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Acosta K, Brue CR, Kim HJ, Holubovska P, Mayne L, Murakami K, Rhoades E. Structural Insights into the Role of the Proline Rich Region in Tau Function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.20.614010. [PMID: 39386529 PMCID: PMC11463496 DOI: 10.1101/2024.09.20.614010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2024]
Abstract
Tau is a microtubule-associated protein that plays an important role in modulating axonal microtubules in neurons. Intracellular tau aggregates are found in a broad class of disorders, including Alzheimer's disease, termed tauopathies. Tau is an intrinsically disordered protein, and its structural disorder appears to be critical to its microtubule-related functions. Tubulin binding sites are found in tau's proline-rich region (PRR), microtubule binding repeats (MTBR: R1-R4), and pseudo-repeat, R'. While many post-translational modifications have been identified on tau, phosphorylation sites, which both regulate tubulin dimer and microtubule interactions and are correlated with disease, cluster with high frequency within the PRR. Here, we use fluorescence correlation spectroscopy and structural mass spectrometry techniques to characterize the impact of phosphomimic mutations in the PRR on tubulin dimer binding and probe the structure of the PRR-tubulin dimer complex. We find that phosphomimics cumulatively diminish tubulin dimer binding and slow microtubule polymerization. Additionally, we map two ∼15 residue regions of the PRR as primary tubulin dimer binding sites and propose a model in which PRR enhances lateral interactions between tubulin dimers, complementing the longitudinal interactions observed for MTBR. Together these measurements provide insight into the previously overlooked relevance of tau's PRR in functional interactions with tubulin. GRAPHICAL ABSTRACT
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Kim AY, Al Jerdi S, MacDonald R, Triggle CR. Alzheimer's disease and its treatment-yesterday, today, and tomorrow. Front Pharmacol 2024; 15:1399121. [PMID: 38868666 PMCID: PMC11167451 DOI: 10.3389/fphar.2024.1399121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 04/25/2024] [Indexed: 06/14/2024] Open
Abstract
Alois Alzheimer described the first patient with Alzheimer's disease (AD) in 1907 and today AD is the most frequently diagnosed of dementias. AD is a multi-factorial neurodegenerative disorder with familial, life style and comorbidity influences impacting a global population of more than 47 million with a projected escalation by 2050 to exceed 130 million. In the USA the AD demographic encompasses approximately six million individuals, expected to increase to surpass 13 million by 2050, and the antecedent phase of AD, recognized as mild cognitive impairment (MCI), involves nearly 12 million individuals. The economic outlay for the management of AD and AD-related cognitive decline is estimated at approximately 355 billion USD. In addition, the intensifying prevalence of AD cases in countries with modest to intermediate income countries further enhances the urgency for more therapeutically and cost-effective treatments and for improving the quality of life for patients and their families. This narrative review evaluates the pathophysiological basis of AD with an initial focus on the therapeutic efficacy and limitations of the existing drugs that provide symptomatic relief: acetylcholinesterase inhibitors (AChEI) donepezil, galantamine, rivastigmine, and the N-methyl-D-aspartate receptor (NMDA) receptor allosteric modulator, memantine. The hypothesis that amyloid-β (Aβ) and tau are appropriate targets for drugs and have the potential to halt the progress of AD is critically analyzed with a particular focus on clinical trial data with anti-Aβ monoclonal antibodies (MABs), namely, aducanumab, lecanemab and donanemab. This review challenges the dogma that targeting Aβ will benefit the majority of subjects with AD that the anti-Aβ MABs are unlikely to be the "magic bullet". A comparison of the benefits and disadvantages of the different classes of drugs forms the basis for determining new directions for research and alternative drug targets that are undergoing pre-clinical and clinical assessments. In addition, we discuss and stress the importance of the treatment of the co-morbidities, including hypertension, diabetes, obesity and depression that are known to increase the risk of developing AD.
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Affiliation(s)
- A. Y. Kim
- Medical Education, Weill Cornell Medicine—Qatar, Doha, Qatar
| | | | - R. MacDonald
- Health Sciences Library, Weill Cornell Medicine—Qatar, Doha, Qatar
| | - C. R. Triggle
- Department of Pharmacology and Medical Education, Weill Cornell Medicine—Qatar, Doha, Qatar
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Crha R, Kozeleková A, Hofrová A, Iľkovičová L, Gašparik N, Kadeřávek P, Hritz J. Hiding in plain sight: Complex interaction patterns between Tau and 14-3-3ζ protein variants. Int J Biol Macromol 2024; 266:130802. [PMID: 38492709 DOI: 10.1016/j.ijbiomac.2024.130802] [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: 12/22/2023] [Revised: 03/05/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024]
Abstract
Tau protein is an intrinsically disordered protein that plays a key role in Alzheimer's disease (AD). In brains of AD patients, Tau occurs abnormally phosphorylated and aggregated in neurofibrillary tangles (NFTs). Together with Tau, 14-3-3 proteins - abundant cytosolic dimeric proteins - were found colocalized in the NFTs. However, so far, the molecular mechanism of the process leading to pathological changes in Tau structure as well as the direct involvement of 14-3-3 proteins are not well understood. Here, we aimed to reveal the effects of phosphorylation by protein kinase A (PKA) on Tau structural preferences and provide better insight into the interaction between Tau and 14-3-3 proteins. We also addressed the impact of monomerization-inducing phosphorylation of 14-3-3 at S58 on the binding to Tau protein. Using multidimensional nuclear magnetic resonance spectroscopy (NMR), chemical cross-linking analyzed by mass spectrometry (MS) and PAGE, we unveiled differences in their binding affinity, stoichiometry, and interfaces with single-residue resolution. We revealed that the interaction between 14-3-3 and Tau proteins is mediated not only via the 14-3-3 amphipathic binding grooves, but also via less specific interactions with 14-3-3 protein surface and, in the case of monomeric 14-3-3, also partially via the exposed dimeric interface. In addition, the hyperphosphorylation of Tau changes its affinity to 14-3-3 proteins. In conclusion, we propose quite complex interaction mode between the Tau and 14-3-3 proteins.
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Affiliation(s)
- Radek Crha
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Aneta Kozeleková
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Alena Hofrová
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Lucia Iľkovičová
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Norbert Gašparik
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Kadeřávek
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jozef Hritz
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
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Chinnathambi S, Chidambaram H. G-protein coupled receptors regulates Tauopathy in neurodegeneration. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2024; 141:467-493. [PMID: 38960483 DOI: 10.1016/bs.apcsb.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
In Alzheimer's disease, the microtubule-associated protein, Tau misfolds to form aggregates and filaments in the intra- and extracellular region of neuronal cells. Microglial cells are the resident brain macrophage cells involved in constant surveillance and activated by the extracellular deposits. Purinergic receptors are involved in the chemotactic migration of microglial cells towards the site of inflammation. From our recent study, we have observed that the microglial P2Y12 receptor is involved in phagocytosis of full-length Tau species such as monomers, oligomers and aggregates by actin-driven chemotaxis. This study shows the interaction of repeat-domain of Tau (TauRD) with the microglial P2Y12 receptor and the corresponding residues for interaction have been analyzed by various in-silico approaches. In the cellular studies, TauRD was found to interact with microglial P2Y12R and induces its cellular expression confirmed by co-immunoprecipitation and western blot analysis. Furthermore, the P2Y12R-mediated TauRD internalization has demonstrated activation of microglia with an increase in the Iba1 level, and TauRD becomes accumulated at the peri-nuclear region for the degradation.
