151
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Abstract
Since Jacques Monod's foundational work in the 1940s, investigators studying bacterial physiology have largely (but not exclusively) focused on the exponential phase of bacterial cultures, which is characterized by rapid growth and high biosynthesis activity in the presence of excess nutrients. However, this is not the predominant state of bacterial life. In nature, most bacteria experience nutrient limitation most of the time. In fact, investigators even prior to Monod had identified other aspects of bacterial growth, including what is now known as the stationary phase, when nutrients become limiting. This review will discuss how bacteria transition to growth arrest in response to nutrient limitation through changes in transcription, translation, and metabolism. We will then examine how these changes facilitate survival during potentially extended periods of nutrient limitation, with particular attention to the metabolic strategies that underpin bacterial longevity in this state.
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Affiliation(s)
- Jonathan Dworkin
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Caroline S Harwood
- Department of Microbiology, University of Washington, Seattle, Washington, USA;
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152
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Chang S, Thrall ES, Laureti L, Piatt SC, Pagès V, Loparo JJ. Compartmentalization of the replication fork by single-stranded DNA-binding protein regulates translesion synthesis. Nat Struct Mol Biol 2022; 29:932-941. [PMID: 36127468 PMCID: PMC9509481 DOI: 10.1038/s41594-022-00827-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/28/2022] [Indexed: 11/09/2022]
Abstract
Processivity clamps tether DNA polymerases to DNA, allowing their access to the primer-template junction. In addition to DNA replication, DNA polymerases also participate in various genome maintenance activities, including translesion synthesis (TLS). However, owing to the error-prone nature of TLS polymerases, their association with clamps must be tightly regulated. Here we show that fork-associated ssDNA-binding protein (SSB) selectively enriches the bacterial TLS polymerase Pol IV at stalled replication forks. This enrichment enables Pol IV to associate with the processivity clamp and is required for TLS on both the leading and lagging strands. In contrast, clamp-interacting proteins (CLIPs) lacking SSB binding are spatially segregated from the replication fork, minimally interfering with Pol IV-mediated TLS. We propose that stalling-dependent structural changes within clusters of fork-associated SSB establish hierarchical access to the processivity clamp. This mechanism prioritizes a subset of CLIPs with SSB-binding activity and facilitates their exchange at the replication fork.
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Affiliation(s)
- Seungwoo Chang
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Elizabeth S Thrall
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Department of Chemistry, Fordham University, New York City, NY, USA
| | - Luisa Laureti
- CRCM (Cancer Research Center of Marseille): Team DNA Damage and Genome Instability, Aix-Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, Marseille, France
| | - Sadie C Piatt
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Harvard Graduate Program in Biophysics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Vincent Pagès
- CRCM (Cancer Research Center of Marseille): Team DNA Damage and Genome Instability, Aix-Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, Marseille, France
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
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153
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Wang Q, Lin J. Environment-specificity and universality of the microbial growth law. Commun Biol 2022; 5:891. [PMID: 36045217 PMCID: PMC9433384 DOI: 10.1038/s42003-022-03815-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 08/08/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractAs the nutrient quality changes, the fractions of ribosomal proteins in the proteome are usually positively correlated with the growth rates due to the auto-catalytic nature of ribosomes. While this growth law is observed across multiple organisms, the relation between the ribosome fraction and growth rate is often more complex than linear, beyond models assuming a constant translation speed. Here, we propose a general framework of protein synthesis considering heterogeneous translation speeds and protein degradations. We demonstrate that the growth law curves are generally environment-specific, e.g., depending on the correlation between the translation speeds and ribosome allocations among proteins. Our predictions of ribosome fractions agree quantitatively with data of Saccharomyces cerevisiae. Interestingly, we find that the growth law curve of Escherichia coli nevertheless appears universal, which we prove must exhibit an upward bending in slow-growth conditions, in agreement with experiments. Our work provides insights on the connection between the heterogeneity among genes and the environment-specificity of cell behaviors.
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154
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Real-time detection of response regulator phosphorylation dynamics in live bacteria. Proc Natl Acad Sci U S A 2022; 119:e2201204119. [PMID: 35994658 PMCID: PMC9436347 DOI: 10.1073/pnas.2201204119] [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
Bacteria utilize two-component system (TCS) signal transduction pathways to sense and adapt to changing environments. In a typical TCS, a stimulus induces a sensor histidine kinase (SHK) to phosphorylate a response regulator (RR), which then dimerizes and activates a transcriptional response. Here, we demonstrate that oligomerization-dependent depolarization of excitation light by fused mNeonGreen fluorescent protein probes enables real-time monitoring of RR dimerization dynamics in live bacteria. Using inducible promoters to independently express SHKs and RRs, we detect RR dimerization within seconds of stimulus addition in several model pathways. We go on to combine experiments with mathematical modeling to reveal that TCS phosphosignaling accelerates with SHK expression but decelerates with RR expression and SHK phosphatase activity. We further observe pulsatile activation of the SHK NarX in response to addition and depletion of the extracellular electron acceptor nitrate when the corresponding TCS is expressed from both inducible systems and the native chromosomal operon. Finally, we combine our method with polarized light microscopy to enable single-cell measurements of RR dimerization under changing stimulus conditions. Direct in vivo characterization of RR oligomerization dynamics should enable insights into the regulation of bacterial physiology.
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155
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Schink SJ, Gough Z, Biselli E, Huiman MG, Chang YF, Basan M, Gerland U. MetA is a "thermal fuse" that inhibits growth and protects Escherichia coli at elevated temperatures. Cell Rep 2022; 40:111290. [PMID: 36044860 PMCID: PMC10477958 DOI: 10.1016/j.celrep.2022.111290] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/10/2022] [Accepted: 08/10/2022] [Indexed: 11/15/2022] Open
Abstract
Adaptive stress resistance in microbes is mostly attributed to the expression of stress response genes, including heat-shock proteins. Here, we report a response of E. coli to heat stress caused by degradation of an enzyme in the methionine biosynthesis pathway (MetA). While MetA degradation can inhibit growth, which by itself is detrimental for fitness, we show that it directly benefits survival at temperatures exceeding 50°C, increasing survival chances by more than 1,000-fold. Using both experiments and mathematical modeling, we show quantitatively how protein expression, degradation rates, and environmental stressors cause long-term growth inhibition in otherwise habitable conditions. Because growth inhibition can be abolished with simple mutations, namely point mutations of MetA and protease knockouts, we interpret the breakdown of methionine synthesis as a system that has evolved to halt growth at high temperatures, analogous to "thermal fuses" in engineering that shut off electricity to prevent overheating.
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Affiliation(s)
- Severin J Schink
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA; Physics of Complex Biosystems, Physics Department, Technical University of Munich, 85748 Garching, Germany.
| | - Zara Gough
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, 85748 Garching, Germany
| | - Elena Biselli
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, 85748 Garching, Germany
| | - Mariel Garcia Huiman
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, 85748 Garching, Germany
| | - Yu-Fang Chang
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Markus Basan
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | - Ulrich Gerland
- Physics of Complex Biosystems, Physics Department, Technical University of Munich, 85748 Garching, Germany.
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156
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Soto I, Couvillion M, Hansen KG, McShane E, Moran JC, Barrientos A, Churchman LS. Balanced mitochondrial and cytosolic translatomes underlie the biogenesis of human respiratory complexes. Genome Biol 2022; 23:170. [PMID: 35945592 PMCID: PMC9361522 DOI: 10.1186/s13059-022-02732-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 07/18/2022] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Oxidative phosphorylation (OXPHOS) complexes consist of nuclear and mitochondrial DNA-encoded subunits. Their biogenesis requires cross-compartment gene regulation to mitigate the accumulation of disproportionate subunits. To determine how human cells coordinate mitochondrial and nuclear gene expression processes, we tailored ribosome profiling for the unique features of the human mitoribosome. RESULTS We resolve features of mitochondrial translation initiation and identify a small ORF in the 3' UTR of MT-ND5. Analysis of ribosome footprints in five cell types reveals that average mitochondrial synthesis levels correspond precisely to cytosolic levels across OXPHOS complexes, and these average rates reflect the relative abundances of the complexes. Balanced mitochondrial and cytosolic synthesis does not rely on rapid feedback between the two translation systems, and imbalance caused by mitochondrial translation deficiency is associated with the induction of proteotoxicity pathways. CONCLUSIONS Based on our findings, we propose that human OXPHOS complexes are synthesized proportionally to each other, with mitonuclear balance relying on the regulation of OXPHOS subunit translation across cellular compartments, which may represent a proteostasis vulnerability.
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Affiliation(s)
- Iliana Soto
- Blavatnik Institute, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Mary Couvillion
- Blavatnik Institute, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Katja G Hansen
- Blavatnik Institute, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Erik McShane
- Blavatnik Institute, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - J Conor Moran
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - L Stirling Churchman
- Blavatnik Institute, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
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157
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Sawyer EB, Cortes T. Ribosome profiling enhances understanding of mycobacterial translation. Front Microbiol 2022; 13:976550. [PMID: 35992675 PMCID: PMC9386245 DOI: 10.3389/fmicb.2022.976550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/22/2022] [Indexed: 11/21/2022] Open
Abstract
A recent addition to the -omics toolkit, ribosome profiling, enables researchers to gain insight into the process and regulation of translation by mapping fragments of mRNA protected from nuclease digestion by ribosome binding. In this review, we discuss how ribosome profiling applied to mycobacteria has led to discoveries about translational regulation. Using case studies, we show that the traditional view of “canonical” translation mechanisms needs expanding to encompass features of mycobacterial translation that are more widespread than previously recognized. We also discuss the limitations of the method and potential future developments that could yield further insight into the fundamental biology of this important human pathogen.
