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Zheng H, Sun H, Cai Q, Tai HC. The Enigma of Tau Protein Aggregation: Mechanistic Insights and Future Challenges. Int J Mol Sci 2024; 25:4969. [PMID: 38732197 PMCID: PMC11084794 DOI: 10.3390/ijms25094969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 04/20/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Tau protein misfolding and aggregation are pathological hallmarks of Alzheimer's disease and over twenty neurodegenerative disorders. However, the molecular mechanisms of tau aggregation in vivo remain incompletely understood. There are two types of tau aggregates in the brain: soluble aggregates (oligomers and protofibrils) and insoluble filaments (fibrils). Compared to filamentous aggregates, soluble aggregates are more toxic and exhibit prion-like transmission, providing seeds for templated misfolding. Curiously, in its native state, tau is a highly soluble, heat-stable protein that does not form fibrils by itself, not even when hyperphosphorylated. In vitro studies have found that negatively charged molecules such as heparin, RNA, or arachidonic acid are generally required to induce tau aggregation. Two recent breakthroughs have provided new insights into tau aggregation mechanisms. First, as an intrinsically disordered protein, tau is found to undergo liquid-liquid phase separation (LLPS) both in vitro and inside cells. Second, cryo-electron microscopy has revealed diverse fibrillar tau conformations associated with different neurodegenerative disorders. Nonetheless, only the fibrillar core is structurally resolved, and the remainder of the protein appears as a "fuzzy coat". From this review, it appears that further studies are required (1) to clarify the role of LLPS in tau aggregation; (2) to unveil the structural features of soluble tau aggregates; (3) to understand the involvement of fuzzy coat regions in oligomer and fibril formation.
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Affiliation(s)
| | | | | | - Hwan-Ching Tai
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Innovation Platform for Industry-Education Integration in Vaccine Research, School of Public Health, Xiamen University, Xiamen 361102, China
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2
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Buchholz S, Zempel H. The six brain-specific TAU isoforms and their role in Alzheimer's disease and related neurodegenerative dementia syndromes. Alzheimers Dement 2024; 20:3606-3628. [PMID: 38556838 PMCID: PMC11095451 DOI: 10.1002/alz.13784] [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: 12/08/2023] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 04/02/2024]
Abstract
INTRODUCTION Alternative splicing of the human MAPT gene generates six brain-specific TAU isoforms. Imbalances in the TAU isoform ratio can lead to neurodegenerative diseases, underscoring the need for precise control over TAU isoform balance. Tauopathies, characterized by intracellular aggregates of hyperphosphorylated TAU, exhibit extensive neurodegeneration and can be classified by the TAU isoforms present in pathological accumulations. METHODS A comprehensive review of TAU and related dementia syndromes literature was conducted using PubMed, Google Scholar, and preprint server. RESULTS While TAU is recognized as key driver of neurodegeneration in specific tauopathies, the contribution of the isoforms to neuronal function and disease development remains largely elusive. DISCUSSION In this review we describe the role of TAU isoforms in health and disease, and stress the importance of comprehending and studying TAU isoforms in both, physiological and pathological context, in order to develop targeted therapeutic interventions for TAU-associated diseases. HIGHLIGHTS MAPT splicing is tightly regulated during neuronal maturation and throughout life. TAU isoform expression is development-, cell-type and brain region specific. The contribution of TAU to neurodegeneration might be isoform-specific. Ineffective TAU-based therapies highlight the need for specific targeting strategies.
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Affiliation(s)
- Sarah Buchholz
- Institute of Human GeneticsFaculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
- Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
- Present address:
Department Schaefer, Neurobiology of AgeingMax Planck Institute for Biology of AgeingCologneGermany
| | - Hans Zempel
- Institute of Human GeneticsFaculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
- Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
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3
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Huang Y, Wen J, Ramirez LM, Gümüşdil E, Pokhrel P, Man VH, Ye H, Han Y, Liu Y, Li P, Su Z, Wang J, Mao H, Zweckstetter M, Perrett S, Wu S, Gao M. Methylene blue accelerates liquid-to-gel transition of tau condensates impacting tau function and pathology. Nat Commun 2023; 14:5444. [PMID: 37673952 PMCID: PMC10482834 DOI: 10.1038/s41467-023-41241-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 08/27/2023] [Indexed: 09/08/2023] Open
Abstract
Preventing tau aggregation is a potential therapeutic strategy in Alzheimer's disease and other tauopathies. Recently, liquid-liquid phase separation has been found to facilitate the formation of pathogenic tau conformations and fibrillar aggregates, although many aspects of the conformational transitions of tau during the phase transition process remain unknown. Here, we demonstrate that the tau aggregation inhibitor methylene blue promotes tau liquid-liquid phase separation and accelerates the liquid-to-gel transition of tau droplets independent of the redox activity of methylene blue. We further show that methylene blue inhibits the conversion of tau droplets into fibrils and reduces the cytotoxicity of tau aggregates. Although gelation slows down the mobility of tau and tubulin, it does not impair microtubule assembly within tau droplets. These findings suggest that methylene blue inhibits tau amyloid fibrillization and accelerates tau droplet gelation via distinct mechanisms, thus providing insights into the activity of tau aggregation inhibitors in the context of phase transition.
