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Singh P, Kaur J. MSMEG_5850, a global TetR family member supports Mycobacterium smegmatis to survive environmental stress. Folia Microbiol (Praha) 2024:10.1007/s12223-024-01186-9. [PMID: 39017913 DOI: 10.1007/s12223-024-01186-9] [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: 11/02/2023] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
A Mycobacterium smegmatis transcriptional regulator, MSMEG_5850, and its ortholog in M. tuberculosis, rv0775 were annotated as putative TetR Family Transcriptional Regulators. Our previous study revealed MSMEG_5850 is involved in global transcriptional regulation in M. smegmatis and the presence of gene product supported the survival of bacteria during nutritional starvation. Phylogenetic analysis showed that MSMEG_5850 diverged early in comparison to its counterparts in virulent strains. Therefore, the expression pattern of MSMEG_5850 and its counterpart, rv0775, was compared during various in-vitro growth and stress conditions. Expression of MSMEG_5850 was induced under different environmental stresses while no change in expression was observed under mid-exponential and stationary phases. No expression of rv0775 was observed under any stress condition tested, while the gene was expressed during the mid-exponential phase that declined in the stationary phase. The effect of MSMEG_5850 on the survival of M. smegmatis under stress conditions and growth pattern was studied using wild type, knockout, and supplemented strain. Deletion of MSMEG_5850 resulted in altered colony morphology, biofilm/pellicle formation, and growth pattern of M. smegmatis. The survival rate of wild-type MSMEG_5850 was higher in comparison to knockout under different environmental stresses. Overall, this study suggested the role of MSMEG_5850 in the growth and adaptation/survival of M. smegmatis under stress conditions.
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Affiliation(s)
- Parul Singh
- Department of Biotechnology, Panjab University, BMS Block-1, Sector-25, Chandigarh, India, 160014
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, BMS Block-1, Sector-25, Chandigarh, India, 160014.
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2
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Ascensao JA, Denk J, Lok K, Yu Q, Wetmore KM, Hallatschek O. Rediversification following ecotype isolation reveals hidden adaptive potential. Curr Biol 2024; 34:855-867.e6. [PMID: 38325377 PMCID: PMC10911448 DOI: 10.1016/j.cub.2024.01.029] [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: 05/10/2023] [Revised: 11/09/2023] [Accepted: 01/10/2024] [Indexed: 02/09/2024]
Abstract
Microbial communities play a critical role in ecological processes, and their diversity is key to their functioning. However, little is known about whether communities can regenerate ecological diversity following ecotype removal or extinction and how the rediversified communities would compare to the original ones. Here, we show that simple two-ecotype communities from the E. coli long-term evolution experiment (LTEE) consistently rediversified into two ecotypes following the isolation of one of the ecotypes, coexisting via negative frequency-dependent selection. Communities separated by more than 30,000 generations of evolutionary time rediversify in similar ways. The rediversified ecotype appears to share a number of growth traits with the ecotype it replaces. However, the rediversified community is also different from the original community in ways relevant to the mechanism of ecotype coexistence-for example, in stationary phase response and survival. We found substantial variation in the transcriptional states between the two original ecotypes, whereas the differences within the rediversified community were comparatively smaller, although the rediversified community showed unique patterns of differential expression. Our results suggest that evolution may leave room for alternative diversification processes even in a maximally reduced community of only two strains. We hypothesize that the presence of alternative evolutionary pathways may be even more pronounced in communities of many species where there are even more potential niches, highlighting an important role for perturbations, such as species removal, in evolving ecological communities.
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Affiliation(s)
- Joao A Ascensao
- Department of Bioengineering, University of California Berkeley, Berkeley, CA, USA
| | - Jonas Denk
- Department of Physics, University of California Berkeley Berkeley, CA, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
| | - Kristen Lok
- Department of Bioengineering, University of California Berkeley, Berkeley, CA, USA
- Present affiliation: Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - QinQin Yu
- Department of Physics, University of California Berkeley Berkeley, CA, USA
- Present affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States
| | - Kelly M Wetmore
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Oskar Hallatschek
- Department of Physics, University of California Berkeley Berkeley, CA, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA, USA
- Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany
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3
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Graham CI, MacMartin TL, de Kievit TR, Brassinga AKC. Molecular regulation of virulence in Legionella pneumophila. Mol Microbiol 2024; 121:167-195. [PMID: 37908155 DOI: 10.1111/mmi.15172] [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: 05/31/2023] [Revised: 09/15/2023] [Accepted: 09/17/2023] [Indexed: 11/02/2023]
Abstract
Legionella pneumophila is a gram-negative bacteria found in natural and anthropogenic aquatic environments such as evaporative cooling towers, where it reproduces as an intracellular parasite of cohabiting protozoa. If L. pneumophila is aerosolized and inhaled by a susceptible person, bacteria may colonize their alveolar macrophages causing the opportunistic pneumonia Legionnaires' disease. L. pneumophila utilizes an elaborate regulatory network to control virulence processes such as the Dot/Icm Type IV secretion system and effector repertoire, responding to changing nutritional cues as their host becomes depleted. The bacteria subsequently differentiate to a transmissive state that can survive in the environment until a replacement host is encountered and colonized. In this review, we discuss the lifecycle of L. pneumophila and the molecular regulatory network that senses nutritional depletion via the stringent response, a link to stationary phase-like metabolic changes via alternative sigma factors, and two-component systems that are homologous to stress sensors in other pathogens, to regulate differentiation between the intracellular replicative phase and more transmissible states. Together, we highlight how this prototypic intracellular pathogen offers enormous potential in understanding how molecular mechanisms enable intracellular parasitism and pathogenicity.
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Affiliation(s)
- Christopher I Graham
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teassa L MacMartin
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teresa R de Kievit
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ann Karen C Brassinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
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4
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Chai G, Li J, Li Z. The interactive effects of ocean acidification and warming on bioeroding sponge Spheciospongia vesparium microbiome indicated by metatranscriptomics. Microbiol Res 2024; 278:127542. [PMID: 37979302 DOI: 10.1016/j.micres.2023.127542] [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: 08/03/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/20/2023]
Abstract
Global climate change will cause coral reefs decline and is expected to increase the reef erosion potential of bioeroding sponges. Microbial symbionts are essential for the overall fitness and survival of sponge holobionts in changing ocean environments. However, we rarely know about the impacts of ocean warming and acidification on bioeroding sponge microbiome. Here, the structural and functional changes of the bioeroding sponge Spheciospongia vesparium microbiome, as well as its recovery potential, were investigated at the RNA level in a laboratory system simulating 32 °C and pH 7.7. Based on metatranscriptome analysis, acidification showed no significant impact, while warming or simultaneous warming and acidification disrupted the sponge microbiome. Warming caused microbial dysbiosis and recruited potentially opportunistic and pathogenic members of Nesiotobacter, Oceanospirillaceae, Deltaproteobacteria, Epsilonproteobacteria, Bacteroidetes and Firmicutes. Moreover, warming disrupted nutrient exchange and molecular interactions in the sponge holobiont, accompanied by stimulation of virulence activity and anaerobic metabolism including denitrification and dissimilatory reduction of nitrate and sulfate to promote sponge necrosis. Particularly, the interaction between acidification and warming alleviated the negative effects of warming and enhanced the Rhodobacteraceae-driven ethylmalonyl-CoA pathway and sulfur-oxidizing multienzyme system. The microbiome could not recover during the experiment period after warming or combined stress was removed. This study suggests that warming or combined warming and acidification will irreversibly destabilize the S. vesparium microbial community structure and function, and provides insight into the molecular mechanisms of the interactive effects of acidification and warming on the sponge microbiome.
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Affiliation(s)
- Guangjun Chai
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jinlong Li
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhiyong Li
- Marine Biotechnology Laboratory, State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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5
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Jeong GJ, Khan F, Tabassum N, Kim YM. Cellular and physiological roles of sigma factors in Vibrio spp.: A comprehensive review. Int J Biol Macromol 2024; 254:127833. [PMID: 37918595 DOI: 10.1016/j.ijbiomac.2023.127833] [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: 08/23/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Vibrio species are motile gram-negative bacteria commonly found in aquatic environments. Vibrio species include pathogenic as well as non-pathogenic strains. Pathogenic Vibrio species have been reported in invertebrates and humans, whereas non-pathogenic strains are involved in symbiotic relationships with their eukaryotic hosts. These bacteria are also able to adapt to fluctuations in temperature, salinity, and pH, in addition to oxidative stress, and osmotic pressure in aquatic ecosystems. Moreover, they have also developed protective mechanisms against the immune systems of their hosts. Vibrio species accomplish adaptation to changing environments outside or inside the host by altering their gene expression profiles. To this end, several sigma factors specifically regulate gene expression, particularly under stressful environmental conditions. Moreover, other sigma factors are associated with biofilm formation and virulence as well. This review discusses different types of sigma and anti-sigma factors of Vibrio species involved in virulence and regulation of gene expression upon changes in environmental conditions. The evolutionary relationships between sigma factors with various physiological roles in Vibrio species are also discussed extensively.
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Affiliation(s)
- Geum-Jae Jeong
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Fazlurrahman Khan
- Institute of Fisheries Sciences, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan 48513, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
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6
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Sánchez-Jiménez A, Llamas MA, Marcos-Torres FJ. Transcriptional Regulators Controlling Virulence in Pseudomonas aeruginosa. Int J Mol Sci 2023; 24:11895. [PMID: 37569271 PMCID: PMC10418997 DOI: 10.3390/ijms241511895] [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: 07/04/2023] [Revised: 07/21/2023] [Accepted: 07/22/2023] [Indexed: 08/13/2023] Open
Abstract
Pseudomonas aeruginosa is a pathogen capable of colonizing virtually every human tissue. The host colonization competence and versatility of this pathogen are powered by a wide array of virulence factors necessary in different steps of the infection process. This includes factors involved in bacterial motility and attachment, biofilm formation, the production and secretion of extracellular invasive enzymes and exotoxins, the production of toxic secondary metabolites, and the acquisition of iron. Expression of these virulence factors during infection is tightly regulated, which allows their production only when they are needed. This process optimizes host colonization and virulence. In this work, we review the intricate network of transcriptional regulators that control the expression of virulence factors in P. aeruginosa, including one- and two-component systems and σ factors. Because inhibition of virulence holds promise as a target for new antimicrobials, blocking the regulators that trigger the production of virulence determinants in P. aeruginosa is a promising strategy to fight this clinically relevant pathogen.
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Affiliation(s)
| | - María A. Llamas
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
| | - Francisco Javier Marcos-Torres
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, 18008 Granada, Spain;
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7
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Rey-Varela D, Balado M, Lemos ML. The Sigma Factor AsbI Is Required for the Expression of Acinetobactin Siderophore Transport Genes in Aeromonas salmonicida. Int J Mol Sci 2023; 24:ijms24119672. [PMID: 37298622 DOI: 10.3390/ijms24119672] [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: 04/28/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Aeromonas salmonicida subsp. salmonicida (A. salmonicida), a Gram-negative bacterium causing furunculosis in fish, produces the siderophores acinetobactin and amonabactins in order to extract iron from its hosts. While the synthesis and transport of both systems is well understood, the regulation pathways and conditions necessary for the production of each one of these siderophores are not clear. The acinetobactin gene cluster carries a gene (asbI) encoding a putative sigma factor belonging to group 4 σ factors, or, the ExtraCytoplasmic Function (ECF) group. By generating a null asbI mutant, we demonstrate that AsbI is a key regulator that controls acinetobactin acquisition in A. salmonicida, since it directly regulates the expression of the outer membrane transporter gene and other genes necessary for Fe-acinetobactin transport. Furthermore, AsbI regulatory functions are interconnected with other iron-dependent regulators, such as the Fur protein, as well as with other sigma factors in a complex regulatory network.