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Affiliation(s)
- Subashchandrabose Chinnathambi
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India.
| | - Hariharakrishnan Chidambaram
- Department of Neurochemistry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Institute of National Importance, Bangalore, Karnataka, India
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Sari L, Bali S, Joachimiak LA, Lin MM. Hairpin trimer transition state of amyloid fibril. Nat Commun 2024; 15:2756. [PMID: 38553453 PMCID: PMC10980705 DOI: 10.1038/s41467-024-46446-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 02/28/2024] [Indexed: 04/02/2024] Open
Abstract
Protein fibril self-assembly is a universal transition implicated in neurodegenerative diseases. Although fibril structure/growth are well characterized, fibril nucleation is poorly understood. Here, we use a computational-experimental approach to resolve fibril nucleation. We show that monomer hairpin content quantified from molecular dynamics simulations is predictive of experimental fibril formation kinetics across a tau motif mutant library. Hairpin trimers are predicted to be fibril transition states; one hairpin spontaneously converts into the cross-beta conformation, templating subsequent fibril growth. We designed a disulfide-linked dimer mimicking the transition state that catalyzes fibril formation, measured by ThT fluorescence and TEM, of wild-type motif - which does not normally fibrillize. A dimer compatible with extended conformations but not the transition-state fails to nucleate fibril at any concentration. Tau repeat domain simulations show how long-range interactions sequester this motif in a mutation-dependent manner. This work implies that different fibril morphologies could arise from disease-dependent hairpin seeding from different loci.
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Affiliation(s)
- Levent Sari
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sofia Bali
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Milo M Lin
- Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Alhadidy MM, Kanaan NM. Biochemical approaches to assess the impact of post-translational modifications on pathogenic tau conformations using recombinant protein. Biochem Soc Trans 2024; 52:301-318. [PMID: 38348781 PMCID: PMC10903483 DOI: 10.1042/bst20230596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/29/2024]
Abstract
Tau protein is associated with many neurodegenerative disorders known as tauopathies. Aggregates of tau are thought of as a main contributor to neurodegeneration in these diseases. Increasingly, evidence points to earlier, soluble conformations of abnormally modified monomers and multimeric tau as toxic forms of tau. The biological processes driving tau from physiological species to pathogenic conformations remain poorly understood, but certain avenues are currently under investigation including the functional consequences of various pathological tau changes (e.g. mutations, post-translational modifications (PTMs), and protein-protein interactions). PTMs can regulate several aspects of tau biology such as proteasomal and autophagic clearance, solubility, and aggregation. Moreover, PTMs can contribute to the transition of tau from normal to pathogenic conformations. However, our understating of how PTMs specifically regulate the transition of tau into pathogenic conformations is partly impeded by the relative lack of structured frameworks to assess and quantify these conformations. In this review, we describe a set of approaches that includes several in vitro assays to determine the contribution of PTMs to tau's transition into known pathogenic conformations. The approaches begin with different methods to create recombinant tau proteins carrying specific PTMs followed by validation of the PTMs status. Then, we describe a set of biochemical and biophysical assays that assess the contribution of a given PTM to different tau conformations, including aggregation, oligomerization, exposure of the phosphatase-activating domain, and seeding. Together, these approaches can facilitate the advancement of our understanding of the relationships between PTMs and tau conformations.
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Affiliation(s)
- Mohammed M. Alhadidy
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, U.S.A
- Neuroscience Program, Michigan State University, East Lansing, MI, U.S.A
| | - Nicholas M. Kanaan
- Department of Translational Neuroscience, College of Human Medicine, Michigan State University, Grand Rapids, MI, U.S.A
- Neuroscience Program, Michigan State University, East Lansing, MI, U.S.A
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Martinho M, Allegro D, Etienne E, Lohberger C, Bonucci A, Belle V, Barbier P. Structural Flexibility of Tau in Its Interaction with Microtubules as Viewed by Site-Directed Spin Labeling EPR Spectroscopy. Methods Mol Biol 2024; 2754:55-75. [PMID: 38512660 DOI: 10.1007/978-1-0716-3629-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Tau is a microtubule-associated protein that belongs to the Intrinsically Disordered Proteins (IDPs) family. IDPs or Intrinsically Disordered Regions (IDRs) play key roles in protein interaction networks and their dysfunctions are often related to severe diseases. Defined by their lack of stable secondary and tertiary structures in physiological conditions while being functional, these proteins use their inherent structural flexibility to adapt to and interact with various binding partners. Knowledges on the structural dynamics of IDPs and their different conformers are crucial to finely decipher fundamental biological processes controlled by mechanisms such as conformational adaptations or switches, induced fit, or conformational selection events. Different mechanisms of binding have been proposed: among them, the so-called folding-upon-binding in which the IDP adopts a certain conformation upon interacting with a partner protein, or the formation of a "fuzzy" complex in which the IDP partly keeps its dynamical character at the surface of its partner. The dynamical nature and physicochemical properties of unbound as well as bound IDPs make this class of proteins particularly difficult to characterize by classical bio-structural techniques and require specific approaches for the fine description of their inherent dynamics.Among other techniques, Site-Directed Spin Labeling combined with Electron Paramagnetic Resonance (SDSL-EPR) spectroscopy has gained much interest in this last decade for the study of IDPs. SDSL-EPR consists in grafting a paramagnetic label (mainly a nitroxide radical) at selected site(s) of the macromolecule under interest followed by its observation using and/or combining different EPR strategies. These nitroxide spin labels detected by continuous wave (cw) EPR spectroscopy are used as perfect reporters or "spy spins" of their local environment, being able to reveal structural transitions, folding/unfolding events, etc. Another approach is based on the measurement of inter-label distance distributions in the 1.5-8.0 nm range using pulsed dipolar EPR experiments, such as Double Electron-Electron Resonance (DEER) spectroscopy. The technique is then particularly well suited to study the behavior of Tau in its interaction with its physiological partner: microtubules (MTs). In this chapter we provide a detailed experimental protocol for the labeling of Tau protein and its EPR study while interacting with preformed (Paclitaxel-stabilized) MTs, or using Tau as MT inducer. We show how the choice of nitroxide label can be crucial to obtain functional information on Tau/tubulin complexes.
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Affiliation(s)
| | - Diane Allegro
- Aix Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | | | - Cynthia Lohberger
- Aix Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | | | | | - Pascale Barbier
- Aix Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France.
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Li L, Nguyen BA, Mullapudi V, Li Y, Saelices L, Joachimiak LA. Disease-associated patterns of acetylation stabilize tau fibril formation. Structure 2023; 31:1025-1037.e4. [PMID: 37348495 PMCID: PMC10527703 DOI: 10.1016/j.str.2023.05.020] [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: 02/07/2023] [Revised: 05/03/2023] [Accepted: 05/26/2023] [Indexed: 06/24/2023]
Abstract
Assembly of tau into beta-sheet-rich amyloids dictates the pathology of a diversity of diseases. Lysine acetylation has been proposed to drive tau amyloid assembly, but no direct mechanism has emerged. Using tau fragments, we identify patterns of acetylation that flank amyloidogenic motifs on the tau fragments that promote rapid fibril assembly. We determined a 3.9 Å cryo-EM amyloid fibril structure assembled from an acetylated tau fragment uncovering how lysine acetylation can mediate gain-of-function interactions. Comparison of the structure to an ex vivo tauopathy fibril reveals regions of structural similarity. Finally, we show that fibrils encoding disease-associated patterns of acetylation are active in cell-based tau aggregation assays. Our data uncover the dual role of lysine residues in limiting tau aggregation while their acetylation leads to stabilizing pro-aggregation interactions. Design of tau sequence with specific acetylation patterns may lead to controllable tau aggregation to direct folding of tau into distinct amyloid folds.
