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Lester E, Parker R. Tau, RNA, and RNA-Binding Proteins: Complex Interactions in Health and Neurodegenerative Diseases. Neuroscientist 2024; 30:458-472. [PMID: 36892034 DOI: 10.1177/10738584231154551] [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: 03/10/2023]
Abstract
The tau protein is a key contributor to multiple neurodegenerative diseases. The pathology of tau is thought to be related to tau's propensity to form self-templating fibrillar structures that allow tau fibers to propagate in the brain by prion-like mechanisms. Unresolved issues with respect to tau pathology are how the normal function of tau and its misregulation contribute to disease, how cofactors and cellular organelles influence the initiation and propagation of tau fibers, and determining the mechanism of tau toxicity. Herein, we review the connection between tau and degenerative diseases, the basis for tau fibrilization, and how that process interacts with cellular molecules and organelles. One emerging theme is that tau interacts with RNA and RNA-binding proteins, normally and in pathologic aggregates, which may provide insight into alterations in RNA regulation observed in disease.
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Affiliation(s)
- Evan Lester
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA
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2
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Comptdaer T, Tardivel M, Schirmer C, Buée L, Galas MC. Cell redistribution of G quadruplex-structured DNA is associated with morphological changes of nuclei and nucleoli in neurons during tau pathology progression. Brain Pathol 2024:e13262. [PMID: 38649330 DOI: 10.1111/bpa.13262] [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: 01/06/2024] [Accepted: 04/02/2024] [Indexed: 04/25/2024] Open
Abstract
While the double helical structure has long been its iconic representation, DNA is structurally dynamic and can adopt alternative secondary configurations. Specifically, guanine-rich DNA sequences can fold in guanine quadruplexes (G4) structures. These G4 play pivotal roles as regulators of gene expression and genomic stability, and influence protein homeostasis. Despite their significance, the association of G4 with neurodegenerative diseases such as Alzheimer's disease (AD) has been underappreciated. Recent findings have identified DNA sequences predicted to form G4 in sarkosyl-insoluble aggregates from AD brains, questioning the involvement of G4-structured DNA (G4 DNA) in the pathology. Using immunofluorescence coupled to confocal microscopy analysis we investigated the impact of tau pathology, a hallmark of tauopathies including AD, on the distribution of G4 DNA in murine neurons and its relevance to AD brains. In healthy neurons, G4 DNA is detected in nuclei with a notable presence in nucleoli. However, in a transgenic mouse model of tau pathology (THY-Tau22), early stages of the disease exhibit an impairment in the nuclear distribution of G4 DNA. In addition, G4 DNA accumulates in the cytoplasm of neurons exhibiting oligomerized tau and oxidative DNA damage. This altered distribution persists in the later stage of the pathology when larger tau aggregates are present. Still cytoplasmic deposition of G4 DNA does not appear to be a critical factor in the tau aggregation process. Similar patterns are observed in neurons from the AD cortex. Furthermore, the disturbance in G4 DNA distribution is associated with various changes in the size of neuronal nuclei and nucleoli, indicative of responses to stress and the activation of pro-survival mechanisms. Our results shed light on a significant impact of tau pathology on the dynamics of G4 DNA and on nuclear and nucleolar mechanobiology in neurons. These findings reveal new dimensions in the etiopathogenesis of tauopathies.
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Affiliation(s)
- Thomas Comptdaer
- University of Lille, Inserm, CHU Lille, CNRS, LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Meryem Tardivel
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, US41-UAR 2014-PLBS, Lille, France
| | - Claire Schirmer
- University of Lille, Inserm, CHU Lille, CNRS, LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Luc Buée
- University of Lille, Inserm, CHU Lille, CNRS, LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Marie-Christine Galas
- University of Lille, Inserm, CHU Lille, CNRS, LilNCog-Lille Neuroscience and Cognition, Lille, France
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3
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Litberg TJ, Horowitz S. Roles of Nucleic Acids in Protein Folding, Aggregation, and Disease. ACS Chem Biol 2024; 19:809-823. [PMID: 38477936 PMCID: PMC11149768 DOI: 10.1021/acschembio.3c00695] [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: 03/14/2024]
Abstract
The role of nucleic acids in protein folding and aggregation is an area of continued research, with relevance to understanding both basic biological processes and disease. In this review, we provide an overview of the trajectory of research on both nucleic acids as chaperones and their roles in several protein misfolding diseases. We highlight key questions that remain on the biophysical and biochemical specifics of how nucleic acids have large effects on multiple proteins' folding and aggregation behavior and how this pertains to multiple protein misfolding diseases.
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Affiliation(s)
- Theodore J. Litberg
- Department of Chemistry & Biochemistry and The Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, 80208, USA
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Scott Horowitz
- Department of Chemistry & Biochemistry and The Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, 80208, USA
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4
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Powell WC, Nahum M, Pankratz K, Herlory M, Greenwood J, Poliyenko D, Holland P, Jing R, Biggerstaff L, Stowell MHB, Walczak MA. Post-Translational Modifications Control Phase Transitions of Tau. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.08.583040. [PMID: 38559065 PMCID: PMC10979912 DOI: 10.1101/2024.03.08.583040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The self-assembly of Tau(297-391) into filaments, which mirror the structures observed in Alzheimer's disease (AD) brains, raises questions about the role of AD-specific post-translational modifications (PTMs) in the formation of paired helical filaments (PHFs). To investigate this, we developed a synthetic approach to produce Tau(291-391) featuring N-acetyllysine, phosphoserine, phosphotyrosine, and N-glycosylation at positions commonly modified in post-mortem AD brains, thus facilitating the study of their roles in Tau pathology. Using transmission electron microscopy (TEM), cryo-electron microscopy (cryo-EM), and a range of optical microscopy techniques, we discovered that these modifications generally hinder the in vitro assembly of Tau into PHFs. Interestingly, while acetylation's effect on Tau assembly displayed variability, either promoting or inhibiting phase transitions in the context of cofactor free aggregation, heparin-induced aggregation, and RNA-mediated liquid-liquid phase separation (LLPS), phosphorylation uniformly mitigated these processes. Our observations suggest that PTMs, particularly those situated outside the fibril's rigid core are pivotal in the nucleation of PHFs. Moreover, in scenarios involving heparin-induced aggregation leading to the formation of heterogeneous aggregates, most AD-specific PTMs, except for K311, appeared to decelerate the aggregation process. The impact of acetylation on RNA-induced LLPS was notably site-dependent, exhibiting both facilitative and inhibitory effects, whereas phosphorylation consistently reduced LLPS across all proteoforms examined. These insights underscore the complex interplay between site-specific PTMs and environmental factors in modulating Tau aggregation kinetics, enhancing our understanding of the molecular underpinnings of Tau pathology in AD and highlighting the critical role of PTMs located outside the ordered filament core in driving the self-assembly of Tau into PHF structures.
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Affiliation(s)
- Wyatt C. Powell
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - McKinley Nahum
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Karl Pankratz
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Morgane Herlory
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - James Greenwood
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Darya Poliyenko
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309, United States
| | - Patrick Holland
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Ruiheng Jing
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Luke Biggerstaff
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Michael H. B. Stowell
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309, United States
| | - Maciej A. Walczak
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
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5
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Ashrafi-Kooshk MR, Norouzi F, Zare Karizak A, Ahmadian S, Moosavi-Movahedi AA, Riazi G. Crosstalk between tau protein autoproteolysis and amyloid fibril formation. Int J Biol Macromol 2024; 262:129953. [PMID: 38325678 DOI: 10.1016/j.ijbiomac.2024.129953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/25/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
Tau cleavage has been shown to have a significant effect on protein aggregation. Tau truncation results in the formation of aggregation-prone fragments leading to toxic aggregates and also causes the formation of harmful fragments that do not aggregate. Thus, targeting proteolysis of tau would be beneficial for the development of therapeutics for Alzheimer's disease and related tauopathies. In this study, amino-terminal quantification and ThT fluorimetry were respectively used to analyze the kinetics of tau fragmentation and fibril formation. SDS-PAGE analysis of tau protein incubated with a disulfide-reducing agent demonstrated that the cysteines of tau have a crucial role in the fibrillation and autoproteolysis. However, the structures converted to amyloid fibrils were different with conformations that led to autoproteolysis. The quantification of the amino terminal indicated that the double-disulfide parallel structures formed in the presence of heparin did not have protease activity. The survey of possible tau disulfide-mediated dimer configurations suggested that the non-register single disulfide bound conformations were involved in the tau autoproteolysis process. Moreover, the inhibition of autoproteolysis resulted in the increment of aggregation rate; hence it seems that the tau auto-cleavage is the cellular defense mechanism against protein fibrillation.
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Affiliation(s)
| | - Fatemeh Norouzi
- Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, Tehran, Iran
| | - Ashkan Zare Karizak
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Gholamhossein Riazi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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6
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Granholm AC, Hamlett ED. The Role of Tau Pathology in Alzheimer's Disease and Down Syndrome. J Clin Med 2024; 13:1338. [PMID: 38592182 PMCID: PMC10932364 DOI: 10.3390/jcm13051338] [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: 01/24/2024] [Revised: 02/10/2024] [Accepted: 02/20/2024] [Indexed: 04/10/2024] Open
Abstract
Background: Individuals with Down syndrome (DS) exhibit an almost complete penetrance of Alzheimer's disease (AD) pathology but are underrepresented in clinical trials for AD. The Tau protein is associated with microtubule function in the neuron and is crucial for normal axonal transport. In several different neurodegenerative disorders, Tau misfolding leads to hyper-phosphorylation of Tau (p-Tau), which may seed pathology to bystander cells and spread. This review is focused on current findings regarding p-Tau and its potential to seed pathology as a "prion-like" spreader. It also considers the consequences of p-Tau pathology leading to AD, particularly in individuals with Down syndrome. Methods: Scopus (SC) and PubMed (PM) were searched in English using keywords "tau AND seeding AND brain AND down syndrome". A total of 558 SC or 529 PM potentially relevant articles were identified, of which only six SC or three PM articles mentioned Down syndrome. This review was built upon the literature and the recent findings of our group and others. Results: Misfolded p-Tau isoforms are seeding competent and may be responsible for spreading AD pathology. Conclusions: This review demonstrates recent work focused on understanding the role of neurofibrillary tangles and monomeric/oligomeric Tau in the prion-like spreading of Tau pathology in the human brain.
