1
|
Losa J, Heinemann M. Contribution of different macromolecules to the diffusion of a 40 nm particle in Escherichia coli. Biophys J 2024; 123:1211-1221. [PMID: 38555507 PMCID: PMC11140462 DOI: 10.1016/j.bpj.2024.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/20/2024] [Accepted: 03/28/2024] [Indexed: 04/02/2024] Open
Abstract
Due to the high concentration of proteins, nucleic acids, and other macromolecules, the bacterial cytoplasm is typically described as a crowded environment. However, the extent to which each of these macromolecules individually affects the mobility of macromolecular complexes, and how this depends on growth conditions, is presently unclear. In this study, we sought to quantify the crowding experienced by an exogenous 40 nm fluorescent particle in the cytoplasm of E. coli under different growth conditions. By performing single-particle tracking measurements in cells selectively depleted of DNA and/or mRNA, we determined the contribution to crowding of mRNA, DNA, and remaining cellular components, i.e., mostly proteins and ribosomes. To estimate this contribution to crowding, we quantified the difference of the particle's diffusion coefficient in conditions with and without those macromolecules. We found that the contributions of the three classes of components were of comparable magnitude, being largest in the case of proteins and ribosomes. We further found that the contributions of mRNA and DNA to crowding were significantly larger than expected based on their volumetric fractions alone. Finally, we found that the crowding contributions change only slightly with the growth conditions. These results reveal how various cellular components partake in crowding of the cytoplasm and the consequences this has for the mobility of large macromolecular complexes.
Collapse
Affiliation(s)
- José Losa
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Matthias Heinemann
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, the Netherlands.
| |
Collapse
|
2
|
Mukherjee P, Mazumder A. Macromolecular crowding has opposite effects on two critical sub-steps of transcription initiation. FEBS Lett 2024; 598:1022-1033. [PMID: 38479985 PMCID: PMC7615953 DOI: 10.1002/1873-3468.14851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/12/2024] [Accepted: 02/19/2024] [Indexed: 04/12/2024]
Abstract
Transcription initiation, the first step in gene expression, has been studied extensively in dilute buffer, a condition which fails to consider the crowded environment in live cells. Recent reports indicate the kinetics of promoter escape is altered in crowded conditions for a consensus bacterial promoter. Here, we use a real-time fluorescence enhancement assay to study the kinetics of unwound bubble formation and promoter escape for three separate promoters. We find that the effect of crowding on transcription initiation is complex, with lower rates of unwound bubble formation, higher rates of promoter escape, and large variations depending on promoter identity. Based on our results, we suggest that altered conditions of crowding inside a live cell can trigger global changes.
Collapse
Affiliation(s)
- Pratip Mukherjee
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, Ghaziabad, India
| | - Abhishek Mazumder
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| |
Collapse
|
3
|
Collette D, Dunlap D, Finzi L. Macromolecular Crowding and DNA: Bridging the Gap between In Vitro and In Vivo. Int J Mol Sci 2023; 24:17502. [PMID: 38139331 PMCID: PMC10744201 DOI: 10.3390/ijms242417502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
The cellular environment is highly crowded, with up to 40% of the volume fraction of the cell occupied by various macromolecules. Most laboratory experiments take place in dilute buffer solutions; by adding various synthetic or organic macromolecules, researchers have begun to bridge the gap between in vitro and in vivo measurements. This is a review of the reported effects of macromolecular crowding on the compaction and extension of DNA, the effect of macromolecular crowding on DNA kinetics, and protein-DNA interactions. Theoretical models related to macromolecular crowding and DNA are briefly reviewed. Gaps in the literature, including the use of biologically relevant crowders, simultaneous use of multi-sized crowders, empirical connections between macromolecular crowding and liquid-liquid phase separation of nucleic materials are discussed.