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Affiliation(s)
- Elizabeth B. Sawyer
- School of Life Sciences, University of Westminster, London, United Kingdom
- *Correspondence: Elizabeth B. Sawyer,
| | - Teresa Cortes
- Pathogen Gene Regulation Unit, Instituto de Biomedicina de Valencia (IBV), CSIC, Valencia, Spain
- Teresa Cortes,
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158
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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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159
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Payne-Dwyer AL, Syeda AH, Shepherd JW, Frame L, Leake MC. RecA and RecB: probing complexes of DNA repair proteins with mitomycin C in live Escherichia coli with single-molecule sensitivity. JOURNAL OF THE ROYAL SOCIETY, INTERFACE 2022; 19:20220437. [PMID: 35946163 PMCID: PMC9363994 DOI: 10.1098/rsif.2022.0437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The RecA protein and RecBCD complex are key bacterial components for the maintenance and repair of DNA. RecBCD is a helicase-nuclease that uses homologous recombination to resolve double-stranded DNA breaks. It also facilitates coating of single-stranded DNA with RecA to form RecA filaments, a vital step in the double-stranded break DNA repair pathway. However, questions remain about the mechanistic roles of RecA and RecBCD in live cells. Here, we use millisecond super-resolved fluorescence microscopy to pinpoint the spatial localization of fluorescent reporters of RecA or RecB at physiological levels of expression in individual live Escherichia coli cells. By introducing the DNA cross-linker mitomycin C, we induce DNA damage and quantify the resulting steady state changes in stoichiometry, cellular protein copy number and molecular mobilities of RecA and RecB. We find that both proteins accumulate in molecular hotspots to effect repair, resulting in RecA stoichiometries equivalent to several hundred molecules that assemble largely in dimeric subunits before DNA damage, but form periodic subunits of approximately 3-4 molecules within mature filaments of several thousand molecules. Unexpectedly, we find that the physiologically predominant forms of RecB are not only rapidly diffusing monomers, but slowly diffusing dimers.
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Affiliation(s)
- Alex L Payne-Dwyer
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Aisha H Syeda
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Jack W Shepherd
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
| | - Lewis Frame
- School of Natural Sciences, University of York, York YO10 5DD, UK
| | - Mark C Leake
- Department of Physics, University of York, York YO10 5DD, UK.,Department of Biology, University of York, York YO10 5DD, UK
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160
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Rabbers I, Bruggeman FJ. Escherichia coli
robustly expresses ATP synthase at growth rate‐maximizing concentrations. FEBS J 2022; 289:4925-4934. [PMID: 35175666 PMCID: PMC9544884 DOI: 10.1111/febs.16401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/16/2021] [Accepted: 02/15/2022] [Indexed: 11/30/2022]
Abstract
Fitness‐enhancing adaptations of protein expression and its regulation are an important aspect of bacterial evolution. A key question is whether evolution has led to optimal protein expression that maximizes immediate growth rate (short‐term fitness) in a robust manner (consistently across diverse conditions). Alternatively, they could display suboptimal short‐term fitness, because they cannot do better or because they instead strive for long‐term fitness maximization by, for instance, preparing for future conditions. To address this question, we focus on the ATP‐producing enzyme F1F0 H+‐ATPase, which is an abundant enzyme and ubiquitously expressed across conditions. Its expression is highly regulated and dependent on growth rate and nutrient conditions. For instance, during growth on sugars, when metabolism is overflowing acetate, glycolysis supplies most ATP, while H+‐ATPase is the main source of ATP synthesis during growth on acetate. We tested the optimality of H+‐ATPase expression in Escherichia coli across different nutrient conditions. In all tested conditions, wild‐type E. coli expresses its H+‐ATPase remarkably close (within a few per cent) to optimal concentrations that maximize immediate growth rate. This work indicates that bacteria can indeed achieve robust optimal protein expression for immediate growth‐rate maximization.
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Affiliation(s)
- Iraes Rabbers
- Systems Biology Lab, AIMMS VU University Amsterdam The Netherlands
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161
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Radoš D, Donati S, Lempp M, Rapp J, Link H. Homeostasis of the biosynthetic E. coli metabolome. iScience 2022; 25:104503. [PMID: 35754712 PMCID: PMC9218372 DOI: 10.1016/j.isci.2022.104503] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/19/2022] [Accepted: 05/26/2022] [Indexed: 11/22/2022] Open
Abstract
Metabolite concentrations vary across conditions and such metabolome changes are relevant for metabolic and gene regulation. Here, we used LC-MS/MS to explore metabolite concentration changes in Escherichia coli. We measured 101 primary metabolites in 19 experimental conditions that include various nutrients and stresses. Many metabolites showed little variation across conditions and only few metabolites correlated with the growth rate. The least varying metabolites were nucleotides (e.g. UTP had 10% variation) and amino acids (e.g. methionine had 13% variation). These results show that E. coli maintains protein and RNA building blocks within narrow concentration ranges, thus indicating that many feedback mechanisms in biosynthetic pathways contribute to end-product homeostasis. 101 E coli metabolites were measured in 19 conditions Biosynthetic end-products vary little between conditions Few metabolites correlate with the growth rate Metabolome data identify active regulatory metabolites
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Affiliation(s)
- Dušica Radoš
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Stefano Donati
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Martin Lempp
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Johanna Rapp
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Hannes Link
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
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162
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Tomasi M, Caproni E, Benedet M, Zanella I, Giorgetta S, Dalsass M, König E, Gagliardi A, Fantappiè L, Berti A, Tamburini S, Croia L, Di Lascio G, Bellini E, Valensin S, Licata G, Sebastiani G, Dotta F, Armanini F, Cumbo F, Asnicar F, Blanco-Míguez A, Ruggiero E, Segata N, Grandi G, Grandi A. Outer Membrane Vesicles From The Gut Microbiome Contribute to Tumor Immunity by Eliciting Cross-Reactive T Cells. Front Oncol 2022; 12:912639. [PMID: 35847919 PMCID: PMC9281500 DOI: 10.3389/fonc.2022.912639] [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: 04/04/2022] [Accepted: 05/20/2022] [Indexed: 12/03/2022] Open
Abstract
A growing body of evidence supports the notion that the gut microbiome plays an important role in cancer immunity. However, the underpinning mechanisms remain to be fully elucidated. One attractive hypothesis envisages that among the T cells elicited by the plethora of microbiome proteins a few exist that incidentally recognize neo-epitopes arising from cancer mutations (“molecular mimicry (MM)” hypothesis). To support MM, the human probiotic Escherichia coli Nissle was engineered with the SIINFEKL epitope (OVA-E.coli Nissle) and orally administered to C57BL/6 mice. The treatment with OVA-E.coli Nissle, but not with wild type E. coli Nissle, induced OVA-specific CD8+ T cells and inhibited the growth of tumors in mice challenged with B16F10 melanoma cells expressing OVA. The microbiome shotgun sequencing and the sequencing of TCRs from T cells recovered from both lamina propria and tumors provide evidence that the main mechanism of tumor inhibition is mediated by the elicitation at the intestinal site of cross-reacting T cells, which subsequently reach the tumor environment. Importantly, the administration of Outer Membrane Vesicles (OMVs) from engineered E. coli Nissle, as well as from E. coli BL21(DE3)ΔompA, carrying cancer-specific T cell epitopes also elicited epitope-specific T cells in the intestine and inhibited tumor growth. Overall, our data strengthen the important role of MM in tumor immunity and assign a novel function of OMVs in host-pathogen interaction. Moreover, our results pave the way to the exploitation of probiotics and OMVs engineered with tumor specific-antigens as personalized mucosal cancer vaccines.
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Affiliation(s)
- Michele Tomasi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Elena Caproni
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Mattia Benedet
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
- Toscana Life Sciences Foundation, Siena, Italy
| | - Ilaria Zanella
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Sebastiano Giorgetta
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Mattia Dalsass
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Enrico König
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
- Toscana Life Sciences Foundation, Siena, Italy
| | | | | | - Alvise Berti
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Silvia Tamburini
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Lorenzo Croia
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Gabriele Di Lascio
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | | | - Giada Licata
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto Di Mario, c/o Toscana Life Sciences Foundation, Siena, Italy
| | - Guido Sebastiani
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto Di Mario, c/o Toscana Life Sciences Foundation, Siena, Italy
| | - Francesco Dotta
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto Di Mario, c/o Toscana Life Sciences Foundation, Siena, Italy
- Tuscany Centre for Precision Medicine (CReMeP), Siena, Italy
| | - Federica Armanini
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Fabio Cumbo
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Francesco Asnicar
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Aitor Blanco-Míguez
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Eliana Ruggiero
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCSS) Ospedale San Raffaele, Milan, Italy
| | - Nicola Segata
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Guido Grandi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
- *Correspondence: Guido Grandi, ; Alberto Grandi,
| | - Alberto Grandi
- Toscana Life Sciences Foundation, Siena, Italy
- BiOMViS Srl, Siena, Italy
- *Correspondence: Guido Grandi, ; Alberto Grandi,
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163
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Buessecker S, Palmer M, Lai D, Dimapilis J, Mayali X, Mosier D, Jiao JY, Colman DR, Keller LM, St John E, Miranda M, Gonzalez C, Gonzalez L, Sam C, Villa C, Zhuo M, Bodman N, Robles F, Boyd ES, Cox AD, St Clair B, Hua ZS, Li WJ, Reysenbach AL, Stott MB, Weber PK, Pett-Ridge J, Dekas AE, Hedlund BP, Dodsworth JA. An essential role for tungsten in the ecology and evolution of a previously uncultivated lineage of anaerobic, thermophilic Archaea. Nat Commun 2022; 13:3773. [PMID: 35773279 PMCID: PMC9246946 DOI: 10.1038/s41467-022-31452-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 06/17/2022] [Indexed: 11/19/2022] Open
Abstract
Trace metals have been an important ingredient for life throughout Earth's history. Here, we describe the genome-guided cultivation of a member of the elusive archaeal lineage Caldarchaeales (syn. Aigarchaeota), Wolframiiraptor gerlachensis, and its growth dependence on tungsten. A metagenome-assembled genome (MAG) of W. gerlachensis encodes putative tungsten membrane transport systems, as well as pathways for anaerobic oxidation of sugars probably mediated by tungsten-dependent ferredoxin oxidoreductases that are expressed during growth. Catalyzed reporter deposition-fluorescence in-situ hybridization (CARD-FISH) and nanoscale secondary ion mass spectrometry (nanoSIMS) show that W. gerlachensis preferentially assimilates xylose. Phylogenetic analyses of 78 high-quality Wolframiiraptoraceae MAGs from terrestrial and marine hydrothermal systems suggest that tungsten-associated enzymes were present in the last common ancestor of extant Wolframiiraptoraceae. Our observations imply a crucial role for tungsten-dependent metabolism in the origin and evolution of this lineage, and hint at a relic metabolic dependence on this trace metal in early anaerobic thermophiles.