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Affiliation(s)
- Li Li
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Binh A Nguyen
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vishruth Mullapudi
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yang Li
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lorena Saelices
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, 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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Paterno G, Torrellas J, Bell BM, Gorion KMM, Quintin SS, Hery GP, Prokop S, Giasson BI. Novel Conformation-Dependent Tau Antibodies Are Modulated by Adjacent Phosphorylation Sites. Int J Mol Sci 2023; 24:13676. [PMID: 37761979 PMCID: PMC10530490 DOI: 10.3390/ijms241813676] [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: 07/18/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Tau proteins within the adult central nervous system (CNS) are found to be abnormally aggregated into heterogeneous filaments in neurodegenerative diseases, termed tauopathies. These tau inclusions are pathological hallmarks of Alzheimer's disease (AD), Pick's disease (PiD), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP). The neuropathological hallmarks of these diseases burden several cell types within the CNS, and have also been shown to be abundantly phosphorylated. The mechanism(s) by which tau aggregates in the CNS is not fully known, but it is hypothesized that hyperphosphorylated tau may precede and further promote filament formation, leading to the production of these pathological inclusions. In the studies herein, we generated and thoroughly characterized two novel conformation-dependent tau monoclonal antibodies that bind to residues Pro218-Glu222, but are sensitive to denaturing conditions and highly modulated by adjacent downstream phosphorylation sites. These epitopes are present in the neuropathological hallmarks of several tauopathies, including AD, PiD, CBD, and PSP. These novel antibodies will further enable investigation of tau-dependent pathological inclusion formation and enhance our understanding of the phosphorylation signatures within tauopathies with the possibility of new biomarker developments.
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Affiliation(s)
- Giavanna Paterno
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
| | - Jose Torrellas
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
| | - Brach M. Bell
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
| | - Kimberly-Marie M. Gorion
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
| | - Stephan S. Quintin
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
| | - Gabriela P. Hery
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
- Department of Pathology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Stefan Prokop
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
- Department of Pathology, 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; (G.P.); (J.T.); (B.M.B.); (K.-M.M.G.); (S.S.Q.)
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, FL 32610, USA; (G.P.H.); (S.P.)
- McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL 32610, USA
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Oliyantakath Hassan MS, Abdul Vahid A, Sahayaraj AE, Viswanathan R, Vijayan V. NMR Relaxation Experiments Probe Monomer-Fibril Interaction and Identify Critical Interacting Residues Responsible for Distinct Tau Fibril Morphologies. J Phys Chem Lett 2023; 14:6583-6591. [PMID: 37458827 DOI: 10.1021/acs.jpclett.3c00912] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Tau aggregation is governed by secondary processes, a major pathological pathway for tau protein fibril propagation, yet its molecular mechanism remains unknown. This work uses saturation transfer and lifetime line-broadening experiments to identify the critical residues involved in these secondary processes. Distinct residue-specific NMR relaxation parameters were obtained for the truncated three repeat tau construct (K19) in equilibrium with structurally different, self-aggregated (saK19) or heparin-induced (hK19) fibrils. The interacting residues are restricted to R3 repeat for hK19 and to R3, R4, and R' repeats for saK19 fibrils. Furthermore, the relaxation profiles of tau monomers in equilibrium with the structurally comparable, in vitro pathological fibrils (tauAD and tauCTE) were similar but distinct from hK19 or saK19 fibrils. Thus, residue-specific relaxation identifies the important residues involved in the binding of monomers to the fibrils. The relaxation profile of the monomers in equilibrium with the NMR invisible fibril seeds potentially distinguishes the distinct structures of tau fibrils.
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Affiliation(s)
| | - Arshad Abdul Vahid
- School of Chemistry, IISER-Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Allwin Ebenezer Sahayaraj
- School of Chemistry, IISER-Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Renjith Viswanathan
- School of Chemistry, IISER-Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Vinesh Vijayan
- School of Chemistry, IISER-Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram, Kerala 695551, India
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11
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El Mammeri N, Duan P, Dregni AJ, Hong M. Amyloid fibril structures of tau: Conformational plasticity of the second microtubule-binding repeat. SCIENCE ADVANCES 2023; 9:eadh4731. [PMID: 37450599 PMCID: PMC10348678 DOI: 10.1126/sciadv.adh4731] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
The intrinsically disordered protein tau associates with microtubules in neurons but aggregates into cross-β amyloid fibrils that propagate in neurodegenerative brains. Different tauopathies have different structures for the rigid fibril core. To understand the molecular basis of tau assembly into different polymorphs, here we use solid-state nuclear magnetic resonance (NMR) spectroscopy to determine the structure of a tau protein that includes all microtubule-binding repeats and a proline-rich domain. This P2R tau assembles into well-ordered filaments when induced by heparin. Two- and three-dimensional NMR spectra indicate that R2 and R3 repeats constitute the rigid β-sheet core of the fibril. Unexpectedly, the amino-terminal half of R2 forms a β-arch at ambient temperature (24°C) but a continuous β-strand at 12°C, which dimerizes with the R2 of another protofilament. This temperature-dependent structure indicates that R2 is conformationally more plastic than the R3 domain. The distinct conformational stabilities of different microtubule-binding repeats give insight into the energy landscape of tau fibril formation.
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Affiliation(s)
- Nadia El Mammeri
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
| | - Pu Duan
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
| | - Aurelio J. Dregni
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
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12
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Christensen KR, Combs B, Richards C, Grabinski T, Alhadidy MM, Kanaan NM. Phosphomimetics at Ser199/Ser202/Thr205 in Tau Impairs Axonal Transport in Rat Hippocampal Neurons. Mol Neurobiol 2023; 60:3423-3438. [PMID: 36859689 PMCID: PMC10122714 DOI: 10.1007/s12035-023-03281-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 02/16/2023] [Indexed: 03/03/2023]
Abstract
Our understanding of the biological functions of the tau protein now includes its role as a scaffolding protein involved in signaling regulation, which also has implications for tau-mediated dysfunction and degeneration in Alzheimer's disease and other tauopathies. Recently, we found that pseudophosphorylation at sites linked to the pathology-associated AT8 phosphoepitope of tau disrupts normal fast axonal transport through a protein phosphatase 1 (PP1)-dependent pathway in squid axoplasm. Activation of the pathway and the resulting transport deficits required tau's N-terminal phosphatase-activating domain (PAD) and PP1 but the connection between tau and PP1 was not well defined. Here, we studied functional interactions between tau and PP1 isoforms and their effects on axonal transport in mammalian neurons. First, we found that wild-type tau interacted with PP1α and PP1γ primarily through its microtubule-binding repeat domain. Pseudophosphorylation of tau at S199/S202/T205 (psTau) increased PAD exposure, enhanced interactions with PP1γ, and increased active PP1γ levels in mammalian cells. Expression of psTau also significantly impaired axonal transport in primary rat hippocampal neurons. Deletion of PAD in psTau significantly reduced the interaction with PP1γ, eliminated increases of active PP1γ levels, and rescued axonal transport impairment in neurons. These data suggest that a functional consequence of phosphorylation within S199-T205 in tau, which occurs in AD and several other tauopathies, may be aberrant interaction with and activation of PP1γ and subsequent axonal transport disruption in a PAD-dependent fashion.
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Affiliation(s)
- Kyle R Christensen
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Benjamin Combs
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Collin Richards
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Tessa Grabinski
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Mohammed M Alhadidy
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA.
- Neuroscience Program, Michigan State University, East Lansing, MI, 48824, USA.
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, 49503, USA.
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13
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Hsiao AS, Huang JY. Microtubule Regulation in Plants: From Morphological Development to Stress Adaptation. Biomolecules 2023; 13:biom13040627. [PMID: 37189374 DOI: 10.3390/biom13040627] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/09/2023] [Accepted: 03/25/2023] [Indexed: 04/03/2023] Open
Abstract
Microtubules (MTs) are essential elements of the eukaryotic cytoskeleton and are critical for various cell functions. During cell division, plant MTs form highly ordered structures, and cortical MTs guide the cell wall cellulose patterns and thus control cell size and shape. Both are important for morphological development and for adjusting plant growth and plasticity under environmental challenges for stress adaptation. Various MT regulators control the dynamics and organization of MTs in diverse cellular processes and response to developmental and environmental cues. This article summarizes the recent progress in plant MT studies from morphological development to stress responses, discusses the latest techniques applied, and encourages more research into plant MT regulation.
