1
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Welles RM, Sojitra KA, Garabedian MV, Xia B, Wang W, Guan M, Regy RM, Gallagher ER, Hammer DA, Mittal J, Good MC. Determinants that enable disordered protein assembly into discrete condensed phases. Nat Chem 2024; 16:1062-1072. [PMID: 38316988 DOI: 10.1038/s41557-023-01423-7] [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: 03/10/2023] [Accepted: 12/13/2023] [Indexed: 02/07/2024]
Abstract
Cells harbour numerous mesoscale membraneless compartments that house specific biochemical processes and perform distinct cellular functions. These protein- and RNA-rich bodies are thought to form through multivalent interactions among proteins and nucleic acids, resulting in demixing via liquid-liquid phase separation. Proteins harbouring intrinsically disordered regions (IDRs) predominate in membraneless organelles. However, it is not known whether IDR sequence alone can dictate the formation of distinct condensed phases. We identified a pair of IDRs capable of forming spatially distinct condensates when expressed in cells. When reconstituted in vitro, these model proteins do not co-partition, suggesting condensation specificity is encoded directly in the polypeptide sequences. Through computational modelling and mutagenesis, we identified the amino acids and chain properties governing homotypic and heterotypic interactions that direct selective condensation. These results form the basis of physicochemical principles that may direct subcellular organization of IDRs into specific condensates and reveal an IDR code that can guide construction of orthogonal membraneless compartments.
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Affiliation(s)
- Rachel M Welles
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kandarp A Sojitra
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Mikael V Garabedian
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Boao Xia
- Bioengineering Graduate Program, Rice University, Houston, TX, USA
| | - Wentao Wang
- Bioengineering Graduate Program, University of Pennsylvania, Philadelphia, PA, USA
| | - Muyang Guan
- Chemical and Biomolecular Engineering Graduate Program, University of Pennsylvania, Philadelphia, PA, USA
| | - Roshan M Regy
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Elizabeth R Gallagher
- Cell and Molecular Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel A Hammer
- Bioengineering Graduate Program, University of Pennsylvania, Philadelphia, PA, USA
- Chemical and Biomolecular Engineering Graduate Program, University of Pennsylvania, Philadelphia, PA, USA
- Chemical and Biomolecular Engineering Department, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
- Department of Chemistry, Texas A&M University, College Station, TX, USA.
- Interdisciplinary Graduate Program in Genetics and Genomics, Texas A&M University, College Station, TX, USA.
| | - Matthew C Good
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Bioengineering Graduate Program, University of Pennsylvania, Philadelphia, PA, USA.
- Cell and Molecular Biology Graduate Program, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
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2
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Valverde JM, Dubra G, Phillips M, Haider A, Elena-Real C, Fournet A, Alghoul E, Chahar D, Andrés-Sanchez N, Paloni M, Bernadó P, van Mierlo G, Vermeulen M, van den Toorn H, Heck AJR, Constantinou A, Barducci A, Ghosh K, Sibille N, Knipscheer P, Krasinska L, Fisher D, Altelaar M. A cyclin-dependent kinase-mediated phosphorylation switch of disordered protein condensation. Nat Commun 2023; 14:6316. [PMID: 37813838 PMCID: PMC10562473 DOI: 10.1038/s41467-023-42049-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/28/2023] [Indexed: 10/11/2023] Open
Abstract
Cell cycle transitions result from global changes in protein phosphorylation states triggered by cyclin-dependent kinases (CDKs). To understand how this complexity produces an ordered and rapid cellular reorganisation, we generated a high-resolution map of changing phosphosites throughout unperturbed early cell cycles in single Xenopus embryos, derived the emergent principles through systems biology analysis, and tested them by biophysical modelling and biochemical experiments. We found that most dynamic phosphosites share two key characteristics: they occur on highly disordered proteins that localise to membraneless organelles, and are CDK targets. Furthermore, CDK-mediated multisite phosphorylation can switch homotypic interactions of such proteins between favourable and inhibitory modes for biomolecular condensate formation. These results provide insight into the molecular mechanisms and kinetics of mitotic cellular reorganisation.
