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Bartolomé-Nafría A, García-Pardo J, Ventura S. Mutations in human prion-like domains: pathogenic but not always amyloidogenic. Prion 2024; 18:28-39. [PMID: 38512820 PMCID: PMC10962614 DOI: 10.1080/19336896.2024.2329186] [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: 01/08/2024] [Accepted: 03/06/2024] [Indexed: 03/23/2024] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are multifunctional proteins with integral roles in RNA metabolism and the regulation of alternative splicing. These proteins typically contain prion-like domains of low complexity (PrLDs or LCDs) that govern their assembly into either functional or pathological amyloid fibrils. To date, over 60 mutations targeting the LCDs of hnRNPs have been identified and associated with a spectrum of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's disease (AD). The cryo-EM structures of pathological and functional fibrils formed by different hnRNPs have been recently elucidated, including those of hnRNPA1, hnRNPA2, hnRNPDL-2, TDP-43, and FUS. In this review, we discuss the structural features of these amyloid assemblies, placing particular emphasis on scrutinizing the impact of prevalent disease-associated mutations mapping within their LCDs. By performing systematic energy calculations, we reveal a prevailing trend of destabilizing effects induced by these mutations in the amyloid structure, challenging the traditionally assumed correlation between pathogenicity and amyloidogenic propensity. Understanding the molecular basis of this discrepancy might provide insights for developing targeted therapeutic strategies to combat hnRNP-associated diseases.
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Affiliation(s)
- Andrea Bartolomé-Nafría
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Javier García-Pardo
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Barcelona, Spain
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2
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Ruan K, Bai G, Fang Y, Li D, Li T, Liu X, Lu B, Lu Q, Songyang Z, Sun S, Wang Z, Zhang X, Zhou W, Zhang H. Biomolecular condensates and disease pathogenesis. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-024-2661-3. [PMID: 39037698 DOI: 10.1007/s11427-024-2661-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 06/21/2024] [Indexed: 07/23/2024]
Abstract
Biomolecular condensates or membraneless organelles (MLOs) formed by liquid-liquid phase separation (LLPS) divide intracellular spaces into discrete compartments for specific functions. Dysregulation of LLPS or aberrant phase transition that disturbs the formation or material states of MLOs is closely correlated with neurodegeneration, tumorigenesis, and many other pathological processes. Herein, we summarize the recent progress in development of methods to monitor phase separation and we discuss the biogenesis and function of MLOs formed through phase separation. We then present emerging proof-of-concept examples regarding the disruption of phase separation homeostasis in a diverse array of clinical conditions including neurodegenerative disorders, hearing loss, cancers, and immunological diseases. Finally, we describe the emerging discovery of chemical modulators of phase separation.
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Affiliation(s)
- Ke Ruan
- The First Affiliated Hospital & School of Life Sciences, Ministry of Education Key Laboratory for Membrane-less Organelles & Cellular Dynamics, Hefei National Research Center for Interdisciplinary Sciences at the Microscale, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230027, China.
| | - Ge Bai
- Nanhu Brain-computer Interface Institute, Hangzhou, 311100, China.
- Department of Neurology of Second Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Tingting Li
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
| | - Xingguo Liu
- CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
- Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, 510000, China.
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, School of Life Sciences, Fudan University, Shanghai, 200433, China.
| | - Qing Lu
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Zhou Songyang
- State Key Laboratory of Biocontrol, MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Shuguo Sun
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Zheng Wang
- The Second Affiliated Hospital, School of Basic Medical Sciences, Institute of Biomedical Innovation, Jiangxi Medical College, Nanchang University, Nanchang, 330031, China.
| | - Xin Zhang
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, 310024, China.
| | - Wen Zhou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
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3
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Tsoi PS, Ferreon JC, Ferreon ACM. Initiation of hnRNPA1 Low-Complexity Domain Condensation Monitored by Dynamic Light Scattering. Int J Mol Sci 2024; 25:6825. [PMID: 38999934 PMCID: PMC11241569 DOI: 10.3390/ijms25136825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/14/2024] [Accepted: 06/18/2024] [Indexed: 07/14/2024] Open
Abstract
Biomolecular condensates (BMCs) exhibit physiological and pathological relevance in biological systems. Both liquid and solid condensates play significant roles in the spatiotemporal regulation and organization of macromolecules and their biological activities. Some pathological solid condensates, such as Lewy Bodies and other fibrillar aggregates, have been hypothesized to originate from liquid condensates. With the prevalence of BMCs having functional and dysfunctional roles, it is imperative to understand the mechanism of biomolecular condensate formation and initiation. Using the low-complexity domain (LCD) of heterogenous ribonuclear protein A1 (hnRNPA1) as our model, we monitored initial assembly events using dynamic light scattering (DLS) while modulating pH and salt conditions to perturb macromolecule and condensate properties. We observed the formation of nanometer-sized BMCs (nano-condensates) distinct from protein monomers and micron-sized condensates. We also observed that conditions that solubilize micron-sized protein condensates do not solubilize nano-condensates, indicating that the balance of forces that stabilize nano-condensates and micron-sized condensates are distinct. These findings provide insight into the forces that drive protein phase separation and potential nucleation structures of macromolecular condensation.