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14
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Chen D, Bali S, Singh R, Wosztyl A, Mullapudi V, Vaquer-Alicea J, Jayan P, Melhem S, Seelaar H, van Swieten JC, Diamond MI, Joachimiak LA. FTD-tau S320F mutation stabilizes local structure and allosterically promotes amyloid motif-dependent aggregation. Nat Commun 2023; 14:1625. [PMID: 36959205 PMCID: PMC10036635 DOI: 10.1038/s41467-023-37274-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 03/10/2023] [Indexed: 03/25/2023] Open
Abstract
Amyloid deposition of the microtubule-associated protein tau is associated with neurodegenerative diseases. In frontotemporal dementia with abnormal tau (FTD-tau), missense mutations in tau enhance its aggregation propensity. Here we describe the structural mechanism for how an FTD-tau S320F mutation drives spontaneous aggregation, integrating data from in vitro, in silico and cellular experiments. We find that S320F stabilizes a local hydrophobic cluster which allosterically exposes the 306VQIVYK311 amyloid motif; identify a suppressor mutation that destabilizes S320F-based hydrophobic clustering reversing the phenotype in vitro and in cells; and computationally engineer spontaneously aggregating tau sequences through optimizing nonpolar clusters surrounding the S320 position. We uncover a mechanism for regulating tau aggregation which balances local nonpolar contacts with long-range interactions that sequester amyloid motifs. Understanding this process may permit control of tau aggregation into structural polymorphs to aid the design of reagents targeting disease-specific tau conformations.
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Affiliation(s)
- Dailu Chen
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sofia Bali
- Molecular Biophysics Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ruhar Singh
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Aleksandra Wosztyl
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Vishruth Mullapudi
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jaime Vaquer-Alicea
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Parvathy Jayan
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Shamiram Melhem
- Department of Neurology & Alzheimer Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - Harro Seelaar
- Department of Neurology & Alzheimer Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - John C van Swieten
- Department of Neurology & Alzheimer Center, Erasmus Medical Center, Rotterdam, Netherlands
| | - Marc I Diamond
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, Peter O'Donnell Jr. Brain Institute, 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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15
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Biomolecular condensation involving the cytoskeleton. Brain Res Bull 2023; 194:105-117. [PMID: 36690162 DOI: 10.1016/j.brainresbull.2023.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/07/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Biomolecular condensation of proteins contributes to the organization of the cytoplasm and nucleoplasm. A number of condensation processes appear to be directly involved in regulating the structure, function and dynamics of the cytoskeleton. Liquid-liquid phase separation of cytoskeleton proteins, together with polymerization modulators, promotes cytoskeletal fiber nucleation and branching. Furthermore, the attachment of protein condensates to the cytoskeleton can contribute to cytoskeleton stability and organization, regulate transport, create patterns of functional reaction containers, and connect the cytoskeleton with membranes. Surface-bound condensates can exert and buffer mechanical forces that give stability and flexibility to the cytoskeleton, thus, may play a large role in cell biology. In this review, we introduce the concept and role of cellular biomolecular condensation, explain its special function on cytoskeletal fiber surfaces, and point out potential definition and experimental caveats. We review the current literature on protein condensation processes related to the actin, tubulin, and intermediate filament cytoskeleton, and discuss some of them in the context of neurobiology. In summary, we provide an overview about biomolecular condensation in relation to cytoskeleton structure and function, which offers a base for the exploration and interpretation of cytoskeletal condensates in neurobiology.
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16
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Zou Y, Guan L, Tan J, Qi B, Wang Y, Zhang Q, Sun Y. Atomistic Insights into the Inhibitory Mechanism of Tyrosine Phosphorylation against the Aggregation of Human Tau Fragment PHF6. J Phys Chem B 2023; 127:335-345. [PMID: 36594671 DOI: 10.1021/acs.jpcb.2c07568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abnormal aggregation of the microtubule-associated protein tau into intracellular fibrillary inclusions is characterized as the hallmark of tauopathies, including Alzheimer's disease and chronic traumatic encephalopathy. The hexapeptide 306VQIVYK311 (PHF6) of R3 plays an important role in the aggregation of tau. Recent experimental studies reported that phosphorylation of residue tyrosine 310 (Y310) could decrease the propensity of PHF6 to form fibrils and inhibit tau aggregation. However, the underlying inhibitory mechanism is not well understood. In this work, we systematically investigated the influences of phosphorylation on the conformational ensembles and oligomerization dynamics of PHF6 by performing extensive all-atom molecular dynamics (MD) simulations. Our replica exchange MD simulations demonstrate that Y310 phosphorylation could effectively suppress the formation of β-structure and shift PHF6 oligomers toward coil-rich aggregates. The interaction analyses show that hydrogen bonding and hydrophobic interactions among PHF6 peptides, as well as Y310-Y310 π-π stacking and I308-Y310 CH-π interactions, are weakened by phosphorylation. Additional microsecond MD simulations show that Y310 phosphorylation could inhibit the oligomerization of PHF6 by preventing the formation of large β-sheet oligomers and multi-layer β-sheet aggregates. This study provides mechanistic insights into the phosphorylation-inhibited tau aggregation, which may be helpful for the in-depth understanding of the pathogenesis of tauopathies.
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Affiliation(s)
- Yu Zou
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 886 Yuhangtang Road, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Lulu Guan
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 886 Yuhangtang Road, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Jingwang Tan
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 886 Yuhangtang Road, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Bote Qi
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 886 Yuhangtang Road, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Ying Wang
- Department of Physics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211, People's Republic of China
| | - Qingwen Zhang
- College of Physical Education and Training, Shanghai University of Sport, 399 Changhai Road, Shanghai 200438, People's Republic of China
| | - Yunxiang Sun
- Department of Physics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211, People's Republic of China
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17
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Hochmair J, Exner C, Betzel C, Mandelkow E, Wegmann S. Light Microscopy and Dynamic Light Scattering to Study Liquid-Liquid Phase Separation of Tau Proteins In Vitro. Methods Mol Biol 2023; 2551:225-243. [PMID: 36310206 DOI: 10.1007/978-1-0716-2597-2_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Tau is an intrinsically disordered protein that binds and stabilizes axonal microtubules (MTs) in neurons of the central nervous system. The binding of Tau to MTs is mediated by its repeat domain and flanking proline-rich domains. The positively charged (basic) C-terminal half of Tau also mediates the assembly Tau into fibrillar aggregates in Alzheimer's disease (AD) and tauopathy brains. In recent years, another assembly form of Tau has been identified: Tau can undergo liquid-liquid phase separation (LLPS), which leads to its condensation into liquid-dense phases, either by complex coacervation with polyanions like heparin or RNA or through "self-coacervation" at high Tau concentrations. Condensation of Tau in the absence of polyanions can be enhanced by the presence of molecular crowding agents in a dilute Tau solution. In vitro experiments using recombinant purified Tau are helpful to study the physicochemical determinants of Tau LLPS, which can then be extrapolated into the cellular context. Tau condensation is a new aspect of Tau biology that may play a role for the initiation of Tau aggregation, but also for its physiological function(s), for example, the binding to microtubules. Here we describe how to study the condensation of Tau in vitro using light microscopy, including fluorescence recovery after photobleaching (FRAP), to assess the shape and molecular diffusion in the condensates, a proxy for the degree of condensate percolation. We also describe turbidity measurements of condensate-containing solutions to assess the overall amount of LLPS and time-resolved dynamic light scattering (trDLS) to study the formation and size of Tau condensates.
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Affiliation(s)
- Janine Hochmair
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Christian Exner
- University Hamburg, Institute for Biochemistry and Molecular Biology, Laboratory for Structural Biology of Infection and Inflammation, Hamburg, Germany
| | - Christian Betzel
- University Hamburg, Institute for Biochemistry and Molecular Biology, Laboratory for Structural Biology of Infection and Inflammation, Hamburg, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Research Center CAESAR, Bonn, Germany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.
