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Cronan JE. Lipoic acid attachment to proteins: stimulating new developments. Microbiol Mol Biol Rev 2024; 88:e0000524. [PMID: 38624243 DOI: 10.1128/mmbr.00005-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
Abstract
SUMMARYLipoic acid-modified proteins are essential for central metabolism and pathogenesis. In recent years, the Escherichia coli and Bacillus subtilis lipoyl assembly pathways have been modified and extended to archaea and diverse eukaryotes including humans. These extensions include a new pathway to insert the key sulfur atoms of lipoate, several new pathways of lipoate salvage, and a novel use of lipoic acid in sulfur-oxidizing bacteria. Other advances are the modification of E. coli LplA for studies of protein localization and protein-protein interactions in cell biology and in enzymatic removal of lipoate from lipoyl proteins. Finally, scenarios have been put forth for the evolution of lipoate assembly in archaea.
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Affiliation(s)
- John E Cronan
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
- Department of Biochemistry, University of Illinois, Urbana, Illinois, USA
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2
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Harasimov K, Gorry RL, Welp LM, Penir SM, Horokhovskyi Y, Cheng S, Takaoka K, Stützer A, Frombach AS, Taylor Tavares AL, Raabe M, Haag S, Saha D, Grewe K, Schipper V, Rizzoli SO, Urlaub H, Liepe J, Schuh M. The maintenance of oocytes in the mammalian ovary involves extreme protein longevity. Nat Cell Biol 2024:10.1038/s41556-024-01442-7. [PMID: 38902423 DOI: 10.1038/s41556-024-01442-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 05/14/2024] [Indexed: 06/22/2024]
Abstract
Women are born with all of their oocytes. The oocyte proteome must be maintained with minimal damage throughout the woman's reproductive life, and hence for decades. Here we report that oocyte and ovarian proteostasis involves extreme protein longevity. Mouse ovaries had more extremely long-lived proteins than other tissues, including brain. These long-lived proteins had diverse functions, including in mitochondria, the cytoskeleton, chromatin and proteostasis. The stable proteins resided not only in oocytes but also in long-lived ovarian somatic cells. Our data suggest that mammals increase protein longevity and enhance proteostasis by chaperones and cellular antioxidants to maintain the female germline for long periods. Indeed, protein aggregation in oocytes did not increase with age and proteasome activity did not decay. However, increasing protein longevity cannot fully block female germline senescence. Large-scale proteome profiling of ~8,890 proteins revealed a decline in many long-lived proteins of the proteostasis network in the aging ovary, accompanied by massive proteome remodeling, which eventually leads to female fertility decline.
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Affiliation(s)
- Katarina Harasimov
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Rebecca L Gorry
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Luisa M Welp
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Sarah Mae Penir
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Yehor Horokhovskyi
- Quantitative and Systems Biology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Shiya Cheng
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Katsuyoshi Takaoka
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Laboratory of Embryology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Alexandra Stützer
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ann-Sophie Frombach
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ana Lisa Taylor Tavares
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
- East Anglian Medical Genetics Service, Cambridge University Hospitals, NHS Foundation Trust, Cambridge, UK
| | - Monika Raabe
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sara Haag
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Translation Alliance Lower Saxony, Hannover, Braunschweig, Göttingen, Germany
| | - Debojit Saha
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Katharina Grewe
- Department for Neuro and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Vera Schipper
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Silvio O Rizzoli
- Department for Neuro and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
- Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany.
- Cluster of Excellence Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells, University of Göttingen, Göttingen, Germany.
| | - Juliane Liepe
- Quantitative and Systems Biology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - Melina Schuh
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
- Cluster of Excellence Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells, University of Göttingen, Göttingen, Germany.
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3
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Ham L, Coomer MA, Öcal K, Grima R, Stumpf MPH. A stochastic vs deterministic perspective on the timing of cellular events. Nat Commun 2024; 15:5286. [PMID: 38902228 PMCID: PMC11190182 DOI: 10.1038/s41467-024-49624-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 06/12/2024] [Indexed: 06/22/2024] Open
Abstract
Cells are the fundamental units of life, and like all life forms, they change over time. Changes in cell state are driven by molecular processes; of these many are initiated when molecule numbers reach and exceed specific thresholds, a characteristic that can be described as "digital cellular logic". Here we show how molecular and cellular noise profoundly influence the time to cross a critical threshold-the first-passage time-and map out scenarios in which stochastic dynamics result in shorter or longer average first-passage times compared to noise-less dynamics. We illustrate the dependence of the mean first-passage time on noise for a set of exemplar models of gene expression, auto-regulatory feedback control, and enzyme-mediated catalysis. Our theory provides intuitive insight into the origin of these effects and underscores two important insights: (i) deterministic predictions for cellular event timing can be highly inaccurate when molecule numbers are within the range known for many cells; (ii) molecular noise can significantly shift mean first-passage times, particularly within auto-regulatory genetic feedback circuits.
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Affiliation(s)
- Lucy Ham
- School of BioSciences, University of Melbourne, Parkville, Australia
- School of Mathematics and Statistics, University of Melbourne, Parkville, Australia
| | - Megan A Coomer
- School of BioSciences, University of Melbourne, Parkville, Australia
- School of Mathematics and Statistics, University of Melbourne, Parkville, Australia
| | - Kaan Öcal
- School of Informatics, University of Edinburgh, Edinburgh, UK
- School of BioSciences, University of Melbourne, Parkville, Australia
| | - Ramon Grima
- School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Michael P H Stumpf
- School of BioSciences, University of Melbourne, Parkville, Australia.
- School of Mathematics and Statistics, University of Melbourne, Parkville, Australia.
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4
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Patel A, McGrosso D, Hefner Y, Campeau A, Sastry AV, Maurya S, Rychel K, Gonzalez DJ, Palsson BO. Proteome allocation is linked to transcriptional regulation through a modularized transcriptome. Nat Commun 2024; 15:5234. [PMID: 38898010 PMCID: PMC11187210 DOI: 10.1038/s41467-024-49231-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
It has proved challenging to quantitatively relate the proteome to the transcriptome on a per-gene basis. Recent advances in data analytics have enabled a biologically meaningful modularization of the bacterial transcriptome. We thus investigate whether matched datasets of transcriptomes and proteomes from bacteria under diverse conditions can be modularized in the same way to reveal novel relationships between their compositions. We find that; (1) the modules of the proteome and the transcriptome are comprised of a similar list of gene products, (2) the modules in the proteome often represent combinations of modules from the transcriptome, (3) known transcriptional and post-translational regulation is reflected in differences between two sets of modules, allowing for knowledge-mapping when interpreting module functions, and (4) through statistical modeling, absolute proteome allocation can be inferred from the transcriptome alone. Quantitative and knowledge-based relationships can thus be found at the genome-scale between the proteome and transcriptome in bacteria.
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Affiliation(s)
- Arjun Patel
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Dominic McGrosso
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ying Hefner
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Anaamika Campeau
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Anand V Sastry
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Svetlana Maurya
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Kevin Rychel
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA
| | - David J Gonzalez
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA.
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800 Kgs, Lyngby, Denmark.
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5
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Chadani Y, Yamanouchi S, Uemura E, Yamasaki K, Niwa T, Ikeda T, Kurihara M, Iwasaki W, Taguchi H. The ABCF proteins in Escherichia coli individually cope with 'hard-to-translate' nascent peptide sequences. Nucleic Acids Res 2024; 52:5825-5840. [PMID: 38661232 PMCID: PMC11162784 DOI: 10.1093/nar/gkae309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 03/18/2024] [Accepted: 04/10/2024] [Indexed: 04/26/2024] Open
Abstract
Organisms possess a wide variety of proteins with diverse amino acid sequences, and their synthesis relies on the ribosome. Empirical observations have led to the misconception that ribosomes are robust protein factories, but in reality, they have several weaknesses. For instance, ribosomes stall during the translation of the proline-rich sequences, but the elongation factor EF-P assists in synthesizing proteins containing the poly-proline sequences. Thus, living organisms have evolved to expand the translation capability of ribosomes through the acquisition of translation elongation factors. In this study, we have revealed that Escherichia coli ATP-Binding Cassette family-F (ABCF) proteins, YheS, YbiT, EttA and Uup, individually cope with various problematic nascent peptide sequences within the exit tunnel. The correspondence between noncanonical translations and ABCFs was YheS for the translational arrest by nascent SecM, YbiT for poly-basic sequence-dependent stalling and poly-acidic sequence-dependent intrinsic ribosome destabilization (IRD), EttA for IRD at the early stage of elongation, and Uup for poly-proline-dependent stalling. Our results suggest that ATP hydrolysis-coupled structural rearrangement and the interdomain linker sequence are pivotal for handling 'hard-to-translate' nascent peptides. Our study highlights a new aspect of ABCF proteins to reduce the potential risks that are encoded within the nascent peptide sequences.
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Affiliation(s)
- Yuhei Chadani
- Faculty of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Shun Yamanouchi
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Eri Uemura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Kohei Yamasaki
- Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Tatsuya Niwa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Toma Ikeda
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Miku Kurihara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Wataru Iwasaki
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Kashiwa, Chiba 277-0882, Japan
| | - Hideki Taguchi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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6
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Munro V, Kelly V, Messner CB, Kustatscher G. Cellular control of protein levels: A systems biology perspective. Proteomics 2024; 24:e2200220. [PMID: 38012370 DOI: 10.1002/pmic.202200220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023]
Abstract
How cells regulate protein levels is a central question of biology. Over the past decades, molecular biology research has provided profound insights into the mechanisms and the molecular machinery governing each step of the gene expression process, from transcription to protein degradation. Recent advances in transcriptomics and proteomics have complemented our understanding of these fundamental cellular processes with a quantitative, systems-level perspective. Multi-omic studies revealed significant quantitative, kinetic and functional differences between the genome, transcriptome and proteome. While protein levels often correlate with mRNA levels, quantitative investigations have demonstrated a substantial impact of translation and protein degradation on protein expression control. In addition, protein-level regulation appears to play a crucial role in buffering protein abundances against undesirable mRNA expression variation. These findings have practical implications for many fields, including gene function prediction and precision medicine.
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Affiliation(s)
- Victoria Munro
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Van Kelly
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Christoph B Messner
- Precision Proteomics Center, Swiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, Davos, Switzerland
| | - Georg Kustatscher
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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7
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Reddien PW. The purpose and ubiquity of turnover. Cell 2024; 187:2657-2681. [PMID: 38788689 DOI: 10.1016/j.cell.2024.04.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/19/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
Turnover-constant component production and destruction-is ubiquitous in biology. Turnover occurs across organisms and scales, including for RNAs, proteins, membranes, macromolecular structures, organelles, cells, hair, feathers, nails, antlers, and teeth. For many systems, turnover might seem wasteful when degraded components are often fully functional. Some components turn over with shockingly high rates and others do not turn over at all, further making this process enigmatic. However, turnover can address fundamental problems by yielding powerful properties, including regeneration, rapid repair onset, clearance of unpredictable damage and errors, maintenance of low constitutive levels of disrepair, prevention of stable hazards, and transitions. I argue that trade-offs between turnover benefits and metabolic costs, combined with constraints on turnover, determine its presence and rates across distinct contexts. I suggest that the limits of turnover help explain aging and that turnover properties and the basis for its levels underlie this fundamental component of life.
