1
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Iyer A, Frallicciardi J, le Paige UBA, Narasimhan S, Luo Y, Alvarez Sieiro P, Syga L, van den Brekel F, Minh Tran B, Tjioe R, Schuurman-Wolters G, C A Stuart M, Baldus M, van Ingen H, Poolman B. The structure and function of the bacterial osmotically inducible protein Y. J Mol Biol 2024:168668. [PMID: 38908784 DOI: 10.1016/j.jmb.2024.168668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/14/2024] [Accepted: 06/14/2024] [Indexed: 06/24/2024]
Abstract
The ability to adapt to osmotically diverse and fluctuating environments is critical to the survival and resilience of bacteria that colonize the human gut and urinary tract. Environmental stress often provides cross-protection against other challenges and increases antibiotic tolerance of bacteria. Thus, it is critical to understand how E. coli and other microbes survive and adapt to stress conditions. The osmotically inducible protein Y (OsmY) is significantly upregulated in response to hypertonicity. Yet its function remains unknown for decades. We determined the solution structure and dynamics of OsmY by nuclear magnetic resonance spectroscopy, which revealed that the two Bacterial OsmY and Nodulation (BON) domains of the protein are flexibly linked under low- and high-salinity conditions. In-cell solid-state NMR further indicates that there are no gross structural changes in OsmY as a function of osmotic stress. Using cryo-electron and super-resolution fluorescence microscopy, we show that OsmY attenuates plasmolysis-induced structural changes in E. coli and improves the time to growth resumption after osmotic upshift. Structure-guided mutational and functional studies demonstrate that exposed hydrophobic residues in the BON1 domain are critical for the function of OsmY. We find no evidence for membrane interaction of the BON domains of OsmY, contrary to current assumptions. Instead, at high ionic strength, we observe an interaction with the water channel, AqpZ. Thus, OsmY does not play a simple structural role in E. coli but may influence a cascade of osmoregulatory functions of the cell.
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Affiliation(s)
- Aditya Iyer
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Jacopo Frallicciardi
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ulric B A le Paige
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Siddarth Narasimhan
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Yanzhang Luo
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Patricia Alvarez Sieiro
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Lukasz Syga
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Floris van den Brekel
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Buu Minh Tran
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Rendy Tjioe
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gea Schuurman-Wolters
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Marc C A Stuart
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Hugo van Ingen
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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2
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Raczyłło E, Gołowicz D, Skóra T, Kazimierczuk K, Kondrat S. Size Sensitivity of Metabolite Diffusion in Macromolecular Crowds. NANO LETTERS 2024; 24. [PMID: 38607288 PMCID: PMC11057039 DOI: 10.1021/acs.nanolett.3c05100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 04/13/2024]
Abstract
Metabolites play crucial roles in cellular processes, yet their diffusion in the densely packed interiors of cells remains poorly understood, compounded by conflicting reports in existing studies. Here, we employ pulsed-gradient stimulated-echo NMR and Brownian/Stokesian dynamics simulations to elucidate the behavior of nano- and subnanometer-sized tracers in crowded environments. Using Ficoll as a crowder, we observe a linear decrease in tracer diffusivity with increasing occupied volume fraction, persisting─somewhat surprisingly─up to volume fractions of 30-40%. While simulations suggest a linear correlation between diffusivity slowdown and particle size, experimental findings hint at a more intricate relationship, possibly influenced by Ficoll's porosity. Simulations and numerical calculations of tracer diffusivity in the E. coli cytoplasm show a nonlinear yet monotonic diffusion slowdown with particle size. We discuss our results in the context of nanoviscosity and discrepancies with existing studies.
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Affiliation(s)
- Edyta Raczyłło
- Institute
of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
- Department
of Theoretical Chemistry, Institute of Chemical Sciences, Faculty
of Chemistry, Maria Curie-Skłodowska
University in Lublin, 20-031 Lublin, Poland
| | - Dariusz Gołowicz
- Institute
of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Tomasz Skóra
- Institute
of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
- Scientific
Computing and Imaging Institute, University
of Utah, Salt Lake City, Utah 84112, United States
| | | | - Svyatoslav Kondrat
- Institute
of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
- Institute
for Computational Physics, University of
Stuttgart 70569, Stuttgart, Germany
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3
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Monterroso B, Margolin W, Boersma AJ, Rivas G, Poolman B, Zorrilla S. Macromolecular Crowding, Phase Separation, and Homeostasis in the Orchestration of Bacterial Cellular Functions. Chem Rev 2024; 124:1899-1949. [PMID: 38331392 PMCID: PMC10906006 DOI: 10.1021/acs.chemrev.3c00622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/01/2023] [Accepted: 01/10/2024] [Indexed: 02/10/2024]
Abstract
Macromolecular crowding affects the activity of proteins and functional macromolecular complexes in all cells, including bacteria. Crowding, together with physicochemical parameters such as pH, ionic strength, and the energy status, influences the structure of the cytoplasm and thereby indirectly macromolecular function. Notably, crowding also promotes the formation of biomolecular condensates by phase separation, initially identified in eukaryotic cells but more recently discovered to play key functions in bacteria. Bacterial cells require a variety of mechanisms to maintain physicochemical homeostasis, in particular in environments with fluctuating conditions, and the formation of biomolecular condensates is emerging as one such mechanism. In this work, we connect physicochemical homeostasis and macromolecular crowding with the formation and function of biomolecular condensates in the bacterial cell and compare the supramolecular structures found in bacteria with those of eukaryotic cells. We focus on the effects of crowding and phase separation on the control of bacterial chromosome replication, segregation, and cell division, and we discuss the contribution of biomolecular condensates to bacterial cell fitness and adaptation to environmental stress.
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Affiliation(s)
- Begoña Monterroso
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
| | - William Margolin
- Department
of Microbiology and Molecular Genetics, McGovern Medical School, UTHealth-Houston, Houston, Texas 77030, United States
| | - Arnold J. Boersma
- Cellular
Protein Chemistry, Bijvoet Centre for Biomolecular Research, Faculty
of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Germán Rivas
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
| | - Bert Poolman
- Department
of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Silvia Zorrilla
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
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4
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Yu S, Chu R, Wu G, Meng X. A Novel Fractional Brownian Dynamics Method for Simulating the Dynamics of Confined Bottle-Brush Polymers in Viscoelastic Solution. Polymers (Basel) 2024; 16:524. [PMID: 38399901 PMCID: PMC10891538 DOI: 10.3390/polym16040524] [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: 01/03/2024] [Revised: 02/11/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
In crowded fluids, polymer segments can exhibit anomalous subdiffusion due to the viscoelasticity of the surrounding environment. Previous single-particle tracking experiments revealed that such anomalous diffusion in complex fluids (e.g., in bacterial cytoplasm) can be described by fractional Brownian motion (fBm). To investigate how the viscoelastic media affects the diffusive behaviors of polymer segments without resolving single crowders, we developed a novel fractional Brownian dynamics method to simulate the dynamics of polymers under confinement. In this work, instead of using Gaussian random numbers ("white Gaussian noise") to model the Brownian force as in the standard Brownian dynamics simulations, we introduce fractional Gaussian noise (fGn) in our homemade fractional Brownian dynamics simulation code to investigate the anomalous diffusion of polymer segments by using a simple "bottle-brush"-type polymer model. The experimental results of the velocity autocorrelation function and the exponent that characterizes the subdiffusion of the confined polymer segments can be reproduced by this simple polymer model in combination with fractional Gaussian noise (fGn), which mimics the viscoelastic media.
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Affiliation(s)
- Shi Yu
- Department of Chemical Engineering, China University of Mining & Technology, Xuzhou 221116, China; (R.C.); (G.W.); (X.M.)
| | - Ruizhi Chu
- Department of Chemical Engineering, China University of Mining & Technology, Xuzhou 221116, China; (R.C.); (G.W.); (X.M.)
- Key Laboratory of Coal-Based CO2 Capture and Geological Storage, China University of Mining & Technology, Xuzhou 221116, China
| | - Guoguang Wu
- Department of Chemical Engineering, China University of Mining & Technology, Xuzhou 221116, China; (R.C.); (G.W.); (X.M.)
- Key Laboratory of Coal-Based CO2 Capture and Geological Storage, China University of Mining & Technology, Xuzhou 221116, China
| | - Xianliang Meng
- Department of Chemical Engineering, China University of Mining & Technology, Xuzhou 221116, China; (R.C.); (G.W.); (X.M.)
- Key Laboratory of Coal-Based CO2 Capture and Geological Storage, China University of Mining & Technology, Xuzhou 221116, China
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5
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Lee Upton S, Tay JW, Schwartz DK, Sousa MC. Similarly slow diffusion of BAM and SecYEG complexes in live E. coli cells observed with 3D spt-PALM. Biophys J 2023; 122:4382-4394. [PMID: 37853695 PMCID: PMC10698321 DOI: 10.1016/j.bpj.2023.10.017] [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: 04/19/2023] [Revised: 09/05/2023] [Accepted: 10/16/2023] [Indexed: 10/20/2023] Open
Abstract
The β-barrel assembly machinery (BAM) complex is responsible for inserting outer membrane proteins (OMPs) into the Escherichia coli outer membrane. The SecYEG translocon inserts inner membrane proteins into the inner membrane and translocates both soluble proteins and nascent OMPs into the periplasm. Recent reports describe Sec possibly playing a direct role in OMP biogenesis through interactions with the soluble polypeptide transport-associated (POTRA) domains of BamA (the central OMP component of BAM). Here we probe the diffusion behavior of these protein complexes using photoactivatable super-resolution localization microscopy and single-particle tracking in live E. coli cells of BAM and SecYEG components BamA and SecE and compare them to other outer and inner membrane proteins. To accurately measure trajectories on the highly curved cell surface, three-dimensional tracking was performed using double-helix point-spread function microscopy. All proteins tested exhibit two diffusive modes characterized by "slow" and "fast" diffusion coefficients. We implement a diffusion coefficient analysis as a function of the measurement lag time to separate positional uncertainty from true mobility. The resulting true diffusion coefficients of the slow and fast modes showed a complete immobility of full-length BamA constructs in the time frame of the experiment, whereas the OMP OmpLA displayed a slow diffusion consistent with the high viscosity of the outer membrane. The periplasmic POTRA domains of BamA were found to anchor BAM to other cellular structures and render it immobile. However, deletion of individual distal POTRA domains resulted in increased mobility, suggesting that these domains are required for the full set of cellular interactions. SecE diffusion was much slower than that of the inner membrane protein PgpB and was more like OMPs and BamA. Strikingly, SecE diffused faster upon POTRA domain deletion. These results are consistent with the existence of a BAM-SecYEG trans-periplasmic assembly in live E. coli cells.