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Affiliation(s)
| | - Josephine C. Ferreon
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Allan Chris M. Ferreon
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
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4
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Fang M, Liu Y, Huang C, Fan S. Targeting stress granules in neurodegenerative diseases: A focus on biological function and dynamics disorders. Biofactors 2024; 50:422-438. [PMID: 37966813 DOI: 10.1002/biof.2017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/26/2023] [Indexed: 11/16/2023]
Abstract
Stress granules (SGs) are membraneless organelles formed by eukaryotic cells in response to stress to promote cell survival through their pleiotropic cytoprotective effects. SGs recruit a variety of components to enhance their physiological function, and play a critical role in the propagation of pathological proteins, a key factor in neurodegeneration. Recent advances indicate that SG dynamic disorders exacerbate neuronal susceptibility to stress in neurodegenerative diseases (NDs) including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Huntington's disease (HD) and Parkinson's disease (PD). Here, we outline the biological functions of SGs, highlight SG dynamic disorders in NDs, and emphasize therapeutic approaches for enhancing SG dynamics to provide new insights into ND intervention.
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Affiliation(s)
- Minglv Fang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ying Liu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Cheng Huang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shengjie Fan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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5
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Verma SK, Kuyumcu-Martinez MN. RNA binding proteins in cardiovascular development and disease. Curr Top Dev Biol 2024; 156:51-119. [PMID: 38556427 DOI: 10.1016/bs.ctdb.2024.01.007] [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] [Indexed: 04/02/2024]
Abstract
Congenital heart disease (CHD) is the most common birth defect affecting>1.35 million newborn babies worldwide. CHD can lead to prenatal, neonatal, postnatal lethality or life-long cardiac complications. RNA binding protein (RBP) mutations or variants are emerging as contributors to CHDs. RBPs are wizards of gene regulation and are major contributors to mRNA and protein landscape. However, not much is known about RBPs in the developing heart and their contributions to CHD. In this chapter, we will discuss our current knowledge about specific RBPs implicated in CHDs. We are in an exciting era to study RBPs using the currently available and highly successful RNA-based therapies and methodologies. Understanding how RBPs shape the developing heart will unveil their contributions to CHD. Identifying their target RNAs in the embryonic heart will ultimately lead to RNA-based treatments for congenital heart disease.
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Affiliation(s)
- Sunil K Verma
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine Charlottesville, VA, United States.
| | - Muge N Kuyumcu-Martinez
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine Charlottesville, VA, United States; Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA, United States; University of Virginia Cancer Center, Charlottesville, VA, United States.
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6
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Garcia-Pardo J, Ventura S. Cryo-EM structures of functional and pathological amyloid ribonucleoprotein assemblies. Trends Biochem Sci 2024; 49:119-133. [PMID: 37926650 DOI: 10.1016/j.tibs.2023.10.005] [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: 07/26/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 11/07/2023]
Abstract
Amyloids are implicated in neurodegenerative and systemic diseases, yet they serve important functional roles in numerous organisms. Heterogeneous nuclear ribonucleoproteins (hnRNPs) represent a large family of RNA-binding proteins (RBPs) that control central events of RNA biogenesis in normal and diseased cellular conditions. Many of these proteins contain prion-like sequences of low complexity, which not only assemble into functional fibrils in response to cellular cues but can also lead to disease when missense mutations arise in their sequences. Recent advances in cryo-electron microscopy (cryo-EM) have provided unprecedented high-resolution structural insights into diverse amyloid assemblies formed by hnRNPs and structurally related RBPs, including TAR DNA-binding protein 43 (TDP-43), Fused in Sarcoma (FUS), Orb2, hnRNPA1, hnRNPA2, and hnRNPDL-2. This review provides a comprehensive overview of these structures and explores their functional and pathological implications.
