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Chen X, Seyboldt R, Sommer JU, Jülicher F, Harmon T. Droplet Differentiation by a Chemical Switch. PHYSICAL REVIEW LETTERS 2024; 133:028402. [PMID: 39073969 DOI: 10.1103/physrevlett.133.028402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 05/29/2024] [Indexed: 07/31/2024]
Abstract
A fundamental question about biomolecular condensates is how distinct condensates can emerge from the interplay of different components. Here we present a minimal model of droplet differentiation where phase separated droplets demix into two types with different chemical modifications triggered by enzymatic reactions. We use numerical solutions to Cahn-Hilliard equations with chemical reactions and an effective droplet model to reveal the switchlike behavior. Our work shows how condensate identities in cells could result from competing enzymatic actions.
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Affiliation(s)
| | | | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung, Institut Theorie der Polymere, 01069 Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
- Institute for Theoretical Physics, TU Dresden, Zellescher Weg 17, 01069 Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzerstrasse 38, 01187 Dresden, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
- Center for Systems Biology Dresden, 01307 Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
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2
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Häfner G, Müller M. Reaction-Driven Diffusiophoresis of Liquid Condensates: Potential Mechanisms for Intracellular Organization. ACS NANO 2024; 18:16530-16544. [PMID: 38875706 PMCID: PMC11223496 DOI: 10.1021/acsnano.3c12842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 05/18/2024] [Accepted: 05/24/2024] [Indexed: 06/16/2024]
Abstract
The cellular environment, characterized by its intricate composition and spatial organization, hosts a variety of organelles, ranging from membrane-bound ones to membraneless structures that are formed through liquid-liquid phase separation. Cells show precise control over the position of such condensates. We demonstrate that organelle movement in external concentration gradients, diffusiophoresis, is distinct from the one of colloids because fluxes can remain finite inside the liquid-phase droplets and movement of the latter arises from incompressibility. Within cellular domains diffusiophoresis naturally arises from biochemical reactions that are driven by a chemical fuel and produce waste. Simulations and analytical arguments within a minimal model of reaction-driven phase separation reveal that the directed movement stems from two contributions: Fuel and waste are refilled or extracted at the boundary, resulting in concentration gradients, which (i) induce product fluxes via incompressibility and (ii) result in an asymmetric forward reaction in the droplet's surroundings (as well as asymmetric backward reaction inside the droplet), thereby shifting the droplet's position. We show that the former contribution dominates and sets the direction of the movement, toward or away from fuel source and waste sink, depending on the product molecules' affinity toward fuel and waste, respectively. The mechanism thus provides a simple means to organize condensates with different composition. Particle-based simulations and systems with more complex reaction cycles corroborate the robustness and universality of this mechanism.
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Affiliation(s)
- Gregor Häfner
- Georg-August
Universität Göttingen, Institut für Theoretische Physik, Friedrich-Hund Platz 1, 37077 Göttingen, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| | - Marcus Müller
- Georg-August
Universität Göttingen, Institut für Theoretische Physik, Friedrich-Hund Platz 1, 37077 Göttingen, Germany
- Max
Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
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3
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Rios MU, Bagnucka MA, Ryder BD, Ferreira Gomes B, Familiari NE, Yaguchi K, Amato M, Stachera WE, Joachimiak ŁA, Woodruff JB. Multivalent coiled-coil interactions enable full-scale centrosome assembly and strength. J Cell Biol 2024; 223:e202306142. [PMID: 38456967 PMCID: PMC10921949 DOI: 10.1083/jcb.202306142] [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: 06/29/2023] [Revised: 11/29/2023] [Accepted: 01/19/2024] [Indexed: 03/09/2024] Open
Abstract
The outermost layer of centrosomes, called pericentriolar material (PCM), organizes microtubules for mitotic spindle assembly. The molecular interactions that enable PCM to assemble and resist external forces are poorly understood. Here, we use crosslinking mass spectrometry (XL-MS) to analyze PLK-1-potentiated multimerization of SPD-5, the main PCM scaffold protein in C. elegans. In the unassembled state, SPD-5 exhibits numerous intramolecular crosslinks that are eliminated after phosphorylation by PLK-1. Thus, phosphorylation induces a structural opening of SPD-5 that primes it for assembly. Multimerization of SPD-5 is driven by interactions between multiple dispersed coiled-coil domains. Structural analyses of a phosphorylated region (PReM) in SPD-5 revealed a helical hairpin that dimerizes to form a tetrameric coiled-coil. Mutations within this structure and other interacting regions cause PCM assembly defects that are partly rescued by eliminating microtubule-mediated forces, revealing that PCM assembly and strength are interdependent. We propose that PCM size and strength emerge from specific, multivalent coiled-coil interactions between SPD-5 proteins.
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Affiliation(s)
- Manolo U. Rios
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Małgorzata A. Bagnucka
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bryan D. Ryder
- Department of Biochemistry, Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Nicole E. Familiari
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kan Yaguchi
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Matthew Amato
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weronika E. Stachera
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Łukasz A. Joachimiak
- Department of Biochemistry, Center for Alzheimer’s and Neurodegenerative Diseases, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey B. Woodruff
- Department of Cell Biology, Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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4
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Ramirez DA, Hough LE, Shirts MR. Coiled-coil domains are sufficient to drive liquid-liquid phase separation in protein models. Biophys J 2024; 123:703-717. [PMID: 38356260 PMCID: PMC10995412 DOI: 10.1016/j.bpj.2024.02.007] [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: 07/25/2023] [Revised: 12/09/2023] [Accepted: 02/09/2024] [Indexed: 02/16/2024] Open
Abstract
Liquid-liquid phase separation (LLPS) is thought to be a main driving force in the formation of membraneless organelles. Examples of such organelles include the centrosome, central spindle, and stress granules. Recently, it has been shown that coiled-coil (CC) proteins, such as the centrosomal proteins pericentrin, spd-5, and centrosomin, might be capable of LLPS. CC domains have physical features that could make them the drivers of LLPS, but it is unknown if they play a direct role in the process. We developed a coarse-grained simulation framework for investigating the LLPS propensity of CC proteins, in which interactions that support LLPS arise solely from CC domains. We show, using this framework, that the physical features of CC domains are sufficient to drive LLPS of proteins. The framework is specifically designed to investigate how the number of CC domains, as well as the multimerization state of CC domains, can affect LLPS. We show that small model proteins with as few as two CC domains can phase separate. Increasing the number of CC domains up to four per protein can somewhat increase LLPS propensity. We demonstrate that trimer-forming and tetramer-forming CC domains have a dramatically higher LLPS propensity than dimer-forming coils, which shows that multimerization state has a greater effect on LLPS than the number of CC domains per protein. These data support the hypothesis of CC domains as drivers of protein LLPS, and have implications in future studies to identify the LLPS-driving regions of centrosomal and central spindle proteins.
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Affiliation(s)
- Dominique A Ramirez
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado
| | - Loren E Hough
- Department of Physics and BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado
| | - Michael R Shirts
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado.
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5
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Sebtosheikh M, Naji A. Active osmoticlike pressure on permeable inclusions. Phys Rev E 2024; 109:034607. [PMID: 38632760 DOI: 10.1103/physreve.109.034607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 02/14/2024] [Indexed: 04/19/2024]
Abstract
We use a standard minimal active Brownian model to investigate the osmotic-like effective pressure generated by active fluids on fixed hollow inclusions. These inclusions are enclosed by a permeable (albeit nonflexible) membrane, and the interior and exterior regions of the inclusions have different particle motility strengths. We consider both rectangular and disklike inclusions and analyze the effects of various system parameters, such as excluded volume interaction between active particles, hardness of membrane, and active particle density, on the effective pressure produced on the enclosing membrane. We focus on the range of intermediate to high motility strengths and analyze the effective pressure in the steady state. Our findings for the active pressure produced in the interior and exterior regions of the inclusion indicate that the pressure is higher in the region with lower motility due to the relatively stronger accumulation of active particles.
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Affiliation(s)
- Mahmoud Sebtosheikh
- School of Nano Science, Institute for Research in Fundamental Sciences (IPM), Tehran 19538-33511, Iran
- School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran 19538-33511, Iran
| | - Ali Naji
- School of Nano Science, Institute for Research in Fundamental Sciences (IPM), Tehran 19538-33511, Iran
- Department of Physics, College of Science, Sultan Qaboos University, Muscat 123, Oman
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6
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Sárkány Z, Figueiredo F, Macedo-Ribeiro S, Martins PM. NAGPKin: Nucleation-and-growth parameters from the kinetics of protein phase separation. Mol Biol Cell 2024; 35:mr1. [PMID: 38117593 PMCID: PMC10916857 DOI: 10.1091/mbc.e23-07-0289] [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: 08/07/2023] [Revised: 11/27/2023] [Accepted: 12/13/2023] [Indexed: 12/22/2023] Open
Abstract
The assembly of biomolecular condensate in eukaryotic cells and the accumulation of amyloid deposits in neurons are processes involving the nucleation and growth (NAG) of new protein phases. To therapeutically target protein phase separation, drug candidates are tested in in vitro assays that monitor the increase in the mass or size of the new phase. Limited mechanistic insight is, however, provided if empirical or untestable kinetic models are fitted to these progress curves. Here we present the web server NAGPKin that quantifies NAG rates using mass-based or size-based progress curves as the input data. A report is generated containing the fitted NAG parameters and elucidating the phase separation mechanisms at play. The NAG parameters can be used to predict particle size distributions of, for example, protein droplets formed by liquid-liquid phase separation (LLPS) or amyloid fibrils formed by protein aggregation. Because minimal intervention is required from the user, NAGPKin is a good platform for standardized reporting of LLPS and protein self-assembly data. NAGPKin is useful for drug discovery as well as for fundamental studies on protein phase separation. NAGPKin is freely available (no login required) at https://nagpkin.i3s.up.pt.
