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Emmanouilidis L, Bartalucci E, Kan Y, Ijavi M, Pérez ME, Afanasyev P, Boehringer D, Zehnder J, Parekh SH, Bonn M, Michaels TCT, Wiegand T, Allain FHT. A solid beta-sheet structure is formed at the surface of FUS droplets during aging. Nat Chem Biol 2024; 20:1044-1052. [PMID: 38467846 PMCID: PMC11288893 DOI: 10.1038/s41589-024-01573-w] [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: 05/26/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024]
Abstract
Phase transitions are important to understand cell dynamics, and the maturation of liquid droplets is relevant to neurodegenerative disorders. We combined NMR and Raman spectroscopies with microscopy to follow, over a period of days to months, droplet maturation of the protein fused in sarcoma (FUS). Our study reveals that the surface of the droplets plays a critical role in this process, while RNA binding prevents it. The maturation kinetics are faster in an agarose-stabilized biphasic sample compared with a monophasic condensed sample, owing to the larger surface-to-volume ratio. In addition, Raman spectroscopy reports structural differences upon maturation between the inside and the surface of droplets, which is comprised of β-sheet content, as revealed by solid-state NMR. In agreement with these observations, a solid crust-like shell is observed at the surface using microaspiration. Ultimately, matured droplets were converted into fibrils involving the prion-like domain as well as the first RGG motif.
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Affiliation(s)
- Leonidas Emmanouilidis
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
- Bringing Materials to Life Initiative, ETH Zurich, Zurich, Switzerland.
| | - Ettore Bartalucci
- Max Planck Institute for Chemical Energy Conversion, Mülheim/Ruhr, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen, Germany
| | - Yelena Kan
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Mahdiye Ijavi
- Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Maria Escura Pérez
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | | | | | - Johannes Zehnder
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Sapun H Parekh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Thomas C T Michaels
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
- Bringing Materials to Life Initiative, ETH Zurich, Zurich, Switzerland
| | - Thomas Wiegand
- Max Planck Institute for Chemical Energy Conversion, Mülheim/Ruhr, Germany.
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen, Germany.
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland.
| | - Frédéric H-T Allain
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
- Bringing Materials to Life Initiative, ETH Zurich, Zurich, Switzerland.
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Demongin C, Tranier S, Joshi V, Ceschi L, Desforges B, Pastré D, Hamon L. RNA and the RNA-binding protein FUS act in concert to prevent TDP-43 spatial segregation. J Biol Chem 2024; 300:105716. [PMID: 38311174 PMCID: PMC10912363 DOI: 10.1016/j.jbc.2024.105716] [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: 09/12/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 02/10/2024] Open
Abstract
FUS and TDP-43 are two self-adhesive aggregation-prone mRNA-binding proteins whose pathological mutations have been linked to neurodegeneration. While TDP-43 and FUS form reversible mRNA-rich compartments in the nucleus, pathological mutations promote their respective cytoplasmic aggregation in neurons with no apparent link between the two proteins except their intertwined function in mRNA processing. By combining analyses in cellular context and at high resolution in vitro, we unraveled that TDP-43 is specifically recruited in FUS assemblies to form TDP-43-rich subcompartments but without reciprocity. The presence of mRNA provides an additional scaffold to promote the mixing between TDP-43 and FUS. Accordingly, we also found that the pathological truncated form of TDP-43, TDP-25, which has an impaired RNA-binding ability, no longer mixes with FUS. Together, these results suggest that the binding of FUS along nascent mRNAs enables TDP-43, which is highly aggregation-prone, to mix with FUS phase to form mRNA-rich subcompartments. A functional link between FUS and TDP-43 may explain their common implication in amyotrophic lateral sclerosis.
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Affiliation(s)
- Clément Demongin
- SABNP, Univ Evry, INSERM, U1204, Université Paris-Saclay, Evry, France
| | - Samuel Tranier
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Vandana Joshi
- SABNP, Univ Evry, INSERM, U1204, Université Paris-Saclay, Evry, France
| | - Léa Ceschi
- SABNP, Univ Evry, INSERM, U1204, Université Paris-Saclay, Evry, France
| | | | - David Pastré
- SABNP, Univ Evry, INSERM, U1204, Université Paris-Saclay, Evry, France
| | - Loic Hamon
- SABNP, Univ Evry, INSERM, U1204, Université Paris-Saclay, Evry, France.