Collapse
Affiliation(s)
| | | | - Laura Finzi
- Department of Physics, College of Arts & Sciences, Emory University, Atlanta, GA 30322, USA; (D.C.); (D.D.)
| |
Collapse
|
4
|
Joron K, Viegas JO, Haas-Neill L, Bier S, Drori P, Dvir S, Lim PSL, Rauscher S, Meshorer E, Lerner E. Fluorescent protein lifetimes report densities and phases of nuclear condensates during embryonic stem-cell differentiation. Nat Commun 2023; 14:4885. [PMID: 37573411 PMCID: PMC10423231 DOI: 10.1038/s41467-023-40647-6] [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: 01/19/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
Fluorescent proteins (FP) are frequently used for studying proteins inside cells. In advanced fluorescence microscopy, FPs can report on additional intracellular variables. One variable is the local density near FPs, which can be useful in studying densities within cellular bio-condensates. Here, we show that a reduction in fluorescence lifetimes of common monomeric FPs reports increased levels of local densities. We demonstrate the use of this fluorescence-based variable to report the distribution of local densities within heterochromatin protein 1α (HP1α) in mouse embryonic stem cells (ESCs), before and after early differentiation. We find that local densities within HP1α condensates in pluripotent ESCs are heterogeneous and cannot be explained by a single liquid phase. Early differentiation, however, induces a change towards a more homogeneous distribution of local densities, which can be explained as a liquid-like phase. In conclusion, we provide a fluorescence-based method to report increased local densities and apply it to distinguish between homogeneous and heterogeneous local densities within bio-condensates.
Collapse
Affiliation(s)
- Khalil Joron
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Juliane Oliveira Viegas
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Liam Haas-Neill
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Sariel Bier
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Shani Dvir
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Patrick Siang Lin Lim
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Sarah Rauscher
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel.
- Edmond and Lily Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
| |
Collapse
|
5
|
Xu S, Wang J, Dong J. Nonspecific interaction and overlap concentration influence macromolecular crowding effect on glucose oxidase activity. Int J Biol Macromol 2023; 241:124525. [PMID: 37086776 DOI: 10.1016/j.ijbiomac.2023.124525] [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: 01/21/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/24/2023]
Abstract
Macromolecular crowding can change kinetics of enzyme catalysis. How interaction between enzymes and neighboring macromolecules contributes to the crowding effect on enzyme catalysis has not been quantitatively revealed. In this study, crowding effects of dextran and poly(ethylene glycol) (PEG) on glucose oxidase (GOx) are studied. Fluorescence resonance energy transfer experiments show the high transfer efficiency and stable interaction between the dextran and GOx. Further fluorescence quenching analysis also proves that the association of the dextran-GOx pair can become stronger than that of the PEG-GOx pair. Dextrans with concentrations above or below their chain overlap concentrations (c*) reduce Michaelis constants (Km) of GOx catalysis by 90 % or 45 %, respectively, through volume exclusion mechanism, and in the meantime elevate the enzymatic efficiency (kcat/Km) by 8-fold or by 3-fold, respectively, which is more dramatic than that found in other enzymes before. Strong association between the enzyme and the dextran results in slow turnover rates (kcat). Intermediate crowding with weak to moderate affinity to the enzyme below the c* can tune the kcat higher than in the free state. Catalysis under crowded conditions is a joint effect of the enzyme-crowder nonspecific interaction, volume exclusion and overlap condition of the crowders.
Collapse
Affiliation(s)
- Siyuan Xu
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang Province 312000, China
| | - Jie Wang
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang Province 312000, China
| | - Jian Dong
- College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang Province 312000, China.
| |
Collapse
|
6
|
Chien PY, Gao L, Liu Y. Quantitative Analysis of Transcription Termination via Position-Selective Labeling of RNA (PLOR) Method. Int J Mol Sci 2023; 24:ijms24054934. [PMID: 36902367 PMCID: PMC10003555 DOI: 10.3390/ijms24054934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
T7 RNA polymerase is the most widely used enzyme in RNA synthesis, and it is also used for RNA labeling in position-selective labeling of RNA (PLOR). PLOR is a liquid-solid hybrid phase method that has been developed to introduce labels to specific positions of RNA. Here, we applied PLOR as a single-round transcription method to quantify the terminated and read-through products in transcription for the first time. Various factors, including pausing strategies, Mg2+, ligand and the NTP concentration at the transcriptional termination of adenine riboswitch RNA have been characterized. This helps to understand transcription termination, which is one of the least understood processes in transcription. Additionally, our strategy can potentially be used to study the co-transcription behavior of general RNA, especially when continuous transcription is not desired.
