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Moon S, Ham S, Jeong J, Ku H, Kim H, Lee C. Temperature Matters: Bacterial Response to Temperature Change. J Microbiol 2023; 61:343-357. [PMID: 37010795 DOI: 10.1007/s12275-023-00031-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/13/2023] [Accepted: 02/13/2023] [Indexed: 04/04/2023]
Abstract
Temperature is one of the most important factors in all living organisms for survival. Being a unicellular organism, bacterium requires sensitive sensing and defense mechanisms to tolerate changes in temperature. During a temperature shift, the structure and composition of various cellular molecules including nucleic acids, proteins, and membranes are affected. In addition, numerous genes are induced during heat or cold shocks to overcome the cellular stresses, which are known as heat- and cold-shock proteins. In this review, we describe the cellular phenomena that occur with temperature change and bacterial responses from a molecular perspective, mainly in Escherichia coli.
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Affiliation(s)
- Seongjoon Moon
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Soojeong Ham
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Juwon Jeong
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Heechan Ku
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Hyunhee Kim
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea.
| | - Changhan Lee
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea.
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2
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Zhao W, Peng D, Li W, Chen S, Liu B, Huang P, Wu J, Du B, Li P. Probiotic-fermented Pueraria lobata (Willd.) Ohwi alleviates alcoholic liver injury by enhancing antioxidant defense and modulating gut microbiota. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:6877-6888. [PMID: 35655427 DOI: 10.1002/jsfa.12049] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/30/2022] [Accepted: 06/03/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Pueraria lobata (Willd.) Ohwi (PL) has been used in China to detoxify alcohol and protect the liver for millennia, though its mechanism of liver protection has not been elucidated. However, fermentation is considered to be one of the effective ways to enhance the efficacy of traditional Chinese medicine. The aim of this study was to investigate the hepatoprotective mechanism of probiotic-fermented PL (FPL). Sprague Dawley rats were administered with FPL followed by gavage of alcohol for seven consecutive days; following that, liver injury levels were evaluated in rats. RESULTS FPL ameliorated lipid accumulation and inflammation levels in rats. Meanwhile, the levels of ethanol dehydrogenase, acetaldehyde dehydrogenase, and cytochrome P4502E1 were elevated by FPL treatment. It was observed that the levels of catalase, superoxide dismutase, and glutathione peroxidase were elevated, and the expression of nuclear transcriptional factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 genes and proteins were increased by FPL treatment, demonstrating that the Nrf2-mediated signal pathway was activated. Furthermore, FPL restored the composition of the gut microbiota with an increase in the abundances of Firmicutes and Lactobacillus and a decrease in the abundances of Bacteroidota and Akkermansia. Additionally, a strong correlation was found between the gut microbiota and the antioxidant parameters. CONCLUSION The results indicate that FPL possesses an excellent protective effect in alcoholic liver injury. Our findings are beneficial to the development of hepatoprotective nutraceuticals for alcoholics. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Wenjun Zhao
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Dong Peng
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Weijie Li
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Suiying Chen
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Bing Liu
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Pingxi Huang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Junsong Wu
- Guangzhou Songyuan Agricultural Technology Co., Ltd, Guangzhou, China
| | - Bing Du
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Pan Li
- College of Food Science, South China Agricultural University, Guangzhou, China
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3
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Spatiotemporal kinetics of the SRP pathway in live E. coli cells. Proc Natl Acad Sci U S A 2022; 119:e2204038119. [PMID: 36095178 PMCID: PMC9499511 DOI: 10.1073/pnas.2204038119] [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: 11/18/2022] Open
Abstract
Mechanistic details of the signal recognition particle (SRP)-mediated insertion of membrane proteins have been described from decades of in vitro biochemical studies. However, the dynamics of the pathway inside the living cell remain obscure. By combining in vivo single-molecule tracking with numerical modeling and simulated microscopy, we have constructed a quantitative reaction-diffusion model of the SRP cycle. Our results suggest that the SRP-ribosome complex finds its target, the membrane-bound translocon, through a combination of three-dimensional (3D) and 2D diffusional search, together taking on average 750 ms. During this time, the nascent peptide is expected to be elongated only 12 or 13 amino acids, which explains why, in Escherichia coli, no translation arrest is needed to prevent incorrect folding of the polypeptide in the cytosol. We also found that a remarkably high proportion (75%) of SRP bindings to ribosomes occur in the cytosol, suggesting that the majority of target ribosomes bind SRP before reaching the membrane. In combination with the average SRP cycling time, 2.2 s, this result further shows that the SRP pathway is capable of targeting all substrate ribosomes to translocons.
