuously and thus prevent the lethal action of toxin to itself. In addition, colicin-mediated antibacterial activity against closely related species may also be involved in the competition between wild-type TY and TYΔndpD under nutritional stress. Moreover, upregulation of carbon and nitrogen catabolism related-, stress response related-, DNA repair related-, and DNA replication-related genes in wild-type TY showed that it triggered a series of response mechanisms when facing dual stress of competition from isogenic mutant cells and nutritional limitation. Thus, we proposed that S. melonis TY employed the TA systems and colicin to compete with TYΔndpD under nutritional stress, thereby maximally acquiring and exploiting finite resources. KEY POINTS: • Cross-feeding between isogenic mutants and the wild-type strain. • Nutrition stress caused a shift from cooperation to competition. • TYΔndpD undergo growth arrest by exogenous and endogenous toxins.
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Affiliation(s)
- Haixia Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xiaoyu Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Lvjing Wang
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Zhenmei Lu
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.
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Regulatory effect of polyamines and indole on expression of stress adaptation genes in <i> Escherichia coli </i>. ACTA BIOMEDICA SCIENTIFICA 2022. [DOI: 10.29413/abs.2022-7.3.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background. Indole and polyamines are involved in the regulation of physiological processes in bacteria associated with adaptation to stress, biofilm formation, antibiotic tolerance, and bacterial persistence. However, the molecular targets and mechanisms of action of these metabolites are still poorly understood. In this work, we studied the effect of polyamines and indole on the expression of such genes as: rpoS, relA, and spoT, encoding regulators of the general stress responses and starvation; hns and stpA, encoding global regulators of gene expression; rmf, yqjD, hpf, raiA, rsfS, sra, ettA, encoding ribosome hibernation factors.The aim. To study the regulatory effects of polyamines and indole on the expression of these genes, which are responsible for the adaptation of Escherichia coli to stress.Materials and methods. We used strains of E. coli in this study. The amount of polyamines was studied by thin layer chromatography. The indole concentration was determined by high performance liquid chromatography. Gene expression was studied using real-time RT-PCR.Results. The addition of polyamines putrescine, cadaverine and spermidine to the medium stimulated the expression of all the studied genes. The maximal stimulation was observed at the stationary phase mostly. Putrescine and spermidine had the most significant effect. At 24 h of cultivation, an equimolar conversion of exogenous tryptophan into indole was showed. At this time, the expression of two genes – rmf and raiA – increased.Conclusions. We have shown that polyamines upregulate the expression of all the studied genes at the transcriptional level. The stimulating effect is specific for the phase of the batch culture and the type of polyamine. Indole has a positive effect on the expression of the rmf and raiA genes.
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Aimbetov R, Ogryzko V. Proteomic profiling of the carbon-starved Escherichia coli reveals upregulation of stress-inducible pathways implicated in biological adhesion and methylglyoxal metabolism. Res Microbiol 2022; 173:103968. [PMID: 35738311 DOI: 10.1016/j.resmic.2022.103968] [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: 03/22/2022] [Accepted: 06/15/2022] [Indexed: 10/18/2022]
Abstract
Starvation in bacteria is a complex adaptive response to deprivation of nutrients that has been shown to implicate a number of stress networks that modulate pathogenicity and antibiotic resistance. Starvation in nature is qualitatively different from in-culture late stationary phase energy source depletion. To look into proteome-level alterations elicited by complete elimination of carbon source, we used Escherichia coli HT115-derived SLE1 strain cells and a combination of label-free and metabolic isotope labeling approaches. We isolated pathways differentially affected by carbon starvation and observed robust upregulation of proteins implicated in networks belonging to Gene Ontology terms 'Biological adhesion' and 'Methylglyoxal metabolism'.
