1
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Soliman AS, Umstead A, Lamp J, Vega IE. EFhd2 co-aggregates with monomeric and filamentous tau in vitro. Front Neurosci 2024; 18:1373410. [PMID: 38765673 PMCID: PMC11100465 DOI: 10.3389/fnins.2024.1373410] [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: 01/19/2024] [Accepted: 04/15/2024] [Indexed: 05/22/2024] Open
Abstract
Tauopathies are characterized by the abnormal buildup of tau protein, with early oligomeric forms associated with neurodegeneration and the later neurofibrillary tangles possibly conferring neuroprotection. The molecular mechanisms governing the formation of these tau species are unclear. Lately, there has been an increased focus on examining the interactions between tau and other proteins, along with their influence on the aggregation of tau. Our previous work revealed EFhd2's association with pathological tau in animal models and tauopathy brains. Herein, we examined the impact of EFhd2 on monomeric and filamentous tau in vitro. The results demonstrated that EFhd2 incubation with monomeric full length human tau (hTau40) formed amorphous aggregates, where both EFhd2 and hTau40 colocalized. Moreover, EFhd2 is entangled with arachidonic acid (ARA)-induced filamentous hTau40. Furthermore, EFhd2-induced aggregation with monomeric and filamentous hTau40 is EFhd2 concentration dependent. Using sandwich ELISA assays, we assessed the reactivity of TOC1 and Alz50-two conformation-specific tau antibodies-to EFhd2-hTau40 aggregates (in absence and presence of ARA). No TOC1 signal was detected in EFhd2 aggregates with monomeric hTau40 whereas EFhd2 aggregates with hTau in the presence of ARA showed a higher signal compared to hTau40 filaments. In contrast, EFhd2 aggregates with both monomeric and filamentous hTau40 reduced Alz50 reactivity. Taken together, our results illustrate for the first time that EFhd2, a tau-associated protein, interacts with monomeric and filamentous hTau40 to form large aggregates that are starkly different from tau oligomers and filaments. Given these findings and previous research, we hypothesize that EFhd2 may play a role in the formation of tau aggregates. Nevertheless, further in vivo studies are imperative to test this hypothesis.
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Affiliation(s)
- Ahlam S. Soliman
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Andrew Umstead
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
- Integrated Mass Spectrometry Unit, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Jared Lamp
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Irving E. Vega
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
- Neuroscience Program, Michigan State University, East Lansing, MI, United States
- Integrated Mass Spectrometry Unit, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States
- Michigan Alzheimer's Disease Research Center, University of Michigan, Ann Arbor, MI, United States
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2
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Hilditch AT, Romanyuk A, Hodgson LR, Mantell J, Neal CR, Verkade P, Obexer R, Serpell LC, McManus JJ, Woolfson DN. Maturation and Conformational Switching of a De Novo Designed Phase-Separating Polypeptide. J Am Chem Soc 2024; 146:10240-10245. [PMID: 38578222 PMCID: PMC11027135 DOI: 10.1021/jacs.4c00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/06/2024]
Abstract
Cellular compartments formed by biomolecular condensation are widespread features of cell biology. These organelle-like assemblies compartmentalize macromolecules dynamically within the crowded intracellular environment. However, the intermolecular interactions that produce condensed droplets may also create arrested states and potentially pathological assemblies such as fibers, aggregates, and gels through droplet maturation. Protein liquid-liquid phase separation is a metastable process, so maturation may be an intrinsic property of phase-separating proteins, where nucleation of different phases or states arises in supersaturated condensates. Here, we describe the formation of both phase-separated droplets and proteinaceous fibers driven by a de novo designed polypeptide. We characterize the formation of supramolecular fibers in vitro and in bacterial cells. We show that client proteins can be targeted to the fibers in cells using a droplet-forming construct. Finally, we explore the interplay between phase separation and fiber formation of the de novo polypeptide, showing that the droplets mature with a post-translational switch to largely β conformations, analogous to models of pathological phase separation.
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Affiliation(s)
- Alexander T. Hilditch
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- Max
Planck-Bristol Centre for Minimal Biology, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Andrey Romanyuk
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- Max
Planck-Bristol Centre for Minimal Biology, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Lorna R. Hodgson
- Wolfson
Bioimaging Facility, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K.
| | - Judith Mantell
- Wolfson
Bioimaging Facility, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K.
| | - Christopher R. Neal
- Wolfson
Bioimaging Facility, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K.
| | - Paul Verkade
- School
of Biochemistry, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K.
- Bristol
BioDesign Institute, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
| | - Richard Obexer
- Department
of Chemistry, Manchester Institute of Biotechnology, University of Manchester, Princess Street, Manchester M1 7DN, U.K.
| | - Louise C. Serpell
- School
of Life Sciences, University of Sussex, Falmer, Brighton, JMS 3B17, U.K.
| | - Jennifer J. McManus
- Bristol
BioDesign Institute, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- HH Wills
Physics Laboratory, School of Physics, University
of Bristol, Tyndall Avenue, Bristol BS8 1TL, U.K.
| | - Derek N. Woolfson
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- Max
Planck-Bristol Centre for Minimal Biology, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
- School
of Biochemistry, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, U.K.