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Affiliation(s)
- Juan Manuel Valverde
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, 3584 CH, Utrecht, Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH, Utrecht, Netherlands
| | - Geronimo Dubra
- IGMM, CNRS, University of Montpellier, INSERM, Montpellier, France
- Equipe Labellisée LIGUE 2018, Ligue Nationale Contre le Cancer, Paris, France
| | - Michael Phillips
- Department of Physics and Astronomy, University of Denver, Denver, Co, 80208, USA
| | - Austin Haider
- Department of Molecular and Cellular Biophysics, University of Denver, 80208, Denver, Co, USA
| | | | - Aurélie Fournet
- CBS, CNRS, University of Montpellier, INSERM, Montpellier, France
| | - Emile Alghoul
- IGH, CNRS, University of Montpellier, Montpellier, France
| | - Dhanvantri Chahar
- IGMM, CNRS, University of Montpellier, INSERM, Montpellier, France
- Equipe Labellisée LIGUE 2018, Ligue Nationale Contre le Cancer, Paris, France
| | - Nuria Andrés-Sanchez
- IGMM, CNRS, University of Montpellier, INSERM, Montpellier, France
- Equipe Labellisée LIGUE 2018, Ligue Nationale Contre le Cancer, Paris, France
| | - Matteo Paloni
- Department of Physics and Astronomy, University of Denver, Denver, Co, 80208, USA
| | - Pau Bernadó
- CBS, CNRS, University of Montpellier, INSERM, Montpellier, France
| | - Guido van Mierlo
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, 6525 GA, The Netherlands
| | - Michiel Vermeulen
- Department of Molecular Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, Oncode Institute, Radboud University Nijmegen, Nijmegen, 6525 GA, The Netherlands
| | - Henk van den Toorn
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, 3584 CH, Utrecht, Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH, Utrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, 3584 CH, Utrecht, Netherlands
- Netherlands Proteomics Center, Padualaan 8, 3584 CH, Utrecht, Netherlands
| | | | | | - Kingshuk Ghosh
- Department of Physics and Astronomy, University of Denver, Denver, Co, 80208, USA
- Department of Molecular and Cellular Biophysics, University of Denver, 80208, Denver, Co, USA
| | - Nathalie Sibille
- CBS, CNRS, University of Montpellier, INSERM, Montpellier, France
| | - Puck Knipscheer
- Oncode Institute, Hubrecht Institute-KNAW and University Medical Center, Utrecht, 3584 CT, Netherlands
| | - Liliana Krasinska
- IGMM, CNRS, University of Montpellier, INSERM, Montpellier, France
- Equipe Labellisée LIGUE 2018, Ligue Nationale Contre le Cancer, Paris, France
| | - Daniel Fisher
- IGMM, CNRS, University of Montpellier, INSERM, Montpellier, France.
- Equipe Labellisée LIGUE 2018, Ligue Nationale Contre le Cancer, Paris, France.
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht, 3584 CH, Utrecht, Netherlands.
- Netherlands Proteomics Center, Padualaan 8, 3584 CH, Utrecht, Netherlands.
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3
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Yamada R, Takada S. Postsynaptic protein assembly in three and two dimensions studied by mesoscopic simulations. Biophys J 2023; 122:3395-3410. [PMID: 37496268 PMCID: PMC10465727 DOI: 10.1016/j.bpj.2023.07.015] [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: 03/01/2023] [Revised: 05/25/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023] Open
Abstract
Recently, cellular biomolecular condensates formed via phase separation have received considerable attention. While they can be formed either in cytosol (denoted as 3D) or beneath the membrane (2D), the underlying difference between the two has not been well clarified. To compare the phase behaviors in 3D and 2D, postsynaptic density (PSD) serves as a model system. PSD is a protein condensate located under the postsynaptic membrane that influences the localization of glutamate receptors and thus contributes to synaptic plasticity. Recent in vitro studies have revealed the formation of droplets of various soluble PSD proteins via liquid-liquid phase separation. However, it is unclear how these protein condensates are formed beneath the membrane and how they specifically affect the localization of glutamate receptors in the membrane. In this study, focusing on the mixture of a glutamate receptor complex, AMPAR-TARP, and a ubiquitous scaffolding protein, PSD-95, we constructed a mesoscopic model of protein-domain interactions in PSD and performed comparative molecular simulations. The results showed a sharp contrast in the phase behaviors of protein assemblies in 3D and those under the membrane (2D). A mixture of a soluble variant of the AMPAR-TARP complex and PSD-95 in the 3D system resulted in a phase-separated condensate, which was consistent with the experimental results. However, with identical domain interactions, AMPAR-TARP embedded in the membrane formed clusters with PSD-95, but did not form a stable separated phase. Thus, the cluster formation behaviors of PSD proteins in the 3D and 2D systems were distinct. The current study suggests that, more generally, stable phase separation can be more difficult to achieve in and beneath the membrane than in 3D systems.