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Affiliation(s)
- Yongqi Huang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China.
| | - Jitao Wen
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
- University of the Chinese Academy of Sciences, 100049, Beijing, China
| | - Lisa-Marie Ramirez
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Eymen Gümüşdil
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Department of Molecular Biology and Genetics, Gebze Technical University, 41400, Gebze Çayirova, Kocaeli, Turkey
| | - Pravin Pokhrel
- Department of Chemistry & Biochemistry, Advanced Materials and Liquid Crystal Institute, Department of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - Viet H Man
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Haiqiong Ye
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China
| | - Yue Han
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China
| | - Yunfei Liu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China
| | - Ping Li
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China
| | - Zhengding Su
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China
| | - Junmei Wang
- Department of Pharmaceutical Sciences and Computational Chemical Genomics Screening Center, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Hanbin Mao
- Department of Chemistry & Biochemistry, Advanced Materials and Liquid Crystal Institute, Department of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077, Göttingen, Germany
| | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
- University of the Chinese Academy of Sciences, 100049, Beijing, China
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
- University of the Chinese Academy of Sciences, 100049, Beijing, China.
| | - Meng Gao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, 430068, Wuhan, China.
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4
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Boyko S, Surewicz WK. Domain-specific modulatory effects of phosphomimetic substitutions on liquid-liquid phase separation of tau protein. J Biol Chem 2023; 299:104722. [PMID: 37075845 PMCID: PMC10199205 DOI: 10.1016/j.jbc.2023.104722] [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: 12/03/2022] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
Aggregation of tau is one of the major pathogenic events in Alzheimer's disease and several other neurodegenerative disorders. Recent reports demonstrated that tau can condense into liquid droplets that undergo time-dependent transition to a solid-like state, suggesting that liquid condensates may be on the pathway to pathological aggregation of tau. While hyperphosphorylation is a key feature of tau isolated from brains of patients with Alzheimer's disease and other tauopathies, the mechanistic role of phosphorylation in tau liquid-liquid phase separation (LLPS) remains largely unexplored. In an attempt to bridge this gap, here we performed systematic studies by introducing phosphomimetic substitutions of Ser/Thr residues with negatively charged Asp/Glu residues in different regions of the protein. Our data indicate that the phosphorylation patterns that increase the polarization of charge distribution in full-length tau (tau441) promote protein LLPS, whereas those that decrease charge polarization have an opposite effect. Overall, this study further supports the notion that tau LLPS is driven by attractive intermolecular electrostatic interactions between the oppositely charged domains. We also show that the phosphomimetic tau variants with low intrinsic propensity for LLPS can be efficiently recruited to droplets formed by the variants with high LLPS propensity. Furthermore, the present data demonstrate that phosphomimetic substitutions have a major effect on time-dependent material properties of tau droplets, generally slowing down their aging. The latter effect is most dramatic for the tau variant with substitutions within the repeat domain, which correlates with the decreased fibrillation rate of this variant.
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Affiliation(s)
- Solomiia Boyko
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Witold K Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA.
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5
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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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6
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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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7
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Donau C, Späth F, Stasi M, Bergmann AM, Boekhoven J. Phase Transitions in Chemically Fueled, Multiphase Complex Coacervate Droplets. Angew Chem Int Ed Engl 2022; 61:e202211905. [PMID: 36067054 PMCID: PMC9828839 DOI: 10.1002/anie.202211905] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Indexed: 01/12/2023]
Abstract
Membraneless organelles are droplets in the cytosol that are regulated by chemical reactions. Increasing studies suggest that they are internally organized. However, how these subcompartments are regulated remains elusive. Herein, we describe a complex coacervate-based model composed of two polyanions and a short peptide. With a chemical reaction cycle, we control the affinity of the peptide for the polyelectrolytes leading to distinct regimes inside the phase diagram. We study the transitions from one regime to another and identify new transitions that can only occur under kinetic control. Finally, we show that the chemical reaction cycle controls the liquidity of the droplets offering insights into how active processes inside cells play an important role in tuning the liquid state of membraneless organelles. Our work demonstrates that not only thermodynamic properties but also kinetics should be considered in the organization of multiple phases in droplets.
