1
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Zhang X, Yuan L, Zhang W, Zhang Y, Wu Q, Li C, Wu M, Huang Y. Liquid-liquid phase separation in diseases. MedComm (Beijing) 2024; 5:e640. [PMID: 39006762 PMCID: PMC11245632 DOI: 10.1002/mco2.640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 07/16/2024] Open
Abstract
Liquid-liquid phase separation (LLPS), an emerging biophysical phenomenon, can sequester molecules to implement physiological and pathological functions. LLPS implements the assembly of numerous membraneless chambers, including stress granules and P-bodies, containing RNA and protein. RNA-RNA and RNA-protein interactions play a critical role in LLPS. Scaffolding proteins, through multivalent interactions and external factors, support protein-RNA interaction networks to form condensates involved in a variety of diseases, particularly neurodegenerative diseases and cancer. Modulating LLPS phenomenon in multiple pathogenic proteins for the treatment of neurodegenerative diseases and cancer could present a promising direction, though recent advances in this area are limited. Here, we summarize in detail the complexity of LLPS in constructing signaling pathways and highlight the role of LLPS in neurodegenerative diseases and cancers. We also explore RNA modifications on LLPS to alter diseases progression because these modifications can influence LLPS of certain proteins or the formation of stress granules, and discuss the possibility of proper manipulation of LLPS process to restore cellular homeostasis or develop therapeutic drugs for the eradication of diseases. This review attempts to discuss potential therapeutic opportunities by elaborating on the connection between LLPS, RNA modification, and their roles in diseases.
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Affiliation(s)
- Xinyue Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Lin Yuan
- Laboratory of Research in Parkinson's Disease and Related Disorders Health Sciences Institute China Medical University Shenyang China
| | - Wanlu Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Yi Zhang
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Qun Wu
- Department of Pediatrics Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine Shanghai China
| | - Chunting Li
- College of Life and Health Sciences Northeastern University Shenyang China
| | - Min Wu
- Wenzhou Institute University of Chinese Academy of Sciences Wenzhou Zhejiang China
- The Joint Research Center Affiliated Xiangshan Hospital of Wenzhou Medical University Ningbo China
| | - Yongye Huang
- College of Life and Health Sciences Northeastern University Shenyang China
- Key Laboratory of Bioresource Research and Development of Liaoning Province College of Life and Health Sciences Northeastern University Shenyang China
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2
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Mangiarotti A, Dimova R. Biomolecular Condensates in Contact with Membranes. Annu Rev Biophys 2024; 53:319-341. [PMID: 38360555 DOI: 10.1146/annurev-biophys-030722-121518] [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] [Indexed: 02/17/2024]
Abstract
Biomolecular condensates are highly versatile membraneless organelles involved in a plethora of cellular processes. Recent years have witnessed growing evidence of the interaction of these droplets with membrane-bound cellular structures. Condensates' adhesion to membranes can cause their mutual molding and regulation, and their interaction is of fundamental relevance to intracellular organization and communication, organelle remodeling, embryogenesis, and phagocytosis. In this article, we review advances in the understanding of membrane-condensate interactions, with a focus on in vitro models. These minimal systems allow the precise characterization and tuning of the material properties of both membranes and condensates and provide a workbench for visualizing the resulting morphologies and quantifying the interactions. These interactions can give rise to diverse biologically relevant phenomena, such as molecular-level restructuring of the membrane, nano- to microscale ruffling of the condensate-membrane interface, and coupling of the protein and lipid phases.
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Affiliation(s)
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Potsdam, Germany;
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3
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Weakly HMJ, Keller SL. Coupling liquid phases in 3D condensates and 2D membranes: Successes, challenges, and tools. Biophys J 2024; 123:1329-1341. [PMID: 38160256 PMCID: PMC11163299 DOI: 10.1016/j.bpj.2023.12.023] [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: 09/21/2023] [Revised: 12/05/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024] Open
Abstract
This review describes the major experimental challenges researchers meet when attempting to couple phase separation between membranes and condensates. Although it is well known that phase separation in a 2D membrane could affect molecules capable of forming a 3D condensate (and vice versa), few researchers have quantified the effects to date. The scarcity of these measurements is not due to a lack of intense interest or effort in the field. Rather, it reflects significant experimental challenges in manipulating coupled membranes and condensates to yield quantitative values. These challenges transcend many molecular details, which means they impact a wide range of systems. This review highlights recent exciting successes in the field, and it lays out a comprehensive list of tools that address potential pitfalls for researchers who are considering coupling membranes with condensates.
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Affiliation(s)
- Heidi M J Weakly
- Department of Chemistry, University of Washington - Seattle, Seattle, Washington
| | - Sarah L Keller
- Department of Chemistry, University of Washington - Seattle, Seattle, Washington.
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4
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Murai T. Transmembrane signaling through single-spanning receptors modulated by phase separation at the cell surface. Eur J Cell Biol 2024; 103:151413. [PMID: 38631097 DOI: 10.1016/j.ejcb.2024.151413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/19/2024] Open
Abstract
A wide variety of transmembrane signals are transduced by cell-surface receptors that activate intracellular signaling molecules. In particular, receptor clustering in the plasma membrane plays a critical role in these processes. Single-spanning or single-pass transmembrane proteins are among the most significant types of membrane receptors, which include adhesion receptors, such as integrins, CD44, cadherins, and receptor tyrosine kinases. Elucidating the molecular mechanisms underlying the regulation of the activity of these receptors is of great significance. Liquid-liquid phase separation (LLPS) is a recently emerging paradigm in cellular physiology for the ubiquitous regulation of the spatiotemporal dynamics of various signaling pathways. This study describes the emerging features of transmembrane signaling through single-spanning receptors from the perspective of phase separation. Possible physicochemical modulations of LLPS-based transmembrane signaling are also discussed.
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Affiliation(s)
- Toshiyuki Murai
- Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
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5
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Min S, Picou C, Jeong HJ, Bower A, Jeong K, Chung JK. Melittin-Phospholipase A 2 Synergism Is Mediated by Liquid-Liquid Miscibility Phase Transition in Giant Unilamellar Vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:7456-7462. [PMID: 38546877 DOI: 10.1021/acs.langmuir.3c03920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
The primary constituents of honeybee venom, melittin and phospholipase A2 (PLA2), display toxin synergism in which the PLA2 activity is significantly enhanced by the presence of melittin. It has been shown previously that this is accomplished by the disruption in lipid packing, which allows PLA2 to become processive on the membrane surface. In this work, we show that melittin is capable of driving miscibility phase transition in giant unilamellar vesicles (GUVs) and that it raises the miscibility transition temperature (Tmisc) in a concentration-dependent manner. The induced phase separation enhances the processivity of PLA2, particularly at its boundaries, where a substantial difference in domain thickness creates a membrane discontinuity. The catalytic action of PLA2, in response, induces changes in the membrane, rendering it more conducive to melittin binding. This, in turn, facilitates further lipid phase separation and eventual vesicle lysis. Overall, our results show that melittin has powerful membrane-altering capabilities that activate PLA2 in various membrane contexts. More broadly, they exemplify how this biochemical system actively modulates and capitalizes on the spatial distribution of membrane lipids to efficiently achieve its objectives.