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18
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Murray A, Yan L, Gibson JM, Liu J, Eliezer D, Lippens G, Zhang F, Linhardt RJ, Zhao J, Wang C. Proline-Rich Region II (PRR2) Plays an Important Role in Tau-Glycan Interaction: An NMR Study. Biomolecules 2022; 12:1573. [PMID: 36358923 PMCID: PMC9687896 DOI: 10.3390/biom12111573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 10/06/2022] [Accepted: 10/09/2022] [Indexed: 01/09/2023] Open
Abstract
(1) Background: Prion-like transcellular spreading of tau pathology in Alzheimer's disease (AD) is mediated by tau binding to the cell-surface glycan heparan sulfate (HS). However, the structural determinants for tau-HS interaction are not well understood. (2) Methods and Results: Binding-site mapping using NMR showed two major binding regions in full-length tau responsible for heparin interaction. Thus, two tau constructs, tau PRR2* and tau R2*, were designed to investigate the molecular details at the tau-heparin binding interface. The 2D 1H-15N HSQC of tau PRR2* and tau R2* lacked dispersion, which is characteristic for intrinsically disordered proteins. NMR titration of Arixtra into 15N-labeled tau R2* induced large chemical shift perturbations (CSPs) in 275VQIINK280 and downstream residues K281-D283, in which L282 and I278 displayed the largest shifts. NMR titration of Arixtra into 15N-labeled tau PRR2* induced the largest CSPs for residue R209 followed by residues S210 and R211. Residue-based CSP fitting showed that tau PRR2*-Arixtra interaction had a much stronger binding affinity (0.37-0.67 mM) than that of tau R2*-Arixtra (1.90-5.12 mM) interaction. (3) Conclusions: Our results suggested that PRR2 is a crucial domain for tau-heparin and tau-HS interaction.
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Affiliation(s)
- Anqesha Murray
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
| | - Lufeng Yan
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
| | - James M. Gibson
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27514, USA
| | - David Eliezer
- Program in Structural Biology, Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
| | - Guy Lippens
- Toulouse Biotechnology Institute, CNRS, INRA, INSA, University of Toulouse, 31077 Toulouse, France
| | - Fuming Zhang
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
| | - Robert J. Linhardt
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
| | - Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
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19
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Cario A, Wickramasinghe SP, Rhoades E, Berger CL. The N-terminal disease-associated R5L Tau mutation increases microtubule shrinkage rate due to disruption of microtubule-bound Tau patches. J Biol Chem 2022; 298:102526. [PMID: 36162501 PMCID: PMC9589210 DOI: 10.1016/j.jbc.2022.102526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/25/2022] Open
Abstract
Regulation of the neuronal microtubule cytoskeleton is achieved through the coordination of microtubule-associated proteins (MAPs). MAP-Tau, the most abundant MAP in the axon, functions to modulate motor motility, participate in signaling cascades, as well as directly mediate microtubule dynamics. Tau misregulation is associated with a class of neurodegenerative diseases, known as tauopathies, including progressive supranuclear palsy, Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau are found in the C-terminal microtubule-binding domain. These mutations decrease microtubule-binding affinity and are proposed to reduce microtubule stability, leading to disease. N-terminal disease-associated mutations also exist, but the mechanistic details of their downstream effects are not as clear. Here, we investigate the effect of the progressive supranuclear palsy–associated N-terminal R5L mutation on Tau-mediated microtubule dynamics using an in vitro reconstituted system. We show that the R5L mutation does not alter Tau interactions with tubulin by fluorescence correlation spectroscopy. Using total internal reflection fluorescence microscopy, we determined that the R5L mutation has no effect on microtubule growth rate, catastrophe frequency, or rescue frequency. Rather, the R5L mutation increases microtubule shrinkage rate. We determine this is due to disruption of Tau patches, larger order Tau complexes known to form on the GDP-microtubule lattice. Altogether, these results provide insight into the role of Tau patches in mediating microtubule dynamics and suggesting a novel mechanism by which mutations in the N-terminal projection domain reduce microtubule stability.
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Affiliation(s)
- Alisa Cario
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405
| | - Sanjula P Wickramasinghe
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth Rhoades
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Christopher L Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405.
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20
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Barbolina MV. Targeting Microtubule-Associated Protein Tau in Chemotherapy-Resistant Models of High-Grade Serous Ovarian Carcinoma. Cancers (Basel) 2022; 14:4535. [PMID: 36139693 PMCID: PMC9496900 DOI: 10.3390/cancers14184535] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Relapsed, recurrent, chemotherapy-resistant high-grade serous ovarian carcinoma is the deadliest stage of this disease. Expression of microtubule-associated protein tau (tau) has been linked to resistance to paclitaxel treatment. Here, I used models of platinum-resistant and created models of platinum/paclitaxel-resistant high-grade serous ovarian carcinoma to examine the impact of reducing tau expression on cell survival and tumor burden in cell culture and xenograft and syngeneic models of the disease. Tau was overexpressed in platinum/paclitaxel-resistant models; expression of phosphoSer396 and phosphoThr181 species was also found. A treatment with leucomethylene blue reduced the levels of tau in treated cells, was cytotoxic in cell cultures, and efficiently reduced the tumor burden in xenograft models. Furthermore, a combination of leucomethylene blue and paclitaxel synergized in eliminating cancer cells in cell culture and xenograft models. These findings underscore the feasibility of targeting tau as a treatment option in terminal-stage high-grade serous ovarian cancer.
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Affiliation(s)
- Maria V Barbolina
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60091, USA
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21
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El Mammeri N, Dregni AJ, Duan P, Wang HK, Hong M. Microtubule-binding core of the tau protein. SCIENCE ADVANCES 2022; 8:eabo4459. [PMID: 35857846 PMCID: PMC9299549 DOI: 10.1126/sciadv.abo4459] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 06/07/2022] [Indexed: 05/15/2023]
Abstract
The protein tau associates with microtubules to maintain neuronal health. Posttranslational modifications of tau interfere with this binding, leading to tau aggregation in neurodegenerative disorders. Here, we use solid-state nuclear magnetic resonance (NMR) to investigate the structure of the microtubule-binding domain of tau. Wild-type tau that contains four microtubule-binding repeats and a pseudorepeat R' is studied. Complexed with taxol-stabilized microtubules, the immobilized residues exhibit well-resolved two-dimensional spectra that can be assigned to the amino-terminal region of R4 and the R' domain. When tau coassembles with tubulin to form unstable microtubules, the R' signals remain, whereas the R4 signals disappear, indicating that R' remains immobilized, whereas R4 becomes more mobile. Therefore, R' outcompetes the other four repeats to associate with microtubules. These NMR data, together with previous cryo-electron microscopy densities, indicate an extended conformation for microtubule-bound R'. R' contains the largest number of charged residues among all repeats, suggesting that charge-charge interaction drives tau-microtubule association.
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Affiliation(s)
- Nadia El Mammeri
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
| | | | - Pu Duan
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
| | - Harrison K. Wang
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139, USA
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22
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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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23
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Hochmair J, Exner C, Franck M, Dominguez‐Baquero A, Diez L, Brognaro H, Kraushar ML, Mielke T, Radbruch H, Kaniyappan S, Falke S, Mandelkow E, Betzel C, Wegmann S. Molecular crowding and RNA synergize to promote phase separation, microtubule interaction, and seeding of Tau condensates. EMBO J 2022; 41:e108882. [PMID: 35298090 PMCID: PMC9156969 DOI: 10.15252/embj.2021108882] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 02/09/2022] [Accepted: 02/15/2022] [Indexed: 11/09/2022] Open
Abstract
Biomolecular condensation of the neuronal microtubule-associated protein Tau (MAPT) can be induced by coacervation with polyanions like RNA, or by molecular crowding. Tau condensates have been linked to both functional microtubule binding and pathological aggregation in neurodegenerative diseases. We find that molecular crowding and coacervation with RNA, two conditions likely coexisting in the cytosol, synergize to enable Tau condensation at physiological buffer conditions and to produce condensates with a strong affinity to charged surfaces. During condensate-mediated microtubule polymerization, their synergy enhances bundling and spatial arrangement of microtubules. We further show that different Tau condensates efficiently induce pathological Tau aggregates in cells, including accumulations at the nuclear envelope that correlate with nucleocytoplasmic transport deficits. Fluorescent lifetime imaging reveals different molecular packing densities of Tau in cellular accumulations and a condensate-like density for nuclear-envelope Tau. These findings suggest that a complex interplay between interaction partners, post-translational modifications, and molecular crowding regulates the formation and function of Tau condensates. Conditions leading to prolonged existence of Tau condensates may induce the formation of seeding-competent Tau and lead to distinct cellular Tau accumulations.