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Affiliation(s)
- Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02139, USA.
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8
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Zhu M, Dai X. Shaping of microbial phenotypes by trade-offs. Nat Commun 2024; 15:4238. [PMID: 38762599 PMCID: PMC11102524 DOI: 10.1038/s41467-024-48591-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 05/06/2024] [Indexed: 05/20/2024] Open
Abstract
Growth rate maximization is an important fitness strategy for microbes. However, the wide distribution of slow-growing oligotrophic microbes in ecosystems suggests that rapid growth is often not favored across ecological environments. In many circumstances, there exist trade-offs between growth and other important traits (e.g., adaptability and survival) due to physiological and proteome constraints. Investments on alternative traits could compromise growth rate and microbes need to adopt bet-hedging strategies to improve fitness in fluctuating environments. Here we review the mechanistic role of trade-offs in controlling bacterial growth and further highlight its ecological implications in driving the emergences of many important ecological phenomena such as co-existence, population heterogeneity and oligotrophic/copiotrophic lifestyles.
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Affiliation(s)
- Manlu Zhu
- State Key Laboratory of Green Pesticide, School of Life Sciences, Central China Normal University, Wuhan, PR China
| | - Xiongfeng Dai
- State Key Laboratory of Green Pesticide, School of Life Sciences, Central China Normal University, Wuhan, PR China.
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9
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Wang M, Zhang L, Yang H, Lu H. Translatome and transcriptome profiling of neonatal mice hippocampus exposed to sevoflurane anesthesia. Heliyon 2024; 10:e28876. [PMID: 38707353 PMCID: PMC11066607 DOI: 10.1016/j.heliyon.2024.e28876] [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: 03/21/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 05/07/2024] Open
Abstract
Exposure to anesthesia in early life may cause severe damage to the brain and lead to cognitive impairment. The underlying mechanisms, which have only been investigated in a limited scale, remains largely elusive. We performed translatome and transcriptome sequencing together for the first time in hippocampus of neonatal mice that were exposed to sevoflurane. We treated a group of neonatal mice with 2.5 % sevoflurane for 2 h on day 6, 7, 8, 9 and treated another group on day 6, 7. We performed behavioral study after day 30 for both groups and the control to evaluate the cognitive impairment. On day 36, we collected translatome and transcriptome from the hippocampus in the two groups, compared the gene expression levels between the groups and the control, and validated the results with RT-qPCR. We identified 1750 differentially expressed genes (DEGs) from translatome comparison and 1109 DEGs from transcriptome comparison. As expected, translatome-based DEGs significantly overlapped with transcriptome-based DEGs, and functional enrichment analysis generated similar enriched cognition-related GO terms and KEGG pathways. However, for many genes like Hspa5, their alterations in translatome differed remarkably from those in transcriptome, and Western blot results were largely concordant with the former, suggesting that translational regulation plays a significant role in cellular response to sevoflurane. Our study revealed global alterations in translatome and transcriptome of mice hippocampus after neonatal exposure to sevoflurane anesthesia and highlighted the importance of translatome analysis in understanding the mechanisms responsible for anesthesia-induced cognitive impairment.
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Affiliation(s)
- Menghan Wang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Limin Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Hecheng Yang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Hong Lu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
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10
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Cho THS, Murray C, Malpica R, Margain-Quevedo R, Thede GL, Lu J, Edwards RA, Glover JNM, Raivio TL. The sensor of the bacterial histidine kinase CpxA is a novel dimer of extracytoplasmic Per-ARNT-Sim domains. J Biol Chem 2024; 300:107265. [PMID: 38582452 PMCID: PMC11078701 DOI: 10.1016/j.jbc.2024.107265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 03/17/2024] [Accepted: 03/29/2024] [Indexed: 04/08/2024] Open
Abstract
Histidine kinases are key bacterial sensors that recognize diverse environmental stimuli. While mechanisms of phosphorylation and phosphotransfer by cytoplasmic kinase domains are relatively well-characterized, the ways in which extracytoplasmic sensor domains regulate activation remain mysterious. The Cpx envelope stress response is a conserved Gram-negative two-component system which is controlled by the sensor kinase CpxA. We report the structure of the Escherichia coli CpxA sensor domain (CpxA-SD) as a globular Per-ARNT-Sim (PAS)-like fold highly similar to that of Vibrio parahaemolyticus CpxA as determined by X-ray crystallography. Because sensor kinase dimerization is important for signaling, we used AlphaFold2 to model CpxA-SD in the context of its connected transmembrane domains, which yielded a novel dimer of PAS domains possessing a distinct dimer organization compared to previously characterized sensor domains. Gain of function cpxA∗ alleles map to the dimer interface, and mutation of other residues in this region also leads to constitutive activation. CpxA activation can be suppressed by mutations that restore inter-monomer interactions, suggesting that inhibitory interactions between CpxA-SD monomers are the major point of control for CpxA activation and signaling. Searching through hundreds of structural homologs revealed the sensor domain of Pseudomonas aeruginosa sensor kinase PfeS as the only PAS structure in the same novel dimer orientation as CpxA, suggesting that our dimer orientation may be utilized by other extracytoplasmic PAS domains. Overall, our findings provide insight into the diversity of the organization of PAS sensory domains and how they regulate sensor kinase activation.
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Affiliation(s)
- Timothy H S Cho
- Departments of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Cameron Murray
- Departments of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Roxana Malpica
- Departments of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada; Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Chihuahua, México
| | | | - Gina L Thede
- Departments of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jun Lu
- Departments of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada; Departments of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ross A Edwards
- Departments of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - J N Mark Glover
- Departments of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Tracy L Raivio
- Departments of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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11
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MacNair CR, Rutherford ST, Tan MW. Alternative therapeutic strategies to treat antibiotic-resistant pathogens. Nat Rev Microbiol 2024; 22:262-275. [PMID: 38082064 DOI: 10.1038/s41579-023-00993-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2023] [Indexed: 04/19/2024]
Abstract
Resistance threatens to render antibiotics - which are essential for modern medicine - ineffective, thus posing a threat to human health. The discovery of novel classes of antibiotics able to overcome resistance has been stalled for decades, with the developmental pipeline relying almost entirely on variations of existing chemical scaffolds. Unfortunately, this approach has been unable to keep pace with resistance evolution, necessitating new therapeutic strategies. In this Review, we highlight recent efforts to discover non-traditional antimicrobials, specifically describing the advantages and limitations of antimicrobial peptides and macrocycles, antibodies, bacteriophages and antisense oligonucleotides. These approaches have the potential to stem the tide of resistance by expanding the physicochemical property space and target spectrum occupied by currently approved antibiotics.
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Affiliation(s)
- Craig R MacNair
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA
| | - Steven T Rutherford
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech Inc., South San Francisco, CA, USA.
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12
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Shu S, Tsutsui Y, Nathawat R, Mi W. Dual function of LapB (YciM) in regulating Escherichia coli lipopolysaccharide synthesis. Proc Natl Acad Sci U S A 2024; 121:e2321510121. [PMID: 38635633 PMCID: PMC11046580 DOI: 10.1073/pnas.2321510121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/21/2024] [Indexed: 04/20/2024] Open
Abstract
Levels of lipopolysaccharide (LPS), an essential glycolipid on the surface of most gram-negative bacteria, are tightly controlled-making LPS synthesis a promising target for developing new antibiotics. Escherichia coli adaptor protein LapB (YciM) plays an important role in regulating LPS synthesis by promoting degradation of LpxC, a deacetylase that catalyzes the first committed step in LPS synthesis. Under conditions where LPS is abundant, LapB recruits LpxC to the AAA+ protease FtsH for degradation. LapB achieves this by simultaneously interacting with FtsH through its transmembrane helix and LpxC through its cytoplasmic domain. Here, we describe a cryo-EM structure of the complex formed between LpxC and the cytoplasmic domain of LapB (LapBcyto). The structure reveals how LapB exploits both its tetratricopeptide repeat (TPR) motifs and rubredoxin domain to interact with LpxC. Through both in vitro and in vivo analysis, we show that mutations at the LapBcyto/LpxC interface prevent LpxC degradation. Unexpectedly, binding to LapBcyto also inhibits the enzymatic activity of LpxC through allosteric effects reminiscent of LpxC activation by MurA in Pseudomonas aeruginosa. Our findings argue that LapB regulates LPS synthesis in two steps: In the first step, LapB inhibits the activity of LpxC, and in the second step, it commits LpxC to degradation by FtsH.
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Affiliation(s)
- Sheng Shu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Yuko Tsutsui
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
- Cancer Biology Institute, Yale University, West Haven, CT06516
| | - Rajkanwar Nathawat
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Wei Mi
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06520
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13
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Frese AN, Mariossi A, Levine MS, Wühr M. Quantitative proteome dynamics across embryogenesis in a model chordate. iScience 2024; 27:109355. [PMID: 38510129 PMCID: PMC10951915 DOI: 10.1016/j.isci.2024.109355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/11/2023] [Accepted: 02/23/2024] [Indexed: 03/22/2024] Open
Abstract
The evolution of gene expression programs underlying the development of vertebrates remains poorly characterized. Here, we present a comprehensive proteome atlas of the model chordate Ciona, covering eight developmental stages and ∼7,000 translated genes, accompanied by a multi-omics analysis of co-evolution with the vertebrate Xenopus. Quantitative proteome comparisons argue against the widely held hourglass model, based solely on transcriptomic profiles, whereby peak conservation is observed during mid-developmental stages. Our analysis reveals maximal divergence at these stages, particularly gastrulation and neurulation. Together, our work provides a valuable resource for evaluating conservation and divergence of multi-omics profiles underlying the diversification of vertebrates.
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Affiliation(s)
- Alexander N. Frese
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Andrea Mariossi
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Michael S. Levine
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Martin Wühr
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
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14
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McShane E, Couvillion M, Ietswaart R, Prakash G, Smalec BM, Soto I, Baxter-Koenigs AR, Choquet K, Churchman LS. A kinetic dichotomy between mitochondrial and nuclear gene expression processes. Mol Cell 2024; 84:1541-1555.e11. [PMID: 38503286 DOI: 10.1016/j.molcel.2024.02.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/12/2023] [Accepted: 02/27/2024] [Indexed: 03/21/2024]
Abstract
Oxidative phosphorylation (OXPHOS) complexes, encoded by both mitochondrial and nuclear DNA, are essential producers of cellular ATP, but how nuclear and mitochondrial gene expression steps are coordinated to achieve balanced OXPHOS subunit biogenesis remains unresolved. Here, we present a parallel quantitative analysis of the human nuclear and mitochondrial messenger RNA (mt-mRNA) life cycles, including transcript production, processing, ribosome association, and degradation. The kinetic rates of nearly every stage of gene expression differed starkly across compartments. Compared with nuclear mRNAs, mt-mRNAs were produced 1,100-fold more, degraded 7-fold faster, and accumulated to 160-fold higher levels. Quantitative modeling and depletion of mitochondrial factors LRPPRC and FASTKD5 identified critical points of mitochondrial regulatory control, revealing that the mitonuclear expression disparities intrinsically arise from the highly polycistronic nature of human mitochondrial pre-mRNA. We propose that resolving these differences requires a 100-fold slower mitochondrial translation rate, illuminating the mitoribosome as a nexus of mitonuclear co-regulation.