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Affiliation(s)
- Risa Yamada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
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4
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Chattaraj A, Loew LM. The maximum solubility product marks the threshold for condensation of multivalent biomolecules. Biophys J 2023; 122:1678-1690. [PMID: 36987392 PMCID: PMC10183374 DOI: 10.1016/j.bpj.2023.03.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 02/08/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Clustering of weakly interacting multivalent biomolecules underlies the formation of membraneless compartments known as condensates. As opposed to single-component (homotypic) systems, the concentration dependence of multicomponent (heterotypic) condensate formation is not well understood. We previously proposed the solubility product (SP), the product of monomer concentrations in the dilute phase, as a tool for understanding the concentration dependence of multicomponent systems. In this study, we further explore the limits of the SP concept using spatial Langevin dynamics and rule-based stochastic simulations. We show, for a variety of idealized molecular structures, how the maximum SP coincides with the onset of the phase transition, i.e., the formation of large clusters. We reveal the importance of intracluster binding in steering the free and cluster phase molecular distributions. We also show how structural features of biomolecules shape the SP profiles. The interplay of flexibility, length, and steric hindrance of linker regions controls the phase transition threshold. Remarkably, when SPs are normalized to nondimensional variables and plotted against the concentration scaled to the threshold for phase transition, the curves all coincide independent of the structural features of the binding partners. Similar coincidence is observed for the normalized clustering versus concentration plots. Overall, the principles derived from these systematic models will help guide and interpret in vitro and in vivo experiments on the biophysics of biomolecular condensates.
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Affiliation(s)
- Aniruddha Chattaraj
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut.
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5
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Wang WJ, Tan CP, Mao ZW. Metals and inorganic molecules in regulating protein and nucleic acid phase separation. Curr Opin Chem Biol 2023; 74:102308. [PMID: 37088005 DOI: 10.1016/j.cbpa.2023.102308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 04/25/2023]
Abstract
The realization that liquid-liquid phase separation (LLPS) underlies the formation of membraneless compartments in cells has motivated efforts to modulate the condensation process of biomolecules. Increasing evidence shows that metals and inorganic molecules abundantly distributed in cells play important roles in the regulation of biomolecular condensation. Herein, we briefly reviewed the background of biomacromolecular phase separation and summarized the recent research progress on the roles of metals and inorganic molecules in regulating protein and nucleic acid phase separation in vitro and in cells.
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Affiliation(s)
- Wen-Jin Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China.
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China.
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6
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Phan LX, Chamorro VC, Martinez-Seara H, Crain J, Sansom MSP, Tucker SJ. Influence of electronic polarization on the binding of anions to a chloride-pumping rhodopsin. Biophys J 2023; 122:1548-1556. [PMID: 36945777 PMCID: PMC10147828 DOI: 10.1016/j.bpj.2023.03.026] [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: 01/03/2023] [Revised: 03/07/2023] [Accepted: 03/16/2023] [Indexed: 03/23/2023] Open
Abstract
The functional properties of some biological ion channels and membrane transport proteins are proposed to exploit anion-hydrophobic interactions. Here, we investigate a chloride-pumping rhodopsin as an example of a membrane protein known to contain a defined anion binding site composed predominantly of hydrophobic residues. Using molecular dynamics simulations, we explore Cl- binding to this hydrophobic site and compare the dynamics arising when electronic polarization is neglected (CHARMM36 [c36] fixed-charge force field), included implicitly (via the prosECCo force field), or included explicitly (through the polarizable force field, AMOEBA). Free energy landscapes of Cl- moving out of the binding site and into bulk solution demonstrate that the inclusion of polarization results in stronger ion binding and a second metastable binding site in chloride-pumping rhodopsin. Simulations focused on this hydrophobic binding site also indicate longer binding durations and closer ion proximity when polarization is included. Furthermore, simulations reveal that Cl- within this binding site interacts with an adjacent loop to facilitate rebinding events that are not observed when polarization is neglected. These results demonstrate how the inclusion of polarization can influence the behavior of anions within protein binding sites and can yield results comparable with more accurate and computationally demanding methods.