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Affiliation(s)
- Zsuzsa Sárkány
- Biomolecular Structure and Function Group, IBMC – Instituto de Biologia Molecular e Celular, Porto 4200-135, Portugal
- i3S – Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto 4200-135, Portugal
| | - Francisco Figueiredo
- Biomolecular Structure and Function Group, IBMC – Instituto de Biologia Molecular e Celular, Porto 4200-135, Portugal
- i3S – Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto 4200-135, Portugal
| | - Sandra Macedo-Ribeiro
- Biomolecular Structure and Function Group, IBMC – Instituto de Biologia Molecular e Celular, Porto 4200-135, Portugal
- i3S – Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto 4200-135, Portugal
| | - Pedro M. Martins
- Biomolecular Structure and Function Group, IBMC – Instituto de Biologia Molecular e Celular, Porto 4200-135, Portugal
- i3S – Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Porto 4200-135, Portugal
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7
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Yan X, Zhang M, Wang D. Interplay between posttranslational modifications and liquid‒liquid phase separation in tumors. Cancer Lett 2024; 584:216614. [PMID: 38246226 DOI: 10.1016/j.canlet.2024.216614] [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: 11/08/2023] [Revised: 12/22/2023] [Accepted: 12/30/2023] [Indexed: 01/23/2024]
Abstract
Liquid‒liquid phase separation (LLPS) is a general phenomenon recently recognized to be critically involved in the regulation of a variety of cellular biological processes, such as transcriptional regulation, heterochromatin formation and signal transduction, through the compartmentalization of proteins or nucleic acids into droplet-like condensates. These processes are directly or indirectly related to tumor initiation and treatment. Posttranslational modifications (PTMs), which represent a rapid and reversible mechanism involved in the functional regulation of proteins, have emerged as key events in modulating LLPS under physiological or pathophysiological conditions, including tumorigenesis and antitumor therapy. In this review, we introduce the biological functions participated in cancer-associated LLPS, discuss the potential roles of LLPS during tumor onset or therapy, and emphasize the mechanistic characteristics of LLPS regulated by PTMs and its effects on tumor progression. We then provide a perspective on further studies on LLPS and its regulation by PTMs in cancer research. This review aims to broaden the understanding of the functions of LLPS and its regulation by PTMs under normal or aberrant cellular conditions.
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Affiliation(s)
- Xiaojun Yan
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
| | - Meng Zhang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China
| | - Donglai Wang
- State Key Laboratory of Common Mechanism Research for Major Diseases & Department of Medical Genetics, Institute of Basic Medical Sciences & School of Basic Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100005, China.
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8
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Wong SS, Wainman A, Saurya S, Raff JW. Regulation of centrosome size by the cell-cycle oscillator in Drosophila embryos. EMBO J 2024; 43:414-436. [PMID: 38233576 PMCID: PMC10898259 DOI: 10.1038/s44318-023-00022-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 01/19/2024] Open
Abstract
Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. In early C. elegans embryos, mitotic centrosome size appears to be set by the limiting amount of a key component. In Drosophila syncytial embryos, thousands of mitotic centrosomes are assembled as the embryo proceeds through 13 rounds of rapid nuclear division, driven by a core cell cycle oscillator. These divisions slow during nuclear cycles 11-13, and we find that centrosomes respond by reciprocally decreasing their growth rate, but increasing their growth period-so that they grow to a relatively consistent size at each cycle. At the start of each cycle, moderate CCO activity initially promotes centrosome growth, in part by stimulating Polo/PLK1 recruitment to centrosomes. Later in each cycle, high CCO activity inhibits centrosome growth by suppressing the centrosomal recruitment and/or maintenance of centrosome proteins. Thus, in fly embryos, mitotic centrosome size appears to be regulated predominantly by the core cell cycle oscillator, rather than by the depletion of a limiting component.
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Affiliation(s)
- Siu-Shing Wong
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Alan Wainman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Saroj Saurya
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Jordan W Raff
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK.
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9
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Gorsheneva NA, Sopova JV, Azarov VV, Grizel AV, Rubel AA. Biomolecular Condensates: Structure, Functions, Methods of Research. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:S205-S223. [PMID: 38621751 DOI: 10.1134/s0006297924140116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 04/17/2024]
Abstract
The term "biomolecular condensates" is used to describe membraneless compartments in eukaryotic cells, accumulating proteins and nucleic acids. Biomolecular condensates are formed as a result of liquid-liquid phase separation (LLPS). Often, they demonstrate properties of liquid-like droplets or gel-like aggregates; however, some of them may appear to have a more complex structure and high-order organization. Membraneless microcompartments are involved in diverse processes both in cytoplasm and in nucleus, among them ribosome biogenesis, regulation of gene expression, cell signaling, and stress response. Condensates properties and structure could be highly dynamic and are affected by various internal and external factors, e.g., concentration and interactions of components, solution temperature, pH, osmolarity, etc. In this review, we discuss variety of biomolecular condensates and their functions in live cells, describe their structure variants, highlight domain and primary sequence organization of the constituent proteins and nucleic acids. Finally, we describe current advances in methods that characterize structure, properties, morphology, and dynamics of biomolecular condensates in vitro and in vivo.
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Affiliation(s)
| | - Julia V Sopova
- St. Petersburg State University, St. Petersburg, 199034, Russia.
| | | | - Anastasia V Grizel
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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10
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Alston H, Cocconi L, Bertrand T. Irreversibility across a Nonreciprocal PT-Symmetry-Breaking Phase Transition. PHYSICAL REVIEW LETTERS 2023; 131:258301. [PMID: 38181344 DOI: 10.1103/physrevlett.131.258301] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 10/30/2023] [Indexed: 01/07/2024]
Abstract
Nonreciprocal interactions are commonplace in continuum-level descriptions of both biological and synthetic active matter, yet studies addressing their implications for time reversibility have so far been limited to microscopic models. Here, we derive a general expression for the average rate of informational entropy production in the most generic mixture of conserved phase fields with nonreciprocal couplings and additive conservative noise. For the particular case of a binary system with Cahn-Hilliard dynamics augmented by nonreciprocal cross-diffusion terms, we observe a nontrivial scaling of the entropy production rate across a parity-time symmetry breaking phase transition. We derive a closed-form analytic expression in the weak-noise regime for the entropy production rate due to the emergence of a macroscopic dynamic phase, showing it can be written in terms of the global polar order parameter, a measure of parity-time symmetry breaking.
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Affiliation(s)
- Henry Alston
- Department of Mathematics, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Luca Cocconi
- Department of Mathematics, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
- The Francis Crick Institute, London NW1 1AT, United Kingdom
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Thibault Bertrand
- Department of Mathematics, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
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11
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Gao G, Sumrall ES, Pitchiaya S, Bitzer M, Alberti S, Walter NG. Biomolecular condensates in kidney physiology and disease. Nat Rev Nephrol 2023; 19:756-770. [PMID: 37752323 DOI: 10.1038/s41581-023-00767-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2023] [Indexed: 09/28/2023]
Abstract
The regulation and preservation of distinct intracellular and extracellular solute microenvironments is crucial for the maintenance of cellular homeostasis. In mammals, the kidneys control bodily salt and water homeostasis. Specifically, the urine-concentrating mechanism within the renal medulla causes fluctuations in extracellular osmolarity, which enables cells of the kidney to either conserve or eliminate water and electrolytes, depending on the balance between intake and loss. However, relatively little is known about the subcellular and molecular changes caused by such osmotic stresses. Advances have shown that many cells, including those of the kidney, rapidly (within seconds) and reversibly (within minutes) assemble membraneless, nano-to-microscale subcellular assemblies termed biomolecular condensates via the biophysical process of hyperosmotic phase separation (HOPS). Mechanistically, osmotic cell compression mediates changes in intracellular hydration, concentration and molecular crowding, rendering HOPS one of many related phase-separation phenomena. Osmotic stress causes numerous homo-multimeric proteins to condense, thereby affecting gene expression and cell survival. HOPS rapidly regulates specific cellular biochemical processes before appropriate protective or corrective action by broader stress response mechanisms can be initiated. Here, we broadly survey emerging evidence for, and the impact of, biomolecular condensates in nephrology, where initial concentration buffering by HOPS and its subsequent cellular escalation mechanisms are expected to have important implications for kidney physiology and disease.
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Affiliation(s)
- Guoming Gao
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | - Emily S Sumrall
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Markus Bitzer
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Simon Alberti
- Technische Universität Dresden, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Engineering (CMCB), Dresden, Germany
| | - Nils G Walter
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA.
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12
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Lee NK, Chae MK, Jung Y, Johner A, Joanny JF. Polyelectrolytes: From Seminal Works to the Influence of the Charge Sequence. Polymers (Basel) 2023; 15:4593. [PMID: 38232020 PMCID: PMC10708673 DOI: 10.3390/polym15234593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/19/2023] [Accepted: 11/27/2023] [Indexed: 01/19/2024] Open
Abstract
We propose a selected tour of the physics of polyelectrolytes (PE) following the line initiated by de Gennes and coworkers in their seminal 1976 paper. The early works which used uniform charge distributions along the PE backbone achieved tremendous progress and set most milestones in the field. Recently, the focus has shifted to the role of the charge sequence. Revisited topics include PE complexation and polyampholytes (PA). We develop the example of a random PE in poor solvent forming pearl-necklace structures. It is shown that the pearls typically adopt very asymmetric mass and charge distributions. Individual sequences do not necessarily reflect the ensemble statistics and a rich variety of behaviors emerges (specially for PA). Pearl necklaces are dynamic structures and switch between various types of pearl-necklace structures, as described for both PE and PA.
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Affiliation(s)
- Nam-Kyung Lee
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Republic of Korea;
| | - Min-Kyung Chae
- National Institute for Mathematical Sciences, Daejeon 34047, Republic of Korea;
| | - Youngkyun Jung
- Supercomputing Center, Korea Institute of Science and Technology Information, Daejeon 34141, Republic of Korea;
| | - Albert Johner
- Institut Charles Sadron CNRS-Unistra, 6 rue Boussingault, 67083 Strasbourg, France
| | - Jean-Francois Joanny
- Institut Curie, Physique des cellules et Cancer, Collège de France Soft Matter and Biophysics Chair, 11, PSL University, Place Marcelin-Berthelot, 75231 Paris, France;
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13
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Osmanović D, Franco E. Chemical reaction motifs driving non-equilibrium behaviours in phase separating materials. J R Soc Interface 2023; 20:20230117. [PMID: 37907095 PMCID: PMC10618056 DOI: 10.1098/rsif.2023.0117] [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: 03/02/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023] Open
Abstract
Chemical reactions that couple to systems that phase separate have been implicated in diverse contexts from biology to materials science. However, how a particular set of chemical reactions (chemical reaction network, CRN) would affect the behaviours of a phase separating system is difficult to fully predict theoretically. In this paper, we analyse a mean field theory coupling CRNs to a combined system of phase separating and non-phase separating materials and analyse how the properties of the CRNs affect different classes of non-equilibrium behaviour: microphase separation or temporally oscillating patterns. We examine the problem of achieving microphase separated condensates by statistical analysis of the Jacobians, of which the most important motifs are negative feedback of the phase separating component and combined inhibition/activation by the non-phase separating components. We then identify CRN motifs that are likely to yield microphase by examining randomly generated networks and parameters. Molecular sequestration of the phase separating motif is shown to be the most robust towards yielding microphase separation. Subsequently, we find that dynamics of the phase separating species is promoted most easily by inducing oscillations in the diffusive components coupled to the phase separating species. Our results provide guidance towards the design of CRNs that manage the formation, dissolution and organization of compartments.