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Affiliation(s)
- Steffen Buessecker
- Department of Earth System Science, Stanford University, Stanford, CA, USA.
| | - Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA.
| | - Dengxun Lai
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
| | - Joshua Dimapilis
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Damon Mosier
- Department of Biology, California State University, San Bernardino, CA, USA
- Department of Geoscience, University of Calgary, Calgary, AB, Canada
| | - Jian-Yu Jiao
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, PR China
| | - Daniel R Colman
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Lisa M Keller
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Emily St John
- Department of Biology, Portland State University, Portland, OR, USA
| | - Michelle Miranda
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Cristina Gonzalez
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Lizett Gonzalez
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Christian Sam
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Christopher Villa
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Madeline Zhuo
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Nicholas Bodman
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Fernando Robles
- Department of Biology, California State University, San Bernardino, CA, USA
| | - Eric S Boyd
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Alysia D Cox
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Brian St Clair
- Department of Chemistry and Geochemistry, Montana Technological University, Butte, MT, USA
| | - Zheng-Shuang Hua
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, PR China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, PR China
- College of Fisheries, Henan Normal University, Xinxiang, PR China
| | | | - Matthew B Stott
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
- Life & Environmental Sciences Department, University of Merced, Merced, CA, USA
| | - Anne E Dekas
- Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, USA
| | - Jeremy A Dodsworth
- Department of Biology, California State University, San Bernardino, CA, USA.
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164
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Savinov A, Fernandez A, Fields S. Mapping functional regions of essential bacterial proteins with dominant-negative protein fragments. Proc Natl Acad Sci U S A 2022; 119:e2200124119. [PMID: 35749361 PMCID: PMC9245647 DOI: 10.1073/pnas.2200124119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/08/2022] [Indexed: 12/26/2022] Open
Abstract
Massively parallel measurements of dominant-negative inhibition by protein fragments have been used to map protein interaction sites and discover peptide inhibitors. However, the underlying principles governing fragment-based inhibition have thus far remained unclear. Here, we adapted a high-throughput inhibitory fragment assay for use in Escherichia coli, applying it to a set of 10 essential proteins. This approach yielded single amino acid resolution maps of inhibitory activity, with peaks localized to functionally important interaction sites, including oligomerization interfaces and folding contacts. Leveraging these data, we performed a systematic analysis to uncover principles of fragment-based inhibition. We determined a robust negative correlation between susceptibility to inhibition and cellular protein concentration, demonstrating that inhibitory fragments likely act primarily by titrating native protein interactions. We also characterized a series of trade-offs related to fragment length, showing that shorter peptides allow higher-resolution mapping but suffer from lower inhibitory activity. We employed an unsupervised statistical analysis to show that the inhibitory activities of protein fragments are largely driven not by generic properties such as charge, hydrophobicity, and secondary structure, but by the more specific characteristics of their bespoke macromolecular interactions. Overall, this work demonstrates fundamental characteristics of inhibitory protein fragment function and provides a foundation for understanding and controlling protein interactions in vivo.
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Affiliation(s)
- Andrew Savinov
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Andres Fernandez
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
| | - Stanley Fields
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Department of Medicine, University of Washington, Seattle, WA 98195
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165
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Divergent Effects of Peptidoglycan Carboxypeptidase DacA on Intrinsic β-Lactam and Vancomycin Resistance. Microbiol Spectr 2022; 10:e0173422. [PMID: 35758683 PMCID: PMC9430164 DOI: 10.1128/spectrum.01734-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Vancomycin and β-lactams are clinically important antibiotics that inhibit the formation of peptidoglycan cross-links, but their binding targets are different. The binding target of vancomycin is d-alanine-d-alanine (d-Ala-d-Ala), whereas that of β-lactam is penicillin-binding proteins (PBPs). In this study, we revealed the divergent effects of peptidoglycan (PG) carboxypeptidase DacA on vancomycin and β-lactam resistance in Escherichia coli and Bacillus subtilis. The deletion of DacA induced sensitivity to most β-lactams, whereas it induced strong resistance toward vancomycin. Notably, both phenotypes did not have a strong association with ld-transpeptidases, which are necessary for the formation of PG 3-3 cross-links and covalent bonds between PG and an Lpp outer membrane (OM) lipoprotein. Vancomycin resistance was induced by an increased amount of decoy d-Ala-d-Ala residues within PG, whereas β-lactam sensitivity was associated with physical interactions between DacA and PBPs. The presence of an OM permeability barrier strongly strengthened vancomycin resistance, but it significantly weakened β-lactam sensitivity. Collectively, our results revealed two distinct functions of DacA, which involved inverse modulation of bacterial resistance to clinically important antibiotics, β-lactams and vancomycin, and presented evidence for a link between DacA and PBPs. IMPORTANCE Bacterial PG hydrolases play important roles in various aspects of bacterial physiology, including cytokinesis, PG synthesis, quality control of PG, PG recycling, and stress adaptation. Of all the PG hydrolases, the role of PG carboxypeptidases is poorly understood, especially regarding their impacts on antibiotic resistance. We have revealed two distinct functions of PG carboxypeptidase DacA with respect to antibiotic resistance. The deletion of DacA led to sensitivity to most β-lactams, while it caused strong resistance to vancomycin. Our study provides novel insights into the roles of PG carboxypeptidases in the regulation of antibiotic resistance and a potential clue for the development of a drug to improve the clinical efficacy of β-lactam antibiotics.
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166
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Hsu KL, Yen HCS, Yeang CH. Cooperative stability renders protein complex formation more robust and controllable. Sci Rep 2022; 12:10490. [PMID: 35729235 PMCID: PMC9213465 DOI: 10.1038/s41598-022-14362-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/06/2022] [Indexed: 11/19/2022] Open
Abstract
Protein complexes are the fundamental units of many biological functions. Despite their many advantages, one major adverse impact of protein complexes is accumulations of unassembled subunits that may disrupt other processes or exert cytotoxic effects. Synthesis of excess subunits can be inhibited via negative feedback control or they can be degraded more efficiently than assembled subunits, with this latter being termed cooperative stability. Whereas controlled synthesis of complex subunits has been investigated extensively, how cooperative stability acts in complex formation remains largely unexplored. To fill this knowledge gap, we have built quantitative models of heteromeric complexes with or without cooperative stability and compared their behaviours in the presence of synthesis rate variations. A system displaying cooperative stability is robust against synthesis rate variations as it retains high dimer/monomer ratios across a broad range of parameter configurations. Moreover, cooperative stability can alleviate the constraint of limited supply of a given subunit and makes complex abundance more responsive to unilateral upregulation of another subunit. We also conducted an in silico experiment to comprehensively characterize and compare four types of circuits that incorporate combinations of negative feedback control and cooperative stability in terms of eight systems characteristics pertaining to optimality, robustness and controllability. Intriguingly, though individual circuits prevailed for distinct characteristics, the system with cooperative stability alone achieved the most balanced performance across all characteristics. Our study provides theoretical justification for the contribution of cooperative stability to natural biological systems and represents a guideline for designing synthetic complex formation systems with desirable characteristics.
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Affiliation(s)
- Kuan-Lun Hsu
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan
| | - Hsueh-Chi S Yen
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan
| | - Chen-Hsiang Yeang
- Institute of Statistical Science, Academia Sinica, 128 Academia Road, Section 2, Taipei, Taiwan.
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167
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Popella L, Jung J, Do PT, Hayward RJ, Barquist L, Vogel J. Comprehensive analysis of PNA-based antisense antibiotics targeting various essential genes in uropathogenic Escherichia coli. Nucleic Acids Res 2022; 50:6435-6452. [PMID: 35687096 PMCID: PMC9226493 DOI: 10.1093/nar/gkac362] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/05/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022] Open
Abstract
Antisense peptide nucleic acids (PNAs) that target mRNAs of essential bacterial genes exhibit specific bactericidal effects in several microbial species, but our mechanistic understanding of PNA activity and their target gene spectrum is limited. Here, we present a systematic analysis of PNAs targeting 11 essential genes with varying expression levels in uropathogenic Escherichia coli (UPEC). We demonstrate that UPEC is susceptible to killing by peptide-conjugated PNAs, especially when targeting the widely-used essential gene acpP. Our evaluation yields three additional promising target mRNAs for effective growth inhibition, i.e.dnaB, ftsZ and rpsH. The analysis also shows that transcript abundance does not predict target vulnerability and that PNA-mediated growth inhibition is not universally associated with target mRNA depletion. Global transcriptomic analyses further reveal PNA sequence-dependent but also -independent responses, including the induction of envelope stress response pathways. Importantly, we show that 9mer PNAs are generally as effective in inhibiting bacterial growth as their 10mer counterparts. Overall, our systematic comparison of a range of PNAs targeting mRNAs of different essential genes in UPEC suggests important features for PNA design, reveals a general bacterial response to PNA conjugates and establishes the feasibility of using PNA antibacterials to combat UPEC.
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Affiliation(s)
- Linda Popella
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080, Würzburg, Germany
| | - Jakob Jung
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080, Würzburg, Germany
| | - Phuong Thao Do
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080, Würzburg, Germany
| | - Regan J Hayward
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080, Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080, Würzburg, Germany.,Faculty of Medicine, University of Würzburg, D-97080, Würzburg, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, D-97080, Würzburg, Germany.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080, Würzburg, Germany.,Faculty of Medicine, University of Würzburg, D-97080, Würzburg, Germany
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168
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Han J, Lee C. Antagonistic regulatory effects of a single cis-acting expression quantitative trait locus between transcription and translation of the MRPL43 gene. BMC Genom Data 2022; 23:42. [PMID: 35659240 PMCID: PMC9167510 DOI: 10.1186/s12863-022-01057-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/23/2022] [Indexed: 01/01/2023] Open
Abstract
Background Heterogeneity of expression quantitative trait locus (eQTL) effects have been shown across gene expression processes. Knowledge on how to produce the heterogeneity is quite limited. This study aims to examine fluctuations in differential gene expression by alleles of sequence variants across expression processes. Results Genome-wide eQTL analyses with transcriptome-wide gene expression data revealed 20 cis-acting eQTLs associated simultaneously with mRNA expression, ribosome occupancy, and protein abundance. A 97 kb-long eQTL signal for mitochondrial ribosomal protein L43 (MRPL43) covered the gene, showing a heterogeneous effect size on gene products across expression stages. One allele of the eQTL was associated with increased mRNA expression and ribosome occupancy but decreased protein abundance. We examined the heterogeneity and found that the eQTL can be attributed to the independent functions of three nucleotide variants, with a strong linkage. NC_000010.11:g.100987606G > T, upstream of MRPL43, may regulate the binding affinity of transcription factors. NC_000010.11:g.100986746C > G, 3 bp from an MRPL43 splice donor site, may alter the splice site. NC_000010.11:g.100978794A > G, in the isoform with a long 3′-UTR, may strengthen the binding affinity of the microRNA. Individuals with the TGG haplotype at these three variants had higher levels of mRNA expression and ribosome occupancy than individuals with the GCA haplotype but lower protein levels, producing the flipped effect throughout the expression process. Conclusions These findings suggest that multiple functional variants in a linkage exert their regulatory functions at different points in the gene expression process, producing a complexity of single eQTLs. Supplementary Information The online version contains supplementary material available at 10.1186/s12863-022-01057-7.