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Selective recruitment of stress-responsive mRNAs to ribosomes for translation by acetylated protein S1 during nutrient stress in Escherichia coli. Commun Biol 2022; 5:892. [PMID: 36050442 PMCID: PMC9437053 DOI: 10.1038/s42003-022-03853-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 08/16/2022] [Indexed: 12/02/2022] Open
Abstract
The chemical modification of ribosomes plays an important regulatory role in cellular translation adaptation in response to environmental stresses. Nevertheless, how the modified ribosome reprograms the translation machinery for the preferential expression of the specific mRNAs encoding stress-responsive proteins to stress remains poorly understood. Here, we find that AcP-induced acetylation of K411 and K464 in ribosomal protein S1 during carbon-nitrogen imbalance, which in turn impacts its binding with distinct mRNAs. S1 acetylation shows differential selectivity for recruiting subsets of mRNAs to ribosomes. Using the RNC-Seq method, we find that mimic acetylated S1 prefers transcripts related with the formation of flagella/biofilms, two-component systems, nitrogen assimilation, amino acid degradation, and lipopolysaccharide biosynthesis, whereas inhibits the translation of mRNAs involved in amino acid biosynthesis and most ribosomal proteins. Importantly, further characterization of S1-binding site (SBS) sequences of mRNAs with different translation efficiencies indicated that the presence of a conserved motif allows coordinated regulation of S1 acetylation-driven translation reprogramming for cell survival during nitrogen starvation. These findings expand the repertoire of ribosome heterogeneity to the acetylation level of S1 at specific sites and its role in the ribosome-mediated regulation of gene expression as a cellular response at the translational level to stress. RNA molecular chaperone S1 is acetylated and selectively recruits stress-responsive mRNAs to the ribosome during nitrogen starvation in E. coli, revealing a translation regulation mechanism for nutrient stress adaptation.
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A Neural Networks Approach for the Analysis of Reproducible Ribo–Seq Profiles. ALGORITHMS 2022. [DOI: 10.3390/a15080274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In recent years, the Ribosome profiling technique (Ribo–seq) has emerged as a powerful method for globally monitoring the translation process in vivo at single nucleotide resolution. Based on deep sequencing of mRNA fragments, Ribo–seq allows to obtain profiles that reflect the time spent by ribosomes in translating each part of an open reading frame. Unfortunately, the profiles produced by this method can vary significantly in different experimental setups, being characterized by a poor reproducibility. To address this problem, we have employed a statistical method for the identification of highly reproducible Ribo–seq profiles, which was tested on a set of E. coli genes. State-of-the-art artificial neural network models have been used to validate the quality of the produced sequences. Moreover, new insights into the dynamics of ribosome translation have been provided through a statistical analysis on the obtained sequences.
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Shen LL, Waheed A, Wang YP, Nkurikiyimfura O, Wang ZH, Yang LN, Zhan J. Mitochondrial Genome Contributes to the Thermal Adaptation of the Oomycete Phytophthora infestans. Front Microbiol 2022; 13:928464. [PMID: 35836411 PMCID: PMC9273971 DOI: 10.3389/fmicb.2022.928464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
As a vital element of climate change, elevated temperatures resulting from global warming present new challenges to natural and agricultural sustainability, such as ecological disease management. Mitochondria regulate the energy production of cells in responding to environmental fluctuation, but studying their contribution to the thermal adaptation of species is limited. This knowledge is needed to predict future disease epidemiology for ecology conservation and food security. Spatial distributions of the mitochondrial genome (mtDNA) in 405 Phytophthora infestans isolates originating from 15 locations were characterized. The contribution of MtDNA to thermal adaptation was evaluated by comparative analysis of mtDNA frequency and intrinsic growth rate, relative population differentiation in nuclear and mtDNA, and associations of mtDNA distribution with local geography climate conditions. Significant variation in frequency, intrinsic growth rate, and spatial distribution was detected in mtDNA. Population differentiation in mtDNA was significantly higher than that in the nuclear genome, and spatial distribution of mtDNA was strongly associated with local climatic conditions and geographic parameters, particularly air temperature, suggesting natural selection caused by a local temperature is the main driver of the adaptation. Dominant mtDNA grew faster than the less frequent mtDNA. Our results provide useful insights into the evolution of pathogens under global warming. Given its important role in biological functions and adaptation to local air temperature, mtDNA intervention has become an increasing necessity for future disease management. To secure ecological integrity and food production under global warming, a synergistic study on the interactive effect of changing temperature on various components of biological and ecological functions of mitochondria in an evolutionary frame is urgently needed.