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Affiliation(s)
- Dino Osmanović
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles 90095, CA, USA
| | - Elisa Franco
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles 90095, CA, USA
- Department of Bioengineering, University of California, Los Angeles 90095, CA, USA
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14
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Ader NR, Chen L, Surovtsev IV, Chadwick WL, Rodriguez EC, King MC, Lusk CP. An ESCRT grommet cooperates with a diffusion barrier to maintain nuclear integrity. Nat Cell Biol 2023; 25:1465-1477. [PMID: 37783794 DOI: 10.1038/s41556-023-01235-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 08/17/2023] [Indexed: 10/04/2023]
Abstract
The molecular mechanisms by which the endosomal sorting complexes required for transport (ESCRT) proteins contribute to the integrity of the nuclear envelope (NE) barrier are not fully defined. We leveraged the single NE hole generated by mitotic extrusion of the Schizosaccharomyces pombe spindle pole body to reveal two modes of ESCRT function executed by distinct complements of ESCRT-III proteins, both dependent on CHMP7/Cmp7. A grommet-like function is required to restrict the NE hole in anaphase B, whereas replacement of Cmp7 by a sealing module ultimately closes the NE in interphase. Without Cmp7, nucleocytoplasmic compartmentalization remains intact despite NE discontinuities of up to 540 nm, suggesting mechanisms to limit diffusion through these holes. We implicate spindle pole body proteins as key components of a diffusion barrier acting with Cmp7 in anaphase B. Thus, NE remodelling mechanisms cooperate with proteinaceous diffusion barriers beyond nuclear pore complexes to maintain the nuclear compartment.
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Affiliation(s)
- Nicholas R Ader
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - Linda Chen
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - Ivan V Surovtsev
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
- Department of Physics, Yale University, New Haven, CT, USA
| | | | - Elisa C Rodriguez
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - Megan C King
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA.
- Department of Molecular, Cell and Developmental Biology, Yale University, New Haven, CT, USA.
| | - C Patrick Lusk
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA.
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15
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Tschurikow X, Gadzekpo A, Tran MP, Chatterjee R, Sobucki M, Zaburdaev V, Göpfrich K, Hilbert L. Amphiphiles Formed from Synthetic DNA-Nanomotifs Mimic the Stepwise Dispersal of Transcriptional Clusters in the Cell Nucleus. NANO LETTERS 2023; 23:7815-7824. [PMID: 37586706 PMCID: PMC10510709 DOI: 10.1021/acs.nanolett.3c01301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 07/28/2023] [Indexed: 08/18/2023]
Abstract
Stem cells exhibit prominent clusters controlling the transcription of genes into RNA. These clusters form by a phase-separation mechanism, and their size and shape are controlled via an amphiphilic effect of transcribed genes. Here, we construct amphiphile-nanomotifs purely from DNA, and we achieve similar size and shape control for phase-separated droplets formed from fully synthetic, self-interacting DNA-nanomotifs. Increasing amphiphile concentrations induce rounding of droplets, prevent droplet fusion, and, at high concentrations, cause full dispersal of droplets. Super-resolution microscopy data obtained from zebrafish embryo stem cells reveal a comparable transition for transcriptional clusters with increasing transcription levels. Brownian dynamics and lattice simulations further confirm that the addition of amphiphilic particles is sufficient to explain the observed changes in shape and size. Our work reproduces key aspects of transcriptional cluster formation in biological cells using relatively simple DNA sequence-programmable nanostructures, opening novel ways to control the mesoscopic organization of synthetic nanomaterials.
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Affiliation(s)
- Xenia Tschurikow
- Institute
of Biological and Chemical Systems, Karlsruhe
Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
- Zoological
Institute, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany
| | - Aaron Gadzekpo
- Institute
of Biological and Chemical Systems, Karlsruhe
Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
- Zoological
Institute, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany
| | - Mai P. Tran
- Center
for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
- Max
Planck Institute for Medical Research, Heidelberg 69120, Germany
| | - Rakesh Chatterjee
- Max
Planck Zentrum für Physik und Medizin, Erlangen 91058, Germany
- Chair
of Mathematics in Life Sciences, Friedrich-Alexander
Universität Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Marcel Sobucki
- Institute
of Biological and Chemical Systems, Karlsruhe
Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
| | - Vasily Zaburdaev
- Max
Planck Zentrum für Physik und Medizin, Erlangen 91058, Germany
- Chair
of Mathematics in Life Sciences, Friedrich-Alexander
Universität Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Kerstin Göpfrich
- Center
for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
- Max
Planck Institute for Medical Research, Heidelberg 69120, Germany
| | - Lennart Hilbert
- Institute
of Biological and Chemical Systems, Karlsruhe
Institute of Technology, Eggenstein-Leopoldshafen 76344, Germany
- Zoological
Institute, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany
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16
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Banerjee DS, Banerjee S. Catalytic growth in a shared enzyme pool ensures robust control of centrosome size. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.06.543875. [PMID: 37333186 PMCID: PMC10274694 DOI: 10.1101/2023.06.06.543875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Accurate regulation of centrosome size is essential for ensuring error-free cell division, and dysregulation of centrosome size has been linked to various pathologies, including developmental defects and cancer. While a universally accepted model for centrosome size regulation is lacking, prior theoretical and experimental work suggest a centrosome growth model involving autocatalytic assembly of the pericentriolic material. Here we show that the autocatalytic assembly model fails to explain the attainment of equal centrosome sizes, which is crucial for error-free cell division. Incorporating latest experimental findings into the molecular mechanisms governing centrosome assembly, we introduce a new quantitative theory for centrosome growth involving catalytic assembly within a shared pool of enzymes. Our model successfully achieves robust size equality between maturing centrosome pairs, mirroring cooperative growth dynamics observed in experiments. To validate our theoretical predictions, we compare them with available experimental data and demonstrate the broad applicability of the catalytic growth model across different organisms, which exhibit distinct growth dynamics and size scaling characteristics.
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Affiliation(s)
- Deb Sankar Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Shiladitya Banerjee
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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17
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Sárkány Z, Rocha F, Bratek‐Skicki A, Tompa P, Macedo‐Ribeiro S, Martins PM. Quantification of Surface Tension Effects and Nucleation-and-Growth Rates during Self-Assembly of Biological Condensates. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301501. [PMID: 37279376 PMCID: PMC10427409 DOI: 10.1002/advs.202301501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/12/2023] [Indexed: 06/08/2023]
Abstract
Liquid-solid and liquid-liquid phase separation (PS) drives the formation of functional and disease-associated biological assemblies. Principles of phase equilibrium are here employed to derive a general kinetic solution that predicts the evolution of the mass and size of biological assemblies. Thermodynamically, protein PS is determined by two measurable concentration limits: the saturation concentration and the critical solubility. Due to surface tension effects, the critical solubility can be higher than the saturation concentration for small, curved nuclei. Kinetically, PS is characterized by the primary nucleation rate constant and a combined rate constant accounting for growth and secondary nucleation. It is demonstrated that the formation of a limited number of large condensates is possible without active mechanisms of size control and in the absence of coalescence phenomena. The exact analytical solution can be used to interrogate how the elementary steps of PS are affected by candidate drugs.
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Affiliation(s)
- Zsuzsa Sárkány
- IBMC − Instituto de Biologia Molecular e CelularUniversidade do PortoPorto4150–180Portugal
- i3S − Instituto de Investigação e Inovação em SaúdeUniversidade do PortoPorto4150–180Portugal
| | - Fernando Rocha
- LEPABE − Laboratory for Process Engineering Environment Biotechnology and EnergyFaculdade de Engenharia da Universidade do PortoPorto4200‐465Portugal
| | - Anna Bratek‐Skicki
- Jerzy Haber Institute of Catalysis and Surface ChemistryPolish Academy of SciencesNiezapominajek 8KrakowPL30239Poland
- VIB‐VUB Center for Structural BiologyVlaams Instituut voor BiotechnologyBrussels1050 IxellesBelgium
- Structural Biology Brussels (SBB)Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsB‐1050Belgium
| | - Peter Tompa
- VIB‐VUB Center for Structural BiologyVlaams Instituut voor BiotechnologyBrussels1050 IxellesBelgium
- Structural Biology Brussels (SBB)Bioengineering Sciences DepartmentVrije Universiteit Brussel (VUB)BrusselsB‐1050Belgium
- Institute of EnzymologyResearch Centre for Natural SciencesBudapest1117Hungary
| | - Sandra Macedo‐Ribeiro
- IBMC − Instituto de Biologia Molecular e CelularUniversidade do PortoPorto4150–180Portugal
- i3S − Instituto de Investigação e Inovação em SaúdeUniversidade do PortoPorto4150–180Portugal
| | - Pedro M. Martins
- IBMC − Instituto de Biologia Molecular e CelularUniversidade do PortoPorto4150–180Portugal
- i3S − Instituto de Investigação e Inovação em SaúdeUniversidade do PortoPorto4150–180Portugal
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18
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Ramirez DA, Hough LE, Shirts MR. Coiled-coil domains are sufficient to drive liquid-liquid phase separation of proteins in molecular models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543124. [PMID: 37398035 PMCID: PMC10312653 DOI: 10.1101/2023.05.31.543124] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Liquid-liquid phase separation (LLPS) is thought to be a main driving force in the formation of membraneless organelles. Examples of such organelles include the centrosome, central spindle, and stress granules. Recently, it has been shown that coiled-coil (CC) proteins, such as the centrosomal proteins pericentrin, spd-5, and centrosomin, might be capable of LLPS. CC domains have physical features that could make them the drivers of LLPS, but it is unknown if they play a direct role in the process. We developed a coarse-grained simulation framework for investigating the LLPS propensity of CC proteins, in which interactions which support LLPS arise solely from CC domains. We show, using this framework, that the physical features of CC domains are sufficient to drive LLPS of proteins. The framework is specifically designed to investigate how the number of CC domains, as well as multimerization state of CC domains, can affect LLPS. We show that small model proteins with as few as two CC domains can phase separate. Increasing the number of CC domains up to four per protein can somewhat increase LLPS propensity. We demonstrate that trimer-forming and tetramer-forming CC domains have a dramatically higher LLPS propensity than dimer-forming coils, which shows that multimerization state has a greater effect on LLPS than the number of CC domains per protein. These data support the hypothesis of CC domains as drivers of protein LLPS, and has implications in future studies to identify the LLPS-driving regions of centrosomal and central spindle proteins.