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Affiliation(s)
- Erik McShane
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Mary Couvillion
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Robert Ietswaart
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Gyan Prakash
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Brendan M Smalec
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Iliana Soto
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Autum R Baxter-Koenigs
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Karine Choquet
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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15
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Kim S, Wang YH, Hassan A, Kim S. Re-defining how mRNA degradation is coordinated with transcription and translation in bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.588412. [PMID: 38659903 PMCID: PMC11042359 DOI: 10.1101/2024.04.18.588412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
In eukaryotic cells, transcription, translation, and mRNA degradation occur in distinct subcellular regions. How these mRNA processes are organized in bacteria, without employing membrane-bound compartments, remains unclear. Here, we present generalizable principles underlying coordination between these processes in bacteria. In Escherichia coli, we found that co-transcriptional degradation is rare for mRNAs except for those encoding inner membrane proteins, due to membrane localization of the main ribonuclease, RNase E. We further found, by varying ribosome binding sequences, that translation affects mRNA stability not because ribosomes protect mRNA from degradation, but because low translation leads to premature transcription termination in the absence of transcription-translation coupling. Extending our analyses to Bacillus subtilis and Caulobacter crescentus, we established subcellular localization of RNase E (or its homolog) and premature transcription termination in the absence of transcription-translation coupling as key determinants that explain differences in transcriptional and translational coupling to mRNA degradation across genes and species.
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Affiliation(s)
- Seunghyeon Kim
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yu-Huan Wang
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Albur Hassan
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sangjin Kim
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana–Champaign, Urbana, IL 61801, USA
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16
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Nguyen TN, Ingle C, Thompson S, Reynolds KA. The genetic landscape of a metabolic interaction. Nat Commun 2024; 15:3351. [PMID: 38637543 PMCID: PMC11026382 DOI: 10.1038/s41467-024-47671-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 04/09/2024] [Indexed: 04/20/2024] Open
Abstract
While much prior work has explored the constraints on protein sequence and evolution induced by physical protein-protein interactions, the sequence-level constraints emerging from non-binding functional interactions in metabolism remain unclear. To quantify how variation in the activity of one enzyme constrains the biochemical parameters and sequence of another, we focus on dihydrofolate reductase (DHFR) and thymidylate synthase (TYMS), a pair of enzymes catalyzing consecutive reactions in folate metabolism. We use deep mutational scanning to quantify the growth rate effect of 2696 DHFR single mutations in 3 TYMS backgrounds under conditions selected to emphasize biochemical epistasis. Our data are well-described by a relatively simple enzyme velocity to growth rate model that quantifies how metabolic context tunes enzyme mutational tolerance. Together our results reveal the structural distribution of epistasis in a metabolic enzyme and establish a foundation for the design of multi-enzyme systems.
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Affiliation(s)
- Thuy N Nguyen
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- The Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- The Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Form Bio, Dallas, TX, 75226, USA
| | - Christine Ingle
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- The Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- The Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Samuel Thompson
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, 94158, USA
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
| | - Kimberly A Reynolds
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- The Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- The Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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17
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Ferrero-Bordera B, Bartel J, van Dijl JM, Becher D, Maaß S. From the outer space to the inner cell: deconvoluting the complexity of Bacillus subtilis disulfide stress responses by redox state and absolute abundance quantification of extracellular, membrane, and cytosolic proteins. Microbiol Spectr 2024; 12:e0261623. [PMID: 38358275 PMCID: PMC10986503 DOI: 10.1128/spectrum.02616-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/22/2024] [Indexed: 02/16/2024] Open
Abstract
Understanding cellular mechanisms of stress management relies on omics data as a valuable resource. However, the lack of absolute quantitative data on protein abundances remains a significant limitation, particularly when comparing protein abundances across different cell compartments. In this study, we aimed to gain deeper insights into the proteomic responses of the Gram-positive model bacterium Bacillus subtilis to disulfide stress. We determined proteome-wide absolute abundances, focusing on different sub-cellular locations (cytosol and membrane) as well as the extracellular medium, and combined these data with redox state determination. To quantify secreted proteins in the culture medium, we developed a simple and straightforward protocol for the absolute quantification of extracellular proteins in bacteria. We concentrated extracellular proteins, which are highly diluted in the medium, using StrataClean beads along with a set of standard proteins to determine the extent of the concentration step. The resulting data set provides new insights into protein abundances in different sub-cellular compartments and the extracellular medium, along with a comprehensive proteome-wide redox state determination. Our study offers a quantitative understanding of disulfide stress management, protein production, and secretion in B. subtilis. IMPORTANCE Stress responses play a crucial role in bacterial survival and adaptation. The ability to quantitatively measure protein abundances and redox states in different cellular compartments and the extracellular environment is essential for understanding stress management mechanisms. In this study, we addressed the knowledge gap regarding absolute quantification of extracellular proteins and compared protein concentrations in various sub-cellular locations and in the extracellular medium under disulfide stress conditions. Our findings provide valuable insights into the protein production and secretion dynamics of B. subtilis, shedding light on its stress response strategies. Furthermore, the developed protocol for absolute quantification of extracellular proteins in bacteria presents a practical and efficient approach for future studies in the field. Overall, this research contributes to the quantitative understanding of stress management mechanisms and protein dynamics in B. subtilis, which can be used to enhance bacterial stress tolerance and protein-based biotechnological applications.
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Affiliation(s)
- Borja Ferrero-Bordera
- Department of Microbial Proteomics, University of Greifswald, Centre of Functional Genomics of Microbes, Institute of Microbiology, Greifswald, Germany
| | - Jürgen Bartel
- Department of Microbial Proteomics, University of Greifswald, Centre of Functional Genomics of Microbes, Institute of Microbiology, Greifswald, Germany
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Dörte Becher
- Department of Microbial Proteomics, University of Greifswald, Centre of Functional Genomics of Microbes, Institute of Microbiology, Greifswald, Germany
| | - Sandra Maaß
- Department of Microbial Proteomics, University of Greifswald, Centre of Functional Genomics of Microbes, Institute of Microbiology, Greifswald, Germany
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18
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Tian M, Kawaguchi R, Shen Y, Machnicki M, Villegas NG, Cooper DR, Montgomery N, Haring J, Lan R, Yuan AH, Williams CK, Magaki S, Vinters HV, Zhang Y, De Biase LM, Silva AJ, Carmichael ST. Intercellular Signaling Pathways as Therapeutic Targets for Vascular Dementia Repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.24.585301. [PMID: 38585718 PMCID: PMC10996514 DOI: 10.1101/2024.03.24.585301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Vascular dementia (VaD) is a white matter ischemic disease and the second-leading cause of dementia, with no direct therapy. Within the lesion site, cell-cell interactions dictate the trajectory towards disease progression or repair. To elucidate the underlying intercellular signaling pathways, a VaD mouse model was developed for transcriptomic and functional studies. The mouse VaD transcriptome was integrated with a human VaD snRNA-Seq dataset. A custom-made database encompassing 4053 human and 2032 mouse ligand-receptor (L-R) interactions identified significantly altered pathways shared between human and mouse VaD. Two intercellular L-R systems, Serpine2-Lrp1 and CD39-A3AR, were selected for mechanistic study as both the ligand and receptor were dysregulated in VaD. Decreased Seprine2 expression enhances OPC differentiation in VaD repair. A clinically relevant drug that reverses the loss of CD39-A3AR function promotes tissue and behavioral recovery in the VaD model. This study presents novel intercellular signaling targets and may open new avenues for VaD therapies.
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19
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Tao K, Narita SI, Okada U, Murakami S, Tokuda H. Dissection of an ABC transporter LolCDE function analyzed by photo-crosslinking. J Biochem 2024; 175:427-437. [PMID: 38156779 PMCID: PMC11005994 DOI: 10.1093/jb/mvad118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 12/15/2023] [Indexed: 01/03/2024] Open
Abstract
The envelope of Escherichia coli contains approximately 100 different species of lipoproteins, most of which are localized to the inner leaflet of the outer membrane. The localization of lipoprotein (Lol) system, consisting of five Lol proteins, is responsible for the trafficking of lipoproteins to the outer membrane. LolCDE binds to lipoproteins destined for the outer membrane and transfers them to the periplasmic chaperone LolA. Although the cryo-EM structures of E. coli LolCDE have been reported, the mechanisms by which outer membrane lipoproteins are transferred to LolA remain elusive. In this study, we investigated the interaction between LolCDE and lipoproteins using site-specific photo-crosslinking. We introduced a photo-crosslinkable amino acid into different locations across the four helices which form the central lipoprotein-binding cavity, and identified domains that crosslink with peptidoglycan-associated lipoprotein (Pal) in vivo. Using one of the derivatives containing the photo-crosslinkable amino acid, we developed an in vitro system to analyze the binding of lipoproteins to LolCDE. Our results indicate that compound 2, a LolCDE inhibitor, does not inhibit the binding of lipoproteins to LolCDE, but rather promotes the dissociation of bound lipoproteins from LolCDE.
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Affiliation(s)
- Kazuyuki Tao
- Isotope Science Center, University of Tokyo, 2-11-16 Yayoi, Bunky-ku, Tokyo 113-0032, Japan
| | - Shin-ichiro Narita
- Faculty of Health and Nutrition, Yamagata Prefectural Yonezawa University of Nutrition Sciences, Yonezawa, Yamagata 992-0025, Japan
| | - Ui Okada
- Department of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Satoshi Murakami
- Department of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama 226-8501, Japan
| | - Hajime Tokuda
- Faculty of Nutritional Sciences, University of Morioka, Takizawa, Iwate 020-0694, Japan
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20
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Kuzminov A. Bacterial nucleoid is a riddle wrapped in a mystery inside an enigma. J Bacteriol 2024; 206:e0021123. [PMID: 38358278 PMCID: PMC10994824 DOI: 10.1128/jb.00211-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024] Open
Abstract
Bacterial chromosome, the nucleoid, is traditionally modeled as a rosette of DNA mega-loops, organized around proteinaceous central scaffold by nucleoid-associated proteins (NAPs), and mixed with the cytoplasm by transcription and translation. Electron microscopy of fixed cells confirms dispersal of the cloud-like nucleoid within the ribosome-filled cytoplasm. Here, I discuss evidence that the nucleoid in live cells forms DNA phase separate from riboprotein phase, the "riboid." I argue that the nucleoid-riboid interphase, where DNA interacts with NAPs, transcribing RNA polymerases, nascent transcripts, and ssRNA chaperones, forms the transcription zone. An active part of phase separation, transcription zone enforces segregation of the centrally positioned information phase (the nucleoid) from the surrounding action phase (the riboid), where translation happens, protein accumulates, and metabolism occurs. I speculate that HU NAP mostly tiles up the nucleoid periphery-facilitating DNA mobility but also supporting transcription in the interphase. Besides extruding plectonemically supercoiled DNA mega-loops, condensins could compact them into solenoids of uniform rings, while HU could support rigidity and rotation of these DNA rings. The two-phase cytoplasm arrangement allows the bacterial cell to organize the central dogma activities, where (from the cell center to its periphery) DNA replicates and segregates, DNA is transcribed, nascent mRNA is handed over to ribosomes, mRNA is translated into proteins, and finally, the used mRNA is recycled into nucleotides at the inner membrane. The resulting information-action conveyor, with one activity naturally leading to the next one, explains the efficiency of prokaryotic cell design-even though its main intracellular transportation mode is free diffusion.