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Affiliation(s)
- Diego Rey-Varela
- Departmento de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Miguel Balado
- Departmento de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel L Lemos
- Departmento de Microbiología y Parasitología, Instituto de Acuicultura, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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8
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Murashko ON, Yeh KH, Yu CHA, Kaberdin VR, Lin-Chao S. Sodium Fluoride Exposure Leads to ATP Depletion and Altered RNA Decay in Escherichia coli under Anaerobic Conditions. Microbiol Spectr 2023; 11:e0415822. [PMID: 36939343 PMCID: PMC10100675 DOI: 10.1128/spectrum.04158-22] [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: 10/16/2022] [Accepted: 02/11/2023] [Indexed: 03/21/2023] Open
Abstract
Although fluoride-containing compounds are widely used to inhibit bacterial growth, the reprogramming of gene expression underlying cellular responses to fluoride, especially under anaerobic conditions, is still poorly understood. Here, we compare the genome-wide transcriptomic profiles of E. coli grown in the absence (control) or presence (20 and 70 mM) of sodium fluoride (NaF) under anaerobic conditions and assess the impact of fluoride-dependent ATP depletion on RNA turnover. Tiling array analysis revealed transcripts displaying altered abundance in response to NaF treatments. Quantile-based K-means clustering uncovered a subset of genes that were highly upregulated and then downregulated in response to increased and subsequently decreased fluoride concentrations, many of which (~40%) contained repetitive extragenic palindromic (REP) sequences. Northern blot analysis of some of these highly upregulated REP-containing transcripts (i.e., osmC, proP, efeO and yghA) confirmed their considerably enhanced abundance in response to NaF treatment. An mRNA stability analysis of osmC and yghA transcripts demonstrated that fluoride treatment slows down RNA degradation, thereby enhancing RNA stability and steady-state mRNA levels. Moreover, we demonstrate that turnover of these transcripts depends on RNase E activity and RNA degradosome. Thus, we show that NaF exerts significant effects at the whole-transcriptome level under hypoxic growth (i.e., mimicking the host environment), and fluoride can impact gene expression posttranscriptionally by slowing down ATP-dependent degradation of structured RNAs. IMPORTANCE Gram-negative Escherichia coli is a rod-shaped facultative anaerobic bacterium commonly found in microaerobic/anaerobic environments, including the dental plaques of warm-blooded organisms. These latter can be treated efficiently with fluoride-rich compounds that act as anticaries agents to prevent tooth decay. Although fluoride inhibits microbial growth by affecting metabolic pathways, the molecular mechanisms underlying its activity under anaerobic conditions remain poorly defined. Here, using genome-wide transcriptomics, we explore the impact of fluoride treatments on E. coli gene expression under anaerobic conditions. We reveal key gene clusters associated with cellular responses to fluoride and define its ATP-dependent stabilizing effects on transcripts containing repetitive extragenic palindromic sequences. We demonstrate the mechanisms controlling the RNA stability of these REP-containing mRNAs. Thus, fluoride can affect gene expression posttranscriptionally by stabilizing structured RNAs.
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Affiliation(s)
| | - Kun-Hai Yeh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | - Vladimir R. Kaberdin
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country UPV/EHU, Leioa, Spain
- Basque Foundation for Science, IKERBASQUE, Bilbao, Spain
- Research Centre for Experimental Marine Biology and Biotechnology (PIE-UPV/EHU), Plentzia, Spain
| | - Sue Lin-Chao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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9
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Neira JL, Palomino-Schätzlein M. Folding of the nascent polypeptide chain of a histidine phosphocarrier protein in vitro. Arch Biochem Biophys 2023; 736:109538. [PMID: 36738980 DOI: 10.1016/j.abb.2023.109538] [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: 12/19/2022] [Revised: 01/28/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
The phosphotransferase system (PTS), a metabolic pathway formed by five proteins, modulates the use of sugars in bacteria. The second protein in the chain is the histidine phosphocarrier, HPr, with the binding site at His15. The HPr kinase/phosphorylase (HPrK/P), involved in the bacterial use of carbon sources, phosphorylates HPr at Ser46, and it binds at its binding site. The regulator of sigma D protein (Rsd) also binds to HPr at His15. We have designed fragments of HPr, growing from its N-terminus and containing the His15. In this work, we obtained three fragments, HPr38, HPr58 and HPr70, comprising the first thirty-eight, fifty-eight and seventy residues of HPr, respectively. All fragments were mainly disordered, with evidence of a weak native-like, helical population around the binding site, as shown by fluorescence, far-ultraviolet circular dichroism, size exclusion chromatography and nuclear magnetic resonance. Although HPr38, HPr58 and HPr70 were disordered, they could bind to: (i) the N-terminal domain of first protein of the PTS, EIN; (ii) Rsd; and, (iii) HPrK/P, as shown by fluorescence and biolayer interferometry (BLI). The association constants for each protein to any of the fragments were in the low micromolar range, within the same range than those measured in the binding of HPr to each protein. Then, although acquisition of stable, native-like secondary and tertiary structures occurred at the last residues of the polypeptide, the ability to bind protein partners happened much earlier in the growing chain. Binding was related to the presence of the native-like structure around His15.
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Affiliation(s)
- José L Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Joint Units IQFR-CSIC-BIFI and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50018, Zaragoza, Spain.
| | - Martina Palomino-Schätzlein
- ProtoQSAR SL, CEEI-Valencia, Parque Tecnológico de Valencia, Av. Benjamin Franklin 12 (Dep. 8), 46980, Paterna, Valencia, Spain
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10
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Metal-Responsive Transcription Factors Co-Regulate Anti-Sigma Factor (Rsd) and Ribosome Dimerization Factor Expression. Int J Mol Sci 2023; 24:ijms24054717. [PMID: 36902154 PMCID: PMC10003395 DOI: 10.3390/ijms24054717] [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: 12/27/2022] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 03/05/2023] Open
Abstract
Bacteria exposed to stress survive by regulating the expression of several genes at the transcriptional and translational levels. For instance, in Escherichia coli, when growth is arrested in response to stress, such as nutrient starvation, the anti-sigma factor Rsd is expressed to inactivate the global regulator RpoD and activate the sigma factor RpoS. However, ribosome modulation factor (RMF) expressed in response to growth arrest binds to 70S ribosomes to form inactive 100S ribosomes and inhibit translational activity. Moreover, stress due to fluctuations in the concentration of metal ions essential for various intracellular pathways is regulated by a homeostatic mechanism involving metal-responsive transcription factors (TFs). Therefore, in this study, we examined the binding of a few metal-responsive TFs to the promoter regions of rsd and rmf through promoter-specific TF screening and studied the effects of these TFs on the expression of rsd and rmf in each TF gene-deficient E. coli strain through quantitative PCR, Western blot imaging, and 100S ribosome formation analysis. Our results suggest that several metal-responsive TFs (CueR, Fur, KdpE, MntR, NhaR, PhoP, ZntR, and ZraR) and metal ions (Cu2+, Fe2+, K+, Mn2+, Na+, Mg2+, and Zn2+) influence rsd and rmf gene expression while regulating transcriptional and translational activities.
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11
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Fu X, Xie DF, Zhou YY, Cheng RY, Zhang XY, Zhou SD, He XJ. Phylogeny and adaptive evolution of subgenus Rhizirideum (Amaryllidaceae, Allium) based on plastid genomes. BMC PLANT BIOLOGY 2023; 23:70. [PMID: 36726056 PMCID: PMC9890777 DOI: 10.1186/s12870-022-03993-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 12/09/2022] [Indexed: 06/01/2023]
Abstract
The subgenus Rhizirideum in the genus Allium consists of 38 species worldwide and forms five sections (A. sect. Rhizomatosa, A. sect. Tenuissima, A. sect. Rhizirideum, A. sect. Eduardia, and A. sect. Caespitosoprason), A. sect. Caespitosoprason being merged into A. sect. Rhizomatosa recently. Previous studies on this subgenus mainly focused on separate sections. To investigate the inter-section and inter-subgenera phylogenetic relationships and adaptive evolution of A. subg. Rhizirideum, we selected thirteen representative species, which cover five sections of this subgenus and can represent four typical phenotypes of it. We conducted the comparative plastome analysis with our thirteen plastomes. And phylogenetic inferences with CDSs and complete sequences of plastomes of our thirteen species and another fifty-four related species were also performed. As a result, the A. subg. Rhizirideum plastomes were relatively conservative in structure, IR/SC borders, codon usage, and repeat sequence. In phylogenetic results, the inter-subgenera relationships among A. subg. Rhizirideum and other genus Allium subgenera were generally similar to the previous reports. In contrast, the inter-section relationships within our subgenus A. subg. Rhizirideum were newly resolved in this study. A. sect. Rhizomatosa and A. sect. Tenuissima were sister branches, which were then clustered with A. sect. Rhizirideum and A. sect. Eduardia successively. However, Allium Polyrhizum Turcz. ex Regel, type species of A. sect. Caespitosoprason, was resolved as the basal taxon of A. subg. Rhizirideum. Allium siphonanthum J. M. Xu was also found in clade A. subg. Cyathophora instead of clade A. subg. Rhizirideum. The selective pressure analysis was also conducted, and most protein-coding genes were under purifying selection. At the same time, just one gene, ycf2, was found under positive selection, and another three genes (rbcL, ycf1a, ycf1b) presented relaxed selection, which were all involved in the photosynthesis. The low temperature, dry climate, and high altitude of the extreme habitats where A. subg. Rhizirideum species grow might impose intense natural selection forces on their plastome genes for photosynthesis. In summary, our research provides new insights into the phylogeny and adaptive evolution of A. subg. Rhizirideum. Moreover, we suggest that the positions of the A. subg. Rhizirideum species A. polyrhizum and A. siphonanthum should be reconsidered.
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Affiliation(s)
- Xiao Fu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Deng-Feng Xie
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Yu-Yang Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Rui-Yu Cheng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Xiang-Yi Zhang
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Song-Dong Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China
| | - Xing-Jin He
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, 610065, Chengdu, Sichuan, The People's Republic of China.
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12
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Qin HH, Cai J, Liu CK, Zhou RX, Price M, Zhou SD, He XJ. The plastid genome of twenty-two species from Ferula, Talassia, and Soranthus: comparative analysis, phylogenetic implications, and adaptive evolution. BMC PLANT BIOLOGY 2023; 23:9. [PMID: 36604614 PMCID: PMC9814190 DOI: 10.1186/s12870-022-04027-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND The Ferula genus encompasses 180-185 species and is one of the largest genera in Apiaceae, with many of Ferula species possessing important medical value. The previous studies provided more information for Ferula, but its infrageneric relationships are still confusing. In addition, its genetic basis of its adaptive evolution remains poorly understood. Plastid genomes with more variable sites have the potential to reconstruct robust phylogeny in plants and investigate the adaptive evolution of plants. Although chloroplast genomes have been reported within the Ferula genus, few studies have been conducted using chloroplast genomes, especially for endemic species in China. RESULTS Comprehensively comparative analyses of 22 newly sequenced and assembled plastomes indicated that these plastomes had highly conserved genome structure, gene number, codon usage, and repeats type and distribution, but varied in plastomes size, GC content, and the SC/IR boundaries. Thirteen mutation hotspot regions were detected and they would serve as the promising DNA barcodes candidates for species identification in Ferula and related genera. Phylogenomic analyses with high supports and resolutions showed that Talassia transiliensis and Soranthus meyeri were nested in the Ferula genus, and thus they should be transferred into the Ferula genus. Our phylogenies also indicated the monophyly of subgenera Sinoferula and subgenera Narthex in Ferula genus. Twelve genes with significant posterior probabilities for codon sites were identified in the positively selective analysis, and their function may relate to the photosystem II, ATP subunit, and NADH dehydrogenase. Most of them might play an important role to help Ferula species adapt to high-temperatures, strong-light, and drought habitats. CONCLUSION Plastome data is powerful and efficient to improve the support and resolution of the complicated Ferula phylogeny. Twelve genes with significant posterior probabilities for codon sites were helpful for Ferula to adapt to the harsh environment. Overall, our study supplies a new perspective for comprehending the phylogeny and evolution of Ferula.