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Affiliation(s)
- Jooyeon Han
- Department of Bioinformatics and Life Science, Soongsil University, Seoul, 06978, South Korea
| | - Chaeyoung Lee
- Department of Bioinformatics and Life Science, Soongsil University, Seoul, 06978, South Korea.
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169
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Lin L, Capozzoli R, Ferrand A, Plum M, Vettiger A, Basler M. Subcellular localization of Type VI secretion system assembly in response to cell–cell contact. EMBO J 2022; 41:e108595. [PMID: 35634969 PMCID: PMC9251886 DOI: 10.15252/embj.2021108595] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 04/18/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria require a number of systems, including the type VI secretion system (T6SS), for interbacterial competition and pathogenesis. The T6SS is a large nanomachine that can deliver toxins directly across membranes of proximal target cells. Since major reassembly of T6SS is necessary after each secretion event, accurate timing and localization of T6SS assembly can lower the cost of protein translocation. Although critically important, mechanisms underlying spatiotemporal regulation of T6SS assembly remain poorly understood. Here, we used super‐resolution live‐cell imaging to show that while Acinetobacter and Burkholderia thailandensis can assemble T6SS at any site, a significant subset of T6SS assemblies localizes precisely to the site of contact between neighboring bacteria. We identified a class of diverse, previously uncharacterized, periplasmic proteins required for this dynamic localization of T6SS to cell–cell contact (TslA). This precise localization is also dependent on the outer membrane porin OmpA. Our analysis links transmembrane communication to accurate timing and localization of T6SS assembly as well as uncovers a pathway allowing bacterial cells to respond to cell–cell contact during interbacterial competition.
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Affiliation(s)
- Lin Lin
- Biozentrum University of Basel Basel Switzerland
| | | | - Alexia Ferrand
- Biozentrum Imaging Core Facility University of Basel Basel Switzerland
| | - Miro Plum
- Biozentrum University of Basel Basel Switzerland
| | | | - Marek Basler
- Biozentrum University of Basel Basel Switzerland
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170
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Verheul J, Lodge A, Yau HCL, Liu X, Boelter G, Liu X, Solovyova AS, Typas A, Banzhaf M, Vollmer W, den Blaauwen T. Early midcell localization of Escherichia coli PBP4 supports the function of peptidoglycan amidases. PLoS Genet 2022; 18:e1010222. [PMID: 35604931 PMCID: PMC9166362 DOI: 10.1371/journal.pgen.1010222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 06/03/2022] [Accepted: 04/27/2022] [Indexed: 11/24/2022] Open
Abstract
Insertion of new material into the Escherichia coli peptidoglycan (PG) sacculus between the cytoplasmic membrane and the outer membrane requires a well-organized balance between synthetic and hydrolytic activities to maintain cell shape and avoid lysis. Since most bacteria carry multiple enzymes carrying the same type of PG hydrolytic activity, we know little about the specific function of given enzymes. Here we show that the DD-carboxy/endopeptidase PBP4 localizes in a PBP1A/LpoA and FtsEX dependent fashion at midcell during septal PG synthesis. Midcell localization of PBP4 requires its non-catalytic domain 3 of unknown function, but not the activity of PBP4 or FtsE. Microscale thermophoresis with isolated proteins shows that PBP4 interacts with NlpI and the FtsEX-interacting protein EnvC, an activator of amidases AmiA and AmiB, which are needed to generate denuded glycan strands to recruit the initiator of septal PG synthesis, FtsN. The domain 3 of PBP4 is needed for the interaction with NlpI and EnvC, but not PBP1A or LpoA. In vivo crosslinking experiments confirm the interaction of PBP4 with PBP1A and LpoA. We propose that the interaction of PBP4 with EnvC, whilst not absolutely necessary for mid-cell recruitment of either protein, coordinates the activities of PBP4 and the amidases, which affects the formation of denuded glycan strands that attract FtsN. Consistent with this model, we found that the divisome assembly at midcell was premature in cells lacking PBP4, illustrating how the complexity of interactions affect the timing of cell division initiation. Peptidoglycan biosynthesis is a major target for antibacterials. The covalently closed peptidoglycan mesh, called sacculus, protects the bacterium from lysis due to its turgor. Sacculus growth is facilitated by the balanced activities of synthases and hydrolases, and disturbing this balance leads to cell lysis and bacterial death. Because of the large number and possible redundant functions of peptidoglycan hydrolases, it has been difficult to decipher their individual functions. In this paper we show that the DD-endopeptidase PBP4 localizes at midcell during septal peptidoglycan synthesis in Escherichia coli and is involved in the timing of the assembly and activation of the division machinery. This shows that inhibition of certain hydrolases could weaken the cells and might enhance antibiotic action.
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Affiliation(s)
- Jolanda Verheul
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Adam Lodge
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hamish C. L. Yau
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Xiaolong Liu
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Gabriela Boelter
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Xinwei Liu
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
- European Molecular Biology Laboratory, Structural & Computational Unit, Heidelberg, Germany
| | - Manuel Banzhaf
- Institute of Microbiology & Infection and School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail: (MB); (WV); (TdB)
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail: (MB); (WV); (TdB)
| | - Tanneke den Blaauwen
- Bacterial Cell Biology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail: (MB); (WV); (TdB)
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171
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Rational Engineering of Non-Ubiquinone Containing Corynebacterium glutamicum for Enhanced Coenzyme Q10 Production. Metabolites 2022; 12:metabo12050428. [PMID: 35629932 PMCID: PMC9145305 DOI: 10.3390/metabo12050428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 11/17/2022] Open
Abstract
Coenzyme Q10 (CoQ10) is a lipid-soluble compound with important physiological functions and is sought after in the food and cosmetic industries owing to its antioxidant properties. In our previous proof of concept, we engineered for CoQ10 biosynthesis the industrially relevant Corynebacterium glutamicum, which does not naturally synthesize any CoQ. Here, liquid chromatography–mass spectrometry (LC–MS) analysis identified two metabolic bottlenecks in the CoQ10 production, i.e., low conversion of the intermediate 10-prenylphenol (10P-Ph) to CoQ10 and the accumulation of isoprenologs with prenyl chain lengths of not only 10, but also 8 to 11 isopentenyl units. To overcome these limitations, the strain was engineered for expression of the Ubi complex accessory factors UbiJ and UbiK from Escherichia coli to increase flux towards CoQ10, and by replacement of the native polyprenyl diphosphate synthase IspB with a decaprenyl diphosphate synthase (DdsA) to select for prenyl chains with 10 isopentenyl units. The best strain UBI6-Rs showed a seven-fold increased CoQ10 content and eight-fold increased CoQ10 titer compared to the initial strain UBI4-Pd, while the abundance of CoQ8, CoQ9, and CoQ11 was significantly reduced. This study demonstrates the application of the recent insight into CoQ biosynthesis to improve metabolic engineering of a heterologous CoQ10 production strain.
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172
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Abstract
Temperature impacts biological systems across all length and timescales. Cells and the enzymes that comprise them respond to temperature fluctuations on short timescales, and temperature can affect protein folding, the molecular composition of cells, and volume expansion. Entire ecosystems exhibit temperature-dependent behaviors, and global warming threatens to disrupt thermal homeostasis in microbes that are important for human and planetary health. Intriguingly, the growth rate of most species follows the Arrhenius law of equilibrium thermodynamics, with an activation energy similar to that of individual enzymes but with maximal growth rates and over temperature ranges that are species specific. In this review, we discuss how the temperature dependence of critical cellular processes, such as the central dogma and membrane fluidity, contributes to the temperature dependence of growth. We conclude with a discussion of adaptation to temperature shifts and the effects of temperature on evolution and on the properties of microbial ecosystems.
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Affiliation(s)
- Benjamin D Knapp
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA;
| | - Kerwyn Casey Huang
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA; .,Department of Bioengineering, Stanford University, Stanford, California, USA.,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA.,Chan Zuckerberg Biohub, San Francisco, California, USA
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173
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Hogan AM, Cardona ST. Gradients in gene essentiality reshape antibacterial research. FEMS Microbiol Rev 2022; 46:fuac005. [PMID: 35104846 PMCID: PMC9075587 DOI: 10.1093/femsre/fuac005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/03/2023] Open
Abstract
Essential genes encode the processes that are necessary for life. Until recently, commonly applied binary classifications left no space between essential and non-essential genes. In this review, we frame bacterial gene essentiality in the context of genetic networks. We explore how the quantitative properties of gene essentiality are influenced by the nature of the encoded process, environmental conditions and genetic background, including a strain's distinct evolutionary history. The covered topics have important consequences for antibacterials, which inhibit essential processes. We argue that the quantitative properties of essentiality can thus be used to prioritize antibacterial cellular targets and desired spectrum of activity in specific infection settings. We summarize our points with a case study on the core essential genome of the cystic fibrosis pathobiome and highlight avenues for targeted antibacterial development.