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3
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Lao Z, Tang Y, Dong X, Tan Y, Li X, Liu X, Li L, Guo C, Wei G. Elucidating the reversible and irreversible self-assembly mechanisms of low-complexity aromatic-rich kinked peptides and steric zipper peptides. NANOSCALE 2024; 16:4025-4038. [PMID: 38347806 DOI: 10.1039/d3nr05130g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Many RNA-binding proteins such as fused-in sarcoma (FUS) can self-assemble into reversible liquid droplets and fibrils through the self-association of their low-complexity (LC) domains. Recent experiments have revealed that SYG-rich segments in the FUS LC domains play critical roles in the reversible self-assembly behaviors of FUS. These FUS LC segments alone can self-assemble into reversible kinked fibrils, which are markedly different from the canonical irreversible steric zipper β-sheet fibrils. However, the molecular determinants underlying the reversible and irreversible self-assembly are poorly understood. Herein we conducted extensive all-atom and coarse-grained molecular dynamics simulations of four representative hexapeptides: two low-complexity aromatic-rich kinked peptides from the amyotrophic lateral sclerosis-related FUS protein, FUS37-42 (SYSGYS) and FUS54-59 (SYSSYG); and two steric zipper peptides from Alzheimer's-associated Aβ and Tau proteins, Aβ16-21 (KLVFFA) and Tau306-311 (VQIVYK). We dissected their reversible and irreversible self-assembly dynamics, predicted their phase separation behaviors, and elucidated the underpinning molecular interactions. Our simulations showed that alternating stickers (Tyr) and spacers (Gly and Ser) in FUS37-42 and FUS54-59 facilitate the formation of highly dynamic coil-rich oligomers and lead to reversible self-assembly, while consecutive hydrophobic residues of LVFF in Aβ16-21 and IVY in Tau306-311 act as hydrophobic patches, favoring the formation of stable β-sheet-rich oligomers and driving the irreversible self-assembly. Intriguingly, we found that FUS37-42 and FUS54-59 peptides, possessing the same amino acid composition and the same number of sticker and spacer residues, display differential self-assembly propensities. This finding suggests that the self-assembly behaviors of FUS peptides are fine-tuned by the site-specific patterning of spacer residues (Ser and Gly). This study provides significant mechanistic insights into reversible and irreversible peptide self-assembly, which would be helpful for understanding the molecular mechanisms underlying the formation of biological liquid condensates and pathological solid amyloid fibrils.
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Affiliation(s)
- Zenghui Lao
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
| | - Yiming Tang
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
| | - Xuewei Dong
- Center for Soft Condensed Matter Physics and Interdisciplinary Research & School of Physical Science and Technology, Soochow University, Suzhou 215006, Jiangsu, China
| | - Yuan Tan
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xianshi Liu
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
| | - Le Li
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
| | - Cong Guo
- Department of Physics and International Centre for Quantum and Molecular Structures, College of Sciences, Shanghai University, Shanghai, China.
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai, China.
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4
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Matienko LI, Mil EM, Albantova AA, Goloshchapov AN. The Role H-Bonding and Supramolecular Structures in Homogeneous and Enzymatic Catalysis. Int J Mol Sci 2023; 24:16874. [PMID: 38069195 PMCID: PMC10707003 DOI: 10.3390/ijms242316874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
The article analyzes the role of hydrogen bonds and supramolecular structures in enzyme catalysis and model systems. Hydrogen bonds play a crucial role in many enzymatic reactions. However, scientists have only recently attempted to harness the power of hydrogen bonds in homogeneous catalytic systems. One of the newest directions is associated with attempts to control the properties of catalysts by influencing the "second coordination sphere" of metal complexes. The role H-bonding, and the building of stable supramolecular nanostructures due to intermolecular H-bonds, based on catalytic active heteroligand iron (Fe) or nickel (Ni) complexes formed during hydrocarbon oxidations were assessed via the AFM (Atomic-force microscopy) method, which was proposed and applied by authors of this manuscript. Th is article also discusses the roles of hydrogen bonds and supramolecular structures in oxidation reactions catalyzed by heteroligand Ni and Fe complexes, which are not only effective homogeneous catalysts but also structural and functional models of Oxygenases.
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Affiliation(s)
- Ludmila I. Matienko
- N.M. Emanuel Institution of Biochemical Physics Russian Academy of Science, 4 Kosygin Str., 119334 Moscow, Russia; (E.M.M.); (A.A.A.); (A.N.G.)
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Li D, Ma Y, Xia W, Tao Y, Zhang Y, Zhang H, Li D, Dai B, Liu C. Creating an Amyloid 'Kaleidoscope' Using Short Iodinated Peptides. Angew Chem Int Ed Engl 2023; 62:e202310737. [PMID: 37650358 DOI: 10.1002/anie.202310737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/01/2023]
Abstract
Amyloid fibrils formed by peptides with different sequences exhibit diversified morphologies, material properties and activities, making them valuable for developing functional bionanomaterials. However, the molecular understanding underlying the structural diversity of peptide fibrillar assembly at atomic level is still lacking. In this study, by using cryogenic electron microscopy, we first revealed the structural basis underlying the highly reversible assembly of 1 GFGGNDNFG9 (referred to as hnRAC1) peptide fibril. Furthermore, by installing iodine at different sites of hnRAC1, we generated a collection of peptide fibrils with distinct thermostability. By determining the atomic structures of the iodinated fibrils, we discovered that iodination at different sites of the peptide facilitates the formation of diverse halogen bonds and triggers the assembly of entirely different structures of iodinated fibrils. Finally, based on this structural knowledge, we designed an iodinated peptide that assembles into new atomic structures of fibrils, exhibiting superior thermostability, that aligned with our design. Our work provides an in-depth understanding of the atomic-level processes underlying the formation of diverse peptide fibril structures, and paves the way for creating an amyloid "kaleidoscope" by employing various modifications and peptide sequences to fine-tune the atomic structure and properties of fibrillar nanostructures.