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Affiliation(s)
- Huan-Huan Qin
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Jing Cai
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Chang-Kun Liu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Ren-Xiu Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Megan Price
- Key Laboratory of Conservation Biology On Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Song-Dong Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
| | - Xing-Jin He
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
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Chen L, Zhang M, Li X, Wu Q, Xue X, Zhang T, Lu R, Zhang Y. AphA directly activates the transcription of polysaccharide biosynthesis gene scvE in Vibrio parahaemolyticus. Gene 2023; 851:146980. [DOI: 10.1016/j.gene.2022.146980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022]
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14
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Ferrarini MG, Dell’Aglio E, Vallier A, Balmand S, Vincent-Monégat C, Hughes S, Gillet B, Parisot N, Zaidman-Rémy A, Vieira C, Heddi A, Rebollo R. Efficient compartmentalization in insect bacteriomes protects symbiotic bacteria from host immune system. MICROBIOME 2022; 10:156. [PMID: 36163269 PMCID: PMC9513942 DOI: 10.1186/s40168-022-01334-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/25/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Many insects house symbiotic intracellular bacteria (endosymbionts) that provide them with essential nutrients, thus promoting the usage of nutrient-poor habitats. Endosymbiont seclusion within host specialized cells, called bacteriocytes, often organized in a dedicated organ, the bacteriome, is crucial in protecting them from host immune defenses while avoiding chronic host immune activation. Previous evidence obtained in the cereal weevil Sitophilus oryzae has shown that bacteriome immunity is activated against invading pathogens, suggesting endosymbionts might be targeted and impacted by immune effectors during an immune challenge. To pinpoint any molecular determinants associated with such challenges, we conducted a dual transcriptomic analysis of S. oryzae's bacteriome subjected to immunogenic peptidoglycan fragments. RESULTS We show that upon immune challenge, the bacteriome actively participates in the innate immune response via induction of antimicrobial peptides (AMPs). Surprisingly, endosymbionts do not undergo any transcriptomic changes, indicating that this potential threat goes unnoticed. Immunohistochemistry showed that TCT-induced AMPs are located outside the bacteriome, excluding direct contact with the endosymbionts. CONCLUSIONS This work demonstrates that endosymbiont protection during an immune challenge is mainly achieved by efficient confinement within bacteriomes, which provides physical separation between host systemic response and endosymbionts. Video Abstract.
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Affiliation(s)
- Mariana Galvão Ferrarini
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - Elisa Dell’Aglio
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Agnès Vallier
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Séverine Balmand
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
| | | | - Sandrine Hughes
- UMR5242, Institut de Génomique Fonctionnelle de Lyon (IGFL), Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon (Univ Lyon), F-69007 Lyon, France
| | - Benjamin Gillet
- UMR5242, Institut de Génomique Fonctionnelle de Lyon (IGFL), Ecole Normale Supérieure de Lyon, Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon (Univ Lyon), F-69007 Lyon, France
| | - Nicolas Parisot
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Anna Zaidman-Rémy
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Cristina Vieira
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Université Lyon 1, Université Lyon, Villeurbanne, France
| | - Abdelaziz Heddi
- Univ Lyon, INSA-Lyon, INRAE, BF2I, UMR 203, 69621 Villeurbanne, France
| | - Rita Rebollo
- Univ Lyon, INRAE, INSA-Lyon, BF2I, UMR 203, 69621 Villeurbanne, France
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15
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Cai X, Li X, Qin J, Zhang Y, Yan B, Cai J. Gene rppA co-regulated by LRR, SigA, and CcpA mediates antibiotic resistance in Bacillus thuringiensis. Appl Microbiol Biotechnol 2022; 106:5687-5699. [PMID: 35906441 DOI: 10.1007/s00253-022-12090-y] [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: 06/25/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 11/26/2022]
Abstract
Antibiotic resistance genes are usually tightly controlled by transcription factors and RNA regulatory elements including sRNAs, riboswitches, and attenuators, and their expression is activated to respond to antibiotic exposure. In previous work, we revealed that the rppA gene is regulated by attenuator LRR and two mistranslation products in Bacillus thuringiensis BMB171. However, its function and promoter regulation is still not precise. In this study, we demonstrated that the encoding product of the rppA gene acts as an ARE1 ABC-F protein and confers resistance to antibiotics virginiamycin M1 and lincomycin when overexpressed. Besides the reported attenuator LRR, the expression of the rppA gene is controlled by the sigma factor SigA and a global transcription factor CcpA. Consequently, its promoter activity is mainly maintained at the stationary phase of cell growth and inhibited in the presence of glucose. Our study revealed the function and regulation of the rppA gene in detail. KEY POINTS: • The RppA protein acts as an ARE1 ABC-F protein • The rppA gene confers resistance to antibiotics virginiamycin M1 and lincomycin when overexpressed • The expression of the rppA gene is regulated by the sigma factor SigA and the pleiotropic regulator CcpA.
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Affiliation(s)
- Xia Cai
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xuelian Li
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jiaxin Qin
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Yizhuo Zhang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Bing Yan
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jun Cai
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, China.
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin, 300071, China.
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16
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Baptista ISC, Kandavalli V, Chauhan V, Bahrudeen MNM, Almeida BLB, Palma CSD, Dash S, Ribeiro AS. Sequence-dependent model of genes with dual σ factor preference. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194812. [PMID: 35338024 DOI: 10.1016/j.bbagrm.2022.194812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/08/2022] [Accepted: 03/16/2022] [Indexed: 10/18/2022]
Abstract
Escherichia coli uses σ factors to quickly control large gene cohorts during stress conditions. While most of its genes respond to a single σ factor, approximately 5% of them have dual σ factor preference. The most common are those responsive to both σ70, which controls housekeeping genes, and σ38, which activates genes during stationary growth and stresses. Using RNA-seq and flow-cytometry measurements, we show that 'σ70+38 genes' are nearly as upregulated in stationary growth as 'σ38 genes'. Moreover, we find a clear quantitative relationship between their promoter sequence and their response strength to changes in σ38 levels. We then propose and validate a sequence dependent model of σ70+38 genes, with dual sensitivity to σ38 and σ70, that is applicable in the exponential and stationary growth phases, as well in the transient period in between. We further propose a general model, applicable to other stresses and σ factor combinations. Given this, promoters controlling σ70+38 genes (and variants) could become important building blocks of synthetic circuits with predictable, sequence-dependent sensitivity to transitions between the exponential and stationary growth phases.
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Affiliation(s)
- Ines S C Baptista
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Vinodh Kandavalli
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland; Department of Cell and Molecular Biology, Uppsala University, Uppsala 752 37, Sweden
| | - Vatsala Chauhan
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Mohamed N M Bahrudeen
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Bilena L B Almeida
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Cristina S D Palma
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Suchintak Dash
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland
| | - Andre S Ribeiro
- Laboratory of Biosystem Dynamics, Faculty of Medicine and Health Technology, Tampere University, Tampere 33520, Finland; Center of Technology and Systems (CTS-Uninova), NOVA University of Lisbon, 2829-516 Monte de Caparica, Portugal.
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17
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A Role for the RNA Polymerase Gene Specificity Factor σ 54 in the Uniform Colony Growth of Uropathogenic Escherichia coli. J Bacteriol 2022; 204:e0003122. [PMID: 35357162 PMCID: PMC9017345 DOI: 10.1128/jb.00031-22] [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] [Indexed: 11/20/2022] Open
Abstract
The canonical function of a bacterial sigma (σ) factor is to determine the gene specificity of the RNA polymerase (RNAP). In several diverse bacterial species, the σ54 factor uniquely confers distinct functional and regulatory properties on the RNAP. A hallmark feature of the σ54-RNAP is the obligatory requirement for an activator ATPase to allow transcription initiation. Different activator ATPases couple diverse environmental cues to the σ54-RNAP to mediate adaptive changes in gene expression. Hence, the genes that rely upon σ54 for their transcription have a wide range of different functions suggesting that the repertoire of functions performed by genes, directly or indirectly affected by σ54, is not yet exhaustive. By comparing the growth patterns of prototypical enteropathogenic, uropathogenic, and nonpathogenic Escherichia coli strains devoid of σ54, we uncovered that the absence of σ54 results in two differently sized colonies that appear at different times specifically in the uropathogenic E. coli (UPEC) strain. Notably, UPEC bacteria devoid of individual activator ATPases of the σ54-RNAP do not phenocopy the σ54 mutant strain. Thus, it seems that σ54’s role as a determinant of uniform colony appearance in UPEC bacteria represents a putative non-canonical function of σ54 in regulating genetic information flow. IMPORTANCE RNA synthesis is the first step of gene expression. The multisubunit RNA polymerase (RNAP) is the central enzyme responsible for RNA synthesis in bacteria. The dissociable sigma (σ) factor subunit directs the RNAP to different sets of genes to allow their expression in response to various cellular needs. Of the seven σ factors in Escherichia coli and related bacteria, σ54 exists in a class of its own. This study has uncovered that σ54 is a determinant of the uniform growth of uropathogenic E. coli on solid media. This finding suggests a role for this σ54 in gene regulation that extends beyond its known function as an RNAP gene specificity factor.
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18
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Liu X, Zhao G, Sun S, Fan C, Feng X, Xiong P. Biosynthetic Pathway and Metabolic Engineering of Succinic Acid. Front Bioeng Biotechnol 2022; 10:843887. [PMID: 35350186 PMCID: PMC8957974 DOI: 10.3389/fbioe.2022.843887] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/16/2022] [Indexed: 11/25/2022] Open
Abstract
Succinic acid, a dicarboxylic acid produced as an intermediate of the tricarboxylic acid (TCA) cycle, is one of the most important platform chemicals for the production of various high value-added derivatives. As traditional chemical synthesis processes suffer from nonrenewable resources and environment pollution, succinic acid biosynthesis has drawn increasing attention as a viable, more environmentally friendly alternative. To date, several metabolic engineering approaches have been utilized for constructing and optimizing succinic acid cell factories. In this review, different succinic acid biosynthesis pathways are summarized, with a focus on the key enzymes and metabolic engineering approaches, which mainly include redirecting carbon flux, balancing NADH/NAD+ ratios, and optimizing CO2 supplementation. Finally, future perspectives on the microbial production of succinic acid are discussed.
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Affiliation(s)
- Xiutao Liu
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Guang Zhao
- State Key Lab of Microbial Technology, Shandong University, Qingdao, China
| | - Shengjie Sun
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Chuanle Fan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xinjun Feng
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Peng Xiong
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
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19
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Iron Homeostasis in Pseudomonas aeruginosa: Targeting Iron Acquisition and Storage as an Antimicrobial Strategy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:29-68. [DOI: 10.1007/978-3-031-08491-1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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20
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Shimada T, Furuhata S, Ishihama A. Whole set of constitutive promoters for RpoN sigma factor and the regulatory role of its enhancer protein NtrC in Escherichia coli K-12. Microb Genom 2021; 7. [PMID: 34787538 PMCID: PMC8743547 DOI: 10.1099/mgen.0.000653] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The promoter selectivity of Escherichia coli RNA polymerase (RNAP) is determined by its promoter-recognition sigma subunit. The model prokaryote E. coli K-12 contains seven species of the sigma subunit, each recognizing a specific set of promoters. Using genomic SELEX (gSELEX) screening in vitro, we identified the whole set of ‘constitutive’ promoters recognized by the reconstituted RNAP holoenzyme alone, containing RpoD (σ70), RpoS (σ38), RpoH (σ32), RpoF (σ28) or RpoE (σ24), in the absence of other supporting regulatory factors. In contrast, RpoN sigma (σ54), involved in expression of nitrogen-related genes and also other cellular functions, requires an enhancer (or activator) protein, such as NtrC, for transcription initiation. In this study, a series of gSELEX screenings were performed to search for promoters recognized by the RpoN RNAP holoenzyme in the presence and absence of the major nitrogen response enhancer NtrC, the best-characterized enhancer. Based on the RpoN holoenzyme-binding sites, a total of 44 to 61 putative promoters were identified, which were recognized by the RpoN holoenzyme alone. In the presence of the enhancer NtrC, the recognition target increased to 61–81 promoters. Consensus sequences of promoters recognized by RpoN holoenzyme in the absence and presence of NtrC were determined. The promoter activity of a set of NtrC-dependent and -independent RpoN promoters was verified in vivo under nitrogen starvation, in the presence and absence of RpoN and/or NtrC. The promoter activity of some RpoN-recognized promoters increased in the absence of RpoN or NtrC, supporting the concept that the promoter-bound NtrC-enhanced RpoN holoenzyme functions as a repressor against RpoD holoenzyme. Based on our findings, we propose a model in which the RpoN holoenzyme fulfils the dual role of repressor and transcriptase for the same set of genes. We also propose that the promoter recognized by RpoN holoenzyme in the absence of enhancers is the ‘repressive’ promoter. The presence of high-level RpoN sigma in growing E. coli K-12 in rich medium may be related to the repression role of a set of genes needed for the utilization of ammonia as a nitrogen source in poor media. The list of newly identified regulatory targets of RpoN provides insight into E. coli survival under nitrogen-depleted conditions in nature.