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Affiliation(s)
- Andrei Kuzminov
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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21
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Teyssonniere EM, Shichino Y, Mito M, Friedrich A, Iwasaki S, Schacherer J. Translation variation across genetic backgrounds reveals a post-transcriptional buffering signature in yeast. Nucleic Acids Res 2024; 52:2434-2445. [PMID: 38261993 PMCID: PMC10954453 DOI: 10.1093/nar/gkae030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 12/21/2023] [Accepted: 01/11/2024] [Indexed: 01/25/2024] Open
Abstract
Gene expression is known to vary among individuals, and this variability can impact the phenotypic diversity observed in natural populations. While the transcriptome and proteome have been extensively studied, little is known about the translation process itself. Here, we therefore performed ribosome and transcriptomic profiling on a genetically and ecologically diverse set of natural isolates of the Saccharomyces cerevisiae yeast. Interestingly, we found that the Euclidean distances between each profile and the expression fold changes in each pairwise isolate comparison were higher at the transcriptomic level. This observation clearly indicates that the transcriptional variation observed in the different isolates is buffered through a phenomenon known as post-transcriptional buffering at the translation level. Furthermore, this phenomenon seemed to have a specific signature by preferentially affecting essential genes as well as genes involved in complex-forming proteins, and low transcribed genes. We also explored the translation of the S. cerevisiae pangenome and found that the accessory genes related to introgression events displayed similar transcription and translation levels as the core genome. By contrast, genes acquired through horizontal gene transfer events tended to be less efficiently translated. Together, our results highlight both the extent and signature of the post-transcriptional buffering.
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Affiliation(s)
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Mari Mito
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Anne Friedrich
- Université de Strasbourg, CNRS, GMGM UMR, 7156 Strasbourg, France
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Joseph Schacherer
- Université de Strasbourg, CNRS, GMGM UMR, 7156 Strasbourg, France
- Institut Universitaire de France (IUF), Paris, France
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22
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Sun G, DeFelice MM, Gillies TE, Ahn-Horst TA, Andrews CJ, Krummenacker M, Karp PD, Morrison JH, Covert MW. Cross-evaluation of E. coli's operon structures via a whole-cell model suggests alternative cellular benefits for low- versus high-expressing operons. Cell Syst 2024; 15:227-245.e7. [PMID: 38417437 PMCID: PMC10957310 DOI: 10.1016/j.cels.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/12/2023] [Accepted: 02/08/2024] [Indexed: 03/01/2024]
Abstract
Many bacteria use operons to coregulate genes, but it remains unclear how operons benefit bacteria. We integrated E. coli's 788 polycistronic operons and 1,231 transcription units into an existing whole-cell model and found inconsistencies between the proposed operon structures and the RNA-seq read counts that the model was parameterized from. We resolved these inconsistencies through iterative, model-guided corrections to both datasets, including the correction of RNA-seq counts of short genes that were misreported as zero by existing alignment algorithms. The resulting model suggested two main modes by which operons benefit bacteria. For 86% of low-expression operons, adding operons increased the co-expression probabilities of their constituent proteins, whereas for 92% of high-expression operons, adding operons resulted in more stable expression ratios between the proteins. These simulations underscored the need for further experimental work on how operons reduce noise and synchronize both the expression timing and the quantity of constituent genes. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Gwanggyu Sun
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Mialy M DeFelice
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Taryn E Gillies
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Travis A Ahn-Horst
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Cecelia J Andrews
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Jerry H Morrison
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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23
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Gh. MS, Wilhelm MJ, Dai HL. Observing mechanosensitive channels in action in living bacteria. BIOPHYSICAL REPORTS 2024; 4:100141. [PMID: 38189030 PMCID: PMC10765490 DOI: 10.1016/j.bpr.2023.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/07/2023] [Indexed: 01/09/2024]
Abstract
Mechanosensitive (MS) channels act to protect the cytoplasmic membrane (CM) of living cells from environmental changes in osmolarity. In this report, we demonstrate the use of time-resolved second-harmonic light scattering (SHS) as a means of experimentally observing the relative state (open versus closed) of MS channels in living bacteria suspended in different buffer solutions. Specifically, the state of the MS channels was selectively controlled by changing the composition of the suspension medium, inducing either a transient or persistent osmotic shock. SHS was then used to monitor transport of the SHG-active cation, malachite green, across the bacterial CM. When MS channels were forced open, malachite green cations were able to cross the CM at a rate at least two orders of magnitude faster compared with when the MS channels were closed. These observations were corroborated using both numerical model simulations and complementary fluorescence experiments, in which the propensity for the CM impermeant cation, propidium, to stain cells was shown to be contingent upon the relative state of the MS channels (i.e., cells with open MS channels fluoresced red, cells with closed MS channels did not). Application of time-resolved SHS to experimentally distinguish MS channels opened via osmotic shock versus chemical activation, as well as a general comparison with the patch-clamp method is discussed.
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Affiliation(s)
| | | | - Hai-Lung Dai
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania
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24
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Baghdassarian HM, Lewis NE. Resource allocation in mammalian systems. Biotechnol Adv 2024; 71:108305. [PMID: 38215956 PMCID: PMC11182366 DOI: 10.1016/j.biotechadv.2023.108305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/14/2024]
Abstract
Cells execute biological functions to support phenotypes such as growth, migration, and secretion. Complementarily, each function of a cell has resource costs that constrain phenotype. Resource allocation by a cell allows it to manage these costs and optimize their phenotypes. In fact, the management of resource constraints (e.g., nutrient availability, bioenergetic capacity, and macromolecular machinery production) shape activity and ultimately impact phenotype. In mammalian systems, quantification of resource allocation provides important insights into higher-order multicellular functions; it shapes intercellular interactions and relays environmental cues for tissues to coordinate individual cells to overcome resource constraints and achieve population-level behavior. Furthermore, these constraints, objectives, and phenotypes are context-dependent, with cells adapting their behavior according to their microenvironment, resulting in distinct steady-states. This review will highlight the biological insights gained from probing resource allocation in mammalian cells and tissues.
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Affiliation(s)
- Hratch M Baghdassarian
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nathan E Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA.
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25
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Soubrier C, Foxall E, Ciandrini L, Dao Duc K. Optimal control of ribosome population for gene expression under periodic nutrient intake. J R Soc Interface 2024; 21:20230652. [PMID: 38442858 PMCID: PMC10914516 DOI: 10.1098/rsif.2023.0652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/05/2024] [Indexed: 03/07/2024] Open
Abstract
Translation of proteins is a fundamental part of gene expression that is mediated by ribosomes. As ribosomes significantly contribute to both cellular mass and energy consumption, achieving efficient management of the ribosome population is also crucial to metabolism and growth. Inspired by biological evidence for nutrient-dependent mechanisms that control both ribosome-active degradation and genesis, we introduce a dynamical model of protein production, that includes the dynamics of resources and control over the ribosome population. Under the hypothesis that active degradation and biogenesis are optimal for maximizing and maintaining protein production, we aim to qualitatively reproduce empirical observations of the ribosome population dynamics. Upon formulating the associated optimization problem, we first analytically study the stability and global behaviour of solutions under constant resource input, and characterize the extent of oscillations and convergence rate to a global equilibrium. We further use these results to simplify and solve the problem under a quasi-static approximation. Using biophysical parameter values, we find that optimal control solutions lead to both control mechanisms and the ribosome population switching between periods of feeding and fasting, suggesting that the intense regulation of ribosome population observed in experiments allows to maximize and maintain protein production. Finally, we find some range for the control values over which such a regime can be observed, depending on the intensity of fasting.
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Affiliation(s)
- Clément Soubrier
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Eric Foxall
- Department of Mathematics, University of British Columbia Okanagan, Kelowna, British Columbia, Canada V1V 1V7
| | - Luca Ciandrini
- Centre de Biochimie Structurale (CBS), INSERM U154, CNRS UMR5048, University of Montpellier, Montpellier, France
- Institut Universitaire de France (IUF), Paris, France
| | - Khanh Dao Duc
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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26
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Otto RM, Turska-Nowak A, Brown PM, Reynolds KA. A continuous epistasis model for predicting growth rate given combinatorial variation in gene expression and environment. Cell Syst 2024; 15:134-148.e7. [PMID: 38340730 PMCID: PMC10885703 DOI: 10.1016/j.cels.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/13/2023] [Accepted: 01/18/2024] [Indexed: 02/12/2024]
Abstract
Quantifying and predicting growth rate phenotype given variation in gene expression and environment is complicated by epistatic interactions and the vast combinatorial space of possible perturbations. We developed an approach for mapping expression-growth rate landscapes that integrates sparsely sampled experimental measurements with an interpretable machine learning model. We used mismatch CRISPRi across pairs and triples of genes to create over 8,000 titrated changes in E. coli gene expression under varied environmental contexts, exploring epistasis in up to 22 distinct environments. Our results show that a pairwise model previously used to describe drug interactions well-described these data. The model yielded interpretable parameters related to pathway architecture and generalized to predict the combined effect of up to four perturbations when trained solely on pairwise perturbation data. We anticipate this approach will be broadly applicable in optimizing bacterial growth conditions, generating pharmacogenomic models, and understanding the fundamental constraints on bacterial gene expression. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Ryan M Otto
- Green Center for Systems Biology - Lyda Hill Department of Bioinformatics, The University of Texas Southwestern Medical Center, Dallas, TX 75230, USA
| | - Agata Turska-Nowak
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75230, USA
| | - Philip M Brown
- Green Center for Systems Biology - Lyda Hill Department of Bioinformatics, The University of Texas Southwestern Medical Center, Dallas, TX 75230, USA
| | - Kimberly A Reynolds
- Green Center for Systems Biology - Lyda Hill Department of Bioinformatics, The University of Texas Southwestern Medical Center, Dallas, TX 75230, USA; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75230, USA.