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Affiliation(s)
- Andrew M Hogan
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543 - 745 Bannatyne Avenue, Winnipeg, Manitoba, R3E 0J9, Canada
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174
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Bayer T, Pfaff L, Branson Y, Becker A, Wu S, Bornscheuer UT, Wei R. Biosensor and chemo-enzymatic one-pot cascade applications to detect and transform PET-derived terephthalic acid in living cells. iScience 2022; 25:104326. [PMID: 35602945 PMCID: PMC9117539 DOI: 10.1016/j.isci.2022.104326] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/04/2022] [Accepted: 04/26/2022] [Indexed: 01/14/2023] Open
Abstract
Plastic waste imposes a serious problem to the environment and society. Hence, strategies for a circular plastic economy are demanded. One strategy is the engineering of polyester hydrolases toward higher activity for the biotechnological recycling of polyethylene terephthalate (PET). To provide tools for the rapid characterization of PET hydrolases and the detection of degradation products like terephthalic acid (TPA), we coupled a carboxylic acid reductase (CAR) and the luciferase LuxAB. CAR converted TPA into the corresponding aldehydes in Escherichia coli, which yielded bioluminescence that not only semiquantitatively reflected amounts of TPA in hydrolysis samples but is suitable as a high-throughput screening assay to assess PET hydrolase activity. Furthermore, the CAR-catalyzed synthesis of terephthalaldehyde was combined with a reductive amination cascade in a one-pot setup yielding the corresponding diamine, suggesting a new strategy for the transformation of TPA as a product obtained from PET biodegradation. First bioreduction of terephthalic acid (TPA) by a carboxylic acid reductase in vivo Real-time, high-throughput detection of TPA-derived aldehydes by luciferase LuxAB Bioluminescence reflects TPA amounts, assessing (engineered) PET hydrolase activity Transformation of TPA into the diamine through chemo-enzymatic one-pot cascade
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Affiliation(s)
- Thomas Bayer
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
- Institute of Molecular Biotechnology, TU Graz, Petersgasse 14, 8010 Graz, Austria
- Corresponding author
| | - Lara Pfaff
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
| | - Yannick Branson
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
| | - Aileen Becker
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
| | - Shuke Wu
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
- College of Life Science & Technology, Huazhong Agricultural University, Shizishan Street 1, Wuhan 430070, China
| | - Uwe T. Bornscheuer
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
| | - Ren Wei
- Institute of Biochemistry, Department of Biotechnology & Enzyme Catalysis, University of Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany
- Corresponding author
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175
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The ArcAB Two-Component System: Function in Metabolism, Redox Control, and Infection. Microbiol Mol Biol Rev 2022; 86:e0011021. [PMID: 35442087 PMCID: PMC9199408 DOI: 10.1128/mmbr.00110-21] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
ArcAB, also known as the Arc system, is a member of the two-component system family of bacterial transcriptional regulators and is composed of sensor kinase ArcB and response regulator ArcA. In this review, we describe the structure and function of these proteins and assess the state of the literature regarding ArcAB as a sensor of oxygen consumption. The bacterial quinone pool is the primary modulator of ArcAB activity, but questions remain for how this regulation occurs. This review highlights the role of quinones and their oxidation state in activating and deactivating ArcB and compares competing models of the regulatory mechanism. The cellular processes linked to ArcAB regulation of central metabolic pathways and potential interactions of the Arc system with other regulatory systems are also reviewed. Recent evidence for the function of ArcAB under aerobic conditions is challenging the long-standing characterization of this system as strictly an anaerobic global regulator, and the support for additional ArcAB functionality in this context is explored. Lastly, ArcAB-controlled cellular processes with relevance to infection are assessed.
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176
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Wang N, Zhang T, Du S, Zhou Y, Chen Y. How Do MinC-D Copolymers Act on Z-Ring Localization Regulation? A New Model of Bacillus subtilis Min System. Front Microbiol 2022; 13:841171. [PMID: 35495694 PMCID: PMC9051478 DOI: 10.3389/fmicb.2022.841171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
Division site selection in rod-shaped bacteria is strictly regulated spatially by the Min system. Although many sophisticated studies, including in vitro recombination, have tried to explain these regulations, the precise mechanisms are still unclear. A previous model suggested that the concentration gradient of MinC, an FtsZ inhibitor, regulates the position of the Z-ring in the cell. In Escherichia coli, the oscillation of MinCDE proteins leads to a gradient of Min proteins with the average concentration being lowest in the middle and highest near the poles. In contrast to the Min system of E. coli, the Min system of Bacillus subtilis lacks MinE and exhibits a stable concentration distribution, which is regulated by the binding of DivIVA to the negative curvature membrane. The Min proteins first accumulate at the poles of the cell and relocalize near the division site when the membrane invagination begins. It is inconsistent with the previous model of high concentrations of MinC inhibiting Z-ring formation. Our preliminary data here using electron microscopy and light scattering technology reported that B. subtilis MinC (BsMinC) and MinD (BsMinD) also assembled into large straight copolymers in the presence of ATP, similar to the Min proteins of E. coli. Their assembly is fast and dominated by MinD concentration. When BsMinD is 5 μM, a clear light scattering signal can be observed even at 0.3 μM BsMinC. Here, we propose a new model based on the MinC-D copolymers. In our hypothesis, it is not the concentration gradient of MinC, but the MinC-D copolymer assembled in the region of high concentration MinD that plays a key role in the regulation of Z-ring positioning. In B. subtilis, the regions with high MinD concentration are initially at both ends of the cell and then appear at midcell when cell division began. MinC-D copolymer will polymerize and form a complex with MinJ and DivIVA. These complexes capture FtsZ protofilaments to prevent their diffusion away from the midcell and narrow the Z-ring in the middle of the cell.
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Affiliation(s)
- Na Wang
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, China
| | - Tingting Zhang
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi’an, China
| | - Shuheng Du
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, China
| | - Yao Zhou
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, China
| | - Yaodong Chen
- Key Laboratory of Resources Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi Province, Northwest University, Xi’an, China
- *Correspondence: Yaodong Chen,
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177
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Jeon WJ, Cho H. A Cell Wall Hydrolase MepH Is Negatively Regulated by Proteolysis Involving Prc and NlpI in Escherichia coli. Front Microbiol 2022; 13:878049. [PMID: 35418955 PMCID: PMC8996183 DOI: 10.3389/fmicb.2022.878049] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
Cell wall assembly of Gram-negative bacteria requires DD-endopeptidase activity that cleaves peptidoglycan (PG) crosslinks in addition to PG synthetic activity, and the activity of DD-endopeptidases needs to be tightly regulated to maintain cell wall integrity during PG expansion. Among the major DD-endopeptidases functioning for PG assembly in Escherichia coli, MepS and MepM have been shown to be negatively controlled by the periplasmic protease Prc. In this study, we performed a genetic selection using the synthetic lethality between the mepS and mepM mutations in rich medium to uncover regulatory mechanisms controlling the activity of DD-endopeptidases other than MepS and MepM. This selection revealed mutations in prc and nlpI as suppressors. Gene deletion analyses revealed that MepH is required for suppression of the MepS— MepM— growth defect by the prc or nlpI mutation. We also discovered that MepH is directly degraded by Prc and that this degradation is further promoted by NlpI. Thus, our study showed that all three DD-endopeptidases which play major roles in PG assembly of E. coli under normal physiological conditions are controlled by a common periplasmic protease.
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Affiliation(s)
- Wook-Jong Jeon
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Hongbaek Cho
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon, South Korea
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178
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Crack JC, Balasiny BK, Bennett SP, Rolfe MD, Froes A, MacMillan F, Green J, Cole JA, Le Brun NE. The Di-Iron Protein YtfE Is a Nitric Oxide-Generating Nitrite Reductase Involved in the Management of Nitrosative Stress. J Am Chem Soc 2022; 144:7129-7145. [PMID: 35416044 PMCID: PMC9052748 DOI: 10.1021/jacs.1c12407] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
![]()
Previously characterized
nitrite reductases fall into three classes:
siroheme-containing enzymes (NirBD), cytochrome c hemoproteins (NrfA and NirS), and copper-containing enzymes (NirK).
We show here that the di-iron protein YtfE represents a physiologically
relevant new class of nitrite reductases. Several functions have been
previously proposed for YtfE, including donating iron for the repair
of iron–sulfur clusters that have been damaged by nitrosative
stress, releasing nitric oxide (NO) from nitrosylated iron, and reducing
NO to nitrous oxide (N2O). Here, in vivo reporter assays confirmed that Escherichia coli YtfE increased cytoplasmic NO production from nitrite. Spectroscopic
and mass spectrometric investigations revealed that the di-iron site
of YtfE exists in a mixture of forms, including nitrosylated and nitrite-bound,
when isolated from nitrite-supplemented, but not nitrate-supplemented,
cultures. Addition of nitrite to di-ferrous YtfE resulted in nitrosylated
YtfE and the release of NO. Kinetics of nitrite reduction were dependent
on the nature of the reductant; the lowest Km, measured for the di-ferrous form, was ∼90 μM,
well within the intracellular nitrite concentration range. The vicinal
di-cysteine motif, located in the N-terminal domain of YtfE, was shown
to function in the delivery of electrons to the di-iron center. Notably,
YtfE exhibited very low NO reductase activity and was only able to
act as an iron donor for reconstitution of apo-ferredoxin under conditions
that damaged its di-iron center. Thus, YtfE is a high-affinity, low-capacity
nitrite reductase that we propose functions to relieve nitrosative
stress by acting in combination with the co-regulated NO-consuming
enzymes Hmp and Hcp.
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Affiliation(s)
- Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Basema K Balasiny
- Institute of Microbiology and Infection and School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Sophie P Bennett
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Matthew D Rolfe
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Afonso Froes
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Fraser MacMillan
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Jeffrey Green
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Jeffrey A Cole
- Institute of Microbiology and Infection and School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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179
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Ponath F, Hör J, Vogel J. An overview of gene regulation in bacteria by small RNAs derived from mRNA 3' ends. FEMS Microbiol Rev 2022; 46:6564598. [PMID: 35388892 PMCID: PMC9438474 DOI: 10.1093/femsre/fuac017] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Over the past two decades, small noncoding RNAs (sRNAs) that regulate mRNAs by short base pairing have gone from a curiosity to a major class of post-transcriptional regulators in bacteria. They are integral to many stress responses and regulatory circuits, affecting almost all aspects of bacterial life. Following pioneering sRNA searches in the early 2000s, the field quickly focused on conserved sRNA genes in the intergenic regions of bacterial chromosomes. Yet, it soon emerged that there might be another rich source of bacterial sRNAs—processed 3′ end fragments of mRNAs. Several such 3′ end-derived sRNAs have now been characterized, often revealing unexpected, conserved functions in diverse cellular processes. Here, we review our current knowledge of these 3′ end-derived sRNAs—their biogenesis through ribonucleases, their molecular mechanisms, their interactions with RNA-binding proteins such as Hfq or ProQ and their functional scope, which ranges from acting as specialized regulators of single metabolic genes to constituting entire noncoding arms in global stress responses. Recent global RNA interactome studies suggest that the importance of functional 3′ end-derived sRNAs has been vastly underestimated and that this type of cross-regulation between genes at the mRNA level is more pervasive in bacteria than currently appreciated.
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Affiliation(s)
- Falk Ponath
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080 Würzburg, Germany
| | - Jens Hör
- Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), D-97080 Würzburg, Germany.,Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
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180
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Division of labor and collective functionality in Escherichia coli under acid stress. Commun Biol 2022; 5:327. [PMID: 35393532 PMCID: PMC8989999 DOI: 10.1038/s42003-022-03281-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/03/2022] [Indexed: 11/09/2022] Open
Abstract
The acid stress response is an important factor influencing the transmission of intestinal microbes such as the enterobacterium Escherichia coli. E. coli activates three inducible acid resistance systems - the glutamate decarboxylase, arginine decarboxylase, and lysine decarboxylase systems to counteract acid stress. Each system relies on the activity of a proton-consuming reaction catalyzed by a specific amino acid decarboxylase and a corresponding antiporter. Activation of these three systems is tightly regulated by a sophisticated interplay of membrane-integrated and soluble regulators. Using a fluorescent triple reporter strain, we quantitatively illuminated the cellular individuality during activation of each of the three acid resistance (AR) systems under consecutively increasing acid stress. Our studies highlight the advantages of E. coli in possessing three AR systems that enable division of labor in the population, which ensures survival over a wide range of low pH values.