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Affiliation(s)
- Stephen Lee Upton
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado
| | - Jian Wei Tay
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado
| | - Daniel Keith Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado
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6
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Prindle JR, de Cuba OIC, Gahlmann A. Single-molecule tracking to determine the abundances and stoichiometries of freely-diffusing protein complexes in living cells: Past applications and future prospects. J Chem Phys 2023; 159:071002. [PMID: 37589409 PMCID: PMC10908566 DOI: 10.1063/5.0155638] [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: 04/21/2023] [Accepted: 07/06/2023] [Indexed: 08/18/2023] Open
Abstract
Most biological processes in living cells rely on interactions between proteins. Live-cell compatible approaches that can quantify to what extent a given protein participates in homo- and hetero-oligomeric complexes of different size and subunit composition are therefore critical to advance our understanding of how cellular physiology is governed by these molecular interactions. Biomolecular complex formation changes the diffusion coefficient of constituent proteins, and these changes can be measured using fluorescence microscopy-based approaches, such as single-molecule tracking, fluorescence correlation spectroscopy, and fluorescence recovery after photobleaching. In this review, we focus on the use of single-molecule tracking to identify, resolve, and quantify the presence of freely-diffusing proteins and protein complexes in living cells. We compare and contrast different data analysis methods that are currently employed in the field and discuss experimental designs that can aid the interpretation of the obtained results. Comparisons of diffusion rates for different proteins and protein complexes in intracellular aqueous environments reported in the recent literature reveal a clear and systematic deviation from the Stokes-Einstein diffusion theory. While a complete and quantitative theoretical explanation of why such deviations manifest is missing, the available data suggest the possibility of weighing freely-diffusing proteins and protein complexes in living cells by measuring their diffusion coefficients. Mapping individual diffusive states to protein complexes of defined molecular weight, subunit stoichiometry, and structure promises to provide key new insights into how protein-protein interactions regulate protein conformational, translational, and rotational dynamics, and ultimately protein function.
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Affiliation(s)
- Joshua Robert Prindle
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA
| | - Olivia Isabella Christiane de Cuba
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
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7
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Bryant SJ, Machta BB. Physical Constraints in Intracellular Signaling: The Cost of Sending a Bit. PHYSICAL REVIEW LETTERS 2023; 131:068401. [PMID: 37625074 PMCID: PMC11146629 DOI: 10.1103/physrevlett.131.068401] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 03/20/2023] [Accepted: 06/09/2023] [Indexed: 08/27/2023]
Abstract
Many biological processes require timely communication between molecular components. Cells employ diverse physical channels to this end, transmitting information through diffusion, electrical depolarization, and mechanical waves among other strategies. Here we bound the energetic cost of transmitting information through these physical channels, in k_{B}T/bit, as a function of the size of the sender and receiver, their spatial separation, and the communication latency. These calculations provide an estimate for the energy costs associated with information processing arising from the physical constraints of the cellular environment, which we find to be many orders of magnitude larger than unity in natural units. From these calculations, we construct a phase diagram indicating where each strategy is most efficient. Our results suggest that intracellular information transfer may constitute a substantial energetic cost. This provides a new tool for understanding tradeoffs in cellular network function.
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Affiliation(s)
- Samuel J. Bryant
- Department of Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Benjamin B. Machta
- Department of Physics, Yale University and Quantitative Biology Institute, Yale University, New Haven, Connecticut 06511, USA
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8
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Balasubramaniam S, Somathilaka S, Sun S, Ratwatte A, Pierobon M. Realizing Molecular Machine Learning through Communications for Biological AI: Future Directions and Challenges. IEEE NANOTECHNOLOGY MAGAZINE 2023; 17:10-20. [PMID: 38855043 PMCID: PMC11160936 DOI: 10.1109/mnano.2023.3262099] [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] [Indexed: 06/11/2024]
Abstract
Artificial Intelligence (AI) and Machine Learning (ML) are weaving their way into the fabric of society, where they are playing a crucial role in numerous facets of our lives. As we witness the increased deployment of AI and ML in various types of devices, we benefit from their use into energy-efficient algorithms for low powered devices. In this paper, we investigate a scale and medium that is far smaller than conventional devices as we move towards molecular systems that can be utilized to perform machine learning functions, i.e., Molecular Machine Learning (MML). Fundamental to the operation of MML is the transport, processing, and interpretation of information propagated by molecules through chemical reactions. We begin by reviewing the current approaches that have been developed for MML, before we move towards potential new directions that rely on gene regulatory networks inside biological organisms as well as their population interactions to create neural networks. We then investigate mechanisms for training machine learning structures in biological cells based on calcium signaling and demonstrate their application to build an Analog to Digital Converter (ADC). Lastly, we look at potential future directions as well as challenges that this area could solve.
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Affiliation(s)
| | - Samitha Somathilaka
- School of Computing, University of Nebraska-Lincoln, NE, USA
- Walton Institute, South East Technological University, Ireland
| | - Sehee Sun
- School of Computing, University of Nebraska-Lincoln, NE, USA
| | - Adrian Ratwatte
- School of Computing, University of Nebraska-Lincoln, NE, USA
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9
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Bulthuis EP, Dieteren CEJ, Bergmans J, Berkhout J, Wagenaars JA, van de Westerlo EMA, Podhumljak E, Hink MA, Hesp LFB, Rosa HS, Malik AN, Lindert MKT, Willems PHGM, Gardeniers HJGE, den Otter WK, Adjobo-Hermans MJW, Koopman WJH. Stress-dependent macromolecular crowding in the mitochondrial matrix. EMBO J 2023; 42:e108533. [PMID: 36825437 PMCID: PMC10068333 DOI: 10.15252/embj.2021108533] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 01/10/2023] [Accepted: 01/19/2023] [Indexed: 02/25/2023] Open
Abstract
Macromolecules of various sizes induce crowding of the cellular environment. This crowding impacts on biochemical reactions by increasing solvent viscosity, decreasing the water-accessible volume and altering protein shape, function, and interactions. Although mitochondria represent highly protein-rich organelles, most of these proteins are somehow immobilized. Therefore, whether the mitochondrial matrix solvent exhibits macromolecular crowding is still unclear. Here, we demonstrate that fluorescent protein fusion peptides (AcGFP1 concatemers) in the mitochondrial matrix of HeLa cells display an elongated molecular structure and that their diffusion constant decreases with increasing molecular weight in a manner typical of macromolecular crowding. Chloramphenicol (CAP) treatment impaired mitochondrial function and reduced the number of cristae without triggering mitochondrial orthodox-to-condensed transition or a mitochondrial unfolded protein response. CAP-treated cells displayed progressive concatemer immobilization with increasing molecular weight and an eightfold matrix viscosity increase, compatible with increased macromolecular crowding. These results establish that the matrix solvent exhibits macromolecular crowding in functional and dysfunctional mitochondria. Therefore, changes in matrix crowding likely affect matrix biochemical reactions in a manner depending on the molecular weight of the involved crowders and reactants.
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Affiliation(s)
- Elianne P Bulthuis
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Cindy E J Dieteren
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands.,Department of Cell Biology and Electron Microscopy Center, Radboudumc, Nijmegen, The Netherlands
| | - Jesper Bergmans
- Department of Pediatrics, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands
| | - Job Berkhout
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Jori A Wagenaars
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Els M A van de Westerlo
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Emina Podhumljak
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Mark A Hink
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Laura F B Hesp
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Hannah S Rosa
- Department of Diabetes, King's College London, London, UK
| | - Afshan N Malik
- Department of Diabetes, King's College London, London, UK
| | - Mariska Kea-Te Lindert
- Department of Cell Biology and Electron Microscopy Center, Radboudumc, Nijmegen, The Netherlands
| | - Peter H G M Willems
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Han J G E Gardeniers
- Mesoscale Chemical Systems, University of Twente, Enschede, The Netherlands.,MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
| | - Wouter K den Otter
- MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.,Thermal and Fluid Engineering, Faculty of Engineering Technology, University of Twente, Enschede, The Netherlands
| | - Merel J W Adjobo-Hermans
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Werner J H Koopman
- Department of Pediatrics, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud Center for Mitochondrial Medicine (RCMM), Radboud University Medical Center (Radboudumc), Nijmegen, The Netherlands.,Human and Animal Physiology, Wageningen University, Wageningen, The Netherlands
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10
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Simas RG, Pessoa Junior A, Long PF. Mechanistic aspects of IPTG (isopropylthio-β-galactoside) transport across the cytoplasmic membrane of Escherichia coli-a rate limiting step in the induction of recombinant protein expression. J Ind Microbiol Biotechnol 2023; 50:kuad034. [PMID: 37849239 PMCID: PMC10639102 DOI: 10.1093/jimb/kuad034] [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: 05/20/2023] [Accepted: 10/16/2023] [Indexed: 10/19/2023]
Abstract
Coupling transcription of a cloned gene to the lac operon with induction by isopropylthio-β-galactoside (IPTG) has been a favoured approach for recombinant protein expression using Escherichia coli as a heterologous host for more than six decades. Despite a wealth of experimental data gleaned over this period, a quantitative relationship between extracellular IPTG concentration and consequent levels of recombinant protein expression remains surprisingly elusive across a broad spectrum of experimental conditions. This is because gene expression under lac operon regulation is tightly correlated with intracellular IPTG concentration due to allosteric regulation of the lac repressor protein (lacY). An in-silico mathematical model established that uptake of IPTG across the cytoplasmic membrane of E. coli by simple diffusion was negligible. Conversely, lacY mediated active transport was a rapid process, taking only some seconds for internal and external IPTG concentrations to equalize. Optimizing kcat and KM parameters by targeted mutation of the galactoside binding site in lacY could be a future strategy to improve the performance of recombinant protein expression. For example, if kcat were reduced whilst KM was increased, active transport of IPTG across the cytoplasmic membrane would be reduced, thereby lessening the metabolic burden on the cell and expediating accumulation of recombinant protein. The computational model described herein is made freely available and is amenable to optimize recombinant protein expression in other heterologous hosts. ONE-SENTENCE SUMMARY A computational model made freely available to optimize recombinant protein expression in Escherichia coli other heterologous hosts.
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Affiliation(s)
- Rodrigo G Simas
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
| | - Adalberto Pessoa Junior
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
| | - Paul F Long
- Faculty of Life Sciences & Medicine, King's College London, 150 Stamford Street, London SE1 9NH, UK
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, B16, 05508-000 São Paulo, SP, Brazil
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11
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Di Bari D, Timr S, Guiral M, Giudici-Orticoni MT, Seydel T, Beck C, Petrillo C, Derreumaux P, Melchionna S, Sterpone F, Peters J, Paciaroni A. Diffusive Dynamics of Bacterial Proteome as a Proxy of Cell Death. ACS CENTRAL SCIENCE 2023; 9:93-102. [PMID: 36712493 PMCID: PMC9881203 DOI: 10.1021/acscentsci.2c01078] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Indexed: 05/30/2023]
Abstract
Temperature variations have a big impact on bacterial metabolism and death, yet an exhaustive molecular picture of these processes is still missing. For instance, whether thermal death is determined by the deterioration of the whole or a specific part of the proteome is hotly debated. Here, by monitoring the proteome dynamics of E. coli, we clearly show that only a minor fraction of the proteome unfolds at the cell death. First, we prove that the dynamical state of the E. coli proteome is an excellent proxy for temperature-dependent bacterial metabolism and death. The proteome diffusive dynamics peaks at about the bacterial optimal growth temperature, then a dramatic dynamical slowdown is observed that starts just below the cell's death temperature. Next, we show that this slowdown is caused by the unfolding of just a small fraction of proteins that establish an entangling interprotein network, dominated by hydrophobic interactions, across the cytoplasm. Finally, the deduced progress of the proteome unfolding and its diffusive dynamics are both key to correctly reproduce the E. coli growth rate.
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Affiliation(s)
- Daniele Di Bari
- Università
degli Studi di Perugia, Dipartimento di
Fisica e Geologia, Via
A. Pascoli, 06123Perugia PG, Italy
- Université
Grenoble Alpes, CNRS, Laboratoire Interdisciplinaire de Physique, 38400Saint-Martin-d’Héres, France
- Institut
Laue-Langevin, 38000Grenoble, France
| | - Stepan Timr
- Laboratoire
de Biochimie Théorique (UPR9080), CNRS, Université de Paris Cité, 13 Rue Pierre et Marie Curie, 75005Paris, France
- Institut
de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 Rue Pierre et Marie Curie, 75005Paris, France
- J.