- Bristol
BioDesign Institute, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K.
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3
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Fu Q, Zhang B, Chen X, Chu L. Liquid-liquid phase separation in Alzheimer's disease. J Mol Med (Berl) 2024; 102:167-181. [PMID: 38167731 DOI: 10.1007/s00109-023-02407-3] [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: 04/17/2023] [Revised: 11/26/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
The pathological aggregation and misfolding of tau and amyloid-β play a key role in Alzheimer's disease (AD). However, the underlying pathological mechanisms remain unclear. Emerging evidences indicate that liquid-liquid phase separation (LLPS) has great impacts on regulating human health and diseases, especially neurodegenerative diseases. A series of studies have revealed the significance of LLPS in AD. In this review, we summarize the latest progress of LLPS in AD, focusing on the impact of metal ions, small-molecule inhibitors, and proteinaceous partners on tau LLPS and aggregation, as well as toxic oligomerization, the role of LLPS on amyloid-β (Aβ) aggregation, and the cross-interactions between amyloidogenic proteins in AD. Eventually, the fundamental methods and techniques used in LLPS study are introduced. We expect to present readers a deeper understanding of the relationship between LLPS and AD.
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Affiliation(s)
- Qinggang Fu
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Bixiang Zhang
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Xiaoping Chen
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Liang Chu
- Hepatic Surgery Center and Hubei Key Laboratory of Hepato-Pancreatic-Biliary Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
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4
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Ramšak M, Ramirez DA, Hough LE, Shirts MR, Vidmar S, Eleršič Filipič K, Anderluh G, Jerala R. Programmable de novo designed coiled coil-mediated phase separation in mammalian cells. Nat Commun 2023; 14:7973. [PMID: 38042897 PMCID: PMC10693550 DOI: 10.1038/s41467-023-43742-w] [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: 06/29/2023] [Accepted: 11/17/2023] [Indexed: 12/04/2023] Open
Abstract
Membraneless liquid compartments based on phase-separating biopolymers have been observed in diverse cell types and attributed to weak multivalent interactions predominantly based on intrinsically disordered domains. The design of liquid-liquid phase separated (LLPS) condensates based on de novo designed tunable modules that interact in a well-understood, controllable manner could improve our understanding of this phenomenon and enable the introduction of new features. Here we report the construction of CC-LLPS in mammalian cells, based on designed coiled-coil (CC) dimer-forming modules, where the stability of CC pairs, their number, linkers, and sequential arrangement govern the transition between diffuse, liquid and immobile condensates and are corroborated by coarse-grained molecular simulations. Through modular design, we achieve multiple coexisting condensates, chemical regulation of LLPS, condensate fusion, formation from either one or two polypeptide components or LLPS regulation by a third polypeptide chain. These findings provide further insights into the principles underlying LLPS formation and a design platform for controlling biological processes.
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Affiliation(s)
- Maruša Ramšak
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
- Interdisciplinary doctoral study of biomedicine, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Dominique A Ramirez
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Loren E Hough
- Department of Physics and BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
| | - Michael R Shirts
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Sara Vidmar
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
- Interdisciplinary doctoral study of biomedicine, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Kristina Eleršič Filipič
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Roman Jerala
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.
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5
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Sołtys K, Tarczewska A, Bystranowska D. Modulation of biomolecular phase behavior by metal ions. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119567. [PMID: 37582439 DOI: 10.1016/j.bbamcr.2023.119567] [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: 04/03/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/17/2023]
Abstract
Liquid-liquid phase separation (LLPS) appears to be a newly appreciated aspect of the cellular organization of biomolecules that leads to the formation of membraneless organelles (MLOs). MLOs generate distinct microenvironments where particular biomolecules are highly concentrated compared to those in the surrounding environment. Their thermodynamically driven formation is reversible, and their liquid nature allows them to fuse with each other. Dysfunctional biomolecular condensation is associated with human diseases. Pathological states of MLOs may originate from the mutation of proteins or may be induced by other factors. In most aberrant MLOs, transient interactions are replaced by stronger and more rigid interactions, preventing their dissolution, and causing their uncontrolled growth and dysfunction. For these reasons, there is great interest in identifying factors that modulate LLPS. In this review, we discuss an enigmatic and mostly unexplored aspect of this process, namely, the regulatory effects of metal ions on the phase behavior of biomolecules.