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181
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Terai G, Asai K. QRNAstruct: a method for extracting secondary structural features of RNA via regression with biological activity. Nucleic Acids Res 2022; 50:e73. [PMID: 35390152 PMCID: PMC9303433 DOI: 10.1093/nar/gkac220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 02/15/2022] [Accepted: 03/24/2022] [Indexed: 12/04/2022] Open
Abstract
Recent technological advances have enabled the generation of large amounts of data consisting of RNA sequences and their functional activity. Here, we propose a method for extracting secondary structure features that affect the functional activity of RNA from sequence–activity data. Given pairs of RNA sequences and their corresponding bioactivity values, our method calculates position-specific structural features of the input RNA sequences, considering every possible secondary structure of each RNA. A Ridge regression model is trained using the structural features as feature vectors and the bioactivity values as response variables. Optimized model parameters indicate how secondary structure features affect bioactivity. We used our method to extract intramolecular structural features of bacterial translation initiation sites and self-cleaving ribozymes, and the intermolecular features between rRNAs and Shine–Dalgarno sequences and between U1 RNAs and splicing sites. We not only identified known structural features but also revealed more detailed insights into structure–activity relationships than previously reported. Importantly, the datasets we analyzed here were obtained from different experimental systems and differed in size, sequence length and similarity, and number of RNA molecules involved, demonstrating that our method is applicable to various types of data consisting of RNA sequences and bioactivity values.
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Affiliation(s)
- Goro Terai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan
| | - Kiyoshi Asai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan
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182
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Metelev M, Lundin E, Volkov IL, Gynnå AH, Elf J, Johansson M. Direct measurements of mRNA translation kinetics in living cells. Nat Commun 2022; 13:1852. [PMID: 35388013 PMCID: PMC8986856 DOI: 10.1038/s41467-022-29515-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 03/17/2022] [Indexed: 01/09/2023] Open
Abstract
Ribosome mediated mRNA translation is central to life. The cycle of translation, however, has been characterized mostly using reconstituted systems, with only few techniques applicable for studies in the living cell. Here we describe a live-cell ribosome-labeling method, which allows us to characterize the whole processes of finding and translating an mRNA, using single-molecule tracking techniques. We find that more than 90% of both bacterial ribosomal subunits are engaged in translation at any particular time, and that the 30S and 50S ribosomal subunits spend the same average time bound to an mRNA, revealing that 30S re-initiation on poly-cistronic mRNAs is not prevalent in E. coli. Instead, our results are best explained by substantial 70S re-initiation of translation of poly-cistronic mRNAs, which is further corroborated by experiments with translation initiation inhibitors. Finally, we find that a variety of previously described orthogonal ribosomes, with altered anti-Shine-Dalgarno sequences, show significant binding to endogenous mRNAs.
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Affiliation(s)
- Mikhail Metelev
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Erik Lundin
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Ivan L Volkov
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Arvid H Gynnå
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Johan Elf
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Magnus Johansson
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
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183
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Hayashi-Nishino M, Aoki K, Kishimoto A, Takeuchi Y, Fukushima A, Uchida K, Echigo T, Yagi Y, Hirose M, Iwasaki K, Shin'ya E, Washio T, Furusawa C, Nishino K. Identification of Bacterial Drug-Resistant Cells by the Convolutional Neural Network in Transmission Electron Microscope Images. Front Microbiol 2022; 13:839718. [PMID: 35369486 PMCID: PMC8965347 DOI: 10.3389/fmicb.2022.839718] [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: 12/20/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
The emergence of bacteria that are resistant to antibiotics is common in areas where antibiotics are used widely. The current standard procedure for detecting bacterial drug resistance is based on bacterial growth under antibiotic treatments. Here we describe the morphological changes in enoxacin-resistant Escherichia coli cells and the computational method used to identify these resistant cells in transmission electron microscopy (TEM) images without using antibiotics. Our approach was to create patches from TEM images of enoxacin-sensitive and enoxacin-resistant E. coli strains, use a convolutional neural network for patch classification, and identify the strains on the basis of the classification results. The proposed method was highly accurate in classifying cells, achieving an accuracy rate of 0.94. Using a gradient-weighted class activation mapping to visualize the region of interest, enoxacin-resistant and enoxacin-sensitive cells were characterized by comparing differences in the envelope. Moreover, Pearson's correlation coefficients suggested that four genes, including lpp, the gene encoding the major outer membrane lipoprotein, were strongly associated with the image features of enoxacin-resistant cells.
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Affiliation(s)
- Mitsuko Hayashi-Nishino
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan.,Artificial Intelligence Research Center (AIRC-ISIR), Osaka University, Ibaraki, Japan
| | - Kota Aoki
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Akihiro Kishimoto
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Yuna Takeuchi
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan
| | - Aiko Fukushima
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Kazushi Uchida
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan
| | - Tomio Echigo
- Department of Engineering Informatics, Osaka Electro-Communication University, Neyagawa, Japan
| | - Yasushi Yagi
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Mika Hirose
- Institute for Protein Research, Osaka University, Suita, Japan
| | - Kenji Iwasaki
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Japan
| | - Eitaro Shin'ya
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Takashi Washio
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan
| | - Chikara Furusawa
- RIKEN, Center for Biosystems Dynamics Research, Suita, Japan.,Universal Biology Institute, The University of Tokyo, Tokyo, Japan
| | - Kunihiko Nishino
- SANKEN (Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Japan.,Center for Infectious Disease Education and Research, Osaka University, Suita, Japan
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184
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Sun J, Rutherford ST, Silhavy TJ, Huang KC. Physical properties of the bacterial outer membrane. Nat Rev Microbiol 2022; 20:236-248. [PMID: 34732874 PMCID: PMC8934262 DOI: 10.1038/s41579-021-00638-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2021] [Indexed: 11/09/2022]
Abstract
It has long been appreciated that the Gram-negative outer membrane acts as a permeability barrier, but recent studies have uncovered a more expansive and versatile role for the outer membrane in cellular physiology and viability. Owing to recent developments in microfluidics and microscopy, the structural, rheological and mechanical properties of the outer membrane are becoming apparent across multiple scales. In this Review, we discuss experimental and computational studies that have revealed key molecular factors and interactions that give rise to the spatial organization, limited diffusivity and stress-bearing capacity of the outer membrane. These physical properties suggest broad connections between cellular structure and physiology, and we explore future prospects for further elucidation of the implications of outer membrane construction for cellular fitness and survival.
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Affiliation(s)
- Jiawei Sun
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Steven T. Rutherford
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA 94080, USA,To whom correspondence should be addressed: , ,
| | - Thomas J. Silhavy
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA,To whom correspondence should be addressed: , ,
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA, USA. .,Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA. .,Chan Zuckerberg Biohub, San Francisco, CA, USA.
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185
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Attaibi M, den Blaauwen T. An Updated Model of the Divisome: Regulation of the Septal Peptidoglycan Synthesis Machinery by the Divisome. Int J Mol Sci 2022; 23:3537. [PMID: 35408901 PMCID: PMC8998562 DOI: 10.3390/ijms23073537] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/06/2023] Open
Abstract
The synthesis of a peptidoglycan septum is a fundamental part of bacterial fission and is driven by a multiprotein dynamic complex called the divisome. FtsW and FtsI are essential proteins that synthesize the peptidoglycan septum and are controlled by the regulatory FtsBLQ subcomplex and the activator FtsN. However, their mode of regulation has not yet been uncovered in detail. Understanding this process in detail may enable the development of new compounds to combat the rise in antibiotic resistance. In this review, recent data on the regulation of septal peptidoglycan synthesis is summarized and discussed. Based on structural models and the collected data, multiple putative interactions within FtsWI and with regulators are uncovered. This elaborates on and supports an earlier proposed model that describes active and inactive conformations of the septal peptidoglycan synthesis complex that are stabilized by these interactions. Furthermore, a new model on the spatial organization of the newly synthesized peptidoglycan and the synthesis complex is presented. Overall, the updated model proposes a balance between several allosteric interactions that determine the state of septal peptidoglycan synthesis.
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Affiliation(s)
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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186
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Pi H, Weiss A, Laut CL, Grunenwald CM, Lin HK, Yi XI, Stauff DL, Skaar EP. An RNA-binding protein acts as a major post-transcriptional modulator in Bacillus anthracis. Nat Commun 2022; 13:1491. [PMID: 35314695 PMCID: PMC8938561 DOI: 10.1038/s41467-022-29209-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 03/01/2022] [Indexed: 12/28/2022] Open
Abstract
HitRS is a two-component system that responds to cell envelope damage in the human pathogen Bacillus anthracis. Here we identify an RNA-binding protein, KrrA, that regulates HitRS function by modulating the stability of the hitRS mRNA. In addition to hitRS, KrrA binds to over 70 RNAs and, directly or indirectly, affects the expression of over 150 genes involved in multiple processes, including genetic competence, sporulation, RNA turnover, DNA repair, transport, and cellular metabolism. KrrA does not exhibit detectable nuclease activity in vitro, and thus the mechanism by which it modulates mRNA stability remains unclear.
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Affiliation(s)
- Hualiang Pi
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN, USA
| | - Andy Weiss
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN, USA
| | - Clare L Laut
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN, USA
| | - Caroline M Grunenwald
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN, USA
| | - Hannah K Lin
- Department of Biology, Grove City College, Grove City, PA, USA
| | - Xinjie I Yi
- Department of Biology, Grove City College, Grove City, PA, USA
| | - Devin L Stauff
- Department of Biology, Grove City College, Grove City, PA, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN, USA.
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187
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Pla-Prats C, Thomä NH. Quality control of protein complex assembly by the ubiquitin-proteasome system. Trends Cell Biol 2022; 32:696-706. [PMID: 35300891 DOI: 10.1016/j.tcb.2022.02.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 12/12/2022]
Abstract
The majority of human proteins operate as multimeric complexes with defined compositions and distinct architectures. How the assembly of these complexes is surveyed and how defective complexes are recognized is just beginning to emerge. In eukaryotes, over 600 E3 ubiquitin ligases form part of the ubiquitin-proteasome system (UPS) which detects structural characteristics in its target proteins and selectively induces their degradation. The UPS has recently been shown to oversee key quality control steps during the assembly of protein complexes. We review recent findings on how E3 ubiquitin ligases regulate protein complex assembly and highlight unanswered questions relating to their mechanism of action.