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Affiliation(s)
- Javier Garcia-Pardo
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina (IBB) and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
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7
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Ling X, Yao Y, Ding L, Ma J. The mechanism of UP1 binding and unfolding of human telomeric DNA G-quadruplex. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194985. [PMID: 37717939 DOI: 10.1016/j.bbagrm.2023.194985] [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: 04/11/2023] [Revised: 08/17/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023]
Abstract
The human telomere contains multiple copies of the DNA sequence d(TTAGGG) which can fold into higher order intramolecular G-quadruplexes and regulate the maintenance of telomere length and chromosomal integrity. The nucleic acid binding protein heteronuclear ribonucleoprotein A1 (hnRNP A1) and its N-terminus proteolytic product UP1 have been shown to efficiently bind and unfold telomeric DNA G-quadruplex. However, the understanding of the molecular mechanism of the UP1 binding and unfolding telomeric G-quadruplexes is still limited. Here, we performed biochemical and biophysical characterizations of UP1 binding and unfolding of human telomeric DNA G-quadruplex d[AGGG(TTAGGG)3], and in combination of systematic site-direct mutagenesis of two tandem RNA recognition motifs (RRMs) in UP1, revealed that RRM1 is responsible for initial binding and unfolding, whereas RRM2 assists RRM1 to complete the unfolding of G-quadruplex. Isothermal titration calorimetry (ITC) and circular dichroism (CD) studies of the interactions between UP1 and DNA G-quadruplex variants indicate that the "TAG" binding motif in Loop2 of telomeric G-quadruplex is critical for UP1 recognition and G-quadruplex unfolding initiation. Together we depict a model for molecular mechanism of hnRNP A1 (UP1) binding and unfolding of the human telomeric DNA G-quadruplex.
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Affiliation(s)
- Xiaobin Ling
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yuqi Yao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Lei Ding
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China.
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8
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Foressi NN, Rodríguez LC, Celej MS. Heterotypic liquid-liquid phase separation of tau and α-synuclein: Implications for overlapping neuropathologies. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140950. [PMID: 37574035 DOI: 10.1016/j.bbapap.2023.140950] [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: 06/08/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
Tauopathies and synucleinopathies are characterized by the aggregation of Tau and α-synuclein (AS) into amyloid structures, respectively. Individuals with these neuropathies have an elevated risk of developing subsequent neurodegenerative or comorbid disorders. Intriguingly, post-mortem brain examinations have revealed co-localization of Tau and AS aggregates, suggesting a synergistic pathological relationship with an adverse prognosis. The role of liquid-liquid phase separation (LLPS) in the development of neurodegenerative diseases is currently receiving significant attention, as it can contribute to the aggregation and co-deposition of amyloidogenic proteins. In this study, we investigated the phase separation behavior of Tau and AS under various insults, some of which are implicated in disease progression. Our findings demonstrate the formation of heterotypic droplets composed of Tau and AS at physiologically relevant mole ratios that mimic neurons' soma and terminal buttons. Importantly, these heterotypic droplets exhibit increased resistance to electrostatic screening compared to homotypic condensates. Moreover, we observed that biologically relevant biomolecules, known to be dysregulated in disease, exert different effects on these droplets. Additionally, we provide evidence that phase separation itself influences the amyloid aggregation of Tau and AS, underscoring the significance of this process in the development of aggregopathies.
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Affiliation(s)
- Nahuel N Foressi
- Departamento de Química Biológica Ranwel Caputto, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Leandro Cruz Rodríguez
- Departamento de Química Biológica Ranwel Caputto, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - M Soledad Celej
- Departamento de Química Biológica Ranwel Caputto, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
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9
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Blazquez S, Sanchez‐Burgos I, Ramirez J, Higginbotham T, Conde MM, Collepardo‐Guevara R, Tejedor AR, Espinosa JR. Location and Concentration of Aromatic-Rich Segments Dictates the Percolating Inter-Molecular Network and Viscoelastic Properties of Ageing Condensates. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207742. [PMID: 37386790 PMCID: PMC10477902 DOI: 10.1002/advs.202207742] [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: 12/30/2022] [Revised: 05/03/2023] [Indexed: 07/01/2023]
Abstract
Maturation of functional liquid-like biomolecular condensates into solid-like aggregates has been linked to the onset of several neurodegenerative disorders. Low-complexity aromatic-rich kinked segments (LARKS) contained in numerous RNA-binding proteins can promote aggregation by forming inter-protein β-sheet fibrils that accumulate over time and ultimately drive the liquid-to-solid transition of the condensates. Here, atomistic molecular dynamics simulations are combined with sequence-dependent coarse-grained models of various resolutions to investigate the role of LARKS abundance and position within the amino acid sequence in the maturation of condensates. Remarkably, proteins with tail-located LARKS display much higher viscosity over time than those in which the LARKS are placed toward the center. Yet, at very long timescales, proteins with a single LARKS-independently of its location-can still relax and form high viscous liquid condensates. However, phase-separated condensates of proteins containing two or more LARKS become kinetically trapped due to the formation of percolated β-sheet networks that display gel-like behavior. Furthermore, as a work case example, they demonstrate how shifting the location of the LARKS-containing low-complexity domain of FUS protein toward its center effectively precludes the accumulation of β-sheet fibrils in FUS-RNA condensates, maintaining functional liquid-like behavior without ageing.