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27
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Leavitt RJ, Almeida A, Grilj V, Montay-Gruel P, Godfroid C, Petit B, Bailat C, Limoli CL, Vozenin MC. Acute Hypoxia Does Not Alter Tumor Sensitivity to FLASH Radiation Therapy. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00320-1. [PMID: 38387809 DOI: 10.1016/j.ijrobp.2024.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/10/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE Tumor hypoxia is a major cause of treatment resistance, especially to radiation therapy at conventional dose rate (CONV), and we wanted to assess whether hypoxia does alter tumor sensitivity to FLASH. METHODS AND MATERIALS We engrafted several tumor types (glioblastoma [GBM], head and neck cancer, and lung adenocarcinoma) subcutaneously in mice to provide a reliable and rigorous way to modulate oxygen supply via vascular clamping or carbogen breathing. We irradiated tumors using a single 20-Gy fraction at either CONV or FLASH, measured oxygen tension, monitored tumor growth, and sampled tumors for bulk RNAseq and pimonidazole analysis. Next, we inhibited glycolysis with trametinib in GBM tumors to enhance FLASH efficacy. RESULTS Using various subcutaneous tumor models, and in contrast to CONV, FLASH retained antitumor efficacy under acute hypoxia. These findings show that in addition to normal tissue sparing, FLASH could overcome hypoxia-mediated tumor resistance. Follow-up molecular analysis using RNAseq profiling uncovered a FLASH-specific profile in human GBM that involved cell-cycle arrest, decreased ribosomal biogenesis, and a switch from oxidative phosphorylation to glycolysis. Glycolysis inhibition by trametinib enhanced FLASH efficacy in both normal and clamped conditions. CONCLUSIONS These data provide new and specific insights showing the efficacy of FLASH in a radiation-resistant context, proving an additional benefit of FLASH over CONV.
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Affiliation(s)
- Ron J Leavitt
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Aymeric Almeida
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Pierre Montay-Gruel
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland; Radiation Oncology Department, Iridium Netwerk, Wilrijk (Antwerp), Belgium; Antwerp Research in Radiation Oncology (AReRO), Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Céline Godfroid
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Benoit Petit
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, California
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland.
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28
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Zhu M, Mu H, Dai X. Integrated control of bacterial growth and stress response by (p)ppGpp in Escherichia coli: A seesaw fashion. iScience 2024; 27:108818. [PMID: 38299113 PMCID: PMC10828813 DOI: 10.1016/j.isci.2024.108818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/02/2023] [Accepted: 01/02/2024] [Indexed: 02/02/2024] Open
Abstract
To thrive in nature, bacteria have to reproduce efficiently under favorable conditions and persist during stress. The global strategy that integrates the growth control and stress response remains to be explored. Here, we find that a moderate induction of (p)ppGpp reduces growth rate but significantly enhances the stress tolerance of E. coli, resulting from a global resource re-allocation from ribosome synthesis to the synthesis of stress-responsive proteins. Strikingly, the activation of stress response by (p)ppGpp is still largely retained in the absence of RpoS. In addition, (p)ppGpp induction could activate the catabolism of alanine and arginine, facilitating the adaption of bacteria to nutrient downshift. Our work demonstrates that the activation of stress response by (p)ppGpp could occur in an RpoS-independent manner and (p)ppGpp enables bacteria to integrate the control of growth and stress response in a seesaw fashion, thus acting as an important global regulator of the bacterial fitness landscape.
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Affiliation(s)
- Manlu Zhu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
| | - Haoyan Mu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
| | - Xiongfeng Dai
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences & National Key Laboratory of Green Pesticides, Central China Normal University, Wuhan, China
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29
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Cronan GE, Kuzminov A. Degron-Controlled Protein Degradation in Escherichia coli: New Approaches and Parameters. ACS Synth Biol 2024; 13:669-682. [PMID: 38317378 DOI: 10.1021/acssynbio.3c00768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Protein degron tags have proven to be uniquely useful for the characterization of gene function. Degrons can mediate quick depletion, usually within minutes, of a protein of interest, allowing researchers to characterize cellular responses to the loss of function. To develop a general-purpose degron tool in Escherichia coli, we sought to build upon a previously characterized system of SspB-dependent inducible protein degradation. For this, we created a family of expression vectors containing a destabilized allele of SspB, capable of a rapid and nearly perfect "off-to-on" induction response. Using this system, we demonstrated excellent control over several DNA metabolism enzymes. However, other substrates did not respond to degron tagging in such an ideal manner, indicating the apparent limitations of SspB-dependent systems. Several degron-tagged proteins were degraded too slowly to be completely depleted during active growth, whereas others appeared to be completely refractory to degron-promoted degradation. Thus, only a minority of our, admittedly biased, selection of degron substrates proved to be amenable to efficient SspB-catalyzed degradation. We also uncovered an apparent stalling and/or disengagement of ClpXP from a degron-tagged allele of beta-galactosidase (beta-gal). While a degron-containing fusion peptide attached to the carboxy-terminus of beta-gal was degraded quantitatively, no reductions in beta-gal activity or concentration were detected, demonstrating an apparently novel mechanism of protease resistance. We conclude that substrate-dependent effects of the SspB system present a continued challenge to the widespread adoption of this degron system. For substrates that prove to be degradable, we provide a series of titratable SspB-expression vehicles.
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Affiliation(s)
- Glen E Cronan
- Department of Microbiology, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana─Champaign, Urbana, Illinois 61801, United States
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30
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Lehman KM, May KL, Marotta J, Grabowicz M. Genetic analysis reveals a robust and hierarchical recruitment of the LolA chaperone to the LolCDE lipoprotein transporter. mBio 2024; 15:e0303923. [PMID: 38193657 PMCID: PMC10865981 DOI: 10.1128/mbio.03039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 11/29/2023] [Indexed: 01/10/2024] Open
Abstract
The outer membrane (OM) is an essential organelle of Gram-negative bacteria. Lipoproteins are key to building the OM, performing essential functions in several OM assembly machines. Lipoproteins mature in the inner membrane (IM) and are then trafficked to the OM. In Escherichia coli, the LolCDE transporter is needed to extract lipoproteins from the IM to begin trafficking. Lipoproteins are then transferred from LolCDE to the periplasmic chaperone LolA which ferries them to the OM for insertion by LolB. LolA recruitment by LolC is an essential trafficking step. Structural and biochemical studies suggested that two regions (termed Hook and Pad) within a periplasmic loop of LolC worked in tandem to recruit LolA, leading to a bipartite model for recruitment. Here, we genetically examine the LolC periplasmic loop in vivo using E. coli. Our findings challenge the bipartite interaction model. We show that while the Hook is essential for lipoprotein trafficking in vivo, lipoproteins are still efficiently trafficked when the Pad residues are inactivated. We show with AlphaFold2 multimer modeling that Hook:LolA interactions are likely universal among diverse Gram-negative bacteria. Conversely, Pad:LolA interactions vary across phyla. Our in vivo data redefine LolC:LolA recruitment into a hierarchical interaction model. We propose that the Hook is the major player in LolA recruitment, while the Pad plays an ancillary role that is important for efficiency but is ultimately dispensable. Our findings expand the understanding of a fundamental step in essential lipoprotein trafficking and have implications for efforts to develop new antibacterials that target LolCDE.IMPORTANCEResistance to current antibiotics is increasingly common. New antibiotics that target essential processes are needed to expand clinical options. For Gram-negative bacteria, their cell surface-the outer membrane (OM)-is an essential organelle and antibiotic barrier that is an attractive target for new antibacterials. Lipoproteins are key to building the OM. The LolCDE transporter is needed to supply the OM with lipoproteins and has been a focus of recent antibiotic discovery. In vitro evidence recently proposed a two-part interaction of LolC with LolA lipoprotein chaperone (which traffics lipoproteins to the OM) via "Hook" and "Pad" regions. We show that this model does not reflect lipoprotein trafficking in vivo. Only the Hook is essential for lipoprotein trafficking and is remarkably robust to mutational changes. The Pad is non-essential for lipoprotein trafficking but plays an ancillary role, contributing to trafficking efficiency. These insights inform ongoing efforts to drug LolCDE.
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Affiliation(s)
- Kelly M. Lehman
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Kerrie L. May
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Julianna Marotta
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Marcin Grabowicz
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
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Joy J, Fusari E, Milán M. Aneuploidy-induced cellular behaviors: Insights from Drosophila. Dev Cell 2024; 59:295-307. [PMID: 38320484 DOI: 10.1016/j.devcel.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 08/09/2023] [Accepted: 12/15/2023] [Indexed: 02/08/2024]
Abstract
A balanced gene complement is crucial for proper cell function. Aneuploidy, the condition of having an imbalanced chromosome set, alters the stoichiometry of gene copy numbers and protein complexes and has dramatic consequences at the cellular and organismal levels. In humans, aneuploidy is associated with different pathological conditions including cancer, microcephaly, mental retardation, miscarriages, and aging. Over the last century, Drosophila has provided a valuable system for studying the consequences of systemic aneuploidies. More recently, it has contributed to the identification and molecular dissection of aneuploidy-induced cellular behaviors and their impact at the tissue and organismal levels. In this perspective, we review this active field of research, first by comparing knowledge from yeast, mouse, and human cells, then by highlighting the contributions of Drosophila. The aim of these discussions was to further our understanding of the functional interplay between aneuploidy, cell physiology, and tissue homeostasis in human development and disease.
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Affiliation(s)
- Jery Joy
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Elena Fusari
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain
| | - Marco Milán
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10-12, 08028 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys, 23, 08010 Barcelona, Spain.
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32
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Bonde NJ, Kozlov AG, Cox MM, Lohman TM, Keck JL. Molecular insights into the prototypical single-stranded DNA-binding protein from E. coli. Crit Rev Biochem Mol Biol 2024; 59:99-127. [PMID: 38770626 PMCID: PMC11209772 DOI: 10.1080/10409238.2024.2330372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/11/2024] [Indexed: 05/22/2024]
Abstract
The SSB protein of Escherichia coli functions to bind single-stranded DNA wherever it occurs during DNA metabolism. Depending upon conditions, SSB occurs in several different binding modes. In the course of its function, SSB diffuses on ssDNA and transfers rapidly between different segments of ssDNA. SSB interacts with many other proteins involved in DNA metabolism, with 22 such SSB-interacting proteins, or SIPs, defined to date. These interactions chiefly involve the disordered and conserved C-terminal residues of SSB. When not bound to ssDNA, SSB can aggregate to form a phase-separated biomolecular condensate. Current understanding of the properties of SSB and the functional significance of its many intermolecular interactions are summarized in this review.