Collapse
|
7
|
Song E, Hwang S, Munasingha PR, Seo YS, Kang J, Kang C, Hohng S. Transcriptional pause extension benefits the stand-by rather than catch-up Rho-dependent termination. Nucleic Acids Res 2023; 51:2778-2789. [PMID: 36762473 PMCID: PMC10085680 DOI: 10.1093/nar/gkad051] [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: 09/05/2022] [Revised: 12/30/2022] [Accepted: 01/19/2023] [Indexed: 02/11/2023] Open
Abstract
Transcriptional pause is essential for all types of termination. In this single-molecule study on bacterial Rho factor-dependent terminators, we confirm that the three Rho-dependent termination routes operate compatibly together in a single terminator, and discover that their termination efficiencies depend on the terminational pauses in unexpected ways. Evidently, the most abundant route is that Rho binds nascent RNA first and catches up with paused RNA polymerase (RNAP) and this catch-up Rho mediates simultaneous releases of transcript RNA and template DNA from RNAP. The fastest route is that the catch-up Rho effects RNA-only release and leads to 1D recycling of RNAP on DNA. The slowest route is that the RNAP-prebound stand-by Rho facilitates only the simultaneous rather than sequential releases. Among the three routes, only the stand-by Rho's termination efficiency positively correlates with pause duration, contrary to a long-standing speculation, invariably in the absence or presence of NusA/NusG factors, competitor RNAs or a crowding agent. Accordingly, the essential terminational pause does not need to be long for the catch-up Rho's terminations, and long pauses benefit only the stand-by Rho's terminations. Furthermore, the Rho-dependent termination of mgtA and ribB riboswitches is controlled mainly by modulation of the stand-by rather than catch-up termination.
Collapse
Affiliation(s)
- Eunho Song
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Seungha Hwang
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Palinda Ruvan Munasingha
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Yeon-Soo Seo
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jin Young Kang
- Correspondence may also be addressed to Jin Young Kang. Tel: +82 42 350 2831;
| | - Changwon Kang
- Correspondence may also be addressed to Changwon Kang. Tel: +82 42 350 2610;
| | - Sungchul Hohng
- To whom correspondence should be addressed. Tel: +82 2 880 6593;
| |
Collapse
|
8
|
Simisi Clovis N, Alam P, Kumar Chand A, Sardana D, Firoz Khan M, Sen S. Molecular Crowders Modulate Ligand Binding Affinity to G-Quadruplex DNA by Decelerating Ligand Association. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
9
|
Yoo H, Davis CM. An in vitro cytomimetic of in-cell RNA folding. Chembiochem 2022; 23:e202200406. [PMID: 35999178 DOI: 10.1002/cbic.202200406] [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: 07/18/2022] [Revised: 08/21/2022] [Indexed: 11/07/2022]
Abstract
To discover the cytomimetic that accounts for cytoplasmic crowding and sticking on RNA stability, we conducted a two-dimensional scan of mixtures of artificial crowding and sticking agents, PEG10k and M-PERTM. As our model RNA, we investigate the fourU RNA thermometer motif of Salmonella, a hairpin-structured RNA that regulates translation by unfolding and exposing its RBS in response to temperature perturbations. We found that the addition of artificial crowding and sticking agents leads to a stabilization and destabilization of RNA folding, respectively, through the excluded volume effect and surface interactions. FRET-labels were added to the fourU RNA and Fast Relaxation Imaging (FReI), fluorescence microscopy coupled to temperature-jump spectroscopy, probed differences between folding stability of RNA inside single living cells and in vitro. Our results suggest that the cytoplasmic environment affecting RNA folding is comparable to a combination of 20% v/v M-PERTM and 150 g/L PEG10k.