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Affiliation(s)
- Lin-Lin Shen
- Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Abdul Waheed
- Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Yan-Ping Wang
- Sichuan Provincial Key Laboratory for Development and Utilization of Characteristic Horticultural Biological Resources, Chengdu Normal University, Chengdu, China
| | - Oswald Nkurikiyimfura
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zong-Hua Wang
- Institute of Oceanography, Minjiang University, Fuzhou, China
| | - Li-Na Yang
- Institute of Oceanography, Minjiang University, Fuzhou, China
- *Correspondence: Li-Na Yang
| | - Jiasui Zhan
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Synergistic Regulation of Transcription and Translation in Escherichia coli Revealed by Codirectional Increases in mRNA Concentration and Translation Efficiency. Microbiol Spectr 2022; 10:e0204121. [PMID: 35138139 PMCID: PMC8826937 DOI: 10.1128/spectrum.02041-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Translational regulation was investigated at the genome-scale in Escherichia coli cells. Using the polysome profiling method, the ribosome occupancy (RO) and ribosome density (RD) of different mRNA copies were determined for several hundred mRNAs during the exponential- and stationary-phases, providing the most complete characterization of such regulation in E. coli. Although for most genes, nearly all mRNAs (>90%) were undergoing translation, they were loaded with far fewer than the theoretical maximum number of ribosomes, suggesting translation limitation at the initiation step. Multiple linear regression was used to identify key intrinsic factors involved in the genome-wide regulation of RO and RD (i.e., open reading frame GC%, protein function, and localization). Unexpectedly, mRNA concentration, a factor that depends on cell physiology, was predicted to positively regulate RO and RD during the exponential- and stationary-phases. Using a set of selected genes controlled by an inducible promoter, we confirmed that increasing the mRNA concentration upon transcription induction led to increases in both RO and ribosome load. The fact that this relationship between mRNA concentration and translation parameters was also effective when E. coli cells naturally adapted to carbon source changes demonstrates its physiological relevance. This work demonstrated that translation regulation is positively controlled by transcript availability. This new mechanism contributed to the codirectional regulation of transcription and translation with synergistic effects on gene expression and provided a systemic understanding of E. coli cell function. IMPORTANCE The process of gene expression is divided into translation and transcription. Considerable efforts have been made in bacteria to characterize the mechanisms underlying translational regulation and identify the regulatory factors for particular mRNAs. However, to understand bacterial physiology and adaptation, it is important to elucidate genome-wide translational regulation and examine its coordination with transcriptional regulation. Here, we provided a genome-wide picture of translational regulation in Escherichia coli. For most genes, nearly all mRNA copies were found to undergo translation but were loaded with a low number of ribosomes. We showed that mRNA concentration had a positive effect on translation regulation, linking translational regulation to transcriptional regulation as well as to cell physiology and growth conditions. The codirectional regulation of transcription and translation had synergistic effects on gene expression, contributing to E. coli cell function optimization. This finding could be used in biotechnology to optimize strategies for recombinant protein synthesis.
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Different Regulatory Modes of Synechocystis sp. PCC 6803 in Response to Photosynthesis Inhibitory Conditions. mSystems 2021; 6:e0094321. [PMID: 34874777 PMCID: PMC8651088 DOI: 10.1128/msystems.00943-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Cyanobacteria are promising industrial platforms owing to their ability to produce diverse natural secondary metabolites and nonnative value-added biochemicals from CO2 and light. To fully utilize their industrial potency, it is critical to understand their photosynthetic efficiency under various environmental conditions. In this study, we elucidated the inhibitory mechanisms of photosynthesis under high-light and low-temperature stress conditions in the model cyanobacterium Synechocystis sp. PCC 6803. Under each stress condition, the transcript abundance and translation efficiency were measured using transcriptome sequencing (RNA-seq) and ribosome profiling, and the genome-wide transcription unit architecture was constructed by data integration of transcription start sites and transcript 3′-end positions obtained from differential RNA-seq and sequencing of 3′-ends (Term-seq), respectively. Our results suggested that the mode of photosynthesis inhibition differed between the two stress conditions; high light stress induced photodamage responses, while low temperature stress impaired the translation efficiency of photosynthesis-associated genes. In particular, poor translation of photosystem I resulted from ribosome stalling at the untranslated regions, affecting the overall photosynthetic yield under low temperature stress. Our comprehensive multiomics analysis with transcription unit architecture provides foundational information on photosynthesis for future industrial strain development. IMPORTANCE Cyanobacteria are a compelling biochemical production platform for their ability to propagate using light and atmospheric CO2 via photosynthesis. However, the engineering of strains is hampered by limited understanding of photosynthesis under diverse environmental conditions such as high-light and low-temperature stresses. Herein, we decipher the transcriptomic and translatomic responses of the photosynthetic efficiency to stress conditions using the integrative analysis of multiomic data generated by RNA-seq and ribosome profiling, respectively. Through the generated massive data, along with the guide of the genome-wide transcription unit architecture constructed by transcription start sites and transcript 3′-end positions, we identified the factors affecting photosynthesis at transcription, posttranscription, and translation levels. Importantly, the high-light stress induces photodamage responses, and the low-temperature stress cripples the translation efficiency of photosynthesis-associated genes. The resulting insights provide pivotal information for future cyanobacterial cell factories powered by the engineering toward robust photosynthesis ability.