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Affiliation(s)
- Linda X Phan
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK; Department of Biochemistry, University of Oxford, Oxford, UK
| | - Victor Cruces Chamorro
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague 6, Czech Republic
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague 6, Czech Republic
| | - Jason Crain
- Department of Biochemistry, University of Oxford, Oxford, UK; IBM Research Europe, Hartree Centre, Daresbury, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Stephen J Tucker
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK.
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7
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Zhang M, Xue B, Li Q, Shi R, Cao Y, Wang W, Li J. Sequence Tendency for the Interaction between Low-Complexity Intrinsically Disordered Proteins. JACS AU 2023; 3:93-104. [PMID: 36711093 PMCID: PMC9875249 DOI: 10.1021/jacsau.2c00414] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Reversible interaction between intrinsically disordered proteins (IDPs) is considered as the driving force for liquid-liquid phase separation (LLPS), while the detailed description of such a transient interaction process still remains a challenge. And the mechanisms underlying the behavior of IDP interaction, for example, the possible relationship with its inherent conformational fluctuations and sequence features, remain elusive. Here, we use atomistic molecular dynamics (MD) simulation to investigate the reversible association of the LAF-1 RGG domain, the IDP with ultra-low LLPS concentration (0.06 mM). We find that the duration of the association between two RGG domains is highly heterogeneous, and the sustained associations essentially dominate the IDP interaction. More interestingly, such sustained associations are mediated by a finite region, that is, the C-terminal region 138-168 (denoted as a contact-prone region). We noticed that such sequence tendency is attributed to the extended conformation of the RGG domain during its inherent conformational fluctuations. Hence, our results suggest that there is a certain region in this low-complexity IDP which can essentially dominate their interaction and should be also important to the LLPS. And the inherent conformational fluctuations are actually essential for the emergence of such a hot region of IDP interaction. The importance of this hot region to LLPS is verified by experiment.
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Affiliation(s)
- Moxin Zhang
- Zhejiang
Province Key Laboratory of Quantum Technology and Device, School of
Physics, Zhejiang University, Hangzhou310058, China
| | - Bin Xue
- Collaborative
Innovation Center of Advanced Microstructures, National Laboratory
of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing210093, China
| | - Qingtai Li
- Collaborative
Innovation Center of Advanced Microstructures, National Laboratory
of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing210093, China
| | - Rui Shi
- Zhejiang
Province Key Laboratory of Quantum Technology and Device, School of
Physics, Zhejiang University, Hangzhou310058, China
| | - Yi Cao
- Collaborative
Innovation Center of Advanced Microstructures, National Laboratory
of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing210093, China
| | - Wei Wang
- Collaborative
Innovation Center of Advanced Microstructures, National Laboratory
of Solid State Microstructure, Department of Physics, Nanjing University, Nanjing210093, China
| | - Jingyuan Li
- Zhejiang
Province Key Laboratory of Quantum Technology and Device, School of
Physics, Zhejiang University, Hangzhou310058, China
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8
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He G, GrandPre T, Wilson H, Zhang Y, Jonikas MC, Wingreen NS, Wang Q. Phase-separating pyrenoid proteins form complexes in the dilute phase. Commun Biol 2023; 6:19. [PMID: 36611062 PMCID: PMC9825591 DOI: 10.1038/s42003-022-04373-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/13/2022] [Indexed: 01/09/2023] Open
Abstract
While most studies of biomolecular phase separation have focused on the condensed phase, relatively little is known about the dilute phase. Theory suggests that stable complexes form in the dilute phase of two-component phase-separating systems, impacting phase separation; however, these complexes have not been interrogated experimentally. We show that such complexes indeed exist, using an in vitro reconstitution system of a phase-separated organelle, the algal pyrenoid, consisting of purified proteins Rubisco and EPYC1. Applying fluorescence correlation spectroscopy (FCS) to measure diffusion coefficients, we found that complexes form in the dilute phase with or without condensates present. The majority of these complexes contain exactly one Rubisco molecule. Additionally, we developed a simple analytical model which recapitulates experimental findings and provides molecular insights into the dilute phase organization. Thus, our results demonstrate the existence of protein complexes in the dilute phase, which could play important roles in the stability, dynamics, and regulation of condensates.