Collapse
Affiliation(s)
- Hyejin Yoo
- Yale University, Chemistry, 225 Prospect St, 06511, New Haven, UNITED STATES
| | - Caitlin M Davis
- Yale University, Chemistry, 225 Prospect St., 06511, New Haven, UNITED STATES
| |
Collapse
|
10
|
Basu M, Mishra PP. Kineto-Mechanistic Investigation of Effect of Macromolecular Crowding on the Breathing of DNA Bubble. J Phys Chem B 2022; 126:1375-1387. [PMID: 35143192 DOI: 10.1021/acs.jpcb.1c08206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Macromolecular crowding along with hydrogen bonding or stacking interactions and hydration reportedly has enormous repercussions on elementary biochemical processes, such as the folding of proteins or nucleic acids involving the stability of DNA base pairing. By using the mismatch-induced DNA bubble as a mesoscopic model, the complex interplay of macromolecular crowding on the dynamical fluctuations at the bubble region within the thermodynamic limit has been monitored using single-molecule fluorescence resonance energy transfer (sm-FRET). These single-molecule experimental results have been further corroborated using physical models such as "scaled particle theory" (SPT) and "Gaussian cloud model" (GCM), to predict the biological activity of DNA. The two-state fluctuation of the DNA bubble has been visualized as a function of the nature, size, and concentration of the crowder. The influence of crowders on the DNA conformation has been investigated with the help of the m-factor, the eccentricity, and the kinetic and thermodynamic parameters without any prior assumption. The clear effect of crowding on the dynamics of such a simple biomolecular system emphasizes the power of single-molecule methods and the dependency of the radius of gyration of the co-solute as well as the preferential interaction with the crowder on the distinct conformational states adopted by the bubble. This study provides an idea and hypothesizes the preferential propensity of the DNA bubble to adopt a conformation with the single-stranded domains being far apart, independent of the crowder size, that may be beneficial for efficient recognition by proteins for an uninterrupted procession of the biological process of the central dogma.
Collapse
Affiliation(s)
- Manali Basu
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India.,Homi Bhaba National Institute, Mumbai, Maharashtra 400094, India
| | - Padmaja Prasad Mishra
- Single Molecule Biophysics Lab, Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India.,Homi Bhaba National Institute, Mumbai, Maharashtra 400094, India
| |
Collapse
|
11
|
Abstract
Rho is a hexameric bacterial RNA helicase, which became a paradigm of factor-dependent transcription termination. The broadly accepted ("textbook") model posits a series of steps, wherein Rho first binds C-rich Rho utilization (rut) sites on nascent RNA, uses its ATP-dependent translocase activity to catch up with RNA polymerase (RNAP), and either pulls the transcript from the elongation complex or pushes RNAP forward, thus terminating transcription. However, this appealingly simple mechano-chemical model lacks a biological realism and is increasingly at odds with genetic and biochemical data. Here, we summarize recent structural and biochemical studies that have advanced our understanding of molecular details of RNA recognition, termination signaling, and RNAP inactivation in Rho-dependent transcription termination, rebalancing the view in favor of an alternative "allosteric" mechanism. In the revised model, Rho binds RNAP early in elongation assisted by the cofactors NusA and NusG, forming a pre-termination complex (PTC). The formation of PTC allows Rho to continuously sample nascent transcripts for a termination signal, which subsequently traps the elongation complex in an inactive state prior to its dissociation.
Collapse
Affiliation(s)
- Zhitai Hao
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Vladimir Svetlov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Evgeny Nudler
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA.,Howard Hughes Medical Institute, New York University School of Medicine, New York, Ny, USA
| |
Collapse
|
12
|
Agarwal S, Klocke MA, Pungchai PE, Franco E. Dynamic self-assembly of compartmentalized DNA nanotubes. Nat Commun 2021; 12:3557. [PMID: 34117248 PMCID: PMC8196065 DOI: 10.1038/s41467-021-23850-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/20/2021] [Indexed: 02/05/2023] Open
Abstract
Bottom-up synthetic biology aims to engineer artificial cells capable of responsive behaviors by using a minimal set of molecular components. An important challenge toward this goal is the development of programmable biomaterials that can provide active spatial organization in cell-sized compartments. Here, we demonstrate the dynamic self-assembly of nucleic acid (NA) nanotubes inside water-in-oil droplets. We develop methods to encapsulate and assemble different types of DNA nanotubes from programmable DNA monomers, and demonstrate temporal control of assembly via designed pathways of RNA production and degradation. We examine the dynamic response of encapsulated nanotube assembly and disassembly with the support of statistical analysis of droplet images. Our study provides a toolkit of methods and components to build increasingly complex and functional NA materials to mimic life-like functions in synthetic cells.
Collapse
Affiliation(s)
- Siddharth Agarwal
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Melissa A Klocke
- Department of Mechanical Engineering, University of California, Riverside, CA, USA
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA, USA
| | - Passa E Pungchai
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Elisa Franco
- Department of Bioengineering, University of California, Los Angeles, CA, USA.
- Department of Mechanical Engineering, University of California, Riverside, CA, USA.
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA, USA.