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Affiliation(s)
- Samuel Blazquez
- Department of Physical‐ChemistryUniversidad Complutense de MadridAv. Complutense s/nMadrid28040Spain
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
| | - Ignacio Sanchez‐Burgos
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
| | - Jorge Ramirez
- Department of Chemical EngineeringUniversidad Politécnica de MadridJosé Gutiérrez Abascal 2Madrid28006Spain
| | - Tim Higginbotham
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
| | - Maria M. Conde
- Department of Chemical EngineeringUniversidad Politécnica de MadridJosé Gutiérrez Abascal 2Madrid28006Spain
| | - Rosana Collepardo‐Guevara
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
- Yusuf Hamied Department of ChemistryUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Department of GeneticsUniversity of CambridgeCambridgeCB2 3EH, UK
| | - Andres R. Tejedor
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
- Department of Chemical EngineeringUniversidad Politécnica de MadridJosé Gutiérrez Abascal 2Madrid28006Spain
| | - Jorge R. Espinosa
- Department of Physical‐ChemistryUniversidad Complutense de MadridAv. Complutense s/nMadrid28040Spain
- Maxwell Centre, Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AvenueCambridgeCB3 0HEUK
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10
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Wang WJ, Tan CP, Mao ZW. Metals and inorganic molecules in regulating protein and nucleic acid phase separation. Curr Opin Chem Biol 2023; 74:102308. [PMID: 37088005 DOI: 10.1016/j.cbpa.2023.102308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 04/25/2023]
Abstract
The realization that liquid-liquid phase separation (LLPS) underlies the formation of membraneless compartments in cells has motivated efforts to modulate the condensation process of biomolecules. Increasing evidence shows that metals and inorganic molecules abundantly distributed in cells play important roles in the regulation of biomolecular condensation. Herein, we briefly reviewed the background of biomacromolecular phase separation and summarized the recent research progress on the roles of metals and inorganic molecules in regulating protein and nucleic acid phase separation in vitro and in cells.
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Affiliation(s)
- Wen-Jin Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China.
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, PR China.
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11
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Pintado-Grima C, Santos J, Iglesias V, Manglano-Artuñedo Z, Pallarès I, Ventura S. Exploring cryptic amyloidogenic regions in prion-like proteins from plants. FRONTIERS IN PLANT SCIENCE 2023; 13:1060410. [PMID: 36726678 PMCID: PMC9885169 DOI: 10.3389/fpls.2022.1060410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
Prion-like domains (PrLDs) are intrinsically disordered regions (IDRs) of low sequence complexity with a similar composition to yeast prion domains. PrLDs-containing proteins have been involved in different organisms' regulatory processes. Regions of moderate amyloid propensity within IDRs have been shown to assemble autonomously into amyloid fibrils. These sequences tend to be rich in polar amino acids and often escape from the detection of classical bioinformatics screenings that look for highly aggregation-prone hydrophobic sequence stretches. We defined them as cryptic amyloidogenic regions (CARs) and recently developed an integrated database that collects thousands of predicted CARs in IDRs. CARs seem to be evolutionary conserved among disordered regions because of their potential to stablish functional contacts with other biomolecules. Here we have focused on identifying and characterizing CARs in prion-like proteins (pCARs) from plants, a lineage that has been poorly studied in comparison with other prionomes. We confirmed the intrinsic amyloid potential for a selected pCAR from Arabidopsis thaliana and explored functional enrichments and compositional bias of pCARs in plant prion-like proteins.
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Affiliation(s)
- Carlos Pintado-Grima
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jaime Santos
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Valentín Iglesias
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
- Barcelona Institute for Global Health, Barcelona Centre for International Health Research (ISGlobal, Hospital Clínic-Universitat de Barcelona), Barcelona, Spain
- Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Zoe Manglano-Artuñedo
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Irantzu Pallarès
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Salvador Ventura
- Departament de Bioquímica i Biologia Molecular, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
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12
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Quan MD, Liao SCJ, Ferreon JC, Ferreon ACM. Fluorescence Lifetime Imaging Microscopy of Biomolecular Condensates. Methods Mol Biol 2023; 2563:135-148. [PMID: 36227471 DOI: 10.1007/978-1-0716-2663-4_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Biomolecular condensates of ribonucleoproteins (RNPs) such as the transactivation response element (TAR) DNA-binding protein 43 (TDP-43) arise from liquid-liquid phase separation (LLPS) and play vital roles in various biological processes including the formation-dissolution of stress granules (SGs). These condensates are thought to be directly linked to neurodegenerative diseases, providing a depot of aggregation-prone proteins and serving as a cauldron of protein aggregation and fibrillation. Despite recent research efforts, biochemical processes and rearrangements within biomolecular condensates that trigger subsequent protein misfolding and aggregation remain to be elucidated. Fluorescence lifetime imaging microscopy (FLIM) provides a minimally intrusive high-sensitivity and high-resolution imaging method to monitor in-droplet spatiotemporal changes that initiate and lead to protein aggregation. In this chapter, we describe a FLIM application for characterizing chemical chaperone-assisted decoupling of TDP-43 liquid-liquid phase separation and aggregation/fibrillation, highlighting potential therapeutic strategies to combat pathological RNP-associated aggregates without compromising cellular stress responses.