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Affiliation(s)
- Ann-Charlotte Granholm
- Department of Neurosurgery, University of Colorado Anschutz Medical Center, Aurora, CO 80045, USA
| | - Eric D. Hamlett
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA;
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7
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Bartosch AMW, Youth EHH, Hansen S, Wu Y, Buchanan HM, Kaufman ME, Xiao H, Koo SY, Ashok A, Sivakumar S, Soni RK, Dumitrescu LC, Lam TG, Ropri AS, Lee AJ, Klein HU, Vardarajan BN, Bennett DA, Young-Pearse TL, De Jager PL, Hohman TJ, Sproul AA, Teich AF. ZCCHC17 Modulates Neuronal RNA Splicing and Supports Cognitive Resilience in Alzheimer's Disease. J Neurosci 2024; 44:e2324222023. [PMID: 38050142 PMCID: PMC10860597 DOI: 10.1523/jneurosci.2324-22.2023] [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: 12/20/2022] [Revised: 09/22/2023] [Accepted: 11/07/2023] [Indexed: 12/06/2023] Open
Abstract
ZCCHC17 is a putative master regulator of synaptic gene dysfunction in Alzheimer's disease (AD), and ZCCHC17 protein declines early in AD brain tissue, before significant gliosis or neuronal loss. Here, we investigate the function of ZCCHC17 and its role in AD pathogenesis using data from human autopsy tissue (consisting of males and females) and female human cell lines. Co-immunoprecipitation (co-IP) of ZCCHC17 followed by mass spectrometry analysis in human iPSC-derived neurons reveals that ZCCHC17's binding partners are enriched for RNA-splicing proteins. ZCCHC17 knockdown results in widespread RNA-splicing changes that significantly overlap with splicing changes found in AD brain tissue, with synaptic genes commonly affected. ZCCHC17 expression correlates with cognitive resilience in AD patients, and we uncover an APOE4-dependent negative correlation of ZCCHC17 expression with tangle burden. Furthermore, a majority of ZCCHC17 interactors also co-IP with known tau interactors, and we find a significant overlap between alternatively spliced genes in ZCCHC17 knockdown and tau overexpression neurons. These results demonstrate ZCCHC17's role in neuronal RNA processing and its interaction with pathology and cognitive resilience in AD, and suggest that the maintenance of ZCCHC17 function may be a therapeutic strategy for preserving cognitive function in the setting of AD pathology.
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Affiliation(s)
- Anne Marie W Bartosch
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Elliot H H Youth
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Shania Hansen
- Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Yiyang Wu
- Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Heather M Buchanan
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Maria E Kaufman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Harrison Xiao
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - So Yeon Koo
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Archana Ashok
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Sharanya Sivakumar
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Rajesh K Soni
- Proteomics and Macromolecular Crystallography Shared Resource, Herbert Irving Comprehensive Cancer Center, New York, New York 10032
| | - Logan C Dumitrescu
- Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Tiffany G Lam
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Ali S Ropri
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Annie J Lee
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
- Department of Neurology, Center for Translational & Computational Neuroimmunology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, New York 10032
| | - Hans-Ulrich Klein
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
- Department of Neurology, Center for Translational & Computational Neuroimmunology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, New York 10032
| | - Badri N Vardarajan
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
- Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, New York 10032
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois 60612
| | - Tracy L Young-Pearse
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts 02138
| | - Philip L De Jager
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
- Department of Neurology, Center for Translational & Computational Neuroimmunology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, New York 10032
| | - Timothy J Hohman
- Department of Neurology, Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Andrew A Sproul
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
| | - Andrew F Teich
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York 10032
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York 10032
- Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, New York 10032
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Rupert J, Monti M, Zacco E, Tartaglia G. RNA sequestration driven by amyloid formation: the alpha synuclein case. Nucleic Acids Res 2023; 51:11466-11478. [PMID: 37870427 PMCID: PMC10681735 DOI: 10.1093/nar/gkad857] [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: 04/25/2023] [Revised: 08/15/2023] [Accepted: 09/26/2023] [Indexed: 10/24/2023] Open
Abstract
Nucleic acids can act as potent modulators of protein aggregation, and RNA has the ability to either hinder or facilitate protein assembly, depending on the molecular context. In this study, we utilized a computational approach to characterize the physico-chemical properties of regions involved in amyloid aggregation. In various experimental datasets, we observed that while the core is hydrophobic and highly ordered, external regions, which are more disordered, display a distinct tendency to interact with nucleic acids. To validate our predictions, we performed aggregation assays with alpha-synuclein (aS140), a non-nucleic acid-binding amyloidogenic protein, and a mutant truncated at the acidic C-terminus (aS103), which is predicted to have a higher tendency to interact with RNA. For both aS140 and aS103, we observed an acceleration of aggregation upon RNA addition, with a significantly stronger effect for aS103. Due to favorable electrostatics, we noted an enhanced nucleic acid sequestration ability for the aggregated aS103, allowing it to entrap a larger amount of RNA compared to the aggregated wild-type counterpart. Overall, our research suggests that RNA sequestration might be a common phenomenon linked to protein aggregation, constituting a gain-of-function mechanism that warrants further investigation.
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Affiliation(s)
- Jakob Rupert
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Via Enrico Melen, 83, 16152, Genova, Italy
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Michele Monti
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Via Enrico Melen, 83, 16152, Genova, Italy
| | - Elsa Zacco
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Via Enrico Melen, 83, 16152, Genova, Italy
| | - Gian Gaetano Tartaglia
- Centre for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Via Enrico Melen, 83, 16152, Genova, Italy
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
- Catalan Institution for Research and Advanced Studies, ICREA, Passeig Lluís Companys 23, 08010, Barcelona, Spain
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9
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Schneeweis A, Pak DTS. Wherefore Art Tau? Functional importance of site-specific tau phosphorylation in diverse subcellular domains. Int J Biochem Cell Biol 2023; 164:106475. [PMID: 37778693 DOI: 10.1016/j.biocel.2023.106475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
Tau has canonically been considered as an axonal protein, but studies have observed tau localization in other subcellular domains of neurons. This relocated tau has been identified in both physiological and pathological conditions, and it is often labeled mislocalized. Furthermore, these forms of tau are referred to as "hyperphosphorylated" without specifying the phosphosites involved. On the contrary, we speculate that tau may have multiple physiological functions in various locations regulated via specific phosphorylation sites, although this picture is obscured by a lack of comprehensive phosphosite analysis. Here, we examine findings in the literature on the subcellular location of tau and potential roles tau has in those regions. We intentionally focus on the site-specific phosphorylated patterns involved in governing these properties, which are not well elucidated. To facilitate understanding of these events, we have begun establishing a comprehensive map of tau phosphorylation signatures. Such efforts may clarify tau's diverse physiological functions beyond the axon as well as promote development of novel therapeutic strategies directed against distinct tau subpopulations.
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Affiliation(s)
- Amanda Schneeweis
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Daniel T S Pak
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA.
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10
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Guzman BB, Son A, Litberg TJ, Huang Z, Dominguez D, Horowitz S. Emerging roles for G-quadruplexes in proteostasis. FEBS J 2023; 290:4614-4625. [PMID: 36017725 PMCID: PMC10071977 DOI: 10.1111/febs.16608] [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: 04/05/2022] [Revised: 07/22/2022] [Accepted: 08/25/2022] [Indexed: 11/29/2022]
Abstract
How nucleic acids interact with proteins, and how they affect protein folding, aggregation, and misfolding is a still-evolving area of research. Considerable effort is now focusing on a particular structure of RNA and DNA, G-quadruplexes, and their role in protein homeostasis and disease. In this state-of-the-art review, we track recent reports on how G-quadruplexes influence protein aggregation, proteolysis, phase separation, and protein misfolding diseases, and pose currently unanswered questions in the advance of this scientific field.
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Affiliation(s)
- Bryan B Guzman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ahyun Son
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA
| | - Theodore J Litberg
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA
| | - Zijue Huang
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA
| | - Daniel Dominguez
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Scott Horowitz
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA
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11
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McMillan PJ, Benbow SJ, Uhrich R, Saxton A, Baum M, Strovas T, Wheeler JM, Baker J, Liachko NF, Keene CD, Latimer CS, Kraemer BC. Tau-RNA complexes inhibit microtubule polymerization and drive disease-relevant conformation change. Brain 2023; 146:3206-3220. [PMID: 36732296 PMCID: PMC10393409 DOI: 10.1093/brain/awad032] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 01/09/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
Alzheimer's disease and related disorders feature neurofibrillary tangles and other neuropathological lesions composed of detergent-insoluble tau protein. In recent structural biology studies of tau proteinopathy, aggregated tau forms a distinct set of conformational variants specific to the different types of tauopathy disorders. However, the constituents driving the formation of distinct pathological tau conformations on pathway to tau-mediated neurodegeneration remain unknown. Previous work demonstrated RNA can serve as a driver of tau aggregation, and RNA associates with tau containing lesions, but tools for evaluating tau/RNA interactions remain limited. Here, we employed molecular interaction studies to measure the impact of tau/RNA binding on tau microtubule binding and aggregation. To investigate the importance of tau/RNA complexes (TRCs) in neurodegenerative disease, we raised a monoclonal antibody (TRC35) against aggregated tau/RNA complexes. We showed that native tau binds RNA with high affinity but low specificity, and tau binding to RNA competes with tau-mediated microtubule assembly functions. Tau/RNA interaction in vitro promotes the formation of higher molecular weight tau/RNA complexes, which represent an oligomeric tau species. Coexpression of tau and poly(A)45 RNA transgenes in Caenorhabditis elegans exacerbates tau-related phenotypes including neuronal dysfunction and pathological tau accumulation. TRC35 exhibits specificity for Alzheimer's disease-derived detergent-insoluble tau relative to soluble recombinant tau. Immunostaining with TRC35 labels a wide variety of pathological tau lesions in animal models of tauopathy, which are reduced in mice lacking the RNA binding protein MSUT2. TRC-positive lesions are evident in many human tauopathies including Alzheimer's disease, progressive supranuclear palsy, corticobasal degeneration and Pick's disease. We also identified ocular pharyngeal muscular dystrophy as a novel tauopathy disorder, where loss of function in the poly(A) RNA binding protein (PABPN1) causes accumulation of pathological tau in tissue from post-mortem human brain. Tau/RNA binding drives tau conformational change and aggregation inhibiting tau-mediated microtubule assembly. Our findings implicate cellular tau/RNA interactions as modulators of both normal tau function and pathological tau toxicity in tauopathy disorders and suggest feasibility for novel therapeutic approaches targeting TRCs.