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Affiliation(s)
- Rakhan Aimbetov
- Nazarbayev University, 53 Kabanbay batyr avenue, 010000, Nur-Sultan, Kazakhstan.
| | - Vasily Ogryzko
- UMR 8126, Institut Gustave Roussy, 114 rue Edouard Vaillant, 94805, Villejuif, France
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38
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Khaova EA, Kashevarova NM, Tkachenko AG. Ribosome Hibernation: Molecular Strategy of Bacterial Survival (Review). APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822030061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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39
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Transcriptomic profiling of Escherichia coli K-12 in response to a compendium of stressors. Sci Rep 2022; 12:8788. [PMID: 35610252 PMCID: PMC9130244 DOI: 10.1038/s41598-022-12463-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 05/05/2022] [Indexed: 11/09/2022] Open
Abstract
Environmental perturbations impact multiple cellular traits, including gene expression. Bacteria respond to these stressful situations through complex gene interaction networks, thereby inducing stress tolerance and survival of cells. In this paper, we study the response mechanisms of E. coli when exposed to different environmental stressors via differential expression and co-expression analysis. Gene co-expression networks were generated and analyzed via Weighted Gene Co-expression Network Analysis (WGCNA). Based on the gene co-expression networks, genes with similar expression profiles were clustered into modules. The modules were analysed for identification of hub genes, enrichment of biological processes and transcription factors. In addition, we also studied the link between transcription factors and their differentially regulated targets to understand the regulatory mechanisms involved. These networks validate known gene interactions and provide new insights into genes mediating transcriptional regulation in specific stress environments, thus allowing for in silico hypothesis generation.
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40
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Cellular perception of growth rate and the mechanistic origin of bacterial growth law. Proc Natl Acad Sci U S A 2022; 119:e2201585119. [PMID: 35544692 PMCID: PMC9171811 DOI: 10.1073/pnas.2201585119] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Many cellular activities in bacteria are organized according to their growth rate. The notion that ppGpp measures the cell’s growth rate is well accepted in the field of bacterial physiology. However, despite decades of interrogation and the identification of multiple molecular interactions that connects ppGpp to some aspects of cell growth, we lack a system-level, quantitative picture of how this alleged “measurement” is performed. Through quantitative experiments, we show that the ppGpp pool responds inversely to the rate of translational elongation in Escherichia coli. Together with its roles in inhibiting ribosome biogenesis and activity, ppGpp closes a key regulatory circuit that enables the cell to perceive and control the rate of its growth across conditions. The celebrated linear growth law relating the ribosome content and growth rate emerges as a consequence of keeping a supply of ribosome reserves while maintaining elongation rate in slow growth conditions. Further analysis suggests the elongation rate itself is detected by sensing the ratio of dwelling and translocating ribosomes, a strategy employed to collapse the complex, high-dimensional dynamics of the molecular processes underlying cell growth to perceive the physiological state of the whole.
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Abstract
Temperature impacts biological systems across all length and timescales. Cells and the enzymes that comprise them respond to temperature fluctuations on short timescales, and temperature can affect protein folding, the molecular composition of cells, and volume expansion. Entire ecosystems exhibit temperature-dependent behaviors, and global warming threatens to disrupt thermal homeostasis in microbes that are important for human and planetary health. Intriguingly, the growth rate of most species follows the Arrhenius law of equilibrium thermodynamics, with an activation energy similar to that of individual enzymes but with maximal growth rates and over temperature ranges that are species specific. In this review, we discuss how the temperature dependence of critical cellular processes, such as the central dogma and membrane fluidity, contributes to the temperature dependence of growth. We conclude with a discussion of adaptation to temperature shifts and the effects of temperature on evolution and on the properties of microbial ecosystems.
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Affiliation(s)
- Benjamin D Knapp
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA;
| | - Kerwyn Casey Huang
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA; .,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA.,Chan Zuckerberg Biohub, San Francisco, California, USA
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42
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Reyes-González D, De Luna-Valenciano H, Utrilla J, Sieber M, Peña-Miller R, Fuentes-Hernández A. Dynamic proteome allocation regulates the profile of interaction of auxotrophic bacterial consortia. ROYAL SOCIETY OPEN SCIENCE 2022; 9:212008. [PMID: 35592760 PMCID: PMC9066302 DOI: 10.1098/rsos.212008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/25/2022] [Indexed: 05/03/2023]
Abstract
Microbial ecosystems are composed of multiple species in constant metabolic exchange. A pervasive interaction in microbial communities is metabolic cross-feeding and occurs when the metabolic burden of producing costly metabolites is distributed between community members, in some cases for the benefit of all interacting partners. In particular, amino acid auxotrophies generate obligate metabolic inter-dependencies in mixed populations and have been shown to produce a dynamic profile of interaction that depends upon nutrient availability. However, identifying the key components that determine the pair-wise interaction profile remains a challenging problem, partly because metabolic exchange has consequences on multiple levels, from allocating proteomic resources at a cellular level to modulating the structure, function and stability of microbial communities. To evaluate how ppGpp-mediated resource allocation drives the population-level profile of interaction, here we postulate a multi-scale mathematical model that incorporates dynamics of proteome partition into a population dynamics model. We compare our computational results with experimental data obtained from co-cultures of auxotrophic Escherichia coli K12 strains under a range of amino acid concentrations and population structures. We conclude by arguing that the stringent response promotes cooperation by inhibiting the growth of fast-growing strains and promoting the synthesis of metabolites essential for other community members.