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Affiliation(s)
- My Diem Quan
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA
| | | | - Josephine C Ferreon
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA.
| | - Allan Chris M Ferreon
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA.
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Laghmach R, Malhotra I, Potoyan DA. Multiscale Modeling of Protein-RNA Condensation in and Out of Equilibrium. Methods Mol Biol 2023; 2563:117-133. [PMID: 36227470 PMCID: PMC11186142 DOI: 10.1007/978-1-0716-2663-4_5] [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] [Indexed: 06/16/2023]
Abstract
A vast number of intracellular membraneless bodies also known as biomolecular condensates form through a liquid-liquid phase separation (LLPS) of biomolecules. To date, phase separation has been identified as the main driving force for a membraneless organelles such as nucleoli, Cajal bodies, stress granules, and chromatin compartments. Recently, the protein-RNA condensation is receiving increased attention, because it is closely related to the biological function of cells such as transcription, translation, and RNA metabolism. Despite the multidisciplinary efforts put forth to study the biophysical properties of protein-RNA condensates, there are many fundamental unanswered questions regarding the mechanism of formation and regulation of protein-RNA condensates in eukaryotic cells. Major challenges in studying protein-RNA condensation stem from (i) the molecular heterogeneity and conformational flexibility of RNA and protein chains and (ii) the nonequilibrium nature of transcription and cellular environment. Computer simulations, bioinformatics, and mathematical models are uniquely positioned for shedding light on the microscopic nature of protein-RNA phase separation. To this end, there is an urgent need for innovative models with the right spatiotemporal resolution for confronting the experimental observables in a comprehensive and physics-based manner. In this chapter, we will summarize the currently emerging research efforts, which employ atomistic and coarse-grained molecular models and field theoretical models to understand equilibrium and nonequilibrium aspects of protein-RNA condensation.
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Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Isha Malhotra
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, IA, USA.
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14
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Biological soft matter: intrinsically disordered proteins in liquid-liquid phase separation and biomolecular condensates. Essays Biochem 2022; 66:831-847. [PMID: 36350034 DOI: 10.1042/ebc20220052] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/10/2022]
Abstract
The facts that many proteins with crucial biological functions do not have unique structures and that many biological processes are compartmentalized into the liquid-like biomolecular condensates, which are formed via liquid-liquid phase separation (LLPS) and are not surrounded by the membrane, are revolutionizing the modern biology. These phenomena are interlinked, as the presence of intrinsic disorder represents an important requirement for a protein to undergo LLPS that drives biogenesis of numerous membrane-less organelles (MLOs). Therefore, one can consider these phenomena as crucial constituents of a new IDP-LLPS-MLO field. Furthermore, intrinsically disordered proteins (IDPs), LLPS, and MLOs represent a clear link between molecular and cellular biology and soft matter and condensed soft matter physics. Both IDP and LLPS/MLO fields are undergoing explosive development and generate the ever-increasing mountain of crucial data. These new data provide answers to so many long-standing questions that it is difficult to imagine that in the very recent past, protein scientists and cellular biologists operated without taking these revolutionary concepts into account. The goal of this essay is not to deliver a comprehensive review of the IDP-LLPS-MLO field but to provide a brief and rather subjective outline of some of the recent developments in these exciting fields.
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15
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Di Liegro CM, Schiera G, Schirò G, Di Liegro I. RNA-Binding Proteins as Epigenetic Regulators of Brain Functions and Their Involvement in Neurodegeneration. Int J Mol Sci 2022; 23:ijms232314622. [PMID: 36498959 PMCID: PMC9739182 DOI: 10.3390/ijms232314622] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
A central aspect of nervous system development and function is the post-transcriptional regulation of mRNA fate, which implies time- and site-dependent translation, in response to cues originating from cell-to-cell crosstalk. Such events are fundamental for the establishment of brain cell asymmetry, as well as of long-lasting modifications of synapses (long-term potentiation: LTP), responsible for learning, memory, and higher cognitive functions. Post-transcriptional regulation is in turn dependent on RNA-binding proteins that, by recognizing and binding brief RNA sequences, base modifications, or secondary/tertiary structures, are able to control maturation, localization, stability, and translation of the transcripts. Notably, most RBPs contain intrinsically disordered regions (IDRs) that are thought to be involved in the formation of membrane-less structures, probably due to liquid-liquid phase separation (LLPS). Such structures are evidenced as a variety of granules that contain proteins and different classes of RNAs. The other side of the peculiar properties of IDRs is, however, that, under altered cellular conditions, they are also prone to form aggregates, as observed in neurodegeneration. Interestingly, RBPs, as part of both normal and aggregated complexes, are also able to enter extracellular vesicles (EVs), and in doing so, they can also reach cells other than those that produced them.