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Affiliation(s)
- Pamela J McMillan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Sarah J Benbow
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Rikki Uhrich
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Aleen Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Misa Baum
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Timothy Strovas
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jeanna M Wheeler
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Jeremy Baker
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - Nicole F Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
| | - C Dirk Keene
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Caitlin S Latimer
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Brian C Kraemer
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
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12
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Holden MR, Krzesinski BJ, Weismiller HA, Shady JR, Margittai M. MAP2 caps tau fibrils and inhibits aggregation. J Biol Chem 2023; 299:104891. [PMID: 37286038 PMCID: PMC10404690 DOI: 10.1016/j.jbc.2023.104891] [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: 02/05/2023] [Revised: 05/13/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023] Open
Abstract
Fibrils of the microtubule-associated protein tau are intimately linked to the pathology of Alzheimer's disease (AD) and related neurodegenerative disorders. A current paradigm for pathology spreading in the human brain is that short tau fibrils transfer between neurons and then recruit naive tau monomers onto their tips, perpetuating the fibrillar conformation with high fidelity and speed. Although it is known that the propagation could be modulated in a cell-specific manner and thereby contribute to phenotypic diversity, there is still limited understanding of how select molecules are involved in this process. MAP2 is a neuronal protein that shares significant sequence homology with the repeat-bearing amyloid core region of tau. There is discrepancy about MAP2's involvement in pathology and its relationship with tau fibrillization. Here, we employed the entire repeat regions of 3R and 4R MAP2, to investigate their modulatory role in tau fibrillization. We find that both proteins block the spontaneous and seeded aggregation of 4R tau, with 4R MAP2 being slightly more potent. The inhibition of tau seeding is observed in vitro, in HEK293 cells, and in AD brain extracts, underscoring its broader scope. MAP2 monomers specifically bind to the end of tau fibrils, preventing recruitment of further tau and MAP2 monomers onto the fibril tip. The findings uncover a new function for MAP2 as a tau fibril cap that could play a significant role in modulating tau propagation in disease and may hold promise as a potential intrinsic protein inhibitor.
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Affiliation(s)
- Michael R Holden
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Brad J Krzesinski
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Hilary A Weismiller
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Justin R Shady
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA.
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13
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Bartosch AMW, Youth EHH, Hansen S, Kaufman ME, Xiao H, Koo SY, Ashok A, Sivakumar S, Soni RK, Dumitrescu LC, Lam TG, Ropri AS, Lee AJ, Klein HU, Vardarajan BN, Bennett DA, Young-Pearse TL, De Jager PL, Hohman TJ, Sproul AA, Teich AF. ZCCHC17 modulates neuronal RNA splicing and supports cognitive resilience in Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533654. [PMID: 36993746 PMCID: PMC10055234 DOI: 10.1101/2023.03.21.533654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
ZCCHC17 is a putative master regulator of synaptic gene dysfunction in Alzheimer's Disease (AD), and ZCCHC17 protein declines early in AD brain tissue, before significant gliosis or neuronal loss. Here, we investigate the function of ZCCHC17 and its role in AD pathogenesis. Co-immunoprecipitation of ZCCHC17 followed by mass spectrometry analysis in human iPSC-derived neurons reveals that ZCCHC17's binding partners are enriched for RNA splicing proteins. ZCCHC17 knockdown results in widespread RNA splicing changes that significantly overlap with splicing changes found in AD brain tissue, with synaptic genes commonly affected. ZCCHC17 expression correlates with cognitive resilience in AD patients, and we uncover an APOE4 dependent negative correlation of ZCCHC17 expression with tangle burden. Furthermore, a majority of ZCCHC17 interactors also co-IP with known tau interactors, and we find significant overlap between alternatively spliced genes in ZCCHC17 knockdown and tau overexpression neurons. These results demonstrate ZCCHC17's role in neuronal RNA processing and its interaction with pathology and cognitive resilience in AD, and suggest that maintenance of ZCCHC17 function may be a therapeutic strategy for preserving cognitive function in the setting of AD pathology.
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Affiliation(s)
- Anne Marie W. Bartosch
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Elliot H. H. Youth
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Shania Hansen
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Maria E. Kaufman
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Harrison Xiao
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - So Yeon Koo
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Archana Ashok
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Sharanya Sivakumar
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Rajesh K. Soni
- Proteomics and Macromolecular Crystallography Shared Resource, Herbert Irving Comprehensive Cancer Center, New York, NY 10032
| | - Logan C. Dumitrescu
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Tiffany G. Lam
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Ali S. Ropri
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Annie J. Lee
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY 10032
| | - Hans-Ulrich Klein
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY 10032
| | - Badri N. Vardarajan
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY 10032
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL 60612
| | - Tracy L. Young-Pearse
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115; Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138
| | - Philip L. De Jager
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
- Center for Translational & Computational Neuroimmunology, Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY 10032
| | - Timothy J. Hohman
- Vanderbilt Memory & Alzheimer’s Center, Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Andrew A. Sproul
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
| | - Andrew F. Teich
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032
- Department of Neurology, Columbia University Irving Medical Center, New York Presbyterian Hospital, New York, NY 10032
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14
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Masquelier E, Taxon E, Liang SP, Al Sabeh Y, Sepunaru L, Gordon MJ, Morse DE. A new electrochemical method that mimics phosphorylation of the core tau peptide K18 enables kinetic and structural analysis of intermediates and assembly. J Biol Chem 2023; 299:103011. [PMID: 36781124 PMCID: PMC10024187 DOI: 10.1016/j.jbc.2023.103011] [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: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023] Open
Abstract
Tau protein's reversible assembly and binding of microtubules in brain neurons are regulated by charge-neutralizing phosphorylation, while its hyperphosphorylation drives the irreversible formation of cytotoxic filaments associated with neurodegenerative diseases. However, the structural changes that facilitate these diverse functions are unclear. Here, we analyzed K18, a core peptide of tau, using newly developed spectroelectrochemical instrumentation that enables electroreduction as a surrogate for charge neutralization by phosphorylation, with simultaneous, real-time quantitative analyses of the resulting conformational transitions and assembly. We observed a tipping point between behaviors that paralleled the transition between tau's physiologically required, reversible folding and assembly and the irreversibility of assemblies. The resulting rapidly electroassembled structures represent the first fibrillar tangles of K18 that have been formed in vitro at room temperature without using heparin or other charge-complementary anionic partners. These methods make it possible to (i) trigger and analyze in real time the early stages of conformational transitions and assembly without the need for preformed seeds, heterogenous coacervation, or crowding; (ii) kinetically resolve and potentially isolate never-before-seen early intermediates in these processes; and (iii) develop assays for additional factors and mechanisms that can direct the trajectory of assembly from physiologically benign and reversible to potentially pathological and irreversible structures. We anticipate wide applicability of these methods to other amyloidogenic systems and beyond.
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Affiliation(s)
- Eloise Masquelier
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Materials Department, University of California, Santa Barbara, California, USA
| | - Esther Taxon
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Sheng-Ping Liang
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Yahya Al Sabeh
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
| | - Lior Sepunaru
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, USA
| | - Michael J Gordon
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Daniel E Morse
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, California, USA; Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA.
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15
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Montgomery K, Carroll EC, Thwin AC, Quddus AY, Hodges P, Southworth DR, Gestwicki JE. Chemical Features of Polyanions Modulate Tau Aggregation and Conformational States. J Am Chem Soc 2023; 145:3926-3936. [PMID: 36753572 PMCID: PMC9951223 DOI: 10.1021/jacs.2c08004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Indexed: 02/10/2023]
Abstract
The aggregation of tau into insoluble fibrils is a defining feature of neurodegenerative tauopathies. However, tau has a positive overall charge and is highly soluble; so, polyanions, such as heparin, are typically required to promote its aggregation in vitro. There are dozens of polyanions in living systems, and it is not clear which ones might promote this process. Here, we systematically measure the ability of 37 diverse, anionic biomolecules to initiate tau aggregation using either wild-type (WT) tau or the disease-associated P301S mutant. We find that polyanions from many different structural classes can promote fibril formation and that P301S tau is sensitive to a greater number of polyanions (28/37) than WT tau (21/37). We also find that some polyanions preferentially reduce the lag time of the aggregation reactions, while others enhance the elongation rate, suggesting that they act on partially distinct steps. From the resulting structure-activity relationships, the valency of the polyanion seems to be an important chemical feature such that anions with low valency tend to be weaker aggregation inducers, even at the same overall charge. Finally, the identity of the polyanion influences fibril morphology based on electron microscopy and limited proteolysis. These results provide insights into the crucial role of polyanion-tau interactions in modulating tau conformational dynamics with implications for understanding the tau aggregation landscape in a complex cellular environment.
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Affiliation(s)
- Kelly
M. Montgomery
- Department
of Pharmaceutical Chemistry, University
of California San Francisco, San Francisco, California 94158, United States
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
| | - Emma C. Carroll
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
| | - Aye C. Thwin
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
| | - Athena Y. Quddus
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
| | - Paige Hodges
- Department
of Pharmaceutical Chemistry, University
of California San Francisco, San Francisco, California 94158, United States
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
| | - Daniel R. Southworth
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
- Department
of Biochemistry and Biophysics, University
of California San Francisco, San Francisco, California 94158, United States
| | - Jason E. Gestwicki
- Department
of Pharmaceutical Chemistry, University
of California San Francisco, San Francisco, California 94158, United States
- The
Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California 94158, United States
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16
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Lester E, Van Alstyne M, McCann KL, Reddy S, Cheng LY, Kuo J, Pratt J, Parker R. Cytosolic condensates rich in polyserine define subcellular sites of tau aggregation. Proc Natl Acad Sci U S A 2023; 120:e2217759120. [PMID: 36626563 PMCID: PMC9934293 DOI: 10.1073/pnas.2217759120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/06/2022] [Indexed: 01/11/2023] Open
Abstract
Tau aggregates are a hallmark of multiple neurodegenerative diseases and can contain RNAs and RNA-binding proteins, including serine/arginine repetitive matrix protein 2 (SRRM2) and pinin (PNN). However, how these nuclear proteins mislocalize and their influence on the prion-like propagation of tau aggregates is unknown. We demonstrate that polyserine repeats in SRRM2 and PNN are necessary and sufficient for recruitment to tau aggregates. Moreover, we show tau aggregates preferentially grow in association with endogenous cytoplasmic assemblies-mitotic interchromatin granules and cytoplasmic speckles (CSs)-which contain SRRM2 and PNN. Polyserine overexpression in cells nucleates assemblies that are sites of tau aggregate growth. Further, modulating the levels of polyserine-containing proteins results in a corresponding change in tau aggregation. These findings define a specific protein motif, and cellular condensates, that promote tau aggregate propagation. As CSs form in induced pluripotent stem cell (iPSC) derived neurons under inflammatory or hyperosmolar stress, they may affect tau aggregate propagation in neurodegenerative disease.