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Affiliation(s)
| | - Loren E. Hough
- Department of Physics and BioFrontiers Institute, University of Colorado Boulder, Boulder CO, 80309
| | - Michael R. Shirts
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder CO, 80309
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19
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Durinova E, Mojzes P, Bily T, Franta Z, Fessl T, Borodavka A, Tuma R. Shedding light on reovirus assembly-Multimodal imaging of viral factories. Adv Virus Res 2023; 116:173-213. [PMID: 37524481 DOI: 10.1016/bs.aivir.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Avian (ortho)reovirus (ARV), which belongs to Reoviridae family, is a major domestic fowl pathogen and is the causative agent of viral tenosynovitis and chronic respiratory disease in chicken. ARV replicates within cytoplasmic inclusions, so-called viral factories, that form by phase separation and thus belong to a wider class of biological condensates. Here, we evaluate different optical imaging methods that have been developed or adapted to follow formation, fluidity and composition of viral factories and compare them with the complementary structural information obtained by well-established transmission electron microscopy and electron tomography. The molecular and cellular biology aspects for setting up and following virus infection in cells by imaging are described first. We then demonstrate that a wide-field version of fluorescence recovery after photobleaching is an effective tool to measure fluidity of mobile viral factories. A new technique, holotomographic phase microscopy, is then used for imaging of viral factory formation in live cells in three dimensions. Confocal Raman microscopy of infected cells provides "chemical" contrast for label-free segmentation of images and addresses important questions about biomolecular concentrations within viral factories and other biological condensates. Optical imaging is complemented by electron microscopy and tomography which supply higher resolution structural detail, including visualization of individual virions within the three-dimensional cellular context.
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Affiliation(s)
- Eva Durinova
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic; Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Peter Mojzes
- Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Tomas Bily
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic; Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Zdenek Franta
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Tomas Fessl
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Roman Tuma
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic.
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20
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Ziethen N, Kirschbaum J, Zwicker D. Nucleation of Chemically Active Droplets. PHYSICAL REVIEW LETTERS 2023; 130:248201. [PMID: 37390433 DOI: 10.1103/physrevlett.130.248201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 05/10/2023] [Indexed: 07/02/2023]
Abstract
Driven chemical reactions can control the macroscopic properties of droplets, like their size. Such active droplets are critical in structuring the interior of biological cells. Cells also need to control where and when droplets appear, so they need to control droplet nucleation. Our numerical simulations demonstrate that reactions generally suppress nucleation if they stabilize the homogeneous state. An equilibrium surrogate model reveals that reactions increase the effective energy barrier of nucleation, enabling quantitative predictions of the increased nucleation times. Moreover, the surrogate model allows us to construct a phase diagram, which summarizes how reactions affect the stability of the homogeneous phase and the droplet state. This simple picture provides accurate predictions of how driven reactions delay nucleation, which is relevant for understanding droplets in biological cells and chemical engineering.
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Affiliation(s)
- Noah Ziethen
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17 37077, Göttingen, Germany
| | - Jan Kirschbaum
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17 37077, Göttingen, Germany
| | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17 37077, Göttingen, Germany
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21
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Modi N, Chen S, Adjei INA, Franco BL, Bishop KJM, Obermeyer AC. Designing negative feedback loops in enzymatic coacervate droplets. Chem Sci 2023; 14:4735-4744. [PMID: 37181760 PMCID: PMC10171067 DOI: 10.1039/d2sc03838b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 03/13/2023] [Indexed: 05/16/2023] Open
Abstract
Membraneless organelles within the living cell use phase separation of biomolecules coupled with enzymatic reactions to regulate cellular processes. The diverse functions of these biomolecular condensates motivate the pursuit of simpler in vitro models that exhibit primitive forms of self-regulation based on internal feedback mechanisms. Here, we investigate one such model based on complex coacervation of the enzyme catalase with an oppositely charge polyelectrolyte DEAE-dextran to form pH-responsive catalytic droplets. Upon addition of hydrogen peroxide "fuel", enzyme activity localized within the droplets causes a rapid increase in the pH. Under appropriate conditions, this reaction-induced pH change triggers coacervate dissolution owing to its pH-responsive phase behavior. Notably, this destabilizing effect of the enzymatic reaction on phase separation depends on droplet size owing to the diffusive delivery and removal of reaction components. Reaction-diffusion models informed by the experimental data show that larger drops support larger changes in the local pH thereby enhancing their dissolution relative to smaller droplets. Together, these results provide a basis for achieving droplet size control based on negative feedback between pH-dependent phase separation and pH-changing enzymatic reactions.
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Affiliation(s)
- Nisha Modi
- Department of Chemical Engineering, Columbia University New York USA
| | - Siwei Chen
- Department of Chemical Engineering, Columbia University New York USA
| | - Imelda N A Adjei
- Department of Biomedical Engineering, Columbia University New York USA
| | - Briana L Franco
- Department of Chemical Engineering, Columbia University New York USA
| | - Kyle J M Bishop
- Department of Chemical Engineering, Columbia University New York USA
| | - Allie C Obermeyer
- Department of Chemical Engineering, Columbia University New York USA
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22
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Hagan MF, Mohajerani F. Self-assembly coupled to liquid-liquid phase separation. PLoS Comput Biol 2023; 19:e1010652. [PMID: 37186597 PMCID: PMC10212142 DOI: 10.1371/journal.pcbi.1010652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 05/25/2023] [Accepted: 04/26/2023] [Indexed: 05/17/2023] Open
Abstract
Liquid condensate droplets with distinct compositions of proteins and nucleic acids are widespread in biological cells. While it is known that such droplets, or compartments, can regulate irreversible protein aggregation, their effect on reversible self-assembly remains largely unexplored. In this article, we use kinetic theory and solution thermodynamics to investigate the effect of liquid-liquid phase separation on the reversible self-assembly of structures with well-defined sizes and architectures. We find that, when assembling subunits preferentially partition into liquid compartments, robustness against kinetic traps and maximum achievable assembly rates can be significantly increased. In particular, both the range of solution conditions leading to productive assembly and the corresponding assembly rates can increase by orders of magnitude. We analyze the rate equation predictions using simple scaling estimates to identify effects of liquid-liquid phase separation as a function of relevant control parameters. These results may elucidate self-assembly processes that underlie normal cellular functions or pathogenesis, and suggest strategies for designing efficient bottom-up assembly for nanomaterials applications.
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Affiliation(s)
- Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
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23
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Liu Z, Yethiraj A, Cui Q. Sensitive and selective polymer condensation at membrane surface driven by positive co-operativity. Proc Natl Acad Sci U S A 2023; 120:e2212516120. [PMID: 37018196 PMCID: PMC10104518 DOI: 10.1073/pnas.2212516120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 03/06/2023] [Indexed: 04/06/2023] Open
Abstract
Biomolecular phase separation has emerged as an essential mechanism for cellular organization. How cells respond to environmental stimuli in a robust and sensitive manner to build functional condensates at the proper time and location is only starting to be understood. Recently, lipid membranes have been recognized as an important regulatory center for biomolecular condensation. However, how the interplay between the phase behaviors of cellular membranes and surface biopolymers may contribute to the regulation of surface condensation remains to be elucidated. Using simulations and a mean-field theoretical model, we show that two key factors are the membrane's tendency to phase-separate and the surface polymer's ability to reorganize local membrane composition. Surface condensate forms with high sensitivity and selectivity in response to features of biopolymer when positive co-operativity is established between coupled growth of the condensate and local lipid domains. This effect relating the degree of membrane-surface polymer co-operativity and condensate property regulation is shown to be robust by different ways of tuning the co-operativity, such as varying membrane protein obstacle concentration, lipid composition, and the affinity between lipid and polymer. The general physical principle emerged from the current analysis may have implications in other biological processes and beyond.
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Affiliation(s)
- Zhuang Liu
- Department of Physics, Boston University, Boston, MA02215
| | - Arun Yethiraj
- Department of Chemistry, University of Wisconsin, Madison, WI53706
| | - Qiang Cui
- Department of Physics, Boston University, Boston, MA02215
- Department of Chemistry, Boston University, Boston, MA02215
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24
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Maheshwari R, Rahman MM, Drey S, Onyundo M, Fabig G, Martinez MAQ, Matus DQ, Müller-Reichert T, Cohen-Fix O. A membrane reticulum, the centriculum, affects centrosome size and function in Caenorhabditis elegans. Curr Biol 2023; 33:791-806.e7. [PMID: 36693370 PMCID: PMC10023444 DOI: 10.1016/j.cub.2022.12.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/21/2022] [Accepted: 12/21/2022] [Indexed: 01/24/2023]
Abstract
Centrosomes are cellular structures that nucleate microtubules. At their core is a pair of centrioles that recruit pericentriolar material (PCM). Although centrosomes are considered membraneless organelles, in many cell types, including human cells, centrosomes are surrounded by endoplasmic reticulum (ER)-derived membranes of unknown structure and function. Using volume electron microscopy (vEM), we show that centrosomes in the Caenorhabditis elegans (C. elegans) early embryo are surrounded by a three-dimensional (3D), ER-derived membrane reticulum that we call the centriculum, for centrosome-associated membrane reticulum. The centriculum is adjacent to the nuclear envelope in interphase and early mitosis and fuses with the fenestrated nuclear membrane at metaphase. Centriculum formation is dependent on the presence of an underlying centrosome and on microtubules. Conversely, increasing centriculum size by genetic means led to the expansion of the PCM, increased microtubule nucleation capacity, and altered spindle width. The effect of the centriculum on centrosome function suggests that in the C. elegans early embryo, the centrosome is not membraneless. Rather, it is encased in a membrane meshwork that affects its properties. We provide evidence that the centriculum serves as a microtubule "filter," preventing the elongation of a subset of microtubules past the centriculum. Finally, we propose that the fusion between the centriculum and the nuclear membrane contributes to nuclear envelope breakdown by coupling spindle elongation to nuclear membrane fenestration.
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Affiliation(s)
- Richa Maheshwari
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mohammad M Rahman
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Seth Drey
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Megan Onyundo
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Orna Cohen-Fix
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA.
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25
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Kulkarni A, Vidal-Henriquez E, Zwicker D. Effective simulations of interacting active droplets. Sci Rep 2023; 13:733. [PMID: 36639416 PMCID: PMC9839783 DOI: 10.1038/s41598-023-27630-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 01/04/2023] [Indexed: 01/15/2023] Open
Abstract
Droplets form a cornerstone of the spatiotemporal organization of biomolecules in cells. These droplets are controlled using physical processes like chemical reactions and imposed gradients, which are costly to simulate using traditional approaches, like solving the Cahn-Hilliard equation. To overcome this challenge, we here present an alternative, efficient method. The main idea is to focus on the relevant degrees of freedom, like droplet positions and sizes. We derive dynamical equations for these quantities using approximate analytical solutions obtained from a sharp interface limit and linearized equations in the bulk phases. We verify our method against fully-resolved simulations and show that it can describe interacting droplets under the influence of chemical reactions and external gradients using only a fraction of the computational costs of traditional methods. Our method can be extended to include other processes in the future and will thus serve as a relevant platform for understanding the dynamics of droplets in cells.