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Affiliation(s)
- Danni Li
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yeyang Ma
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Wencheng Xia
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Youqi Tao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Yiling Zhang
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hong Zhang
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, 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
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bin Dai
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
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Choi HJ, Lee JY, Kim K. Glutathionylation on RNA-binding proteins: a regulator of liquid‒liquid phase separation in the pathogenesis of amyotrophic lateral sclerosis. Exp Mol Med 2023; 55:735-744. [PMID: 37009800 PMCID: PMC10167235 DOI: 10.1038/s12276-023-00978-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 04/04/2023] Open
Abstract
RNA-binding proteins (RBPs) containing low-sequence complexity domains mediate the formation of cellular condensates and membrane-less organelles with biological functions via liquid‒liquid phase separation (LLPS). However, the abnormal phase transition of these proteins induces the formation of insoluble aggregates. Aggregates are pathological hallmarks of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS). The molecular mechanisms underlying aggregate formation by ALS-associated RPBs remain largely unknown. This review highlights emerging studies on various posttranslational modifications (PTMs) related to protein aggregation. We begin with the introduction of several ALS-associated RBPs that form aggregates induced by phase separation. In addition, we highlight our recent discovery of a new PTM involved in the phase transition during the pathogenesis of fused-in-sarcoma (FUS)-associated ALS. We suggest a molecular mechanism through which LLPS mediates glutathionylation in FUS-linked ALS. This review aims to provide a detailed overview of the key molecular mechanisms of LLPS-mediated aggregate formation by PTMs, which will help further the understanding of the pathogenesis and development of ALS therapeutics.
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Affiliation(s)
- Hyun-Jun Choi
- Soonchunhyang Institute of Medi-bio Science, Soonchunhyang University, Cheonan, 31151, Korea
- Department of Integrated Biomedical Sciences, Soonchunhyang University, Cheonan, 31151, Korea
| | - Ji Young Lee
- Department of Medical Biotechnology, Soonchunhyang University, Asan, 31538, Korea
- Department of Medical Science, Soonchunhyang University, Asan, 31538, Korea
| | - Kiyoung Kim
- Department of Medical Science, Soonchunhyang University, Asan, 31538, Korea.
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Liu J, Wu XL, Zeng YT, Hu ZH, Lu JX. Solid-state NMR studies of amyloids. Structure 2023; 31:230-243. [PMID: 36750098 DOI: 10.1016/j.str.2023.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/10/2022] [Accepted: 01/09/2023] [Indexed: 02/08/2023]
Abstract
Amyloids have special structural properties and are involved in many aspects of biological function. In particular, amyloids are the cause or hallmarks of a group of notorious and incurable neurodegenerative diseases. The extraordinary high molecular weight and aggregation states of amyloids have posed a challenge for researchers studying them. Solid-state NMR (SSNMR) has been extensively applied to study the structures and dynamics of amyloids for the past 20 or more years and brought us tremendous progress in understanding their structure and related diseases. These studies, at the same time, helped to push SSNMR technical developments in sensitivity and resolution. In this review, some interesting research studies and important technical developments are highlighted to give the reader an overview of the current state of this field.
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Affiliation(s)
- Jing Liu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xia-Lian Wu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yu-Teng Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhi-Heng Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jun-Xia Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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Nishiyama Y, Hou G, Agarwal V, Su Y, Ramamoorthy A. Ultrafast Magic Angle Spinning Solid-State NMR Spectroscopy: Advances in Methodology and Applications. Chem Rev 2023; 123:918-988. [PMID: 36542732 PMCID: PMC10319395 DOI: 10.1021/acs.chemrev.2c00197] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Solid-state NMR spectroscopy is one of the most commonly used techniques to study the atomic-resolution structure and dynamics of various chemical, biological, material, and pharmaceutical systems spanning multiple forms, including crystalline, liquid crystalline, fibrous, and amorphous states. Despite the unique advantages of solid-state NMR spectroscopy, its poor spectral resolution and sensitivity have severely limited the scope of this technique. Fortunately, the recent developments in probe technology that mechanically rotate the sample fast (100 kHz and above) to obtain "solution-like" NMR spectra of solids with higher resolution and sensitivity have opened numerous avenues for the development of novel NMR techniques and their applications to study a plethora of solids including globular and membrane-associated proteins, self-assembled protein aggregates such as amyloid fibers, RNA, viral assemblies, polymorphic pharmaceuticals, metal-organic framework, bone materials, and inorganic materials. While the ultrafast-MAS continues to be developed, the minute sample quantity and radio frequency requirements, shorter recycle delays enabling fast data acquisition, the feasibility of employing proton detection, enhancement in proton spectral resolution and polarization transfer efficiency, and high sensitivity per unit sample are some of the remarkable benefits of the ultrafast-MAS technology as demonstrated by the reported studies in the literature. Although the very low sample volume and very high RF power could be limitations for some of the systems, the advantages have spurred solid-state NMR investigation into increasingly complex biological and material systems. As ultrafast-MAS NMR techniques are increasingly used in multidisciplinary research areas, further development of instrumentation, probes, and advanced methods are pursued in parallel to overcome the limitations and challenges for widespread applications. This review article is focused on providing timely comprehensive coverage of the major developments on instrumentation, theory, techniques, applications, limitations, and future scope of ultrafast-MAS technology.