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Affiliation(s)
- Sein Min
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
| | - Cyrus Picou
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
| | - Hye Jin Jeong
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
| | - Adam Bower
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
| | - Keunhong Jeong
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
| | - Jean K Chung
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
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6
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Mondal S, Cui Q. Sequence Sensitivity in Membrane Remodeling by Polyampholyte Condensates. J Phys Chem B 2024; 128:2087-2099. [PMID: 38407041 DOI: 10.1021/acs.jpcb.3c08149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Intrinsically disordered peptides (IDPs) have been found to undergo liquid-liquid phase separation (LLPS) and produce complex coacervates that play numerous regulatory roles in the cell. Recent experimental studies have discovered that LLPS at or near the membrane surface helps in the biomolecular organization during signaling events and can significantly alter the membrane morphology. However, the molecular mechanism and microscopic details of such processes still remain unclear. Here we study the effect of polyampholyte and polyelectrolyte condensation on two different anionic membranes, as they represent a majority of naturally occurring IDPs. The polyampholytes are fifty-residue polymers, made of glutamate(E) and lysine(K) with different charge patterns. The polyelectrolytes are separate chains of E25 and K25. We first calibrate the MARTINI v3.0 force field and then perform long-time-scale coarse-grained molecular dynamics simulations. We find that condensates formed by all the polyampholytes get adsorbed on the membrane. However, the strong polyampholytes (i.e., blocky sequences) can remodel the membranes more prominently than the weaker ones (i.e., scrambled sequences). Condensates formed by the blocky sequences induce a significant negative curvature (∼0.1 nm-1) and local demixing of lipids, whereas those by the scrambled sequences tend to wet the membrane to a greater extent without generating significant curvature or demixing. We perform several microscopic analyses to characterize the nature of the interaction between membranes and these condensates. Our analyses of interaction energetics reveal that membrane remodeling and/or wetting are favored by enhanced interactions between polyampholytes with lipids and the counterions.
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Affiliation(s)
- Sayantan Mondal
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Qiang Cui
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, Massachusetts 02215, United States
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7
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Huang WYC, Boxer SG, Ferrell JE. Membrane localization accelerates association under conditions relevant to cellular signaling. Proc Natl Acad Sci U S A 2024; 121:e2319491121. [PMID: 38427601 PMCID: PMC10927583 DOI: 10.1073/pnas.2319491121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 01/16/2024] [Indexed: 03/03/2024] Open
Abstract
Translocation of cytoplasmic molecules to the plasma membrane is commonplace in cell signaling. Membrane localization has been hypothesized to increase intermolecular association rates; however, it has also been argued that association should be faster in the cytosol because membrane diffusion is slow. Here, we directly compare an identical association reaction, the binding of complementary DNA strands, in solution and on supported membranes. The measured rate constants show that for a 10-µm-radius spherical cell, association is 22- to 33-fold faster at the membrane than in the cytoplasm. The kinetic advantage depends on cell size and is essentially negligible for typical ~1 µm prokaryotic cells. The rate enhancement is attributable to a combination of higher encounter rates in two dimensions and a higher reaction probability per encounter.
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Affiliation(s)
- William Y. C. Huang
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA94305
| | - Steven G. Boxer
- Department of Chemistry, Stanford University, Stanford, CA94305
| | - James E. Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA94305
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
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8
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Lee Y, Park S, Yuan F, Hayden CC, Wang L, Lafer EM, Choi SQ, Stachowiak JC. Transmembrane coupling of liquid-like protein condensates. Nat Commun 2023; 14:8015. [PMID: 38049424 PMCID: PMC10696066 DOI: 10.1038/s41467-023-43332-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 11/06/2023] [Indexed: 12/06/2023] Open
Abstract
Liquid-liquid phase separation of proteins occurs on both surfaces of cellular membranes during diverse physiological processes. In vitro reconstitution could provide insight into the mechanisms underlying these events. However, most existing reconstitution techniques provide access to only one membrane surface, making it difficult to probe transmembrane phenomena. To study protein phase separation simultaneously on both membrane surfaces, we developed an array of freestanding planar lipid membranes. Interestingly, we observed that liquid-like protein condensates on one side of the membrane colocalized with those on the other side, resulting in transmembrane coupling. Our results, based on lipid probe partitioning and mobility of lipids, suggest that protein condensates locally reorganize membrane lipids, a process which could be explained by multiple effects. These findings suggest a mechanism by which signals originating on one side of a biological membrane, triggered by protein phase separation, can be transferred to the opposite side.
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Affiliation(s)
- Yohan Lee
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Sujin Park
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Feng Yuan
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Carl C Hayden
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Liping Wang
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Eileen M Lafer
- Department of Biochemistry and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Siyoung Q Choi
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.
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9
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Cheng X, Case LB. Phase separation in chemical and mechanical signal transduction. Curr Opin Cell Biol 2023; 85:102243. [PMID: 37788587 DOI: 10.1016/j.ceb.2023.102243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/09/2023] [Accepted: 09/03/2023] [Indexed: 10/05/2023]
Abstract
Signal transduction enables cells to sense and respond to chemical and mechanical information in the extracellular environment. Recently, phase separation has emerged as a physical mechanism that can influence the spatial organization of signaling molecules and regulate downstream signaling. Although many molecular components of signaling pathways, including receptors, kinases, and transcription factors, have been observed to undergo phase separation, understanding the functional consequences of their phase separation in signal transduction remains an ongoing area of research. In this review, we will discuss recent studies investigating how cells potentially use phase separation to regulate different signaling pathways by initiating signaling, amplifying signaling, or inhibiting signaling. We will also discuss recent observations that suggest a role for phase separation in mechanosensing in the Hippo pathway and at focal adhesions.
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Affiliation(s)
- Xiaohang Cheng
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lindsay B Case
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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10
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Shelby SA, Veatch SL. The Membrane Phase Transition Gives Rise to Responsive Plasma Membrane Structure and Function. Cold Spring Harb Perspect Biol 2023; 15:a041395. [PMID: 37553204 PMCID: PMC10626261 DOI: 10.1101/cshperspect.a041395] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Several groups have recently reported evidence for the emergence of domains in cell plasma membranes when membrane proteins are organized by ligand binding or assembly of membrane proximal scaffolds. These domains recruit and retain components that favor the liquid-ordered phase, adding to a decades-old literature interrogating the contribution of membrane phase separation in plasma membrane organization and function. Here we propose that both past and present observations are consistent with a model in which membranes have a high compositional susceptibility, arising from their thermodynamic state in a single phase that is close to a miscibility phase transition. This rigorous framework naturally allows for both transient structure in the form of composition fluctuations and long-lived structure in the form of induced domains. In this way, the biological tuning of plasma membrane composition enables a responsive compositional landscape that facilitates and augments cellular biochemistry vital to plasma membrane functions.