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Affiliation(s)
- Tomohiro Shimada
- School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Shun Furuhata
- School of Agriculture, Meiji University, Kawasaki, Kanagawa, Japan
| | - Akira Ishihama
- Micro-Nanotechnology Research Center, Hosei University, Koganei, Tokyo, Japan
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21
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Chen XJ, Wang B, Thompson IP, Huang WE. Rational Design and Characterization of Nitric Oxide Biosensors in E. coli Nissle 1917 and Mini SimCells. ACS Synth Biol 2021; 10:2566-2578. [PMID: 34551261 DOI: 10.1021/acssynbio.1c00223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) is an important disease biomarker found in many chronic inflammatory diseases and cancers. A well-characterized nitric sensing system is useful to aid the rapid development of bacteria therapy and synthetic biology. In this work, we engineered a set of NO-responsive biosensors based on the PnorV promoter and its NorR regulator in the norRVW operon; the circuits were characterized and optimized in probiotic Escherichia coli Nissle 1917 and mini SimCells (minicells containing designed gene circuits for specific tasks). Interestingly, the expression level of NorR displayed an inverse correlation to the PnorV promoter activation, as a strong expression of the NorR regulator resulted in a low amplitude of NO-inducible gene expression. This could be explained by a competitive binding mechanism where the activated and inactivated NorR competitively bind to the same site on the PnorV promoter. To overcome such issues, the NO induction performance was further improved by making a positive feedback loop that fine-tuned the level of NorR. In addition, by examining two integration host factor (IHF) binding sites of the PnorV promoter, we demonstrated that the deletion of the second IHF site increased the maximum signal output by 25% (500 μM DETA/NO) with no notable increase in the basal expression level. The optimized NO-sensing gene circuit in anucleate mini SimCells exhibited increased robustness against external fluctuation in medium composition. The NO detection limit of the optimized gene circuit pPnorVβ was also improved from 25.6 to 1.3 nM in mini SimCells. Moreover, lyophilized mini SimCells can maintain function for over 2 months. Hence, SimCell-based NO biosensors could be used as safe sensor chassis for synthetic biology.
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Affiliation(s)
- Xiaoyu J. Chen
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, United Kingdom
| | - Baojun Wang
- Hangzhou Innovation Center and College of Chemical & Biological Engineering, Zhejiang University, Hangzhou 311200, China
- School of Biological Sciences, University of Edinburgh, G20 Roger Land Building, The Kingʼs Buildings, Edinburgh EH9 3FF, United Kingdom
- ZJU-UoE Joint Research Centre for Engineering Biology, Zhejiang University, Haining 314400, China
| | - Ian P. Thompson
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, United Kingdom
| | - Wei E. Huang
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, United Kingdom
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22
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Residual Helicity at the Active Site of the Histidine Phosphocarrier, HPr, Modulates Binding Affinity to Its Natural Partners. Int J Mol Sci 2021; 22:ijms221910805. [PMID: 34639146 PMCID: PMC8509676 DOI: 10.3390/ijms221910805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/01/2021] [Accepted: 10/02/2021] [Indexed: 11/16/2022] Open
Abstract
The phosphoenolpyruvate-dependent phosphotransferase system (PTS) modulates the preferential use of sugars in bacteria. The first proteins in the cascade are common to all organisms (EI and HPr). The active site of HPr involves a histidine (His15) located immediately before the beginning of the first α-helix. The regulator of sigma D (Rsd) protein also binds to HPr. The region of HPr comprising residues Gly9-Ala30 (HPr9–30), involving the first α-helix (Ala16-Thr27) and the preceding active site loop, binds to both the N-terminal region of EI and intact Rsd. HPr9–30 is mainly disordered. We attempted to improve the affinity of HPr9–30 to both proteins by mutating its sequence to increase its helicity. We designed peptides that led to a marginally larger population in solution of the helical structure of HPr9–30. Molecular simulations also suggested a modest increment in the helical population of mutants, when compared to the wild-type. The mutants, however, were bound with a less favorable affinity than the wild-type to both the N-terminal of EI (EIN) or Rsd, as tested by isothermal titration calorimetry and fluorescence. Furthermore, mutants showed lower antibacterial properties against Staphylococcus aureus than the wild-type peptide. Therefore, we concluded that in HPr, a compromise between binding to its partners and residual structure at the active site must exist to carry out its function.
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23
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Neira JL, Palomino-Schätzlein M, Hurtado-Gómez E, Ortore MG, Falcó A. An N-terminal half fragment of the histidine phosphocarrier protein, HPr, is disordered but binds to HPr partners and shows antibacterial properties. Biochim Biophys Acta Gen Subj 2021; 1865:130015. [PMID: 34537288 DOI: 10.1016/j.bbagen.2021.130015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/26/2021] [Accepted: 09/15/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND The phosphotransferase system (PTS) modulates the preferential use of sugars in bacteria. It is formed by a protein cascade in which the first two proteins are general (namely enzyme I, EI, and the histidine phosphocarrier protein, HPr) and the others are sugar-specific permeases; the active site of HPr is His15. The HPr kinase/phosphorylase (HPrK/P), involved in the use of carbon sources in Gram-positive, phopshorylates HPr at a serine. The regulator of sigma D protein (Rsd) also binds to HPr. We are designing specific fragments of HPr, which can be used to interfere with those protein-protein interactions (PPIs), where the intact HPr intervenes. METHODS We obtained a fragment (HPr48) comprising the first forty-eight residues of HPr. HPr48 was disordered as shown by fluorescence, far-ultraviolet (UV) circular dichroism (CD), small angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR). RESULTS Secondary structure propensities, from the assigned backbone nuclei, further support the unfolded nature of the fragment. However, HPr48 was capable of binding to: (i) the N-terminal region of EI, EIN; (ii) the intact Rsd; and, (iii) HPrK/P, as shown by fluorescence, far-UV CD, NMR and biolayer interferometry (BLI). The association constants for each protein, as measured by fluorescence and BLI, were in the order of the low micromolar range, similar to those measured between the intact HPr and each of the other macromolecules. CONCLUSIONS Although HPr48 is forty-eight-residue long, it assisted antibiotics to exert antimicrobial activity. GENERAL SIGNIFICANCE HPr48 could be used as a lead compound in the development of new antibiotics, or, alternatively, to improve the efficiency of existing ones.
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Affiliation(s)
- José L Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche (Alicante), Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50018 Zaragoza, Spain.
| | | | | | - María G Ortore
- Dipartimento DiSVA, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Alberto Falcó
- IDIBE, Universidad Miguel Hernández, 03202, Elche (Alicante), Spain.
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24
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Park J, Wang HH. Systematic dissection of σ 70 sequence diversity and function in bacteria. Cell Rep 2021; 36:109590. [PMID: 34433066 PMCID: PMC8716302 DOI: 10.1016/j.celrep.2021.109590] [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: 05/18/2020] [Revised: 04/19/2021] [Accepted: 08/02/2021] [Indexed: 10/29/2022] Open
Abstract
Primary σ70 factors are key conserved bacterial regulatory proteins that interact with regulatory DNA to control gene expression. It is, however, poorly understood whether σ70 sequence diversity in different bacteria reflects functional differences. Here, we employ comparative and functional genomics to explore the sequence and function relationship of primary σ70. Using multiplex automated genome engineering and deep sequencing (MAGE-seq), we generate a saturation mutagenesis library and high-resolution fitness map of E. coli σ70 in domains 2-4. Mapping natural σ70 sequence diversity to the E. coli σ70 fitness landscape reveals significant predicted fitness deficits across σ70 orthologs. Interestingly, these predicted deficits are larger than observed fitness changes for 15 σ70 orthologs introduced into E. coli. Finally, we use a multiplexed transcriptional reporter assay and RNA sequencing (RNA-seq) to explore functional differences of several σ70 orthologs. This work provides an in-depth analysis of σ70 sequence and function to improve efforts to understand the evolution and engineering potential of this global regulator.
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Affiliation(s)
- Jimin Park
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA; Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University Irving Medical Center, New York, NY, USA.
| | - Harris H Wang
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA.
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25
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Abstract
Chloroplasts, the sites of photosynthesis and sources of reducing power, are at the core of the success story that sets apart autotrophic plants from most other living organisms. Along with their fellow organelles (e.g., amylo-, chromo-, etio-, and leucoplasts), they form a group of intracellular biosynthetic machines collectively known as plastids. These plant cell constituents have their own genome (plastome), their own (70S) ribosomes, and complete enzymatic equipment covering the full range from DNA replication via transcription and RNA processive modification to translation. Plastid RNA synthesis (gene transcription) involves the collaborative activity of two distinct types of RNA polymerases that differ in their phylogenetic origin as well as their architecture and mode of function. The existence of multiple plastid RNA polymerases is reflected by distinctive sets of regulatory DNA elements and protein factors. This complexity of the plastid transcription apparatus thus provides ample room for regulatory effects at many levels within and beyond transcription. Research in this field offers insight into the various ways in which plastid genes, both singly and groupwise, can be regulated according to the needs of the entire cell. Furthermore, it opens up strategies that allow to alter these processes in order to optimize the expression of desired gene products.
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Affiliation(s)
- Jennifer Ortelt
- Department of Biology and Biotechnology, University of Bochum, Bochum, Germany
| | - Gerhard Link
- Department of Biology and Biotechnology, University of Bochum, Bochum, Germany.
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26
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Rangel-Chávez CP, Galán-Vásquez E, Pescador-Tapia A, Delaye L, Martínez-Antonio A. RNA polymerases in strict endosymbiont bacteria with extreme genome reduction show distinct erosions that might result in limited and differential promoter recognition. PLoS One 2021; 16:e0239350. [PMID: 34324516 PMCID: PMC8321222 DOI: 10.1371/journal.pone.0239350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 06/22/2021] [Indexed: 11/26/2022] Open
Abstract
Strict endosymbiont bacteria present high degree genome reduction, retain smaller proteins, and in some instances, lack complete functional domains compared to free-living counterparts. Until now, the mechanisms underlying these genetic reductions are not well understood. In this study, the conservation of RNA polymerases, the essential machinery for gene expression, is analyzed in endosymbiont bacteria with extreme genome reductions. We analyzed the RNA polymerase subunits to identify and define domains, subdomains, and specific amino acids involved in precise biological functions known in Escherichia coli. We also perform phylogenetic analysis and three-dimensional models over four lineages of endosymbiotic proteobacteria with the smallest genomes known to date: Candidatus Hodgkinia cicadicola, Candidatus Tremblaya phenacola, Candidatus Tremblaya Princeps, Candidatus Nasuia deltocephalinicola, and Candidatus Carsonella ruddii. We found that some Hodgkinia strains do not encode for the RNA polymerase α subunit. The rest encode genes for α, β, β’, and σ subunits to form the RNA polymerase. However, 16% shorter, on average, respect their orthologous in E. coli. In the α subunit, the amino-terminal domain is the most conserved. Regarding the β and β’ subunits, both the catalytic core and the assembly domains are the most conserved. However, they showed compensatory amino acid substitutions to adapt to changes in the σ subunit. Precisely, the most erosive diversity occurs within the σ subunit. We identified broad amino acid substitution even in those recognizing and binding to the -10-box promoter element. In an overall conceptual image, the RNA polymerase from Candidatus Nasuia conserved the highest similarity with Escherichia coli RNA polymerase and their σ70. It might be recognizing the two main promoter elements (-10 and -35) and the two promoter accessory elements (-10 extended and UP-element). In Candidatus Carsonella, the RNA polymerase could recognize all the promoter elements except the -10-box extended. In Candidatus Tremblaya and Hodgkinia, due to the α carboxyl-terminal domain absence, they might not recognize the UP-promoter element. We also identified the lack of the β flap-tip helix domain in most Hodgkinia’s that suggests the inability to bind the -35-box promoter element.