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Affiliation(s)
- D. Reyes-González
- Synthetic Biology Program, Center for Genomic Sciences, Universidad Autónoma de México, 62220 Cuernavaca, Mexico
| | - H. De Luna-Valenciano
- Synthetic Biology Program, Center for Genomic Sciences, Universidad Autónoma de México, 62220 Cuernavaca, Mexico
- Systems Biology Program, Center for Genomic Sciences, Universidad Nacional Autónoma de México, 62210 Cuernavaca, Mexico
| | - J. Utrilla
- Synthetic Biology Program, Center for Genomic Sciences, Universidad Autónoma de México, 62220 Cuernavaca, Mexico
| | - M. Sieber
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
| | - R. Peña-Miller
- Systems Biology Program, Center for Genomic Sciences, Universidad Nacional Autónoma de México, 62210 Cuernavaca, Mexico
| | - A. Fuentes-Hernández
- Synthetic Biology Program, Center for Genomic Sciences, Universidad Autónoma de México, 62220 Cuernavaca, Mexico
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Yin WL, Xie ZY, Zeng YH, Zhang J, Long H, Ren W, Zhang X, Cai XN, Huang AY. Two (p)ppGpp Synthetase Genes, relA and spoT, Are Involved in Regulating Cell Motility, Exopolysaccharides Production, and Biofilm Formation of Vibrio alginolyticus. Front Microbiol 2022; 13:858559. [PMID: 35422789 PMCID: PMC9002329 DOI: 10.3389/fmicb.2022.858559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 02/28/2022] [Indexed: 12/14/2022] Open
Abstract
The stringent response mediated by the signal molecule (p)ppGpp is involved in response to multiple environmental stresses and control of various physiological processes. Studies have revealed that (p)ppGpp strongly affects the formation and maintenance of several bacterial biofilms. However, the specific regulatory roles of (p)ppGpp in biofilms, especially in the expression of genes related to cell motility and exopolysaccharides (EPSs) production, remain poorly understood. We recently reported two (p)ppGpp synthetase genes relA and spoT from the epizootic pathogen Vibrio alginolyticus. Herein, we found that the (p)ppGpp synthetase genes of V. alginolyticus contributed to biofilm formation at low cell density and biofilm detachment at high cell density, respectively, in polystyrene microtiter plates. Quantitative reverse transcription PCR (qRT-PCR) analysis revealed that the expression levels of both EPSs and motility associated genes were consistent with the development of biofilms. Besides, the (p)ppGpp synthetase gene spoT was found to be closely involved in the regulation of flagellum, smooth/translucent colony morphology and spotty pellicle at the air-liquid interface. Interestingly, pleiotropic phenotypes of ΔrelAΔspoT were similar to that of the rpoN (σ54) deletion mutant. Meanwhile, the absence of (p)ppGpp synthetase genes significantly reduced the expression levels of rpoN at low cell density, suggesting that (p)ppGpp may mediate the formation via positively affecting the alternative sigma factor RpoN. These findings allow us to propose (p)ppGpp as a crucial regulator for biofilm development in V. alginolyticus, in view of the regulatory roles of relA and spoT in cell motility and EPSs production.