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Affiliation(s)
- Ajinkya Kulkarni
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077, Göttingen, Germany
| | | | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077, Göttingen, Germany.
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26
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Donau C, Boekhoven J. The chemistry of chemically fueled droplets. TRENDS IN CHEMISTRY 2022. [DOI: 10.1016/j.trechm.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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27
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Cheng H, Kao Y, Chen T, Sharma L, Yang W, Chuang Y, Huang S, Lin H, Huang Y, Kao C, Yang L, Bearon R, Cheng H, Hsia K, Lin Y. Actin filaments form a size-dependent diffusion barrier around centrosomes. EMBO Rep 2022; 24:e54935. [PMID: 36314725 PMCID: PMC9827556 DOI: 10.15252/embr.202254935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 09/29/2022] [Accepted: 10/11/2022] [Indexed: 01/10/2023] Open
Abstract
The centrosome, a non-membranous organelle, constrains various soluble molecules locally to execute its functions. As the centrosome is surrounded by various dense components, we hypothesized that it may be bordered by a putative diffusion barrier. After quantitatively measuring the trapping kinetics of soluble proteins of varying size at centrosomes by a chemically inducible diffusion trapping assay, we find that centrosomes are highly accessible to soluble molecules with a Stokes radius of less than 5.8 nm, whereas larger molecules rarely reach centrosomes, indicating the existence of a size-dependent diffusion barrier at centrosomes. The permeability of this barrier is tightly regulated by branched actin filaments outside of centrosomes and it decreases during anaphase when branched actin temporally increases. The actin-based diffusion barrier gates microtubule nucleation by interfering with γ-tubulin ring complex recruitment. We propose that actin filaments spatiotemporally constrain protein complexes at centrosomes in a size-dependent manner.
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Affiliation(s)
- Hsuan Cheng
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Yu‐Lin Kao
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Ting Chen
- Institute of Bioinformatics and Structural BiologyNational Tsing Hua UniversityHsinchuTaiwan
| | - Lohitaksh Sharma
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Wen‐Ting Yang
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Yi‐Chien Chuang
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Shih‐Han Huang
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Hong‐Rui Lin
- Institute of Bioinformatics and Structural BiologyNational Tsing Hua UniversityHsinchuTaiwan
| | - Yao‐Shen Huang
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Chi‐Ling Kao
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan
| | - Lee‐Wei Yang
- Institute of Bioinformatics and Structural BiologyNational Tsing Hua UniversityHsinchuTaiwan,Physics DivisionNational Center for Theoretical SciencesTaipeiTaiwan
| | - Rachel Bearon
- Department of Mathematical ScienceUniversity of LiverpoolLiverpoolUK
| | - Hui‐Chun Cheng
- Institute of Bioinformatics and Structural BiologyNational Tsing Hua UniversityHsinchuTaiwan
| | | | - Yu‐Chun Lin
- Institute of Molecular MedicineNational Tsing Hua UniversityHsinchuTaiwan,Department of Medical ScienceNational Tsing Hua UniversityHsinchuTaiwan
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28
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Nandi SK, Österle D, Heidenreich M, Levy ED, Safran SA. Affinity and Valence Impact the Extent and Symmetry of Phase Separation of Multivalent Proteins. PHYSICAL REVIEW LETTERS 2022; 129:128102. [PMID: 36179193 DOI: 10.1103/physrevlett.129.128102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 07/07/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Biomolecular self-assembly spatially segregates proteins with a limited number of binding sites (valence) into condensates that coexist with a dilute phase. We develop a many-body lattice model for a three-component system of proteins with fixed valence in a solvent. We compare the predictions of the model to experimental phase diagrams that we measure in vivo, which allows us to vary specifically a binding site's affinity and valency. We find that the extent of phase separation varies exponentially with affinity and increases with valency. Valency alone determines the symmetry of the phase diagram.
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Affiliation(s)
- Saroj Kumar Nandi
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
- Tata Institute of Fundamental Research, Hyderabad 500046, India
| | - Daniel Österle
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Meta Heidenreich
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Emmanuel D Levy
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Samuel A Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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29
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Alston H, Parry AO, Voituriez R, Bertrand T. Intermittent attractive interactions lead to microphase separation in nonmotile active matter. Phys Rev E 2022; 106:034603. [PMID: 36266896 DOI: 10.1103/physreve.106.034603] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 07/26/2022] [Indexed: 06/16/2023]
Abstract
Nonmotile active matter exhibits a wide range of nonequilibrium collective phenomena yet examples are crucially lacking in the literature. We present a microscopic model inspired by the bacteria Neisseria meningitidis in which diffusive agents feel intermittent attractive forces. Through a formal coarse-graining procedure, we show that this truly scalar model of active matter exhibits the time-reversal-symmetry breaking terms defining the Active Model B+ class. In particular, we confirm the presence of microphase separation by solving the kinetic equations numerically. We show that the switching rate controlling the interactions provides a regulation mechanism tuning the typical cluster size, e.g., in populations of bacteria interacting via type IV pili.
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Affiliation(s)
- Henry Alston
- Department of Mathematics, Imperial College London, 180 Queen's Gate, London SW7 2BZ, United Kingdom
| | - Andrew O Parry
- Department of Mathematics, Imperial College London, 180 Queen's Gate, London SW7 2BZ, United Kingdom
| | - Raphaël Voituriez
- Laboratoire de Physique Théorique de la Matière Condensée, UMR 7600 CNRS/UPMC, 4 Place Jussieu, 75255 Paris Cedex, France
- Laboratoire Jean Perrin, UMR 8237 CNRS/UPMC, 4 Place Jussieu, 75255 Paris Cedex, France
| | - Thibault Bertrand
- Department of Mathematics, Imperial College London, 180 Queen's Gate, London SW7 2BZ, United Kingdom
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30
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Murph M, Singh S, Schvarzstein M. A combined in silico and in vivo approach to the structure-function annotation of SPD-2 provides mechanistic insight into its functional diversity. Cell Cycle 2022; 21:1958-1979. [PMID: 35678569 PMCID: PMC9415446 DOI: 10.1080/15384101.2022.2078458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 04/10/2022] [Accepted: 05/04/2022] [Indexed: 11/03/2022] Open
Abstract
Centrosomes are organelles that function as hubs of microtubule nucleation and organization, with key roles in organelle positioning, asymmetric cell division, ciliogenesis, and signaling. Aberrant centrosome number, structure or function is linked to neurodegenerative diseases, developmental abnormalities, ciliopathies, and tumor development. A major regulator of centrosome biogenesis and function in C. elegans is the conserved Spindle-defective protein 2 (SPD-2), a homolog of the human CEP-192 protein. CeSPD-2 is required for centrosome maturation, centriole duplication, spindle assembly and possibly cell polarity establishment. Despite its importance, the specific molecular mechanism of CeSPD-2 regulation and function is poorly understood. Here, we combined computational analysis with cell biology approaches to uncover possible structure-function relationships of CeSPD-2 that may shed mechanistic light on its function. Domain prediction analysis corroborated and refined previously identified coiled-coils and ASH (Aspm-SPD-2 Hydin) domains and identified new domains: a GEF domain, an Ig-like domain, and a PDZ-like domain. In addition to these predicted structural features, CeSPD-2 is also predicted to be intrinsically disordered. Surface electrostatic maps identified a large basic region unique to the ASH domain of CeSPD-2. This basic region overlaps with most of the residues predicted to be involved in protein-protein interactions. In vivo, ASH::GFP localized to centrosomes and centrosome-associated microtubules. Our analysis groups ASH domains, PapD, Usher chaperone domains, and Major Sperm Protein (MSP) domains into a single superfold within the larger Immunoglobulin superfamily. This study lays the groundwork for designing rational hypothesis-based experiments to uncover the mechanisms of CeSPD-2 function in vivo.Abbreviations: AIR, Aurora kinase; ASH, Aspm-SPD-2 Hydin; ASP, Abnormal Spindle Protein; ASPM, Abnormal Spindle-like Microcephaly-associated Protein; CC, coiled-coil; CDK, Cyclin-dependent Kinase; Ce, Caenorhabditis elegans; CEP, Centrosomal Protein; CPAP, centrosomal P4.1-associated protein; D, Drosophila; GAP, GTPase activating protein; GEF, GTPase guanine nucleotide exchange factor; Hs, Homo sapiens/Human; Ig, Immunoglobulin; MAP, Microtubule associated Protein; MSP, Major Sperm Protein; MDP, Major Sperm Domain-Containing Protein; OCRL-1, Golgi endocytic trafficking protein Inositol polyphosphate 5-phosphatase; PAR, abnormal embryonic PARtitioning of the cytosol; PCM, Pericentriolar material; PCMD, pericentriolar matrix deficient; PDZ, PSD95/Dlg-1/zo-1; PLK, Polo like kinase; RMSD, Root Mean Square Deviation; SAS, Spindle assembly abnormal proteins; SPD, Spindle-defective protein; TRAPP, TRAnsport Protein Particle; Xe, Xenopus; ZYG, zygote defective protein.
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Affiliation(s)
- Mikaela Murph
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
| | - Shaneen Singh
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
- Department of Biology, The Graduate Center at City University of New York, New York, NY, USA
- Department Biochemistry, The Graduate Center at City University of New York, New York, NY, USA
| | - Mara Schvarzstein
- Department of Biology, City University of New York, Brooklyn College, New York, NY, USA
- Department of Biology, The Graduate Center at City University of New York, New York, NY, USA
- Department Biochemistry, The Graduate Center at City University of New York, New York, NY, USA
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31
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Zwicker D. The intertwined physics of active chemical reactions and phase separation. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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32
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Michieletto D, Marenda M. Rheology and Viscoelasticity of Proteins and Nucleic Acids Condensates. JACS AU 2022; 2:1506-1521. [PMID: 35911447 PMCID: PMC9326828 DOI: 10.1021/jacsau.2c00055] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Phase separation is as familiar as watching vinegar separating from oil in vinaigrette. The observation that phase separation of proteins and nucleic acids is widespread in living cells has opened an entire field of research into the biological significance and the biophysical mechanisms of phase separation and protein condensation in biology. Recent evidence indicates that certain proteins and nucleic acids condensates are not simple liquids and instead display both viscous and elastic behaviors, which in turn may have biological significance. The aim of this Perspective is to review the state-of-the-art of this quickly emerging field focusing on the material and rheological properties of protein condensates. Finally, we discuss the different techniques that can be employed to quantify the viscoelasticity of condensates and highlight potential future directions and opportunities for interdisciplinary cross-talk between chemists, physicists, and biologists.