Heyrovský
Institute of Physical Chemistry, Czech Academy
of Sciences, 182 23Prague 8, Czechia
| | - Marianne Guiral
- Laboratoire
de Bioénergétique et Ingénierie des Protéines, BIP, CNRS, Aix-Marseille Université, 13400Marseille, France
| | | | - Tilo Seydel
- Institut
Laue-Langevin, 38000Grenoble, France
| | | | - Caterina Petrillo
- Università
degli Studi di Perugia, Dipartimento di
Fisica e Geologia, Via
A. Pascoli, 06123Perugia PG, Italy
| | - Philippe Derreumaux
- Laboratoire
de Biochimie Théorique (UPR9080), CNRS, Université de Paris Cité, 13 Rue Pierre et Marie Curie, 75005Paris, France
- Institut
de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 Rue Pierre et Marie Curie, 75005Paris, France
- Institut Universitaire de France, 75005Paris, France
| | - Simone Melchionna
- ISC-CNR,
Dipartimento di Fisica, Università
Sapienza, 00185Rome, Italy
- Lexma
Technology1337 Massachusetts
Avenue, Arlington, Massachusetts02476, United States
| | - Fabio Sterpone
- Laboratoire
de Biochimie Théorique (UPR9080), CNRS, Université de Paris Cité, 13 Rue Pierre et Marie Curie, 75005Paris, France
- Institut
de Biologie Physico-Chimique, Fondation Edmond de Rothschild, 13 Rue Pierre et Marie Curie, 75005Paris, France
| | - Judith Peters
- Université
Grenoble Alpes, CNRS, Laboratoire Interdisciplinaire de Physique, 38400Saint-Martin-d’Héres, France
- Institut
Laue-Langevin, 38000Grenoble, France
- Institut Universitaire de France, 75005Paris, France
| | - Alessandro Paciaroni
- Università
degli Studi di Perugia, Dipartimento di
Fisica e Geologia, Via
A. Pascoli, 06123Perugia PG, Italy
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12
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Liew WJM, Wong YS, Parikh AN, Venkatraman SS, Cao Y, Czarny B. Cell-mimicking polyethylene glycol-diacrylate based nanolipogel for encapsulation and delivery of hydrophilic biomolecule. Front Bioeng Biotechnol 2023; 11:1113236. [PMID: 36733962 PMCID: PMC9888760 DOI: 10.3389/fbioe.2023.1113236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/05/2023] [Indexed: 01/18/2023] Open
Abstract
Lipid based nanoparticulate formulations have been widely used for the encapsulation and sustain release of hydrophilic drugs, but they still face challenges such as high initial burst release. Nanolipogel (NLG) emerges as a potential system to encapsulate and deliver hydrophilic drug while suppressing its initial burst release. However, there is a lack of characterization of the drug release mechanism from NLGs. In this work, we present a study on the release mechanism of hydrophilic Dextran-Fluorescein Isothiocyanate (DFITC) from Poly (ethylene glycol) Diacrylate (PEGDA) NLGs by using different molecular weights of PEGDA to vary the mesh size of the nanogel core, drawing inspiration from the macromolecular crowding effect in cells, which can be viewed as a mesh network of undefined sizes. The effect is then further characterized and validated by studying the diffusion of DFITC within the nanogel core using Fluorescence Recovery after Photobleaching (FRAP), on our newly developed cell derived microlipogels (MLG). This is in contrast to conventional FRAP works on cells or bulk hydrogels, which is limited in our application. Our work showed that the mesh size of the NLGs can be controlled by using different Mw of PEGDA, such as using a smaller MW to achieve higher crosslinking density, which will lead to having smaller mesh size for the crosslinked nanogel, and the release of hydrophilic DFITC can be sustained while suppressing the initial burst release, up to 10-fold more for crosslinked PEGDA 575 NLGs. This is further validated by FRAP which showed that the diffusion of DFITC is hindered by the decreasing mesh sizes in the NLGs, as a result of lower mobile fractions. These findings will be useful for guiding the design of PEGDA NLGs to have different degree of suppression of the initial burst release as well as the cumulative release, for a wide array of applications. This can also be extended to other different types of nanogel cores and other nanogel core-based nanoparticles for encapsulation and release of hydrophilic biomolecules.
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Affiliation(s)
- Wen Jie Melvin Liew
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Yee Shan Wong
- Biomedical Engineering, School of Engineering, Temasek Polytechnic, Singapore, Singapore
| | - Atul N. Parikh
- Biomedical Engineering and Materials Science and Engineering, University of California, Davis, Davis, CA, United States
| | - Subbu S. Venkatraman
- School of Materials Science and Engineering, National University of Singapore, Singapore, Singapore
| | - Ye Cao
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China,*Correspondence: Ye Cao, ; Bertrand Czarny,
| | - Bertrand Czarny
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore,*Correspondence: Ye Cao, ; Bertrand Czarny,
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13
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Fullstone G. Rapid Particle-Based Simulations of Cellular Signalling with the FLAME-Accelerated Signalling Tool (FaST) and GPUs. Methods Mol Biol 2023; 2634:191-212. [PMID: 37074580 DOI: 10.1007/978-1-0716-3008-2_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Cellular signalling is a vital process in living organisms for coordinating highly diverse responses to various stimuli. Particle-based modelling excels in its ability to model complex features of cellular signalling pathways including stochasticity, spatial effects, and heterogeneity, thus improving our understanding of critical decision processes in biology. Yet, particle-based modelling is computationally prohibitive to implement. We recently developed FaST (FLAME-accelerated signalling tool), a software tool that harnesses the power of high-performance computation to reduce the computational burden of particle-based modelling. In particular, employing the unique massively parallel architecture of graphic processing units (GPUs) provided extreme speed ups of simulations by >650-fold. In this chapter, we provide a step-by-step walkthrough of how to use FaST to create GPU-accelerated simulations of a simple cellular signalling network. We further explore how the flexibility of FaST can be used to implement entirely customized simulations while still including the intrinsic speed up advantages of GPU-based parallelization.
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Affiliation(s)
- Gavin Fullstone
- Institute for Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.
- Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany.
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14
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Sun C, Meng X, Sun F, Zhang J, Tu M, Chang JS, Reungsang A, Xia A, Ragauskas AJ. Advances and perspectives on mass transfer and enzymatic hydrolysis in the enzyme-mediated lignocellulosic biorefinery: A review. Biotechnol Adv 2023; 62:108059. [PMID: 36402253 DOI: 10.1016/j.biotechadv.2022.108059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
Enzymatic hydrolysis is a critical process for the cellulase-mediated lignocellulosic biorefinery to produce sugar syrups that can be converted into a whole range of biofuels and biochemicals. Such a process operating at high-solid loadings (i.e., scarcely any free water or roughly ≥ 15% solids, w/w) is considered more economically feasible, as it can generate a high sugar concentration at low operation and capital costs. However, this approach remains restricted and incurs "high-solid effects", ultimately causing the lower hydrolysis yields with increasing solid loadings. The lack of available water leads to a highly viscous system with impaired mixing that exhibits strong transfer resistance and reaction limitation imposed on enzyme action. Evidently, high-solid enzymatic hydrolysis involves multi-scale mass transfer and multi-phase enzyme reaction, and thus requires a synergistic perspective of transfer and biotransformation to assess the interactions among water, biomass components, and cellulase enzymes. Porous particle characteristics of biomass and its interface properties determine the water form and distribution state surrounding the particles, which are summarized in this review aiming to identify the water-driven multi-scale/multi-phase bioprocesses. Further aided by the cognition of rheological behavior of biomass slurry, solute transfer theories, and enzyme kinetics, the coupling effects of flow-transfer-reaction are revealed under high-solid conditions. Based on the above basic features, this review lucidly explains the causes of high-solid hydrolysis hindrances, highlights the mismatched issues between transfer and reaction, and more importantly, presents the advanced strategies for transfer and reaction enhancements from the viewpoint of process optimization, reactor design, as well as enzyme/auxiliary additive customization.
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Affiliation(s)
- Chihe Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xianzhi Meng
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Fubao Sun
- Key Laboratory of Industrial Biotechnology of MOE, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Junhua Zhang
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China
| | - Maobing Tu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Jo-Shu Chang
- Department of Chemical and Materials Engineering, Tunghai University, Taichung 407, Taiwan
| | - Alissara Reungsang
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Ao Xia
- Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing 400044, China
| | - Arthur J Ragauskas
- Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, The University of Tennessee, Knoxville, TN 37996, USA; Joint Institute of Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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15
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Krassner MM, Kauffman J, Sowa A, Cialowicz K, Walsh S, Farrell K, Crary JF, McKenzie AT. Postmortem changes in brain cell structure: a review. FREE NEUROPATHOLOGY 2023; 4:4-10. [PMID: 37384330 PMCID: PMC10294569 DOI: 10.17879/freeneuropathology-2023-4790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/15/2023] [Indexed: 06/30/2023]
Abstract
Brain cell structure is a key determinant of neural function that is frequently altered in neurobiological disorders. Following the global loss of blood flow to the brain that initiates the postmortem interval (PMI), cells rapidly become depleted of energy and begin to decompose. To ensure that our methods for studying the brain using autopsy tissue are robust and reproducible, there is a critical need to delineate the expected changes in brain cell morphometry during the PMI. We searched multiple databases to identify studies measuring the effects of PMI on the morphometry (i.e. external dimensions) of brain cells. We screened 2119 abstracts, 361 full texts, and included 172 studies. Mechanistically, fluid shifts causing cell volume alterations and vacuolization are an early event in the PMI, while the loss of the ability to visualize cell membranes altogether is a later event. Decomposition rates are highly heterogenous and depend on the methods for visualization, the structural feature of interest, and modifying variables such as the storage temperature or the species. Geometrically, deformations of cell membranes are common early events that initiate within minutes. On the other hand, topological relationships between cellular features appear to remain intact for more extended periods. Taken together, there is an uncertain period of time, usually ranging from several hours to several days, over which cell membrane structure is progressively lost. This review may be helpful for investigators studying human postmortem brain tissue, wherein the PMI is an unavoidable aspect of the research.
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Affiliation(s)
- Margaret M. Krassner
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Friedman Brain Institute, Departments of Pathology, Neuroscience and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neuropathology Brain Bank & Research Core and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Justin Kauffman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Friedman Brain Institute, Departments of Pathology, Neuroscience and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neuropathology Brain Bank & Research Core and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Allison Sowa
- Microscopy and Advanced Bioimaging Core, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Katarzyna Cialowicz
- Microscopy and Advanced Bioimaging Core, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Samantha Walsh
- Hunter College Libraries, CUNY Hunter College, New York, NY
| | - Kurt Farrell
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Friedman Brain Institute, Departments of Pathology, Neuroscience and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neuropathology Brain Bank & Research Core and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - John F. Crary
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Friedman Brain Institute, Departments of Pathology, Neuroscience and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neuropathology Brain Bank & Research Core and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Andrew T. McKenzie
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Friedman Brain Institute, Departments of Pathology, Neuroscience and Artificial Intelligence & Human Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Neuropathology Brain Bank & Research Core and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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16
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Lyu Z, Yahashiri A, Yang X, McCausland JW, Kaus GM, McQuillen R, Weiss DS, Xiao J. FtsN maintains active septal cell wall synthesis by forming a processive complex with the septum-specific peptidoglycan synthases in E. coli. Nat Commun 2022; 13:5751. [PMID: 36180460 PMCID: PMC9525312 DOI: 10.1038/s41467-022-33404-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 09/16/2022] [Indexed: 01/06/2023] Open
Abstract
FtsN plays an essential role in promoting the inward synthesis of septal peptidoglycan (sPG) by the FtsWI complex during bacterial cell division. How it achieves this role is unclear. Here we use single-molecule tracking to investigate FtsN's dynamics during sPG synthesis in E. coli. We show that septal FtsN molecules move processively at ~9 nm s-1, the same as FtsWI molecules engaged in sPG synthesis (termed sPG-track), but much slower than the ~30 nm s-1 speed of inactive FtsWI molecules coupled to FtsZ's treadmilling dynamics (termed FtsZ-track). Importantly, processive movement of FtsN is exclusively coupled to sPG synthesis and is required to maintain active sPG synthesis by FtsWI. Our findings indicate that FtsN is part of the FtsWI sPG synthesis complex, and that while FtsN is often described as a "trigger" for the initiation for cell wall constriction, it must remain part of the processive FtsWI complex to maintain sPG synthesis activity.