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Affiliation(s)
- Wen-Liang Yin
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China
| | - Zhen-Yu Xie
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Yan-Hua Zeng
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China
| | - Ju Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China
| | - Hao Long
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China
| | - Wei Ren
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Xiang Zhang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Xiao-Ni Cai
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
| | - Ai-You Huang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, Hainan University, Haikou, China.,Laboratory of Development and Utilization of Marine Microbial Resource, Hainan University, Haikou, China.,College of Marine Sciences, Hainan University, Haikou, China.,Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Haikou, China
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44
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Mandel C, Yang H, Buchko GW, Abendroth J, Grieshaber N, Chiarelli T, Grieshaber S, Omsland A. Expression and structure of the Chlamydia trachomatis DksA ortholog. Pathog Dis 2022; 80:6564600. [PMID: 35388904 PMCID: PMC9126822 DOI: 10.1093/femspd/ftac007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/15/2022] [Accepted: 04/04/2022] [Indexed: 11/14/2022] Open
Abstract
Chlamydia trachomatis is a bacterial obligate intracellular parasite and a significant cause of human disease, including sexually transmitted infections and trachoma. The bacterial RNA polymerase-binding protein DksA is a transcription factor integral to the multicomponent bacterial stress response pathway known as the stringent response. The genome of C. trachomatis encodes a DksA ortholog (DksACt) that is maximally expressed at 15–20 h post infection, a time frame correlating with the onset of transition between the replicative reticulate body (RB) and infectious elementary body (EB) forms of the pathogen. Ectopic overexpression of DksACt in C. trachomatis prior to RB–EB transitions during infection of HeLa cells resulted in a 39.3% reduction in overall replication (yield) and a 49.6% reduction in recovered EBs. While the overall domain organization of DksACt is similar to the DksA ortholog of Escherichia coli (DksAEc), DksACt did not functionally complement DksAEc. Transcription of dksACt is regulated by tandem promoters, one of which also controls expression of nrdR, encoding a negative regulator of deoxyribonucleotide biosynthesis. The phenotype resulting from ectopic expression of DksACt and the correlation between dksACt and nrdR expression is consistent with a role for DksACt in the C. trachomatis developmental cycle.
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Affiliation(s)
- Cameron Mandel
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
| | - Hong Yang
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
| | - Garry W Buchko
- School of Molecular Biosciences, Washington State University, Pullman WA 99164, USA.,Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.,Seattle Structural Genomics Center for Infectious Disease, WA, USA
| | - Jan Abendroth
- Seattle Structural Genomics Center for Infectious Disease, WA, USA.,UCB, Bainbridge Island, WA 98110, USA
| | - Nicole Grieshaber
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Travis Chiarelli
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Scott Grieshaber
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Anders Omsland
- Paul G. Allen School for Global Health, Washington State University, Pullman, WA 99164, USA
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45
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Zou J, Peng B, Qu J, Zheng J. Are Bacterial Persisters Dormant Cells Only? Front Microbiol 2022; 12:708580. [PMID: 35185807 PMCID: PMC8847742 DOI: 10.3389/fmicb.2021.708580] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial persisters are a sub-population of phenotypic variants that tolerate high concentrations of antibiotics within the genetically homogeneous cells. They resume division upon the removal of drugs. Bacterial persistence is one of major causes of antibiotic treatment failure and recurrent infection. Cell dormancy, triggered by toxin/antitoxin pair, (p)ppGpp, SOS response and ATP levels, is known to be the mechanistic basis for persistence. However, recent studies have demonstrated that bacteria with active metabolism can maintain persistence by lowering intracellular antibiotic concentration via an efflux pump. Additionally, others and our work have showed that cell wall deficient bacteria (CWDB), including both L-form and spheroplasts that produced by β-lactam antibiotics, are associated with antibiotic persistence. They are not dormant cells as their cell walls have been completely damaged. In this review, we discuss the various types of persisters and highlight the contribution of non-walled bacteria on bacterial persistence.