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Affiliation(s)
- Nina J. Bonde
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alexander G. Kozlov
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Michael M. Cox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Timothy M. Lohman
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - James L. Keck
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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33
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Gopinath A, Rath T, Morgner N, Joseph B. Lateral gating mechanism and plasticity of the β-barrel assembly machinery complex in micelles and Escherichia coli. PNAS NEXUS 2024; 3:pgae019. [PMID: 38312222 PMCID: PMC10833450 DOI: 10.1093/pnasnexus/pgae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/08/2024] [Indexed: 02/06/2024]
Abstract
The β-barrel assembly machinery (BAM) mediates the folding and insertion of the majority of outer membrane proteins (OMPs) in gram-negative bacteria. BAM is a penta-heterooligomeric complex consisting of the central β-barrel BamA and four interacting lipoproteins BamB, C, D, and E. The conformational switching of BamA between inward-open (IO) and lateral-open (LO) conformations is required for substrate recognition and folding. However, the mechanism for the lateral gating or how the structural details observed in vitro correspond with the cellular environment remains elusive. In this study, we addressed these questions by characterizing the conformational heterogeneity of BamAB, BamACDE, and BamABCDE complexes in detergent micelles and/or Escherichia coli using pulsed dipolar electron spin resonance spectroscopy (PDS). We show that the binding of BamB does not induce any visible changes in BamA, and the BamAB complex exists in the IO conformation. The BamCDE complex induces an IO to LO transition through a coordinated movement along the BamA barrel. However, the extracellular loop 6 (L6) is unaffected by the presence of lipoproteins and exhibits large segmental dynamics extending to the exit pore. PDS experiments with the BamABCDE complex in intact E. coli confirmed the dynamic behavior of both the lateral gate and the L6 in the native environment. Our results demonstrate that the BamCDE complex plays a key role in the function by regulating lateral gating in BamA.
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Affiliation(s)
- Aathira Gopinath
- Department of Physics, Freie Universität Berlin, Berlin, 14195, Germany
- Institute of Biophysics, Goethe Universität Frankfurt, Frankfurt, 60438, Germany
| | - Tobias Rath
- Institute of Physical and Theoretical Chemistry, Goethe Universität Frankfurt, Frankfurt, 60438, Germany
| | - Nina Morgner
- Institute of Physical and Theoretical Chemistry, Goethe Universität Frankfurt, Frankfurt, 60438, Germany
| | - Benesh Joseph
- Department of Physics, Freie Universität Berlin, Berlin, 14195, Germany
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34
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Kannaiah S, Goldberger O, Alam N, Barnabas G, Pozniak Y, Nussbaum-Shochat A, Schueler-Furman O, Geiger T, Amster-Choder O. MinD-RNase E interplay controls localization of polar mRNAs in E. coli. EMBO J 2024; 43:637-662. [PMID: 38243117 PMCID: PMC10897333 DOI: 10.1038/s44318-023-00026-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 01/21/2024] Open
Abstract
The E. coli transcriptome at the cell's poles (polar transcriptome) is unique compared to the membrane and cytosol. Several factors have been suggested to mediate mRNA localization to the membrane, but the mechanism underlying polar localization of mRNAs remains unknown. Here, we combined a candidate system approach with proteomics to identify factors that mediate mRNAs localization to the cell poles. We identified the pole-to-pole oscillating protein MinD as an essential factor regulating polar mRNA localization, although it is not able to bind RNA directly. We demonstrate that RNase E, previously shown to interact with MinD, is required for proper localization of polar mRNAs. Using in silico modeling followed by experimental validation, the membrane-binding site in RNase E was found to mediate binding to MinD. Intriguingly, not only does MinD affect RNase E interaction with the membrane, but it also affects its mode of action and dynamics. Polar accumulation of RNase E in ΔminCDE cells resulted in destabilization and depletion of mRNAs from poles. Finally, we show that mislocalization of polar mRNAs may prevent polar localization of their protein products. Taken together, our findings show that the interplay between MinD and RNase E determines the composition of the polar transcriptome, thus assigning previously unknown roles for both proteins.
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Affiliation(s)
- Shanmugapriya Kannaiah
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel.
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO, 63110, USA.
| | - Omer Goldberger
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Nawsad Alam
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Georgina Barnabas
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
- Department of Pathology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Yair Pozniak
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
| | - Anat Nussbaum-Shochat
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel
| | - Tamar Geiger
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, 6997801, Tel-Aviv, Israel
- Department of Molecular Cell Biology, Weizmann Institute of Science, 76100001, Rehovot, Israel
| | - Orna Amster-Choder
- Department of Microbiology and Molecular Genetics, IMRIC, The Hebrew University Faculty of Medicine, P.O.Box 12272, 91120, Jerusalem, Israel.
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35
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Amiri M, Kiniry SJ, Possemato AP, Mahmood N, Basiri T, Dufour CR, Tabatabaei N, Deng Q, Bellucci MA, Harwalkar K, Stokes MP, Giguère V, Kaufman RJ, Yamanaka Y, Baranov PV, Tahmasebi S, Sonenberg N. Impact of eIF2α phosphorylation on the translational landscape of mouse embryonic stem cells. Cell Rep 2024; 43:113615. [PMID: 38159280 PMCID: PMC10962698 DOI: 10.1016/j.celrep.2023.113615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/24/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024] Open
Abstract
The integrated stress response (ISR) is critical for cell survival under stress. In response to diverse environmental cues, eIF2α becomes phosphorylated, engendering a dramatic change in mRNA translation. The activation of ISR plays a pivotal role in the early embryogenesis, but the eIF2-dependent translational landscape in pluripotent embryonic stem cells (ESCs) is largely unexplored. We employ a multi-omics approach consisting of ribosome profiling, proteomics, and metabolomics in wild-type (eIF2α+/+) and phosphorylation-deficient mutant eIF2α (eIF2αA/A) mouse ESCs (mESCs) to investigate phosphorylated (p)-eIF2α-dependent translational control of naive pluripotency. We show a transient increase in p-eIF2α in the naive epiblast layer of E4.5 embryos. Absence of eIF2α phosphorylation engenders an exit from naive pluripotency following 2i (two chemical inhibitors of MEK1/2 and GSK3α/β) withdrawal. p-eIF2α controls translation of mRNAs encoding proteins that govern pluripotency, chromatin organization, and glutathione synthesis. Thus, p-eIF2α acts as a key regulator of the naive pluripotency gene regulatory network.
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Affiliation(s)
- Mehdi Amiri
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Stephen J Kiniry
- School of Biochemistry and Cell Biology, University College Cork, T12 XF62 Cork, Ireland
| | | | - Niaz Mahmood
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Tayebeh Basiri
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Catherine R Dufour
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Negar Tabatabaei
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Qiyun Deng
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Michael A Bellucci
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Keerthana Harwalkar
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada
| | - Matthew P Stokes
- Cell Signaling Technology, Inc., 3 Trask Lane, Danvers, MA 01923, USA
| | - Vincent Giguère
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada
| | - Randal J Kaufman
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Yojiro Yamanaka
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada; Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, T12 XF62 Cork, Ireland
| | - Soroush Tahmasebi
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL 60612, USA.
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC H3A 1A3, Canada.
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36
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Wollman AJM, Syeda AH, Howard JAL, Payne-Dwyer A, Leech A, Warecka D, Guy C, McGlynn P, Hawkins M, Leake MC. Tetrameric UvrD Helicase Is Located at the E. Coli Replisome due to Frequent Replication Blocks. J Mol Biol 2024; 436:168369. [PMID: 37977299 DOI: 10.1016/j.jmb.2023.168369] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/10/2023] [Accepted: 11/11/2023] [Indexed: 11/19/2023]
Abstract
DNA replication in all organisms must overcome nucleoprotein blocks to complete genome duplication. Accessory replicative helicases in Escherichia coli, Rep and UvrD, help remove these blocks and aid the re-initiation of replication. Mechanistic details of Rep function have emerged from recent live cell studies; however, the division of UvrD functions between its activities in DNA repair and role as an accessory helicase remain unclear in live cells. By integrating super-resolved single-molecule fluorescence microscopy with biochemical analysis, we find that UvrD self-associates into tetrameric assemblies and, unlike Rep, is not recruited to a specific replisome protein despite being found at approximately 80% of replication forks. Instead, its colocation with forks is likely due to the very high frequency of replication blocks composed of DNA-bound proteins, including RNA polymerase and factors involved in repairing DNA damage. Deleting rep and DNA repair factor genes mutS and uvrA, and inhibiting transcription through RNA polymerase mutation and antibiotic inhibition, indicates that the level of UvrD at the fork is dependent on UvrD's function. Our findings show that UvrD is recruited to sites of nucleoprotein blocks via different mechanisms to Rep and plays a multi-faceted role in ensuring successful DNA replication.
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Affiliation(s)
- Adam J M Wollman
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom; Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Aisha H Syeda
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom; Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Jamieson A L Howard
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom; Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Alex Payne-Dwyer
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom; Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Andrew Leech
- Bioscience Technology Facility, Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Dominika Warecka
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Colin Guy
- Covance Laboratories Ltd., Otley Road, Harrogate HG3 1PY, United Kingdom
| | - Peter McGlynn
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Michelle Hawkins
- Department of Biology, University of York, York YO10 5DD, United Kingdom
| | - Mark C Leake
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, United Kingdom; Department of Biology, University of York, York YO10 5DD, United Kingdom.
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37
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Mukherjee A, Chang YF, Huang Y, Benites NC, Ammar L, Ealy J, Polk M, Basan M. Plasticity of growth laws tunes resource allocation strategies in bacteria. PLoS Comput Biol 2024; 20:e1011735. [PMID: 38190385 PMCID: PMC10798636 DOI: 10.1371/journal.pcbi.1011735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 01/19/2024] [Accepted: 12/04/2023] [Indexed: 01/10/2024] Open
Abstract
Bacteria like E. coli grow at vastly different rates on different substrates, however, the precise reason for this variability is poorly understood. Different growth rates have been attributed to 'nutrient quality', a key parameter in bacterial growth laws. However, it remains unclear to what extent nutrient quality is rooted in fundamental biochemical constraints like the energy content of nutrients, the protein cost required for their uptake and catabolism, or the capacity of the plasma membrane for nutrient transporters. Here, we show that while nutrient quality is indeed reflected in protein investment in substrate-specific transporters and enzymes, this is not a fundamental limitation on growth rate, at least for certain 'poor' substrates. We show that it is possible to turn mannose, one of the 'poorest' substrates of E. coli, into one of the 'best' substrates by reengineering chromosomal promoters of the mannose transporter and metabolic enzymes required for mannose degradation. This result falls in line with previous observations of more subtle growth rate improvement for many other carbon sources. However, we show that this faster growth rate comes at the cost of diverse cellular capabilities, reflected in longer lag phases, worse starvation survival and lower motility. We show that addition of cAMP to the medium can rescue these phenotypes but imposes a corresponding growth cost. Based on these data, we propose that nutrient quality is largely a self-determined, plastic property that can be modulated by the fraction of proteomic resources devoted to a specific substrate in the much larger proteome sector of catabolically activated genes. Rather than a fundamental biochemical limitation, nutrient quality reflects resource allocation decisions that are shaped by evolution in specific ecological niches and can be quickly adapted if necessary.