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Affiliation(s)
- Evan Lester
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO80045
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Meaghan Van Alstyne
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
| | - Kathleen L. McCann
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
| | - Spoorthy Reddy
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Li Yi Cheng
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Jeff Kuo
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - James Pratt
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
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17
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Ingham DJ, Hillyer KM, McGuire MJ, Gamblin TC. In vitro Tau Aggregation Inducer Molecules Influence the Effects of MAPT Mutations on Aggregation Dynamics. Biochemistry 2022; 61:1243-1259. [PMID: 35731895 PMCID: PMC9260964 DOI: 10.1021/acs.biochem.2c00111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/01/2022] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) and Alzheimer's disease-related dementias (ADRDs) affect 6 million Americans, and they are projected to have an estimated health care cost of $355 billion for 2021. A histopathological hallmark of AD and many ADRDs is the aberrant intracellular accumulation of the microtubule-associated protein tau. These neurodegenerative disorders that contain tau aggregates are collectively known as tauopathies, and recent structural studies have shown that different tauopathies are characterized by different "strains" of tau filaments. In addition, mutations in the gene that encodes for tau protein expression have been associated with a group of tauopathies known as frontotemporal dementias with parkinsonism linked to chromosome 17 (FTDP-17 or familial frontotemporal dementia). In vitro studies often use small molecules to induce tau aggregation as tau is extremely soluble and does not spontaneously aggregate under typical laboratory conditions, and the use of authentic filaments to conduct in vitro studies is not feasible. This study highlights how different inducer molecules can have fundamental disparities to how disease-related mutations affect the aggregation dynamics of tau. Using three different classes of tau aggregation inducer molecules, we characterized disease-relevant mutations in tau's PGGG motifs at positions P301S, P332S, and P364S. When comparing these mutations to wild-type tau, we found that depending on the type of inducer molecule used, we saw fundamental differences in total aggregation, aggregation kinetics, immunoreactivity, and filament numbers, length, and width. These data are consistent with the possibility that different tau aggregation inducer molecules make different structural polymorphs, although this possibility would need to be confirmed by high-resolution techniques such as cryo-electron microscopy. The data also show that disease-associated missense mutations in tau impact tau aggregation differently depending on the mechanism of aggregation induction.
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Affiliation(s)
- David J. Ingham
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, 66045, United States
| | - Kelsey M. Hillyer
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, 66045, United States
| | - Madison J. McGuire
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, 66045, United States
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18
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Zwierzchowski-Zarate AN, Mendoza-Oliva A, Kashmer OM, Collazo-Lopez JE, White CL, Diamond MI. RNA induces unique tau strains and stabilizes Alzheimer's disease seeds. J Biol Chem 2022; 298:102132. [PMID: 35700826 PMCID: PMC9364032 DOI: 10.1016/j.jbc.2022.102132] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022] Open
Abstract
Tau aggregation underlies neurodegenerative tauopathies, and trans-cellular propagation of tau assemblies of unique structure, i.e. strains, may underlie the diversity of these disorders. Polyanions have been reported to induce tau aggregation in vitro, but the precise trigger to convert tau from an inert to a seed-competent form in disease states is unknown. RNA triggers tau fibril formation in vitro and has been observed to associate with neurofibrillary tangles in human brain. Here we have tested whether RNA exerts sequence-specific effects on tau assembly and strain formation. We found that three RNA homopolymers, polyA, polyU, and polyC, all bound tau, but only polyA RNA triggered seed and fibril formation. In addition, polyA:tau seeds and fibrils were sensitive to RNase. We also observed that the origin of the RNA influenced the ability of tau to adopt a structure that would form stable strains. Human RNA potently induced tau seed formation and created tau conformations that preferentially formed stable strains in a HEK293T cell model, whereas RNA from other sources, or heparin, produced strains that were not stably maintained in cultured cells. Finally, we found that soluble, but not insoluble seeds from Alzheimer's disease (AD) brain were also sensitive to RNase. We conclude that human RNA specifically induces formation of stable tau strains, and may trigger the formation of dominant pathological assemblies that propagate in AD, and possibly other tauopathies.
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Affiliation(s)
- Amy N Zwierzchowski-Zarate
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Aydé Mendoza-Oliva
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Omar M Kashmer
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Josue E Collazo-Lopez
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Charles L White
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX USA.
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19
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Annadurai N, Malina L, Malohlava J, Hajdúch M, Das V. Tau R2 and R3 are essential regions for tau aggregation, seeding and propagation. Biochimie 2022; 200:79-86. [PMID: 35623497 DOI: 10.1016/j.biochi.2022.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 05/20/2022] [Accepted: 05/20/2022] [Indexed: 12/28/2022]
Abstract
Tauopathies are characterised by intracellular deposits of fibrillar tau tangles. However, the interneuronal spread of pathological tau species precedes the development of major tau burdens. Two amyloid motifs, VQIINK in repeat 2 and VQIVYK in repeat 3, of tau repeat domain, assemble into β-sheet-rich fibrils on their own but alone do not form seed-competent fibrils. In contrast, the entire R3 region self-aggregates and forms seed-competent fibrils. Our study aimed to identify the minimal regions in the tau repeat domain that define seeding and its impact on intracellular tau phosphorylation and aggregation. Using peptides of individual repeats, we show that R2, like R3, forms seed-competent fibrils when assembled in the presence of heparin. However, R3, but not R2, forms seed-competent fibrils when assembled without heparin, even though both R2 and R3 have identical N-terminal hexapeptide and cysteine residue sequences. Moreover, cysteine to alanine substitution in R3 abrogates its self-aggregation and seeding potency. Tau RD P301S biosensor cells and Tau P301L (0N4R)-expressing HEK293 cells seeded with R2 and R3 fibrils show the induction of pathological phosphorylation of tau at Ser262/Ser396/Ser404 positions and oligomerisation of native tau. Protein fractions of biosensor cells seeded with R2 and R3 fibrils reseed endogenous tau aggregation when introduced into a fresh set of biosensor cells. Our findings suggest that R3 may be the minimal region for pathological seed generation under physiological conditions, whereas R2 might need polyanionic cofactors to generate pathogenic seeds. Lastly, R2 and R3 fibrils induce template-induced misfolding and pathological hyperphosphorylation of intracellular tau, making intracellular tau seed-competent.
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Affiliation(s)
- Narendran Annadurai
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 77900, Olomouc, Czech Republic
| | - Lukáš Malina
- Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacký University in Olomouc, Olomouc, Czech Republic
| | - Jakub Malohlava
- Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacký University in Olomouc, Olomouc, Czech Republic
| | - Marián Hajdúch
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 77900, Olomouc, Czech Republic; Czech Advanced Technologies and Research Institute (CATRIN), Institute of Molecular and Translational Medicine, Palacký University Olomouc, Krizkovskeho 511/8, 77900, Olomouc, Czech Republic
| | - Viswanath Das
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 77900, Olomouc, Czech Republic; Czech Advanced Technologies and Research Institute (CATRIN), Institute of Molecular and Translational Medicine, Palacký University Olomouc, Krizkovskeho 511/8, 77900, Olomouc, Czech Republic.
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20
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Cryo-EM structure of RNA-induced tau fibrils reveals a small C-terminal core that may nucleate fibril formation. Proc Natl Acad Sci U S A 2022; 119:e2119952119. [PMID: 35377792 PMCID: PMC9169762 DOI: 10.1073/pnas.2119952119] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In neurodegenerative diseases including Alzheimer’s and amyotrophic lateral sclerosis, proteins that bind RNA are found in aggregated forms in autopsied brains. Evidence suggests that RNA aids nucleation of these pathological aggregates; however, the mechanism has not been investigated at the level of atomic structure. Here, we present the 3.4-Å resolution structure of fibrils of full-length recombinant tau protein in the presence of RNA, determined by electron cryomicroscopy (cryo-EM). The structure reveals the familiar in-register cross-β amyloid scaffold but with a small fibril core spanning residues Glu391 to Ala426, a region disordered in the fuzzy coat in all previously studied tau polymorphs. RNA is bound on the fibril surface to the positively charged residues Arg406 and His407 and runs parallel to the fibril axis. The fibrils dissolve when RNase is added, showing that RNA is necessary for fibril integrity. While this structure cannot exist simultaneously with the tau fibril structures extracted from patients’ brains, it could conceivably account for the nucleating effects of RNA cofactors followed by remodeling as fibrils mature.
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21
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Tau mRNA Metabolism in Neurodegenerative Diseases: A Tangle Journey. Biomedicines 2022; 10:biomedicines10020241. [PMID: 35203451 PMCID: PMC8869323 DOI: 10.3390/biomedicines10020241] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/07/2022] Open
Abstract
Tau proteins are known to be mainly involved in regulation of microtubule dynamics. Besides this function, which is critical for axonal transport and signal transduction, tau proteins also have other roles in neurons. Moreover, tau proteins are turned into aggregates and consequently trigger many neurodegenerative diseases termed tauopathies, of which Alzheimer’s disease (AD) is the figurehead. Such pathological aggregation processes are critical for the onset of these diseases. Among the various causes of tau protein pathogenicity, abnormal tau mRNA metabolism, expression and dysregulation of tau post-translational modifications are critical steps. Moreover, the relevance of tau function to general mRNA metabolism has been highlighted recently in tauopathies. In this review, we mainly focus on how mRNA metabolism impacts the onset and development of tauopathies. Thus, we intend to portray how mRNA metabolism of, or mediated by, tau is associated with neurodegenerative diseases.
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22
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Limorenko G, Lashuel HA. Revisiting the grammar of Tau aggregation and pathology formation: how new insights from brain pathology are shaping how we study and target Tauopathies. Chem Soc Rev 2021; 51:513-565. [PMID: 34889934 DOI: 10.1039/d1cs00127b] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Converging evidence continues to point towards Tau aggregation and pathology formation as central events in the pathogenesis of Alzheimer's disease and other Tauopathies. Despite significant advances in understanding the morphological and structural properties of Tau fibrils, many fundamental questions remain about what causes Tau to aggregate in the first place. The exact roles of cofactors, Tau post-translational modifications, and Tau interactome in regulating Tau aggregation, pathology formation, and toxicity remain unknown. Recent studies have put the spotlight on the wide gap between the complexity of Tau structures, aggregation, and pathology formation in the brain and the simplicity of experimental approaches used for modeling these processes in research laboratories. Embracing and deconstructing this complexity is an essential first step to understanding the role of Tau in health and disease. To help deconstruct this complexity and understand its implication for the development of effective Tau targeting diagnostics and therapies, we firstly review how our understanding of Tau aggregation and pathology formation has evolved over the past few decades. Secondly, we present an analysis of new findings and insights from recent studies illustrating the biochemical, structural, and functional heterogeneity of Tau aggregates. Thirdly, we discuss the importance of adopting new experimental approaches that embrace the complexity of Tau aggregation and pathology as an important first step towards developing mechanism- and structure-based therapies that account for the pathological and clinical heterogeneity of Alzheimer's disease and Tauopathies. We believe that this is essential to develop effective diagnostics and therapies to treat these devastating diseases.