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Affiliation(s)
- Yusuke Nishiyama
- JEOL Ltd., Akishima, Tokyo196-8558, Japan
- RIKEN-JEOL Collaboration Center, Yokohama, Kanagawa230-0045, Japan
| | - Guangjin Hou
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian116023, China
| | - Vipin Agarwal
- Tata Institute of Fundamental Research, Sy. No. 36/P, Gopanpally, Hyderabad500 046, India
| | - Yongchao Su
- Analytical Research and Development, Merck & Co., Inc., Rahway, New Jersey07065, United States
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, Michigan Neuroscience Institute, University of Michigan, Ann Arbor, Michigan41809-1055, United States
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Wittmer Y, Jami KM, Stowell RK, Le T, Hung I, Murray DT. Liquid Droplet Aging and Seeded Fibril Formation of the Cytotoxic Granule Associated RNA Binding Protein TIA1 Low Complexity Domain. J Am Chem Soc 2023; 145:1580-1592. [PMID: 36638831 PMCID: PMC9881004 DOI: 10.1021/jacs.2c08596] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Protein domains biased toward a few amino acid types are vital for the formation of biomolecular condensates in living cells. These membraneless compartments are formed by molecules exhibiting a range of molecular motions and structural order. Missense mutations increase condensate persistence lifetimes or structural order, properties that are thought to underlie pathological protein aggregation. In the context of stress granules associated with neurodegenerative diseases, this process involves the rigidification of protein liquid droplets into β-strand rich protein fibrils. Here, we characterize the molecular mechanism underlying the rigidification of liquid droplets for the low complexity domain of the Cytotoxic granule associated RNA binding protein TIA1 (TIA1) stress granule protein and the influence of a disease mutation linked to neurodegenerative diseases. A seeding procedure and solid state nuclear magnetic resonance measurements show that the low complexity domain converges on a β-strand rich fibril conformation composed of 21% of the sequence. Additional solid state nuclear magnetic resonance measurements and difference spectroscopy show that aged liquid droplets of wild type and a proline-to-leucine mutant low complexity domain are composed of fibril assemblies that are conformationally heterogeneous and structurally distinct from the seeded fibril preparation. Regarding low complexity domains, our data support the functional template-driven formation of conformationally homogeneous structures, that rigidification of liquid droplets into conformationally heterogenous structures promotes pathological interactions, and that the effect of disease mutations is more nuanced than increasing thermodynamic stability or increasing β-strand structure content.
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Affiliation(s)
- Yuuki Wittmer
- Department
of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Khaled M. Jami
- Department
of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Rachelle K. Stowell
- Department
of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Truc Le
- Department
of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Ivan Hung
- National
High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Dylan T. Murray
- Department
of Chemistry, University of California Davis, Davis, California 95616, United States,
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Different Intermolecular Interactions Drive Nonpathogenic Liquid-Liquid Phase Separation and Potentially Pathogenic Fibril Formation by TDP-43. Int J Mol Sci 2022; 23:ijms232315227. [PMID: 36499553 PMCID: PMC9741235 DOI: 10.3390/ijms232315227] [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: 09/26/2022] [Revised: 11/03/2022] [Accepted: 11/18/2022] [Indexed: 12/07/2022] Open
Abstract
The liquid-liquid phase separation (LLPS) of proteins has been found ubiquitously in eukaryotic cells, and is critical in the control of many biological processes by forming a temporary condensed phase with different bimolecular components. TDP-43 is recruited to stress granules in cells and is the main component of TDP-43 granules and proteinaceous amyloid inclusions in patients with amyotrophic lateral sclerosis (ALS). TDP-43 low complexity domain (LCD) is able to de-mix in solution, forming the protein condensed droplets, and amyloid aggregates would form from the droplets after incubation. The molecular interactions regulating TDP-43 LCD LLPS were investigated at the protein fusion equilibrium stage, when the droplets stopped growing after incubation. We found the molecules in the droplet were still liquid-like, but with enhanced intermolecular helix-helix interactions. The protein would only start to aggregate after a lag time and aggregate slower than at the condition when the protein does not phase separately into the droplets, or the molecules have a reduced intermolecular helix-helix interaction. In the protein condensed droplets, a structural transition intermediate toward protein aggregation was discovered involving a decrease in the intermolecular helix-helix interaction and a reduction in the helicity. Our results therefore indicate that different intermolecular interactions drive LLPS and fibril formation. The discovery that TDP-43 LCD aggregation was faster through the pathway without the first protein phase separation supports that LLPS and the intermolecular helical interaction could help maintain the stability of TDP-43 LCD.
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11
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Structure-dependent recruitment and diffusion of guest proteins in liquid droplets of FUS. Sci Rep 2022; 12:7101. [PMID: 35501371 PMCID: PMC9061845 DOI: 10.1038/s41598-022-11177-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/19/2022] [Indexed: 12/26/2022] Open
Abstract
Liquid droplets of a host protein, formed by liquid–liquid phase separation, recruit guest proteins and provide functional fields. Recruitment into p53 droplets is similar between disordered and folded guest proteins, whereas the diffusion of guest proteins inside droplets depends on their structural types. In this study, to elucidate how the recruitment and diffusion properties of guest proteins are affected by a host protein, we characterized the properties of guest proteins in fused in sarcoma (FUS) droplets using single-molecule fluorescence microscopy in comparison with p53 droplets. Unlike p53 droplets, disordered guest proteins were recruited into FUS droplets more efficiently than folded guest proteins, suggesting physical exclusion of the folded proteins from the small voids of the droplet. The recruitment did not appear to depend on the physical parameters (electrostatic or cation–π) of guests, implying that molecular size exclusion limits intermolecular interaction-assisted uptake. The diffusion of disordered guest proteins was comparable to that of the host FUS, whereas that of folded proteins varied widely, similar to the results for host p53. The scaling exponent of diffusion highlights the molecular sieving of large folded proteins in droplets. Finally, we proposed a molecular recruitment and diffusion model for guest proteins in FUS droplets.