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Affiliation(s)
- Zhixin Lyu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Atsushi Yahashiri
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Xinxing Yang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
- The Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Joshua W McCausland
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Gabriela M Kaus
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Ryan McQuillen
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - David S Weiss
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
| | - Jie Xiao
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
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17
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Palumbo RJ, McKean N, Leatherman E, Namitz KEW, Connell L, Wolfe A, Moody K, Gostinčar C, Gunde-Cimerman N, Bah A, Hanes SD. Coevolution of the Ess1-CTD axis in polar fungi suggests a role for phase separation in cold tolerance. SCIENCE ADVANCES 2022; 8:eabq3235. [PMID: 36070379 PMCID: PMC9451162 DOI: 10.1126/sciadv.abq3235] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/21/2022] [Indexed: 06/14/2023]
Abstract
Most of the world's biodiversity lives in cold (-2° to 4°C) and hypersaline environments. To understand how cells adapt to such conditions, we isolated two key components of the transcription machinery from fungal species that live in extreme polar environments: the Ess1 prolyl isomerase and its target, the carboxy-terminal domain (CTD) of RNA polymerase II. Polar Ess1 enzymes are conserved and functional in the model yeast, Saccharomyces cerevisiae. By contrast, polar CTDs diverge from the consensus (YSPTSPS)26 and are not fully functional in S. cerevisiae. These CTDs retain the critical Ess1 Ser-Pro target motifs, but substitutions at Y1, T4, and S7 profoundly affected their ability to undergo phase separation in vitro and localize in vivo. We propose that environmentally tuned phase separation by the CTD and other intrinsically disordered regions plays an adaptive role in cold tolerance by concentrating enzymes and substrates to overcome energetic barriers to metabolic activity.
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Affiliation(s)
- Ryan J. Palumbo
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Nathan McKean
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Erinn Leatherman
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Kevin E. W. Namitz
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Laurie Connell
- School of Marine Sciences and Department of Molecular and Biomedical Sciences, University of Maine, Orono, ME 04469, USA
| | - Aaron Wolfe
- Ichor Life Sciences Inc., 2651 US Route 11, LaFayette, NY 13084, USA
- Lewis School of Health Sciences, Clarkson University, 8 Clarkson Avenue, Potsdam, NY 13699, USA
- The BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
| | - Kelsey Moody
- Ichor Life Sciences Inc., 2651 US Route 11, LaFayette, NY 13084, USA
- Lewis School of Health Sciences, Clarkson University, 8 Clarkson Avenue, Potsdam, NY 13699, USA
- The BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
| | - Cene Gostinčar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Nina Gunde-Cimerman
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Alaji Bah
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
| | - Steven D. Hanes
- Department of Biochemistry and Molecular Biology, SUNY-Upstate Medical University, Syracuse, NY 13210, USA
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18
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Abstract
Despite having been studied for decades, first passage processes remain an active area of research. In this contribution we examine a particle diffusing in an annulus with an inner absorbing boundary and an outer reflective boundary. We obtain analytic expressions for the joint distribution of the hitting time and the hitting angle in two and three dimensions. For certain configurations we observe a ``diffusive echo", i.e. two well-defined maxima in the first passage time distribution to a targeted position on the absorbing boundary. This effect, which results from the interplay between the starting location and the environmental constraints, may help to significantly increase the efficiency of the random search by generating a high, sustained flux to the targeted position over a short period. Finally, we examine the corresponding one-dimensional system for which there is no well-defined echo. In a confined system, the flux integrated over all target positions always displays a shoulder. This does not, however, guarantee the presence of an echo in the joint distribution.
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Affiliation(s)
| | - Julian Talbot
- Laboratoire de Physique Théorique de la Matière Condensée (LPTMC), Sorbonne Universités, France
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19
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Śmigiel WM, Mantovanelli L, Linnik DS, Punter M, Silberberg J, Xiang L, Xu K, Poolman B. Protein diffusion in Escherichia coli cytoplasm scales with the mass of the complexes and is location dependent. SCIENCE ADVANCES 2022; 8:eabo5387. [PMID: 35960807 PMCID: PMC9374337 DOI: 10.1126/sciadv.abo5387] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/28/2022] [Indexed: 05/30/2023]
Abstract
We analyze the structure of the cytoplasm by performing single-molecule displacement mapping on a diverse set of native cytoplasmic proteins in exponentially growing Escherichia coli. We evaluate the method for application in small compartments and find that confining effects of the cell membrane affect the diffusion maps. Our analysis reveals that protein diffusion at the poles is consistently slower than in the center of the cell, i.e., to an extent greater than the confining effect of the cell membrane. We also show that the diffusion coefficient scales with the mass of the used probes, taking into account the oligomeric state of the proteins, while parameters such as native protein abundance or the number of protein-protein interactions do not correlate with the mobility of the proteins. We argue that our data paint the prokaryotic cytoplasm as a compartment with subdomains in which the diffusion of macromolecules changes with the perceived viscosity.
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Affiliation(s)
- Wojciech M. Śmigiel
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Luca Mantovanelli
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Dmitrii S. Linnik
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Michiel Punter
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Jakob Silberberg
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | - Limin Xiang
- Department of Chemistry, UC Berkeley, Stanley Hall, Berkeley, CA 94720, USA
| | - Ke Xu
- Department of Chemistry, UC Berkeley, Stanley Hall, Berkeley, CA 94720, USA
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
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20
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Schmitz TC, van Doeselaar M, Tryfonidou MA, Ito K. Detergent-Free Decellularization of Notochordal Cell-Derived Matrix Yields a Regenerative, Injectable, and Swellable Biomaterial. ACS Biomater Sci Eng 2022; 8:3912-3923. [PMID: 35942885 PMCID: PMC9472229 DOI: 10.1021/acsbiomaterials.2c00790] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Porcine notochordal cell-derived matrix (NCM) has anti-inflammatory
and regenerative effects on degenerated intervertebral discs. For
its clinical use, safety must be assured. The porcine DNA is concerning
because of (1) the transmission of endogenous retroviruses and (2)
the inflammatory potential of cell-free DNA. Here, we present a simple,
detergent-free protocol: tissue lyophilization lyses cells, and matrix
integrity is preserved by limiting swelling during decellularization.
DNA is digested quickly by a high nuclease concentration, followed
by a short washout. Ninety-four percent of DNA was removed, and there
was no loss of glycosaminoglycans or collagen. Forty-three percent
of the total proteins remained in the decellularized NCM (dNCM). dNCM
stimulated as much GAG production as NCM in nucleus pulposus cells
but lost some anti-inflammatory effects. Reconstituted pulverized
dNCM yielded a soft, shear-thinning biomaterial with a swelling ratio
of 350% that also acted as an injectable cell carrier (cell viability
>70%). dNCM can therefore be used as the basis for future biomaterials
aimed at disc regeneration on a biological level and may restore joint
mechanics by creating swelling pressure within the intervertebral
disc.
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Affiliation(s)
- Tara C Schmitz
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
| | - Marina van Doeselaar
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
| | - Marianna A Tryfonidou
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, Utrecht 3584 CM, Netherlands
| | - Keita Ito
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
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21
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Słyk E, Skóra T, Kondrat S. How macromolecules softness affects diffusion under crowding. SOFT MATTER 2022; 18:5366-5370. [PMID: 35833511 DOI: 10.1039/d2sm00357k] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Diffusion in a macromolecularly crowded environment is essential for many intracellular processes, from metabolism and catalysis to gene transcription and translation. So far, theoretical and experimental work has focused on anomalous subdiffusion, and the effects of interactions, shapes, and composition, while the compactness or softness of macromolecules has received less attention. Herein, we use Brownian dynamics simulations to study how the softness of crowders affects macromolecular diffusion. We find that in most cases, soft crowders slow down the diffusion less effectively than hard crowders like Ficoll. For instance, at a 30% occupied volume fraction, the diffusion in Ficoll70 is about 20% slower than in soft crowders of the same size. However, our simulations indicate that elongated macromolecules, such as double-stranded DNA pieces, can diffuse comparably or even faster in hard crowders. We relate these effects to the volume excluded by soft and hard crowders to different tracers. Our results show that the softness and shape of macromolecules are crucial factors determining diffusion under crowding, relevant to diverse intracellular environments.
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Affiliation(s)
- Edyta Słyk
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland.
- Department of Theoretical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, 20-031 Lublin, Poland
| | - Tomasz Skóra
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland.
| | - Svyatoslav Kondrat
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland.
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany
- IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
- Institut für Computerphysik, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany
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22
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Huang Z, Sun L, Lu G, Liu H, Zhai Z, Feng S, Gao J, Chen C, Qing C, Fang M, Chen B, Fu J, Wang X, Chen G. Rapid regulations of metabolic reactions in
Escherichia coli
via light‐responsive enzyme redistribution. Biotechnol J 2022; 17:e2200129. [DOI: 10.1002/biot.202200129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/14/2022] [Accepted: 05/25/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Zikang Huang
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Lize Sun
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Genzhe Lu
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Hongrui Liu
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
- Johns Hopkins University School of Medicine Baltimore MD 21205 USA
| | - Zihan Zhai
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Site Feng
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Ji Gao
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Chunyu Chen
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Chuheng Qing
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Meng Fang
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Bowen Chen
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Jiale Fu
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
| | - Xuan Wang
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
- Center for Synthetic and Systems Biology Tsinghua University Beijing 100084 China
- Tsinghua‐Peking Center for Life Sciences Beijing 100084 China
| | - Guo‐Qiang Chen
- School of Life Sciences Tsinghua University Beijing 100084 China
- Tsinghua iGEM Team 2019 Beijing 100084 China
- Center for Synthetic and Systems Biology Tsinghua University Beijing 100084 China
- Tsinghua‐Peking Center for Life Sciences Beijing 100084 China
- MOE Key Lab of Industrial Biocatalysts Department of Chemical Engineering Tsinghua University Beijing 100084 China
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23
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Li C, Zhang X, Dong M, Han X. Progress on Crowding Effect in Cell-like Structures. MEMBRANES 2022; 12:membranes12060593. [PMID: 35736300 PMCID: PMC9228500 DOI: 10.3390/membranes12060593] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 12/10/2022]
Abstract
Several biological macromolecules, such as proteins, nucleic acids, and polysaccharides, occupy about 30% of the space in cells, resulting in a crowded macromolecule environment. The crowding effect within cells exerts an impact on the functions of biological components, the assembly behavior of biomacromolecules, and the thermodynamics and kinetics of metabolic reactions. Cell-like structures provide confined and independent compartments for studying the working mechanisms of cells, which can be used to study the physiological functions arising from the crowding effect of macromolecules in cells. This article mainly summarizes the progress of research on the macromolecular crowding effects in cell-like structures. It includes the effects of this crowding on actin assembly behavior, tubulin aggregation behavior, and gene expression. The challenges and future trends in this field are presented at the end of the paper.