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Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Aneta Tarczewska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Dominika Bystranowska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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6
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Emamyari S, Mirzaei M, Mohammadinejad S, Fazli D, Fazli H. Impact of flexibility on the aggregation of polymeric macromolecules. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:66. [PMID: 37522950 DOI: 10.1140/epje/s10189-023-00324-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/17/2023] [Indexed: 08/01/2023]
Abstract
Dependence of the dimerization probability and the aggregation behavior of polymeric macromolecules on their flexibility is studied using Langevin dynamics simulations. It is found that the dimerization probability is a non-monotonic function of the polymers persistence length. For a given value of inter-polymer attraction strength, semiflexible polymers have lower dimerization probability relative to flexible and rigid polymers of the same length. The threshold temperature of the formation of aggregates in a many-polymer system and its dependence on the polymers persistence length is also investigated. The simulation results of two- and many-polymer systems are in good agreement and show how the amount of flexibility affects the dimerization and the aggregation behaviors of polymeric macromolecules.
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Affiliation(s)
- Soheila Emamyari
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran
| | - Masoud Mirzaei
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran
| | - Sarah Mohammadinejad
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran
| | - Davood Fazli
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran
| | - Hossein Fazli
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran.
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Prof. Yousef Sobouti Blvd., Zanjan, 45137-66731, Iran.
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7
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Li P, Chen J, Wang X, Su Z, Gao M, Huang Y. Liquid - liquid phase separation of tau: Driving forces, regulation, and biological implications. Neurobiol Dis 2023; 183:106167. [PMID: 37230179 DOI: 10.1016/j.nbd.2023.106167] [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: 03/26/2023] [Revised: 05/16/2023] [Accepted: 05/21/2023] [Indexed: 05/27/2023] Open
Abstract
The past 15 years have witnessed an explosion in the studies of biomolecular condensates that are implicated in numerous biological processes and play vital roles in human health and diseases. Recent findings demonstrate that the microtubule-associated protein tau forms liquid condensates through liquid-liquid phase separation (LLPS) in in vitro experiments using purified recombinant proteins and cell-based experiments. Although in vivo studies are lacking, liquid condensates have emerged as an important assembly state of physiological and pathological tau and LLPS can regulate the function of microtubules, mediate stress granule formation, and accelerate tau amyloid aggregation. In this review, we summarize recent advances in tau LLPS, aiming to unveiling the delicate interactions driving tau LLPS. We further discuss the association of tau LLPS with physiology and disease in the context of the sophisticated regulation of tau LLPS. Deciphering the mechanisms underlying tau LLPS and the liquid-to-solid transition enables rational design of molecules that inhibit or delay the formation of tau solid species, thus providing novel targeted therapeutic strategies for tauopathies.
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Affiliation(s)
- Ping Li
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Jingxin Chen
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Xi Wang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Zhengding Su
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Meng Gao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China.
| | - Yongqi Huang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China.
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8
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Shil S, Tsuruta M, Kawauchi K, Miyoshi D. Biomolecular Liquid-Liquid Phase Separation for Biotechnology. BIOTECH 2023; 12:26. [PMID: 37092470 PMCID: PMC10123627 DOI: 10.3390/biotech12020026] [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: 03/09/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
The liquid-liquid phase separation (LLPS) of biomolecules induces condensed assemblies called liquid droplets or membrane-less organelles. In contrast to organelles with lipid membrane barriers, the liquid droplets induced by LLPS do not have distinct barriers (lipid bilayer). Biomolecular LLPS in cells has attracted considerable attention in broad research fields from cellular biology to soft matter physics. The physical and chemical properties of LLPS exert a variety of functions in living cells: activating and deactivating biomolecules involving enzymes; controlling the localization, condensation, and concentration of biomolecules; the filtration and purification of biomolecules; and sensing environmental factors for fast, adaptive, and reversible responses. The versatility of LLPS plays an essential role in various biological processes, such as controlling the central dogma and the onset mechanism of pathological diseases. Moreover, biomolecular LLPS could be critical for developing new biotechnologies such as the condensation, purification, and activation of a series of biomolecules. In this review article, we introduce some fundamental aspects and recent progress of biomolecular LLPS in living cells and test tubes. Then, we discuss applications of biomolecular LLPS toward biotechnologies.
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Affiliation(s)
| | | | | | - Daisuke Miyoshi
- Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, 7-1-20 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Hyogo, Japan
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9
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Ainani H, Bouchmaa N, Ben Mrid R, El Fatimy R. Liquid-liquid phase separation of protein tau: An emerging process in Alzheimer's disease pathogenesis. Neurobiol Dis 2023; 178:106011. [PMID: 36702317 DOI: 10.1016/j.nbd.2023.106011] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 01/04/2023] [Accepted: 01/21/2023] [Indexed: 01/24/2023] Open
Abstract
Metabolic reactions within cells occur in various isolated compartments with or without borders, the latter being known as membrane-less organelles (MLOs). The MLOs show liquid-like properties and are formed by a process known as liquid-liquid phase separation (LLPS). MLOs contribute to different molecules interactions such as protein-protein, protein-RNA, and RNA-RNA driven by various factors, such as multivalency of intrinsic disorders. MLOs are involved in several cell signaling pathways such as transcription, immune response, and cellular organization. However, disruption of these processes has been found in different pathologies. Recently, it has been demonstrated that protein aggregates, a characteristic of some neurodegenerative diseases, undergo similar phase separation. Tau protein is known as a major neurofibrillary tangles component in Alzheimer's disease (AD). This protein can undergo phase separation to form a MLO known as tau droplet in vitro and in vivo, and this process can be facilitated by several factors, including crowding agents, RNA, and phosphorylation. Tau droplet has been shown to mature into insoluble aggregates suggesting that this process may precede and induce neurodegeneration in AD. Here we review major factors involved in liquid droplet formation within a cell. Additionally, we highlight recent findings concerning tau aggregation following phase separation in AD, along with the potential therapeutic strategies that could be explored in this process against the progression of this pathology.