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Affiliation(s)
- Galina Limorenko
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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Limorenko G, Lashuel HA. To target Tau pathologies, we must embrace and reconstruct their complexities. Neurobiol Dis 2021; 161:105536. [PMID: 34718129 DOI: 10.1016/j.nbd.2021.105536] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 10/20/2022] Open
Abstract
The accumulation of hyperphosphorylated fibrillar Tau aggregates in the brain is one of the defining hallmarks of Tauopathy diseases, including Alzheimer's disease. However, the primary events or molecules responsible for initiation of the pathological Tau aggregation and spreading remain unknown. The discovery of heparin as an effective inducer of Tau aggregation in vitro was instrumental to enabling different lines of research into the role of Tau aggregation in the pathogenesis of Tauopathies. However, recent proteomics and cryogenic electron microscopy (cryo-EM) studies have revealed that heparin-induced Tau fibrils generated in vitro do not reproduce the biochemical and ultrastructural properties of disease-associated brain-derived Tau fibrils. These observations demand that we reassess our current approaches for investigating the mechanisms underpinning Tau aggregation and pathology formation. Our review article presents an up-to-date survey and analyses of 1) the evolution of our understanding of the interactions between Tau and heparin, 2) the various structural and mechanistic models of the heparin-induced Tau aggregation, 3) the similarities and differences between brain-derived and heparin-induced Tau fibrils; and 4) emerging concepts on the biochemical and structural determinants underpinning Tau pathological heterogeneity in Tauopathies. Our analyses identify specific knowledge gaps and call for 1) embracing the complexities of Tau pathologies; 2) reassessment of current approaches to investigate, model and reproduce pathological Tau aggregation as it occurs in the brain; 3) more research towards a better understanding of the naturally-occurring cofactor molecules that are associated with Tau brain pathology initiation and propagation; and 4) developing improved approaches for in vitro production of the Tau aggregates and fibrils that recapitulate and/or amplify the biochemical and structural complexity and diversity of pathological Tau in Tauopathies. This will result in better and more relevant tools, assays, and mechanistic models, which could significantly improve translational research and the development of drugs and antibodies that have higher chances for success in the clinic.
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Affiliation(s)
- Galina Limorenko
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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Dong X, Qi R, Qiao Q, Li X, Li F, Wan J, Zhang Q, Wei G. Heparin remodels the microtubule-binding repeat R3 of Tau protein towards fibril-prone conformations. Phys Chem Chem Phys 2021; 23:20406-20418. [PMID: 34494046 DOI: 10.1039/d1cp02651h] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Abnormal aggregation of proteins into pathological amyloid fibrils is implicated in a wide range of devastating human neurodegenerative diseases. Intracellular fibrillary inclusions formed by Tau protein are characterized as the hallmark of tauopathies, including Alzheimer's disease and frontotemporal dementia. Heparin has been often used to trigger Tau aggregation in in vitro studies. However, the conformational changes induced by heparin and the underlying mechanism of promotion of Tau aggregation by heparin are not well understood. Structural characterization of Tau oligomers in the early stage of fibrillation is of great importance but remains challenging due to their dynamic and heterogeneous nature. R3, the third microtubule-binding repeat of Tau, contains the fibril-nucleating core (PHF6) and is crucial for Tau aggregation. In this study, utilizing extensive all-atom replica-exchange molecular dynamic simulations, we explored the conformational ensembles of R3 monomer/dimer in the absence and presence of heparin. Our results show that without heparin, both monomeric and dimeric R3 preferentially adopt collapsed β-sheet-containing conformations and PHF6 plays an important role in the formation of interchain β-sheet structures, while in the presence of heparin, R3 can populate relatively extended disordered states where chain dimension is similar to that of R3 in Tau filaments. Through electrostatic, hydrogen-bonding and hydrophobic interactions, heparin has a preference for interacting with residues V306/Q307/K317/K321/H329/H330/K331 which distribute throughout the entire sequence of R3, in turn acting as a template to extend R3 conformations. More importantly, heparin alters intramolecular/intermolecular interaction patterns of R3 and increases the intermolecular contact regions. Our results suggest that heparin remodels the conformations of R3 towards fibril-prone structures by increasing chain dimension and intermolecular contact regions, which may shed light on the atomic mechanism of heparin-induced amyloid fibrillization of Tau protein.
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Affiliation(s)
- Xuewei Dong
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China.
| | - Ruxi Qi
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| | - Qin Qiao
- Digital Medical Research Center, School of Basic Medical Sciences, Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, Fudan University, Shanghai 200032, People's Republic of China
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Fangying Li
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China.
| | - Jiaqian Wan
- College of Physical Education and Training, Shanghai University of Sport, Shanghai 200438, People's Republic of China
| | - Qingwen Zhang
- College of Physical Education and Training, Shanghai University of Sport, Shanghai 200438, People's Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China.
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25
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Weismiller HA, Holub TJ, Krzesinski BJ, Margittai M. A thiol-based intramolecular redox switch in four-repeat tau controls fibril assembly and disassembly. J Biol Chem 2021; 297:101021. [PMID: 34339733 PMCID: PMC8387771 DOI: 10.1016/j.jbc.2021.101021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/17/2021] [Accepted: 07/28/2021] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress has been implicated in the pathogenesis and progression of several tauopathies, including Alzheimer's disease. The deposition of fibrillar inclusions made of tau protein is one of the pathological hallmarks of these disorders. Although it is becoming increasingly evident that the specific fibril structure may vary from one tauopathy to another and it is recognized that different types of isoforms (three-repeat and four-repeat tau) can be selectively deposited, little is known about the role oxidation may play in aggregation. Four-repeat tau contains two cysteines that can form an intramolecular disulfide bond, resulting in a structurally restrained compact monomer. There is discrepancy as to whether this monomer can aggregate or not. Using isolated four-repeat tau monomers (htau40) with intramolecular disulfide bonds, we demonstrate that these proteins form fibrils. The fibrils are less stable than fibrils formed under reducing conditions but are highly effective in seeding oxidized tau monomers. Conversely, a strong seeding barrier prevents incorporation of reduced tau monomers, tau mimics in which the cysteines have been replaced by alanines or serines, and three-repeat tau (htau23), a single-cysteine isoform. The barrier also holds true when seed and monomer types are reversed, indicating that oxidized and reduced tau are incompatible with each other. Surprisingly, fibrils composed of compact tau disaggregate upon reduction, highlighting the importance of the intramolecular disulfide bond for fibril stability. The findings uncover a novel binary redox switch that controls the aggregation and disaggregation of these fibrils and extend the conformational spectrum of tau aggregates.
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Affiliation(s)
- Hilary A Weismiller
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Tyler J Holub
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Brad J Krzesinski
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA
| | - Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado, USA.
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26
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Abstract
Pathogenesis of tauopathies involves conversion of tau monomer into pathological tau conformers that serve as templates to recruit native tau into growing assemblies. Small soluble tau seeds have been proposed to drive pathological tau assembly in vitro, in cells and in vivo. We have previously described the isolation of monomeric pathogenic tau seeds derived from recombinant samples and tauopathy tissues but in-depth biophysical characterization of these species has not been done. Here we describe a chromatographic method to isolate recombinant soluble tau seeds derived from heparin treatment. We used biochemical and biophysical approaches to show that the seeds are predominantly monomeric and have the capacity to nucleate aggregation of inert forms of tau in vitro and in cells. Finally, we used crosslinking mass spectrometry to identify the topological changes in tau as it converts from an inert state to a pathogenic seed. Future studies will reveal the relationship between soluble seeds and structural polymorphs derived from tauopathies to help diagnose and develop therapeutics targeting specific tauopathies.
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Affiliation(s)
- Zhiqiang Hou
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Dailu Chen
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Bryan D Ryder
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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27
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McMillan PJ, Strovas TJ, Baum M, Mitchell BK, Eck RJ, Hendricks N, Wheeler JM, Latimer CS, Keene CD, Kraemer BC. Pathological tau drives ectopic nuclear speckle scaffold protein SRRM2 accumulation in neuron cytoplasm in Alzheimer's disease. Acta Neuropathol Commun 2021; 9:117. [PMID: 34187600 PMCID: PMC8243890 DOI: 10.1186/s40478-021-01219-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 01/19/2023] Open
Abstract
Several conserved nuclear RNA binding proteins (sut-1, sut-2, and parn-2) control tau aggregation and toxicity in C. elegans, mice, and human cells. MSUT2 protein normally resides in nuclear speckles, membraneless organelles composed of phase-separated RNAs and RNA-binding proteins that mediate critical steps in mRNA processing including mRNA splicing. We used human pathological tissue and transgenic mice to identify Alzheimer’s disease-specific cellular changes related to nuclear speckles. We observed that nuclear speckle constituent scaffold protein SRRM2 is mislocalized and accumulates in cytoplasmic lesions in AD brain tissue. Furthermore, progression of tauopathy in transgenic mice is accompanied by increasing mislocalization of SRRM2 from the neuronal nucleus to the soma. In AD brain tissue, SRRM2 mislocalization associates with increased severity of pathological tau deposition. These findings suggest potential mechanisms by which pathological tau impacts nuclear speckle function in diverse organisms ranging from C. elegans to mice to humans. Future translational studies aimed at restoring nuclear speckle homeostasis may provide novel candidate therapeutic targets for pharmacological intervention.
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28
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Cantrelle FX, Loyens A, Trivelli X, Reimann O, Despres C, Gandhi NS, Hackenberger CPR, Landrieu I, Smet-Nocca C. Phosphorylation and O-GlcNAcylation of the PHF-1 Epitope of Tau Protein Induce Local Conformational Changes of the C-Terminus and Modulate Tau Self-Assembly Into Fibrillar Aggregates. Front Mol Neurosci 2021; 14:661368. [PMID: 34220449 PMCID: PMC8249575 DOI: 10.3389/fnmol.2021.661368] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
Phosphorylation of the neuronal microtubule-associated Tau protein plays a critical role in the aggregation process leading to the formation of insoluble intraneuronal fibrils within Alzheimer's disease (AD) brains. In recent years, other posttranslational modifications (PTMs) have been highlighted in the regulation of Tau (dys)functions. Among these PTMs, the O-β-linked N-acetylglucosaminylation (O-GlcNAcylation) modulates Tau phosphorylation and aggregation. We here focus on the role of the PHF-1 phospho-epitope of Tau C-terminal domain that is hyperphosphorylated in AD (at pS396/pS404) and encompasses S400 as the major O-GlcNAc site of Tau while two additional O-GlcNAc sites were found in the extreme C-terminus at S412 and S413. Using high resolution NMR spectroscopy, we showed that the O-GlcNAc glycosylation reduces phosphorylation of PHF-1 epitope by GSK3β alone or after priming by CDK2/cyclin A. Furthermore, investigations of the impact of PTMs on local conformation performed in small peptides highlight the role of S404 phosphorylation in inducing helical propensity in the region downstream pS404 that is exacerbated by other phosphorylations of PHF-1 epitope at S396 and S400, or O-GlcNAcylation of S400. Finally, the role of phosphorylation and O-GlcNAcylation of PHF-1 epitope was probed in in-vitro fibrillization assays in which O-GlcNAcylation slows down the rate of fibrillar assembly while GSK3β phosphorylation stimulates aggregation counteracting the effect of glycosylation.