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Affiliation(s)
- Chao Li
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin 150001, China; (C.L.); (X.Z.)
| | - Xiangxiang Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin 150001, China; (C.L.); (X.Z.)
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
- Correspondence: (M.D.); (X.H.)
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin 150001, China; (C.L.); (X.Z.)
- Correspondence: (M.D.); (X.H.)
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24
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Single molecule tracking of bacterial cell surface cytochromes reveals dynamics that impact long-distance electron transport. Proc Natl Acad Sci U S A 2022; 119:e2119964119. [PMID: 35503913 PMCID: PMC9171617 DOI: 10.1073/pnas.2119964119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiheme cytochromes in Shewanella oneidensis MR-1 transport electrons across the cell wall, in a process called extracellular electron transfer. These electron conduits can also enable electron transport along and between cells. While the underlying mechanism is thought to involve a combination of electron hopping and lateral diffusion of cytochromes along membranes, these diffusive dynamics have never been observed in vivo. Here, we observe the mobility of quantum dot-labeled cytochromes on living cell surfaces and membrane nanowires, quantify their diffusion with single-particle tracking techniques, and simulate the contribution of these dynamics to electron transport. This work reveals the impact of redox molecule dynamics on bacterial electron transport, with implications for understanding and harnessing this process in the environment and bioelectronics. Using a series of multiheme cytochromes, the metal-reducing bacterium Shewanella oneidensis MR-1 can perform extracellular electron transfer (EET) to respire redox-active surfaces, including minerals and electrodes outside the cell. While the role of multiheme cytochromes in transporting electrons across the cell wall is well established, these cytochromes were also recently found to facilitate long-distance (micrometer-scale) redox conduction along outer membranes and across multiple cells bridging electrodes. Recent studies proposed that long-distance conduction arises from the interplay of electron hopping and cytochrome diffusion, which allows collisions and electron exchange between cytochromes along membranes. However, the diffusive dynamics of the multiheme cytochromes have never been observed or quantified in vivo, making it difficult to assess their hypothesized contribution to the collision-exchange mechanism. Here, we use quantum dot labeling, total internal reflection fluorescence microscopy, and single-particle tracking to quantify the lateral diffusive dynamics of the outer membrane-associated decaheme cytochromes MtrC and OmcA, two key components of EET in S. oneidensis. We observe confined diffusion behavior for both quantum dot-labeled MtrC and OmcA along cell surfaces (diffusion coefficients DMtrC = 0.0192 ± 0.0018 µm2/s, DOmcA = 0.0125 ± 0.0024 µm2/s) and the membrane extensions thought to function as bacterial nanowires. We find that these dynamics can trace a path for electron transport via overlap of cytochrome trajectories, consistent with the long-distance conduction mechanism. The measured dynamics inform kinetic Monte Carlo simulations that combine direct electron hopping and redox molecule diffusion, revealing significant electron transport rates along cells and membrane nanowires.
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25
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Frallicciardi J, Melcr J, Siginou P, Marrink SJ, Poolman B. Membrane thickness, lipid phase and sterol type are determining factors in the permeability of membranes to small solutes. Nat Commun 2022; 13:1605. [PMID: 35338137 PMCID: PMC8956743 DOI: 10.1038/s41467-022-29272-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 03/02/2022] [Indexed: 12/16/2022] Open
Abstract
Cell membranes provide a selective semi-permeable barrier to the passive transport of molecules. This property differs greatly between organisms. While the cytoplasmic membrane of bacterial cells is highly permeable for weak acids and glycerol, yeasts can maintain large concentration gradients. Here we show that such differences can arise from the physical state of the plasma membrane. By combining stopped-flow kinetic measurements with molecular dynamics simulations, we performed a systematic analysis of the permeability of a variety of small molecules through synthetic membranes of different lipid composition to obtain detailed molecular insight into the permeation mechanisms. While membrane thickness is an important parameter for the permeability through fluid membranes, the largest differences occur when the membranes transit from the liquid-disordered to liquid-ordered and/or to gel state, which is in agreement with previous work on passive diffusion of water. By comparing our results with in vivo measurements from yeast, we conclude that the yeast membrane exists in a highly ordered and rigid state, which is comparable to synthetic saturated DPPC-sterol membranes. Membrane permeability of small molecules depends on the composition of the lipid bilayer. Here, authors compare permeability measured on membranes in different physical states and conclude that the yeast membrane exists in a highly ordered phase.
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Affiliation(s)
- Jacopo Frallicciardi
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands
| | - Josef Melcr
- Department of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands
| | - Pareskevi Siginou
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands
| | - Siewert J Marrink
- Department of Biophysical Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands.
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, the Netherlands.
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26
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Comparative study of SARS-CoV-2 infection in different cell types: Biophysical-computational approach to the role of potential receptors. Comput Biol Med 2022; 142:105245. [PMID: 35077937 PMCID: PMC8770263 DOI: 10.1016/j.compbiomed.2022.105245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/07/2022] [Accepted: 01/16/2022] [Indexed: 12/17/2022]
Abstract
Cellular susceptibility to SARS-CoV-2 infection in the respiratory tract has been associated with the ability of the virus to interact with potential receptors on the host membrane. We have modeled viral dynamics by simulating various cellular systems and artificial conditions, including macromolecular crowding, based on experimental and transcriptomic data to infer parameters associated with viral growth and predict cell susceptibility. We have accomplished this based on the type, number and level of expression of the angiotensin-converting enzyme 2 (ACE2), transmembrane serine 2 (TMPRSS2), basigin2 (CD147), FURIN protease, neuropilin 1 (NRP1) or other less studied candidate receptors such as heat shock protein A5 (HSPA5) and angiotensin II receptor type 2 (AGTR2). In parallel, we studied the effect of simulated artificial environments on the accessibility to said proposed receptors. In addition, viral kinetic behavior dependent on the degree of cellular susceptibility was predicted. The latter was observed to be more influenced by the type of proteins and expression level, than by the number of potential proteins associated with the SARS CoV-2 infection. We predict a greater theoretical propensity to susceptibility in cell lines such as NTERA-2, SCLC-21H, HepG2 and Vero6, and a lower theoretical propensity in lines such as CaLu3, RT4, HEK293, A549 and U-251MG. An important relationship was observed between expression levels, protein diffusivity, and thermodynamically favorable interactions between host proteins and the viral spike, suggesting potential sites of early infection other than the lungs. This research is expected to stimulate future quantitative experiments and promote systematic investigation of the effect of crowding presented here.
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27
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Diffusion control in biochemical specificity. Biophys J 2022; 121:1541-1548. [PMID: 35278424 PMCID: PMC9072584 DOI: 10.1016/j.bpj.2022.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/28/2021] [Accepted: 03/04/2022] [Indexed: 11/20/2022] Open
Abstract
Biochemical specificity is critical in enzyme function, evolution, and engineering. Here we employ an established kinetic model to dissect the effects of reactant geometry and diffusion on product formation speed and accuracy in the presence of cognate (correct) and near-cognate (incorrect) substrates. Using this steady-state model for spherical geometries, we find that, for distinct kinetic regimes, the speed and accuracy of the reactions are optimized on different regions of the geometric landscape. From this model we deduce that accuracy can be strongly dependent on reactant geometric properties even for chemically limited reactions. Notably, substrates with a specific geometry and reactivity can be discriminated by the enzyme with higher efficacy than others through purely diffusive effects. For similar cognate and near-cognate substrate geometries (as is the case for polymerases or the ribosome), we observe that speed and accuracy are maximized in opposing regions of the geometric landscape. We also show that, in relevant environments, diffusive effects on accuracy can be substantial even far from extreme kinetic conditions. Finally, we find how reactant chemical discrimination and diffusion can be related to simultaneously optimize steady-state flux and accuracy. These results highlight how diffusion and geometry can be employed to enhance reaction speed and discrimination, and similarly how they impose fundamental restraints on these quantities.
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28
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Chun SY, Son MK, Park CR, Lim C, Kim HI, Kwak K, Cho M. Direct observation of protein structural transitions through entire amyloid aggregation processes in water using 2D-IR spectroscopy. Chem Sci 2022; 13:4482-4489. [PMID: 35656138 PMCID: PMC9020176 DOI: 10.1039/d1sc06047c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/18/2022] [Indexed: 12/02/2022] Open
Abstract
Amyloid proteins that undergo self-assembly to form insoluble fibrillar aggregates have attracted much attention due to their role in biological and pathological significance in amyloidosis. This study aims to understand the amyloid aggregation dynamics of insulin (INS) in H2O using two-dimensional infrared (2D-IR) spectroscopy. Conventional IR studies have been performed in D2O to avoid spectral congestion despite distinct H–D isotope effects. We observed a slowdown of the INS fibrillation process in D2O compared to that in H2O. The 2D-IR results reveal that different quaternary structures of INS at the onset of the nucleation phase caused the distinct fibrillation pathways of INS in H2O and D2O. A few different biophysical analysis, including solution-phase small-angle X-ray scattering combined with molecular dynamics simulations and other spectroscopic techniques, support our 2D-IR investigation results, providing insight into mechanistic details of distinct structural transition dynamics of INS in water. We found the delayed structural transition in D2O is due to the kinetic isotope effect at an early stage of fibrillation of INS in D2O, i.e., enhanced dimer formation of INS in D2O. Our 2D-IR and biophysical analysis provide insight into mechanistic details of structural transition dynamics of INS in water. This study demonstrates an innovative 2D-IR approach for studying protein dynamics in H2O, which will open the way for observing protein dynamics under biological conditions without IR spectroscopic interference by water vibrations. This study aims to understand the structural transition dynamics of INS during amyloid aggregation in H2O using 2D-IR spectroscopy. The results show that distinct fibrillations in D2O and H2O originated from different quaternary structures of INS.![]()
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Affiliation(s)
- So Yeon Chun
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) Seoul 02841 Republic of Korea
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
| | - Myung Kook Son
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
- Center for Proteogenome Research, Korea University Seoul 02841 Republic of Korea
- Single Cell Analysis Laboratory, Korea University Seoul 02841 Republic of Korea
| | - Chae Ri Park
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
- Center for Proteogenome Research, Korea University Seoul 02841 Republic of Korea
- Single Cell Analysis Laboratory, Korea University Seoul 02841 Republic of Korea
| | - Chaiho Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) Seoul 02841 Republic of Korea
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
| | - Hugh I Kim
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
- Center for Proteogenome Research, Korea University Seoul 02841 Republic of Korea
- Single Cell Analysis Laboratory, Korea University Seoul 02841 Republic of Korea
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) Seoul 02841 Republic of Korea
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) Seoul 02841 Republic of Korea
- Department of Chemistry, Korea University Seoul 02841 Republic of Korea
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29
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Bellotto N, Agudo-Canalejo J, Colin R, Golestanian R, Malengo G, Sourjik V. Dependence of diffusion in Escherichia coli cytoplasm on protein size, environmental conditions, and cell growth. eLife 2022; 11:82654. [PMID: 36468683 PMCID: PMC9810338 DOI: 10.7554/elife.82654] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Inside prokaryotic cells, passive translational diffusion typically limits the rates with which cytoplasmic proteins can reach their locations. Diffusion is thus fundamental to most cellular processes, but the understanding of protein mobility in the highly crowded and non-homogeneous environment of a bacterial cell is still limited. Here, we investigated the mobility of a large set of proteins in the cytoplasm of Escherichia coli, by employing fluorescence correlation spectroscopy (FCS) combined with simulations and theoretical modeling. We conclude that cytoplasmic protein mobility could be well described by Brownian diffusion in the confined geometry of the bacterial cell and at the high viscosity imposed by macromolecular crowding. We observed similar size dependence of protein diffusion for the majority of tested proteins, whether native or foreign to E. coli. For the faster-diffusing proteins, this size dependence is well consistent with the Stokes-Einstein relation once taking into account the specific dumbbell shape of protein fusions. Pronounced subdiffusion and hindered mobility are only observed for proteins with extensive interactions within the cytoplasm. Finally, while protein diffusion becomes markedly faster in actively growing cells, at high temperature, or upon treatment with rifampicin, and slower at high osmolarity, all of these perturbations affect proteins of different sizes in the same proportions, which could thus be described as changes of a well-defined cytoplasmic viscosity.