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Affiliation(s)
- Avik Mukherjee
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yu-Fang Chang
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yanqing Huang
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nina Catherine Benites
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Leander Ammar
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jade Ealy
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mark Polk
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Markus Basan
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
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Schumacher K, Gelhausen R, Kion-Crosby W, Barquist L, Backofen R, Jung K. Ribosome profiling reveals the fine-tuned response of Escherichia coli to mild and severe acid stress. mSystems 2023; 8:e0103723. [PMID: 37909716 PMCID: PMC10746267 DOI: 10.1128/msystems.01037-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Bacteria react very differently to survive in acidic environments, such as the human gastrointestinal tract. Escherichia coli is one of the extremely acid-resistant bacteria and has a variety of acid-defense mechanisms. Here, we provide the first genome-wide overview of the adaptations of E. coli K-12 to mild and severe acid stress at both the transcriptional and translational levels. Using ribosome profiling and RNA sequencing, we uncover novel adaptations to different degrees of acidity, including previously hidden stress-induced small proteins and novel key transcription factors for acid defense, and report mRNAs with pH-dependent differential translation efficiency. In addition, we distinguish between acid-specific adaptations and general stress response mechanisms using denoising autoencoders. This workflow represents a powerful approach that takes advantage of next-generation sequencing techniques and machine learning to systematically analyze bacterial stress responses.
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Affiliation(s)
- Kilian Schumacher
- Faculty of Biology, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Rick Gelhausen
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Willow Kion-Crosby
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
- University of Würzburg, Faculty of Medicine, Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
- University of Würzburg, Faculty of Medicine, Würzburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Kirsten Jung
- Faculty of Biology, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
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39
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Rosenberg SM. Life, the genome and everything. J Bacteriol 2023; 205:e0027223. [PMID: 38018999 PMCID: PMC10742612 DOI: 10.1128/jb.00272-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023] Open
Abstract
In this issue of the Journal of Bacteriology, N. J. Bonde, E. A. Wood, K. S. Myers, M. Place, J. L. Keck, and M. M. Cox (J Bacteriol 205:e00184-23, 2023, https//doi.org/10.1128/jb.00184-23) used an unbiased transposon-sequencing (Tn-seq) screen to identify proteins required for life when cells lose the RecG branched-DNA helicase (synthetic lethality). The proteins' identities indicate pathways that prevent endogenous DNA damage, pathways that prevent its homology-directed repair (HDR) "strand-exchange" intermediates between sister chromosomes, and pathways that resolve those intermediates. All avoid intermediate pile-up, which blocks chromosome segregation, causing "death-by-recombination." DNA damage is managed to regulate crucial but potentially lethal HDR.
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Affiliation(s)
- Susan M. Rosenberg
- Departments of Molecular & Human Genetics, Biochemistry & Molecular Biology, Molecular Virology and Microbiology, and the Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas, USA
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40
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Re A. Translational efficiency in gas-fermenting bacteria: Adding a new layer of regulation to gene expression in acetogens. iScience 2023; 26:108383. [PMID: 38034355 PMCID: PMC10684804 DOI: 10.1016/j.isci.2023.108383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
Major advances in mastering metabolism of single carbon (C1) gaseous feedstocks in acetogenic microorganisms are primed to fuel the transition toward environmentally sustainable and cost-efficient production schemes of biofuels and value-added biochemicals. Since acetogens grow under autotrophic energy-limited conditions, protein synthesis is expected to be controlled. This survey integrated publicly available RNA sequencing and ribosome profiling studies of several acetogens, providing data on genome-scale transcriptional and translational responses of A. woodii, E. limosum, C. drakei, and C. ljungdahlii to autotrophic and heterotrophic growth conditions. The extent of translational efficiency turned out to vary across key functional modules in acetogens' metabolism. Translational control was confirmed to support stoichiometric protein production in multimeric complexes. Comparing the autotrophic to the heterotrophic growth condition revealed growth-dependent regulation of translational efficiency, pointing at translational buffering as a widespread phenomenon shared by acetogens.
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Affiliation(s)
- Angela Re
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
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41
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Irshad IU, Sharma AK. Decoding stoichiometric protein synthesis in E. coli through translation rate parameters. BIOPHYSICAL REPORTS 2023; 3:100131. [PMID: 37789867 PMCID: PMC10542608 DOI: 10.1016/j.bpr.2023.100131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/11/2023] [Indexed: 10/05/2023]
Abstract
E. coli is one of the most widely used organisms for understanding the principles of cellular and molecular genetics. However, we are yet to understand the origin of several experimental observations related to the regulation of gene expression in E. coli. One of the prominent examples in this context is the proportional synthesis in multiprotein complexes where all of their obligate subunits are produced in proportion to their stoichiometry. In this work, by combining the next-generation sequencing data with the stochastic simulations of protein synthesis, we explain the origin of proportional protein synthesis in multicomponent complexes. We find that the estimated initiation rates for the translation of all subunits in those complexes are proportional to their stoichiometry. This constraint on protein synthesis kinetics enforces proportional protein synthesis without requiring any feedback mechanism. We also find that the translation initiation rates in E. coli are influenced by the coding sequence length and the enrichment of A and C nucleotides near the start codon. Thus, this study rationalizes the role of conserved and nonrandom features of genes in regulating the translation kinetics and unravels a key principle of the regulation of protein synthesis.
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Affiliation(s)
| | - Ajeet K. Sharma
- Department of Physics, Indian Institute of Technology Jammu, Jammu, India
- Department of Biosciences and Bioengineering, Indian Institute of Technology Jammu, Jammu, India
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42
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Nakano Y, Gamper H, McGuigan H, Maharjan S, Sun Z, Krishnan K, Yigit E, Li NS, Piccirilli JA, Kleiner R, Nichols N, Hou YM. Genome-Wide Profiling of tRNA Using an Unexplored Reverse Transcriptase with High Processivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.09.569604. [PMID: 38106225 PMCID: PMC10723452 DOI: 10.1101/2023.12.09.569604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Monitoring the dynamic changes of cellular tRNA pools is challenging, due to the extensive post-transcriptional modifications of individual species. The most critical component in tRNAseq is a processive reverse transcriptase (RT) that can read through each modification with high efficiency. Here we show that the recently developed group-II intron RT Induro has the processivity and efficiency necessary to profile tRNA dynamics. Using our Induro-tRNAseq, simpler and more comprehensive than the best methods to date, we show that Induro progressively increases readthrough of tRNA over time and that the mechanism of increase is selective removal of RT stops, without altering the misincorporation frequency. We provide a parallel dataset of the misincorporation profile of Induro relative to the related TGIRT RT to facilitate the prediction of non-annotated modifications. We report an unexpected modification profile among human proline isoacceptors, absent from mouse and lower eukaryotes, that indicates new biology of decoding proline codons.
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43
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Bryant OJ, Lastovka F, Powell J, Chung BYW. The distinct translational landscapes of gram-negative Salmonella and gram-positive Listeria. Nat Commun 2023; 14:8167. [PMID: 38071303 PMCID: PMC10710512 DOI: 10.1038/s41467-023-43759-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
Translational control in pathogenic bacteria is fundamental to gene expression and affects virulence and other infection phenotypes. We used an enhanced ribosome profiling protocol coupled with parallel transcriptomics to capture accurately the global translatome of two evolutionarily distant pathogenic bacteria-the Gram-negative bacterium Salmonella and the Gram-positive bacterium Listeria. We find that the two bacteria use different mechanisms to translationally regulate protein synthesis. In Salmonella, in addition to the expected correlation between translational efficiency and cis-regulatory features such as Shine-Dalgarno (SD) strength and RNA secondary structure around the initiation codon, our data reveal an effect of the 2nd and 3rd codons, where the presence of tandem lysine codons (AAA-AAA) enhances translation in both Salmonella and E. coli. Strikingly, none of these features are seen in efficiently translated Listeria transcripts. Instead, approximately 20% of efficiently translated Listeria genes exhibit 70 S footprints seven nt upstream of the authentic start codon, suggesting that these genes may be subject to a novel translational initiation mechanism. Our results show that SD strength is not a direct hallmark of translational efficiency in all bacteria. Instead, Listeria has evolved additional mechanisms to control gene expression level that are distinct from those utilised by Salmonella and E. coli.
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Affiliation(s)
- Owain J Bryant
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
- Centre for Structural Biology, National Cancer Institute, 21702, Frederick, MD, USA
| | - Filip Lastovka
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Jessica Powell
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Betty Y-W Chung
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
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44
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Olavarria K, Becker MV, Sousa DZ, van Loosdrecht MC, Wahl SA. Design and thermodynamic analysis of a pathway enabling anaerobic production of poly-3-hydroxybutyrate in Escherichia coli. Synth Syst Biotechnol 2023; 8:629-639. [PMID: 37823039 PMCID: PMC10562921 DOI: 10.1016/j.synbio.2023.09.005] [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: 06/24/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages, such as increased yields and reduced energy dissipation. However, lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium. While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering, the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented. In this study, we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate (PHB) in the model organism Escherichia coli. Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation. We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway. According to our calculations, the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoA β-ketothiolase (EC 2.3.1.9) and the acetoacetyl-CoA reductase (EC 1.1.1.36). Furthermore, we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes. In the case of the engineered conversion route, the protein pool necessary to sustain the desired fluxes could account for 20% of the whole cell dry weight.
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Affiliation(s)
- Karel Olavarria
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Marco V. Becker
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Diana Z. Sousa
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Mark C.M. van Loosdrecht
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - S. Aljoscha Wahl
- Lehrstuhl für Bioverfahrenstechnik, Friedrich-Alexander-Universität, Paul-Gordan-Strasse 3, 91052, Erlangen, Germany
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45
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Wang S, Huang T, Xie Z, Wan L, Ren H, Wu T, Xie L, Luo S, Li M, Xie Z, Fan Q, Huang J, Zeng T, Zhang Y, Zhang M, Wei Y. Transcriptomic and Translatomic Analyses Reveal Insights into the Signaling Pathways of the Innate Immune Response in the Spleens of SPF Chickens Infected with Avian Reovirus. Viruses 2023; 15:2346. [PMID: 38140587 PMCID: PMC10747248 DOI: 10.3390/v15122346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Avian reovirus (ARV) infection is prevalent in farmed poultry and causes viral arthritis and severe immunosuppression. The spleen plays a very important part in protecting hosts against infectious pathogens. In this research, transcriptome and translatome sequencing technology were combined to investigate the mechanisms of transcriptional and translational regulation in the spleen after ARV infection. On a genome-wide scale, ARV infection can significantly reduce the translation efficiency (TE) of splenic genes. Differentially expressed translational efficiency genes (DTEGs) were identified, including 15 upregulated DTEGs and 396 downregulated DTEGs. These DTEGs were mainly enriched in immune regulation signaling pathways, which indicates that ARV infection reduces the innate immune response in the spleen. In addition, combined analyses revealed that the innate immune response involves the effects of transcriptional and translational regulation. Moreover, we discovered the key gene IL4I1, the most significantly upregulated gene at both the transcriptional and translational levels. Further studies in DF1 cells showed that overexpression of IL4I1 could inhibit the replication of ARV, while inhibiting the expression of endogenous IL4I1 with siRNA promoted the replication of ARV. Overexpression of IL4I1 significantly downregulated the mRNA expression of IFN-β, LGP2, TBK1 and NF-κB; however, the expression of these genes was significantly upregulated after inhibition of IL4I1, suggesting that IL4I1 may be a negative feedback effect of innate immune signaling pathways. In addition, there may be an interaction between IL4I1 and ARV σA protein, and we speculate that the IL4I1 protein plays a regulatory role by interacting with the σA protein. This study not only provides a new perspective on the regulatory mechanisms of the innate immune response after ARV infection but also enriches the knowledge of the host defense mechanisms against ARV invasion and the outcome of ARV evasion of the host's innate immune response.