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Affiliation(s)
- François-Xavier Cantrelle
- Risk Factors and Molecular Determinants of Aging-Related Diseases, U1167, Institut Pasteur de Lille, CHU Lille, INSERM, University of Lille, Lille, France.,CNRS, ERL9002 - Integrative Structural Biology, Lille, France
| | - Anne Loyens
- Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, U1172, CHU Lille, INSERM, University of Lille, Lille, France
| | - Xavier Trivelli
- Université de Lille, CNRS, INRAE, Centrale Lille, Université d'Artois, Lille, France
| | - Oliver Reimann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany.,Institut für Chemie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Clément Despres
- Risk Factors and Molecular Determinants of Aging-Related Diseases, U1167, Institut Pasteur de Lille, CHU Lille, INSERM, University of Lille, Lille, France
| | - Neha S Gandhi
- Centre for Genomics and Personalised Health, Cancer and Ageing Research Program, School of Chemistry and Physics, Faculty of Science and Engineering, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Christian P R Hackenberger
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany.,Institut für Chemie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Isabelle Landrieu
- Risk Factors and Molecular Determinants of Aging-Related Diseases, U1167, Institut Pasteur de Lille, CHU Lille, INSERM, University of Lille, Lille, France.,CNRS, ERL9002 - Integrative Structural Biology, Lille, France
| | - Caroline Smet-Nocca
- Risk Factors and Molecular Determinants of Aging-Related Diseases, U1167, Institut Pasteur de Lille, CHU Lille, INSERM, University of Lille, Lille, France.,CNRS, ERL9002 - Integrative Structural Biology, Lille, France
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Abstract
Protein aggregates can sequester RNA in neurodegenerative disease, but the exact RNAs sequestered by tau inclusions have remained uncharacterized. In this issue of Neuron, Lester et al. (2021) begin to identify these RNAs and reveal related perturbations in nuclear speckles.
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Lester E, Ooi FK, Bakkar N, Ayers J, Woerman AL, Wheeler J, Bowser R, Carlson GA, Prusiner SB, Parker R. Tau aggregates are RNA-protein assemblies that mislocalize multiple nuclear speckle components. Neuron 2021; 109:1675-1691.e9. [PMID: 33848474 PMCID: PMC8141031 DOI: 10.1016/j.neuron.2021.03.026] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/05/2021] [Accepted: 03/18/2021] [Indexed: 12/13/2022]
Abstract
Tau aggregates contribute to neurodegenerative diseases, including frontotemporal dementia and Alzheimer's disease (AD). Although RNA promotes tau aggregation in vitro, whether tau aggregates in cells contain RNA is unknown. We demonstrate, in cell culture and mouse brains, that cytosolic and nuclear tau aggregates contain RNA with enrichment for small nuclear RNAs (snRNAs) and small nucleolar RNAs (snoRNAs). Nuclear tau aggregates colocalize with and alter the composition, dynamics, and organization of nuclear speckles, membraneless organelles involved in pre-mRNA splicing. Moreover, several nuclear speckle components, including SRRM2, mislocalize to cytosolic tau aggregates in cells, mouse brains, and brains of individuals with AD, frontotemporal dementia (FTD), and corticobasal degeneration (CBD). Consistent with these alterations, we observe that the presence of tau aggregates is sufficient to alter pre-mRNA splicing. This work identifies tau alteration of nuclear speckles as a feature of tau aggregation that may contribute to the pathology of tau aggregates.
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Affiliation(s)
- Evan Lester
- Department of Biochemistry, University of Colorado, Boulder, CO, USA; Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Felicia K Ooi
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Nadine Bakkar
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - Jacob Ayers
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA; Department of Neurology, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Amanda L Woerman
- Department of Biology and Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, USA
| | - Joshua Wheeler
- Department of Biochemistry, University of Colorado, Boulder, CO, USA; Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pathology, Stanford University, Stanford, CA, USA
| | - Robert Bowser
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, USA
| | - George A Carlson
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA; Department of Neurology, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA; Department of Neurology, Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA, USA; Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO, USA; Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA.
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31
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Retromer dysfunction at the nexus of tauopathies. Cell Death Differ 2021; 28:884-899. [PMID: 33473181 PMCID: PMC7937680 DOI: 10.1038/s41418-020-00727-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/13/2020] [Accepted: 12/27/2020] [Indexed: 01/30/2023] Open
Abstract
Tauopathies define a broad range of neurodegenerative diseases that encompass pathological aggregation of the microtubule-associated protein tau. Although tau aggregation is a central feature of these diseases, their underlying pathobiology is remarkably heterogeneous at the molecular level. In this review, we summarize critical differences that account for this heterogeneity and contrast the physiological and pathological functions of tau. We focus on the recent understanding of its prion-like behavior that accounts for its spread in the brain. Moreover, we acknowledge the limited appreciation about how upstream cellular changes influence tauopathy. Dysfunction of the highly conserved endosomal trafficking complex retromer is found in numerous tauopathies such as Alzheimer's disease, Pick's disease, and progressive supranuclear palsy, and we discuss how this has emerged as a major contributor to various aspects of neurodegenerative diseases. In particular, we highlight recent investigations that have elucidated the contribution of retromer dysfunction to distinct measures of tauopathy such as tau hyperphosphorylation, aggregation, and impaired cognition and behavior. Finally, we discuss the potential benefit of targeting retromer for modifying disease burden and identify important considerations with such an approach moving toward clinical translation.
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32
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Devitt G, Crisford A, Rice W, Weismiller HA, Fan Z, Commins C, Hyman BT, Margittai M, Mahajan S, Mudher A. Conformational fingerprinting of tau variants and strains by Raman spectroscopy. RSC Adv 2021; 11:8899-8915. [PMID: 34381596 PMCID: PMC8330415 DOI: 10.1039/d1ra00870f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 02/18/2021] [Indexed: 12/11/2022] Open
Abstract
Tauopathies are a group of disorders in which the deposition of abnormally folded tau protein accompanies neurodegeneration. The development of methods for detection and classification of pathological changes in protein conformation are desirable for understanding the factors that influence the structural polymorphism of aggregates in tauopathies. We have previously demonstrated the utility of Raman spectroscopy for the characterization and discrimination of different protein aggregates, including tau, based on their unique conformational signatures. Building on this, in the present study, we assess the utility of Raman spectroscopy for characterizing and distinguishing different conformers of the same protein which in the case of tau are unique tau strains generated in vitro. We now investigate the impact of aggregation environment, cofactors, post-translational modification and primary sequence on the Raman fingerprint of tau fibrils. Using quantitative conformational fingerprinting and multivariate statistical analysis, we found that the aggregation of tau in different buffer conditions resulted in the formation of distinct fibril strains. Unique spectral markers were identified for tau fibrils generated using heparin or RNA cofactors, as well as for phosphorylated tau. We also determined that the primary sequence of the tau monomer influenced the conformational signature of the resulting tau fibril, including 2N4R, 0N3R, K18 and P301S tau variants. These results highlight the conformational polymorphism of tau fibrils, which is reflected in the wide range of associated neurological disorders. Furthermore, the analyses presented in this study provide a benchmark for the Raman spectroscopic characterization of tau strains, which may shed light on how the aggregation environment, cofactors and post-translational modifications influence tau conformation in vivo in future studies.
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Affiliation(s)
- George Devitt
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK.,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Anna Crisford
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - William Rice
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Hilary A Weismiller
- Department of Chemistry and Biochemistry, University of Denver 2190 E. Iliff Ave. Denver CO 80208 USA
| | - Zhanyun Fan
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Caitlin Commins
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Bradley T Hyman
- Department of Neurology, Harvard Medical School, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital Charlestown MA 02129 USA
| | - Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver 2190 E. Iliff Ave. Denver CO 80208 USA
| | - Sumeet Mahajan
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton Highfield Southampton SO17 1BJ UK.,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
| | - Amrit Mudher
- School of Biological Sciences, Faculty of Environmental and Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK .,Institute for Life Sciences, University of Southampton Highfield Southampton SO17 1BJ UK
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Tau PTM Profiles Identify Patient Heterogeneity and Stages of Alzheimer's Disease. Cell 2020; 183:1699-1713.e13. [PMID: 33188775 DOI: 10.1016/j.cell.2020.10.029] [Citation(s) in RCA: 347] [Impact Index Per Article: 86.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 08/27/2020] [Accepted: 10/16/2020] [Indexed: 01/06/2023]
Abstract
To elucidate the role of Tau isoforms and post-translational modification (PTM) stoichiometry in Alzheimer's disease (AD), we generated a high-resolution quantitative proteomics map of 95 PTMs on multiple isoforms of Tau isolated from postmortem human tissue from 49 AD and 42 control subjects. Although Tau PTM maps reveal heterogeneity across subjects, a subset of PTMs display high occupancy and frequency for AD, suggesting importance in disease. Unsupervised analyses indicate that PTMs occur in an ordered manner, leading to Tau aggregation. The processive addition and minimal set of PTMs associated with seeding activity was further defined by analysis of size-fractionated Tau. To summarize, features in the Tau protein critical for disease intervention at different stages of disease are identified, including enrichment of 0N and 4R isoforms, underrepresentation of the C terminus, an increase in negative charge in the proline-rich region (PRR), and a decrease in positive charge in the microtubule binding domain (MBD).
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Heo CE, Han JY, Lim S, Lee J, Im D, Lee MJ, Kim YK, Kim HI. ATP Kinetically Modulates Pathogenic Tau Fibrillations. ACS Chem Neurosci 2020; 11:3144-3152. [PMID: 32915536 DOI: 10.1021/acschemneuro.0c00479] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Advanced understanding of Alzheimer's disease (AD) and several tauopathies over the past decades indicates the pathological importance of tau aggregation in these diseases. Herein, we demonstrated that adenosine triphosphate (ATP), a highly charged anionic molecule found abundantly in the cytosol of cells, catalyzes fibrillation of tau as well as human islet amyloid polypeptide, a representative of basic intrinsically disordered proteins. Our results showed that ATP attracts multiple lysine residues of the four-repeat domain of tau (K18) via supramolecular complexation, thereby forming dimers that are converted to nuclei and accelerate fibril elongation. However, ATP was not directly incorporated into the K18 fibrils, suggesting that ATP plays the role of a catalyst, rather than a reactant, during K18 fibrillation. We also characterized the correlation between ATP dyshomeostasis and tau aggregation in the cellular environment. Our multiple biophysical approaches, including native mass spectrometry (MS), small-angle X-ray scattering (SAXS), and molecular dynamics (MD) simulation, provided insights into the molecular-level influence of ATP on the structural changes and fibrillation of tau.