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Affiliation(s)
- Nicola Bellotto
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | | | - Remy Colin
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Ramin Golestanian
- Max Planck Institute for Dynamics and Self-OrganizationGöttingenGermany,Rudolf Peierls Centre for Theoretical Physics, University of OxfordOxfordUnited Kingdom
| | - Gabriele Malengo
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO)MarburgGermany
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30
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Single molecule dynamics of DNA receptor ComEA, membrane permease ComEC and taken up DNA in competent Bacillus subtilis cells. J Bacteriol 2021; 204:e0057221. [PMID: 34928178 DOI: 10.1128/jb.00572-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In competent Gram-negative and Gram-positive bacteria, double stranded DNA is taken up through the outer cell membrane and/or the cell wall, and is bound by ComEA, which in Bacillus subtilis is a membrane protein. DNA is converted to single stranded DNA, and transported through the cell membrane via ComEC. We show that in Bacillus subtilis, the C-terminus of ComEC, thought to act as a nuclease, is not only important for DNA uptake, as judged from a loss of transformability, but also for the localization of ComEC to the cell pole and its mobility within the cell membrane. Using single molecule tracking, we show that only 13% of ComEC molecules are statically localised at the pole, while 87% move throughout the cell membrane. These experiments suggest that recruitment of ComEC to the cell pole is mediated by a diffusion/capture mechanism. Mutation of a conserved aspartate residue in the C-terminus, likely affecting metal binding, strongly impairs transformation efficiency, suggesting that this periplasmic domain of ComEC could indeed serve a catalytic function as nuclease. By tracking fluorescently labeled DNA, we show that taken up DNA has a similar mobility as a protein, in spite of being a large polymer. DNA dynamics are similar within the periplasm as those of ComEA, suggesting that most taken up molecules are bound to ComEA. We show that DNA can be highly mobile within the periplasm, indicating that this subcellular space can act as reservoir for taken up DNA, before its entry into the cytosol. Importance Bacteria can take up DNA from the environment and incorporate it into their chromosome, termed "natural competence" that can result in the uptake of novel genetic information. We show that fluorescently labelled DNA moves within the periplasm of competent Bacillus subtilis cells, with similar dynamics as DNA receptor ComEA. This indicates that DNA can accumulate in the periplasm, likely bound by ComEA, and thus can be stored before uptake at the cell pole, via integral membrane DNA permease ComEC. Assembly of the latter assembles at the cell pole likely occurs by a diffusion-capture mechanism. DNA uptake into cells thus takes a detour through the entire periplasm, and involves a high degree of free diffusion along and within the cell membrane.
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31
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Leroux M, Soubry N, Reyes-Lamothe R. Dynamics of Proteins and Macromolecular Machines in Escherichia coli. EcoSal Plus 2021; 9:eESP00112020. [PMID: 34060908 PMCID: PMC11163846 DOI: 10.1128/ecosalplus.esp-0011-2020] [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: 01/25/2021] [Accepted: 03/16/2021] [Indexed: 11/20/2022]
Abstract
Proteins are major contributors to the composition and the functions in the cell. They often assemble into larger structures, macromolecular machines, to carry out intricate essential functions. Although huge progress in understanding how macromolecular machines function has been made by reconstituting them in vitro, the role of the intracellular environment is still emerging. The development of fluorescence microscopy techniques in the last 2 decades has allowed us to obtain an increased understanding of proteins and macromolecular machines in cells. Here, we describe how proteins move by diffusion, how they search for their targets, and how they are affected by the intracellular environment. We also describe how proteins assemble into macromolecular machines and provide examples of how frequent subunit turnover is used for them to function and to respond to changes in the intracellular conditions. This review emphasizes the constant movement of molecules in cells, the stochastic nature of reactions, and the dynamic nature of macromolecular machines.
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Affiliation(s)
- Maxime Leroux
- Department of Biology, McGill University, Montreal, QC, Canada
| | - Nicolas Soubry
- Department of Biology, McGill University, Montreal, QC, Canada
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32
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Lisitsa AE, Sukovatyi LA, Bartsev SI, Deeva AA, Kratasyuk VA, Nemtseva EV. Mechanisms of Viscous Media Effects on Elementary Steps of Bacterial Bioluminescent Reaction. Int J Mol Sci 2021; 22:8827. [PMID: 34445534 PMCID: PMC8396235 DOI: 10.3390/ijms22168827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/06/2021] [Accepted: 08/10/2021] [Indexed: 12/16/2022] Open
Abstract
Enzymes activity in a cell is determined by many factors, among which viscosity of the microenvironment plays a significant role. Various cosolvents can imitate intracellular conditions in vitro, allowing to reduce a combination of different regulatory effects. The aim of the study was to analyze the media viscosity effects on the rate constants of the separate stages of the bacterial bioluminescent reaction. Non-steady-state reaction kinetics in glycerol and sucrose solutions was measured by stopped-flow technique and analyzed with a mathematical model developed in accordance with the sequence of reaction stages. Molecular dynamics methods were applied to reveal the effects of cosolvents on luciferase structure. We observed both in glycerol and in sucrose media that the stages of luciferase binding with flavin and aldehyde, in contrast to oxygen, are diffusion-limited. Moreover, unlike glycerol, sucrose solutions enhanced the rate of an electronically excited intermediate formation. The MD simulations showed that, in comparison with sucrose, glycerol molecules could penetrate the active-site gorge, but sucrose solutions caused a conformational change of functionally important αGlu175 of luciferase. Therefore, both cosolvents induce diffusion limitation of substrates binding. However, in sucrose media, increasing enzyme catalytic constant neutralizes viscosity effects. The activating effect of sucrose can be attributed to its exclusion from the catalytic gorge of luciferase and promotion of the formation of the active site structure favorable for the catalysis.
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Affiliation(s)
- Albert E Lisitsa
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
| | - Lev A Sukovatyi
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
| | - Sergey I Bartsev
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
- The Institute of Biophysics SB RAS, Akademgorodok 50/50, 660036 Krasnoyarsk, Russia
| | - Anna A Deeva
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
| | - Valentina A Kratasyuk
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
- The Institute of Biophysics SB RAS, Akademgorodok 50/50, 660036 Krasnoyarsk, Russia
| | - Elena V Nemtseva
- Biophysics Department, Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk, Russia
- The Institute of Biophysics SB RAS, Akademgorodok 50/50, 660036 Krasnoyarsk, Russia
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33
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Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
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Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
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Kirschbaum J, Zwicker D. Controlling biomolecular condensates via chemical reactions. J R Soc Interface 2021; 18:20210255. [PMID: 34186016 PMCID: PMC8241490 DOI: 10.1098/rsif.2021.0255] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022] Open
Abstract
Biomolecular condensates are small droplets forming spontaneously in biological cells through phase separation. They play a role in many cellular processes, but it is unclear how cells control them. Cellular regulation often relies on post-translational modifications of proteins. For biomolecular condensates, such chemical modifications could alter the molecular interaction of key condensate components. Here, we test this idea using a theoretical model based on non-equilibrium thermodynamics. In particular, we describe the chemical reactions using transition-state theory, which accounts for the non-ideality of phase separation. We identify that fast control, as in cell signalling, is only possible when external energy input drives the reaction out of equilibrium. If this reaction differs inside and outside the droplet, it is even possible to control droplet sizes. Such an imbalance in the reaction could be created by enzymes localizing to the droplet. Since this situation is typical inside cells, we speculate that our proposed mechanism is used to stabilize multiple droplets with independently controlled size and count. Our model provides a novel and thermodynamically consistent framework for describing droplets subject to non-equilibrium chemical reactions.
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Affiliation(s)
- Jan Kirschbaum
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
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35
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Alvarez-Sieiro P, Sikkema HR, Poolman B. Heterodimer Formation of the Homodimeric ABC Transporter OpuA. Int J Mol Sci 2021; 22:ijms22115912. [PMID: 34072847 PMCID: PMC8199443 DOI: 10.3390/ijms22115912] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
Many proteins have a multimeric structure and are composed of two or more identical subunits. While this can be advantageous for the host organism, it can be a challenge when targeting specific residues in biochemical analyses. In vitro splitting and re-dimerization to circumvent this problem is a tedious process that requires stable proteins. We present an in vivo approach to transform homodimeric proteins into apparent heterodimers, which then can be purified using two-step affinity-tag purification. This opens the door to both practical applications such as smFRET to probe the conformational dynamics of homooligomeric proteins and fundamental research into the mechanism of protein multimerization, which is largely unexplored for membrane proteins. We show that expression conditions are key for the formation of heterodimers and that the order of the differential purification and reconstitution of the protein into nanodiscs is important for a functional ABC-transporter complex.
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36
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Iyer A, Baranov M, Foster AJ, Chordia S, Roelfes G, Vlijm R, van den Bogaart G, Poolman B. Chemogenetic Tags with Probe Exchange for Live-Cell Fluorescence Microscopy. ACS Chem Biol 2021; 16:891-904. [PMID: 33913682 PMCID: PMC8154248 DOI: 10.1021/acschembio.1c00100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022]
Abstract
Fluorogenic protein tagging systems have been less developed for prokaryotes than for eukaryotic cell systems. Here, we extend the concept of noncovalent fluorogenic protein tags in bacteria by introducing transcription factor-based tags, namely, LmrR and RamR, for probe binding and fluorescence readout under aerobic and anaerobic conditions. We developed two chemogenetic protein tags that impart fluorogenicity and a longer fluorescence lifetime to reversibly bound organic fluorophores, hence the name Chemogenetic Tags with Probe Exchange (CTPEs). We present an extensive characterization of 30 fluorophores reversibly interacting with the two different CTPEs and conclude that aromatic planar structures bind with high specificity to the hydrophobic pockets of these tags. The reversible binding of organic fluorophores to the CTPEs and the superior photophysical properties of organic fluorophores enable long-term fluorescence microscopy of living bacterial cells. Our protein tags provide a general tool for investigating (sub)cellular protein localization and dynamics, protein-protein interactions, and prolonged live-cell microscopy, even under oxygen-free conditions.