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9
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Shimizu K, Matsuoka Y. Feedback regulation and coordination of the main metabolism for bacterial growth and metabolic engineering for amino acid fermentation. Biotechnol Adv 2021; 55:107887. [PMID: 34921951 DOI: 10.1016/j.biotechadv.2021.107887] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 12/05/2021] [Accepted: 12/09/2021] [Indexed: 12/28/2022]
Abstract
Living organisms such as bacteria are often exposed to continuous changes in the nutrient availability in nature. Therefore, bacteria must constantly monitor the environmental condition, and adjust the metabolism quickly adapting to the change in the growth condition. For this, bacteria must orchestrate (coordinate and integrate) the complex and dynamically changing information on the environmental condition. In particular, the central carbon metabolism (CCM), monomer synthesis, and macromolecular synthesis must be coordinately regulated for the efficient growth. It is a grand challenge in bioscience, biotechnology, and synthetic biology to understand how living organisms coordinate the metabolic regulation systems. Here, we consider the integrated sensing of carbon sources by the phosphotransferase system (PTS), and the feed-forward/feedback regulation systems incorporated in the CCM in relation to the pool sizes of flux-sensing metabolites and αketoacids. We also consider the metabolic regulation of amino acid biosynthesis (as well as purine and pyrimidine biosyntheses) paying attention to the feedback control systems consisting of (fast) enzyme level regulation with (slow) transcriptional regulation. The metabolic engineering for the efficient amino acid production by bacteria such as Escherichia coli and Corynebacterium glutamicum is also discussed (in relation to the regulation mechanisms). The amino acid synthesis is important for determining the rate of ribosome biosynthesis. Thus, the growth rate control (growth law) is further discussed on the relationship between (p)ppGpp level and the ribosomal protein synthesis.
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Affiliation(s)
- Kazuyuki Shimizu
- Kyushu institute of Technology, Iizuka, Fukuoka 820-8502, Japan; Institute of Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0017, Japan.
| | - Yu Matsuoka
- Department of Fisheries Distribution and Management, National Fisheries University, Shimonoseki, Yamaguchi 759-6595, Japan
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10
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Abstract
Bacteria often encounter temperature fluctuations in their natural habitats and must adapt to survive. The molecular response of bacteria to sudden temperature upshift or downshift is termed the heat shock response (HSR) or the cold shock response (CSR), respectively. Unlike the HSR, which activates a dedicated transcription factor that predominantly copes with heat-induced protein folding stress, the CSR is mediated by a diverse set of inputs. This review provides a picture of our current understanding of the CSR across bacteria. The fundamental aspects of CSR involved in sensing and adapting to temperature drop, including regulation of membrane fluidity, protein folding, DNA topology, RNA metabolism, and protein translation, are discussed. Special emphasis is placed on recent findings of a CSR circuitry in Escherichia coli mediated by cold shock family proteins and RNase R that monitors and modulates messenger RNA structure to facilitate global translation recovery during acclimation. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yan Zhang
- Department of Microbiology and Immunology, University of California, San Francisco, California 94158, USA;
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California, San Francisco, California 94158, USA; .,Department of Cell and Tissue Biology, University of California, San Francisco, California 94158, USA.,California Institute of Quantitative Biology, University of California, San Francisco, California 94158, USA
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11
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Ho JJD, Man JHS, Schatz JH, Marsden PA. Translational remodeling by RNA-binding proteins and noncoding RNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1647. [PMID: 33694288 DOI: 10.1002/wrna.1647] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 12/14/2022]
Abstract
Responsible for generating the proteome that controls phenotype, translation is the ultimate convergence point for myriad upstream signals that influence gene expression. System-wide adaptive translational reprogramming has recently emerged as a pillar of cellular adaptation. As classic regulators of mRNA stability and translation efficiency, foundational studies established the concept of collaboration and competition between RNA-binding proteins (RBPs) and noncoding RNAs (ncRNAs) on individual mRNAs. Fresh conceptual innovations now highlight stress-activated, evolutionarily conserved RBP networks and ncRNAs that increase the translation efficiency of populations of transcripts encoding proteins that participate in a common cellular process. The discovery of post-transcriptional functions for long noncoding RNAs (lncRNAs) was particularly intriguing given their cell-type-specificity and historical definition as nuclear-functioning epigenetic regulators. The convergence of RBPs, lncRNAs, and microRNAs on functionally related mRNAs to enable adaptive protein synthesis is a newer biological paradigm that highlights their role as "translatome (protein output) remodelers" and reinvigorates the paradigm of "RNA operons." Together, these concepts modernize our understanding of cellular stress adaptation and strategies for therapeutic development. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications Translation > Translation Regulation Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Affiliation(s)