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Affiliation(s)
- Guanhua He
- grid.16750.350000 0001 2097 5006Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA
| | - Trevor GrandPre
- grid.16750.350000 0001 2097 5006Department of Physics, Princeton University, Princeton, NJ 08544 USA ,grid.16750.350000 0001 2097 5006Center for the Physics of Biological Function, Princeton University, Princeton, NJ USA
| | - Hugh Wilson
- grid.16750.350000 0001 2097 5006Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544 USA
| | - Yaojun Zhang
- grid.16750.350000 0001 2097 5006Center for the Physics of Biological Function, Princeton University, Princeton, NJ USA ,grid.21107.350000 0001 2171 9311Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD USA ,grid.21107.350000 0001 2171 9311Department of Biophysics, Johns Hopkins University, Baltimore, MD USA
| | - Martin C. Jonikas
- grid.16750.350000 0001 2097 5006Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA ,grid.16750.350000 0001 2097 5006Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08544 USA
| | - Ned S. Wingreen
- grid.16750.350000 0001 2097 5006Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA ,grid.16750.350000 0001 2097 5006Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544 USA
| | - Quan Wang
- grid.16750.350000 0001 2097 5006Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544 USA ,grid.419635.c0000 0001 2203 7304Present Address: Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MA 20892 USA
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9
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Lin YH, Wessén J, Pal T, Das S, Chan HS. Numerical Techniques for Applications of Analytical Theories to Sequence-Dependent Phase Separations of Intrinsically Disordered Proteins. Methods Mol Biol 2023; 2563:51-94. [PMID: 36227468 DOI: 10.1007/978-1-0716-2663-4_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Biomolecular condensates, physically underpinned to a significant extent by liquid-liquid phase separation (LLPS), are now widely recognized by numerous experimental studies to be of fundamental biological, biomedical, and biophysical importance. In the face of experimental discoveries, analytical formulations emerged as a powerful yet tractable tool in recent theoretical investigations of the role of LLPS in the assembly and dissociation of these condensates. The pertinent LLPS often involves, though not exclusively, intrinsically disordered proteins engaging in multivalent interactions that are governed by their amino acid sequences. For researchers interested in applying these theoretical methods, here we provide a practical guide to a set of computational techniques devised for extracting sequence-dependent LLPS properties from analytical formulations. The numerical procedures covered include those for the determination of spinodal and binodal phase boundaries from a general free energy function with examples based on the random phase approximation in polymer theory, construction of tie lines for multiple-component LLPS, and field-theoretic simulation of multiple-chain heteropolymeric systems using complex Langevin dynamics. Since a more accurate physical picture often requires comparing analytical theory against explicit-chain model predictions, a commonly utilized methodology for coarse-grained molecular dynamics simulations of sequence-specific LLPS is also briefly outlined.
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Affiliation(s)
- Yi-Hsuan Lin
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
- Molecular Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Jonas Wessén
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Tanmoy Pal
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Suman Das
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Hue Sun Chan
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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10
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Wessén J, Das S, Pal T, Chan HS. Analytical Formulation and Field-Theoretic Simulation of Sequence-Specific Phase Separation of Protein-Like Heteropolymers with Short- and Long-Spatial-Range Interactions. J Phys Chem B 2022; 126:9222-9245. [PMID: 36343363 DOI: 10.1021/acs.jpcb.2c06181] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A theory for sequence-dependent liquid-liquid phase separation (LLPS) of intrinsically disordered proteins (IDPs) in the study of biomolecular condensates is formulated by extending the random phase approximation (RPA) and field-theoretic simulation (FTS) of heteropolymers with spatially long-range Coulomb interactions to include the fundamental effects of short-range, hydrophobic-like interactions between amino acid residues. To this end, short-range effects are modeled by Yukawa interactions between multiple nonelectrostatic charges derived from an eigenvalue decomposition of pairwise residue-residue contact energies. Chain excluded volume is afforded by incompressibility constraints. A mean-field approximation leads to an effective Flory-Huggins χ parameter, which, in conjunction with RPA, accounts for the contact-interaction effects of amino acid composition and the sequence-pattern effects of long-range electrostatics in IDP LLPS, whereas FTS based on the formulation provides full sequence dependence for both short- and long-range interactions. This general approach is illustrated here by applications to variants of a natural IDP in the context of several different amino-acid interaction schemes as well as a set of different model hydrophobic-polar sequences sharing the same composition. Effectiveness of the methodology is verified by coarse-grained explicit-chain molecular dynamics simulations.