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Affiliation(s)
- Hassan Ainani
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Najat Bouchmaa
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Reda Ben Mrid
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Rachid El Fatimy
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco.
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10
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Vega IE, Umstead A. Liquid-Liquid Phase Separation to Study the Association of Proteins in Solution. Methods Mol Biol 2023; 2551:253-267. [PMID: 36310208 DOI: 10.1007/978-1-0716-2597-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Liquid-liquid phase separation (LLPS) is a reversible biological process that contributes to the formation of critical concentration of proteins, forming membraneless compartments that are physiologically and pathologically relevant. Several proteins have been shown to demix into liquid droplets under in vitro crowding conditions. These studies are mainly conducted in isolation using purified recombinant proteins. Recently, we used LLPS to study the association between two proteins that are co-aggregated in Alzheimer's disease brain, tau, and EFhd2. Here, we describe how we used LLPS to determine the molecular components that contribute to the transition of these two proteins from liquid droplets to solid-like structures.
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Affiliation(s)
- Irving E Vega
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA.
| | - Andrew Umstead
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
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11
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López-Palacios TP, Andersen JL. Kinase regulation by liquid–liquid phase separation. Trends Cell Biol 2022:S0962-8924(22)00260-4. [DOI: 10.1016/j.tcb.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
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12
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Protein interactions: anything new? Essays Biochem 2022; 66:821-830. [PMID: 36416856 PMCID: PMC9760424 DOI: 10.1042/ebc20220044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 11/24/2022]
Abstract
How do proteins interact in the cellular environment? Which interactions stabilize liquid-liquid phase separated condensates? Are the concepts, which have been developed for specific protein complexes also applicable to higher-order assemblies? Recent discoveries prompt for a universal framework for protein interactions, which can be applied across the scales of protein communities. Here, we discuss how our views on protein interactions have evolved from rigid structures to conformational ensembles of proteins and discuss the open problems, in particular related to biomolecular condensates. Protein interactions have evolved to follow changes in the cellular environment, which manifests in multiple modes of interactions between the same partners. Such cellular context-dependence requires multiplicity of binding modes (MBM) by sampling multiple minima of the interaction energy landscape. We demonstrate that the energy landscape framework of protein folding can be applied to explain this phenomenon, opening a perspective toward a physics-based, universal model for cellular protein behaviors.
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13
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Xing Y, Andrikopoulos N, Zhang Z, Sun Y, Ke PC, Ding F. Modulating Nanodroplet Formation En Route to Fibrillization of Amyloid Peptides with Designed Flanking Sequences. Biomacromolecules 2022; 23:4179-4191. [PMID: 36137260 PMCID: PMC9618360 DOI: 10.1021/acs.biomac.2c00642] [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: 11/28/2022]
Abstract
Soluble oligomers populating early amyloid aggregation can be regarded as nanodroplets of liquid-liquid phase separation (LLPS). Amyloid peptides typically contain hydrophobic aggregation-prone regions connected by hydrophilic linkers and flanking sequences, and such a sequence hydropathy pattern drives the formation of supramolecular structures in the nanodroplets and modulates subsequent fibrillization. Here, we studied LLPS and fibrillization of coarse-grained amyloid peptides with increasing flanking sequences. Nanodroplets assumed lamellar, cylindrical micellar, and spherical micellar structures with increasing peptide hydrophilic/hydrophobic ratios, and such morphologies governed subsequent fibrillization processes. Adding glycine-serine repeats as flanking sequences to Aβ16-22, the amyloidogenic core of amyloid-β, our computational predictions of morphological transitions were corroborated experimentally. The uncovered inter-relationships between the peptide sequence pattern, oligomer/nanodroplet morphology, and fibrillization pathway, kinetics, and structure may contribute to our understanding of pathogenic amyloidosis in aging, facilitate future efforts ameliorating amyloidosis through peptide engineering, and aid in the design of novel amyloid-based functional nanobiomaterials and nanocomposites.