- J J David Ho
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Jeffrey H S Man
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Respirology, University Health Network, Latner Thoracic Research Laboratories, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan H Schatz
- Sylvester Comprehensive Cancer Center, Miller School of Medicine, University of Miami, Miami, Florida, USA.,Division of Hematology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Philip A Marsden
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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12
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Comparative transcriptomic study of Escherichia coli O157:H7 in response to ohmic heating and conventional heating. Food Res Int 2021; 140:109989. [PMID: 33648224 DOI: 10.1016/j.foodres.2020.109989] [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: 12/22/2019] [Revised: 05/29/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
In this study, the high-throughput Illumina HiSeq 2000 mRNA sequencing technique was used to investigate the transcriptome response of Escherichia coli O157:H7 exposed to ohmic heating (OH) and water bath heating (WB). Compared to untreated samples, a total of 293, 516, and 498 genes showed differential expression after HVOH (high voltage short time ohmic heating), LVOH (low voltage long time ohmic heating), and WB, respectively. Therefore, LVOH had the potential to cause comparable effects on the transcriptome of E. coli O157:H7 as compared to WB, but not HVOH. These results indicated that additional non-thermal effects were not reflected on transcriptome of E. coli O157:H7 using both HVOH and LVOH, in particular the HVOH. Most of differentially expressed genes involved in information storage and processing, and cellular processes and signaling showed up-regulation whereas most of genes related to the metabolism were down-regulated after HVOH, LVOH, and WB. In addition, more attention needs to be paid to the up-regulation of a large number of virulence genes, which might increase the ability of surviving E. coli O157:H7 to infect host cells after HVOH, LVOH, and WB. This transcriptomic study on the response of E. coli O157:H7 to OH protomes the understanding of inactivation mechanism of OH on the molecular level and opens the door to future studies for OH.
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Combinatorial strategy towards the efficient expression of lipoxygenase in Escherichia coli at elevated temperatures. Appl Microbiol Biotechnol 2020; 104:10047-10057. [PMID: 33037915 DOI: 10.1007/s00253-020-10941-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/31/2020] [Accepted: 10/04/2020] [Indexed: 02/07/2023]
Abstract
Lipoxygenases (LOXs) are a family of non-heme iron oxidoreductases, which catalyze the addition of oxygen into polyunsaturated fatty acids. They have applications in the food and medical industries. In most studies, the soluble expression of LOXs in microbes requires low temperature (< 20 °C), which increases the cost and fermentation time. Achievement of soluble expression in elevated temperatures (> 30 °C) would shorten the production phase, leading to cost-efficient industrial applications. In this study, a combinatorial strategy was used to enhance the expression of soluble LOXs, comprising plasmid stability systems plus optimized carbon source used for auto-induction expression. Plasmid stability analysis suggested that both active partition systems and plasmid-dependent systems were essential for plasmid stability. Among them, the parBCA in it resulted in the enzyme activity increasing by a factor of 2 (498 ± 13 units per gram dry cell weight (U/g-DCW) after 6-h induction). Furthermore, the optimized carbon source, composed of glucose, lactose, and glycerol, could be used as an auto-induction expression medium and effectively improve the total and soluble expression of LOX, which resulted in the soluble expression of LOX increased by 7 times. Finally, the soluble expression of LOX was 11 times higher with a combinatorial strategy that included both optimized plasmid partition and auto-induction medium. Our work provides a broad, generalizable, and combinatorial strategy for the efficient production of heterologous proteins at elevated temperatures in the E. coli system. KEY POINTS : • Soluble expression of lipoxygenase at 30 °C or higher temperatures is industrially beneficial. • Strategies comprise plasmid partition and optimized auto-induction medium with glucose, lactose, and glycerol as carbon source. • Combinatorial strategy further improved LOX soluble expression at 30 °C and 37 °C.