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Affiliation(s)
- Carlos Pla-Prats
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland; Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
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188
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Kumar S, Mollo A, Kahne D, Ruiz N. The Bacterial Cell Wall: From Lipid II Flipping to Polymerization. Chem Rev 2022; 122:8884-8910. [PMID: 35274942 PMCID: PMC9098691 DOI: 10.1021/acs.chemrev.1c00773] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The peptidoglycan (PG) cell wall is an extra-cytoplasmic glycopeptide polymeric structure that protects bacteria from osmotic lysis and determines cellular shape. Since the cell wall surrounds the cytoplasmic membrane, bacteria must add new material to the PG matrix during cell elongation and division. The lipid-linked precursor for PG biogenesis, Lipid II, is synthesized in the inner leaflet of the cytoplasmic membrane and is subsequently translocated across the bilayer so that the PG building block can be polymerized and cross-linked by complex multiprotein machines. This review focuses on major discoveries that have significantly changed our understanding of PG biogenesis in the past decade. In particular, we highlight progress made toward understanding the translocation of Lipid II across the cytoplasmic membrane by the MurJ flippase, as well as the recent discovery of a novel class of PG polymerases, the SEDS (shape, elongation, division, and sporulation) glycosyltransferases RodA and FtsW. Since PG biogenesis is an effective target of antibiotics, these recent developments may lead to the discovery of much-needed new classes of antibiotics to fight bacterial resistance.
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Affiliation(s)
- Sujeet Kumar
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
| | - Aurelio Mollo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Natividad Ruiz
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, United States
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189
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Ramos C, Hernández-Tamayo R, López-Sanz M, Carrasco B, Serrano E, Alonso JC, Graumann PL, Ayora S. The RecD2 helicase balances RecA activities. Nucleic Acids Res 2022; 50:3432-3444. [PMID: 35234892 PMCID: PMC8989531 DOI: 10.1093/nar/gkac131] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 11/30/2022] Open
Abstract
DNA helicases of the RecD2 family are ubiquitous. Bacillus subtilis RecD2 in association with the single-stranded binding protein SsbA may contribute to replication fork progression, but its detailed action remains unknown. In this work, we explore the role of RecD2 during DNA replication and its interaction with the RecA recombinase. RecD2 inhibits replication restart, but this effect is not observed in the absence of SsbA. RecD2 slightly affects replication elongation. RecA inhibits leading and lagging strand synthesis, and RecD2, which physically interacts with RecA, counteracts this negative effect. In vivo results show that recD2 inactivation promotes RecA–ssDNA accumulation at low mitomycin C levels, and that RecA threads persist for a longer time after induction of DNA damage. In vitro, RecD2 modulates RecA-mediated DNA strand-exchange and catalyzes branch migration. These findings contribute to our understanding of how RecD2 may contribute to overcome a replicative stress, removing RecA from the ssDNA and, thus, it may act as a negative modulator of RecA filament growth.
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Affiliation(s)
- Cristina Ramos
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
| | - Rogelio Hernández-Tamayo
- SYNMIKRO, LOEWE-Zentrum für Synthetische Mikrobiologie, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - María López-Sanz
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
| | - Begoña Carrasco
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
| | - Ester Serrano
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
| | - Juan C Alonso
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
| | - Peter L Graumann
- SYNMIKRO, LOEWE-Zentrum für Synthetische Mikrobiologie, Hans-Meerwein-Straße 6, 35043 Marburg, Germany.,Fachbereich Chemie, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Silvia Ayora
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, 28049Madrid, Spain
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190
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Lewandowska D, Orr J, Schreiber M, Colas I, Ramsay L, Zhang R, Waugh R. The proteome of developing barley anthers during meiotic prophase I. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1464-1482. [PMID: 34758083 PMCID: PMC8890616 DOI: 10.1093/jxb/erab494] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/08/2021] [Indexed: 05/11/2023]
Abstract
Flowering plants reproduce sexually by combining a haploid male and female gametophyte during fertilization. Male gametophytes are localized in the anthers, each containing reproductive (meiocyte) and non-reproductive tissue necessary for anther development and maturation. Meiosis, where chromosomes pair and exchange their genetic material during a process called recombination, is one of the most important and sensitive stages in breeding, ensuring genetic diversity. Most anther development studies have focused on transcript variation, but very few have been correlated with protein abundance. Taking advantage of a recently published barley anther transcriptomic (BAnTr) dataset and a newly developed sensitive mass spectrometry-based approach to analyse the barley anther proteome, we conducted high-resolution mass spectrometry analysis of barley anthers, collected at six time points and representing their development from pre-meiosis to metaphase. Each time point was carefully staged using immunocytology, providing a robust and accurate staging mirroring our previous BAnTr dataset. We identified >6100 non-redundant proteins including 82 known and putative meiotic proteins. Although the protein abundance was relatively stable throughout prophase I, we were able to quantify the dynamic variation of 336 proteins. We present the first quantitative comparative proteomics study of barley anther development during meiotic prophase I when the important process of homologous recombination is taking place.
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Affiliation(s)
- Dominika Lewandowska
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Jamie Orr
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Miriam Schreiber
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Isabelle Colas
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Luke Ramsay
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Runxuan Zhang
- Information and Computational Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Robbie Waugh
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
- Division of Plant Sciences, University of Dundee, The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Waite Research Precinct, Glen Osmond, SA 5064, Australia
- Correspondence:
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191
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Abstract
Persisters represent a small subpopulation of cells that are tolerant of killing by antibiotics and are implicated in the recalcitrance of chronic infections to antibiotic therapy. One general theme has emerged regarding persisters formed by different bacterial species, namely, a state of relative dormancy characterized by diminished activity of antibiotic targets. Within this framework, a number of studies have linked persister formation to stochastic decreases in energy-generating components, leading to low ATP and target activity. In this study, we screen knockouts in the main global regulators of Escherichia coli for their effect on persisters. A knockout in integration host factor (IHF) had elevated ATP and a diminished level of persisters. This was accompanied by an overexpression of isocitrate dehydrogenase (Icd) and a downregulation of isocitrate lyase (AceA), two genes located at the bifurcation between the tricarboxylic acid (TCA) cycle and the glyoxylate bypass. Using a translational ihfA-mVenus fusion, we sort out rare bright cells, and this subpopulation is enriched in persisters. Our results suggest that noise in the expression of ihf produces rare cells with low Icd/high AceA, diverting substrates into the glyoxylate bypass, which decreases ATP, leading to antibiotic-tolerant persisters. We further examine noise in a simple model, the lac operon, and show that a knockout of the lacI repressor increases expression of the operon and decreases persister formation. Our results suggest that noise quenching by overexpression serves as a general approach to determine the nature of persister genes in a variety of bacterial species and conditions. IMPORTANCE Persisters are phenotypic variants that survive exposure to antibiotics through temporary dormancy. Mutants with increased levels of persisters have been identified in clinical isolates, and evidence suggests these cells contribute to chronic infections and antibiotic treatment failure. Understanding the underlying mechanism of persister formation and tolerance is important for developing therapeutic approaches to treat chronic infections. In this study, we examine a global regulator, IHF, that plays a role in persister formation. We find that noise in expression of IHF contributes to persister formation, likely by regulating the switch between the TCA cycle that efficiently produces energy and the glyoxylate bypass. We extend this study to a simple model lac operon and show that when grown on lactose as the sole carbon source, noise in its expression influences ATP levels and determines persister formation. This noise is quenched by overexpression of the lac operon, providing a simple approach to test the involvement of a gene in persister formation.
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192
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Pozdeev G, Beckett MC, Mogre A, Thomson NR, Dorman CJ. Reciprocally rewiring and repositioning the Integration Host Factor (IHF) subunit genes in Salmonella enterica serovar Typhimurium: impacts on physiology and virulence. Microb Genom 2022; 8. [PMID: 35166652 PMCID: PMC8942017 DOI: 10.1099/mgen.0.000768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The Integration Host Factor (IHF) is a heterodimeric nucleoid-associated protein that plays roles in bacterial nucleoid architecture and genome-wide gene regulation. The ihfA and ihfB genes encode the subunits and are located 350 kbp apart, in the Right replichore of the Salmonella chromosome. IHF is composed of one IhfA and one IhfB subunit. Despite this 1 : 1 stoichiometry, MS revealed that IhfB is produced in 2-fold excess over IhfA. We re-engineered Salmonella to exchange reciprocally the protein-coding regions of ihfA and ihfB, such that each relocated protein-encoding region was driven by the expression signals of the other's gene. MS showed that in this 'rewired' strain, IhfA is produced in excess over IhfB, correlating with enhanced stability of the hybrid ihfB-ihfA mRNA that was expressed from the ihfB promoter. Nevertheless, the rewired strain grew at a similar rate to the wild-type and was similar in competitive fitness. However, compared to the wild-type, it was less motile, had growth-phase-specific reductions in SPI-1 and SPI-2 gene expression, and was engulfed at a higher rate by RAW macrophage. Our data show that while exchanging the physical locations of its ihf genes and the rewiring of their regulatory circuitry are well tolerated in Salmonella, genes involved in the production of type 3 secretion systems exhibit dysregulation accompanied by altered phenotypes.