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Affiliation(s)
- Janine Hochmair
- German Center for Neurodegenerative Diseases (DZNE)BerlinGermany
| | - Christian Exner
- Institute for Biochemistry and Molecular BiologyLaboratory for Structural Biology of Infection and InflammationUniversity of HamburgHamburgGermany
| | | | | | - Lisa Diez
- German Center for Neurodegenerative Diseases (DZNE)BerlinGermany
| | - Hévila Brognaro
- Institute for Biochemistry and Molecular BiologyLaboratory for Structural Biology of Infection and InflammationUniversity of HamburgHamburgGermany
| | | | - Thorsten Mielke
- Max Planck Institute for Molecular Genetics (MOLGEN)BerlinGermany
| | | | - Senthilvelrajan Kaniyappan
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
- Department of Neurodegenerative Diseases and Geriatric PsychiatryUniversity of BonnBonnGermany
| | - Sven Falke
- Institute for Biochemistry and Molecular BiologyLaboratory for Structural Biology of Infection and InflammationUniversity of HamburgHamburgGermany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
- Department of Neurodegenerative Diseases and Geriatric PsychiatryUniversity of BonnBonnGermany
| | - Christian Betzel
- Institute for Biochemistry and Molecular BiologyLaboratory for Structural Biology of Infection and InflammationUniversity of HamburgHamburgGermany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE)BerlinGermany
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Diez L, Kapinos LE, Hochmair J, Huebschmann S, Dominguez-Baquero A, Vogt A, Rankovic M, Zweckstetter M, Lim RYH, Wegmann S. Phosphorylation but Not Oligomerization Drives the Accumulation of Tau with Nucleoporin Nup98. Int J Mol Sci 2022; 23:3495. [PMID: 35408855 PMCID: PMC8998617 DOI: 10.3390/ijms23073495] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/19/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Tau is a neuronal protein that stabilizes axonal microtubules (MTs) in the central nervous system. In Alzheimer's disease (AD) and other tauopathies, phosphorylated Tau accumulates in intracellular aggregates, a pathological hallmark of these diseases. However, the chronological order of pathological changes in Tau prior to its cytosolic aggregation remains unresolved. These include its phosphorylation and detachment from MTs, mislocalization into the somatodendritic compartment, and oligomerization in the cytosol. Recently, we showed that Tau can interact with phenylalanine-glycine (FG)-rich nucleoporins (Nups), including Nup98, that form a diffusion barrier inside nuclear pore complexes (NPCs), leading to defects in nucleocytoplasmic transport. Here, we used surface plasmon resonance (SPR) and bio-layer interferometry (BLI) to investigate the molecular details of Tau:Nup98 interactions and determined how Tau phosphorylation and oligomerization impact the interactions. Importantly, phosphorylation, but not acetylation, strongly facilitates the accumulation of Tau with Nup98. Oligomerization, however, seems to inhibit Tau:Nup98 interactions, suggesting that Tau-FG Nup interactions occur prior to oligomerization. Overall, these results provide fundamental insights into the molecular mechanisms of Tau-FG Nup interactions within NPCs, which might explain how stress-and disease-associated posttranslational modifications (PTMs) may lead to Tau-induced nucleocytoplasmic transport (NCT) failure. Intervention strategies that could rescue Tau-induced NCT failure in AD and tauopathies will be further discussed.
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Affiliation(s)
- Lisa Diez
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Larisa E. Kapinos
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland; (L.E.K.); (R.Y.H.L.)
| | - Janine Hochmair
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Sabrina Huebschmann
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Alvaro Dominguez-Baquero
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Amelie Vogt
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Marija Rankovic
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Goettingen, Germany; (M.R.); (M.Z.)
| | - Markus Zweckstetter
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Goettingen, Germany; (M.R.); (M.Z.)
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Goettingen, Germany
| | - Roderick Y. H. Lim
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland; (L.E.K.); (R.Y.H.L.)
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
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The pathogenic R5L mutation disrupts formation of Tau complexes on the microtubule by altering local N-terminal structure. Proc Natl Acad Sci U S A 2022; 119:2114215119. [PMID: 35135879 PMCID: PMC8851524 DOI: 10.1073/pnas.2114215119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2021] [Indexed: 11/21/2022] Open
Abstract
The microtubule-associated protein (MAP) Tau is an intrinsically disordered protein (IDP) primarily expressed in axons, where it functions to regulate microtubule dynamics, modulate motor protein motility, and participate in signaling cascades. Tau misregulation and point mutations are linked to neurodegenerative diseases, including progressive supranuclear palsy (PSP), Pick's disease, and Alzheimer's disease. Many disease-associated mutations in Tau occur in the C-terminal microtubule-binding domain of the protein. Effects of C-terminal mutations in Tau have led to the widely accepted disease-state theory that missense mutations in Tau reduce microtubule-binding affinity or increase Tau propensity to aggregate. Here, we investigate the effect of an N-terminal arginine to leucine mutation at position 5 in Tau (R5L), associated with PSP, on Tau-microtubule interactions using an in vitro reconstituted system. Contrary to the canonical disease-state theory, we determine that the R5L mutation does not reduce Tau affinity for the microtubule using total internal reflection fluorescence microscopy. Rather, the R5L mutation decreases the ability of Tau to form larger-order complexes, or Tau patches, at high concentrations of Tau. Using NMR, we show that the R5L mutation results in a local structural change that reduces interactions of the projection domain in the presence of microtubules. Altogether, these results challenge both the current paradigm of how mutations in Tau lead to disease and the role of the projection domain in modulating Tau behavior on the microtubule surface.
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Kitoka K, Skrabana R, Gasparik N, Hritz J, Jaudzems K. NMR Studies of Tau Protein in Tauopathies. Front Mol Biosci 2021; 8:761227. [PMID: 34859051 PMCID: PMC8632555 DOI: 10.3389/fmolb.2021.761227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Tauopathies, including Alzheimer's disease (AD), are the most troublesome of all age-related chronic conditions, as there are no well-established disease-modifying therapies for their prevention and treatment. Spatio-temporal distribution of tau protein pathology correlates with cognitive decline and severity of the disease, therefore, tau protein has become an appealing target for therapy. Current knowledge of the pathological effects and significance of specific species in the tau aggregation pathway is incomplete although more and more structural and mechanistic insights are being gained using biophysical techniques. Here, we review the application of NMR to structural studies of various tau forms that appear in its aggregation process, focusing on results obtained from solid-state NMR. Furthermore, we discuss implications from these studies and their prospective contribution to the development of new tauopathy therapies.
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Affiliation(s)
- Kristine Kitoka
- Laboratory of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Rostislav Skrabana
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
- AXON Neuroscience R&D Services SE, Bratislava, Slovakia
| | - Norbert Gasparik
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
| | - Jozef Hritz
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Kristaps Jaudzems
- Laboratory of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
- Faculty of Chemistry, University of Latvia, Riga, Latvia
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Carroll T, Guha S, Nehrke K, Johnson GVW. Tau Post-Translational Modifications: Potentiators of Selective Vulnerability in Sporadic Alzheimer's Disease. BIOLOGY 2021; 10:1047. [PMID: 34681146 PMCID: PMC8533264 DOI: 10.3390/biology10101047] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 12/14/2022]
Abstract
Sporadic Alzheimer's Disease (AD) is the most common form of dementia, and its severity is characterized by the progressive formation of tau neurofibrillary tangles along a well-described path through the brain. This spatial progression provides the basis for Braak staging of the pathological progression for AD. Tau protein is a necessary component of AD pathology, and recent studies have found that soluble tau species with selectively, but not extensively, modified epitopes accumulate along the path of disease progression before AD-associated insoluble aggregates form. As such, modified tau may represent a key cellular stressing agent that potentiates selective vulnerability in susceptible neurons during AD progression. Specifically, studies have found that tau phosphorylated at sites such as T181, T231, and S396 may initiate early pathological changes in tau by disrupting proper tau localization, initiating tau oligomerization, and facilitating tau accumulation and extracellular export. Thus, this review elucidates potential mechanisms through which tau post-translational modifications (PTMs) may simultaneously serve as key modulators of the spatial progression observed in AD development and as key instigators of early pathology related to neurodegeneration-relevant cellular dysfunctions.