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Affiliation(s)
- Cynthia Paola Rangel-Chávez
- Biological Engineering Laboratory, Genetic Engineering Department, Center for Research and Advanced Studies of the National Polytechnic Institute, Irapuato Gto, México
| | - Edgardo Galán-Vásquez
- Departamento de Ingeniería de Sistemas Computacionales y Automatización, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, CDMX, México
| | - Azucena Pescador-Tapia
- Biological Engineering Laboratory, Genetic Engineering Department, Center for Research and Advanced Studies of the National Polytechnic Institute, Irapuato Gto, México
| | - Luis Delaye
- Evolutionary Genomics Laboratory, Genetic Engineering Department, Center for Research and Advanced Studies of the National Polytechnic Institute, Irapuato Gto, México
| | - Agustino Martínez-Antonio
- Biological Engineering Laboratory, Genetic Engineering Department, Center for Research and Advanced Studies of the National Polytechnic Institute, Irapuato Gto, México
- * E-mail:
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27
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Olaniyan OT, Dare A, Okoli B, Adetunji CO, Ibitoye BO, Okotie GE, Eweoya O. Increase in SARS-CoV-2 infected biomedical waste among low middle-income countries: environmental sustainability and impact with health implications. J Basic Clin Physiol Pharmacol 2021; 33:27-44. [PMID: 34293833 DOI: 10.1515/jbcpp-2020-0533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 06/28/2021] [Indexed: 12/15/2022]
Abstract
Studies have shown that severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) is a highly infectious disease, with global deaths rising to about 360,438 as of 28 May 2020. Different countries have used various approaches such as lockdown, social distancing, maintenance of personal hygiene, and increased establishment of testing and isolation centers to manage the pandemic. Poor biomedical waste (BMW) management, treatment, and disposal techniques, especially SARS-CoV-2 infected BMW, may threaten the environmental and public health in most developing countries and, by extension, impact the economic status of individuals and the nation at large. This may increase the potential for the transmission of air/blood body fluid-borne pathogens, increase the growth of microorganisms, risk of mutagenesis, and upsurge of more virulent strain. In contrast, uncontrolled substandard burning could increase the potential spread of nosocomial infection and environmental exposure to toxic organic compounds, heavy metals, radioactive, and genotoxic bio-aerosols which might be present in the gaseous, liquid, and solid by-products. The paucity of understanding of pathophysiology and management of the SARS-CoV-2 pandemic has also necessitated the need to put in place appropriate disposal techniques to cater for the sudden increase in the global demand for personal protective equipment (PPE) and pharmaceutical drugs to manage the pandemic and to reduce the risk of preventable infection by the waste. Therefore, there is a need for adequate sensitization, awareness, and environmental monitoring of the impacts of improper handling of SARS-CoV-2 infected BMWs. Hence, this review aimed to address the issues relating to the improper management of increased SARS-CoV-2 infected BMW in low middle-income countries (LMICs).
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Affiliation(s)
- Olugbemi T Olaniyan
- Department of Physiology, Laboratory for Reproductive Biology and Developmental Programming, Edo University Iyamho, Iyamho, Nigeria
| | - Ayobami Dare
- Discipline of Physiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Bamidele Okoli
- Institute of Chemical and Biotechnology, Vaal University of Technology, Southern Gauteng Science and Technology Park, Sebokeng, South Africa
| | - Charles O Adetunji
- Department of Microbiology, Applied Microbiology, Biotechnology and Nanotechnology Laboratory, Edo University Iyamho, Iyamho, Edo State, Nigeria
| | | | - Gloria E Okotie
- Department of Physiology, University of Ibadan, Ibadan, Nigeria
| | - Olugbenga Eweoya
- Department of Anatomical Sciences, School of Medicine and Allied Health Sciences, University of the Gambia, Serekunda, The Gambia
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28
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Ishihama A, Shimada T. Hierarchy of transcription factor network in Escherichia coli K-12: H-NS-mediated silencing and Anti-silencing by global regulators. FEMS Microbiol Rev 2021; 45:6312496. [PMID: 34196371 DOI: 10.1093/femsre/fuab032] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 06/15/2021] [Indexed: 12/13/2022] Open
Abstract
Transcriptional regulation for genome expression determines growth and adaptation of single-cell bacteria that are directly exposed to environment. The transcriptional apparatus in Escherichia coli K-12 is composed of RNA polymerase core enzyme and two groups of its regulatory proteins, seven species of promoter-recognition subunit sigma and about 300 species of transcription factors. The identification of regulatory targets for all these regulatory proteins is critical toward understanding the genome regulation as a whole. For this purpose, we performed a systematic search in vitro of the whole set of binding sites for each factor by gSELEX system. This review summarizes the accumulated knowledge of regulatory targets for more than 150 TFs from E. coli K-12. Overall TFs could be classified into four families: nucleoid-associated bifunctional TFs; global regulators; local regulators; and single-target regulators, in which the regulatory functions remain uncharacterized for the nucleoid-associated TFs. Here we overview the regulatory targets of two nucleoid-associated TFs, H-NS and its paralog StpA, both together playing the silencing role of a set of non-essential genes. Participation of LeuO and other global regulators have been indicated for the anti-silencing. Finally, we propose the hierarchy of TF network as a key framework of the bacterial genome regulation.
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Affiliation(s)
- Akira Ishihama
- Hosei University, Research Institute for Micro-Nano Technology, Koganei, Tokyo 184-0003, Japan
| | - Tomohiro Shimada
- Meiji University, School of Agriculture, Kawasaki, Kanagawa 214-8571, Japan
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29
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Shimada T, Ogasawara H, Kobayashi I, Kobayashi N, Ishihama A. Single-Target Regulators Constitute the Minority Group of Transcription Factors in Escherichia coli K-12. Front Microbiol 2021; 12:697803. [PMID: 34220787 PMCID: PMC8249747 DOI: 10.3389/fmicb.2021.697803] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/28/2021] [Indexed: 11/13/2022] Open
Abstract
The identification of regulatory targets of all transcription factors (TFs) is critical for understanding the entire network of genome regulation. A total of approximately 300 TFs exist in the model prokaryote Escherichia coli K-12, but the identification of whole sets of their direct targets is impossible with use of in vivo approaches. For this end, the most direct and quick approach is to identify the TF-binding sites in vitro on the genome. We then developed and utilized the gSELEX screening system in vitro for identification of more than 150 E. coli TF-binding sites along the E. coli genome. Based on the number of predicted regulatory targets, we classified E. coli K-12 TFs into four groups, altogether forming a hierarchy ranging from a single-target TF (ST-TF) to local TFs, global TFs, and nucleoid-associated TFs controlling as many as 1,000 targets. Using the collection of purified TFs and a library of genome DNA segments from a single and the same E. coli K-12, we identified here a total of 11 novel ST-TFs, CsqR, CusR, HprR, NorR, PepA, PutA, QseA, RspR, UvrY, ZraR, and YqhC. The regulation of single-target promoters was analyzed in details for the hitherto uncharacterized QseA and RspR. In most cases, the ST-TF gene and its regulatory target genes are adjacently located on the E. coli K-12 genome, implying their simultaneous transfer in the course of genome evolution. The newly identified 11 ST-TFs and the total of 13 hitherto identified altogether constitute the minority group of TFs in E. coli K-12.
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Affiliation(s)
| | - Hiroshi Ogasawara
- Research Center for Supports to Advanced Science, Division of Gene Research, Shinshu University, Nagano, Japan.,Research Center for Fungal and Microbial Dynamism, Shinshu University, Nagano, Japan
| | - Ikki Kobayashi
- School of Agriculture, Meiji University, Kawasaki, Japan
| | - Naoki Kobayashi
- Department of Frontier Science, Hosei University, Koganei, Japan
| | - Akira Ishihama
- Department of Frontier Science, Hosei University, Koganei, Japan.,Micro-Nano Technology Research Center, Hosei University, Koganei, Japan
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30
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Zhang Y, Qiu Y, Gao H, Sun J, Li X, Zhang M, Xue X, Yang W, Ni B, Hu L, Yin Z, Lu R, Zhou D. OpaR Controls the Metabolism of c-di-GMP in Vibrio parahaemolyticus. Front Microbiol 2021; 12:676436. [PMID: 34163453 PMCID: PMC8215210 DOI: 10.3389/fmicb.2021.676436] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/30/2021] [Indexed: 11/13/2022] Open
Abstract
Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis worldwide, has a strong ability to form biofilms on surfaces. Quorum sensing (QS) is a process widely used by bacteria to communicate with each other and control gene expression via the secretion and detection of autoinducers. OpaR is the master QS regulator of V. parahaemolyticus operating under high cell density (HCD). OpaR regulation of V. parahaemolyticus biofilm formation has been reported, but the regulatory mechanisms are still not fully understood. bis-(3'-5')-cyclic di-GMP (c-di-GMP) is an omnipresent intracellular second messenger that regulates diverse behaviors of bacteria including activation of biofilm formation. In this work, we showed that OpaR repressed biofilm formation and decreased the intracellular concentration of c-di-GMP in V. parahaemolyticus RIMD2210633. The OpaR box-like sequences were detected within the regulatory DNA regions of scrA, scrG, VP0117, VPA0198, VPA1176, VP0699, and VP2979, encoding a group of GGDEF and/or EAL-type proteins. The results of qPCR, LacZ fusion, EMSA, and DNase I footprinting assays demonstrated that OpaR bound to the upstream DNA regions of scrA, VP0117, VPA0198, VPA1176, and VP0699 to repress their transcription, whereas it positively and directly regulated the transcription of scrG and VP2979. Thus, transcriptional regulation of these genes by OpaR led directly to changes in the intracellular concentration of c-di-GMP. The direct association between QS and c-di-GMP metabolism in V. parahaemolyticus RIMD2210633 would be conducive to precise control of gene transcription and bacterial behaviors such as biofilm formation.
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Affiliation(s)
- Yiquan Zhang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China.,School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yue Qiu
- School of Medicine, Jiangsu University, Zhenjiang, China
| | - He Gao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Junfang Sun
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, China
| | - Xue Li
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, China
| | - Miaomiao Zhang
- School of Medicine, Jiangsu University, Zhenjiang, China
| | - Xingfan Xue
- School of Medicine, Jiangsu University, Zhenjiang, China
| | - Wenhui Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Bin Ni
- School of Medicine, Jiangsu University, Zhenjiang, China
| | - Lingfei Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhe Yin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Renfei Lu
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
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31
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Niche dimensions of a marine bacterium are identified using invasion studies in coastal seawater. Nat Microbiol 2021; 6:524-532. [PMID: 33495621 DOI: 10.1038/s41564-020-00851-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/11/2020] [Indexed: 01/29/2023]
Abstract
Niche theory is a foundational ecological concept that explains the distribution of species in natural environments. Identifying the dimensions of any organism's niche is challenging because numerous environmental factors can affect organism viability. We used serial invasion experiments to introduce Ruegeria pomeroyi DSS-3, a heterotrophic marine bacterium, into a coastal phytoplankton bloom on 14 dates. RNA-sequencing analysis of R. pomeroyi was conducted after 90 min to assess its niche dimensions in this dynamic ecosystem. We identified ~100 external conditions eliciting transcriptional responses, which included substrates, nutrients, metals and biotic interactions such as antagonism, resistance and cofactor synthesis. The peak bloom was characterized by favourable states for most of the substrate dimensions, but low inferred growth rates of R. pomeroyi at this stage indicated that its niche was narrowed by factors other than substrate availability, most probably negative biotic interactions with the bloom dinoflagellate. Our findings indicate chemical and biological features of the ocean environment that can constrain where heterotrophic bacteria survive.