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Affiliation(s)
- Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Nicholas Andrikopoulos
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Zhenzhen Zhang
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
- Department of Physics, Ningbo University, Ningbo 315211, China
| | - Pu Chun Ke
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
- Nanomedicine Center, The GBA National Institute for Nanotechnology Innovation, 136 Kaiyuan Avenue, Guangzhou, 510700, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
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14
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Tarczewska A, Bielak K, Zoglowek A, Sołtys K, Dobryszycki P, Ożyhar A, Różycka M. The Role of Intrinsically Disordered Proteins in Liquid–Liquid Phase Separation during Calcium Carbonate Biomineralization. Biomolecules 2022; 12:biom12091266. [PMID: 36139105 PMCID: PMC9496343 DOI: 10.3390/biom12091266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
Some animal organs contain mineralized tissues. These so-called hard tissues are mostly deposits of calcium salts, usually in the form of calcium phosphate or calcium carbonate. Examples of this include fish otoliths and mammalian otoconia, which are found in the inner ear, and they are an essential part of the sensory system that maintains body balance. The composition of ear stones is quite well known, but the role of individual components in the nucleation and growth of these biominerals is enigmatic. It is sure that intrinsically disordered proteins (IDPs) play an important role in this aspect. They have an impact on the shape and size of otoliths. It seems probable that IDPs, with their inherent ability to phase separate, also play a role in nucleation processes. This review discusses the major theories on the mechanisms of biomineral nucleation with a focus on the importance of protein-driven liquid–liquid phase separation (LLPS). It also presents the current understanding of the role of IDPs in the formation of calcium carbonate biominerals and predicts their potential ability to drive LLPS.
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15
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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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16
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Soliman AS, Umstead A, Grabinski T, Kanaan NM, Lee A, Ryan J, Lamp J, Vega IE. EFhd2 brain interactome reveals its association with different cellular and molecular processes. J Neurochem 2021; 159:992-1007. [PMID: 34543436 PMCID: PMC9552186 DOI: 10.1111/jnc.15517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 08/11/2021] [Accepted: 09/09/2021] [Indexed: 01/06/2023]
Abstract
EFhd2 is a conserved calcium-binding protein that is highly expressed in the central nervous system. We have shown that EFhd2 interacts with tau protein, a key pathological hallmark in Alzheimer's disease and related dementias. However, EFhd2's physiological and pathological functions in the brain are still poorly understood. To gain insights into its physiological function, we identified proteins that co-immunoprecipitated with EFhd2 from mouse forebrain and hindbrain, using tandem mass spectrometry (MS). In addition, quantitative mass spectrometry was used to detect protein abundance changes due to the deletion of the Efhd2 gene in mouse forebrain and hindbrain regions. Our data show that mouse EFhd2 is associated with cytoskeleton components, vesicle trafficking modulators, cellular stress response-regulating proteins, and metabolic proteins. Moreover, proteins associated with the cytoskeleton, vesicular transport, calcium signaling, stress response, and metabolic pathways showed differential abundance in Efhd2(-/-) mice. This study presents, for the first time, an EFhd2 brain interactome that it is associated with different cellular and molecular processes. These findings will help prioritize further studies to investigate the mechanisms by which EFhd2 modulates these processes in physiological and pathological conditions of the nervous system.
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Affiliation(s)
- Ahlam S Soliman
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA.,Neuroscience Program, Michigan State University, Grand Rapids, Michigan, USA.,Department of Clinical Pharmacy and Pharmacy Practice, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Andrew Umstead
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA.,Integrated Mass Spectrometry Unit, College of Human Medicine, Grand Rapids, Michigan, USA
| | - Tessa Grabinski
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA.,Neuroscience Program, Michigan State University, Grand Rapids, Michigan, USA.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
| | - Andy Lee
- NeuroInitiatives LLC, Jacksonville, Florida, USA
| | - John Ryan
- NeuroInitiatives LLC, Jacksonville, Florida, USA
| | - Jared Lamp
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA.,Integrated Mass Spectrometry Unit, College of Human Medicine, Grand Rapids, Michigan, USA
| | - Irving E Vega
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA.,Neuroscience Program, Michigan State University, Grand Rapids, Michigan, USA.,Integrated Mass Spectrometry Unit, College of Human Medicine, Grand Rapids, Michigan, USA.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA.,Department of Neurology, University of Michigan, Ann Arbor, Michigan, USA
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17
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Kang SG, Han ZZ, Daude N, McNamara E, Wohlgemuth S, Molina-Porcel L, Safar JG, Mok SA, Westaway D. Pathologic tau conformer ensembles induce dynamic, liquid-liquid phase separation events at the nuclear envelope. BMC Biol 2021; 19:199. [PMID: 34503506 PMCID: PMC8428099 DOI: 10.1186/s12915-021-01132-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/26/2021] [Indexed: 02/07/2023] Open
Abstract