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Affiliation(s)
- Trae Carroll
- Department of Pathology, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Sanjib Guha
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Keith Nehrke
- Department of Medicine, Nephrology Division, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
| | - Gail V. W. Johnson
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center (URMC), Rochester, NY 14642, USA;
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Target-binding behavior of IDPs via pre-structured motifs. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 183:187-247. [PMID: 34656329 DOI: 10.1016/bs.pmbts.2021.07.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pre-Structured Motifs (PreSMos) are transient secondary structures observed in many intrinsically disordered proteins (IDPs) and serve as protein target-binding hot spots. The prefix "pre" highlights that PreSMos exist a priori in the target-unbound state of IDPs as the active pockets of globular proteins pre-exist before target binding. Therefore, a PreSMo is an "active site" of an IDP; it is not a spatial pocket, but rather a secondary structural motif. The classical and perhaps the most effective approach to understand the function of a protein has been to determine and investigate its structure. Ironically or by definition IDPs do not possess structure (here structure refers to tertiary structure only). Are IDPs then entirely structureless? The PreSMos provide us with an atomic-resolution answer to this question. For target binding, IDPs do not rely on the spatial pockets afforded by tertiary or higher structures. Instead, they utilize the PreSMos possessing particular conformations that highly presage the target-bound conformations. PreSMos are recognized or captured by targets via conformational selection (CS) before their conformations eventually become stabilized via structural induction into more ordered bound structures. Using PreSMos, a number of, if not all, IDPs can bind targets following a sequential pathway of CS followed by an induced fit (IF). This chapter presents several important PreSMos implicated in cancers, neurodegenerative diseases, and other diseases along with discussions on their conformational details that mediate target binding, a structural rationale for unstructured proteins.
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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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Khan MI, Gilpin K, Hasan F, Mahmud KAHA, Adnan A. Effect of Strain Rate on Single Tau, Dimerized Tau and Tau-Microtubule Interface: A Molecular Dynamics Simulation Study. Biomolecules 2021; 11:1308. [PMID: 34572521 PMCID: PMC8472149 DOI: 10.3390/biom11091308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 01/24/2023] Open
Abstract
Microtubule-associated protein (MAP) tau is a cross-linking molecule that provides structural stability to axonal microtubules (MT). It is considered a potential biomarker for Alzheimer's disease (AD), dementia, and other neurological disorders. It is also a signature protein for Traumatic Brain Injury (TBI) assessment. In the case of TBI, extreme dynamic mechanical energies can be felt by the axonal cytoskeletal members. As such, fundamental understandings of the responses of single tau protein, polymerized tau protein, and tau-microtubule interfaces under high-rate mechanical forces are important. This study attempts to determine the high-strain rate mechanical behavior of single tau, dimerized tau, and tau-MT interface using molecular dynamics (MD) simulation. The results show that a single tau protein is a highly stretchable soft polymer. During deformation, first, it significantly unfolds against van der Waals and electrostatic bonds. Then it stretches against strong covalent bonds. We found that tau acts as a viscoelastic material, and its stiffness increases with the strain rate. The unfolding stiffness can be ~50-500 MPa, while pure stretching stiffness can be >2 GPa. The dimerized tau model exhibits similar behavior under similar strain rates, and tau sliding from another tau is not observed until it is stretched to >7 times of original length, depending on the strain rate. The tau-MT interface simulations show that very high strain and strain rates are required to separate tau from MT suggesting Tau-MT bonding is stronger than MT subunit bonding between themselves. The dimerized tau-MT interface simulations suggest that tau-tau bonding is stronger than tau-MT bonding. In summary, this study focuses on the structural response of individual cytoskeletal components, namely microtubule (MT) and tau protein. Furthermore, we consider not only the individual response of a component, but also their interaction with each other (such as tau with tau or tau with MT). This study will eventually pave the way to build a bottom-up multiscale brain model and analyze TBI more comprehensively.
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Affiliation(s)
- Md Ishak Khan
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX 76019, USA; (M.I.K.); (F.H.); (K.A.H.A.M.)
| | - Kathleen Gilpin
- Academic Partnership and Engagement Experiment (APEX), Wright State Applied Research Corporation, Beavercreek, OH 45431, USA;
| | - Fuad Hasan
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX 76019, USA; (M.I.K.); (F.H.); (K.A.H.A.M.)
| | - Khandakar Abu Hasan Al Mahmud
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX 76019, USA; (M.I.K.); (F.H.); (K.A.H.A.M.)
| | - Ashfaq Adnan
- Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Arlington, TX 76019, USA; (M.I.K.); (F.H.); (K.A.H.A.M.)
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Grubisha MJ, Sun X, MacDonald ML, Garver M, Sun Z, Paris KA, Patel DS, DeGiosio RA, Lewis DA, Yates NA, Camacho C, Homanics GE, Ding Y, Sweet RA. MAP2 is differentially phosphorylated in schizophrenia, altering its function. Mol Psychiatry 2021; 26:5371-5388. [PMID: 33526823 PMCID: PMC8325721 DOI: 10.1038/s41380-021-01034-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 01/04/2021] [Accepted: 01/15/2021] [Indexed: 01/30/2023]
Abstract
Schizophrenia (Sz) is a highly polygenic disorder, with common, rare, and structural variants each contributing only a small fraction of overall disease risk. Thus, there is a need to identify downstream points of convergence that can be targeted with therapeutics. Reduction of microtubule-associated protein 2 (MAP2) immunoreactivity (MAP2-IR) is present in individuals with Sz, despite no change in MAP2 protein levels. MAP2 is phosphorylated downstream of multiple receptors and kinases identified as Sz risk genes, altering its immunoreactivity and function. Using an unbiased phosphoproteomics approach, we quantified 18 MAP2 phosphopeptides, 9 of which were significantly altered in Sz subjects. Network analysis grouped MAP2 phosphopeptides into three modules, each with a distinct relationship to dendritic spine loss, synaptic protein levels, and clinical function in Sz subjects. We then investigated the most hyperphosphorylated site in Sz, phosphoserine1782 (pS1782). Computational modeling predicted phosphorylation of S1782 reduces binding of MAP2 to microtubules, which was confirmed experimentally. We generated a transgenic mouse containing a phosphomimetic mutation at S1782 (S1782E) and found reductions in basilar dendritic length and complexity along with reduced spine density. Because only a limited number of MAP2 interacting proteins have been previously identified, we combined co-immunoprecipitation with mass spectrometry to characterize the MAP2 interactome in mouse brain. The MAP2 interactome was enriched for proteins involved in protein translation. These associations were shown to be functional as overexpression of wild type and phosphomimetic MAP2 reduced protein synthesis in vitro. Finally, we found that Sz subjects with low MAP2-IR had reductions in the levels of synaptic proteins relative to nonpsychiatric control (NPC) subjects and to Sz subjects with normal and MAP2-IR, and this same pattern was recapitulated in S1782E mice. These findings suggest a new conceptual framework for Sz-that a large proportion of individuals have a "MAP2opathy"-in which MAP function is altered by phosphorylation, leading to impairments of neuronal structure, synaptic protein synthesis, and function.