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Affiliation(s)
- Jonas Wessén
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Suman Das
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Tanmoy Pal
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Hue Sun Chan
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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11
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Poly(ADP-ribose) in Condensates: The PARtnership of Phase Separation and Site-Specific Interactions. Int J Mol Sci 2022; 23:ijms232214075. [PMID: 36430551 PMCID: PMC9694962 DOI: 10.3390/ijms232214075] [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: 10/14/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/17/2022] Open
Abstract
Biomolecular condensates are nonmembrane cellular compartments whose formation in many cases involves phase separation (PS). Despite much research interest in this mechanism of macromolecular self-organization, the concept of PS as applied to a live cell faces certain challenges. In this review, we discuss a basic model of PS and the role of site-specific interactions and percolation in cellular PS-related events. Using a multivalent poly(ADP-ribose) molecule as an example, which has high PS-driving potential due to its structural features, we consider how site-specific interactions and network formation are involved in the formation of phase-separated cellular condensates.
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12
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Murata Y, Niina T, Takada S. The stoichiometric interaction model for mesoscopic MD simulations of liquid-liquid phase separation. Biophys J 2022; 121:4382-4393. [PMID: 36199253 PMCID: PMC9703007 DOI: 10.1016/j.bpj.2022.10.001] [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: 03/11/2022] [Revised: 06/28/2022] [Accepted: 09/30/2022] [Indexed: 12/14/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) has received considerable attention in recent years for explaining the formation of cellular biomolecular condensates. The fluidity and the complexity of their components make molecular simulation approaches indispensable for gaining structural insights. Domain-resolution mesoscopic model simulations have been explored for cases in which condensates are formed by multivalent proteins with tandem domains. One problem with this approach is that interdomain pairwise interactions cannot regulate the valency of the binding domains. To overcome this problem, we propose a new potential, the stoichiometric interaction (SI) potential. First, we verified that the SI potential maintained the valency of the interacting domains for the test systems. We then examined a well-studied LLPS model system containing tandem repeats of SH3 domains and proline-rich motifs. We found that the SI potential alone cannot reproduce the phase diagram of LLPS quantitatively. We had to combine the SI and a pairwise interaction; the former and the latter represent the specific and nonspecific interactions, respectively. Biomolecular condensates with the mixed SI and pairwise interaction exhibited fluidity, whereas those with the pairwise interaction alone showed no detectable diffusion. We also compared the phase diagrams of the systems containing different numbers of tandem domains with those obtained from the experiments and found quantitative agreement in all but one case.
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Affiliation(s)
- Yutaka Murata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Toru Niina
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
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13
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Alemasova EE, Lavrik OI. A sePARate phase? Poly(ADP-ribose) versus RNA in the organization of biomolecular condensates. Nucleic Acids Res 2022; 50:10817-10838. [PMID: 36243979 DOI: 10.1093/nar/gkac866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/14/2022] [Accepted: 10/09/2022] [Indexed: 11/13/2022] Open
Abstract
Condensates are biomolecular assemblies that concentrate biomolecules without the help of membranes. They are morphologically highly versatile and may emerge via distinct mechanisms. Nucleic acids-DNA, RNA and poly(ADP-ribose) (PAR) play special roles in the process of condensate organization. These polymeric scaffolds provide multiple specific and nonspecific interactions during nucleation and 'development' of macromolecular assemblages. In this review, we focus on condensates formed with PAR. We discuss to what extent the literature supports the phase separation origin of these structures. Special attention is paid to similarities and differences between PAR and RNA in the process of dynamic restructuring of condensates during their functioning.
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Affiliation(s)
- Elizaveta E Alemasova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia
| | - Olga I Lavrik
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia.,Novosibirsk State University, Novosibirsk 630090, Russia
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14
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Ghosh K, Huihui J, Phillips M, Haider A. Rules of Physical Mathematics Govern Intrinsically Disordered Proteins. Annu Rev Biophys 2022; 51:355-376. [PMID: 35119946 PMCID: PMC9190209 DOI: 10.1146/annurev-biophys-120221-095357] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In stark contrast to foldable proteins with a unique folded state, intrinsically disordered proteins and regions (IDPs) persist in perpetually disordered ensembles. Yet an IDP ensemble has conformational features-even when averaged-that are specific to its sequence. In fact, subtle changes in an IDP sequence can modulate its conformational features and its function. Recent advances in theoretical physics reveal a set of elegant mathematical expressions that describe the intricate relationships among IDP sequences, their ensemble conformations, and the regulation of their biological functions. These equations also describe the molecular properties of IDP sequences that predict similarities and dissimilarities in their functions and facilitate classification of sequences by function, an unmet challenge to traditional bioinformatics. These physical sequence-patterning metrics offer a promising new avenue for advancing synthetic biology at a time when multiple novel functional modes mediated by IDPs are emerging.