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Affiliation(s)
- Aditya Iyer
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Maxim Baranov
- Department
of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Alexander J. Foster
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Shreyans Chordia
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gerard Roelfes
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Rifka Vlijm
- Molecular
Biophysics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Geert van den Bogaart
- Department
of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Bert Poolman
- Department
of Biochemistry, Groningen Biomolecular Sciences and Biotechnology
Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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37
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Kim D, Rahhal N, Rademacher C. Elucidating Carbohydrate-Protein Interactions Using Nanoparticle-Based Approaches. Front Chem 2021; 9:669969. [PMID: 34046397 PMCID: PMC8144316 DOI: 10.3389/fchem.2021.669969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/06/2021] [Indexed: 12/12/2022] Open
Abstract
Carbohydrates are present on every living cell and coordinate important processes such as self/non-self discrimination. They are amongst the first molecular determinants to be encountered when cellular interactions are initiated. In particular, they resemble essential molecular fingerprints such as pathogen-, danger-, and self-associated molecular patterns guiding key decision-making in cellular immunology. Therefore, a deeper understanding of how cellular receptors of the immune system recognize incoming particles, based on their carbohydrate signature and how this information is translated into a biological response, will enable us to surgically manipulate them and holds promise for novel therapies. One approach to elucidate these early recognition events of carbohydrate interactions at cellular surfaces is the use of nanoparticles coated with defined carbohydrate structures. These particles are captured by carbohydrate receptors and initiate a cellular cytokine response. In the case of endocytic receptors, the capturing enables the engulfment of exogenous particles. Thereafter, the particles are sorted and degraded during their passage in the endolysosomal pathway. Overall, these processes are dependent on the nature of the endocytic carbohydrate receptors and consequently reflect upon the carbohydrate patterns on the exogenous particle surface. This interplay is still an under-studied subject. In this review, we summarize the application of nanoparticles as a promising tool to monitor complex carbohydrate-protein interactions in a cellular context and their application in areas of biomedicine.
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Affiliation(s)
- Dongyoon Kim
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Nowras Rahhal
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Max F. Perutz Laboratories, Department of Microbiology and Immunobiology, Vienna, Austria
| | - Christoph Rademacher
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
- Max F. Perutz Laboratories, Department of Microbiology and Immunobiology, Vienna, Austria
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38
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Labourel F, Rajon E. Resource uptake and the evolution of moderately efficient enzymes. Mol Biol Evol 2021; 38:3938-3952. [PMID: 33964160 PMCID: PMC8382906 DOI: 10.1093/molbev/msab132] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Enzymes speed up reactions that would otherwise be too slow to sustain the metabolism of selfreplicators. Yet, most enzymes seem only moderately efficient, exhibiting kinetic parameters orders of magnitude lower than their expected physically achievable maxima and spanning over surprisingly large ranges of values. Here, we question how these parameters evolve using a mechanistic model where enzyme efficiency is a key component of individual competition for resources. We show that kinetic parameters are under strong directional selection only up to a point, above which enzymes appear to evolve under near-neutrality, thereby confirming the qualitative observation of other modeling approaches. While the existence of a large fitness plateau could potentially explain the extensive variation in enzyme features reported, we show using a population genetics model that such a widespread distribution is an unlikely outcome of evolution on a common landscape, as mutation–selection–drift balance occupy a narrow area even when very moderate biases towards lower efficiency are considered. Instead, differences in the evolutionary context encountered by each enzyme should be involved, such that each evolves on an individual, unique landscape. Our results point to drift and effective population size playing an important role, along with the kinetics of nutrient transporters, the tolerance to high concentrations of intermediate metabolites, and the reversibility of reactions. Enzyme concentration also shapes selection on kinetic parameters, but we show that the joint evolution of concentration and efficiency does not yield extensive variance in evolutionary outcomes when documented costs to protein expression are applied.
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Affiliation(s)
- Florian Labourel
- Univ Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR5558, Villeurbanne, F-69622, France
| | - Etienne Rajon
- Univ Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR5558, Villeurbanne, F-69622, France
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39
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Grant NA, Abdel Magid A, Franklin J, Dufour Y, Lenski RE. Changes in Cell Size and Shape during 50,000 Generations of Experimental Evolution with Escherichia coli. J Bacteriol 2021; 203:e00469-20. [PMID: 33649147 PMCID: PMC8088598 DOI: 10.1128/jb.00469-20] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 02/18/2021] [Indexed: 02/07/2023] Open
Abstract
Bacteria adopt a wide variety of sizes and shapes, with many species exhibiting stereotypical morphologies. How morphology changes, and over what timescales, is less clear. Previous work examining cell morphology in an experiment with Escherichia coli showed that populations evolved larger cells and, in some cases, cells that were less rod-like. That experiment has now run for over two more decades. Meanwhile, genome sequence data are available for these populations, and new computational methods enable high-throughput microscopic analyses. In this study, we measured stationary-phase cell volumes for the ancestor and 12 populations at 2,000, 10,000, and 50,000 generations, including measurements during exponential growth at the last time point. We measured the distribution of cell volumes for each sample using a Coulter counter and microscopy, the latter of which also provided data on cell shape. Our data confirm the trend toward larger cells while also revealing substantial variation in size and shape across replicate populations. Most populations first evolved wider cells but later reverted to the ancestral length-to-width ratio. All but one population evolved mutations in rod shape maintenance genes. We also observed many ghost-like cells in the only population that evolved the novel ability to grow on citrate, supporting the hypothesis that this lineage struggles with maintaining balanced growth. Lastly, we show that cell size and fitness remain correlated across 50,000 generations. Our results suggest that larger cells are beneficial in the experimental environment, while the reversion toward ancestral length-to-width ratios suggests partial compensation for the less favorable surface area-to-volume ratios of the evolved cells.IMPORTANCE Bacteria exhibit great morphological diversity, yet we have only a limited understanding of how their cell sizes and shapes evolve and of how these features affect organismal fitness. This knowledge gap reflects, in part, the paucity of the fossil record for bacteria. In this study, we revived and analyzed samples extending over 50,000 generations from 12 populations of experimentally evolving Escherichia coli to investigate the relation between cell size, shape, and fitness. Using this "frozen fossil record," we show that all 12 populations evolved larger cells concomitant with increased fitness, with substantial heterogeneity in cell size and shape across the replicate lines. Our work demonstrates that cell morphology can readily evolve and diversify, even among populations living in identical environments.
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Affiliation(s)
- Nkrumah A Grant
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, USA
| | - Ali Abdel Magid
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Joshua Franklin
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Yann Dufour
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
- Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, USA
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40
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Line-FRAP, A Versatile Method to Measure Diffusion Rates In Vitro and In Vivo. J Mol Biol 2021; 433:166898. [PMID: 33647289 DOI: 10.1016/j.jmb.2021.166898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 12/12/2022]
Abstract
The crowded cellular milieu affect molecular diffusion through hard (occluded space) and soft (weak, non-specific) interactions. Multiple methods have been developed to measure diffusion coefficients at physiological protein concentrations within cells, each with its limitations. Here, we show that Line-FRAP, combined with rigours data analysis, is able to determine diffusion coefficients in a variety of environments, from in vitro to in vivo. The use of Line mode greatly improves time resolution of FRAP data acquisition, from 20-100 Hz in the classical mode to 800 Hz in the line mode. This improves data analysis, as intensity and radius of the bleach at the first post-bleach frame is critical. We evaluated the method on different proteins labelled chemically or fused to YFP in a wide range of environments. The diffusion coefficients measured in HeLa and in E. coli were ~2.5-fold and 15-fold slower than in buffer, and were comparable to previously published data. Increasing the osmotic pressure on E. coli further decreases diffusion, to the point at which proteins virtually stop moving. The method presented here, which requires a confocal microscope equipped with dual scanners, can be applied to study a large range of molecules with different sizes, and provides robust results in a wide range of environments and protein concentrations for fast diffusing molecules.
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41
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Stracy M, Schweizer J, Sherratt DJ, Kapanidis AN, Uphoff S, Lesterlin C. Transient non-specific DNA binding dominates the target search of bacterial DNA-binding proteins. Mol Cell 2021; 81:1499-1514.e6. [PMID: 33621478 PMCID: PMC8022225 DOI: 10.1016/j.molcel.2021.01.039] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/24/2020] [Accepted: 01/27/2021] [Indexed: 12/18/2022]
Abstract
Despite their diverse biochemical characteristics and functions, all DNA-binding proteins share the ability to accurately locate their target sites among the vast excess of non-target DNA. Toward identifying universal mechanisms of the target search, we used single-molecule tracking of 11 diverse DNA-binding proteins in living Escherichia coli. The mobility of these proteins during the target search was dictated by DNA interactions rather than by their molecular weights. By generating cells devoid of all chromosomal DNA, we discovered that the nucleoid is not a physical barrier for protein diffusion but significantly slows the motion of DNA-binding proteins through frequent short-lived DNA interactions. The representative DNA-binding proteins (irrespective of their size, concentration, or function) spend the majority (58%–99%) of their search time bound to DNA and occupy as much as ∼30% of the chromosomal DNA at any time. Chromosome crowding likely has important implications for the function of all DNA-binding proteins. Protein motion was compared between unperturbed cells and DNA-free cells Protein mobility was dictated by DNA interactions rather than molecular weight The nucleoid is not a physical barrier for protein diffusion The proteins studied spend most (58%–99%) of their search time bound to DNA
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Affiliation(s)
- Mathew Stracy
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Jakob Schweizer
- Max Planck Institute for Dynamics of Complex Technical Systems, 39106 Magdeburg, Germany
| | - David J Sherratt
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Achillefs N Kapanidis
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, UK
| | - Stephan Uphoff
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Christian Lesterlin
- Molecular Microbiology and Structural Biochemistry (MMSB), Université Lyon 1, CNRS, INSERM, UMR5086, 69007 Lyon, France.
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42
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Roosen-Runge F, Schurtenberger P, Stradner A. Self-diffusion of nonspherical particles fundamentally conflicts with effective sphere models. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:154002. [PMID: 33498038 DOI: 10.1088/1361-648x/abdff9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Modeling diffusion of nonspherical particles presents an unsolved and considerable challenge, despite its importance for the understanding of crowding effects in biology, food technology and formulation science. A common approach in experiment and simulation is to map nonspherical objects on effective spheres to subsequently use the established predictions for spheres to approximate phenomena for nonspherical particles. Using numerical evaluation of the hydrodynamic mobility tensor, we show that this so-called effective sphere model fundamentally fails to represent the self-diffusion in solutions of ellipsoids as well as rod-like assemblies of spherical beads. The effective sphere model drastically overestimates the slowing down of self-diffusion down to volume fractions below 0.01. Furthermore, even the linear term relevant at lower volume fraction is inaccurate, linked to a fundamental misconception of effective sphere models. To overcome the severe problems related with the use of effective sphere models, we suggest a protocol to predict the short-time self-diffusion of rod-like systems, based on simulations with hydrodynamic interactions that become feasible even for more complex molecules as the essential observable shows a negligible system-size effect.
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Affiliation(s)
- Felix Roosen-Runge
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
- Department of Biomedical Sciences and Biofilms-Research Center for Biointerfaces (BRCB), Faculty of Health and Society, Malmö University, Sweden
| | - Peter Schurtenberger
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
| | - Anna Stradner
- Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden
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43
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Tran BM, Prabha H, Iyer A, O'Byrne C, Abee T, Poolman B. Measurement of Protein Mobility in Listeria monocytogenes Reveals a Unique Tolerance to Osmotic Stress and Temperature Dependence of Diffusion. Front Microbiol 2021; 12:640149. [PMID: 33679676 PMCID: PMC7925416 DOI: 10.3389/fmicb.2021.640149] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/21/2021] [Indexed: 11/18/2022] Open
Abstract
Protein mobility in the cytoplasm is essential for cellular functions, and slow diffusion may limit the rates of biochemical reactions in the living cell. Here, we determined the apparent lateral diffusion coefficient (DL) of GFP in Listeria monocytogenes as a function of osmotic stress, temperature, and media composition. We find that DL is much less affected by hyperosmotic stress in L. monocytogenes than under similar conditions in Lactococcus lactis and Escherichia coli. We find a temperature optimum for protein diffusion in L. monocytogenes at 30°C, which deviates from predicted trends from the generalized Stokes-Einstein equation under dilute conditions and suggests that the structure of the cytoplasm and macromolecular crowding vary as a function of temperature. The turgor pressure of L. monocytogenes is comparable to other Gram-positive bacteria like Bacillus subtilis and L. lactis but higher in a knockout strain lacking the stress-inducible sigma factor SigB. We discuss these findings in the context of how L. monocytogenes survives during environmental transmission and interaction with the human host.