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Affiliation(s)
- Sarah A Shelby
- Biochemistry & Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, Tennessee 37996, USA
| | - Sarah L Veatch
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA
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11
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Mangiarotti A, Siri M, Tam NW, Zhao Z, Malacrida L, Dimova R. Biomolecular condensates modulate membrane lipid packing and hydration. Nat Commun 2023; 14:6081. [PMID: 37770422 PMCID: PMC10539446 DOI: 10.1038/s41467-023-41709-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 09/15/2023] [Indexed: 09/30/2023] Open
Abstract
Membrane wetting by biomolecular condensates recently emerged as a key phenomenon in cell biology, playing an important role in a diverse range of processes across different organisms. However, an understanding of the molecular mechanisms behind condensate formation and interaction with lipid membranes is still missing. To study this, we exploited the properties of the dyes ACDAN and LAURDAN as nano-environmental sensors in combination with phasor analysis of hyperspectral and lifetime imaging microscopy. Using glycinin as a model condensate-forming protein and giant vesicles as model membranes, we obtained vital information on the process of condensate formation and membrane wetting. Our results reveal that glycinin condensates display differences in water dynamics when changing the salinity of the medium as a consequence of rearrangements in the secondary structure of the protein. Remarkably, analysis of membrane-condensates interaction with protein as well as polymer condensates indicated a correlation between increased wetting affinity and enhanced lipid packing. This is demonstrated by a decrease in the dipolar relaxation of water across all membrane-condensate systems, suggesting a general mechanism to tune membrane packing by condensate wetting.
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Affiliation(s)
- Agustín Mangiarotti
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany.
| | - Macarena Siri
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Nicky W Tam
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Ziliang Zhao
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743, Jena, Germany
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
- Advanced Bioimaging Unit, Institut Pasteur of Montevideo and Universidad de la República, Montevideo, Uruguay.
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany.
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12
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Sakamoto K, Akimoto T, Muramatsu M, Sansom MSP, Metzler R, Yamamoto E. Heterogeneous biological membranes regulate protein partitioning via fluctuating diffusivity. PNAS NEXUS 2023; 2:pgad258. [PMID: 37593200 PMCID: PMC10427746 DOI: 10.1093/pnasnexus/pgad258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/22/2023] [Accepted: 07/27/2023] [Indexed: 08/19/2023]
Abstract
Cell membranes phase separate into ordered L o and disordered L d domains depending on their compositions. This membrane compartmentalization is heterogeneous and regulates the localization of specific proteins related to cell signaling and trafficking. However, it is unclear how the heterogeneity of the membranes affects the diffusion and localization of proteins in L o and L d domains. Here, using Langevin dynamics simulations coupled with the phase-field (LDPF) method, we investigate several tens of milliseconds-scale diffusion and localization of proteins in heterogeneous biological membrane models showing phase separation into L o and L d domains. The diffusivity of proteins exhibits temporal fluctuations depending on the field composition. Increases in molecular concentrations and domain preference of the molecule induce subdiffusive behavior due to molecular collisions by crowding and confinement effects, respectively. Moreover, we quantitatively demonstrate that the protein partitioning into the L o domain is determined by the difference in molecular diffusivity between domains, molecular preference of domain, and molecular concentration. These results pave the way for understanding how biological reactions caused by molecular partitioning may be controlled in heterogeneous media. Moreover, the methodology proposed here is applicable not only to biological membrane systems but also to the study of diffusion and localization phenomena of molecules in various heterogeneous systems.
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Affiliation(s)
- Ken Sakamoto
- Department of System Design Engineering, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Takuma Akimoto
- Department of Physics, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Mayu Muramatsu
- Department of Mechanical Engineering, Keio University, Yokohama, Kanagawa 223-8522, Japan
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Ralf Metzler
- Institute of Physics & Astronomy, University of Potsdam, Potsdam-Golm 14476, Germany
- Asia Pacific Centre for Theoretical Physics, Pohang 37673, Republic of Korea
| | - Eiji Yamamoto
- Department of System Design Engineering, Keio University, Yokohama, Kanagawa 223-8522, Japan
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13
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Li R, Pang L. Comparing the effects of proteins with IDRs on membrane system in yeast, mammalian cells, and the model plant Arabidopsis. CURRENT OPINION IN PLANT BIOLOGY 2023; 74:102375. [PMID: 37172364 DOI: 10.1016/j.pbi.2023.102375] [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: 12/21/2022] [Revised: 03/26/2023] [Accepted: 04/07/2023] [Indexed: 05/14/2023]
Abstract
Membrane vesiculation is an energy-costing process. Previous studies paid much attention to proteins with curvature-inducing motifs. Recent publications reveal that the liquid-like protein assembly on membrane surfaces provides an efficient yet structure-independent mechanism for increasing the membrane curvature, which plays important roles in vesicle transport in many aspects. Intrinsically disordered regions (IDRs) within the proteins are highly potent drivers of membrane curvature by providing large hydrodynamic radii to generate steric pressure. Biomolecular condensates formed by phase separation can provide a reaction platform for sequential processes or generate a wetting surface to sequestrate cargos and trigger membrane remodeling. We review the latest progress in yeast and mammalian cells, focus on the mechanism of clathrin-mediated endocytosis (CME) and autophagy initiation, and compare with what we know in model plant Arabidopsis. The comparison may give important insights into the understanding of basic membrane trafficking mechanisms in plant cells.
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Affiliation(s)
- Ruixi Li
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Lei Pang
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China
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14
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Guo X, Zhu K, Zhu X, Zhao W, Miao Y. Two-dimensional molecular condensation in cell signaling and mechanosensing. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1064-1074. [PMID: 37475548 PMCID: PMC10423693 DOI: 10.3724/abbs.2023132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/21/2023] [Indexed: 07/22/2023] Open
Abstract
Membraneless organelles (MLO) regulate diverse biological processes in a spatiotemporally controlled manner spanning from inside to outside of the cells. The plasma membrane (PM) at the cell surface serves as a central platform for forming multi-component signaling hubs that sense mechanical and chemical cues during physiological and pathological conditions. During signal transduction, the assembly and formation of membrane-bound MLO are dynamically tunable depending on the physicochemical properties of the surrounding environment and partitioning biomolecules. Biomechanical properties of MLO-associated membrane structures can control the microenvironment for biomolecular interactions and assembly. Lipid-protein complex interactions determine the catalytic region's assembly pattern and assembly rate and, thereby, the amplitude of activities. In this review, we will focus on how cell surface microenvironments, including membrane curvature, surface topology and tension, lipid-phase separation, and adhesion force, guide the assembly of PM-associated MLO for cell signal transductions.