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Affiliation(s)
- Chae Eun Heo
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
- Center for Proteogenomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Jong Yoon Han
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
- Center for Proteogenomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Sungsu Lim
- Brain Science Institute, Center for Neuromedicine, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Jeeyoung Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Dongjoon Im
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
- Center for Proteogenomics Research, Korea University, Seoul 02841, Republic of Korea
| | - Min Jae Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Yun Kyung Kim
- Brain Science Institute, Center for Neuromedicine, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
- Department of Biological Chemistry, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Hugh I. Kim
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea
- Center for Proteogenomics Research, Korea University, Seoul 02841, Republic of Korea
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Majewski J, Jones EM, Vander Zanden CM, Biernat J, Mandelkow E, Chi EY. Lipid membrane templated misfolding and self-assembly of intrinsically disordered tau protein. Sci Rep 2020; 10:13324. [PMID: 32770092 PMCID: PMC7414892 DOI: 10.1038/s41598-020-70208-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/21/2020] [Indexed: 01/21/2023] Open
Abstract
The aggregation of the intrinsically disordered tau protein into highly ordered β-sheet-rich fibrils is implicated in the pathogenesis of a range of neurodegenerative disorders. The mechanism of tau fibrillogenesis remains unresolved, particularly early events that trigger the misfolding and assembly of the otherwise soluble and stable tau. We investigated the role the lipid membrane plays in modulating the aggregation of three tau variants, the largest isoform hTau40, the truncated construct K18, and a hyperphosphorylation-mimicking mutant hTau40/3Epi. Despite being charged and soluble, the tau proteins were also highly surface active and favorably interacted with anionic lipid monolayers at the air/water interface. Membrane binding of tau also led to the formation of a macroscopic, gelatinous layer at the air/water interface, possibly related to tau phase separation. At the molecular level, tau assembled into oligomers composed of ~ 40 proteins misfolded in a β-sheet conformation at the membrane surface, as detected by in situ synchrotron grazing-incidence X-ray diffraction. Concomitantly, membrane morphology and lipid packing became disrupted. Our findings support a general tau aggregation mechanism wherein tau’s inherent surface activity and favorable interactions with anionic lipids drive tau-membrane association, inducing misfolding and self-assembly of the disordered tau into β-sheet-rich oligomers that subsequently seed fibrillation and deposition into diseased tissues.
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Affiliation(s)
- Jaroslaw Majewski
- Division of Molecular and Cellular Biology, National Science Foundation, Alexandria, VA, 22314, USA.,Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA.,Theoretical Biology and Biophysics Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Emmalee M Jones
- Nanoscience and Microsystems Engineering Graduate Program, University of New Mexico, Albuquerque, NM, 87131, USA.,Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Crystal M Vander Zanden
- Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA.,Department of Chemistry and Biochemistry, University of Colorado at Colorado Springs, Colorado Springs, CO, 80918, USA
| | - Jacek Biernat
- Center for Neurodegenerative Diseases (DZNE), 53127, Bonn, Germany.,CAESAR Research Center, 53175, Bonn, Germany
| | - Eckhard Mandelkow
- Center for Neurodegenerative Diseases (DZNE), 53127, Bonn, Germany.,CAESAR Research Center, 53175, Bonn, Germany
| | - Eva Y Chi
- Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA.
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Abstract
Many proteins, particularly those that are intrinsically disordered and carry charges have a tendency to undergo liquid liquid phase separation (LLPS). Phase separation is a widespread mechanism by which cells concentrate a set of proteins to perform molecular reactions, and appear to compartmentalize molecular functions. Among the intrinsically disordered proteins are a subset that tend to form solid inclusions in cells and contribute to the pathology of several neurodegenerative diseases. Among this subset is the tau protein, a critically important inclusion in a class of conditions known as the tauopathies, which include Alzheimer's disease. Tau in neurons strongly and selectively associates with RNA species, most notably tRNA with a nanomolar dissociation constant. Furthermore, tau and RNA, under charge matching conditions, undergo LLPS in a process known as complex coacervation. Tau-RNA LLPS is reversible, and can persist for more than 15 h without subsequent fibrilization, although after longer time periods β-sheet content can be detected by thioflavin T. These findings suggest that LLPS tau droplets or condensates can be placed on a pathway to fibrillization and be arrested by solidification or dissolve into a soluble state, depending on the condition at hand, suggesting a regulatory and physiological role for the phase separated state of tau.
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Banerjee S, Ferdosh S, Ghosh AN, Barat C. Tau protein- induced sequestration of the eukaryotic ribosome: Implications in neurodegenerative disease. Sci Rep 2020; 10:5225. [PMID: 32251304 PMCID: PMC7090008 DOI: 10.1038/s41598-020-61777-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/28/2020] [Indexed: 12/15/2022] Open
Abstract
The human tau is a microtubule-associated intrinsically unstructured protein that forms intraneuronal cytotoxic deposits in neurodegenerative diseases, like tauopathies. Recent studies indicate that in Alzheimer's disease, ribosomal dysfunction might be a crucial event in the disease pathology. Our earlier studies had demonstrated that amorphous protein aggregation in the presence of ribosome can lead to sequestration of the ribosomal components. The present study aims at determining the effect of incubation of the full-length tau protein (Ht40) and its microtubule binding 4-repeat domain (K18) on the eukaryotic ribosome. Our in vitro studies show that incubation of Ht40 and the K18 tau variants with isolated non-translating yeast ribosome can induce a loss of ribosome physical integrity resulting in formation of tau-rRNA-ribosomal protein aggregates. Incubation with the tau protein variants also led to a disappearance of the peak indicating the ribosome profile of the HeLa cell lysate and suppression of translation in the human in vitro translation system. The incubation of tau protein with the ribosomal RNA leads to the formation of tau-rRNA aggregates. The effect of K18 on the yeast ribosome can be mitigated in the presence of cellular polyanions like heparin and tRNA, thereby indicating the electrostatic nature of the aggregation process.
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Affiliation(s)
- Senjuti Banerjee
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Sehnaz Ferdosh
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India
| | - Amar Nath Ghosh
- National Institute of Cholera and Enteric Diseases P-33, C.I.T. Road, Scheme XM, Beleghata, India
| | - Chandana Barat
- Department of Biotechnology, St. Xavier's College, Park Street, Kolkata, 700016, West Bengal, India.
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39
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Gallardo R, Ranson NA, Radford SE. Amyloid structures: much more than just a cross-β fold. Curr Opin Struct Biol 2020; 60:7-16. [PMID: 31683043 DOI: 10.1016/j.sbi.2019.09.001] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/04/2019] [Indexed: 01/10/2023]
Abstract
In recent years our understanding of amyloid structure has been revolutionised by innovations in cryo-electron microscopy, electron diffraction and solid-state NMR. These techniques have yielded high-resolution structures of fibrils isolated from patients with neurodegenerative disease, as well as those formed from amyloidogenic proteins in vitro. The results not only show the expected cross-β amyloid structure, but also reveal that the amyloid fold is unexpectedly diverse and complex. Here, we discuss this diversity, highlighting dynamic regions, ligand binding motifs, cavities, non-protein components, and structural polymorphism. Collectively, these variations combine to allow the generic amyloid fold to be realised in three dimensions in different ways, and this diversity may be related to the roles of fibrils in disease.
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Affiliation(s)
- Rodrigo Gallardo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK.
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK.
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40
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From the prion-like propagation hypothesis to therapeutic strategies of anti-tau immunotherapy. Acta Neuropathol 2020; 139:3-25. [PMID: 31686182 PMCID: PMC6942016 DOI: 10.1007/s00401-019-02087-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 12/15/2022]
Abstract
The term “propagon” is used to define proteins that may transmit misfolding in vitro, in tissues or in organisms. Among propagons, misfolded tau is thought to be involved in the pathogenic mechanisms of various “tauopathies” that include Alzheimer's disease, progressive supranuclear palsy, and argyrophilic grain disease. Here, we review the available data in the literature and point out how the prion-like tau propagation has been extended from Alzheimer's disease to tauopathies. First, in Alzheimer’s disease, the progression of tau aggregation follows stereotypical anatomical stages which may be considered as spreading. The mechanisms of the propagation are now subject to intensive and controversial research. It has been shown that tau may be secreted in the interstitial fluid in an active manner as reflected by high and constant concentration of extracellular tau during Alzheimer’s pathology. Animal and cell models have been devised to mimic tau seeding and propagation, and despite their limitations, they have further supported to the prion-like propagation hypothesis. Finally, such new ways of thinking have led to different therapeutic strategies in anti-tau immunotherapy among tauopathies and have stimulated new clinical trials. However, it appears that the prion-like propagation hypothesis mainly relies on data obtained in Alzheimer’s disease. From this review, it appears that further studies are needed (1) to characterize extracellular tau species, (2) to find the right pathological tau species to target, (3) to follow in vivo tau pathology by brain imaging and biomarkers and (4) to interpret current clinical trial results aimed at reducing the progression of these pathologies. Such inputs will be essential to have a comprehensive view of these promising therapeutic strategies in tauopathies.
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41
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Fichou Y, Oberholtzer ZR, Ngo H, Cheng CY, Keller TJ, Eschmann NA, Han S. Tau-Cofactor Complexes as Building Blocks of Tau Fibrils. Front Neurosci 2019; 13:1339. [PMID: 31920504 PMCID: PMC6923735 DOI: 10.3389/fnins.2019.01339] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/27/2019] [Indexed: 12/30/2022] Open
Abstract
The aggregation of the human tau protein into neurofibrillary tangles is directly diagnostic of many neurodegenerative conditions termed tauopathies. The species, factors and events that are responsible for the initiation and propagation of tau aggregation are not clearly established, even in a simplified and artificial in vitro system. This motivates the mechanistic study of in vitro aggregation of recombinant tau from soluble to fibrillar forms, for which polyanionic cofactors are the most commonly used external inducer. In this study, we performed biophysical characterizations to unravel the mechanisms by which cofactors induce fibrillization. We first reinforce the idea that cofactors are the limiting factor to generate ThT-active tau fibrils, and establish that they act as templating reactant that trigger tau conformational rearrangement. We show that heparin has superior potency for recruiting monomeric tau into aggregation-competent species compared to any constituent intermediate or aggregate "seeds." We show that tau and cofactors form intermediate complexes whose evolution toward ThT-active fibrils is tightly regulated by tau-cofactor interactions. Remarkably, it is possible to find mild cofactors that complex with tau without forming ThT-active species, except when an external catalyst (e.g., a seed) is provided to overcome the energy barrier. In a cellular context, we propose the idea that tau could associate with cofactors to form a metastable complex that remains "inert" and reversible, until encountering a relevant seed that can trigger an irreversible transition to β-sheet containing species.
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Affiliation(s)
- Yann Fichou
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Zachary R. Oberholtzer
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Hoang Ngo
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Chi-Yuan Cheng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Timothy J. Keller
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Neil A. Eschmann
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA, United States
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42
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Litberg TJ, Docter B, Hughes MP, Bourne J, Horowitz S. DNA Facilitates Oligomerization and Prevents Aggregation via DNA Networks. Biophys J 2019; 118:162-171. [PMID: 31839258 DOI: 10.1016/j.bpj.2019.11.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/11/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022] Open
Abstract
Previous studies have shown that nucleic acids can nucleate protein aggregation in disease-related proteins, but in other cases, they can act as molecular chaperones that prevent protein aggregation, even under extreme conditions. In this study, we describe the link between these two behaviors through a combination of electron microscopy and aggregation kinetics. We find that two different proteins become soluble under harsh conditions through oligomerization with DNA. These DNA/protein oligomers form "networks," which increase the speed of oligomerization. The cases of DNA both increasing and preventing protein aggregation are observed to stem from this enhanced oligomerization. This observation raises interesting questions about the role of nucleic acids in aggregate formation in disease states.