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Affiliation(s)
- Buu Minh Tran
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Haritha Prabha
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Aditya Iyer
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
| | - Conor O'Byrne
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Tjakko Abee
- Laboratory of Food Microbiology, Wageningen University Research, Wageningen, Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Groningen, Netherlands
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44
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Clark BC, Kolb VM. Macrobiont: Cradle for the Origin of Life and Creation of a Biosphere. Life (Basel) 2020; 10:life10110278. [PMID: 33198206 PMCID: PMC7697624 DOI: 10.3390/life10110278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023] Open
Abstract
Although the cellular microorganism is the fundamental unit of biology, the origin of life (OoL) itself is unlikely to have occurred in a microscale environment. The macrobiont (MB) is the macro-scale setting where life originated. Guided by the methodologies of Systems Analysis, we focus on subaerial ponds of scale 3 to 300 m diameter. Within such ponds, there can be substantial heterogeneity, on the vertical, horizontal, and temporal scales, which enable multi-pot prebiotic chemical evolution. Pond size-sensitivities for several figures of merit are mathematically formulated, leading to the expectation that the optimum pond size for the OoL is intermediate, but biased toward smaller sizes. Sensitivities include relative access to nutrients, energy sources, and catalysts, as sourced from geological, atmospheric, hydrospheric, and astronomical contributors. Foreshores, especially with mudcracks, are identified as a favorable component for the success of the macrobiont. To bridge the gap between inanimate matter and a planetary-scale biosphere, five stages of evolution within the macrobiont are hypothesized: prebiotic chemistry → molecular replicator → protocell → macrobiont cell → colonizer cell. Comparison of ponds with other macrobionts, including hydrothermal and meteorite settings, allows a conclusion that more than one possible macrobiont locale could enable an OoL.
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Affiliation(s)
- Benton C. Clark
- Space Science Institute, Boulder, CO 80301, USA
- Correspondence:
| | - Vera M. Kolb
- Department of Chemistry, University of Wisconsin—Parkside, Kenosha, WI 53141, USA;
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45
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Yang B, Kwon K, Jana S, Kim S, Avila-Crump S, Tae G, Mehl RA, Kwon I. Temporal Control of Efficient In Vivo Bioconjugation Using a Genetically Encoded Tetrazine-Mediated Inverse-Electron-Demand Diels–Alder Reaction. Bioconjug Chem 2020; 31:2456-2464. [DOI: 10.1021/acs.bioconjchem.0c00497] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Byungseop Yang
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Kiyoon Kwon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Subhashis Jana
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Seoungkyun Kim
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Savanna Avila-Crump
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Giyoong Tae
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Ryan A. Mehl
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Inchan Kwon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
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46
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Skóra T, Vaghefikia F, Fitter J, Kondrat S. Macromolecular Crowding: How Shape and Interactions Affect Diffusion. J Phys Chem B 2020; 124:7537-7543. [PMID: 32790396 DOI: 10.1021/acs.jpcb.0c04846] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A significant fraction of the cell volume is occupied by various proteins, polysaccharides, nucleic acids, etc., which considerably reduces the mobility of macromolecules. Theoretical and experimental work so far have mainly focused on the dependence of the mobility on the occupied volume, while the effect of a macromolecular shape received less attention. Herein, using fluorescence correlation spectroscopy (FCS) and Brownian dynamics (BD) simulations, we report on a dramatic slowdown of tracer diffusion by cylindrically shaped double-stranded (ds) DNAs (16 nm in length). We find, for instance, that the translational diffusion coefficient of a streptavidin tracer is reduced by about 60% for a volume fraction of dsDNA as low as just 5%. For comparison, for a spherical crowder (Ficoll70) the slowdown is only 10% at the same volume fraction and 60% reduction occurs at a volume fraction as high as 35%. BD simulations reveal that this reduction can be attributed to a larger volume excluded to a tracer by dsDNA particles, as compared with spherical Ficoll70 at the same volume fraction, and to the differences in the tracer-crowder attractive interactions. In addition, we find using BD simulations that rotational diffusion of dsDNA is less affected by the crowder shape than its translational motion. Our results show that diffusion in crowded systems is determined not merely by the occupied volume fraction, but that the shape and interactions can determine diffusion, which is relevant to the diverse intracellular environments inside living cells.
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Affiliation(s)
- Tomasz Skóra
- Department of Complex Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Farzaneh Vaghefikia
- I. Physikalisches Institut (IA), AG Biophysik, RWTH Aachen University, 52074 Aachen, Germany
| | - Jörg Fitter
- I. Physikalisches Institut (IA), AG Biophysik, RWTH Aachen University, 52074 Aachen, Germany.,Institut für Biologische Informationsprozesse (IBI-6), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Svyatoslav Kondrat
- Department of Complex Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.,Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany.,Institut für Theoretische Physik IV, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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Kohyama S, Fujiwara K, Yoshinaga N, Doi N. Conformational equilibrium of MinE regulates the allowable concentration ranges of a protein wave for cell division. NANOSCALE 2020; 12:11960-11970. [PMID: 32458918 DOI: 10.1039/d0nr00242a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The Min system for determining the cell division position at the center in bacteria has a unique character that uses a protein wave (Min wave) that emerges from its components (MinD and MinE). The Min wave emerges under the coupling of chemical reactions and molecular diffusions of MinDE and appears when the concentrations of MinD and MinE are similar. However, the nanoscale mechanism to determine their concentration ranges has remained elusive. In this study, by using artificial cells as a mimic of cells, we showed that the dominant MinE conformations determined the allowable concentration ranges for the emergence of the Min wave. Furthermore, the deletion of the membrane-binding region of MinE indicated that the region was essential for limiting the concentration ranges to be narrower. These findings illustrate a parameter tuning mechanism underlying complex molecular systems at the nanoscale for spatiotemporal regulation in living cells and show a possibility that the regulation of the equilibrium among molecular conformations can work as a switch for cell division.
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Affiliation(s)
- Shunshi Kohyama
- Department of Biosciences & Informatics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Kei Fujiwara
- Department of Biosciences & Informatics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Natsuhiko Yoshinaga
- Mathematical Science Group, WPI Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Katahira 2-1-1, Aoba-Ku, Sendai 9808577, Japan and MathAM-OIL, AIST, Sendai 980-8577, Japan
| | - Nobuhide Doi
- Department of Biosciences & Informatics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
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Metal-induced sensor mobilization turns on affinity to activate regulator for metal detoxification in live bacteria. Proc Natl Acad Sci U S A 2020; 117:13248-13255. [PMID: 32467170 DOI: 10.1073/pnas.1919816117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Metal detoxification is essential for bacteria's survival in adverse environments and their pathogenesis in hosts. Understanding the underlying mechanisms is crucial for devising antibacterial treatments. In the Gram-negative bacterium Escherichia coli, membrane-bound sensor CusS and its response regulator CusR together regulate the transcription of the cus operon that plays important roles in cells' resistance to copper/silver, and they belong to the two-component systems (TCSs) that are ubiquitous across various organisms and regulate diverse cellular functions. In vitro protein reconstitution and associated biochemical/physical studies have provided significant insights into the functions and mechanisms of CusS-CusR and related TCSs. Such studies are challenging regarding multidomain membrane proteins like CusS and also lack the physiological environment, particularly the native spatial context of proteins inside a cell. Here, we use stroboscopic single-molecule imaging and tracking to probe the dynamic behaviors of both CusS and CusR in live cells, in combination with protein- or residue-specific genetic manipulations. We find that copper stress leads to a cellular protein concentration increase and a concurrent mobilization of CusS out of clustered states in the membrane. We show that the mobilized CusS has significant interactions with CusR for signal transduction and that CusS's affinity toward CusR switches on upon sensing copper at the interfacial metal-binding sites in CusS's periplasmic sensor domains, prior to ATP binding and autophosphorylation at CusS's cytoplasmic kinase domain(s). The observed CusS mobilization upon stimulation and its surprisingly early interaction with CusR likely ensure an efficient signal transduction by providing proper conformation and avoiding futile cross talks.
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Abstract
The notion that graded distributions of signals underlie the spatial organization of biological systems has long been a central pillar in the fields of cell and developmental biology. During morphogenesis, morphogens spread across tissues to guide development of the embryo. Similarly, a variety of dynamic gradients and pattern-forming networks have been discovered that shape subcellular organization. Here we discuss the principles of intracellular pattern formation by these intracellular morphogens and relate them to conceptually similar processes operating at the tissue scale. We will specifically review mechanisms for generating cellular asymmetry and consider how intracellular patterning networks are controlled and adapt to cellular geometry. Finally, we assess the general concept of intracellular gradients as a mechanism for positional control in light of current data, highlighting how the simple readout of fixed concentration thresholds fails to fully capture the complexity of spatial patterning processes occurring inside cells.
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Affiliation(s)
- Lars Hubatsch
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Nathan W Goehring
- The Francis Crick Institute, London, United Kingdom; Institute for the Physics of Living Systems, University College London, London, United Kingdom; MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom.
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50
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Kim TK, Lee BW, Fujii F, Lee KH, Lee S, Park Y, Kim JK, Lee SW, Pack CG. Mitotic Chromosomes in Live Cells Characterized Using High-Speed and Label-Free Optical Diffraction Tomography. Cells 2019; 8:cells8111368. [PMID: 31683735 PMCID: PMC6912651 DOI: 10.3390/cells8111368] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 12/16/2022] Open
Abstract
The cell nucleus is a three-dimensional, dynamic organelle organized into subnuclear compartments such as chromatin and nucleoli. The structure and function of these compartments are maintained by diffusion and interactions between related factors as well as by dynamic and structural changes. Recent studies using fluorescent microscopic techniques suggest that protein factors can access and are freely mobile in heterochromatin and in mitotic chromosomes, despite their densely packed structure. However, the physicochemical properties of the chromosome during cell division are not fully understood. In the present study, characteristic properties such as the refractive index (RI), volume of the mitotic chromosomes, and diffusion coefficient (D) of fluorescent probes inside the chromosome were quantified using an approach combining label-free optical diffraction tomography with complementary confocal laser-scanning microscopy and fluorescence correlation spectroscopy. Variations in these parameters correlated with osmotic conditions, suggesting that changes in RI are consistent with those of the diffusion coefficient for mitotic chromosomes and cytosol. Serial RI tomography images of chromosomes in live cells during mitosis were compared with three-dimensional confocal micrographs to demonstrate that compaction and decompaction of chromosomes induced by osmotic change were characterized by linked changes in chromosome RI, volume, and the mobilities of fluorescent proteins.
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Affiliation(s)
- Tae-Keun Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - Byong-Wook Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - Fumihiko Fujii
- Division of Physical Pharmacy, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, Japan.
| | | | - Sanghwa Lee
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
| | - YongKeun Park
- Tomocube Inc., Daejeon 34051, Korea.
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
| | - Jun Ki Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
| | - Sang-Wook Lee
- Department of Radiation Oncology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
| | - Chan-Gi Pack
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea.
- Department of Convergence Medicine, University of Ulsan College of Medicine, Seoul 05505, Korea.
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