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Abstract
In the last two decades, solid-state nuclear magnetic resonance (ssNMR) spectroscopy has transformed from a spectroscopic technique investigating small molecules and industrial polymers to a potent tool decrypting structure and underlying dynamics of complex biological systems, such as membrane proteins, fibrils, and assemblies, in near-physiological environments and temperatures. This transformation can be ascribed to improvements in hardware design, sample preparation, pulsed methods, isotope labeling strategies, resolution, and sensitivity. The fundamental engagement between nuclear spins and radio-frequency pulses in the presence of a strong static magnetic field is identical between solution and ssNMR, but the experimental procedures vastly differ because of the absence of molecular tumbling in solids. This review discusses routinely employed state-of-the-art static and MAS pulsed NMR methods relevant for biological samples with rotational correlation times exceeding 100's of nanoseconds. Recent developments in signal filtering approaches, proton methodologies, and multiple acquisition techniques to boost sensitivity and speed up data acquisition at fast MAS are also discussed. Several examples of protein structures (globular, membrane, fibrils, and assemblies) solved with ssNMR spectroscopy have been considered. We also discuss integrated approaches to structurally characterize challenging biological systems and some newly emanating subdisciplines in ssNMR spectroscopy.
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Affiliation(s)
- Sahil Ahlawat
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Nils-Alexander Lakomek
- University of Düsseldorf, Institute for Physical Biology, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Vipin Agarwal
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
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13
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Tagad A, Singh RK, Patwari GN. Binary Matrix Method to Enumerate, Hierarchically Order, and Structurally Classify Peptide Aggregation. J Chem Inf Model 2022; 62:1585-1594. [PMID: 35232014 DOI: 10.1021/acs.jcim.2c00069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein aggregation is a common and complex phenomenon in biological processes, yet a robust analysis of this aggregation process remains elusive. The commonly used methods such as center-of-mass to center-of-mass (COM-COM) distance, the radius of gyration (Rg), hydrogen bonding (HB), and solvent accessible surface area do not quantify the aggregation accurately. Herein, a new and robust method that uses an aggregation matrix (AM) approach to investigate peptide aggregation in a MD simulation trajectory is presented. An nxn two-dimensional AM is created by using the interpeptide Cα-Cα cutoff distances, which are binarily encoded (0 or 1). These aggregation matrices are analyzed to enumerate, hierarchically order, and structurally classify the aggregates. Comparison of the present AM method suggests that it is superior to the HB method since it can incorporate nonspecific interactions and the Rg and COM-COM methods since the cutoff distance is independent of the length of the peptide. More importantly, the present method can structurally classify the peptide aggregates, which the conventional Rg, COM-COM, and HB methods fail to do. The unique selling point of this method is its ability to structurally classify peptide aggregates using two-dimensional matrices.
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Affiliation(s)
- Amol Tagad
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Reman Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - G Naresh Patwari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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14
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Murray KA, Evans D, Hughes MP, Sawaya MR, Hu CJ, Houk KN, Eisenberg D. Extended β-Strands Contribute to Reversible Amyloid Formation. ACS NANO 2022; 16:2154-2163. [PMID: 35132852 DOI: 10.1021/acsnano.1c08043] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The assembly of proteins into fibrillar amyloid structures was once considered to be pathologic and essentially irreversible. Recent studies reveal amyloid-like structures that form reversibly, derived from protein low-complexity domains which function in cellular metabolism. Here, by comparing atomic-level structures of reversible and irreversible amyloid fibrils, we find that the β-sheets of reversible fibrils are enriched in flattened (as opposed to pleated) β-sheets formed by stacking of extended β-strands. Quantum mechanical calculations show that glycine residues favor extended β-strands which may be stabilized by intraresidue interactions between the amide proton and the carbonyl oxygen, known as C5 hydrogen-bonds. Larger residue side chains favor shorter strands and pleated sheets. These findings highlight a structural element that may regulate reversible amyloid assembly.
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15
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Sun Y, Zhang S, Hu J, Tao Y, Xia W, Gu J, Li Y, Cao Q, Li D, Liu C. Molecular structure of an amyloid fibril formed by FUS low-complexity domain. iScience 2022; 25:103701. [PMID: 35036880 PMCID: PMC8749265 DOI: 10.1016/j.isci.2021.103701] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 12/22/2021] [Indexed: 01/25/2023] Open
Abstract
FUS is a multifunctional nuclear protein which undergoes liquid–liquid phase separation in response to stress and DNA damage. Dysregulation of FUS dynamic phase separation leads to formation of pathological fibril closely associated with neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal dementia. In this study, we determined the cryo-EM structure of a cytotoxic fibril formed by the low-complexity (LC) domain of FUS at 2.9 Å resolution. The fibril structure exhibits a new and extensive serpentine fold consisting of three motifs incorporating together via a Tyr triad. FUS LC employs 91 residues to form an enlarged and stable fibril core via hydrophilic interaction and hydrogen bonds, which is distinct from most of previously determined fibrils commonly stabilized by hydrophobic interaction. Our work reveals the structural basis underlying formation of a cytotoxic and thermostable fibril of FUS LC and sheds light on understanding the liquid-to-solid phase transition of FUS in disease. Cryo-EM structure of an amyloid fibril formed by FUS low-complexity (LC) domain FUS LC forms a novel enlarged and thermostable fibril core (FC) involving 91 residues Hydrophilic interaction and hydrogen bonds are essential in FC formation of FUS LC
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Affiliation(s)
- Yunpeng Sun
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Shenqing Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China.,Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiaojiao Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Youqi Tao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China.,Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wencheng Xia
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jinge Gu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yichen Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China.,Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qin Cao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, 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.,Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China.,Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
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16
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Kumar A, Chakraborty D, Mugnai ML, Straub JE, Thirumalai D. Sequence Determines the Switch in the Fibril Forming Regions in the Low-Complexity FUS Protein and Its Variants. J Phys Chem Lett 2021; 12:9026-9032. [PMID: 34516126 PMCID: PMC8826754 DOI: 10.1021/acs.jpclett.1c02310] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Residues spanning distinct regions of the low-complexity domain of the RNA-binding protein, Fused in Sarcoma (FUS-LC), form fibril structures with different core morphologies. Solid-state NMR experiments show that the 214-residue FUS-LC forms a fibril with an S-bend (core-1, residues 39-95), while the rest of the protein is disordered. In contrast, the fibrils of the C-terminal variant (FUS-LC-C; residues 111-214) have a U-bend topology (core-2, residues 112-150). Absence of the U-bend in FUS-LC implies that the two fibril cores do not coexist. Computer simulations show that these perplexing findings could be understood in terms of the population of sparsely populated fibril-like excited states in the monomer. The propensity to form core-1 is higher compared to core-2. We predict that core-2 forms only in truncated variants that do not contain the core-1 sequence. At the monomer level, sequence-dependent enthalpic effects determine the relative stabilities of the core-1 and core-2 topologies.