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Affiliation(s)
- Xiangfu Guo
- School of ChemistryChemical Engineering and BiotechnologyNanyang Technological UniversitySingapore637457Singapore
| | - Kexin Zhu
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
| | - Xinlu Zhu
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
| | - Wenting Zhao
- School of ChemistryChemical Engineering and BiotechnologyNanyang Technological UniversitySingapore637457Singapore
- Institute for Digital Molecular Analytics and ScienceNanyang Technological UniversitySingapore636921Singapore
| | - Yansong Miao
- School of Biological SciencesNanyang Technological UniversitySingapore637551Singapore
- Institute for Digital Molecular Analytics and ScienceNanyang Technological UniversitySingapore636921Singapore
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15
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Shelby SA, Castello-Serrano I, Wisser KC, Levental I, Veatch SL. Membrane phase separation drives responsive assembly of receptor signaling domains. Nat Chem Biol 2023; 19:750-758. [PMID: 36997644 PMCID: PMC10771812 DOI: 10.1038/s41589-023-01268-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 01/17/2023] [Indexed: 04/01/2023]
Abstract
Plasma membrane heterogeneity has been tied to a litany of cellular functions and is often explained by analogy to membrane phase separation; however, models based on phase separation alone fall short of describing the rich organization available within cell membranes. Here we present comprehensive experimental evidence motivating an updated model of plasma membrane heterogeneity in which membrane domains assemble in response to protein scaffolds. Quantitative super-resolution nanoscopy measurements in live B lymphocytes detect membrane domains that emerge upon clustering B cell receptors (BCRs). These domains enrich and retain membrane proteins based on their preference for the liquid-ordered phase. Unlike phase-separated membranes that consist of binary phases with defined compositions, membrane composition at BCR clusters is modulated through the protein constituents in clusters and the composition of the membrane overall. This tunable domain structure is detected through the variable sorting of membrane probes and impacts the magnitude of BCR activation.
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Affiliation(s)
- Sarah A Shelby
- Program in Biophysics, University of Michigan, Ann Arbor, MI, USA
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, TN, USA
| | - Ivan Castello-Serrano
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | | | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
| | - Sarah L Veatch
- Program in Biophysics, University of Michigan, Ann Arbor, MI, USA.
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16
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Wang HY, Chan SH, Dey S, Castello-Serrano I, Rosen MK, Ditlev JA, Levental KR, Levental I. Coupling of protein condensates to ordered lipid domains determines functional membrane organization. SCIENCE ADVANCES 2023; 9:eadf6205. [PMID: 37126554 PMCID: PMC10132753 DOI: 10.1126/sciadv.adf6205] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
During T cell activation, the transmembrane adaptor protein LAT (linker for activation of T cells) forms biomolecular condensates with Grb2 and Sos1, facilitating signaling. LAT has also been associated with cholesterol-rich condensed lipid domains; However, the potential coupling between protein condensation and lipid phase separation and its role in organizing T cell signaling were unknown. Here, we report that LAT/Grb2/Sos1 condensates reconstituted on model membranes can induce and template lipid domains, indicating strong coupling between lipid- and protein-based phase separation. Correspondingly, activation of T cells induces cytoplasmic protein condensates that associate with and stabilize raft-like membrane domains. Inversely, lipid domains nucleate and stabilize LAT protein condensates in both reconstituted and living systems. This coupling of lipid and protein assembly is functionally important, as uncoupling of lipid domains from cytoplasmic protein condensates abrogates T cell activation. Thus, thermodynamic coupling between protein condensates and ordered lipid domains regulates the functional organization of living membranes.
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Affiliation(s)
- Hong-Yin Wang
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Sze Ham Chan
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Simli Dey
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Ivan Castello-Serrano
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Michael K Rosen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathon A Ditlev
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Program in Molecular Medicine, Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Kandice R Levental
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, VA 22903, USA
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17
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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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18
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Nixon-Abell J, Ruggeri FS, Qamar S, Herling TW, Czekalska MA, Shen Y, Wang G, King C, Fernandopulle MS, Sneideris T, Watson JL, Pillai VVS, Meadows W, Henderson JW, Chambers JE, Wagstaff JL, Williams SH, Coyle H, Lu Y, Zhang S, Marciniak SJ, Freund SMV, Derivery E, Ward ME, Vendruscolo M, Knowles TPJ, St George-Hyslop P. ANXA11 biomolecular condensates facilitate protein-lipid phase coupling on lysosomal membranes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.22.533832. [PMID: 36993242 PMCID: PMC10055329 DOI: 10.1101/2023.03.22.533832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Phase transitions of cellular proteins and lipids play a key role in governing the organisation and coordination of intracellular biology. The frequent juxtaposition of proteinaceous biomolecular condensates to cellular membranes raises the intriguing prospect that phase transitions in proteins and lipids could be co-regulated. Here we investigate this possibility in the ribonucleoprotein (RNP) granule-ANXA11-lysosome ensemble, where ANXA11 tethers RNP granule condensates to lysosomal membranes to enable their co-trafficking. We show that changes to the protein phase state within this system, driven by the low complexity ANXA11 N-terminus, induce a coupled phase state change in the lipids of the underlying membrane. We identify the ANXA11 interacting proteins ALG2 and CALC as potent regulators of ANXA11-based phase coupling and demonstrate their influence on the nanomechanical properties of the ANXA11-lysosome ensemble and its capacity to engage RNP granules. The phenomenon of protein-lipid phase coupling we observe within this system offers an important template to understand the numerous other examples across the cell whereby biomolecular condensates closely juxtapose cell membranes. GRAPHICAL ABSTRACT
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19
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Joshi A, Mukhopadhyay S. Biophysics of biomolecular condensates. Biophys J 2023; 122:737-740. [PMID: 36791720 PMCID: PMC10027443 DOI: 10.1016/j.bpj.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 01/28/2023] [Accepted: 01/31/2023] [Indexed: 02/15/2023] Open
Abstract
The formation of biomolecular condensates has emerged as a new biophysical principle for subcellular compartmentalization within cells to facilitate the spatiotemporal regulation of a multitude of complex biomolecular reactions. In this Research Highlight, we summarize the findings that were published in Biophysical Journal during the past two years (2021 and 2022). These papers provided biophysical insights into the formation of biomolecular condensates via phase separation of proteins with or without nucleic acids.
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Affiliation(s)
- Ashish Joshi
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India.
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20
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Mondal S, Baumgart T. Membrane reshaping by protein condensates. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184121. [PMID: 36642341 PMCID: PMC10208392 DOI: 10.1016/j.bbamem.2023.184121] [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: 10/20/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/15/2023]
Abstract
Proteins can organize into dynamic, functionally important assemblies on fluid membrane surfaces. Phase separation has emerged as an important mechanism for forming such protein assemblies on the membrane during cell signaling, endocytosis, and cytoskeleton regulation. Protein-protein phase separation thus adds novel fluid mosaics to the classical Singer and Nicolson model. Protein condensates formed in this process can modulate membrane morphologies. This is evident from recent reports of protein condensate-driven membrane reshaping in processes such as endocytosis, autophagosome formation, and protein storage vacuole morphogenesis in plants. Lateral phase separation (on the membrane surface) of peripheral curvature coupling proteins can modulate such membrane morphological transitions. Additionally, three-dimensional protein phase separation can result in droplets that through adhesion can affect membrane shape changes. How do these condensate-driven curvature generation mechanisms contrast with the classically recognized scaffolding and amphipathic helix insertion activities of specific membrane remodeling proteins? A salient feature of these condensate-driven membrane activities is that they depend upon both macroscopic features (such as interfacial energies of the condensate, membrane, and cytosol) as well as microscopic, molecular-level interactions (such as protein-lipid binding). This review highlights the current understanding of the mechanisms underlying curvature generation by protein condensates in various biological pathways.