Background The microtubule-associated protein tau forms aggregates in different neurodegenerative diseases called tauopathies. Prior work has shown that a single P301L mutation in tau gene, MAPT, can promote alternative tau folding pathways that correlate with divergent clinical diagnoses. Using progressive chemical denaturation, some tau preparations from the brain featured complex transitions starting at low concentrations of guanidine hydrochloride (GdnHCl) denaturant, indicating an ensemble of differently folded tau species called conformers. On the other hand, brain samples with abundant, tangle-like pathology had simple GdnHCl unfolding profile resembling the profile of fibrillized recombinant tau and suggesting a unitary conformer composition. In studies here we sought to understand tau conformer progression and potential relationships with condensed liquid states, as well as associated perturbations in cell biological processes. Results As starting material, we used brain samples from P301L transgenic mice containing tau conformer ensembles that unfolded at low GdnHCl concentrations and with signatures resembling brain material from P301L subjects presenting with language or memory problems. We seeded reporter cells expressing a soluble form of 4 microtubule-binding repeat tau fused to GFP or YFP reporter moieties, resulting in redistribution of dispersed fluorescence signals into focal assemblies that could fuse together and move within processes between adjacent cells. Nuclear envelope fluorescent tau signals and small fluorescent inclusions behaved as a demixed liquid phase, indicative of liquid-liquid phase separation (LLPS); these droplets exhibited spherical morphology, fusion events and could recover from photobleaching. Moreover, juxtanuclear tau assemblies were associated with disrupted nuclear transport and reduced cell viability in a stable cell line. Staining for thioflavin S (ThS) became more prevalent as tau-derived inclusions attained cross-sectional area greater than 3 μm2, indicating (i) a bipartite composition, (ii) in vivo progression of tau conformers, and (iii) that a mass threshold applying to demixed condensates may drive liquid-solid transitions. Conclusions Tau conformer ensembles characterized by denaturation at low GdnHCl concentration templated the production of condensed droplets in living cells. These species exhibit dynamic changes and develop in vivo, and the larger ThS-positive assemblies may represent a waystation to arrive at intracellular fibrillar tau inclusions seen in end-stage genetic tauopathies. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01132-y.
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Affiliation(s)
- Sang-Gyun Kang
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada
| | - Zhuang Zhuang Han
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Nathalie Daude
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada
| | - Emily McNamara
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Serene Wohlgemuth
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada
| | | | - Jiri G Safar
- Department of Neurology and Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Sue-Ann Mok
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - David Westaway
- Centre for Prions and Protein Folding Diseases, University of Alberta, 204 Brain and Aging Research Building, Edmonton, AB, T6G 2 M8, Canada. .,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada. .,Division of Neurology, University of Alberta, Edmonton, AB, Canada.
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18
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Wang D, Huang X, Yan L, Zhou L, Yan C, Wu J, Su Z, Huang Y. The Structure Biology of Tau and Clue for Aggregation Inhibitor Design. Protein J 2021; 40:656-668. [PMID: 34401998 DOI: 10.1007/s10930-021-10017-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2021] [Indexed: 12/22/2022]
Abstract
Tau is a microtubule-associated protein that is mainly expressed in central and peripheral nerve systems. Tau binds to tubulin and regulates assembly and stabilization of microtubule, thus playing a critical role in neuron morphology, axon development and navigation. Tau is highly stable under normal conditions; however, there are several factors that can induce or promote aggregation of tau, forming neurofibrillary tangles. Neurofibrillary tangles are toxic to neurons, which may be related to a series of neurodegenerative diseases including Alzheimer's disease. Thus, tau is widely accepted as an important therapeutic target for neurodegenerative diseases. While the monomeric structure of tau is highly disordered, the aggregate structure of tau is formed by closed packing of β-stands. Studies on the structure of tau and the structural transition mechanism provide valuable information on the occurrence, development, and therapy of tauopathies. In this review, we summarize recent progress on the structural investigation of tau and based on which we discuss aggregation inhibitor design.
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Affiliation(s)
- Dan Wang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Xianlong Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Lu Yan
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Luoqi Zhou
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Chang Yan
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Jinhu Wu
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China. .,Hubei Key Laboratory of Industrial Microbiology, Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei, China.
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19
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Jiang X, Ho DBT, Mahe K, Mia J, Sepulveda G, Antkowiak M, Jiang L, Yamada S, Jao LE. Condensation of pericentrin proteins in human cells illuminates phase separation in centrosome assembly. J Cell Sci 2021; 134:jcs258897. [PMID: 34308971 PMCID: PMC8349556 DOI: 10.1242/jcs.258897] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/08/2021] [Indexed: 11/24/2022] Open
Abstract
At the onset of mitosis, centrosomes expand the pericentriolar material (PCM) to maximize their microtubule-organizing activity. This step, termed centrosome maturation, ensures proper spindle organization and faithful chromosome segregation. However, as the centrosome expands, how PCM proteins are recruited and held together without membrane enclosure remains elusive. We found that endogenously expressed pericentrin (PCNT), a conserved PCM scaffold protein, condenses into dynamic granules during late G2/early mitosis before incorporating into mitotic centrosomes. Furthermore, the N-terminal portion of PCNT, enriched with conserved coiled-coils (CCs) and low-complexity regions (LCRs), phase separates into dynamic condensates that selectively recruit PCM proteins and nucleate microtubules in cells. We propose that CCs and LCRs, two prevalent sequence features in the centrosomal proteome, are preserved under evolutionary pressure in part to mediate liquid-liquid phase separation, a process that bestows upon the centrosome distinct properties critical for its assembly and functions.