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Affiliation(s)
- Davide Michieletto
- School
of Physics and Astronomy, University of
Edinburgh, Peter Guthrie
Tait Road, Edinburgh EH9
3FD, U.K.
- MRC
Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, U.K.
| | - Mattia Marenda
- School
of Physics and Astronomy, University of
Edinburgh, Peter Guthrie
Tait Road, Edinburgh EH9
3FD, U.K.
- MRC
Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, U.K.
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33
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Villegas JA, Levy ED. A unified statistical potential reveals that amino acid stickiness governs nonspecific recruitment of client proteins into condensates. Protein Sci 2022; 31:e4361. [PMID: 35762716 PMCID: PMC9207749 DOI: 10.1002/pro.4361] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/07/2022]
Abstract
Membraneless organelles are cellular compartments that form by liquid-liquid phase separation of one or more components. Other molecules, such as proteins and nucleic acids, will distribute between the cytoplasm and the liquid compartment in accordance with the thermodynamic drive to lower the free energy of the system. The resulting distribution colocalizes molecular species to carry out a diversity of functions. Two factors could drive this partitioning: the difference in solvation between the dilute versus dense phase and intermolecular interactions between the client and scaffold proteins. Here, we develop a set of knowledge-based potentials that allow for the direct comparison between stickiness, which is dominated by desolvation energy, and pairwise residue contact propensity terms. We use these scales to examine experimental data from two systems: protein cargo dissolving within phase-separated droplets made from FG repeat proteins of the nuclear pore complex and client proteins dissolving within phase-separated FUS droplets. These analyses reveal a close agreement between the stickiness of the client proteins and the experimentally determined values of the partition coefficients (R > 0.9), while pairwise residue contact propensities between client and scaffold show weaker correlations. Hence, the stickiness of client proteins is sufficient to explain their differential partitioning within these two phase-separated systems without taking into account the composition of the condensate. This result implies that selective trafficking of client proteins to distinct membraneless organelles requires recognition elements beyond the client sequence composition. STATEMENT: Empirical potentials for amino acid stickiness and pairwise residue contact propensities are derived. These scales are unique in that they enable direct comparison of desolvation versus contact terms. We find that partitioning of a client protein to a condensate is best explained by amino acid stickiness.
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Affiliation(s)
- José A. Villegas
- Department of Chemical and Structural BiologyWeizmann Institute of ScienceRehovotIsrael
- Present address:
Department of Pharmaceutical SciencesCollege of Pharmacy, University of Illinois ChicagoChicagoIL60612
| | - Emmanuel D. Levy
- Department of Chemical and Structural BiologyWeizmann Institute of ScienceRehovotIsrael
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34
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Size regulation of multiple organelles competing for a limiting subunit pool. PLoS Comput Biol 2022; 18:e1010253. [PMID: 35714135 PMCID: PMC9246132 DOI: 10.1371/journal.pcbi.1010253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 06/30/2022] [Accepted: 05/26/2022] [Indexed: 11/20/2022] Open
Abstract
How cells regulate the size of intracellular structures and organelles is a longstanding question. Recent experiments suggest that size control of intracellular structures is achieved through the depletion of a limiting subunit pool in the cytoplasm. While the limiting pool model ensures organelle-to-cell size scaling, it does not provide a mechanism for robust size control of multiple co-existing structures. Here we develop a generalized theory for size-dependent growth of intracellular structures to demonstrate that robust size control of multiple intracellular structures, competing for a limiting subunit pool, is achieved via a negative feedback between the growth rate and the size of the individual structure. This design principle captures size maintenance of a wide variety of subcellular structures, from cytoskeletal filaments to three-dimensional organelles. We identify the feedback motifs for structure size regulation based on known molecular processes, and compare our theory to existing models of size regulation in biological assemblies. Furthermore, we show that positive feedback between structure size and growth rate can lead to bistable size distribution and spontaneous size selection. Organelle size control is essential for the proper physiological functioning of eukaryotic cells, but the underlying mechanisms of size regulation remain poorly understood. By developing a general theory for organelle size control, we show that robust size control of intracellular structures and organelles is achieved via a negative feedback between individual organelle size and their net growth rates. This design principle not only describes size maintenance of single organelles, but also ensures size stability of multiple co-existing organelles that are built from a limiting pool of subunits. Our results delineate the role of limiting pool as a size scaling mechanism rather than a size control mechanism, supporting the idea that negative feedback control of organelle size via depletion of a limiting subunit pool is not sufficient to maintain the size of multiple competing organelles. In the case of positive feedback between organelle size and growth rate, our model reproduces phenomena such as bistability in organelle size distribution and spontaneous emergence of cell polarity.
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35
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Wong S, Wilmott ZM, Saurya S, Alvarez‐Rodrigo I, Zhou FY, Chau K, Goriely A, Raff JW. Centrioles generate a local pulse of Polo/PLK1 activity to initiate mitotic centrosome assembly. EMBO J 2022; 41:e110891. [PMID: 35505659 PMCID: PMC9156973 DOI: 10.15252/embj.2022110891] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/17/2022] [Accepted: 04/08/2022] [Indexed: 12/03/2022] Open
Abstract
Mitotic centrosomes are formed when centrioles start to recruit large amounts of pericentriolar material (PCM) around themselves in preparation for mitosis. This centrosome "maturation" requires the centrioles and also Polo/PLK1 protein kinase. The PCM comprises several hundred proteins and, in Drosophila, Polo cooperates with the conserved centrosome proteins Spd-2/CEP192 and Cnn/CDK5RAP2 to assemble a PCM scaffold around the mother centriole that then recruits other PCM client proteins. We show here that in Drosophila syncytial blastoderm embryos, centrosomal Polo levels rise and fall during the assembly process-peaking, and then starting to decline, even as levels of the PCM scaffold continue to rise and plateau. Experiments and mathematical modelling indicate that a centriolar pulse of Polo activity, potentially generated by the interaction between Polo and its centriole receptor Ana1 (CEP295 in humans), could explain these unexpected scaffold assembly dynamics. We propose that centrioles generate a local pulse of Polo activity prior to mitotic entry to initiate centrosome maturation, explaining why centrioles and Polo/PLK1 are normally essential for this process.
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Affiliation(s)
- Siu‐Shing Wong
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | - Zachary M Wilmott
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
- Mathematical InstituteUniversity of OxfordOxfordUK
| | - Saroj Saurya
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
| | | | - Felix Y Zhou
- Ludwig Institute for Cancer ResearchNuffield Department of Clinical MedicineUniversity of OxfordOxfordUK
- Present address:
Lyda Hill Department of BioinformaticsUniversity of Texas Southwestern Medical CenterDallasTXUSA
| | - Kwai‐Yin Chau
- Department of Computer ScienceUniversity of BathBathUK
| | | | - Jordan W Raff
- Sir William Dunn School of PathologyUniversity of OxfordOxfordUK
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36
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Nakajo M, Kano H, Tsuyama K, Haruta N, Sugimoto A. Centrosome maturation requires phosphorylation-mediated sequential domain interactions of SPD-5. J Cell Sci 2022; 135:274944. [PMID: 35362532 DOI: 10.1242/jcs.259025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 03/18/2022] [Indexed: 11/20/2022] Open
Abstract
Centrosomes consist of two centrioles and surrounding pericentriolar material (PCM). PCM expands during mitosis in a process called centrosome maturation, in which PCM scaffold proteins play pivotal roles to recruit other centrosomal proteins. In C. elegans, the scaffold protein SPD-5 forms PCM scaffold in a PLK-1 phosphorylation-dependent manner. However, how phosphorylation of SPD-5 promotes PCM scaffold assembly is unclear. Here, we identified three functional domains of SPD-5 through in vivo domain analyses, and propose that sequential domain interactions of SPD-5 are required for mitotic PCM scaffold assembly. Firstly, SPD-5 is targeted to centrioles through direct interaction between its centriole localization (CL) domain and a centriolar protein PCMD-1. Then, intra- and intermolecular interaction between SPD-5 phospho-regulated multimerization (PReM) domain and the PReM association (PA) domain is enhanced by phosphorylation by PLK-1, which leads to PCM scaffold expansion. Our findings suggest that the sequential domain interactions of scaffold proteins mediated by Polo/PLK-1 phosphorylation is an evolutionarily conserved mechanism of PCM scaffold assembly.
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Affiliation(s)
- Momoe Nakajo
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Hikaru Kano
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kenji Tsuyama
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Nami Haruta
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Asako Sugimoto
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
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37
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Abstract
Dormancy is an evolutionarily conserved protective mechanism widely observed in nature. A pathological example is found during cancer metastasis, where cancer cells disseminate from the primary tumor, home to secondary organs, and enter a growth-arrested state, which could last for decades. Recent studies have pointed toward the microenvironment being heavily involved in inducing, preserving, or ceasing this dormant state, with a strong focus on identifying specific molecular mechanisms and signaling pathways. Increasing evidence now suggests the existence of an interplay between intracellular as well as extracellular biochemical and mechanical cues in guiding such processes. Despite the inherent complexities associated with dormancy, proliferation, and growth of cancer cells and tumor tissues, viewing these phenomena from a physical perspective allows for a more global description, independent from many details of the systems. Building on the analogies between tissues and fluids and thermodynamic phase separation concepts, we classify a number of proposed mechanisms in terms of a thermodynamic metastability of the tumor with respect to growth. This can be governed by interaction with the microenvironment in the form of adherence (wetting) to a substrate or by mechanical confinement of the surrounding extracellular matrix. By drawing parallels with clinical and experimental data, we advance the notion that the local energy minima, or metastable states, emerging in the tissue droplet growth kinetics can be associated with a dormant state. Despite its simplicity, the provided framework captures several aspects associated with cancer dormancy and tumor growth.
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38
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Fassler JS, Skuodas S, Weeks DL, Phillips BT. Protein Aggregation and Disaggregation in Cells and Development. J Mol Biol 2021; 433:167215. [PMID: 34450138 PMCID: PMC8530975 DOI: 10.1016/j.jmb.2021.167215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/01/2021] [Accepted: 08/18/2021] [Indexed: 12/12/2022]
Abstract
Protein aggregation is a feature of numerous neurodegenerative diseases. However, regulated, often reversible, formation of protein aggregates, also known as condensates, helps control a wide range of cellular activities including stress response, gene expression, memory, cell development and differentiation. This review presents examples of aggregates found in biological systems, how they are used, and cellular strategies that control aggregation and disaggregation. We include features of the aggregating proteins themselves, environmental factors, co-aggregates, post-translational modifications and well-known aggregation-directed activities that influence their formation, material state, stability and dissolution. We highlight the emerging roles of biomolecular condensates in early animal development, and disaggregation processing proteins that have recently been shown to play key roles in gametogenesis and embryogenesis.