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Affiliation(s)
- Abhinaw Kumar
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Debayan Chakraborty
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mauro Lorenzo Mugnai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - John E Straub
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - D Thirumalai
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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17
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Chien HM, Lee CC, Huang JJT. The Different Faces of the TDP-43 Low-Complexity Domain: The Formation of Liquid Droplets and Amyloid Fibrils. Int J Mol Sci 2021; 22:ijms22158213. [PMID: 34360978 PMCID: PMC8348237 DOI: 10.3390/ijms22158213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
Transactive response DNA-binding protein 43 (TDP-43) is a nucleic acid-binding protein that is involved in transcription and translation regulation, non-coding RNA processing, and stress granule assembly. Aside from its multiple functions, it is also known as the signature protein in the hallmark inclusions of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) patients. TDP-43 is built of four domains, but its low-complexity domain (LCD) has become an intense research focus that brings to light its possible role in TDP-43 functions and involvement in the pathogenesis of these neurodegenerative diseases. Recent endeavors have further uncovered the distinct biophysical properties of TDP-43 under various circumstances. In this review, we summarize the multiple structural and biochemical properties of LCD in either promoting the liquid droplets or inducing fibrillar aggregates. We also revisit the roles of the LCD in paraspeckles, stress granules, and cytoplasmic inclusions to date.
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Affiliation(s)
- Hung-Ming Chien
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
- Department of Chemistry, National Taiwan University, Taipei City 115, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei City 115, Taiwan
| | - Chi-Chang Lee
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
| | - Joseph Jen-Tse Huang
- Institute of Chemistry, Academia Sinica, Nangang, Taipei City 115, Taiwan; (H.-M.C.); (C.-C.L.)
- Department of Applied Chemistry, National Chiayi University, Chiayi City 600, Taiwan
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei City 115, Taiwan
- Correspondence: ; Tel.: +886-2-5572-8652
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18
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Wang WJ, Mu X, Tan CP, Wang YJ, Zhang Y, Li G, Mao ZW. Induction and Monitoring of DNA Phase Separation in Living Cells by a Light-Switching Ruthenium Complex. J Am Chem Soc 2021; 143:11370-11381. [PMID: 34291952 DOI: 10.1021/jacs.1c01424] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Phase separation of DNA is involved in chromatin packing for the regulation of gene transcription. Visualization and manipulation of DNA phase separation in living cells present great challenges. Herein, we present a Ru(II) complex (Ru1) with high DNA binding affinity and DNA "light-switch" behavior that can induce and monitor DNA phase separation both in vitro and in living cells. Molecular dynamics simulations indicate that the two phen-PPh3 ligands with positively charged lipophilic triphenylphosphine substituents and flexible long alkyl chains in Ru1 play essential roles in the formation of multivalent binding forces between DNA molecules to induce DNA phase separation. Importantly, the unique environmental sensitive emission property of Ru1 enables direct visualization of the dynamic process of DNA phase separation in living cells by two-photon phosphorescent lifetime imaging. Moreover, Ru1 can change the gene expression pattern by modulating chromatin accessibility as demonstrated by integrating RNA-sequencing and transposase-accessible chromatin with high-throughput sequencing. In all, we present here the first small-molecule-based tracer and modulator of DNA phase separation in living cells and elucidate its impact on the chromatin state and transcriptome.
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Affiliation(s)
- Wen-Jin Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, State Key Laboratory of Oncology in South China, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Xia Mu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Cai-Ping Tan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, State Key Laboratory of Oncology in South China, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Yu-Jian Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, State Key Laboratory of Oncology in South China, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Yuebin Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Guohui Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Zong-Wan Mao
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, State Key Laboratory of Oncology in South China, Sun Yat-Sen University, Guangzhou 510275, P. R. China
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19
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Characterization of design grammar of peptides for regulating liquid droplets and aggregates of FUS. Sci Rep 2021; 11:6643. [PMID: 33758287 PMCID: PMC7988016 DOI: 10.1038/s41598-021-86098-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
Liquid droplets of aggregation-prone proteins, which become hydrogels or form amyloid fibrils, are a potential target for drug discovery. In this study, we proposed an experiment-guided protocol for characterizing the design grammar of peptides that can regulate droplet formation and aggregation. The protocol essentially involves investigation of 19 amino acid additives and polymerization of the identified amino acids. As a proof of concept, we applied this protocol to fused in sarcoma (FUS). First, we evaluated 19 amino acid additives for an FUS solution and identified Arg and Tyr as suppressors of droplet formation. Molecular dynamics simulations suggested that the Arg additive interacts with specific residues of FUS, thereby inhibiting the cation-π and electrostatic interactions between the FUS molecules. Second, we observed that Arg polymers promote FUS droplet formation, unlike Arg monomers, by bridging the FUS molecules. Third, we found that the Arg additive suppressed solid aggregate formation of FUS, while Arg polymer enhanced it. Finally, we observed that amyloid-forming peptides induced the conversion of FUS droplets to solid aggregates of FUS. The developed protocol could be used for the primary design of peptides controlling liquid droplets and aggregates of proteins.