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Tollerson R, Ibba M. Translational regulation of environmental adaptation in bacteria. J Biol Chem 2020; 295:10434-10445. [PMID: 32518156 DOI: 10.1074/jbc.rev120.012742] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/08/2020] [Indexed: 01/26/2023] Open
Abstract
Bacteria must rapidly respond to both intracellular and environmental changes to survive. One critical mechanism to rapidly detect and adapt to changes in environmental conditions is control of gene expression at the level of protein synthesis. At each of the three major steps of translation-initiation, elongation, and termination-cells use stimuli to tune translation rate and cellular protein concentrations. For example, changes in nutrient concentrations in the cell can lead to translational responses involving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthesis of alarmones, which drastically alter cell physiology. Moreover, the cell can fine-tune the levels of specific protein products using programmed ribosome pausing or inducing frameshifting. Recent studies have improved understanding and revealed greater complexity regarding long-standing paradigms describing key regulatory steps of translation such as start-site selection and the coupling of transcription and translation. In this review, we describe how bacteria regulate their gene expression at the three translational steps and discuss how translation is used to detect and respond to changes in the cellular environment. Finally, we appraise the costs and benefits of regulation at the translational level in bacteria.
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Affiliation(s)
- Rodney Tollerson
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
| | - Michael Ibba
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
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15
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Nizkorodova A, Suvorova M, Zhigailov A, Iskakov B. The Effect of Translation Promoting Site (TPS) on Protein Expression in E. coli Cells. Mol Biotechnol 2020; 62:326-334. [PMID: 32227298 DOI: 10.1007/s12033-020-00251-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The study of translation initiation in prokaryotes assumes that there should be a mechanism different from the canonical model, which postulates the formation of the pre-initiation complex through the interaction of the Shine-Dalgarno sequence (SD) at the 5'-end of mRNA and the anti-Shine-Dalgarno site at the 3'-end of 16S rRNA. In this paper we've studied the effect of TPS (Translation-initiation Promoting Site) on β-glucuronidase expression in E. coli cells at different cultivation temperatures. The examined leader sequences were cloned into the pET23c plasmid upstream the β-glucuronidase gene; protein expression was performed in E. coli BL21 (DE3) cells. β-glucuronidase activity was measured in bacterial cell extracts via paranitrophenyl b-D-glucuronide assay. The quantity of expressed protein was measured by Western blotting with following densitometry. It was shown that TPS increases the level of protein expression at stressful conditions (10 °C and 44 °C) 5-8 times compared to control. The combination of TPS and SD sites in the 5'-leader sequence of the mRNA created an enhancer that increased the expression level 2-3.6 times compared to a single SD-sequence. Based on the obtained data and the computer modeling of interaction between 16S rRNA and TPS, we proposed an alternative variation of prokaryotic translation initiation.
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Affiliation(s)
- Anna Nizkorodova
- Laboratory of Protein and Nucleic Acids, M.Aythozhin Institute of Molecular Biology and Biochemistry, Dosmuhamedov St. 80, 050012, Almaty, Kazakhstan.
| | - Maria Suvorova
- Department of Biodiversity, Biological Faculty, Al-Faraby State National University, Almaty, Kazakhstan
| | - Andrey Zhigailov
- Laboratory of Protein and Nucleic Acids, M.Aythozhin Institute of Molecular Biology and Biochemistry, Dosmuhamedov St. 80, 050012, Almaty, Kazakhstan
| | - Bulat Iskakov
- Laboratory of Protein and Nucleic Acids, M.Aythozhin Institute of Molecular Biology and Biochemistry, Dosmuhamedov St. 80, 050012, Almaty, Kazakhstan
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16
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Engineering Biology to Construct Microbial Chassis for the Production of Difficult-to-Express Proteins. Int J Mol Sci 2020; 21:ijms21030990. [PMID: 32024292 PMCID: PMC7037952 DOI: 10.3390/ijms21030990] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/28/2020] [Accepted: 01/31/2020] [Indexed: 12/12/2022] Open
Abstract
A large proportion of the recombinant proteins manufactured today rely on microbe-based expression systems owing to their relatively simple and cost-effective production schemes. However, several issues in microbial protein expression, including formation of insoluble aggregates, low protein yield, and cell death are still highly recursive and tricky to optimize. These obstacles are usually rooted in the metabolic capacity of the expression host, limitation of cellular translational machineries, or genetic instability. To this end, several microbial strains having precisely designed genomes have been suggested as a way around the recurrent problems in recombinant protein expression. Already, a growing number of prokaryotic chassis strains have been genome-streamlined to attain superior cellular fitness, recombinant protein yield, and stability of the exogenous expression pathways. In this review, we outline challenges associated with heterologous protein expression, some examples of microbial chassis engineered for the production of recombinant proteins, and emerging tools to optimize the expression of heterologous proteins. In particular, we discuss the synthetic biology approaches to design and build and test genome-reduced microbial chassis that carry desirable characteristics for heterologous protein expression.