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Affiliation(s)
- Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States.
| | - Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@sskuodas
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, United States
| | - Bryan T Phillips
- Department of Biology, University of Iowa, Iowa City, IA 52242, United States. https://twitter.com/@bt4phillips
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39
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Merino-Salomón A, Babl L, Schwille P. Self-organized protein patterns: The MinCDE and ParABS systems. Curr Opin Cell Biol 2021; 72:106-115. [PMID: 34399108 DOI: 10.1016/j.ceb.2021.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/04/2021] [Accepted: 07/07/2021] [Indexed: 12/24/2022]
Abstract
Self-organized protein patterns are of tremendous importance for biological decision-making processes. Protein patterns have been shown to identify the site of future cell division, establish cell polarity, and organize faithful DNA segregation. Intriguingly, several key concepts of pattern formation and regulation apply to a variety of different protein systems. Herein, we explore recent advances in the understanding of two prokaryotic pattern-forming systems: the MinCDE system, positioning the FtsZ ring precisely at the midcell, and the ParABS system, distributing newly synthesized DNA along with the cell. Despite differences in biological functionality, these two systems have remarkably similar molecular components, mechanisms, and strategies to achieve biological robustness.
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Affiliation(s)
- Adrián Merino-Salomón
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152, Germany
| | - Leon Babl
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152, Germany
| | - Petra Schwille
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, 82152, Germany.
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40
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Pereira SG, Dias Louro MA, Bettencourt-Dias M. Biophysical and Quantitative Principles of Centrosome Biogenesis and Structure. Annu Rev Cell Dev Biol 2021; 37:43-63. [PMID: 34314592 DOI: 10.1146/annurev-cellbio-120219-051400] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The centrosome is a main orchestrator of the animal cellular microtubule cytoskeleton. Dissecting its structure and assembly mechanisms has been a goal of cell biologists for over a century. In the last two decades, a good understanding of the molecular constituents of centrosomes has been achieved. Moreover, recent breakthroughs in electron and light microscopy techniques have enabled the inspection of the centrosome and the mapping of its components with unprecedented detail. However, we now need a profound and dynamic understanding of how these constituents interact in space and time. Here, we review the latest findings on the structural and molecular architecture of the centrosome and how its biogenesis is regulated, highlighting how biophysical techniques and principles as well as quantitative modeling are changing our understanding of this enigmatic cellular organelle. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 37 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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41
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Nesterov SV, Ilyinsky NS, Uversky VN. Liquid-liquid phase separation as a common organizing principle of intracellular space and biomembranes providing dynamic adaptive responses. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119102. [PMID: 34293345 DOI: 10.1016/j.bbamcr.2021.119102] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/13/2021] [Accepted: 07/18/2021] [Indexed: 02/07/2023]
Abstract
This work is devoted to the phenomenon of liquid-liquid phase separation (LLPS), which has come to be recognized as fundamental organizing principle of living cells. We distinguish separation processes with different dimensions. Well-known 3D-condensation occurs in aqueous solution and leads to membraneless organelle (MLOs) formation. 2D-films may be formed near membrane surfaces and lateral phase separation (membrane rafts) occurs within the membranes themselves. LLPS may also occur on 1D structures like DNA and the cyto- and nucleoskeleton. Phase separation provides efficient transport and sorting of proteins and metabolites, accelerates the assembly of metabolic and signaling complexes, and mediates stress responses. In this work, we propose a model in which the processes of polymerization (1D structures), phase separation in membranes (2D structures), and LLPS in the volume (3D structures) influence each other. Disordered proteins and whole condensates may provide membrane raft separation or polymerization of specific proteins. On the other hand, 1D and 2D structures with special composition or embedded IDRs can nucleate condensates. We hypothesized that environmental change may trigger a LLPS which can propagate within the cell interior moving along the cytoskeleton or as an autowave. New phase propagation quickly and using a low amount of energy adjusts cell signaling and metabolic systems to new demands. Cumulatively, the interconnected phase separation phenomena in different dimensions represent a previously unexplored system of intracellular communication and regulation which cannot be ignored when considering both physiological and pathological cell processes.
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Affiliation(s)
- Semen V Nesterov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy pereulok, 9, Dolgoprudny 141700, Russia; Kurchatov Complex of NBICS-Technologies, National Research Center Kurchatov Institute, Moscow 123182, Russia.
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy pereulok, 9, Dolgoprudny 141700, Russia
| | - Vladimir N Uversky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Institutskiy pereulok, 9, Dolgoprudny 141700, Russia; Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC07, Tampa, FL 33612, USA.
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Jiang X, Ho DBT, Mahe K, Mia J, Sepulveda G, Antkowiak M, Jiang L, Yamada S, Jao LE. Condensation of pericentrin proteins in human cells illuminates phase separation in centrosome assembly. J Cell Sci 2021; 134:jcs258897. [PMID: 34308971 PMCID: PMC8349556 DOI: 10.1242/jcs.258897] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/08/2021] [Indexed: 11/24/2022] Open
Abstract
At the onset of mitosis, centrosomes expand the pericentriolar material (PCM) to maximize their microtubule-organizing activity. This step, termed centrosome maturation, ensures proper spindle organization and faithful chromosome segregation. However, as the centrosome expands, how PCM proteins are recruited and held together without membrane enclosure remains elusive. We found that endogenously expressed pericentrin (PCNT), a conserved PCM scaffold protein, condenses into dynamic granules during late G2/early mitosis before incorporating into mitotic centrosomes. Furthermore, the N-terminal portion of PCNT, enriched with conserved coiled-coils (CCs) and low-complexity regions (LCRs), phase separates into dynamic condensates that selectively recruit PCM proteins and nucleate microtubules in cells. We propose that CCs and LCRs, two prevalent sequence features in the centrosomal proteome, are preserved under evolutionary pressure in part to mediate liquid-liquid phase separation, a process that bestows upon the centrosome distinct properties critical for its assembly and functions.
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Affiliation(s)
- Xueer Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Dac Bang Tam Ho
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Karan Mahe
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Jennielee Mia
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Guadalupe Sepulveda
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Mark Antkowiak
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Linhao Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Soichiro Yamada
- Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA
| | - Li-En Jao
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
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43
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DEAD-Box RNA Helicases in Cell Cycle Control and Clinical Therapy. Cells 2021; 10:cells10061540. [PMID: 34207140 PMCID: PMC8234093 DOI: 10.3390/cells10061540] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 12/11/2022] Open
Abstract
Cell cycle is regulated through numerous signaling pathways that determine whether cells will proliferate, remain quiescent, arrest, or undergo apoptosis. Abnormal cell cycle regulation has been linked to many diseases. Thus, there is an urgent need to understand the diverse molecular mechanisms of how the cell cycle is controlled. RNA helicases constitute a large family of proteins with functions in all aspects of RNA metabolism, including unwinding or annealing of RNA molecules to regulate pre-mRNA, rRNA and miRNA processing, clamping protein complexes on RNA, or remodeling ribonucleoprotein complexes, to regulate gene expression. RNA helicases also regulate the activity of specific proteins through direct interaction. Abnormal expression of RNA helicases has been associated with different diseases, including cancer, neurological disorders, aging, and autosomal dominant polycystic kidney disease (ADPKD) via regulation of a diverse range of cellular processes such as cell proliferation, cell cycle arrest, and apoptosis. Recent studies showed that RNA helicases participate in the regulation of the cell cycle progression at each cell cycle phase, including G1-S transition, S phase, G2-M transition, mitosis, and cytokinesis. In this review, we discuss the essential roles and mechanisms of RNA helicases in the regulation of the cell cycle at different phases. For that, RNA helicases provide a rich source of targets for the development of therapeutic or prophylactic drugs. We also discuss the different targeting strategies against RNA helicases, the different types of compounds explored, the proposed inhibitory mechanisms of the compounds on specific RNA helicases, and the therapeutic potential of these compounds in the treatment of various disorders.
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44
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Lu JY, Chang L, Li T, Wang T, Yin Y, Zhan G, Han X, Zhang K, Tao Y, Percharde M, Wang L, Peng Q, Yan P, Zhang H, Bi X, Shao W, Hong Y, Wu Z, Ma R, Wang P, Li W, Zhang J, Chang Z, Hou Y, Zhu B, Ramalho-Santos M, Li P, Xie W, Na J, Sun Y, Shen X. Homotypic clustering of L1 and B1/Alu repeats compartmentalizes the 3D genome. Cell Res 2021; 31:613-630. [PMID: 33514913 PMCID: PMC8169921 DOI: 10.1038/s41422-020-00466-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/17/2020] [Indexed: 01/30/2023] Open
Abstract
Organization of the genome into euchromatin and heterochromatin appears to be evolutionarily conserved and relatively stable during lineage differentiation. In an effort to unravel the basic principle underlying genome folding, here we focus on the genome itself and report a fundamental role for L1 (LINE1 or LINE-1) and B1/Alu retrotransposons, the most abundant subclasses of repetitive sequences, in chromatin compartmentalization. We find that homotypic clustering of L1 and B1/Alu demarcates the genome into grossly exclusive domains, and characterizes and predicts Hi-C compartments. Spatial segregation of L1-rich sequences in the nuclear and nucleolar peripheries and B1/Alu-rich sequences in the nuclear interior is conserved in mouse and human cells and occurs dynamically during the cell cycle. In addition, de novo establishment of L1 and B1 nuclear segregation is coincident with the formation of higher-order chromatin structures during early embryogenesis and appears to be critically regulated by L1 and B1 transcripts. Importantly, depletion of L1 transcripts in embryonic stem cells drastically weakens homotypic repeat contacts and compartmental strength, and disrupts the nuclear segregation of L1- or B1-rich chromosomal sequences at genome-wide and individual sites. Mechanistically, nuclear co-localization and liquid droplet formation of L1 repeat DNA and RNA with heterochromatin protein HP1α suggest a phase-separation mechanism by which L1 promotes heterochromatin compartmentalization. Taken together, we propose a genetically encoded model in which L1 and B1/Alu repeats blueprint chromatin macrostructure. Our model explains the robustness of genome folding into a common conserved core, on which dynamic gene regulation is overlaid across cells.