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Affiliation(s)
- Xueer Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Dac Bang Tam Ho
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Karan Mahe
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Jennielee Mia
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Guadalupe Sepulveda
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Mark Antkowiak
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Linhao Jiang
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
| | - Soichiro Yamada
- Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA
| | - Li-En Jao
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA
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20
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Rai SK, Savastano A, Singh P, Mukhopadhyay S, Zweckstetter M. Liquid-liquid phase separation of tau: From molecular biophysics to physiology and disease. Protein Sci 2021; 30:1294-1314. [PMID: 33930220 PMCID: PMC8197432 DOI: 10.1002/pro.4093] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 12/14/2022]
Abstract
Biomolecular condensation via liquid-liquid phase separation (LLPS) of intrinsically disordered proteins/regions (IDPs/IDRs), with and without nucleic acids, has drawn widespread interest due to the rapidly unfolding role of phase-separated condensates in a diverse range of cellular functions and human diseases. Biomolecular condensates form via transient and multivalent intermolecular forces that sequester proteins and nucleic acids into liquid-like membrane-less compartments. However, aberrant phase transitions into gel-like or solid-like aggregates might play an important role in neurodegenerative and other diseases. Tau, a microtubule-associated neuronal IDP, is involved in microtubule stabilization, regulates axonal outgrowth and transport in neurons. A growing body of evidence indicates that tau can accomplish some of its cellular activities via LLPS. However, liquid-to-solid transition resulting in the abnormal aggregation of tau is associated with neurodegenerative diseases. The physical chemistry of tau is crucial for governing its propensity for biomolecular condensation which is governed by various intermolecular and intramolecular interactions leading to simple one-component and complex multi-component condensates. In this review, we aim at capturing the current scientific state in unveiling the intriguing molecular mechanism of phase separation of tau. We particularly focus on the amalgamation of existing and emerging biophysical tools that offer unique spatiotemporal resolutions on a wide range of length- and time-scales. We also discuss the link between quantitative biophysical measurements and novel biological insights into biomolecular condensation of tau. We believe that this account will provide a broad and multidisciplinary view of phase separation of tau and its association with physiology and disease.
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Affiliation(s)
- Sandeep K. Rai
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Adriana Savastano
- Research group Translational Structural BiologyGerman Center for Neurodegenerative Diseases (DZNE)GöttingenGermany
| | - Priyanka Singh
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical SciencesIndian Institute of Science Education and Research (IISER)MohaliIndia
| | - Markus Zweckstetter
- Research group Translational Structural BiologyGerman Center for Neurodegenerative Diseases (DZNE)GöttingenGermany
- Department for NMR‐based Structural BiologyMax Planck Institute for Biophysical ChemistryGöttingenGermany
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21
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Zeng Y, Yang J, Zhang B, Gao M, Su Z, Huang Y. The structure and phase of tau: from monomer to amyloid filament. Cell Mol Life Sci 2021; 78:1873-1886. [PMID: 33078207 PMCID: PMC11073437 DOI: 10.1007/s00018-020-03681-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/20/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
Tau is a microtubule-associated protein involved in regulation of assembly and spatial organization of microtubule in neurons. However, in pathological conditions, tau monomers assemble into amyloid filaments characterized by the cross-β structures in a number of neurodegenerative diseases known as tauopathies. In this review, we summarize recent progression on the characterization of structures of tau monomer and filament, as well as the dynamic liquid droplet assembly. Our aim is to reveal how post-translational modifications, amino acid mutations, and interacting molecules modulate the conformational ensemble of tau monomer, and how they accelerate or inhibit tau assembly into aggregates. Structure-based aggregation inhibitor design is also discussed in the context of dynamics and heterogeneity of tau structures.
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Affiliation(s)
- Yifan Zeng
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Jing Yang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Bailing Zhang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Meng Gao
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, China.
- Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, China.