- Molecular Biology Institute, University of California, Los Angeles, CA, USA.
| |
Collapse
|
13
|
Garnica-Galvez S, Korntner SH, Skoufos I, Tzora A, Diakakis N, Prassinos N, Zeugolis DI. Hyaluronic Acid as Macromolecular Crowder in Equine Adipose-Derived Stem Cell Cultures. Cells 2021; 10:859. [PMID: 33918830 PMCID: PMC8070604 DOI: 10.3390/cells10040859] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 01/10/2023] Open
Abstract
The use of macromolecular crowding in the development of extracellular matrix-rich cell-assembled tissue equivalents is continuously gaining pace in regenerative engineering. Despite the significant advancements in the field, the optimal macromolecular crowder still remains elusive. Herein, the physicochemical properties of different concentrations of different molecular weights hyaluronic acid (HA) and their influence on equine adipose-derived stem cell cultures were assessed. Within the different concentrations and molecular weight HAs, the 10 mg/mL 100 kDa and 500 kDa HAs exhibited the highest negative charge and hydrodynamic radius, and the 10 mg/mL 100 kDa HA exhibited the lowest polydispersity index and the highest % fraction volume occupancy. Although HA had the potential to act as a macromolecular crowding agent, it did not outperform carrageenan and Ficoll®, the most widely used macromolecular crowding molecules, in enhanced and accelerated collagen I, collagen III and collagen IV deposition.
Collapse
Affiliation(s)
- Sergio Garnica-Galvez
- Laboratory of Animal Science, Nutrition and Biotechnology, Department of Agriculture, University of Ioannina, 47100 Arta, Greece; (S.G.-G.); (I.S.); (A.T.)
- School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (N.D.); (N.P.)
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), H92 W2TY Galway, Ireland;
| | - Stefanie H. Korntner
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), H92 W2TY Galway, Ireland;
- Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), H92 W2TY Galway, Ireland
| | - Ioannis Skoufos
- Laboratory of Animal Science, Nutrition and Biotechnology, Department of Agriculture, University of Ioannina, 47100 Arta, Greece; (S.G.-G.); (I.S.); (A.T.)
| | - Athina Tzora
- Laboratory of Animal Science, Nutrition and Biotechnology, Department of Agriculture, University of Ioannina, 47100 Arta, Greece; (S.G.-G.); (I.S.); (A.T.)
| | - Nikolaos Diakakis
- School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (N.D.); (N.P.)
| | - Nikitas Prassinos
- School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece; (N.D.); (N.P.)
| | - Dimitrios I. Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), H92 W2TY Galway, Ireland;
- Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), H92 W2TY Galway, Ireland
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Faculty of Biomedical Sciences, Università della Svizzera Italiana (USI), 6904 Lugano, Switzerland
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), School of Mechanical and Materials Engineering, University College Dublin (UCD), D04 V1W8 Dublin, Ireland
| |
Collapse
|
14
|
Matsumoto S, Sugimoto N. New Insights into the Functions of Nucleic Acids Controlled by Cellular Microenvironments. Top Curr Chem (Cham) 2021; 379:17. [PMID: 33782792 DOI: 10.1007/s41061-021-00329-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/11/2021] [Indexed: 12/11/2022]
Abstract
The right-handed double-helical B-form structure (B-form duplex) has been widely recognized as the canonical structure of nucleic acids since it was first proposed by James Watson and Francis Crick in 1953. This B-form duplex model has a monochronic and static structure and codes genetic information within a sequence. Interestingly, DNA and RNA can form various non-canonical structures, such as hairpin loops, left-handed helices, triplexes, tetraplexes of G-quadruplex and i-motif, and branched junctions, in addition to the canonical structure. The formation of non-canonical structures depends not only on sequence but also on the surrounding environment. Importantly, these non-canonical structures may exhibit a wide variety of biological roles by changing their structures and stabilities in response to the surrounding environments, which undergo vast changes at specific locations and at specific times in cells. Here, we review recent progress regarding the interesting behaviors and functions of nucleic acids controlled by molecularly crowded cellular conditions. New insights gained from recent studies suggest that nucleic acids not only code genetic information in sequences but also have unknown functions regarding their structures and stabilities through drastic structural changes in cellular environments.