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Affiliation(s)
- J Yuyang Lu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Lei Chang
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, Guangdong, 510005, China
| | - Tong Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ting Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yafei Yin
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ge Zhan
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xue Han
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ke Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yibing Tao
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Michelle Percharde
- MRC London Institute of Medical Sciences (LMS), London, W120NN, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, W120NN, UK
| | - Liang Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qi Peng
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Pixi Yan
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Hui Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xianju Bi
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wen Shao
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yantao Hong
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhongyang Wu
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Runze Ma
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Peizhe Wang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wenzhi Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jing Zhang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zai Chang
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yingping Hou
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China
| | - Bing Zhu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Miguel Ramalho-Santos
- Lunenfeld-Tanenbaum Research Institute, University of Toronto, Toronto, Ontario, M5T 3H7, Canada
| | - Pilong Li
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Xie
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jie Na
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, and College of Future Technology, Peking University, Beijing, 100871, China.
| | - Xiaohua Shen
- Tsinghua-Peking Joint Center for Life Sciences, School of Medicine and School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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45
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Kirschbaum J, Zwicker D. Controlling biomolecular condensates via chemical reactions. J R Soc Interface 2021; 18:20210255. [PMID: 34186016 PMCID: PMC8241490 DOI: 10.1098/rsif.2021.0255] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022] Open
Abstract
Biomolecular condensates are small droplets forming spontaneously in biological cells through phase separation. They play a role in many cellular processes, but it is unclear how cells control them. Cellular regulation often relies on post-translational modifications of proteins. For biomolecular condensates, such chemical modifications could alter the molecular interaction of key condensate components. Here, we test this idea using a theoretical model based on non-equilibrium thermodynamics. In particular, we describe the chemical reactions using transition-state theory, which accounts for the non-ideality of phase separation. We identify that fast control, as in cell signalling, is only possible when external energy input drives the reaction out of equilibrium. If this reaction differs inside and outside the droplet, it is even possible to control droplet sizes. Such an imbalance in the reaction could be created by enzymes localizing to the droplet. Since this situation is typical inside cells, we speculate that our proposed mechanism is used to stabilize multiple droplets with independently controlled size and count. Our model provides a novel and thermodynamically consistent framework for describing droplets subject to non-equilibrium chemical reactions.
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Affiliation(s)
- Jan Kirschbaum
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| | - David Zwicker
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
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46
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Floris E, Piras A, Dall’Asta L, Gamba A, Hirsch E, Campa CC. Physics of compartmentalization: How phase separation and signaling shape membrane and organelle identity. Comput Struct Biotechnol J 2021; 19:3225-3233. [PMID: 34141141 PMCID: PMC8190439 DOI: 10.1016/j.csbj.2021.05.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 05/15/2021] [Indexed: 11/29/2022] Open
Abstract
Compartmentalization of cellular functions is at the core of the physiology of eukaryotic cells. Recent evidences indicate that a universal organizing process - phase separation - supports the partitioning of biomolecules in distinct phases from a single homogeneous mixture, a landmark event in both the biogenesis and the maintenance of membrane and non-membrane-bound organelles. In the cell, 'passive' (non energy-consuming) mechanisms are flanked by 'active' mechanisms of separation into phases of distinct density and stoichiometry, that allow for increased partitioning flexibility and programmability. A convergence of physical and biological approaches is leading to new insights into the inner functioning of this driver of intracellular order, holding promises for future advances in both biological research and biotechnological applications.
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Affiliation(s)
- Elisa Floris
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Andrea Piras
- Italian Institute for Genomic Medicine (IIGM), c/o IRCCS Candiolo, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
- Candiolo Cancer Institute, FPO - IRCCS, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
| | - Luca Dall’Asta
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
- Collegio Carlo Alberto, Piazza Arbarello 8, 10122 Torino, Italy
| | - Andrea Gamba
- Institute of Condensed Matter Physics and Complex Systems, Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
- Italian Institute for Genomic Medicine (IIGM), c/o IRCCS Candiolo, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
- Candiolo Cancer Institute, FPO - IRCCS, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
- Istituto Nazionale di Fisica Nucleare (INFN), sezione di Torino, Via Giuria 1, 10125 Torino, Italy
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Via Nizza 52, 10126 Torino, Italy
| | - Carlo C. Campa
- Italian Institute for Genomic Medicine (IIGM), c/o IRCCS Candiolo, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
- Candiolo Cancer Institute, FPO - IRCCS, Str.Prov.le 142, km 3.95, Candiolo (TO) 10060, Italy
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47
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Dünkler A, Leda M, Kromer JM, Neller J, Gronemeyer T, Goryachev AB, Johnsson N. Type V myosin focuses the polarisome and shapes the tip of yeast cells. J Cell Biol 2021; 220:211845. [PMID: 33656555 PMCID: PMC7933982 DOI: 10.1083/jcb.202006193] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/25/2021] [Accepted: 02/04/2021] [Indexed: 11/22/2022] Open
Abstract
The polarisome is a cortical proteinaceous microcompartment that organizes the growth of actin filaments and the fusion of secretory vesicles in yeasts and filamentous fungi. Polarisomes are compact, spotlike structures at the growing tips of their respective cells. The molecular forces that control the form and size of this microcompartment are not known. Here we identify a complex between the polarisome subunit Pea2 and the type V Myosin Myo2 that anchors Myo2 at the cortex of yeast cells. We discovered a point mutation in the cargo-binding domain of Myo2 that impairs the interaction with Pea2 and consequently the formation and focused localization of the polarisome. Cells carrying this mutation grow round instead of elongated buds. Further experiments and biophysical modeling suggest that the interactions between polarisome-bound Myo2 motors and dynamic actin filaments spatially focus the polarisome and sustain its compact shape.
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Affiliation(s)
- Alexander Dünkler
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Marcin Leda
- Centre for Synthetic and Systems Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Jan-Michael Kromer
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Joachim Neller
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Thomas Gronemeyer
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
| | - Andrew B Goryachev
- Centre for Synthetic and Systems Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Nils Johnsson
- Institute of Molecular Genetics and Cell Biology, Department of Biology, Ulm University, Ulm, Germany
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48
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Hagan MF, Grason GM. Equilibrium mechanisms of self-limiting assembly. REVIEWS OF MODERN PHYSICS 2021; 93:025008. [PMID: 35221384 PMCID: PMC8880259 DOI: 10.1103/revmodphys.93.025008] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Self-assembly is a ubiquitous process in synthetic and biological systems, broadly defined as the spontaneous organization of multiple subunits (e.g. macromolecules, particles) into ordered multi-unit structures. The vast majority of equilibrium assembly processes give rise to two states: one consisting of dispersed disassociated subunits, and the other, a bulk-condensed state of unlimited size. This review focuses on the more specialized class of self-limiting assembly, which describes equilibrium assembly processes resulting in finite-size structures. These systems pose a generic and basic question, how do thermodynamic processes involving non-covalent interactions between identical subunits "measure" and select the size of assembled structures? In this review, we begin with an introduction to the basic statistical mechanical framework for assembly thermodynamics, and use this to highlight the key physical ingredients that ensure equilibrium assembly will terminate at finite dimensions. Then, we introduce examples of self-limiting assembly systems, and classify them within this framework based on two broad categories: self-closing assemblies and open-boundary assemblies. These include well-known cases in biology and synthetic soft matter - micellization of amphiphiles and shell/tubule formation of tapered subunits - as well as less widely known classes of assemblies, such as short-range attractive/long-range repulsive systems and geometrically-frustrated assemblies. For each of these self-limiting mechanisms, we describe the physical mechanisms that select equilibrium assembly size, as well as potential limitations of finite-size selection. Finally, we discuss alternative mechanisms for finite-size assemblies, and draw contrasts with the size-control that these can achieve relative to self-limitation in equilibrium, single-species assemblies.
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Affiliation(s)
- Michael F Hagan
- Martin Fisher School of Physics, Brandeis University, Waltham, MA 02454, USA
| | - Gregory M Grason
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003, USA
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49
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Morales-Polanco F, Bates C, Lui J, Casson J, Solari CA, Pizzinga M, Forte G, Griffin C, Garner KEL, Burt HE, Dixon HL, Hubbard S, Portela P, Ashe MP. Core Fermentation (CoFe) granules focus coordinated glycolytic mRNA localization and translation to fuel glucose fermentation. iScience 2021; 24:102069. [PMID: 33554071 PMCID: PMC7859310 DOI: 10.1016/j.isci.2021.102069] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/16/2020] [Accepted: 01/12/2021] [Indexed: 12/24/2022] Open
Abstract
Glycolysis is a fundamental metabolic pathway for glucose catabolism across biology, and glycolytic enzymes are among the most abundant proteins in cells. Their expression at such levels provides a particular challenge. Here we demonstrate that the glycolytic mRNAs are localized to granules in yeast and human cells. Detailed live cell and smFISH studies in yeast show that the mRNAs are actively translated in granules, and this translation appears critical for the localization. Furthermore, this arrangement is likely to facilitate the higher level organization and control of the glycolytic pathway. Indeed, the degree of fermentation required by cells is intrinsically connected to the extent of mRNA localization to granules. On this basis, we term these granules, core fermentation (CoFe) granules; they appear to represent translation factories, allowing high-level coordinated enzyme synthesis for a critical metabolic pathway.
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Affiliation(s)
- Fabian Morales-Polanco
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Christian Bates
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Jennifer Lui
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Joseph Casson
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Clara A Solari
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Mariavittoria Pizzinga
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Gabriela Forte
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Claire Griffin
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Kirsten E L Garner
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Harriet E Burt
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Hannah L Dixon
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Simon Hubbard
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Paula Portela
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina
| | - Mark P Ashe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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50
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Roy S, Chen YL. Rich phase transitions in strongly confined polymer-nanoparticle mixtures: Nematic ordering, crystallization, and liquid-liquid phase separation. J Chem Phys 2021; 154:024901. [PMID: 33445888 DOI: 10.1063/5.0034602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the rich phase behavior of strongly confined semi-flexible (SFC) polymer-nanoparticle (NP) systems using the graphics processing unit accelerated Langevin dynamics simulation. Hard nanoparticles (HNP) that repel each other and ideal nanoparticles (INP) that do not interact with the same species are used as model additives to a strongly confined semiflexible polymer fluid. Both types of NPs exclude the monomer beads in the same way, but they have qualitatively different effects on the SFC isotropic-nematic (I-N) transition. For the total volume fraction ϕtot < 0.16, adding a low volume fraction of HNPs (ϕp) disrupts the long range nematic order of the polymers, whereas adding HNPs in a moderately packed system (0.16 < ϕtot < 0.32) facilitates polymer alignment due to the restricted polymer orientational degree of freedom. For dense packing (ϕtot > 0.32), polymers and NPs separate into layers along the slit height and the NPs form crystalline microdomains. In contrast, INP additives always promote inter-polymer alignment for low to moderate monomer volume fractions (ϕm). Furthermore, we found that INPs form a droplet-like fluid domain in dense nematic polymer systems.
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Affiliation(s)
- Supriya Roy
- Institute of Physics, Academia Sinica, Taipei, Taiwan
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