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Affiliation(s)
- Jin Zou
- Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Southern University of Science and Technology, National Clinical Research Center for Infectious Diseases, Shenzhen, China.,Faculty of Health Sciences, University of Macau, Zhuhai, Macau SAR, China
| | - Bo Peng
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Jiuxin Qu
- Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Southern University of Science and Technology, National Clinical Research Center for Infectious Diseases, Shenzhen, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Zhuhai, Macau SAR, China.,Institute of Translational Medicine, University of Macau, Zhuhai, Macau SAR, China
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46
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Jin H, Lao YM, Zhou J, Cai ZH. Identification of a RelA/SpoT Homolog and Its Possible Role in the Accumulation of Astaxanthin in Haematococcus pluvialis. FRONTIERS IN PLANT SCIENCE 2022; 13:796997. [PMID: 35222463 PMCID: PMC8863741 DOI: 10.3389/fpls.2022.796997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
A RelA/SpoT homolog, HpRSH, was identified in Haematococcus pluvialis. HpRSH was found to catalyze Mg2+-dependent guanosine tetraphosphate (ppGpp) synthesis and Mn2+-dependent ppGpp hydrolysis, respectively. The transcription of HpRSH was significantly upregulated by environmental stresses, such as darkness, high light, nitrogen limitation, and salinity stress. The intracellular ppGpp level was also increased when exposed to these stresses. In addition, the classical initiator of stringent response, serine hydroxamate (SHX), was found to upregulate the transcription of HpRSH and increase the level of ppGpp. Moreover, stringent response induced by SHX or environmental stresses was proven to induce the accumulation of astaxanthin. These results indicated that stringent response regulatory system involved in the regulation of astaxanthin biosynthesis in H. pluvialis. Furthermore, stringent response was unable to induce astaxanthin accumulation under dark condition. This result implied that stringent response may regulate astaxanthin biosynthesis in a light-dependent manner.
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Affiliation(s)
- Hui Jin
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yong Min Lao
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
| | - Zhong Hua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
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47
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Li H, Nian J, Fang S, Guo M, Huang X, Zhang F, Wang Q, Zhang J, Bai J, Dong G, Xin P, Xie X, Chen F, Wang G, Wang Y, Qian Q, Zuo J, Chu J, Ma X. Regulation of nitrogen starvation responses by the alarmone (p)ppGpp in rice. J Genet Genomics 2022; 49:469-480. [DOI: 10.1016/j.jgg.2022.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 12/20/2022]
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48
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The Role of RelA and SpoT on ppGpp Production, Stress Response, Growth Regulation, and Pathogenicity in Xanthomonas campestris pv. campestris. Microbiol Spectr 2021; 9:e0205721. [PMID: 34935430 PMCID: PMC8693919 DOI: 10.1128/spectrum.02057-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The alarmone ppGpp plays an important role in the survival of bacteria by triggering the stringent response when exposed to environmental stress. Although Xanthomonas campestris pv. campestris (Xcc), which causes black rot disease in crucifers, is a representative species of Gram-negative phytopathogenic bacteria, relatively little is known regarding the factors influencing the stringent response in this species. However, previous studies in other Gram-negative bacteria have indicated that RelA and SpoT play a critical role in ppGpp synthesis. The current study found that these proteins also had an important role in Xcc, with a ΔrelAΔspoT double mutant being unable to produce ppGpp, resulting in changes to phenotype including reduced production of exopolysaccharides (EPS), exoenzymes, and biofilm, as well the loss of swarming motility and pathogenicity. The ppGpp-deficient mutant also exhibited greater sensitivity to environment stress, being almost incapable of growth on modified minimal medium (mMM) and having a much greater propensity to enter the viable but nonculturable (VBNC) state in response to oligotrophic conditions (0.85% NaCl). These findings much advance our understanding of the role of ppGpp in the biology of Xcc and could have important implications for more effective management of this important pathogen. IMPORTANCEXanthomonas campestris pv. campestris (Xcc) is a typical seedborne phytopathogenic bacterium that causes large economic losses worldwide, and this is the first original research article to investigate the role of ppGpp in this important species. Here, we revealed the function of RelA and SpoT in ppGpp production, physiology, pathogenicity, and stress resistance in Xcc. Most intriguingly, we found that ppGpp levels and downstream ppGpp-dependent phenotypes were mediated predominantly by SpoT, with RelA having only a supplementary role. Taken together, the results of the current study provide new insight into the role of ppGpp in the biology of Xcc, which could also have important implications for the role of ppGpp in the survival and pathogenicity of other pathogenic bacteria.