Collapse
Affiliation(s)
- Saki Matsumoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan. .,Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-Minamimachi, Kobe, 650-0047, Japan.
| |
Collapse
|
15
|
Shaban HA, Barth R, Bystricky K. Navigating the crowd: visualizing coordination between genome dynamics, structure, and transcription. Genome Biol 2020; 21:278. [PMID: 33203432 PMCID: PMC7670612 DOI: 10.1186/s13059-020-02185-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 10/19/2020] [Indexed: 12/12/2022] Open
Abstract
The eukaryotic genome is hierarchically structured yet highly dynamic. Regulating transcription in this environment demands a high level of coordination to permit many proteins to interact with chromatin fiber at appropriate sites in a timely manner. We describe how recent advances in quantitative imaging techniques overcome caveats of sequencing-based methods (Hi-C and related) by enabling direct visualization of transcription factors and chromatin at high resolution, from single genes to the whole nucleus. We discuss the contribution of fluorescence imaging to deciphering the principles underlying this coordination within the crowded nuclear space in living cells and discuss challenges ahead.
Collapse
Affiliation(s)
- Haitham A Shaban
- Spectroscopy Department, Physics Division, National Research Centre, Dokki, Cairo, 12622, Egypt.
- Current Address: Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Roman Barth
- Department of Bionanoscience, Delft University of Technology, 2628 CJ, Delft, The Netherlands
| | - Kerstin Bystricky
- Laboratoire de Biologie Moléculaire Eucaryote (LBME), Centre de Biologie Intégrative (CBI), CNRS, UPS, University of Toulouse, 31062, Toulouse, France.
- Institut Universitaire de France (IUF), Paris, France.
| |
Collapse
|
16
|
Lee MS, Hung CS, Phillips DA, Buck CC, Gupta MK, Lux MW. Silk fibroin as an additive for cell-free protein synthesis. Synth Syst Biotechnol 2020; 5:145-154. [PMID: 32637668 PMCID: PMC7320238 DOI: 10.1016/j.synbio.2020.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/15/2020] [Accepted: 06/15/2020] [Indexed: 01/06/2023] Open
Abstract
Cell-free systems contain many proteins and metabolites required for complex functions such as transcription and translation or multi-step metabolic conversions. Research into expanding the delivery of these systems by drying or by embedding into other materials is enabling new applications in sensing, point-of-need manufacturing, and responsive materials. Meanwhile, silk fibroin from the silk worm, Bombyx mori, has received attention as a protective additive for dried enzyme formulations and as a material to build biocompatible hydrogels for controlled localization or delivery of biomolecular cargoes. In this work, we explore the effects of silk fibroin as an additive in cell-free protein synthesis (CFPS) reactions. Impacts of silk fibroin on CFPS activity and stability after drying, as well as the potential for incorporation of CFPS into hydrogels of crosslinked silk fibroin are assessed. We find that simple addition of silk fibroin increased productivity of the CFPS reactions by up to 42%, which we attribute to macromolecular crowding effects. However, we did not find evidence that silk fibroin provides a protective effects after drying as previously described for purified enzymes. Further, the enzymatic crosslinking transformations of silk fibroin typically used to form hydrogels are inhibited in the presence of the CFPS reaction mixture. Crosslinking attempts did not impact CFPS activity, but did yield localized protein aggregates rather than a hydrogel. We discuss the mechanisms at play in these results and how the silk fibroin-CFPS system might be improved for the design of cell-free devices.