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Affiliation(s)
- Samsuzzoha Mondal
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Tobias Baumgart
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States.
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21
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Boeynaems S, Chong S, Gsponer J, Holt L, Milovanovic D, Mitrea DM, Mueller-Cajar O, Portz B, Reilly JF, Reinkemeier CD, Sabari BR, Sanulli S, Shorter J, Sontag E, Strader L, Stachowiak J, Weber SC, White M, Zhang H, Zweckstetter M, Elbaum-Garfinkle S, Kriwacki R. Phase Separation in Biology and Disease; Current Perspectives and Open Questions. J Mol Biol 2023; 435:167971. [PMID: 36690068 PMCID: PMC9970028 DOI: 10.1016/j.jmb.2023.167971] [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: 12/06/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/22/2023]
Abstract
In the past almost 15 years, we witnessed the birth of a new scientific field focused on the existence, formation, biological functions, and disease associations of membraneless bodies in cells, now referred to as biomolecular condensates. Pioneering studies from several laboratories [reviewed in1-3] supported a model wherein biomolecular condensates associated with diverse biological processes form through the process of phase separation. These and other findings that followed have revolutionized our understanding of how biomolecules are organized in space and time within cells to perform myriad biological functions, including cell fate determination, signal transduction, endocytosis, regulation of gene expression and protein translation, and regulation of RNA metabolism. Further, condensates formed through aberrant phase transitions have been associated with numerous human diseases, prominently including neurodegeneration and cancer. While in some cases, rigorous evidence supports links between formation of biomolecular condensates through phase separation and biological functions, in many others such links are less robustly supported, which has led to rightful scrutiny of the generality of the roles of phase separation in biology and disease.4-7 During a week-long workshop in March 2022 at the Telluride Science Research Center (TSRC) in Telluride, Colorado, ∼25 scientists addressed key questions surrounding the biomolecular condensates field. Herein, we present insights gained through these discussions, addressing topics including, roles of condensates in diverse biological processes and systems, and normal and disease cell states, their applications to synthetic biology, and the potential for therapeutically targeting biomolecular condensates.
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Affiliation(s)
- Steven Boeynaems
- Department of Molecular and Human Genetics, Therapeutic Innovation Center (THINC), Center for Alzheimer’s and Neurodegenerative Diseases (CAND), Dan L Duncan Comprehensive Cancer Center (DLDCCC), Baylor College of Medicine, Houston, TX 77030, USA and Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX 77030, USA
| | - Shasha Chong
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Jörg Gsponer
- Michael Smith Laboratories, Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Liam Holt
- New York University School of Medicine, Institute for Systems Genetics, New York, NY 10016
| | - Drago Milovanovic
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
| | | | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | | | | | | | - Benjamin R. Sabari
- Laboratory of Nuclear Organization, Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas, TX
| | - Serena Sanulli
- Department of Genetics, Stanford University, Palo Alto, CA 94304
| | - James Shorter
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Emily Sontag
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Lucia Strader
- Department of Biology, Duke University, Durham, NC 27708 USA
| | - Jeanne Stachowiak
- University of Texas at Austin, Department of Biomedical Engineering, Austin, TX, USA
| | | | | | - Huaiying Zhang
- Department of Biological Sciences, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany; Max Planck Institute for Multidisciplinary Sciences, Department of NMR-based Structural Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Shana Elbaum-Garfinkle
- Department of Biochemistry, The Graduate Center of the City University of New York, New York, NY and Structural Biology Initiative, Advanced Science Research Center, City University of New York, New York, NY
| | - Richard Kriwacki
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee and Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, Tennessee
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22
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Wen Y, Ma J. Phase separation drives the formation of biomolecular condensates in the immune system. Front Immunol 2022; 13:986589. [PMID: 36439121 PMCID: PMC9685520 DOI: 10.3389/fimmu.2022.986589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 10/19/2022] [Indexed: 08/12/2023] Open
Abstract
When the external conditions change, such as the temperature or the pressure, the multi-component system sometimes separates into several phases with different components and structures, which is called phase separation. Increasing studies have shown that cells condense related biomolecules into independent compartments in order to carry out orderly and efficient biological reactions with the help of phase separation. Biomolecular condensates formed by phase separation play a significant role in a variety of cellular processes, including the control of signal transduction, the regulation of gene expression, and the stress response. In recent years, many phase separation events have been discovered in the immune response process. In this review, we provided a comprehensive and detailed overview of the role and mechanism of phase separation in the innate and adaptive immune responses, which will help the readers to appreciate the advance and importance of this field.
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Affiliation(s)
- Yuqing Wen
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Hunan Key Laboratory of Cancer Metabolism, Changsha, China
| | - Jian Ma
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
- Cancer Research Institute and School of Basic Medical Science, Central South University, Changsha, China
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Hunan Key Laboratory of Cancer Metabolism, Changsha, China
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23
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Mondal S, Cui Q. Coacervation of poly-electrolytes in the presence of lipid bilayers: mutual alteration of structure and morphology. Chem Sci 2022; 13:7933-7946. [PMID: 35865903 PMCID: PMC9258347 DOI: 10.1039/d2sc02013k] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
Many intrinsically disordered peptides have been shown to undergo liquid-liquid phase separation and form complex coacervates, which play various regulatory roles in the cell. Recent experimental studies found that such phase separation processes may also occur at the lipid membrane surface and help organize biomolecules during signaling events; in some cases, phase separation of proteins at the membrane surface was also observed to lead to significant remodeling of the membrane morphology. The molecular mechanisms that govern the interactions between complex coacervates and lipid membranes and the impacts of such interactions on their structure and morphology, however, remain unclear. Here we study the coacervation of poly-glutamate (E30) and poly-lysine (K30) in the presence of lipid bilayers of different compositions. We carry out explicit-solvent coarse-grained molecular dynamics simulations by using the MARTINI (v3.0) force-field. We find that more than 20% anionic lipids are required for the coacervate to form stable contact with the bilayer. Upon wetting, the coacervate induces negative curvature to the bilayer and facilitates local lipid demixing, without any peptide insertion. The magnitude of negative curvature, extent of lipid demixing, and asphericity of the coacervate increase with the concentration of anionic lipids. Overall, we observe a decrease in the number of contacts among the polyelectrolytes as the droplet spreads over the bilayer. Therefore, unlike previous suggestions, interactions among polyelectrolytes do not constitute a driving force for the membrane bending upon wetting by the coacervate. Rather, analysis of interaction energy components suggests that bending of the membrane is favored by enhanced interactions between polyelectrolytes with lipids as well as with counterions. Kinetic studies reveal that, at the studied polyelectrolyte concentrations, the coacervate formation precedes bilayer wetting.