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Affiliation(s)
- Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Giuseppe Schirò
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
- Correspondence: ; Tel.: +39-091-238-97 (ext. 415/446)
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16
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Liquid-Liquid Phase Separation Promotes Protein Aggregation and Its Implications in Ferroptosis in Parkinson’s Disease Dementia. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7165387. [PMID: 36246407 PMCID: PMC9560807 DOI: 10.1155/2022/7165387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/07/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022]
Abstract
The pathological features of PDD are represented by dopaminergic neuronal death and intracellular α-synuclein (α-syn) aggregation. The interaction of iron accumulation with α-syn and tau was further explored as an essential pathological mechanism of PDD. However, the links and mechanisms between these factors remain unclear. Studies have shown that the occurrence and development of neurodegenerative diseases such as PDD are closely related to the separation of abnormal phases. Substances such as proteins can form droplets through liquid-liquid phase separation (LLPS) under normal physiological conditions and even undergo further liquid-solid phase transitions to form solid aggregates under disease or regulatory disorders, leading to pathological phenomena. By analyzing the existing literature, we propose that LLPS is the crucial mechanism causing abnormal accumulation of α-syn, tau, and other proteins in PDD, and its interaction with iron metabolism disorder is the key factor driving ferroptosis in PDD. Therefore, we believe that LLPS can serve as one of the means to explain the pathological mechanism of PDD. Determining the significance of LLPS in neurodegenerative diseases such as PDD will stimulate interest in research into treatments based on interference with abnormal LLPS.
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17
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Tejedor AR, Sanchez-Burgos I, Estevez-Espinosa M, Garaizar A, Collepardo-Guevara R, Ramirez J, Espinosa JR. Protein structural transitions critically transform the network connectivity and viscoelasticity of RNA-binding protein condensates but RNA can prevent it. Nat Commun 2022; 13:5717. [PMID: 36175408 PMCID: PMC9522849 DOI: 10.1038/s41467-022-32874-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 08/18/2022] [Indexed: 12/03/2022] Open
Abstract
Biomolecular condensates, some of which are liquid-like during health, can age over time becoming gel-like pathological systems. One potential source of loss of liquid-like properties during ageing of RNA-binding protein condensates is the progressive formation of inter-protein β-sheets. To bridge microscopic understanding between accumulation of inter-protein β-sheets over time and the modulation of FUS and hnRNPA1 condensate viscoelasticity, we develop a multiscale simulation approach. Our method integrates atomistic simulations with sequence-dependent coarse-grained modelling of condensates that exhibit accumulation of inter-protein β-sheets over time. We reveal that inter-protein β-sheets notably increase condensate viscosity but does not transform the phase diagrams. Strikingly, the network of molecular connections within condensates is drastically altered, culminating in gelation when the network of strong β-sheets fully percolates. However, high concentrations of RNA decelerate the emergence of inter-protein β-sheets. Our study uncovers molecular and kinetic factors explaining how the accumulation of inter-protein β-sheets can trigger liquid-to-solid transitions in condensates, and suggests a potential mechanism to slow such transitions down. In this work the authors propose a multiscale computational approach, integrating atomistic and coarse-grained models simulations, to study the thermodynamic and kinetic factors playing a major role in the liquid-to-solid transition of biomolecular condensates. It is revealed how the gradual accumulation of inter-protein β-sheets increases the viscosity of functional liquid-like condensates, transforming them into gel-like pathological aggregates, and it is also shown how high concentrations of RNA can decelerate such transition.
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Affiliation(s)
- Andres R Tejedor
- Department of Chemical Engineering, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006, Madrid, Spain.,Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Ignacio Sanchez-Burgos
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Maria Estevez-Espinosa
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK.,Department of Biochemistry, University College London, Gower Street, London, WC1E 6BT, UK
| | - Adiran Garaizar
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Rosana Collepardo-Guevara
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK.,Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.,Department of Genetics, University of Cambridge, Cambridge, CB2 3EH, UK
| | - Jorge Ramirez
- Department of Chemical Engineering, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006, Madrid, Spain.
| | - Jorge R Espinosa
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK.