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20
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Real-time observation of structure and dynamics during the liquid-to-solid transition of FUS LC. Biophys J 2021; 120:1276-1287. [PMID: 33607084 DOI: 10.1016/j.bpj.2021.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/21/2021] [Accepted: 02/08/2021] [Indexed: 12/11/2022] Open
Abstract
A subset of the proteins found in pathological protein fibrils also exhibit tendencies for liquid-liquid phase separation (LLPS) both in vitro and in cells. The mechanisms underlying the connection between these phase transitions have been challenging to study due to the heterogeneous and dynamic nature of the states formed during the maturation of LLPS protein droplets into gels and solid aggregates. Here, we interrogate the liquid-to-solid transition of the low-complexity domain of the RNA-binding protein FUS (FUS LC), which has been shown to adopt LLPS, gel-like, and amyloid states. We employ magic-angle-spinning NMR spectroscopy, which has allowed us to follow these transitions in real time and with residue-specific resolution. We observe the development of β-sheet structure through the maturation process and show that the final state of FUS LC fibrils produced after LLPS is distinct from that grown from fibrillar seeds. We also apply our methodology to FUS LC G156E, a clinically relevant FUS mutant that exhibits accelerated fibrillization rates. We observe significant changes in dynamics during the transformation of the FUS LC G156E construct and begin to unravel the sequence specific contributions to this phenomenon with computational studies of the phase-separated state of FUS LC and FUS LC G156E.
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21
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Alderson TR, Kay LE. NMR spectroscopy captures the essential role of dynamics in regulating biomolecular function. Cell 2021; 184:577-595. [PMID: 33545034 DOI: 10.1016/j.cell.2020.12.034] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/09/2020] [Accepted: 12/21/2020] [Indexed: 01/02/2023]
Abstract
Biomolecules are in constant motion. To understand how they function, and why malfunctions can cause disease, it is necessary to describe their three-dimensional structures in terms of dynamic conformational ensembles. Here, we demonstrate how nuclear magnetic resonance (NMR) spectroscopy provides an essential, dynamic view of structural biology that captures biomolecular motions at atomic resolution. We focus on examples that emphasize the diversity of biomolecules and biochemical applications that are amenable to NMR, such as elucidating functional dynamics in large molecular machines, characterizing transient conformations implicated in the onset of disease, and obtaining atomic-level descriptions of intrinsically disordered regions that make weak interactions involved in liquid-liquid phase separation. Finally, we discuss the pivotal role that NMR has played in driving forward our understanding of the biomolecular dynamics-function paradigm.
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Affiliation(s)
- T Reid Alderson
- Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Chemistry, The University of Toronto, Toronto, ON M5S A18, Canada.
| | - Lewis E Kay
- Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Chemistry, The University of Toronto, Toronto, ON M5S A18, Canada; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
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22
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Reif B, Ashbrook SE, Emsley L, Hong M. Solid-state NMR spectroscopy. NATURE REVIEWS. METHODS PRIMERS 2021; 1:2. [PMID: 34368784 PMCID: PMC8341432 DOI: 10.1038/s43586-020-00002-1] [Citation(s) in RCA: 182] [Impact Index Per Article: 60.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/29/2020] [Indexed: 12/18/2022]
Abstract
Solid-state nuclear magnetic resonance (NMR) spectroscopy is an atomic-level method used to determine the chemical structure, three-dimensional structure, and dynamics of solids and semi-solids. This Primer summarizes the basic principles of NMR as applied to the wide range of solid systems. The fundamental nuclear spin interactions and the effects of magnetic fields and radiofrequency pulses on nuclear spins are the same as in liquid-state NMR. However, because of the anisotropy of the interactions in the solid state, the majority of high-resolution solid-state NMR spectra is measured under magic-angle spinning (MAS), which has profound effects on the types of radiofrequency pulse sequences required to extract structural and dynamical information. We describe the most common MAS NMR experiments and data analysis approaches for investigating biological macromolecules, organic materials, and inorganic solids. Continuing development of sensitivity-enhancement approaches, including 1H-detected fast MAS experiments, dynamic nuclear polarization, and experiments tailored to ultrahigh magnetic fields, is described. We highlight recent applications of solid-state NMR to biological and materials chemistry. The Primer ends with a discussion of current limitations of NMR to study solids, and points to future avenues of development to further enhance the capabilities of this sophisticated spectroscopy for new applications.