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32
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Wang H, Yang Z, Swingle B, Kvitko BH. AlgU, a Conserved Sigma Factor Regulating Abiotic Stress Tolerance and Promoting Virulence in Pseudomonas syringae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:326-336. [PMID: 33264045 DOI: 10.1094/mpmi-09-20-0254-cr] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Pseudomonas syringae can rapidly deploy specialized functions to deal with abiotic and biotic stresses. Host niches pose specific sets of environmental challenges driven, in part, by immune defenses. Bacteria use a "just-in-time" strategy of gene regulation, meaning that they only produce the functions necessary for survival as needed. Extracytoplasmic function (ECF) sigma factors transduce a specific set of environmental signals and change gene expression patterns by altering RNA polymerase promoter specificity, to adjust bacterial physiology, structure, or behavior, singly or in combination, to improve chances of survival. The broadly conserved ECF sigma factor AlgU affects virulence in both animal and plant pathogens. Pseudomonas syringae AlgU controls expression of more than 800 genes, some of which contribute to suppression of plant immunity and bacterial fitness in plants. This review discusses AlgU activation mechanisms, functions controlled by AlgU, and how these functions contribute to P. syringae survival in plants.[Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. 2021.
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Affiliation(s)
- Haibi Wang
- Department of Plant Pathology, University of Georgia, 120 Carlton St., Athens, GA 30602, U.S.A
| | - Zichu Yang
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, 334 Plant Science Bldg., Ithaca, NY 14853, U.S.A
| | - Bryan Swingle
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, 334 Plant Science Bldg., Ithaca, NY 14853, U.S.A
- Emerging Pests and Pathogens Research Unit, Robert W. Holley Center, United States Department of Agriculture-Agricultural Research Service, Ithaca, NY 14853, U.S.A
| | - Brian H Kvitko
- Department of Plant Pathology, University of Georgia, 120 Carlton St., Athens, GA 30602, U.S.A
- The Plant Center, University of Georgia, Athens, GA 30602, U.S.A
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33
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The Context-Dependent Influence of Promoter Sequence Motifs on Transcription Initiation Kinetics and Regulation. J Bacteriol 2021; 203:JB.00512-20. [PMID: 33139481 DOI: 10.1128/jb.00512-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The fitness of an individual bacterial cell is highly dependent upon the temporal tuning of gene expression levels when subjected to different environmental cues. Kinetic regulation of transcription initiation is a key step in modulating the levels of transcribed genes to promote bacterial survival. The initiation phase encompasses the binding of RNA polymerase (RNAP) to promoter DNA and a series of coupled protein-DNA conformational changes prior to entry into processive elongation. The time required to complete the initiation phase can vary by orders of magnitude and is ultimately dictated by the DNA sequence of the promoter. In this review, we aim to provide the required background to understand how promoter sequence motifs may affect initiation kinetics during promoter recognition and binding, subsequent conformational changes which lead to DNA opening around the transcription start site, and promoter escape. By calculating the steady-state flux of RNA production as a function of these effects, we illustrate that the presence/absence of a consensus promoter motif cannot be used in isolation to make conclusions regarding promoter strength. Instead, the entire series of linked, sequence-dependent structural transitions must be considered holistically. Finally, we describe how individual transcription factors take advantage of the broad distribution of sequence-dependent basal kinetics to either increase or decrease RNA flux.
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34
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Zhang Y, Qiu Y, Xue X, Zhang M, Sun J, Li X, Hu L, Yin Z, Yang W, Lu R, Zhou D. Transcriptional regulation of the virulence genes and the biofilm formation associated operons in Vibrio parahaemolyticus. Gut Pathog 2021; 13:15. [PMID: 33653369 PMCID: PMC7923509 DOI: 10.1186/s13099-021-00410-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/23/2021] [Indexed: 11/10/2022] Open
Abstract
Background The membrane fusion protein (mfp) gene locus of Vibrio parahaemolyticus consists of two operons, cpsQ-mfpABC and mfpABC, which are both required for biofilm formation. ToxR and CalR are required for the full virulence of V. parahaemolyticus, and their mutual regulation has been demonstrated. Moreover, cell density-dependent expression of toxR was previously observed in V. parahaemolyticus, but details about the related mechanisms remained unclear. QsvR can work with the master quorum sensing (QS) regulators AphA and OpaR to regulate virulence expression and biofilm formation. Results In the present work, we showed that QsvR bound to the promoter-proximal DNA regions of toxR and calR to repress their transcription as well as occupying the regulatory regions of cpsQ-mfpABC and mfpABC to activate their transcription. Thus, we reconstructed the QsvR-dependent promoter organization of toxR, calR, cpsQ-mfpABC, and mfpABC. Conclusion QsvR directly repressed toxR and calR transcription as well as directly activated cpsQ-mfpABC and mfpABC transcription. The data presented here promotes us to gain deeper knowledge of the regulatory network of the mfp locus in V. parahaemolyticus.
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Affiliation(s)
- Yiquan Zhang
- Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, Jiangsu, China. .,School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China.
| | - Yue Qiu
- School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Xingfan Xue
- School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Miaomiao Zhang
- School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Junfang Sun
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, 212006, Jiangsu, China
| | - Xue Li
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, 212006, Jiangsu, China
| | - Lingfei Hu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Zhe Yin
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Wenhui Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Renfei Lu
- Department of Clinical Laboratory, Nantong Third Hospital Affiliated to Nantong University, Nantong, 212006, Jiangsu, China.
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China.
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35
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Hinzke T, Kleiner M, Meister M, Schlüter R, Hentschker C, Pané-Farré J, Hildebrandt P, Felbeck H, Sievert SM, Bonn F, Völker U, Becher D, Schweder T, Markert S. Bacterial symbiont subpopulations have different roles in a deep-sea symbiosis. eLife 2021; 10:58371. [PMID: 33404502 PMCID: PMC7787665 DOI: 10.7554/elife.58371] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 12/05/2020] [Indexed: 12/13/2022] Open
Abstract
The hydrothermal vent tubeworm Riftia pachyptila hosts a single 16S rRNA phylotype of intracellular sulfur-oxidizing symbionts, which vary considerably in cell morphology and exhibit a remarkable degree of physiological diversity and redundancy, even in the same host. To elucidate whether multiple metabolic routes are employed in the same cells or rather in distinct symbiont subpopulations, we enriched symbionts according to cell size by density gradient centrifugation. Metaproteomic analysis, microscopy, and flow cytometry strongly suggest that Riftia symbiont cells of different sizes represent metabolically dissimilar stages of a physiological differentiation process: While small symbionts actively divide and may establish cellular symbiont-host interaction, large symbionts apparently do not divide, but still replicate DNA, leading to DNA endoreduplication. Moreover, in large symbionts, carbon fixation and biomass production seem to be metabolic priorities. We propose that this division of labor between smaller and larger symbionts benefits the productivity of the symbiosis as a whole.
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Affiliation(s)
- Tjorven Hinzke
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany.,Energy Bioengineering Group, University of Calgary, Calgary, Canada
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, United States
| | - Mareike Meister
- Institute of Microbiology, University of Greifswald, Greifswald, Germany.,Leibniz Institute for Plasma Science and Technology, Greifswald, Germany
| | - Rabea Schlüter
- Imaging Center of the Department of Biology, University of Greifswald, Greifswald, Germany
| | - Christian Hentschker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jan Pané-Farré
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Petra Hildebrandt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Horst Felbeck
- Scripps Institution of Oceanography, University of California San Diego, San Diego, United States
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, United States
| | - Florian Bonn
- Institute of Biochemistry, University Hospital, Goethe University School of Medicine Frankfurt, Frankfurt, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, Greifswald, Germany
| | - Thomas Schweder
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany
| | - Stephanie Markert
- Institute of Pharmacy, University of Greifswald, Greifswald, Germany.,Institute of Marine Biotechnology, Greifswald, Germany
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Davey JA, Wilson CJ. Engineered signal-coupled inducible promoters: measuring the apparent RNA-polymerase resource budget. Nucleic Acids Res 2020; 48:9995-10012. [PMID: 32890400 PMCID: PMC7515704 DOI: 10.1093/nar/gkaa734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 02/07/2023] Open
Abstract
Inducible promoters are a central regulatory component in synthetic biology, metabolic engineering, and protein production for laboratory and commercial uses. Many of these applications utilize two or more exogenous promoters, imposing a currently unquantifiable metabolic burden on the living system. Here, we engineered a collection of inducible promoters (regulated by LacI-based transcription factors) that maximize the free-state of endogenous RNA polymerase (RNAP). We leveraged this collection of inducible promotors to construct simple two-channel logical controls that enabled us to measure metabolic burden – as it relates to RNAP resource partitioning. The two-channel genetic circuits utilized sets of signal-coupled transcription factors that regulate cognate inducible promoters in a coordinated logical fashion. With this fundamental genetic architecture, we evaluated the performance of each inducible promoter as discrete operations, and as coupled systems to evaluate and quantify the effects of resource partitioning. Obtaining the ability to systematically and accurately measure the apparent RNA-polymerase resource budget will enable researchers to design more robust genetic circuits, with significantly higher fidelity. Moreover, this study presents a workflow that can be used to better understand how living systems adapt RNAP resources, via the complementary pairing of constitutive and regulated promoters that vary in strength.
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Affiliation(s)
- James A Davey
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, 311 Ferst Drive, Atlanta, GA 30332-0100, USA
| | - Corey J Wilson
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, 311 Ferst Drive, Atlanta, GA 30332-0100, USA
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37
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Wettstadt S, Llamas MA. Role of Regulated Proteolysis in the Communication of Bacteria With the Environment. Front Mol Biosci 2020; 7:586497. [PMID: 33195433 PMCID: PMC7593790 DOI: 10.3389/fmolb.2020.586497] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/22/2020] [Indexed: 12/29/2022] Open
Abstract
For bacteria to flourish in different niches, they need to sense signals from the environment and translate these into appropriate responses. Most bacterial signal transduction systems involve proteins that trigger the required response through the modification of gene transcription. These proteins are often produced in an inactive state that prevents their interaction with the RNA polymerase and/or the DNA in the absence of the inducing signal. Among other mechanisms, regulated proteolysis is becoming increasingly recognized as a key process in the modulation of the activity of these signal response proteins. Regulated proteolysis can either produce complete degradation or specific cleavage of the target protein, thus modifying its function. Because proteolysis is a fast process, the modulation of signaling proteins activity by this process allows for an immediate response to a given signal, which facilitates adaptation to the surrounding environment and bacterial survival. Moreover, regulated proteolysis is a fundamental process for the transmission of extracellular signals to the cytosol through the bacterial membranes. By a proteolytic mechanism known as regulated intramembrane proteolysis (RIP) transmembrane proteins are cleaved within the plane of the membrane to liberate a cytosolic domain or protein able to modify gene transcription. This allows the transmission of a signal present on one side of a membrane to the other side where the response is elicited. In this work, we review the role of regulated proteolysis in the bacterial communication with the environment through the modulation of the main bacterial signal transduction systems, namely one- and two-component systems, and alternative σ factors.