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Affiliation(s)
- Carsten Donau
- Department of ChemistryTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
| | - Fabian Späth
- Department of ChemistryTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
| | - Michele Stasi
- Department of ChemistryTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
| | - Alexander M. Bergmann
- Department of ChemistryTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
| | - Job Boekhoven
- Department of ChemistryTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
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8
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Phase separation of the microtubule-associated protein tau. Essays Biochem 2022; 66:1013-1021. [PMID: 36251053 DOI: 10.1042/ebc20220066] [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: 08/30/2022] [Revised: 08/30/2022] [Accepted: 09/29/2022] [Indexed: 11/17/2022]
Abstract
The aggregation and misfolding of the neuronal microtubule-associated protein tau is closely linked to the pathology of Alzheimer's disease and several other neurodegenerative diseases. Recent evidence suggest that tau undergoes liquid-liquid phase separation in vitro and forms or associates with membrane-less organelles in cells. Biomolecular condensation driven by phase separation can influence the biological activities of tau including its ability to polymerize tubulin into microtubules. In addition, the high concentrations that tau can reach in biomolecular condensates provide a mechanism to promote its aggregation and the formation of amyloid fibrils potentially contributing to the pathology of different tauopathies. Here, the authors discuss the role of tau phase separation in physiology and disease.
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9
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Liquid-Liquid Phase Separation Promotes Protein Aggregation and Its Implications in Ferroptosis in Parkinson’s Disease Dementia. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7165387. [PMID: 36246407 PMCID: PMC9560807 DOI: 10.1155/2022/7165387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/07/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022]
Abstract
The pathological features of PDD are represented by dopaminergic neuronal death and intracellular α-synuclein (α-syn) aggregation. The interaction of iron accumulation with α-syn and tau was further explored as an essential pathological mechanism of PDD. However, the links and mechanisms between these factors remain unclear. Studies have shown that the occurrence and development of neurodegenerative diseases such as PDD are closely related to the separation of abnormal phases. Substances such as proteins can form droplets through liquid-liquid phase separation (LLPS) under normal physiological conditions and even undergo further liquid-solid phase transitions to form solid aggregates under disease or regulatory disorders, leading to pathological phenomena. By analyzing the existing literature, we propose that LLPS is the crucial mechanism causing abnormal accumulation of α-syn, tau, and other proteins in PDD, and its interaction with iron metabolism disorder is the key factor driving ferroptosis in PDD. Therefore, we believe that LLPS can serve as one of the means to explain the pathological mechanism of PDD. Determining the significance of LLPS in neurodegenerative diseases such as PDD will stimulate interest in research into treatments based on interference with abnormal LLPS.
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Ye H, Han Y, Li P, Su Z, Huang Y. The Role of Post-Translational Modifications on the Structure and Function of Tau Protein. J Mol Neurosci 2022; 72:1557-1571. [PMID: 35325356 DOI: 10.1007/s12031-022-02002-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/14/2022] [Indexed: 12/14/2022]
Abstract
Involving addition of chemical groups or protein units to specific residues of the target protein, post-translational modifications (PTMs) alter the charge, hydrophobicity, and conformation of a protein, which in tune influences protein function, protein - protein interaction, and protein aggregation. While the occurrence of PTMs is dynamic and subject to regulations, conformational disorder of the target protein facilitates PTMs. The microtubule-associated protein tau is a typical intrinsically disordered protein that undergoes a variety of PTMs including phosphorylation, acetylation, ubiquitination, methylation, and oxidation. Accumulated evidence shows that these PTMs play a critical role in regulating tau-microtubule interaction, tau localization, tau degradation and aggregation, and reinforces the correlation between tau PTMs and pathogenesis of neurodegenerative disease. Here, we review tau PTMs with an emphasis on their influence on tau structure. With available biophysical characterization results, we describe how PTMs induce conformational changes in tau monomer and regulate tau aggregation. Compared to functional analysis of tau PTMs, biophysical characterization of tau PTMs is lagging. While it is challenging, characterizing the specific effects of PTMs on tau conformation and interaction is indispensable to unravel the tau PTM code.
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Affiliation(s)
- Haiqiong Ye
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China.,Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Yue Han
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China.,Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Ping Li
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China.,Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China.,Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China.,Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan, 430068, China. .,Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China. .,Department of Biological Engineering, Hubei University of Technology, Wuhan, 430068, China.
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11
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Tau liquid-liquid phase separation in neurodegenerative diseases. Trends Cell Biol 2022; 32:611-623. [PMID: 35181198 DOI: 10.1016/j.tcb.2022.01.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 12/19/2022]
Abstract
Aggregation of the microtubule-associated protein tau plays a major role in Alzheimer's disease and several other neurodegenerative disorders. An exciting recent development is the finding that, akin to some other proteins associated with neurodegenerative disease, tau has a high propensity to condensate via the mechanism of liquid-liquid phase separation (LLPS). Here, we discuss the evidence for tau LLPS in vitro, the molecular mechanisms of this reaction, and the role of post-translational modifications and pathogenic mutations in tau phase separation. We also discuss recent studies on tau LLPS in cells and the insights these studies provide regarding the link between LLPS and neurodegeneration in tauopathies.
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