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Affiliation(s)
- Sayantan Mondal
- Department of Chemistry, Boston University 590 Commonwealth Avenue Boston MA 02215 USA (+1)-617-353-6189
| | - Qiang Cui
- Department of Chemistry, Boston University 590 Commonwealth Avenue Boston MA 02215 USA (+1)-617-353-6189
- Department of Physics, Boston University 590 Commonwealth Avenue Boston MA 02215 USA
- Department of Biomedical Engineering, Boston University 44 Cummington Mall Boston MA 02215 USA
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24
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Chien PJ, Shih YL, Cheng CT, Tu HL. Chip assisted formation of phase-separated liposomes for reconstituting spatial protein-lipid interactions. LAB ON A CHIP 2022; 22:2540-2548. [PMID: 35667105 DOI: 10.1039/d2lc00089j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spatially organized molecular interactions are fundamental features underlying many biochemical processes in cells. These spatially defined reactions are essential to ensure high signaling specificity and are indispensable for maintaining cell functions. The construction of synthetic cell models that can resemble such properties is thus important yet less investigated. In this study, we present a reliable method for the rapid production of highly uniform phase-separated liposomes as synthetic cell models. Specifically, a microfluidics-based strategy coupled with custom reagents for generating size-tunable liposomes with various lipid compositions is presented. In addition, an important cell signaling interacting pair, the pleckstrin homology (PH) domain and PIP2 lipid, is used to demonstrate the controlled molecular assembly inside these liposomes. The result shows that PIP2 on phase-separated domains successfully recruits the PH domains to realize spatially defined molecular interactions. Such a system is versatile and can be expanded to synthesize other proteins for realizing multiplexed molecular interactions in the same liposome. Phase-separated lipid domains can also be used to recruit targeted proteins to initiate localized reactions, thus paving the way for organizing a complex signaling cascade in the synthetic cell.
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Affiliation(s)
- Po-Jen Chien
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
| | - Yi-Lun Shih
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
| | - Chieh-Teng Cheng
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taiwan
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taiwan
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25
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A two-component protein condensate of the EGFR cytoplasmic tail and Grb2 regulates Ras activation by SOS at the membrane. Proc Natl Acad Sci U S A 2022; 119:e2122531119. [PMID: 35507881 PMCID: PMC9181613 DOI: 10.1073/pnas.2122531119] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
SignificanceTwo-dimensional condensates of proteins on the membrane surface, driven by tyrosine phosphorylation, are beginning to emerge as important players in signal transduction. This work describes discovery of a protein condensation phase transition of EGFR and Grb2 on membrane surfaces, which is poised to have a significant impact on how we understand EGFR signaling and misregulation in disease. EGFR condensation is mediated through a Grb2-Grb2 crosslinking element, which itself is regulatable through a specific phosphotyrosine site on Grb2. Furthermore, the EGFR condensate exerts significant control over the ability of SOS to activate Ras, thus implicating the EGFR condensate as a regulator of signal propagation from EGFR to Ras and the MAPK pathway.
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26
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Ureña J, Knight A, Lee IH. Membrane Cargo Density-Dependent Interaction between Protein and Lipid Domains on the Giant Unilamellar Vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:4702-4712. [PMID: 35385290 DOI: 10.1021/acs.langmuir.2c00247] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Protein cargos anchored on the lipid membrane can be segregated by fluidic domain phase separation. Lipid membranes at certain compositions may separate into lipid domains to segregate cargos, and protein cargos themselves may be involved in protein condensate domain formation with multivalent binding proteins to segregate cargos. Recent studies suggest that these two driving forces of phase separation closely interact on the lipid membranes to promote codomain formation. In this report, we studied the effect of cargo density on the outcome of the cargo phase separation on giant unilamellar vesicles. Proteins and lipids are connected only by the anchored cargos, so it was originally hypothesized that higher cargo density would increase the degree of interaction between the lipid and protein domains, promoting more phase separation. However, fluorescence image analysis on different cargo densities showed that the cooperative domain formation and steric pressure are at a tug of war opposing each other. Cooperative domain formation is dominant under lower anchor density conditions, and above a threshold density, steric pressure was dominant opposing the domain formation. The result suggests that the cargo density is a key parameter affecting the outcome of cargo organization on the lipid membranes by phase separation.
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Affiliation(s)
- Juan Ureña
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
| | - Ashlynn Knight
- Department of Biology, Montclair State University, Montclair, New Jersey 07043, United States
| | - Il-Hyung Lee
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
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27
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Membrane surfaces regulate assembly of ribonucleoprotein condensates. Nat Cell Biol 2022; 24:461-470. [PMID: 35411085 PMCID: PMC9035128 DOI: 10.1038/s41556-022-00882-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/26/2022] [Accepted: 03/03/2022] [Indexed: 12/20/2022]
Abstract
Biomolecular condensates organize biochemistry, yet little is known about how cells control the position and scale of these structures. In cells, condensates often appear as relatively small assemblies that do not coarsen into a single droplet despite their propensity to fuse. Here we report that ribonucleoprotein condensates of the Q-rich protein Whi3 interact with the endoplasmic reticulum, prompting us to examine how membrane association controls condensate size. Reconstitution reveals that membrane recruitment promotes Whi3 condensation under physiological conditions. These assemblies rapidly arrest, resembling size distributions seen in cells. The temporal ordering of molecular interactions and the slow diffusion of membrane-bound complexes can limit condensate size. Our experiments reveal a tradeoff between locally-enhanced protein concentration at membranes, favoring condensation, and an accompanying reduction in diffusion, restricting coarsening. Given that many condensates bind endomembranes, we predict that the biophysical properties of lipid bilayers are key for controlling condensate sizes throughout the cell.
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28
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Abstract
Immune signalling pathways convert pathogenic stimuli into cytosolic events that lead to the resolution of infection. Upon ligand engagement, immune receptors together with their downstream adaptors and effectors undergo substantial conformational changes and spatial reorganization. During this process, nanometre-to-micrometre-sized signalling clusters have been commonly observed that are believed to be hotspots for signal transduction. Because of their large size and heterogeneous composition, it remains a challenge to fully understand the mechanisms by which these signalling clusters form and their functional consequences. Recently, phase separation has emerged as a new biophysical principle for organizing biomolecules into large clusters with fluidic properties. Although the field is still in its infancy, studies of phase separation in immunology are expected to provide new perspectives for understanding immune responses. Here, we present an up-to-date view of how liquid-liquid phase separation drives the formation of signalling condensates and regulates immune signalling pathways, including those downstream of T cell receptor, B cell receptor and the innate immune receptors cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) and retinoic acid-inducible gene I protein (RIG-I). We conclude with a summary of the current challenges the field is facing and outstanding questions for future studies.