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Affiliation(s)
- Sarah Wettstadt
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - María A Llamas
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
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38
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Abstract
The correct mapping of promoter elements is a crucial step in microbial genomics. Also, when combining new DNA elements into synthetic sequences, predicting the potential generation of new promoter sequences is critical. Over the last years, many bioinformatics tools have been created to allow users to predict promoter elements in a sequence or genome of interest. Here, we assess the predictive power of some of the main prediction tools available using well-defined promoter data sets. Using Escherichia coli as a model organism, we demonstrated that while some tools are biased toward AT-rich sequences, others are very efficient in identifying real promoters with low false-negative rates. We hope the potentials and limitations presented here will help the microbiology community to choose promoter prediction tools among many available alternatives. The promoter region is a key element required for the production of RNA in bacteria. While new high-throughput technology allows massively parallel mapping of promoter elements, we still mainly rely on bioinformatics tools to predict such elements in bacterial genomes. Additionally, despite many different prediction tools having become popular to identify bacterial promoters, no systematic comparison of such tools has been performed. Here, we performed a systematic comparison between several widely used promoter prediction tools (BPROM, bTSSfinder, BacPP, CNNProm, IBBP, Virtual Footprint, iPro70-FMWin, 70ProPred, iPromoter-2L, and MULTiPly) using well-defined sequence data sets and standardized metrics to determine how well those tools performed related to each other. For this, we used data sets of experimentally validated promoters from Escherichia coli and a control data set composed of randomly generated sequences with similar nucleotide distributions. We compared the performance of the tools using metrics such as specificity, sensitivity, accuracy, and Matthews correlation coefficient (MCC). We show that the widely used BPROM presented the worse performance among the compared tools, while four tools (CNNProm, iPro70-FMWin, 70ProPred, and iPromoter-2L) offered high predictive power. Of these tools, iPro70-FMWin exhibited the best results for most of the metrics used. We present here some potentials and limitations of available tools, and we hope that future work can build upon our effort to systematically characterize this useful class of bioinformatics tools. IMPORTANCE The correct mapping of promoter elements is a crucial step in microbial genomics. Also, when combining new DNA elements into synthetic sequences, predicting the potential generation of new promoter sequences is critical. Over the last years, many bioinformatics tools have been created to allow users to predict promoter elements in a sequence or genome of interest. Here, we assess the predictive power of some of the main prediction tools available using well-defined promoter data sets. Using Escherichia coli as a model organism, we demonstrated that while some tools are biased toward AT-rich sequences, others are very efficient in identifying real promoters with low false-negative rates. We hope the potentials and limitations presented here will help the microbiology community to choose promoter prediction tools among many available alternatives.
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39
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Hu L, Wang C, Lu W, Lu H, Chen H, Tan C. BaeSR activates type VI secretion system expression in porcine extra-intestinal pathogenic Escherichia coli to enhance bacterial resistance to zinc stress. Microb Pathog 2020; 147:104357. [PMID: 32603765 DOI: 10.1016/j.micpath.2020.104357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/24/2022]
Abstract
The two-component system BaeSR is an extra-cytoplasmic stress response system in Escherichia coli, whose function is to be adapted to environmental stress. Recently, we have identified an active type VI secretion system in porcine extra-intestinal pathogenic Escherichia coli PCN033. DNA-protein interactions shows that BaeR directly binds to the promoter region of the T6SS and then induces its expression. Deletion of baeR/baeSR decreased zinc resistance of bacteria. Moreover, T6SS mutant Δhcp1/hcp2/hcp3 is more sensitive than wild type after exposure to external zinc, and complementation of hcp1 largely restored growth defect. Our study uncovers a new regulation mechanism of BaeSR system in response to metal stress. It reveals that BaeR-regulated T6SS is critical for bacteria survival under toxic zinc condition. In conclusion, T6SS contributes to zinc stress resistance in a BaeSR system-dependent manner.
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Affiliation(s)
- Linlin Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Chenchen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Wenjia Lu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Hao Lu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, Hubei, China; Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan, Hubei, 430070, China.
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40
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Identification of Substrates of Cytoplasmic Peptidyl-Prolyl Cis/Trans Isomerases and Their Collective Essentiality in Escherichia Coli. Int J Mol Sci 2020; 21:ijms21124212. [PMID: 32545723 PMCID: PMC7353009 DOI: 10.3390/ijms21124212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/07/2020] [Accepted: 06/09/2020] [Indexed: 11/16/2022] Open
Abstract
Protein folding often requires molecular chaperones and folding catalysts, such as peptidyl-prolyl cis/trans isomerases (PPIs). The Escherichia coli cytoplasm contains six well-known PPIs, although a requirement of their PPIase activity, the identity of their substrates and relative enzymatic contribution is unknown. Thus, strains lacking all periplasmic and one of the cytoplasmic PPIs were constructed. Measurement of their PPIase activity revealed that PpiB is the major source of PPIase activity in the cytoplasm. Furthermore, viable Δ6ppi strains could be constructed only on minimal medium in the temperature range of 30-37 °C, but not on rich medium. To address the molecular basis of essentiality of PPIs, proteins that aggregate in their absence were identified. Next, wild-type and putative active site variants of FkpB, FklB, PpiB and PpiC were purified and in pull-down experiments substrates specific to each of these PPIs identified, revealing an overlap of some substrates. Substrates of PpiC were validated by immunoprecipitations using extracts from wild-type and PpiC-H81A strains carrying a 3xFLAG-tag appended to the C-terminal end of the ppiC gene on the chromosome. Using isothermal titration calorimetry, RpoE, RseA, S2, and AhpC were established as FkpB substrates and PpiC's PPIase activity was shown to be required for interaction with AhpC.
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Xie DF, Tan JB, Yu Y, Gui LJ, Su DM, Zhou SD, He XJ. Insights into phylogeny, age and evolution of Allium (Amaryllidaceae) based on the whole plastome sequences. ANNALS OF BOTANY 2020; 125:1039-1055. [PMID: 32239179 PMCID: PMC7262478 DOI: 10.1093/aob/mcaa024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 04/01/2020] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS The genus Allium L., one of the largest monocotyledonous genera and one that includes many economically important crops with nutritional and medicinal value, has been the focus of classification or phylogeny studies for centuries. Recent studies suggested that the genus can be divided into 15 subgenera and 72 sections, which were further classified into three evolutionary lineages. However, the phylogenetic relationships reconstructed by one or two loci showed weaker support, especially for the third evolutionary lineage, which might not show the species relationships very clearly and could hinder further adaptive and evolutionary study. METHODS In this study, a total of 39 complete chloroplast genomes of Allium (covering 12 Allium subgenera) were collected, and combining these with 125 species of plastomes from 19 other families of monocots, we reconstructed the phylogeny of the genus Allium, estimated the origin and divergence time of the three evolutionary lineages and investigated the adaptive evolution in this genus and related families. RESULTS Our phylogenetic analysis confirmed the monophyly and three evolutionary lineages of Allium, while new species relationships were detected within the third evolutionary lineage. The divergence time of the three evolutionary lineages was estimated to be in the early Eocene to the middle Miocene, and numerous positive selected genes (PSGs) and PSGs with high average Ka/Ks values were found in Allium species. CONCLUSIONS Our results detected a well-supported phylogenetic relationship of Allium. The PSGs and PSGs with high Ka/Ks values, as well as diversified morphologies, complicated chromosome characteristics and unique reproductive modes may play important roles in the adaptation and evolution of Allium species. This is the first study that conducted phylogenetic and evolutionary analyses on the genus Allium combined with the plastome and morphological and cytological data. We hope that this study can contribute to further analysis of Allium for other researchers.
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Affiliation(s)
- Deng-Feng Xie
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Jin-Bo Tan
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Yan Yu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Lin-Jian Gui
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Dan-Mei Su
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Song-Dong Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
| | - Xing-Jin He
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, People’s Republic of China
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Zhang T, Shi XC, Ding R, Xu K, Tremblay PL. The hidden chemolithoautotrophic metabolism of Geobacter sulfurreducens uncovered by adaptation to formate. ISME JOURNAL 2020; 14:2078-2089. [PMID: 32398660 DOI: 10.1038/s41396-020-0673-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 02/01/2023]
Abstract
Multiple Fe(III)-reducing Geobacter species including the model Geobacter sulfurreducens are thought to be incapable of carbon dioxide fixation. The discovery of the reversed oxidative tricarboxylic acid cycle (roTCA) for CO2 reduction with citrate synthase as key enzyme raises the possibility that G. sulfurreducens harbors the metabolic potential for chemolithoautotrophic growth. We investigate this hypothesis by transferring G. sulfurreducens PCA serially with Fe(III) as electron acceptor and formate as electron donor and carbon source. The evolved strain T17-3 grew chemolithoautotrophically with a 2.7-fold population increase over 48 h and a Fe(III) reduction rate of 417.5 μM h-1. T17-3 also grew with CO2 as carbon source. Mutations in T17-3 and enzymatic assays point to an adaptation process where the succinyl-CoA synthetase, which is inactive in the wild-type, became active to complete the roTCA cycle. Deletion of the genes coding for the succinyl-CoA synthetase in T17-3 prevented growth with formate as substrate. Enzymatic assays also showed that the citrate synthase can perform the necessary cleavage of citrate for the functional roTCA cycle. These results demonstrate that G. sulfurreducens after adaptation reduced CO2 via the roTCA cycle. This previously hidden metabolism can be harnessed for biotechnological applications and suggests hidden ecological functions for Geobacter.
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Affiliation(s)
- Tian Zhang
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China.
| | - Xiao-Chen Shi
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Ran Ding
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China.,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Kai Xu
- Center for Material Research and Analysis, Wuhan University of Technology, Wuhan, 430070, PR China
| | - Pier-Luc Tremblay
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan, 430070, PR China. .,School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, PR China.
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Gao H, Zhang J, Lou J, Li J, Qin Q, Shi Q, Zhang Y, Kan B. Direct Binding and Regulation by Fur and HapR of the Intermediate Regulator and Virulence Factor Genes Within the ToxR Virulence Regulon in Vibrio cholerae. Front Microbiol 2020; 11:709. [PMID: 32362889 PMCID: PMC7181404 DOI: 10.3389/fmicb.2020.00709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/26/2020] [Indexed: 01/30/2023] Open
Abstract
Cholera toxin (CT) and toxin coregulated pilus (TCP, TcpA is the major subunit) are two major virulence factors of Vibrio cholerae, both of which play critical roles in developing severe diarrhea in human. Expression of CT and TCP is under the tight control of the regulatory cascade known as the ToxR virulence regulon, which is composed of three regulators ToxR, TcpP, and ToxT. Besides, their expression is also regulated by the quorum sensing (QS) master regulator HapR and the regulatory protein Fur. Though transcription of tcpP, toxT, and/or tcpA are reported to be regulated by HapR and Fur, to date there are no studies to verify their direct regulations. In the present study, we showed that HapR directly repress the transcription of tcpP and tcpA by binding to their promoter regions, and possibly repress toxT transcription in an indirect manner. Fur directly activated the transcription of tcpP, toxT, and tcpA by binding to their promoters. Taking account of the sequential expression of hapR, fur, tcpP, toxT, and tcpA in the different growth phases of V. cholerae, we deduce that at the early mid-logarithmic growth phase, Fur binds to the promoters of tcpP, toxT, and tcpA to activate their transcription; while at the later mid-logarithmic growth phase, HapR can bind to the promoters of tcpP and tcpA to repress their transcription. Our study reveals the new recognition in the virulence regulatory pathways in V. cholerae and suggests the complicated and subtle regulation network with the growth density dependence.
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Affiliation(s)
- He Gao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jingyun Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jing Lou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jie Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qin Qin
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qiannan Shi
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yiquan Zhang
- School of Medicine, Jiangsu University, Zhenjiang, China
| | - Biao Kan
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Otero-Asman JR, Quesada JM, Jim KK, Ocampo-Sosa A, Civantos C, Bitter W, Llamas MA. The extracytoplasmic function sigma factor σ VreI is active during infection and contributes to phosphate starvation-induced virulence of Pseudomonas aeruginosa. Sci Rep 2020; 10:3139. [PMID: 32081993 PMCID: PMC7035377 DOI: 10.1038/s41598-020-60197-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/07/2020] [Indexed: 12/27/2022] Open
Abstract
The extracytoplasmic function sigma factor σVreI of the human pathogen Pseudomonas aeruginosa promotes transcription of potential virulence determinants, including secretion systems and secreted proteins. Its activity is modulated by the VreR anti-σ factor that inhibits the binding of σVreI to the RNA polymerase in the absence of a (still unknown) inducing signal. The vreI-vreR genes are expressed under inorganic phosphate (Pi) starvation, a physiological condition often encountered in the host that increases P. aeruginosa pathogenicity. However, whether or not σVreI is active in vivo during infection and contributes to the Pi starvation-induced virulence of this pathogen has not been analyzed yet. Using zebrafish embryos and a human alveolar basal epithelial cell line as P. aeruginosa hosts, we demonstrate in this work that σVreI is active during infection and that lack of σVreI considerably reduces the Pi starvation-induced virulence of this pathogen. Surprisingly, lack of the σVreI inhibitor, the VreR anti-σ factor, also diminishes the virulence of P. aeruginosa. By transcriptomic analyses we show that VreR modulates gene expression not only in a σVreI-dependent but also in a σVreI-independent manner. This includes potential virulence determinants and transcriptional regulators that could be responsible for the reduced virulence of the ΔvreR mutant.