Collapse
Affiliation(s)
- Marilyn S. Lee
- US Army Combat Capabilities Development Command Chemical and Biological Center, 8567 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010, USA
| | - Chia-Suei Hung
- US Air Force Research Laboratory, 2179 12th St., B652/R122 Wright-Patterson Air Force Base, OH, 45433, USA
| | - Daniel A. Phillips
- US Naval Research Laboratory Center for Bio/Molecular Science and Engineering, Bldg. 42, Room 303 4555 Overlook Ave. Washington, DC 20375, UES Inc., 4401 Dayton Xenia Rd., Beavercreek, OH 45432, USA
| | - Chelsea C. Buck
- US Air Force Research Laboratory, 2179 12th St., B652/R122 Wright-Patterson Air Force Base, OH, 45433, USA
- US Naval Research Laboratory Center for Bio/Molecular Science and Engineering, Bldg. 42, Room 303 4555 Overlook Ave. Washington, DC 20375, UES Inc., 4401 Dayton Xenia Rd., Beavercreek, OH 45432, USA
| | - Maneesh K. Gupta
- US Air Force Research Laboratory, 2179 12th St., B652/R122 Wright-Patterson Air Force Base, OH, 45433, USA
| | - Matthew W. Lux
- US Army Combat Capabilities Development Command Chemical and Biological Center, 8567 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010, USA
| |
Collapse
|
17
|
Abstract
To date, single molecule studies have been reliant on tethering or confinement to achieve long duration and high temporal resolution measurements. Here, we present a 3D single-molecule active real-time tracking method (3D-SMART) which is capable of locking on to single fluorophores in solution for minutes at a time with photon limited temporal resolution. As a demonstration, 3D-SMART is applied to actively track single Atto 647 N fluorophores in 90% glycerol solution with an average duration of ~16 s at count rates of ~10 kHz. Active feedback tracking is further applied to single proteins and nucleic acids, directly measuring the diffusion of various lengths (99 to 1385 bp) of single DNA molecules at rates up to 10 µm2/s. In addition, 3D-SMART is able to quantify the occupancy of single Spinach2 RNA aptamers and capture active transcription on single freely diffusing DNA. 3D-SMART represents a critical step towards the untethering of single molecule spectroscopy. Single molecule observation has been limited to tethered molecules to ensure that the target remains in the field of view (FOV). Here, the authors develop a real-time tracking method that locks onto rapidly diffusing targets and tracks them in a 3D volume, enabling single molecules to remain in the FOV for minutes at a time.
Collapse
|
18
|
De Pieri A, Rana S, Korntner S, Zeugolis DI. Seaweed polysaccharides as macromolecular crowding agents. Int J Biol Macromol 2020; 164:434-446. [PMID: 32679331 DOI: 10.1016/j.ijbiomac.2020.07.087] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
Abstract
Development of mesenchymal stem cell-based tissue engineered implantable devices requires prolonged in vitro culture for the development of a three-dimensional implantable device, which leads to phenotypic drift, thus hindering the clinical translation and commercialisation of such approaches. Macromolecular crowding, a biophysical phenomenon based on the principles of excluded-volume effect, dramatically accelerates and increases extracellular matrix deposition during in vitro culture. However, the optimal macromolecular crowder is still elusive. Herein, we evaluated the biophysical properties of various concentrations of different seaweed in origin sulphated polysaccharides and their effect on human adipose derived stem cell cultures. Carrageenan, possibly due to its high sulphation degree, exhibited the highest negative charge values. No correlation was observed between the different concentrations of the crowders and charge, polydispersity index, hydrodynamic radius and fraction volume occupancy across all crowders. None of the crowders, but arabinogalactan, negatively affected cell viability. Carrageenan, fucoidan, galactofucan and ulvan increased extracellular matrix (especially collagen type I and collagen type V) deposition. Carrageenan induced the highest osteogenic effect and galactofucan and fucoidan demonstrated the highest chondrogenic effect. All crowders were relatively ineffective with respect to adipogenesis. Our data highlight the potential of sulphated seaweed polysaccharides for tissue engineering purposes.
Collapse
Affiliation(s)
- Andrea De Pieri
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland; Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland; Proxy Biomedical Ltd., Coilleach, Spiddal, Galway, Ireland
| | - Shubhasmin Rana
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland; Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Stefanie Korntner
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland; Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland; Science Foundation Ireland (SFI) Centre for Research in Medical Devices (CÚRAM), Biomedical Sciences Building, National University of Ireland Galway (NUI Galway), Galway, Ireland.
| |
Collapse
|
19
|
Manzanera M. Dealing with water stress and microbial preservation. Environ Microbiol 2020; 23:3351-3359. [PMID: 32452073 DOI: 10.1111/1462-2920.15096] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 01/31/2023]
Abstract
The relevance of preserving microorganisms has been well accepted for several decades. Interest is now shifting towards investigating adequate preservation methods to improve microbial survival rates and to preserve new taxa of previously considered unculturable microorganisms. In addition, a growing interest in preserving fragile microbial consortia or communities with biotechnological interest motivates the improvement of preservation methods. In the present study, we reviewed the effect of water availability in microbial diversity shift. We describe the effect of drought on microorganisms at the molecular level and their molecular responses to this life-threatening challenge focusing on the production of xeroprotectants. We also review the interspecies interactions of those drought-tolerant microorganisms with other sensitive organisms including neighbouring prokaryotes and eukaryotes such as plants, and the potential role of these microorganisms at determining the ecological composition of stressed environments. We emphasize the importance of applying the knowledge derived from the molecular mechanisms used by desiccation-tolerant microorganisms for the improvement of the preservation techniques. An overview of the current and newer techniques for preserving microorganisms and microbial communities is provided. The biotechnological interest in preserving pure cultures, microbial consortia and communities is also discussed.