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Affiliation(s)
- Qian Xiao
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA
| | - Ceara K. McAtee
- Yale Combined Program in the Biological and Biomedical Sciences, New Haven, CT, USA
| | - Xiaolei Su
- Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA,Yale Cancer Center, Yale University, New Haven, CT, USA,
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29
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Case LB, De Pasquale M, Henry L, Rosen MK. Synergistic phase separation of two pathways promotes integrin clustering and nascent adhesion formation. eLife 2022; 11:e72588. [PMID: 35049497 PMCID: PMC8791637 DOI: 10.7554/elife.72588] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 01/10/2022] [Indexed: 12/14/2022] Open
Abstract
Integrin adhesion complexes (IACs) are integrin-based plasma-membrane-associated compartments where cells sense environmental cues. The physical mechanisms and molecular interactions that mediate initial IAC formation are unclear. We found that both p130Cas ('Cas') and Focal adhesion kinase ('FAK') undergo liquid-liquid phase separation in vitro under physiologic conditions. Cas- and FAK- driven phase separation is sufficient to reconstitute kindlin-dependent integrin clustering in vitro with recombinant mammalian proteins. In vitro condensates and IACs in mouse embryonic fibroblasts (MEFs) exhibit similar sensitivities to environmental perturbations including changes in temperature and pH. Furthermore, mutations that inhibit or enhance phase separation in vitro reduce or increase the number of IACs in MEFs, respectively. Finally, we find that the Cas and FAK pathways act synergistically to promote phase separation, integrin clustering, IAC formation and partitioning of key components in vitro and in cells. We propose that Cas- and FAK-driven phase separation provides an intracellular trigger for integrin clustering and nascent IAC formation.
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Affiliation(s)
- Lindsay B Case
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Milagros De Pasquale
- Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Lisa Henry
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
| | - Michael K Rosen
- Department of Biophysics, Howard Hughes Medical Institute, The University of Texas Southwestern Medical CenterDallasUnited States
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30
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Kakuda S, Suresh P, Li G, London E. Loss of plasma membrane lipid asymmetry can induce ordered domain (raft) formation. J Lipid Res 2022; 63:100155. [PMID: 34843684 PMCID: PMC8953672 DOI: 10.1016/j.jlr.2021.100155] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/22/2022] Open
Abstract
In some cases, lipids in one leaflet of an asymmetric artificial lipid vesicle suppress the formation of ordered lipid domains (rafts) in the opposing leaflet. Whether this occurs in natural membranes is unknown. Here, we investigated this issue using plasma membrane vesicles (PMVs) from rat leukemia RBL-2H3 cells. Membrane domain formation and order was assessed by fluorescence resonance energy transfer and fluorescence anisotropy. We found that ordered domains in PMVs prepared from cells by N-ethyl maleimide (NEM) treatment formed up to ∼37°C, whereas ordered domains in symmetric vesicles formed from the extracted PMV lipids were stable up to 55°C, indicating the stability of ordered domains was substantially decreased in intact PMVs. This behavior paralleled lesser ordered domain stability in artificial asymmetric lipid vesicles relative to the corresponding symmetric vesicles, suggesting intact PMVs exhibit some degree of lipid asymmetry. This was supported by phosphatidylserine mislocalization on PMV outer leaflets as judged by annexin binding, which indicated NEM-induced PMVs are much more asymmetric than PMVs formed by dithiothreitol/paraformaldehyde treatment. Destroying asymmetry by reconstitution of PMVs using detergent dilution also showed stabilization of domain formation, even though membrane proteins remained associated with reconstituted vesicles. Similar domain stabilization was observed in artificial asymmetric lipid vesicles after destroying asymmetry via detergent reconstitution. Proteinase K digestion of proteins had little effect on domain stability in NEM PMVs. We conclude that loss of PMV lipid asymmetry can induce ordered domain formation. The dynamic control of lipid asymmetry in cells may regulate domain formation in plasma membranes.
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Affiliation(s)
- Shinako Kakuda
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Pavana Suresh
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Guangtao Li
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Erwin London
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA.
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31
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Shillcock JC, Thomas DB, Beaumont JR, Bragg GM, Vousden ML, Brown AD. Coupling Bulk Phase Separation of Disordered Proteins to Membrane Domain Formation in Molecular Simulations on a Bespoke Compute Fabric. MEMBRANES 2021; 12:membranes12010017. [PMID: 35054543 PMCID: PMC8779898 DOI: 10.3390/membranes12010017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 05/28/2023]
Abstract
Phospholipid membranes surround the cell and its internal organelles, and their multicomponent nature allows the formation of domains that are important in cellular signalling, the immune system, and bacterial infection. Cytoplasmic compartments are also created by the phase separation of intrinsically disordered proteins into biomolecular condensates. The ubiquity of lipid membranes and protein condensates raises the question of how three-dimensional droplets might interact with two-dimensional domains, and whether this coupling has physiological or pathological importance. Here, we explore the equilibrium morphologies of a dilute phase of a model disordered protein interacting with an ideal-mixing, two-component lipid membrane using coarse-grained molecular simulations. We find that the proteins can wet the membrane with and without domain formation, and form phase separated droplets bound to membrane domains. Results from much larger simulations performed on a novel non-von-Neumann compute architecture called POETS, which greatly accelerates their execution compared to conventional hardware, confirm the observations. Reducing the wall clock time for such simulations requires new architectures and computational techniques. We demonstrate here an inter-disciplinary approach that uses real-world biophysical questions to drive the development of new computing hardware and simulation algorithms.
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Affiliation(s)
- Julian C. Shillcock
- Blue Brain Project and Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - David B. Thomas
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK; (D.B.T.); (G.M.B.); (M.L.V.); (A.D.B.)
| | - Jonathan R. Beaumont
- Department of Electronic Engineering, Imperial College London, London SW7 2AZ, UK;
| | - Graeme M. Bragg
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK; (D.B.T.); (G.M.B.); (M.L.V.); (A.D.B.)
| | - Mark L. Vousden
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK; (D.B.T.); (G.M.B.); (M.L.V.); (A.D.B.)
| | - Andrew D. Brown
- Department of Electronics and Computer Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK; (D.B.T.); (G.M.B.); (M.L.V.); (A.D.B.)
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32
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Surface densities prewet a near-critical membrane. Proc Natl Acad Sci U S A 2021; 118:2103401118. [PMID: 34599097 DOI: 10.1073/pnas.2103401118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2021] [Indexed: 11/18/2022] Open
Abstract
Recent work has highlighted roles for thermodynamic phase behavior in diverse cellular processes. Proteins and nucleic acids can phase separate into three-dimensional liquid droplets in the cytoplasm and nucleus and the plasma membrane of animal cells appears tuned close to a two-dimensional liquid-liquid critical point. In some examples, cytoplasmic proteins aggregate at plasma membrane domains, forming structures such as the postsynaptic density and diverse signaling clusters. Here we examine the physics of these surface densities, employing minimal simulations of polymers prone to phase separation coupled to an Ising membrane surface in conjunction with a complementary Landau theory. We argue that these surface densities are a phase reminiscent of prewetting, in which a molecularly thin three-dimensional liquid forms on a usually solid surface. However, in surface densities the solid surface is replaced by a membrane with an independent propensity to phase separate. We show that proximity to criticality in the membrane dramatically increases the parameter regime in which a prewetting-like transition occurs, leading to a broad region where coexisting surface phases can form even when a bulk phase is unstable. Our simulations naturally exhibit three-surface phase coexistence even though both the membrane and the polymer bulk only display two-phase coexistence on their own. We argue that the physics of these surface densities may be shared with diverse functional structures seen in eukaryotic cells.