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Affiliation(s)
- Joaquín R Otero-Asman
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - José M Quesada
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Kin K Jim
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centers, location VU University, Amsterdam, The Netherlands
| | - Alain Ocampo-Sosa
- Service of Microbiology, Hospital Universitario Marqués de Valdecilla-Instituto de Investigación Sanitaria Valdecilla, Santander, Spain
| | - Cristina Civantos
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Wilbert Bitter
- Department of Medical Microbiology and Infection Control, Amsterdam University medical centers, location VU University, Amsterdam, The Netherlands
| | - María A Llamas
- Department of Environmental Protection, Estación Experimental del Zaidín-Consejo Superior de Investigaciones Científicas, Granada, Spain.
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Shimada T, Yokoyama Y, Anzai T, Yamamoto K, Ishihama A. Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12. Sci Rep 2019; 9:20415. [PMID: 31892694 PMCID: PMC6958661 DOI: 10.1038/s41598-019-56886-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 12/18/2019] [Indexed: 12/13/2022] Open
Abstract
Outside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization). The natural hosts of enterobacterium Escherichia coli are warm-blooded animals, but even outside hosts, E. coli can survive even under stressful environments. On earth, the most common organic materials to be used as nutrients by E. coli are plant-derived components, but up to the present time, the genetic system of E. coli for plant utilization is poorly understand. In the course of gSELEX screening of the regulatory targets for hitherto uncharacterized TFs, we identified in this study the involvement of the IclR-family YiaJ in the regulation of about 20 genes or operons, of which the majority are related to the catabolism of plant-derived materials such as ascorbate, galacturonate, sorbitol, fructose and fructoselysine. Therefore, we propose to rename YiaJ to PlaR (regulator of plant utilization).
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Affiliation(s)
- Tomohiro Shimada
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan. .,Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan.
| | - Yui Yokoyama
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Takumi Anzai
- Meiji University, School of Agriculture, Kawasaki, Kanagawa, 214-8571, Japan
| | - Kaneyoshi Yamamoto
- Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan
| | - Akira Ishihama
- Hosei University, Research Institute of Micro-Nano Technology, Koganei, Tokyo, 184-0003, Japan. .,Hosei University, Department of Frontier Bioscience, Koganei, Tokyo, 184-8584, Japan.
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46
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Muskhelishvili G, Forquet R, Reverchon S, Meyer S, Nasser W. Coherent Domains of Transcription Coordinate Gene Expression During Bacterial Growth and Adaptation. Microorganisms 2019; 7:microorganisms7120694. [PMID: 31847191 PMCID: PMC6956064 DOI: 10.3390/microorganisms7120694] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/28/2019] [Accepted: 12/09/2019] [Indexed: 01/07/2023] Open
Abstract
Recent studies strongly suggest that in bacteria, both the genomic pattern of DNA thermodynamic stability and the order of genes along the chromosomal origin-to-terminus axis are highly conserved and that this spatial organization plays a crucial role in coordinating genomic transcription. In this article, we explore the relationship between genomic sequence organization and transcription in the commensal bacterium Escherichia coli and the plant pathogen Dickeya. We argue that, while in E. coli the gradient of DNA thermodynamic stability and gene order along the origin-to-terminus axis represent major organizational features orchestrating temporal gene expression, the genomic sequence organization of Dickeya is more complex, demonstrating extended chromosomal domains of thermodynamically distinct DNA sequences eliciting specific transcriptional responses to various kinds of stress encountered during pathogenic growth. This feature of the Dickeya genome is likely an adaptation to the pathogenic lifestyle utilizing differences in genomic sequence organization for the selective expression of virulence traits. We propose that the coupling of DNA thermodynamic stability and genetic function provides a common organizational principle for the coordinated expression of genes during both normal and pathogenic bacterial growth.
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Affiliation(s)
| | - Raphaël Forquet
- INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, Univ. Lyon, Université Lyon 1, F-69622 Villeurbanne, France; (R.F.); (S.R.); (S.M.)
| | - Sylvie Reverchon
- INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, Univ. Lyon, Université Lyon 1, F-69622 Villeurbanne, France; (R.F.); (S.R.); (S.M.)
| | - Sam Meyer
- INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, Univ. Lyon, Université Lyon 1, F-69622 Villeurbanne, France; (R.F.); (S.R.); (S.M.)
| | - William Nasser
- INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, Univ. Lyon, Université Lyon 1, F-69622 Villeurbanne, France; (R.F.); (S.R.); (S.M.)
- Correspondence:
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Yoshida H, Wada A, Shimada T, Maki Y, Ishihama A. Coordinated Regulation of Rsd and RMF for Simultaneous Hibernation of Transcription Apparatus and Translation Machinery in Stationary-Phase Escherichia coli. Front Genet 2019; 10:1153. [PMID: 31867037 PMCID: PMC6904343 DOI: 10.3389/fgene.2019.01153] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 10/22/2019] [Indexed: 02/01/2023] Open
Abstract
Transcription and translation in growing phase of Escherichia coli, the best-studied model prokaryote, are coupled and regulated in coordinate fashion. Accordingly, the growth rate-dependent control of the synthesis of RNA polymerase (RNAP) core enzyme (the core component of transcription apparatus) and ribosomes (the core component of translation machinery) is tightly coordinated to keep the relative level of transcription apparatus and translation machinery constant for effective and efficient utilization of resources and energy. Upon entry into the stationary phase, transcription apparatus is modulated by replacing RNAP core-associated sigma (promoter recognition subunit) from growth-related RpoD to stationary-phase-specific RpoS. The anti-sigma factor Rsd participates for the efficient replacement of sigma, and the unused RpoD is stored silent as Rsd–RpoD complex. On the other hand, functional 70S ribosome is transformed into inactive 100S dimer by two regulators, ribosome modulation factor (RMF) and hibernation promoting factor (HPF). In this review article, we overview how we found these factors and what we know about the molecular mechanisms for silencing transcription apparatus and translation machinery by these factors. In addition, we provide our recent findings of promoter-specific transcription factor (PS-TF) screening of the transcription factors involved in regulation of the rsd and rmf genes. Results altogether indicate the coordinated regulation of Rsd and RMF for simultaneous hibernation of transcription apparatus and translation machinery.
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Affiliation(s)
- Hideji Yoshida
- Department of Physics, Osaka Medical College, Takatsuki, Japan
| | - Akira Wada
- Yoshida Biological Laboratory, Kyoto, Japan
| | - Tomohiro Shimada
- School of Agriculture, Meiji University, Kawasaki, Japan.,Research Center for Micro-Nano Technology, Hosei University, Koganei, Japan
| | - Yasushi Maki
- Department of Physics, Osaka Medical College, Takatsuki, Japan
| | - Akira Ishihama
- Research Center for Micro-Nano Technology, Hosei University, Koganei, Japan
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Sun Z, Cagliero C, Izard J, Chen Y, Zhou YN, Heinz WF, Schneider TD, Jin DJ. Density of σ70 promoter-like sites in the intergenic regions dictates the redistribution of RNA polymerase during osmotic stress in Escherichia coli. Nucleic Acids Res 2019; 47:3970-3985. [PMID: 30843055 DOI: 10.1093/nar/gkz159] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 11/14/2022] Open
Abstract
RNA polymerase (RNAP), the transcription machinery, shows dynamic binding across the genomic DNA under different growth conditions. The genomic features that selectively redistribute the limited RNAP molecules to dictate genome-wide transcription in response to environmental cues remain largely unknown. We chose the bacterial osmotic stress response model to determine genomic features that direct genome-wide redistribution of RNAP during the stress. Genomic mapping of RNAP and transcriptome profiles corresponding to the different temporal states after salt shock were determined. We found rapid redistribution of RNAP across the genome, primarily at σ70 promoters. Three subsets of genes exhibiting differential salt sensitivities were identified. Sequence analysis using an information-theory based σ70 model indicates that the intergenic regions of salt-responsive genes are enriched with a higher density of σ70 promoter-like sites than those of salt-sensitive genes. In addition, the density of promoter-like sites has a positive linear correlation with RNAP binding at different salt concentrations. The RNAP binding contributed by the non-initiating promoter-like sites is important for gene transcription at high salt concentration. Our study demonstrates that hyperdensity of σ70 promoter-like sites in the intergenic regions of salt-responsive genes drives the RNAP redistribution for reprograming the transcriptome to counter osmotic stress.
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Affiliation(s)
- Zhe Sun
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Cedric Cagliero
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Jerome Izard
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yixiong Chen
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yan Ning Zhou
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - William F Heinz
- Optical Microscopy and Analysis Laboratory, Frederick National Laboratory for Cancer Research sponsored by the National Cancer Institute, Frederick, MD 21702, USA
| | - Thomas D Schneider
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Ding Jun Jin
- RNA Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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Spatial organization of RNA polymerase and its relationship with transcription in Escherichia coli. Proc Natl Acad Sci U S A 2019; 116:20115-20123. [PMID: 31527272 DOI: 10.1073/pnas.1903968116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent studies have shown that RNA polymerase (RNAP) is organized into distinct clusters in Escherichia coli and Bacillus subtilis cells. Spatially organized molecular components in prokaryotic systems imply compartmentalization without the use of membranes, which may offer insights into unique functions and regulations. It has been proposed that the formation of RNAP clusters is driven by active ribosomal RNA (rRNA) transcription and that RNAP clusters function as factories for highly efficient transcription. In this work, we examined these hypotheses by investigating the spatial organization and transcription activity of RNAP in E. coli cells using quantitative superresolution imaging coupled with genetic and biochemical assays. We observed that RNAP formed distinct clusters that were engaged in active rRNA synthesis under a rich medium growth condition. Surprisingly, a large fraction of RNAP clusters persisted in the absence of high rRNA transcription activities or when the housekeeping σ70 was sequestered, and was only significantly diminished when all RNA transcription was inhibited globally. In contrast, the cellular distribution of RNAP closely followed the morphology of the underlying nucleoid under all conditions tested irrespective of the corresponding transcription activity, and RNAP redistributed into dispersed, smaller clusters when the supercoiling state of the nucleoid was perturbed. These results suggest that RNAP was organized into active transcription centers under the rich medium growth condition; its spatial arrangement at the cellular level, however, was not dependent on rRNA synthesis activity and was likely organized by the underlying nucleoid.
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Liu Q, Li M, Teng Y, Yang H, Xi Y, Chen S, Duan G. The role of cfa gene in ampicillin tolerance in Shigella. Infect Drug Resist 2019; 12:2765-2774. [PMID: 31686867 PMCID: PMC6737898 DOI: 10.2147/idr.s211550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/12/2019] [Indexed: 11/29/2022] Open
Abstract
Background Bacterial dysentery is an intestinal infectious disease caused by Shigella. The resistance of Shigella species to ampicillin has increased rapidly. Besides resistance, bacteria in a state of tolerance to antibiotics can also lead to the failure of infectious diseases therapy. Purpose The genetic mechanism of antibiotic tolerance remains largely unexplored. The current study aimed to investigate the mechanisms of antibiotic tolerance and to provide novel strategies for the prevention of drug resistance of Shigella. Methods We exposed Shigella to lethal doses of ampicillin to obtain tolerant strain. The tolerant strain was sequenced to screen non-single-nucleotide polymorphisms and Indels. We also quantitated the relative expression of gene by RT-PCR. Results There was one nonsynonymous mutation in the 2252304 loci of the cfa gene (G to A/Val to Met) and 10 Indels in the noncoding regions of different genes. The expression of the cfa gene was 7.56-fold higher in the tolerant strain than in the wild-type strain. Conclusion Our results showed that Shigella could be tolerated to ampicillin, and the cfa gene might be associated with antibiotic tolerance by increasing its expression. Our data suggest that cfa gene might be a target for overcoming drug tolerance, delaying the occurrence of drug resistance to some extent. ![]()
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Affiliation(s)
- Qiaoli Liu
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Mengchen Li
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Yanli Teng
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Haiyan Yang
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Yuanli Xi
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Shuaiyin Chen
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Guangcai Duan
- Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, People's Republic of China
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