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Affiliation(s)
- Kingshuk Ghosh
- Department of Physics and Astronomy, University of Denver, Denver, Colorado, USA,Molecular and Cellular Biophysics Program, University of Denver, Denver, Colorado, USA
| | - Jonathan Huihui
- Department of Physics and Astronomy, University of Denver, Denver, Colorado, USA
| | - Michael Phillips
- Department of Physics and Astronomy, University of Denver, Denver, Colorado, USA
| | - Austin Haider
- Molecular and Cellular Biophysics Program, University of Denver, Denver, Colorado, USA
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15
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Zhao H, Nguyen A, Wu D, Li Y, Hassan SA, Chen J, Shroff H, Piszczek G, Schuck P. Plasticity in structure and assembly of SARS-CoV-2 nucleocapsid protein. PNAS NEXUS 2022; 1:pgac049. [PMID: 35783502 PMCID: PMC9235412 DOI: 10.1093/pnasnexus/pgac049] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/19/2022] [Indexed: 02/06/2023]
Abstract
Worldwide SARS-CoV-2 sequencing efforts track emerging mutations in its spike protein, as well as characteristic mutations in other viral proteins. Besides their epidemiological importance, the observed SARS-CoV-2 sequences present an ensemble of viable protein variants, and thereby a source of information on viral protein structure and function. Charting the mutational landscape of the nucleocapsid (N) protein that facilitates viral assembly, we observe variability exceeding that of the spike protein, with more than 86% of residues that can be substituted, on average by three to four different amino acids. However, mutations exhibit an uneven distribution that tracks known structural features but also reveals highly protected stretches of unknown function. One of these conserved regions is in the central disordered linker proximal to the N-G215C mutation that has become dominant in the Delta variant, outcompeting G215 variants without further spike or N-protein substitutions. Structural models suggest that the G215C mutation stabilizes conserved transient helices in the disordered linker serving as protein-protein interaction interfaces. Comparing Delta variant N-protein to its ancestral version in biophysical experiments, we find a significantly more compact and less disordered structure. N-G215C exhibits substantially stronger self-association, shifting the unliganded protein from a dimeric to a tetrameric oligomeric state, which leads to enhanced coassembly with nucleic acids. This suggests that the sequence variability of N-protein is mirrored by high plasticity of N-protein biophysical properties, which we hypothesize can be exploited by SARS-CoV-2 to achieve greater efficiency of viral assembly, and thereby enhanced infectivity.
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Affiliation(s)
- Huaying Zhao
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ai Nguyen
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Di Wu
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sergio A Hassan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hari Shroff
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Grzegorz Piszczek
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter Schuck
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
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16
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Wessén J, Pal T, Chan HS. Field theory description of ion association in re-entrant phase separation of polyampholytes. J Chem Phys 2022; 156:194903. [DOI: 10.1063/5.0088326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Phase separation of several different overall neutral polyampholyte species (with zero net charge) is studied in solution with two oppositely charged ion species that can form ion-pairs through an association reaction. A field theory description of the system, that treats polyampholyte charge sequence dependent electrostatic interactions as well as excluded volume effects, is hereby given. Interestingly, analysis of the model using random phase approximation and field theoretic simulation consistently show evidence of a re-entrant polyampholyte phase separation at high ion concentrations when there is an overall decrease of volume upon ion-association. As an illustration of the ramifications of our theoretical framework, several polyampholyte concentration vs ion concentration phase diagrams under constant temperature conditions are presented to elucidate the dependence of phase separation behavior on polyampholyte sequence charge pattern as well as ion-pair dissociation constant, volumetric effects on ion association, solvent quality, and temperature.