Collapse
Affiliation(s)
- Maximino Manzanera
- Department of Microbiology, Institute for Water Research, University of Granada, Granada, Spain
| |
Collapse
|
20
|
Abstract
The disaccharide trehalose is accumulated in the cytoplasm of some organisms in response to harsh environmental conditions. Trehalose biosynthesis and accumulation are important for the survival of such organisms by protecting the structure and function of proteins and membranes. Trehalose affects the dynamics of proteins and water molecules in the bulk and the protein hydration shell. Enzyme catalysis and other processes dependent on protein dynamics are affected by the viscosity generated by trehalose, as described by the Kramers’ theory of rate reactions. Enzyme/protein stabilization by trehalose against thermal inactivation/unfolding is also explained by the viscosity mediated hindering of the thermally generated structural dynamics, as described by Kramers’ theory. The analysis of the relationship of viscosity–protein dynamics, and its effects on enzyme/protein function and other processes (thermal inactivation and unfolding/folding), is the focus of the present work regarding the disaccharide trehalose as the viscosity generating solute. Finally, trehalose is widely used (alone or in combination with other compounds) in the stabilization of enzymes in the laboratory and in biotechnological applications; hence, considering the effect of viscosity on catalysis and stability of enzymes may help to improve the results of trehalose in its diverse uses/applications.
Collapse
|
21
|
Vasilakou E, van Loosdrecht MCM, Wahl SA. Escherichia coli metabolism under short-term repetitive substrate dynamics: adaptation and trade-offs. Microb Cell Fact 2020; 19:116. [PMID: 32471427 PMCID: PMC7260802 DOI: 10.1186/s12934-020-01379-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/25/2020] [Indexed: 12/04/2022] Open
Abstract
Background Microbial metabolism is highly dependent on the environmental conditions. Especially, the substrate concentration, as well as oxygen availability, determine the metabolic rates. In large-scale bioreactors, microorganisms encounter dynamic conditions in substrate and oxygen availability (mixing limitations), which influence their metabolism and subsequently their physiology. Earlier, single substrate pulse experiments were not able to explain the observed physiological changes generated under large-scale industrial fermentation conditions. Results In this study we applied a repetitive feast–famine regime in an aerobic Escherichia coli culture in a time-scale of seconds. The regime was applied for several generations, allowing cells to adapt to the (repetitive) dynamic environment. The observed response was highly reproducible over the cycles, indicating that cells were indeed fully adapted to the regime. We observed an increase of the specific substrate and oxygen consumption (average) rates during the feast–famine regime, compared to a steady-state (chemostat) reference environment. The increased rates at same (average) growth rate led to a reduced biomass yield (30% lower). Interestingly, this drop was not followed by increased by-product formation, pointing to the existence of energy-spilling reactions. During the feast–famine cycle, the cells rapidly increased their uptake rate. Within 10 s after the beginning of the feeding, the substrate uptake rate was higher (4.68 μmol/gCDW/s) than reported during batch growth (3.3 μmol/gCDW/s). The high uptake led to an accumulation of several intracellular metabolites, during the feast phase, accounting for up to 34% of the carbon supplied. Although the metabolite concentrations changed rapidly, the cellular energy charge remained unaffected, suggesting well-controlled balance between ATP producing and ATP consuming reactions. Conclusions The adaptation of the physiology and metabolism of E. coli under substrate dynamics, representative for large-scale fermenters, revealed the existence of several cellular mechanisms coping with stress. Changes in the substrate uptake system, storage potential and energy-spilling processes resulted to be of great importance. These metabolic strategies consist a meaningful step to further tackle reduced microbial performance, observed under large-scale cultivations.
Collapse
Affiliation(s)
- Eleni Vasilakou
- Department of Biotechnology, Delft University of Technology, Van der Maasweg, 2629 HZ, Delft, The Netherlands.
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Van der Maasweg, 2629 HZ, Delft, The Netherlands
| | - S Aljoscha Wahl
- Department of Biotechnology, Delft University of Technology, Van der Maasweg, 2629 HZ, Delft, The Netherlands.
| |
Collapse
|