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33
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Loh D, Reiter RJ. Melatonin: Regulation of Biomolecular Condensates in Neurodegenerative Disorders. Antioxidants (Basel) 2021; 10:1483. [PMID: 34573116 PMCID: PMC8465482 DOI: 10.3390/antiox10091483] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that form dynamic, chemically distinct subcellular compartments organizing macromolecules such as proteins, RNA, and DNA in unicellular prokaryotic bacteria and complex eukaryotic cells. Separated from surrounding environments, MLOs in the nucleoplasm, cytoplasm, and mitochondria assemble by liquid-liquid phase separation (LLPS) into transient, non-static, liquid-like droplets that regulate essential molecular functions. LLPS is primarily controlled by post-translational modifications (PTMs) that fine-tune the balance between attractive and repulsive charge states and/or binding motifs of proteins. Aberrant phase separation due to dysregulated membrane lipid rafts and/or PTMs, as well as the absence of adequate hydrotropic small molecules such as ATP, or the presence of specific RNA proteins can cause pathological protein aggregation in neurodegenerative disorders. Melatonin may exert a dominant influence over phase separation in biomolecular condensates by optimizing membrane and MLO interdependent reactions through stabilizing lipid raft domains, reducing line tension, and maintaining negative membrane curvature and fluidity. As a potent antioxidant, melatonin protects cardiolipin and other membrane lipids from peroxidation cascades, supporting protein trafficking, signaling, ion channel activities, and ATPase functionality during condensate coacervation or dissolution. Melatonin may even control condensate LLPS through PTM and balance mRNA- and RNA-binding protein composition by regulating N6-methyladenosine (m6A) modifications. There is currently a lack of pharmaceuticals targeting neurodegenerative disorders via the regulation of phase separation. The potential of melatonin in the modulation of biomolecular condensate in the attenuation of aberrant condensate aggregation in neurodegenerative disorders is discussed in this review.
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Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, UT Health Science Center, San Antonio, TX 78229, USA
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34
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Chen Z, Oh D, Biswas KH, Zaidel-Bar R, Groves JT. Probing the effect of clustering on EphA2 receptor signaling efficiency by subcellular control of ligand-receptor mobility. eLife 2021; 10:67379. [PMID: 34414885 PMCID: PMC8397371 DOI: 10.7554/elife.67379] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 08/19/2021] [Indexed: 11/29/2022] Open
Abstract
Clustering of ligand:receptor complexes on the cell membrane is widely presumed to have functional consequences for subsequent signal transduction. However, it is experimentally challenging to selectively manipulate receptor clustering without altering other biochemical aspects of the cellular system. Here, we develop a microfabrication strategy to produce substrates displaying mobile and immobile ligands that are separated by roughly 1 µm, and thus experience an identical cytoplasmic signaling state, enabling precision comparison of downstream signaling reactions. Applying this approach to characterize the ephrinA1:EphA2 signaling system reveals that EphA2 clustering enhances both receptor phosphorylation and downstream signaling activity. Single-molecule imaging clearly resolves increased molecular binding dwell times at EphA2 clusters for both Grb2:SOS and NCK:N-WASP signaling modules. This type of intracellular comparison enables a substantially higher degree of quantitative analysis than is possible when comparisons must be made between different cells and essentially eliminates the effects of cellular response to ligand manipulation.
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Affiliation(s)
- Zhongwen Chen
- Multiscale Research Institute of Complex Systems, Fudan University, Shanghai, China.,Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Dongmyung Oh
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, United States.,Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Kabir Hassan Biswas
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Ronen Zaidel-Bar
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
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35
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Jaqaman K, Ditlev JA. Biomolecular condensates in membrane receptor signaling. Curr Opin Cell Biol 2021; 69:48-54. [PMID: 33461072 PMCID: PMC8058224 DOI: 10.1016/j.ceb.2020.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022]
Abstract
Clustering is a prominent feature of receptors at the plasma membrane (PM). It plays an important role in signaling. Liquid-liquid phase separation (LLPS) of proteins is emerging as a novel mechanism underlying the observed clustering. Receptors/transmembrane signaling proteins can be core components essential for LLPS (such as LAT or nephrin) or clients enriched at the phase-separated condensates (for example, at the postsynaptic density or at tight junctions). Condensate formation has been shown to regulate signaling in multiple ways, including by increasing protein binding avidity and by modulating the local biochemical environment. In moving forward, it is important to study protein LLPS at the PM of living cells, its interplay with other factors underlying receptor clustering, and its signaling and functional consequences.
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Affiliation(s)
- Khuloud Jaqaman
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Jonathon A Ditlev
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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36
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Kahn JD, Lemke EA, Pappu RV. Faces, facets, and functions of biomolecular condensates driven by multivalent proteins and nucleic acids. Biophys J 2021; 120:E1-E4. [PMID: 33730551 DOI: 10.1016/j.bpj.2021.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 01/17/2023] Open
Affiliation(s)
- Jason D Kahn
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland.
| | - Edward A Lemke
- Biocentre, Johannes Gutenberg University Mainz, Mainz, Germany; Institute of Molecular Biology, Mainz, Germany
| | - Rohit V Pappu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri; Center for Science & Engineering of Living Systems, Washington University in St. Louis, St. Louis, Missouri
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37
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Ditlev JA. Membrane-associated phase separation: organization and function emerge from a two-dimensional milieu. J Mol Cell Biol 2021; 13:319-324. [PMID: 33532844 PMCID: PMC8339363 DOI: 10.1093/jmcb/mjab010] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Jonathon A Ditlev
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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38
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Botterbusch S, Baumgart T. Interactions between Phase-Separated Liquids and Membrane Surfaces. APPLIED SCIENCES (BASEL, SWITZERLAND) 2021; 11:1288. [PMID: 34327010 PMCID: PMC8315427 DOI: 10.3390/app11031288] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Liquid-liquid phase separation has recently emerged as an important fundamental organizational phenomenon in biological settings. Most studies of biological phase separation have focused on droplets that "condense" from solution above a critical concentration, forming so-called "membraneless organelles" suspended in solution. However, membranes are ubiquitous throughout cells, and many biomolecular condensates interact with membrane surfaces. Such membrane-associated phase-separated systems range from clusters of integral or peripheral membrane proteins in the plane of the membrane to free, spherical droplets wetting membrane surfaces to droplets containing small lipid vesicles. In this review, we consider phase-separated liquids that interact with membrane surfaces and we discuss the consequences of those interactions. The physical properties of distinct liquid phases in contact with bilayers can reshape the membrane, and liquid-liquid phase separation can construct membrane-associated protein structures, modulate their function, and organize collections of lipid vesicles dynamically. We summarize the common phenomena that arise in these systems of liquid phases and membranes.
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