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Affiliation(s)
- Theodore J Litberg
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado
| | - Brianne Docter
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Michael P Hughes
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California; Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California; Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, California; Department of Energy, University of California, Los Angeles, Los Angeles, California; Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California
| | - Jennifer Bourne
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Scott Horowitz
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado.
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43
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Abstract
Liquid-liquid phase separation of tau protein has been implicated in normal biological function as well as neurodegenerative diseases, including Alzheimer's. However, knowledge about these links is still scant, and the mechanisms driving tau into liquid droplets are poorly understood. A simplified in vitro system that uses unmodified human tau protein now suggests electrostatic interactions provide the basic instructions underlying liquid droplet formation.
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Affiliation(s)
- Martin Margittai
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208
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44
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Strang KH, Golde TE, Giasson BI. MAPT mutations, tauopathy, and mechanisms of neurodegeneration. J Transl Med 2019; 99:912-928. [PMID: 30742061 PMCID: PMC7289372 DOI: 10.1038/s41374-019-0197-x] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/14/2018] [Accepted: 12/14/2018] [Indexed: 11/09/2022] Open
Abstract
In multiple neurodegenerative diseases, including Alzheimer's disease (AD), a prominent pathological feature is the aberrant aggregation and inclusion formation of the microtubule-associated protein tau. Because of the pathological association, these disorders are often referred to as tauopathies. Mutations in the MAPT gene that encodes tau can cause frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), providing the clearest evidence that tauopathy plays a causal role in neurodegeneration. However, large gaps in our knowledge remain regarding how various FTDP-17-linked tau mutations promote tau aggregation and neurodegeneration, and, more generally, how the tauopathy is linked to neurodegeneration. Herein, we review what is known about how FTDP-17-linked pathogenic MAPT mutations cause disease, with a major focus on the prion-like properties of wild-type and mutant tau proteins. The hypothesized mechanisms by which mutations in the MAPT gene promote tauopathy are quite varied and may not provide definitive insights into how tauopathy arises in the absence of mutation. Further, differences in the ability of tau and mutant tau proteins to support prion-like propagation in various model systems raise questions about the generalizability of this mechanism in various tauopathies. Notably, understanding the mechanisms of tauopathy induction and spread and tau-induced neurodegeneration has important implications for tau-targeting therapeutics.
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Affiliation(s)
- Kevin H Strang
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Todd E Golde
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
- McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Benoit I Giasson
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
- McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, 32610, USA.
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RNA Granules and Their Role in Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:195-245. [DOI: 10.1007/978-3-030-31434-7_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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46
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Galas MC, Bonnefoy E, Buee L, Lefebvre B. Emerging Connections Between Tau and Nucleic Acids. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1184:135-143. [PMID: 32096035 DOI: 10.1007/978-981-32-9358-8_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Connections between tau and nucleic acids have been largely underestimated until recently when several reports highlighted new key roles of tau in relation with DNA and RNA structure, metabolism and integrity, and their implications in the context of tauopathies. Here we focus on recent advances involving tau and nucleic acids in neuronal and non-neuronal cells. Implication of tau and tau pathology in mechanisms regulating genome integrity, chromatin organization and RNA metabolism, highlight the connections between tau and nucleic acid as major mechanisms in neuronal homeostasis and the etiopathology of tauopathies.
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Affiliation(s)
- Marie-Christine Galas
- University of Lille, INSERM, CHU-Lille, UMR-S 1172, Alzheimer & Tauopathies, LabEx DISTALZ, Lille, France.
| | | | - Luc Buee
- University of Lille, INSERM, CHU-Lille, UMR-S 1172, Alzheimer & Tauopathies, LabEx DISTALZ, Lille, France
| | - Bruno Lefebvre
- University of Lille, INSERM, CHU-Lille, UMR-S 1172, Alzheimer & Tauopathies, LabEx DISTALZ, Lille, France
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47
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Cofactors are essential constituents of stable and seeding-active tau fibrils. Proc Natl Acad Sci U S A 2018; 115:13234-13239. [PMID: 30538196 DOI: 10.1073/pnas.1810058115] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amyloid fibrils are cross-β-rich aggregates that are exceptionally stable forms of protein assembly. Accumulation of tau amyloid fibrils is involved in many neurodegenerative diseases, including Alzheimer's disease (AD). Heparin-induced aggregates have been widely used and assumed to be a good tau amyloid fibril model for most biophysical studies. Here we show that mature fibrils made of 4R tau variants, prepared with heparin or RNA, spontaneously depolymerize and release monomers when their cofactors are removed. We demonstrate that the cross-β-sheet assembly formed in vitro with polyanion addition is unstable at room temperature. We furthermore demonstrate high seeding capacity with transgenic AD mouse brain-extracted tau fibrils in vitro that, however, is exhausted after one generation, while supplementation with RNA cofactors resulted in sustained seeding over multiple generations. We suggest that tau fibrils formed in brains are supported by unknown cofactors and inhere higher-quality packing, as reflected in a more distinct conformational arrangement in the mouse fibril-seeded, compared with heparin-induced, tau fibrils. Our study suggests that the role of cofactors in tauopathies is a worthy focus of future studies, as they may be viable targets for diagnosis and therapeutics.
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Weismiller HA, Murphy R, Wei G, Ma B, Nussinov R, Margittai M. Structural disorder in four-repeat Tau fibrils reveals a new mechanism for barriers to cross-seeding of Tau isoforms. J Biol Chem 2018; 293:17336-17348. [PMID: 30242125 PMCID: PMC6231118 DOI: 10.1074/jbc.ra118.005316] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/11/2018] [Indexed: 12/14/2022] Open
Abstract
The intracellular deposition of fibrils composed of the microtubule-associated protein Tau is a characteristic feature of Alzheimer's disease (AD) and other fatal neurodegenerative disorders collectively known as tauopathies. Short Tau fibrils spread intracerebrally through transfer between interconnected neurons. Once taken up by a recipient cell, Tau fibrils recruit Tau monomers onto their ends. Based on the number of microtubule-binding repeats, there are two distinct groups of Tau isoforms: three-repeat (3R) Tau and four-repeat (4R) Tau. In AD, all Tau isoforms are deposited, whereas in other tauopathies, only 3R or 4R Tau isoforms are deposited. The molecular basis for these isoform-specific depositions is poorly understood, although conformation-based cross-seeding barriers are key. Here, we used sedimentation assays, EPR spectroscopy, and other structural readouts to better understand the cross-seeding barriers of 4R Tau fibrils. We observed that fibrils formed from truncated Tau (K18), but not full-length Tau (htau40), exhibit a barrier that inhibits 3R Tau recruitment. Investigating an array of differently sized fragments, we found that the Tau C terminus modulates the cross-seeding barrier and that the N terminus plays a synergistic role. Two disease-associated Tau variants, P301S and P301L, also established strong cross-seeding barriers. EPR analysis indicated that fibrils seeded with truncated and mutated Tau, but not htau40, are structurally disordered in the second half of repeat four and onward. These findings suggest that the disorder in this region diminishes the ability of 4R Tau fibrils to recruit 3R Tau monomers, revealing a new mechanism for Tau cross-seeding barriers.
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Affiliation(s)
- Hilary A Weismiller
- From the Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208
| | - Rachel Murphy
- From the Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208
| | - Guanghong Wei
- the Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Science, Ministry of Education, Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200433, China
| | - Buyong Ma
- the Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702, and
| | - Ruth Nussinov
- the Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, NCI, National Institutes of Health, Frederick, Maryland 21702, and
- the Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Martin Margittai
- From the Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208,
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Nizynski B, Dzwolak W, Nieznanski K. Amyloidogenesis of Tau protein. Protein Sci 2017; 26:2126-2150. [PMID: 28833749 DOI: 10.1002/pro.3275] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/16/2017] [Accepted: 08/16/2017] [Indexed: 11/08/2022]
Abstract
The role of microtubule-associated protein Tau in neurodegeneration has been extensively investigated since the discovery of Tau amyloid aggregates in the brains of patients with Alzheimer's disease (AD). The process of formation of amyloid fibrils is known as amyloidogenesis and attracts much attention as a potential target in the prevention and treatment of neurodegenerative conditions linked to protein aggregation. Cerebral deposition of amyloid aggregates of Tau is observed not only in AD but also in numerous other tauopathies and prion diseases. Amyloidogenesis of intrinsically unstructured monomers of Tau can be triggered by mutations in the Tau gene, post-translational modifications, or interactions with polyanionic molecules and aggregation-prone proteins/peptides. The self-assembly of amyloid fibrils of Tau shares a number of characteristic features with amyloidogenesis of other proteins involved in neurodegenerative diseases. For example, in vitro experiments have demonstrated that the nucleation phase, which is the rate-limiting stage of Tau amyloidogenesis, is shortened in the presence of fragmented preformed Tau fibrils acting as aggregation templates ("seeds"). Accordingly, Tau aggregates released by tauopathy-affected neurons can spread the neurodegenerative process in the brain through a prion-like mechanism, originally described for the pathogenic form of prion protein. Moreover, Tau has been shown to form amyloid strains-structurally diverse self-propagating aggregates of potentially various pathological effects, resembling in this respect prion strains. Here, we review the current literature on Tau aggregation and discuss mechanisms of propagation of Tau amyloid in the light of the prion-like paradigm.
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Affiliation(s)
- Bartosz Nizynski
- College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, 2C Banacha Str, Warsaw, 02-097, Poland.,Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str, Warsaw, 02-093, Poland
| | - Wojciech Dzwolak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, 1 Pasteur Str, Warsaw, 02-093, Poland
| | - Krzysztof Nieznanski
- Department of Biochemistry, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str, Warsaw, 02-093, Poland
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Abstract
Aggregation of the amyloid-β (Aβ) peptide is strongly correlated with Alzheimer's disease (AD). Recent research has improved our understanding of the kinetics of amyloid fibril assembly and revealed new details regarding different stages in plaque formation. Presently, interest is turning toward studying this process in a holistic context, focusing on cellular components which interact with the Aβ peptide at various junctures during aggregation, from monomer to cross-β amyloid fibrils. However, even in isolation, a multitude of factors including protein purity, pH, salt content, and agitation affect Aβ fibril formation and deposition, often producing complicated and conflicting results. The failure of numerous inhibitors in clinical trials for AD suggests that a detailed examination of the complex interactions that occur during plaque formation, including binding of carbohydrates, lipids, nucleic acids, and metal ions, is important for understanding the diversity of manifestations of the disease. Unraveling how a variety of key macromolecular modulators interact with the Aβ peptide and change its aggregation properties may provide opportunities for developing therapies. Since no protein acts in isolation, the interplay of these diverse molecules may differentiate disease onset, progression, and severity, and thus are worth careful consideration.
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Affiliation(s)
- Katie L Stewart
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK.
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK.
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