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17
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Deter HS, Abualrahi AH, Jadhav P, Schweer EK, Ogle CT, Butzin NC. Proteolytic Queues at ClpXP Increase Antibiotic Tolerance. ACS Synth Biol 2020; 9:95-103. [PMID: 31860281 DOI: 10.1021/acssynbio.9b00358] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Antibiotic tolerance is a widespread phenomenon that renders antibiotic treatments less effective and facilitates antibiotic resistance. Here we explore the role of proteases in antibiotic tolerance, short-term population survival of antibiotics, using queueing theory (i.e., the study of waiting lines), computational models, and a synthetic biology approach. Proteases are key cellular components that degrade proteins and play an important role in a multidrug tolerant subpopulation of cells, called persisters. We found that queueing at the protease ClpXP increases antibiotic tolerance ∼80 and ∼60 fold in an E. coli population treated with ampicillin and ciprofloxacin, respectively. There does not appear to be an effect on antibiotic persistence, which we distinguish from tolerance based on population decay. These results demonstrate that proteolytic queueing is a practical method to probe proteolytic activity in bacterial tolerance and related genes, while limiting the unintended consequences frequently caused by gene knockout and overexpression.
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Affiliation(s)
- Heather S Deter
- Department of Biology and Microbiology , South Dakota State University , Brookings , South Dakota 57006 , United States
| | - Alawiah H Abualrahi
- Department of Biology and Microbiology , South Dakota State University , Brookings , South Dakota 57006 , United States
| | - Prajakta Jadhav
- Department of Biology and Microbiology , South Dakota State University , Brookings , South Dakota 57006 , United States
| | - Elise K Schweer
- Department of Biology and Microbiology , South Dakota State University , Brookings , South Dakota 57006 , United States
| | | | - Nicholas C Butzin
- Department of Biology and Microbiology , South Dakota State University , Brookings , South Dakota 57006 , United States
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18
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Moreira MH, Barros GC, Requião RD, Rossetto S, Domitrovic T, Palhano FL. From reporters to endogenous genes: the impact of the first five codons on translation efficiency in Escherichia coli. RNA Biol 2019; 16:1806-1816. [PMID: 31470761 PMCID: PMC6844562 DOI: 10.1080/15476286.2019.1661213] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 08/23/2019] [Indexed: 12/29/2022] Open
Abstract
Translation initiation is a critical step in the regulation of protein synthesis, and it is subjected to different control mechanisms, such as 5' UTR secondary structure and initiation codon context, that can influence the rates at which initiation and consequentially translation occur. For some genes, translation elongation also affects the rate of protein synthesis. With a GFP library containing nearly all possible combinations of nucleotides from the 3rd to the 5th codon positions in the protein coding region of the mRNA, it was previously demonstrated that some nucleotide combinations increased GFP expression up to four orders of magnitude. While it is clear that the codon region from positions 3 to 5 can influence protein expression levels of artificial constructs, its impact on endogenous proteins is still unknown. Through bioinformatics analysis, we identified the nucleotide combinations of the GFP library in Escherichia coli genes and examined the correlation between the expected levels of translation according to the GFP data with the experimental measures of protein expression. We observed that E. coli genes were enriched with the nucleotide compositions that enhanced protein expression in the GFP library, but surprisingly, it seemed to affect the translation efficiency only marginally. Nevertheless, our data indicate that different enterobacteria present similar nucleotide composition enrichment as E. coli, suggesting an evolutionary pressure towards the conservation of short translational enhancer sequences.