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Affiliation(s)
- German Pozdeev
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Michael C Beckett
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Aalap Mogre
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
| | | | - Charles J Dorman
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
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193
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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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194
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BACCELLI P, RACHEDI R, SERRANO B, PETITI M, BERNARD C, HOUOT L, DUCHE D. Timing of TolA and TolQ recruitment at the septum depends on the functionality of the Tol-Pal system. J Mol Biol 2022; 434:167519. [DOI: 10.1016/j.jmb.2022.167519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/11/2022] [Accepted: 02/24/2022] [Indexed: 10/19/2022]
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195
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Mandela E, Stubenrauch CJ, Ryoo D, Hwang H, Cohen EJ, Torres VVL, Deo P, Webb CT, Huang C, Schittenhelm RB, Beeby M, Gumbart JC, Lithgow T, Hay ID. Adaptation of the periplasm to maintain spatial constraints essential for cell envelope processes and cell viability. eLife 2022; 11:73516. [PMID: 35084330 PMCID: PMC8824477 DOI: 10.7554/elife.73516] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/21/2022] [Indexed: 11/17/2022] Open
Abstract
The cell envelope of Gram-negative bacteria consists of two membranes surrounding a periplasm and peptidoglycan layer. Molecular machines spanning the cell envelope depend on spatial constraints and load-bearing forces across the cell envelope and surface. The mechanisms dictating spatial constraints across the cell envelope remain incompletely defined. In Escherichia coli, the coiled-coil lipoprotein Lpp contributes the only covalent linkage between the outer membrane and the underlying peptidoglycan layer. Using proteomics, molecular dynamics, and a synthetic lethal screen, we show that lengthening Lpp to the upper limit does not change the spatial constraint but is accommodated by other factors which thereby become essential for viability. Our findings demonstrate E. coli expressing elongated Lpp does not simply enlarge the periplasm in response, but the bacteria accommodate by a combination of tilting Lpp and reducing the amount of the covalent bridge. By genetic screening, we identified all of the genes in E. coli that become essential in order to enact this adaptation, and by quantitative proteomics discovered that very few proteins need to be up- or down-regulated in steady-state levels in order to accommodate the longer Lpp. We observed increased levels of factors determining cell stiffness, a decrease in membrane integrity, an increased membrane vesiculation and a dependance on otherwise non-essential tethers to maintain lipid transport and peptidoglycan biosynthesis. Further this has implications for understanding how spatial constraint across the envelope controls processes such as flagellum-driven motility, cellular signaling, and protein translocation
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Affiliation(s)
- Eric Mandela
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | | | - David Ryoo
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, United States
| | - Hyea Hwang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Eli J Cohen
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Pankaj Deo
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Chaille T Webb
- Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Cheng Huang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Ralf B Schittenhelm
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia
| | - Morgan Beeby
- Department of Life Sciencesa, Imperial College London, London, United Kingdom
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, United States
| | - Trevor Lithgow
- Department of Microbiology, Monash University, Melbourne, Australia
| | - Iain D Hay
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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196
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The context of the ribosome binding site in mRNAs defines specificity of action of kasugamycin, an inhibitor of translation initiation. Proc Natl Acad Sci U S A 2022; 119:2118553119. [PMID: 35064089 PMCID: PMC8794815 DOI: 10.1073/pnas.2118553119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2021] [Indexed: 11/18/2022] Open
Abstract
Several antibiotics targeting the large ribosomal subunit interfere with translation in a context-specific manner, preventing ribosomes from polymerizing specific amino acid sequences. Here, we reveal kasugamycin as a small ribosomal subunit-targeting antibiotic whose action depends on the sequence context of the untranslated messenger RNA (mRNA) segments. We show that kasugamycin-induced ribosomal arrest at the start codons of the genes and the resulting inhibition of gene expression depend on the nature of the mRNA nucleotide immediately preceding the start codon and on the proximity of the stop codon of the upstream cistron. Our findings underlie the importance of mRNA context for the action of protein synthesis inhibitors and might help to guide the development of better antibiotics. Kasugamycin (KSG) is an aminoglycoside antibiotic widely used in agriculture and exhibits considerable medical potential. Previous studies suggested that KSG interferes with translation by blocking binding of canonical messenger RNA (mRNA) and initiator transfer tRNA (tRNA) to the small ribosomal subunit, thereby preventing initiation of protein synthesis. Here, by using genome-wide approaches, we show that KSG can interfere with translation even after the formation of the 70S initiation complex on mRNA, as the extent of KSG-mediated translation inhibition correlates with increased occupancy of start codons by 70S ribosomes. Even at saturating concentrations, KSG does not completely abolish translation, allowing for continuing expression of some Escherichia coli proteins. Differential action of KSG significantly depends on the nature of the mRNA residue immediately preceding the start codon, with guanine in this position being the most conducive to inhibition by the drug. In addition, the activity of KSG is attenuated by translational coupling as genes whose start codons overlap with the coding regions or the stop codons of the upstream cistrons tend to be less susceptible to drug-mediated inhibition. Altogether, our findings reveal KSG as an example of a small ribosomal subunit-targeting antibiotic with a well-pronounced context specificity of action.
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197
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Vazquez-Laslop N, Sharma CM, Mankin A, Buskirk AR. Identifying Small Open Reading Frames in Prokaryotes with Ribosome Profiling. J Bacteriol 2022; 204:e0029421. [PMID: 34339296 PMCID: PMC8765392 DOI: 10.1128/jb.00294-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small proteins encoded by open reading frames (ORFs) shorter than 50 codons (small ORFs [sORFs]) are often overlooked by annotation engines and are difficult to characterize using traditional biochemical techniques. Ribosome profiling has tremendous potential to empirically improve the annotations of prokaryotic genomes. Recent improvements in ribosome profiling methods for bacterial model organisms have revealed many new sORFs in well-characterized genomes. Antibiotics that trap ribosomes just after initiation have played a key role in these developments by allowing the unambiguous identification of the start codons (and, hence, the reading frame) for novel ORFs. Here, we describe these new methods and highlight critical controls and considerations for adapting ribosome profiling to different prokaryotic species.
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Affiliation(s)
- Nora Vazquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Cynthia M. Sharma
- Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Alexander Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Allen R. Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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198
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Yadavalli SS, Yuan J. Bacterial Small Membrane Proteins: the Swiss Army Knife of Regulators at the Lipid Bilayer. J Bacteriol 2022; 204:e0034421. [PMID: 34516282 PMCID: PMC8765417 DOI: 10.1128/jb.00344-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Small membrane proteins represent a subset of recently discovered small proteins (≤100 amino acids), which are a ubiquitous class of emerging regulators underlying bacterial adaptation to environmental stressors. Until relatively recently, small open reading frames encoding these proteins were not designated genes in genome annotations. Therefore, our understanding of small protein biology was primarily limited to a few candidates associated with previously characterized larger partner proteins. Following the first systematic analyses of small proteins in Escherichia coli over a decade ago, numerous small proteins across different bacteria have been uncovered. An estimated one-third of these newly discovered proteins in E. coli are localized to the cell membrane, where they may interact with distinct groups of membrane proteins, such as signal receptors, transporters, and enzymes, and affect their activities. Recently, there has been considerable progress in functionally characterizing small membrane protein regulators aided by innovative tools adapted specifically to study small proteins. Our review covers prototypical proteins that modulate a broad range of cellular processes, such as transport, signal transduction, stress response, respiration, cell division, sporulation, and membrane stability. Thus, small membrane proteins represent a versatile group of physiology regulators at the membrane and the whole cell. Additionally, small membrane proteins have the potential for clinical applications, where some of the proteins may act as antibacterial agents themselves while others serve as alternative drug targets for the development of novel antimicrobials.
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Affiliation(s)
- Srujana S. Yadavalli
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey, USA
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
| | - Jing Yuan
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
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199
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Matera G, Altuvia Y, Gerovac M, El Mouali Y, Margalit H, Vogel J. Global RNA interactome of Salmonella discovers a 5' UTR sponge for the MicF small RNA that connects membrane permeability to transport capacity. Mol Cell 2022; 82:629-644.e4. [PMID: 35063132 DOI: 10.1016/j.molcel.2021.12.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 10/04/2021] [Accepted: 12/21/2021] [Indexed: 12/13/2022]
Abstract
The envelope of Gram-negative bacteria is a vital barrier that must balance protection and nutrient uptake. Small RNAs are crucial regulators of the envelope composition and function. Here, using RIL-seq to capture the Hfq-mediated RNA-RNA interactome in Salmonella enterica, we discover envelope-related riboregulators, including OppX. We show that OppX acts as an RNA sponge of MicF sRNA, a prototypical porin repressor. OppX originates from the 5' UTR of oppABCDF, encoding the major inner-membrane oligopeptide transporter, and sequesters MicF's seed region to derepress the synthesis of the porin OmpF. Intriguingly, OppX operates as a true sponge, storing MicF in an inactive complex without affecting its levels or stability. Conservation of the opp-OppX-MicF-ompF axis in related bacteria suggests that it serves an important mechanism, adjusting envelope porosity to specific transport capacity. These data also highlight the resource value of this Salmonella RNA interactome, which will aid in unraveling RNA-centric regulation in enteric pathogens.
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Affiliation(s)
- Gianluca Matera
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Milan Gerovac
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Youssef El Mouali
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), D-97080 Würzburg, Germany
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Jörg Vogel
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany; Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), D-97080 Würzburg, Germany.
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200
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Tsai K, Stojković V, Noda-Garcia L, Young ID, Myasnikov AG, Kleinman J, Palla A, Floor SN, Frost A, Fraser JS, Tawfik DS, Fujimori DG. Directed evolution of the rRNA methylating enzyme Cfr reveals molecular basis of antibiotic resistance. eLife 2022; 11:e70017. [PMID: 35015630 PMCID: PMC8752094 DOI: 10.7554/elife.70017] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/25/2021] [Indexed: 12/11/2022] Open
Abstract
Alteration of antibiotic binding sites through modification of ribosomal RNA (rRNA) is a common form of resistance to ribosome-targeting antibiotics. The rRNA-modifying enzyme Cfr methylates an adenosine nucleotide within the peptidyl transferase center, resulting in the C-8 methylation of A2503 (m8A2503). Acquisition of cfr results in resistance to eight classes of ribosome-targeting antibiotics. Despite the prevalence of this resistance mechanism, it is poorly understood whether and how bacteria modulate Cfr methylation to adapt to antibiotic pressure. Moreover, direct evidence for how m8A2503 alters antibiotic binding sites within the ribosome is lacking. In this study, we performed directed evolution of Cfr under antibiotic selection to generate Cfr variants that confer increased resistance by enhancing methylation of A2503 in cells. Increased rRNA methylation is achieved by improved expression and stability of Cfr through transcriptional and post-transcriptional mechanisms, which may be exploited by pathogens under antibiotic stress as suggested by natural isolates. Using a variant that achieves near-stoichiometric methylation of rRNA, we determined a 2.2 Å cryo-electron microscopy structure of the Cfr-modified ribosome. Our structure reveals the molecular basis for broad resistance to antibiotics and will inform the design of new antibiotics that overcome resistance mediated by Cfr.
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Affiliation(s)
- Kaitlyn Tsai
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Vanja Stojković
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Lianet Noda-Garcia
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Iris D Young
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
| | - Alexander G Myasnikov
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
| | - Jordan Kleinman
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Ali Palla
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
| | - Stephen N Floor
- Helen Diller Family Comprehensive Cancer Center, University of California San FranciscoSan FranciscoUnited States
- Department of Cell and Tissue Biology, University of California San FranciscoSan FranciscoUnited States
| | - Adam Frost
- Department of Biochemistry and Biophysics, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
| | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Danica Galonić Fujimori
- Department of Cellular and Molecular Pharmacology, University of California San FranciscoSan FranciscoUnited States
- Quantitative Biosciences Institute, University of California San FranciscoSan FranciscoUnited States
- Department of Pharmaceutical Chemistry, University of California San FranciscoSan FranciscoUnited States
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