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Affiliation(s)
- Sheng Wang
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Tengda Huang
- Division of Liver Surgery, Department of General Surgery, Laboratory of Liver Surgery, and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China;
| | - Zhixun Xie
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Lijun Wan
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Hongyu Ren
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Tian Wu
- NHC Key Laboratory of Transplant Engineering and Immunology, Regenerative Medicine Research Center, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital of Sichuan University, Chengdu 610041, China;
| | - Liji Xie
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Sisi Luo
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Meng Li
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Zhiqin Xie
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Qing Fan
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Jiaoling Huang
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Tingting Zeng
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Yanfang Zhang
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - Minxiu Zhang
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
| | - You Wei
- Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning 530000, China; (S.W.); (L.W.); (H.R.); (L.X.); (S.L.); (M.L.); (Z.X.); (Q.F.); (J.H.); (T.Z.); (Y.Z.); (M.Z.); (Y.W.)
- Key Laboratory of China (Guangxi)-ASEAN Cross-Border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs of China, Nanning 530000, China
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Cronan GE, Kuzminov A. Degron-controlled protein degradation in Escherichia coli: New Approaches and Parameters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566101. [PMID: 37986802 PMCID: PMC10659297 DOI: 10.1101/2023.11.08.566101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Protein degron tags have proven uniquely useful for characterization of gene function. Degrons mediate quick depletion, usually within minutes, of a protein of interest - allowing researchers to characterize cellular responses to the loss of function. To develop a general purpose degron tool in E. coli, we sought to build upon a previously characterized system of SspB-dependent inducible protein degradation. For this, we created a family of expression vectors containing a destabilized allele of SspB, capable of a rapid and nearly perfect "off-to-on" induction response. Using this system, we demonstrated control over several enzymes of DNA metabolism, but also found with other substates apparent limitations of a SspB-dependent system. Several degron target proteins were degraded too slowly to affect their complete depletion during active growth, whereas others appeared completely refractory to degron-promoted degradation. We demonstrated that a model substrate, beta-galactosidase, was positively recognized as a degron substrate, but failed to be degraded by the ClpXP protease - demonstrating an apparently unknown mechanism of protease resistance. Thus, only a minority of our, admittedly biased, selection of degron substates proved amenable to rapid SspB-catalyzed degradation. We conclude that substrate-dependence of the SspB system remains a critical factor for the success of this degron system. For substrates that prove degradable, we provide a series of titratable SspB-expression vehicles.
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Affiliation(s)
- Glen E. Cronan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Pourciau C, Yakhnin H, Pannuri A, Gorelik MG, Lai YJ, Romeo T, Babitzke P. CsrA coordinates the expression of ribosome hibernation and anti-σ factor proteins. mBio 2023; 14:e0258523. [PMID: 37943032 PMCID: PMC10746276 DOI: 10.1128/mbio.02585-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 10/02/2023] [Indexed: 11/10/2023] Open
Abstract
Bacterial growth rate varies due to changing physiological signals and is fundamentally dependent on protein synthesis. Consequently, cells alter their transcription and translation machinery to optimize the capacity for protein production under varying conditions and growth rates. Our findings demonstrate that the post-transcriptional regulator CsrA in Escherichia coli controls the expression of genes that participate in these processes. During exponential growth, CsrA represses the expression of proteins that alter or inhibit RNA polymerase (RNAP) and ribosome activity, including the ribosome hibernation factors RMF, RaiA, YqjD, ElaB, YgaM, and SRA, as well as the anti-σ70 factor, Rsd. Upon entry into the stationary phase, RaiA, YqjD, ElaB, and SRA expression was derepressed and that of RMF, YgaM, and Rsd was activated in the presence of CsrA. This pattern of gene expression likely supports global protein expression during active growth and helps limit protein production to a basal level when nutrients are limited. In addition, we identified genes encoding the paralogous C-tail anchored inner membrane proteins YqjD and ElaB as robust, direct targets of CsrA-mediated translational repression. These proteins bind ribosomes and mediate their localization to the inner cell membrane, impacting a variety of processes including protein expression and membrane integrity. Previous studies found that YqjD overexpression inhibits cell growth, suggesting that appropriate regulation of YqjD expression might play a key role in cell viability. CsrA-mediated regulation of yqjD and ribosome hibernation factors reveals a new role for CsrA in appropriating cellular resources for optimum growth under varying conditions.IMPORTANCEThe Csr/Rsm system (carbon storage regulator or repressor of stationary phase metabolites) is a global post-transcriptional regulatory system that coordinates and responds to environmental cues and signals, facilitating the transition between active growth and stationary phase. Another key determinant of bacterial lifestyle decisions is the management of the cellular gene expression machinery. Here, we investigate the connection between these two processes in Escherichia coli. Disrupted regulation of the transcription and translation machinery impacts many cellular functions, including gene expression, growth, fitness, and stress resistance. Elucidating the role of the Csr system in controlling the activity of RNAP and ribosomes advances our understanding of mechanisms controlling bacterial growth. A more complete understanding of these processes could lead to the improvement of therapeutic strategies for recalcitrant infections.
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Affiliation(s)
- Christine Pourciau
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Archanna Pannuri
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Mark G. Gorelik
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ying-Jung Lai
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Tony Romeo
- Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
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Lehman KM, May KL, Marotta J, Grabowicz M. Genetic analysis reveals a robust and hierarchical recruitment of the LolA chaperone to the LolCDE lipoprotein transporter. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566237. [PMID: 37986794 PMCID: PMC10659402 DOI: 10.1101/2023.11.08.566237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The outer membrane (OM) is an essential organelle of Gram-negative bacteria. Lipoproteins are key to building the OM, performing essential functions in several OM assembly machines. Lipoproteins mature in the inner membrane (IM) and are then trafficked to the OM. In Escherichia coli, the LolCDE transporter is needed to extract lipoproteins from the IM to begin trafficking. Lipoproteins are then transferred from LolCDE to the periplasmic chaperone LolA which ferries them to the OM for insertion by LolB. LolA recruitment by LolC is an essential trafficking step. Structural and biochemical studies suggested that two regions (termed Hook and Pad) within a periplasmic loop of LolC worked in tandem to recruit LolA, leading to a bipartite model for recruitment. Here, we genetically examine the LolC periplasmic loop in vivo using E. coli. Our findings challenge the bipartite interaction model. We show that while the Hook is essential for lipoprotein trafficking in vivo, lipoproteins are still efficiently trafficked when the Pad residues are inactivated. We show with AlphaFold2 multimer modeling that Hook:LolA interactions are likely universal among diverse Gram-negative bacteria. Conversely, Pad:LolA interactions vary across phyla. Our in vivo data redefine LolC:LolA recruitment into a hierarchical interaction model. We propose that the Hook is the major player in LolA recruitment, while the Pad plays an ancillary role that is important for efficiency but is ultimately dispensable. Our findings expand the understanding of a fundamental step in essential lipoprotein trafficking and have implications for efforts to develop new antibacterials that target LolCDE.
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Affiliation(s)
- Kelly M. Lehman
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Kelly M. Lehman and Kerrie L. May contributed equally to this work. Author order was determined alphabetically
| | - Kerrie L. May
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Kelly M. Lehman and Kerrie L. May contributed equally to this work. Author order was determined alphabetically
| | - Julianna Marotta
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Marcin Grabowicz
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
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Penzo A, Palancade B. Puzzling out nuclear pore complex assembly. FEBS Lett 2023; 597:2705-2727. [PMID: 37548888 DOI: 10.1002/1873-3468.14713] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/12/2023] [Accepted: 07/17/2023] [Indexed: 08/08/2023]
Abstract
Nuclear pore complexes (NPCs) are sophisticated multiprotein assemblies embedded within the nuclear envelope and controlling the exchanges of molecules between the cytoplasm and the nucleus. In this review, we summarize the mechanisms by which these elaborate complexes are built from their subunits, the nucleoporins, based on our ever-growing knowledge of NPC structural organization and on the recent identification of additional features of this process. We present the constraints faced during the production of nucleoporins, their gathering into oligomeric complexes, and the formation of NPCs within nuclear envelopes, and review the cellular strategies at play, from co-translational assembly to the enrolment of a panel of cofactors. Remarkably, the study of NPCs can inform our perception of the biogenesis of multiprotein complexes in general - and vice versa.
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Affiliation(s)
- Arianna Penzo
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Benoit Palancade
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
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Liu D, Lv H, Wang Y, Chen J, Li D, Huang R. Selective RNA Processing and Stabilization are Multi-Layer and Stoichiometric Regulators of Gene Expression in Escherichia coli. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301459. [PMID: 37845007 PMCID: PMC10667835 DOI: 10.1002/advs.202301459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/29/2023] [Indexed: 10/18/2023]
Abstract
Selective RNA processing and stabilization (SRPS) facilitates the differential expression of multiple genes in polycistronic operons. However, how the coordinated actions of SRPS-related enzymes affect stoichiometric regulation remains unclear. In the present study, the first genome-wide targetome analysis is reported of these enzymes in Escherichia coli, at a single-nucleotide resolution. A strictly linear relationship is observed between the RNA pyrophosphohydrolase processing ratio and scores assigned to the first three nucleotides of the primary transcript. Stem-loops associated with PNPase targetomes exhibit a folding free energy that is negatively correlated with the termination ratio of PNPase at the 3' end. More than one-tenth of the RNase E processing sites in the 5'-untranslated regions(UTR) form different stem-loops that affect ribosome-binding and translation efficiency. The effectiveness of the SRPS elements is validated using a dual-fluorescence reporter system. The findings highlight a multi-layer and quantitative regulatory method for optimizing the stoichiometric expression of genes in bacteria and promoting the application of SRPS in synthetic biology.
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Affiliation(s)
- Daixi Liu
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
- School of Pharmaceutical Sciences, Shandong University, 44 Wenhuaxi Road, Jinan, Shandong, 250012, China
| | - Haibo Lv
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
| | - Yafei Wang
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
| | - Jinyu Chen
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
| | - Dexin Li
- School of Computer Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
| | - Ranran Huang
- Institute of Marine Science and Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong, 266237, China
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