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Affiliation(s)
- Mariana H. Moreira
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Géssica C. Barros
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rodrigo D. Requião
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Silvana Rossetto
- Departamento de Ciência da Computação, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tatiana Domitrovic
- Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernando L. Palhano
- Programa de Biologia Estrutural, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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19
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Bucca G, Pothi R, Hesketh A, Möller-Levet C, Hodgson DA, Laing EE, Stewart GR, Smith CP. Translational control plays an important role in the adaptive heat-shock response of Streptomyces coelicolor. Nucleic Acids Res 2019; 46:5692-5703. [PMID: 29746664 PMCID: PMC6009599 DOI: 10.1093/nar/gky335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/18/2018] [Indexed: 12/29/2022] Open
Abstract
Stress-induced adaptations require multiple levels of regulation in all organisms to repair cellular damage. In the present study we evaluated the genome-wide transcriptional and translational changes following heat stress exposure in the soil-dwelling model actinomycete bacterium, Streptomyces coelicolor. The combined analysis revealed an unprecedented level of translational control of gene expression, deduced through polysome profiling, in addition to transcriptional changes. Our data show little correlation between the transcriptome and ‘translatome’; while an obvious downward trend in genome wide transcription was observed, polysome associated transcripts following heat-shock showed an opposite upward trend. A handful of key protein players, including the major molecular chaperones and proteases were highly induced at both the transcriptional and translational level following heat-shock, a phenomenon known as ‘potentiation’. Many other transcripts encoding cold-shock proteins, ABC-transporter systems, multiple transcription factors were more highly polysome-associated following heat stress; interestingly, these protein families were not induced at the transcriptional level and therefore were not previously identified as part of the stress response. Thus, stress coping mechanisms at the level of gene expression in this bacterium go well beyond the induction of a relatively small number of molecular chaperones and proteases in order to ensure cellular survival at non-physiological temperatures.
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Affiliation(s)
- Giselda Bucca
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - Radhika Pothi
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Andrew Hesketh
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - Carla Möller-Levet
- Bioinformatics facility, Faculty of Health and Medical Sciences, University of Surrey, UK
| | | | - Emma E Laing
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Graham R Stewart
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, UK
| | - Colin P Smith
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
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20
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Halpin JC, Jangi R, Street TO. Multimapping confounds ribosome profiling analysis: A case-study of the Hsp90 molecular chaperone. Proteins 2019; 88:57-68. [PMID: 31254414 DOI: 10.1002/prot.25766] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/17/2019] [Accepted: 06/25/2019] [Indexed: 11/11/2022]
Abstract
Ribosome profiling (Ribo-seq) can potentially provide detailed information about ribosome position on transcripts and estimates of protein translation levels in vivo. Hsp90 chaperones, which play a critical role in stress tolerance, have characteristic patterns of differential expression under nonstressed and heat shock conditions. By analyzing published Ribo-seq data for the Hsp90 chaperones in S. cerevisiae, we find wide-ranging artifacts originating from "multimapping" reads (reads that cannot be uniquely assigned to one position), which constitute ~25% of typical S. cerevisiae Ribo-seq datasets and ~80% of the reads from HEK293 cells. Estimates of Hsp90 protein production as determined by Ribo-seq are reproducible but not robust, with inferred expression levels that can change 10-fold depending on how multimapping reads are processed. The differential expression of Hsp90 chaperones under nonstressed and heat shock conditions creates artificial peaks and valleys in their ribosome profiles that give a false impression of regulated translational pausing. Indeed, we find that multimapping can even create an appearance of reproducibility to the shape of the Hsp90 ribosome profiles from biological replicates. Adding further complexity, this artificial reproducibility is dependent on the computational method used to construct the ribosome profile. Given the ubiquity of multimapping reads in Ribo-seq experiments and the complexity of artifacts associated with multimapping, we developed a publicly available computational tool to identify transcripts most at risk for multimapping artifacts. In doing so, we identify biological pathways that are enriched in multimapping transcripts, meaning that particular biological pathways will be highly susceptible to multimapping artifacts.
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Affiliation(s)
- Jackson C Halpin
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts
| | - Radhika Jangi
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts
| | - Timothy O Street
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts
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21
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Elongation factor P is required to maintain proteome homeostasis at high growth rate. Proc Natl Acad Sci U S A 2018; 115:11072-11077. [PMID: 30297417 DOI: 10.1073/pnas.1812025115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Elongation factor P (EF-P) is a universally conserved translation factor that alleviates ribosome pausing at polyproline (PPX) motifs by facilitating peptide bond formation. In the absence of EF-P, PPX peptide bond formation can limit translation rate, leading to pleotropic phenotypes including slowed growth, increased antibiotic sensitivity, and loss of virulence. In this study, we observe that many of these phenotypes are dependent on growth rate. Limiting growth rate suppresses a variety of detrimental phenotypes associated with ribosome pausing at PPX motifs in the absence of EF-P. Polysome levels are also similar to wild-type under slow growth conditions, consistent with global changes in ribosome queuing in cells without EF-P when growth rate is decreased. Inversely, under high protein synthesis demands, we observe that Escherichia coli lacking EF-P have reduced fitness. Our data demonstrate that EF-P-mediated relief of ribosome queuing is required to maintain proteome homeostasis under conditions of high translational demands.
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