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22
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Umstead A, Soliman AS, Lamp J, Vega IE. Validation of recombinant human protein purified from bacteria: An important step to increase scientific rigor. Anal Biochem 2020; 611:113999. [DOI: 10.1016/j.ab.2020.113999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/17/2020] [Indexed: 11/29/2022]
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23
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Kang SG, Eskandari-Sedighi G, Hromadkova L, Safar JG, Westaway D. Cellular Biology of Tau Diversity and Pathogenic Conformers. Front Neurol 2020; 11:590199. [PMID: 33304310 PMCID: PMC7693435 DOI: 10.3389/fneur.2020.590199] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/05/2020] [Indexed: 12/12/2022] Open
Abstract
Tau accumulation is a prominent feature in a variety of neurodegenerative disorders and remarkable effort has been expended working out the biochemistry and cell biology of this cytoplasmic protein. Tau's wayward properties may derive from germline mutations in the case of frontotemporal lobar degeneration (FTLD-MAPT) but may also be prompted by less understood cues—perhaps environmental or from molecular damage as a consequence of chronological aging—in the case of idiopathic tauopathies. Tau properties are undoubtedly affected by its covalent structure and in this respect tau protein is not only subject to changes in length produced by alternative splicing and endoproteolysis, but different types of posttranslational modifications that affect different amino acid residues. Another layer of complexity concerns alternate conformations—“conformers”—of the same covalent structures; in vivo conformers can encompass soluble oligomeric species, ramified fibrillar structures evident by light and electron microscopy and other forms of the protein that have undergone liquid-liquid phase separation to make demixed liquid droplets. Biological concepts based upon conformers have been charted previously for templated replication mechanisms for prion proteins built of the PrP polypeptide; these are now providing useful explanations to feature tau pathobiology, including how this protein accumulates within cells and how it can exhibit predictable patterns of spread across different neuroanatomical regions of an affected brain. In sum, the documented, intrinsic heterogeneity of tau forms and conformers now begins to speak to a fundamental basis for diversity in clinical presentation of tauopathy sub-types. In terms of interventions, emphasis upon subclinical events may be worthwhile, noting that irrevocable cell loss and ramified protein assemblies feature at end-stage tauopathy, whereas earlier events may offer better opportunities for diverting pathogenic processes. Nonetheless, the complexity of tau sub-types, which may be present even within intermediate disease stages, likely mitigates against one-size-fits-all therapeutic strategies and may require a suite of interventions. We consider the extent to which animal models of tauopathy can be reasonably enrolled in the campaign to produce such interventions and to slow the otherwise inexorable march of disease progression.
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Affiliation(s)
- Sang-Gyun Kang
- Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada
| | | | - Lenka Hromadkova
- Department of Neurology and Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - Jiri G Safar
- Department of Neurology and Pathology, Case Western Reserve University, Cleveland, OH, United States
| | - David Westaway
- Center for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB, Canada.,Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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24
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Liquid-Liquid Phase Separation in Crowded Environments. Int J Mol Sci 2020; 21:ijms21165908. [PMID: 32824618 PMCID: PMC7460619 DOI: 10.3390/ijms21165908] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 08/13/2020] [Indexed: 12/23/2022] Open
Abstract
Biomolecular condensates play a key role in organizing cellular fluids such as the cytoplasm and nucleoplasm. Most of these non-membranous organelles show liquid-like properties both in cells and when studied in vitro through liquid–liquid phase separation (LLPS) of purified proteins. In general, LLPS of proteins is known to be sensitive to variations in pH, temperature and ionic strength, but the role of crowding remains underappreciated. Several decades of research have shown that macromolecular crowding can have profound effects on protein interactions, folding and aggregation, and it must, by extension, also impact LLPS. However, the precise role of crowding in LLPS is far from trivial, as most condensate components have a disordered nature and exhibit multiple weak attractive interactions. Here, we discuss which factors determine the scope of LLPS in crowded environments, and we review the evidence for the impact of macromolecular crowding on phase boundaries, partitioning behavior and condensate properties. Based on a comparison of both in vivo and in vitro LLPS studies, we propose that phase separation in cells does not solely rely on attractive interactions, but shows important similarities to segregative phase separation.
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25
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Liquid-liquid phase separation induces pathogenic tau conformations in vitro. Nat Commun 2020; 11:2809. [PMID: 32499559 PMCID: PMC7272632 DOI: 10.1038/s41467-020-16580-3] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/08/2020] [Indexed: 01/21/2023] Open
Abstract
Formation of membrane-less organelles via liquid-liquid phase separation is one way cells meet the biological requirement for spatiotemporal regulation of cellular components and reactions. Recently, tau, a protein known for its involvement in Alzheimer’s disease and other tauopathies, was found to undergo liquid–liquid phase separation making it one of several proteins associated with neurodegenerative diseases to do so. Here, we demonstrate that tau forms dynamic liquid droplets in vitro at physiological protein levels upon molecular crowding in buffers that resemble physiological conditions. Tau droplet formation is significantly enhanced by disease-associated modifications, including the AT8 phospho-epitope and the P301L tau mutation linked to an inherited tauopathy. Moreover, tau droplet dynamics are significantly reduced by these modified forms of tau. Extended phase separation promoted a time-dependent adoption of toxic conformations and oligomerization, but not filamentous aggregation. P301L tau protein showed the greatest oligomer formation following extended phase separation. These findings suggest that phase separation of tau may facilitate the formation of non-filamentous pathogenic tau conformations. Tau plays an important role in tauopathies and undergoes liquid-liquid phase separation (LLPS). The authors show that disease-related P301L mutant and phosphomimic (S199E/S202E/T205E) tau enhance LLPS in vitro at physiological levels, and using specific antibodies, that tau LLPS leads to pathological conformations such as N-terminal exposure and oligomeric species.
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