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18
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Li Z, Liu X, Liu M. Stress Granule Homeostasis, Aberrant Phase Transition, and Amyotrophic Lateral Sclerosis. ACS Chem Neurosci 2022; 13:2356-2370. [PMID: 35905138 DOI: 10.1021/acschemneuro.2c00262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. In recent years, a large number of ALS-related mutations have been discovered to have a strong link to stress granules (SGs). SGs are cytoplasmic ribonucleoprotein condensates mediated by liquid-liquid phase separation (LLPS) of biomacromolecules. They help cells cope with stress. The normal physiological functions of SGs are dependent on three key aspects of SG "homeostasis": SG assembly, disassembly, and SG components. Any of these three aspects can be disrupted, resulting in abnormalities in the cellular stress response and leading to cytotoxicity. Several ALS-related pathogenic mutants have abnormal LLPS abilities that disrupt SG homeostasis, and some of them can even cause aberrant phase transitions. As a result, ALS-related mutants may disrupt various aspects of SG homeostasis by directly disturbing the intermolecular interactions or affecting core SG components, thus disrupting the phase equilibrium of the cytoplasm during stress. Considering that the importance of the "global view" of SG homeostasis in ALS pathogenesis has not received enough attention, we first systematically summarize the physiological regulatory mechanism of SG homeostasis based on LLPS and then examine ALS pathogenesis from the perspective of disrupted SG homeostasis and aberrant phase transition of biomacromolecules.
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Affiliation(s)
- Zhanxu Li
- Xiangya School of Medicine, Central South University, Changsha 410078, Hunan, China
| | - Xionghao Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China
| | - Mujun Liu
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
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19
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Molecular mechanism for the synchronized electrostatic coacervation and co-aggregation of alpha-synuclein and tau. Nat Commun 2022; 13:4586. [PMID: 35933508 PMCID: PMC9357037 DOI: 10.1038/s41467-022-32350-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 07/26/2022] [Indexed: 01/05/2023] Open
Abstract
Amyloid aggregation of α-synuclein (αS) is the hallmark of Parkinson’s disease and other synucleinopathies. Recently, Tau protein, generally associated with Alzheimer’s disease, has been linked to αS pathology and observed to co-localize in αS-rich disease inclusions, although the molecular mechanisms for the co-aggregation of both proteins remain elusive. We report here that αS phase-separates into liquid condensates by electrostatic complex coacervation with positively charged polypeptides such as Tau. Condensates undergo either fast gelation or coalescence followed by slow amyloid aggregation depending on the affinity of αS for the poly-cation and the rate of valence exhaustion of the condensate network. By combining a set of advanced biophysical techniques, we have been able to characterize αS/Tau liquid-liquid phase separation and identified key factors that lead to the formation of hetero-aggregates containing both proteins in the interior of the liquid protein condensates. Here, the authors report that α-synuclein phase-separates into liquid condensates with positively charged polypeptides such as Tau. The condensates undergo different maturation processes, including the formation of α-synuclein/Tau amyloid hetero-aggregates inside the condensates.
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20
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In-Silico Analysis of pH-Dependent Liquid-Liquid Phase Separation in Intrinsically Disordered Proteins. Biomolecules 2022; 12:biom12070974. [PMID: 35883530 PMCID: PMC9313257 DOI: 10.3390/biom12070974] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/06/2022] [Accepted: 07/08/2022] [Indexed: 02/04/2023] Open
Abstract
Intrinsically disordered proteins (IDPs) are essential players in the assembly of biomolecular condensates during liquid–liquid phase separation (LLPS). Disordered regions (IDRs) are significantly exposed to the solvent and, therefore, highly influenced by fluctuations in the microenvironment. Extrinsic factors, such as pH, modify the solubility and disorder state of IDPs, which in turn may impact the formation of liquid condensates. However, little attention has been paid to how the solution pH influences LLPS, despite knowing that this process is context-dependent. Here, we have conducted a large-scale in-silico analysis of pH-dependent solubility and disorder in IDRs known to be involved in LLPS (LLPS-DRs). We found that LLPS-DRs present maximum solubility around physiological pH, where LLPS often occurs, and identified significant differences in solubility and disorder between proteins that can phase-separate by themselves or those that require a partner. We also analyzed the effect of mutations in the resulting solubility profiles of LLPS-DRs and discussed how, as a general trend, LLPS-DRs display physicochemical properties that permit their LLPS at physiologically relevant pHs.
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21
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Ectopic biomolecular phase transitions: fusion proteins in cancer pathologies. Trends Cell Biol 2022; 32:681-695. [PMID: 35484036 PMCID: PMC9288518 DOI: 10.1016/j.tcb.2022.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/13/2022] [Accepted: 03/18/2022] [Indexed: 12/22/2022]
Abstract
Biomolecular condensates are membraneless organelles (MLOs) that are enriched in specific proteins and nucleic acids, compartmentalized to perform biochemical functions. Such condensates are formed by phase separation (PS) enabled by protein domains that allow multivalent interactions. Chromosomal translocation-derived in-frame gene fusions often generate proteins with non-native domain combinations that rewire protein-protein interaction networks. Several recent studies have shown that, for a subset of these fusion proteins, pathogenesis can be driven by the ability of the fusion protein to undergo phase transitions at non-physiological cellular locations to form ectopic condensates. We highlight how such ectopic phase transitions can alter biological processes and posit that dysfunction via protein PS at non-physiological locations represents a generic route to oncogenic transformation.