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49
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Bessaiah H, Anamalé C, Sung J, Dozois CM. What Flips the Switch? Signals and Stress Regulating Extraintestinal Pathogenic Escherichia coli Type 1 Fimbriae (Pili). Microorganisms 2021; 10:5. [PMID: 35056454 PMCID: PMC8777976 DOI: 10.3390/microorganisms10010005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/18/2022] Open
Abstract
Pathogens are exposed to a multitude of harmful conditions imposed by the environment of the host. Bacterial responses against these stresses are pivotal for successful host colonization and pathogenesis. In the case of many E. coli strains, type 1 fimbriae (pili) are an important colonization factor that can contribute to diseases such as urinary tract infections and neonatal meningitis. Production of type 1 fimbriae in E. coli is dependent on an invertible promoter element, fimS, which serves as a phase variation switch determining whether or not a bacterial cell will produce type 1 fimbriae. In this review, we present aspects of signaling and stress involved in mediating regulation of type 1 fimbriae in extraintestinal E. coli; in particular, how certain regulatory mechanisms, some of which are linked to stress response, can influence production of fimbriae and influence bacterial colonization and infection. We suggest that regulation of type 1 fimbriae is potentially linked to environmental stress responses, providing a perspective for how environmental cues in the host and bacterial stress response during infection both play an important role in regulating extraintestinal pathogenic E. coli colonization and virulence.
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Affiliation(s)
- Hicham Bessaiah
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (H.B.); (C.A.); (J.S.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3G 0B1, Canada
| | - Carole Anamalé
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (H.B.); (C.A.); (J.S.)
| | - Jacqueline Sung
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (H.B.); (C.A.); (J.S.)
- Department of Microbiology and Immunology, McGill University, Montreal, QC H3G 0B1, Canada
| | - Charles M. Dozois
- Institut National de Recherche Scientifique (INRS)-Centre Armand-Frappier Santé Biotechnologie, Laval, QC H7V 1B7, Canada; (H.B.); (C.A.); (J.S.)
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Saint-Hyacinthe, QC J2S 2M2, Canada
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50
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Tan YS, Wang L, Wang YY, He QE, Liu ZH, Zhu Z, Song K, Li BZ, Yuan YJ. Protein acetylation regulates xylose metabolism during adaptation of Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:241. [PMID: 34920742 PMCID: PMC8684234 DOI: 10.1186/s13068-021-02090-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND As the second most abundant polysaccharide in nature, hemicellulose can be degraded to xylose as the feedstock for bioconversion to fuels and chemicals. To enhance xylose conversion, the engineered Saccharomyces cerevisiae with xylose metabolic pathway is usually adapted with xylose as the carbon source in the laboratory. However, the mechanism under the adaptation phenomena of the engineered strain is still unclear. RESULTS In this study, xylose-utilizing S. cerevisiae was constructed and used for the adaptation study. It was found that xylose consumption rate increased 1.24-fold in the second incubation of the yYST12 strain in synthetic complete-xylose medium compared with the first incubation. The study figured out that it was observed at the single-cell level that the stagnation time for xylose utilization was reduced after adaptation with xylose medium in the microfluidic device. Such transient memory of xylose metabolism after adaptation with xylose medium, named "xylose consumption memory", was observed in the strains with both xylose isomerase pathway and xylose reductase and xylitol dehydrogenase pathways. In further, the proteomic acetylation of the strains before and after adaptation was investigated, and it was revealed that H4K5 was one of the most differential acetylation sites related to xylose consumption memory of engineered S. cerevisiae. We tested 8 genes encoding acetylase or deacetylase, and it was found that the knockout of the GCN5 and HPA2 encoding acetylases enhanced the xylose consumption memory. CONCLUSIONS The behavior of xylose consumption memory in engineered S. cerevisiae can be successfully induced with xylose in the adaptation. H4K5Ac and two genes of GCN5 and HPA2 are related to xylose consumption memory of engineered S. cerevisiae during adaptation. This study provides valuable insights into the xylose adaptation of engineered S. cerevisiae.
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Affiliation(s)
- Yong-Shui Tan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Li Wang
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Ying-Ying Wang
- Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096 People’s Republic of China
| | - Qi-En He
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Zhi-Hua Liu
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Zhen Zhu
- Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096 People’s Republic of China
| | - Kai Song
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Bing-Zhi Li
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
| | - Ying-Jin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 People’s Republic of China
- Synthetic Biology Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072 People’s Republic of China
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