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Affiliation(s)
- Bernd Reif
- Technische Universität München, Department Chemie, Lichtenbergstr. 4, D-85747 Garching, Germany
| | - Sharon E. Ashbrook
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Lyndon Emsley
- École Polytechnique Fédérale de Lausanne (EPFL), Institut des sciences et ingénierie chimiques, CH-1015 Lausanne, Switzerland
| | - Mei Hong
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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23
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Lee M, Ghosh U, Thurber KR, Kato M, Tycko R. Molecular structure and interactions within amyloid-like fibrils formed by a low-complexity protein sequence from FUS. Nat Commun 2020; 11:5735. [PMID: 33184287 PMCID: PMC7665218 DOI: 10.1038/s41467-020-19512-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
Protein domains without the usual distribution of amino acids, called low complexity (LC) domains, can be prone to self-assembly into amyloid-like fibrils. Self-assembly of LC domains that are nearly devoid of hydrophobic residues, such as the 214-residue LC domain of the RNA-binding protein FUS, is particularly intriguing from the biophysical perspective and is biomedically relevant due to its occurrence within neurons in amyotrophic lateral sclerosis, frontotemporal dementia, and other neurodegenerative diseases. We report a high-resolution molecular structural model for fibrils formed by the C-terminal half of the FUS LC domain (FUS-LC-C, residues 111-214), based on a density map with 2.62 Å resolution from cryo-electron microscopy (cryo-EM). In the FUS-LC-C fibril core, residues 112-150 adopt U-shaped conformations and form two subunits with in-register, parallel cross-β structures, arranged with quasi-21 symmetry. All-atom molecular dynamics simulations indicate that the FUS-LC-C fibril core is stabilized by a plethora of hydrogen bonds involving sidechains of Gln, Asn, Ser, and Tyr residues, both along and transverse to the fibril growth direction, including diverse sidechain-to-backbone, sidechain-to-sidechain, and sidechain-to-water interactions. Nuclear magnetic resonance measurements additionally show that portions of disordered residues 151-214 remain highly dynamic in FUS-LC-C fibrils and that fibrils formed by the N-terminal half of the FUS LC domain (FUS-LC-N, residues 2-108) have the same core structure as fibrils formed by the full-length LC domain. These results contribute to our understanding of the molecular structural basis for amyloid formation by FUS and by LC domains in general.
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Affiliation(s)
- Myungwoon Lee
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520, USA
| | - Ujjayini Ghosh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520, USA
| | - Kent R Thurber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520, USA
| | - Masato Kato
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas, 75390-9152, USA
- Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, Chiba, 263-8555, Japan
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892-0520, USA.
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24
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Dregni AJ, Duan P, Hong M. Hydration and Dynamics of Full-Length Tau Amyloid Fibrils Investigated by Solid-State Nuclear Magnetic Resonance. Biochemistry 2020; 59:2237-2248. [PMID: 32453948 PMCID: PMC7720860 DOI: 10.1021/acs.biochem.0c00342] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The microtubule-associated protein tau aggregates into distinct neurofibrillary tangles in brains afflicted with multiple neurodegenerative diseases such as Alzheimer's disease and corticobasal degeneration (CBD). The mechanism of tau misfolding and aggregation is poorly understood. Determining the structure, dynamics, and water accessibility of tau filaments may provide insight into the pathway of tau misfolding. Here, we investigate the hydration and dynamics of the β-sheet core of heparin-fibrillized 0N4R tau using solid-state nuclear magnetic resonance spectroscopy. This β-sheet core consists of the second and third microtubule-binding repeats, R2 and R3, respectively, which form a hairpin. Water-edited two-dimensional (2D) 13C-13C and 15N-13C correlation spectra show that most residues in R2 and R3 domains have low water accessibility, indicating that this hairpin is surrounded by other proteinaceous segments. However, a small number of residues, especially S285 and S316, are well hydrated compared to other Ser and Thr residues, suggesting that there is a small water channel in the middle of the hairpin. To probe whether water accessibility correlates with protein dynamics, we measured the backbone N-H dipolar couplings of the β-sheet core. Interestingly, residues in the fourth microtubule-binding repeat, R4, show rigid-limit N-H dipolar couplings, even though this domain exhibits weaker intensities in the 2D 15N-13C correlation spectra. These results suggest that the R4 domain participates in cross-β hydrogen bonding in some of the subunits but exhibits dynamic disorder in other subunits. Taken together, these hydration and dynamics data indicate that the R2-R3 hairpin of 0N4R tau is shielded from water by other proteinaceous segments on the exterior but contains a small water pore in the interior. This structural topology has various similarities with the CBD tau fibril structure but also shows specific differences. The disorder of the R4 domain and the presence of a small water channel in the heparin-fibrillized 4R tau have implications for the structure of tau fibrils in diseased brains.
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Affiliation(s)
| | | | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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25
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Yoshizawa T, Nozawa RS, Jia TZ, Saio T, Mori E. Biological phase separation: cell biology meets biophysics. Biophys Rev 2020; 12:519-539. [PMID: 32189162 PMCID: PMC7242575 DOI: 10.1007/s12551-020-00680-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022] Open
Abstract
Progress in development of biophysical analytic approaches has recently crossed paths with macromolecule condensates in cells. These cell condensates, typically termed liquid-like droplets, are formed by liquid-liquid phase separation (LLPS). More and more cell biologists now recognize that many of the membrane-less organelles observed in cells are formed by LLPS caused by interactions between proteins and nucleic acids. However, the detailed biophysical processes within the cell that lead to these assemblies remain largely unexplored. In this review, we evaluate recent discoveries related to biological phase separation including stress granule formation, chromatin regulation, and processes in the origin and evolution of life. We also discuss the potential issues and technical advancements required to properly study biological phase separation.
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Affiliation(s)
- Takuya Yoshizawa
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Ryu-Suke Nozawa
- Division of Experimental Pathology, Cancer Institute of the Japanese Foundation for Cancer Research (JFCR), Tokyo, Japan
| | - Tony Z Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Blue Marble Space Institute of Science, Seattle, WA, USA
| | - Tomohide Saio
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Eiichiro Mori
- Department of Future Basic Medicine, Nara Medical University, Kashihara, Nara, Japan.
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