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22
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Abstract
The 14-3-3 family proteins are vital scaffold proteins that ubiquitously expressed in various tissues. They interact with numerous protein targets and mediate many cellular signaling pathways. The 14-3-3 binding motifs are often embedded in intrinsically disordered regions which are closely associated with liquid-liquid phase separation (LLPS). In the past ten years, LLPS has been observed for a variety of proteins and biological processes, indicating that LLPS plays a fundamental role in the formation of membraneless organelles and cellular condensates. While extensive investigations have been performed on 14-3-3 proteins, its involvement in LLPS is overlooked. To date, 14-3-3 proteins have not been reported to undergo LLPS alone or regulate LLPS of their binding partners. To reveal the potential involvement of 14-3-3 proteins in LLPS, in this review, we summarized the LLPS propensity of 14-3-3 binding partners and found that about one half of them may undergo LLPS spontaneously. We further analyzed the phase separation behavior of representative 14-3-3 binders and discussed how 14-3-3 proteins may be involved. By modulating the conformation and valence of interactions and recruiting other molecules, we speculate that 14-3-3 proteins can efficiently regulate the functions of their targets in the context of LLPS. Considering the critical roles of 14-3-3 proteins, there is an urgent need for investigating the involvement of 14-3-3 proteins in the phase separation process of their targets and the underling mechanisms.
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23
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Yoneda R, Ueda N, Kurokawa R. m 6A Modified Short RNA Fragments Inhibit Cytoplasmic TLS/FUS Aggregation Induced by Hyperosmotic Stress. Int J Mol Sci 2021; 22:ijms222011014. [PMID: 34681673 PMCID: PMC8539258 DOI: 10.3390/ijms222011014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/08/2021] [Accepted: 10/08/2021] [Indexed: 12/24/2022] Open
Abstract
Translocated in LipoSarcoma/Fused in Sarcoma (TLS/FUS) is a nuclear RNA binding protein whose mutations cause amyotrophic lateral sclerosis. TLS/FUS undergoes LLPS and forms membraneless particles with other proteins and nucleic acids. Interaction with RNA alters conformation of TLS/FUS, which affects binding with proteins, but the effect of m6A RNA modification on the TLS/FUS–RNA interaction remains elusive. Here, we investigated the binding specificity of TLS/FUS to m6A RNA fragments by RNA pull down assay, and elucidated that both wild type and ALS-related TLS/FUS mutants strongly bound to m6A modified RNAs. TLS/FUS formed cytoplasmic foci by treating hyperosmotic stress, but the cells transfected with m6A-modified RNAs had a smaller number of foci. Moreover, m6A-modified RNA transfection resulted in the cells obtaining higher resistance to the stress. In summary, we propose TLS/FUS as a novel candidate of m6A recognition protein, and m6A-modified RNA fragments diffuse cytoplasmic TLS/FUS foci and thereby enhance cell viability.
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24
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Tsoi PS, Quan MD, Choi KJ, Dao KM, Ferreon JC, Ferreon ACM. Electrostatic modulation of hnRNPA1 low-complexity domain liquid-liquid phase separation and aggregation. Protein Sci 2021; 30:1408-1417. [PMID: 33982369 DOI: 10.1002/pro.4108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022]
Abstract
Membrane-less organelles and RNP granules are enriched in RNA and RNA-binding proteins containing disordered regions. Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), a key regulating protein in RNA metabolism, localizes to cytoplasmic RNP granules including stress granules. Dysfunctional nuclear-cytoplasmic transport and dynamic phase separation of hnRNPA1 leads to abnormal amyloid aggregation and neurodegeneration. The intrinsically disordered C-terminal domain (CTD) of hnRNPA1 mediates both dynamic liquid-liquid phase separation (LLPS) and aggregation. While cellular phase separation drives the formation of membrane-less organelles, aggregation within phase-separated compartments has been linked to neurodegenerative diseases. To understand some of the underlying mechanisms behind protein phase separation and LLPS-mediated aggregation, we studied LLPS of hnRNPA1 CTD in conditions that probe protein electrostatics, modulated specifically by varying pH conditions, and protein, salt and RNA concentrations. In the conditions investigated, we observed LLPS to be favored in acidic conditions, and by high protein, salt and RNA concentrations. We also observed that conditions that favor LLPS also enhance protein aggregation and fibrillation, which suggests an aggregation pathway that is LLPS-mediated. The results reported here also suggest that LLPS can play a direct role in facilitating protein aggregation, and that changes in cellular environment that affect protein electrostatics can contribute to the pathological aggregation exhibited in neurodegeneration.
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Affiliation(s)
- Phoebe S Tsoi
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - My Diem Quan
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Kyoung-Jae Choi
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Khoa M Dao
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Josephine C Ferreon
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Allan Chris M Ferreon
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
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