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Affiliation(s)
- Jonas Wessén
- Department of Biochemsitry, University of Toronto, Canada
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17
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Cinar H, Oliva R, Wu H, Zhang M, Chan HS, Winter R. Effects of Cosolvents and Crowding Agents on the Stability and Phase Transition Kinetics of the SynGAP/PSD-95 Condensate Model of Postsynaptic Densities. J Phys Chem B 2022; 126:1734-1741. [PMID: 35171623 DOI: 10.1021/acs.jpcb.2c00794] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The SynGAP/PSD-95 binary protein system serves as a simple mimicry of postsynaptic densities (PSDs), which are protein assemblies based largely on liquid-liquid phase separation (LLPS), that are located underneath the plasma membrane of excitatory synapses. Surprisingly, the LLPS of the SynGAP/PSD-95 system is much more pressure sensitive than typical folded states of proteins or nucleic acids. It was found that phase-separated SynGAP/PSD-95 droplets dissolve into a homogeneous solution at a pressure of tens to hundred bar. Since organisms in the deep sea are exposed to pressures of up to ∼1000 bar, this observation suggests that deep-sea organisms must counteract the high pressure sensitivity of PSDs to avoid neurological impairment. We demonstrate here that the compatible osmolyte trimethylamine-N-oxide (TMAO) as well as macromolecular crowding agents at moderate concentrations can mitigate the deleterious effect of pressure on SynGAP/PSD-95 droplet stability, extending stable LLPS up to almost a kbar level. Moreover, the formation of SynGAP/PSD-95 droplets is a very rapid process that can be switched on and off in seconds. In contrast with the marked effects of the cosolutes on droplet stability, at the cosolutes' respective biologically relevant concentrations, their impact on the phase transformation kinetics is rather small. Only a high TMAO concentration results in a significant kinetic retardation of LLPS. Taken together, these findings offer new biophysical insights into the neurological effects of hydrostatic pressure. In particular, our results indicate how pressure-induced neurological disorders might be alleviated by upregulating certain cosolutes in the cellular milieu.
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Affiliation(s)
- Hasan Cinar
- Physical Chemistry I - Biophysical Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227 Dortmund, Germany
| | - Rosario Oliva
- Physical Chemistry I - Biophysical Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227 Dortmund, Germany
| | - Haowei Wu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon 999077, Hong Kong, China.,School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hue Sun Chan
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Roland Winter
- Physical Chemistry I - Biophysical Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Strasse 4a, 44227 Dortmund, Germany
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18
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Zhao H, Nguyen A, Wu D, Li Y, Hassan SA, Chen J, Shroff H, Piszczek G, Schuck P. Plasticity in structure and assembly of SARS-CoV-2 nucleocapsid protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.02.08.479556. [PMID: 35169797 PMCID: PMC8845419 DOI: 10.1101/2022.02.08.479556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Worldwide SARS-CoV-2 sequencing efforts track emerging mutations in its spike protein, as well as characteristic mutations in other viral proteins. Besides their epidemiological importance, the observed SARS-CoV-2 sequences present an ensemble of viable protein variants, and thereby a source of information on viral protein structure and function. Charting the mutational landscape of the nucleocapsid (N) protein that facilitates viral assembly, we observe variability exceeding that of the spike protein, with more than 86% of residues that can be substituted, on average by 3-4 different amino acids. However, mutations exhibit an uneven distribution that tracks known structural features but also reveals highly protected stretches of unknown function. One of these conserved regions is in the central disordered linker proximal to the N-G215C mutation that has become dominant in the Delta variant, outcompeting G215 variants without further spike or N-protein substitutions. Structural models suggest that the G215C mutation stabilizes conserved transient helices in the disordered linker serving as protein-protein interaction interfaces. Comparing Delta variant N-protein to its ancestral version in biophysical experiments, we find a significantly more compact and less disordered structure. N-G215C exhibits substantially stronger self-association, shifting the unliganded protein from a dimeric to a tetrameric oligomeric state, which leads to enhanced co-assembly with nucleic acids. This suggests that the sequence variability of N-protein is mirrored by high plasticity of N-protein biophysical properties, which we hypothesize can be exploited by SARS-CoV-2 to achieve greater efficiency of viral assembly, and thereby enhanced infectivity.
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Affiliation(s)
- Huaying Zhao
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ai Nguyen
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Di Wu
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sergio A. Hassan
- Bioinformatics and Computational Biosciences Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jiji Chen
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hari Shroff
- Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Grzegorz Piszczek
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter Schuck
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
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19
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Ghosh K. Stoichiometric versus stochastic interaction in models of liquid-liquid phase separation. Biophys J 2022; 121:4-6. [PMID: 34932937 PMCID: PMC8758413 DOI: 10.1016/j.bpj.2021.12.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/01/2021] [Accepted: 12/06/2021] [Indexed: 01/07/2023] Open
Affiliation(s)
- Kingshuk Ghosh
- Department of Physics and Astronomy, University of Denver, Denver,Molecular and Cellular Biophysics, University of Denver, Denver,Corresponding author
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