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Affiliation(s)
- M J Grubisha
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - X Sun
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Tsinghua MD Program, School of Medicine, Tsinghua University, Beijing, China
| | - M L MacDonald
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Garver
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Z Sun
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - K A Paris
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - D S Patel
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - R A DeGiosio
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - D A Lewis
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - N A Yates
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
- Biomedical Mass Spectrometry Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - C Camacho
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - G E Homanics
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology & Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Y Ding
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - R A Sweet
- Department of Psychiatry, Translational Neuroscience Program, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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32
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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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Irwin R, Faust O, Petrovic I, Wolf SG, Hofmann H, Rosenzweig R. Hsp40s play complementary roles in the prevention of tau amyloid formation. eLife 2021; 10:69601. [PMID: 34369377 PMCID: PMC8437434 DOI: 10.7554/elife.69601] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/08/2021] [Indexed: 11/21/2022] Open
Abstract
The microtubule-associated protein, tau, is the major subunit of neurofibrillary tangles associated with neurodegenerative conditions, such as Alzheimer's disease. In the cell, however, tau aggregation can be prevented by a class of proteins known as molecular chaperones. While numerous chaperones are known to interact with tau, though, little is known regarding the mechanisms by which these prevent tau aggregation. Here, we describe the effects of ATP-independent Hsp40 chaperones, DNAJA2 and DNAJB1, on tau amyloid-fiber formation and compare these to the small heat shock protein HSPB1. We find that the chaperones play complementary roles, with each preventing tau aggregation differently and interacting with distinct sets of tau species. Whereas HSPB1 only binds tau monomers, DNAJB1 and DNAJA2 recognize aggregation-prone conformers and even mature fibers. In addition, we find that both Hsp40s bind tau seeds and fibers via their C-terminal domain II (CTDII), with DNAJA2 being further capable of recognizing tau monomers by a second, distinct site in CTDI. These results lay out the mechanisms by which the diverse members of the Hsp40 family counteract the formation and propagation of toxic tau aggregates and highlight the fact that chaperones from different families/classes play distinct, yet complementary roles in preventing pathological protein aggregation. Several neurological conditions, such as Alzheimer’s and Parkinson’s disease, are characterized by the build-up of protein clumps known as aggregates. In the case of Alzheimer’s disease, a key protein, called tau, aggregates to form fibers that are harmful to neuronal cells in the brain. One of the ways our cells can prevent this from occurring is through the action of proteins known as molecular chaperones, which can bind to tau proteins and prevent them from sticking together. Tau can take on many forms. For example, a single tau protein on its own, known as a monomer, is unstructured. In patients with Alzheimer’s, these monomers join together into small clusters, known as seeds, that rapidly aggregate and accumulate into rigid, structured fibers. One chaperone, HSPB1, is known to bind to tau monomers and prevent them from being incorporated into fibers. Recently, another group of chaperones, called J-domain proteins, was also found to interact with tau. However, it was unclear how these chaperones prevent aggregation and whether they bind to tau in a similar manner as HSPB1. To help answer this question, Irwin, Faust et al. studied the effect of two J-domain proteins, as well as the chaperone HSBP1, on tau aggregation. This revealed that, unlike HSBP1, the two J-domain proteins can bind to multiple forms of tau, including when it has already aggregated in to seeds and fibers. This suggests that these chaperones can stop the accumulation of fibers at several different stages of the aggregation process. Further experiments examining which sections of the J-domain proteins bind to tau, showed that both attach to fibers via the same region. However, the two J-domain proteins are not identical in their interaction with tau. While one of them uses a distinct region to bind to tau monomers, the other does not bind to single tau proteins at all. These results demonstrate how different cellular chaperones can complement one another in order to inhibit harmful protein aggregation. Further studies will be needed to understand the full role of J-domain proteins in preventing tau from accumulating into fibers, as well as their potential as drug targets for developing new treatments.
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Affiliation(s)
- Rose Irwin
- Weizmann Institute of Science, Rehovot, Israel
| | - Ofrah Faust
- Weizmann Institute of Science, Rehovot, Israel
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Xia Y, Prokop S, Giasson BI. "Don't Phos Over Tau": recent developments in clinical biomarkers and therapies targeting tau phosphorylation in Alzheimer's disease and other tauopathies. Mol Neurodegener 2021; 16:37. [PMID: 34090488 PMCID: PMC8180161 DOI: 10.1186/s13024-021-00460-5] [Citation(s) in RCA: 102] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/26/2021] [Indexed: 12/11/2022] Open
Abstract
Phosphorylation is one of the most prevalent post-translational modifications found in aggregated tau isolated from Alzheimer’s disease (AD) patient brains. In tauopathies like AD, increased phosphorylation or hyperphosphorylation can contribute to microtubule dysfunction and is associated with tau aggregation. In this review, we provide an overview of the structure and functions of tau protein as well as the physiologic roles of tau phosphorylation. We also extensively survey tau phosphorylation sites identified in brain tissue and cerebrospinal fluid from AD patients compared to age-matched healthy controls, which may serve as disease-specific biomarkers. Recently, new assays have been developed to measure minute amounts of specific forms of phosphorylated tau in both cerebrospinal fluid and plasma, which could potentially be useful for aiding clinical diagnosis and monitoring disease progression. Additionally, multiple therapies targeting phosphorylated tau are in various stages of clinical trials including kinase inhibitors, phosphatase activators, and tau immunotherapy. With promising early results, therapies that target phosphorylated tau could be useful at slowing tau hyperphosphorylation and aggregation in AD and other tauopathies.
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Affiliation(s)
- Yuxing Xia
- Department of Neuroscience, College of Medicine, University of Florida, BMS J483/CTRND, 1275 Center Drive, Gainesville, FL, 32610, USA.,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA
| | - Stefan Prokop
- Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.,Department of Pathology, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.,McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA
| | - Benoit I Giasson
- Department of Neuroscience, College of Medicine, University of Florida, BMS J483/CTRND, 1275 Center Drive, Gainesville, FL, 32610, USA. .,Center for Translational Research in Neurodegenerative Disease, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA. .,McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, Florida, 32610, USA.
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Mah D, Zhao J, Liu X, Zhang F, Liu J, Wang L, Linhardt R, Wang C. The Sulfation Code of Tauopathies: Heparan Sulfate Proteoglycans in the Prion Like Spread of Tau Pathology. Front Mol Biosci 2021; 8:671458. [PMID: 34095227 PMCID: PMC8173255 DOI: 10.3389/fmolb.2021.671458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
Tauopathies are a heterogenous family of progressive neurodegenerative diseases defined by the appearance of proteinaceous lesions within the brain composed of abnormally folded species of Microtubule Associated Protein Tau (tau). Alzheimer's Disease (AD), the most common tauopathy, is the leading cause of cognitive decline among the elderly and is responsible for more than half of all cases of senile dementia worldwide. The characteristic pathology of many tauopathies-AD included-presents as Neurofibrillary Tangles (NFTs), insoluble inclusions found within the neurons of the central nervous system composed primarily of tau protein arranged into Paired Helical Fibrils (PHFs). The spatial extent of this pathology evolves in a remarkably consistent pattern over the course of disease progression. Among the leading hypotheses which seek to explain the stereotypical progression of tauopathies is the prion model, which proposes that the spread of tau pathology is mediated by the transmission of self-propagating tau conformers between cells in a fashion analogous to the mechanism of communicable prion diseases. Protein-glycan interactions between tau and Heparan Sulfate Proteoglycans (HSPGs) have been implicated as a key facilitator in each stage of the prion-like propagation of tau pathology, from the initial secretion of intracellular tau protein into the extracellular matrix, to the uptake of pathogenic tau seeds by cells, and the self-assembly of tau into higher order aggregates. In this review we outline the biochemical basis of the tau-HS interaction and discuss our current understanding of the mechanisms by which these interactions contribute to the propagation of tau pathology in tauopathies, with a particular focus on AD.
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Affiliation(s)
- Dylan Mah
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Jing Zhao
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Xinyue Liu
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Harvard Medical School, Harvard University, Boston, MA, United States
| | - Fuming Zhang
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Jian Liu
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lianchun Wang
- Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Robert Linhardt
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Chunyu Wang
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
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Dixit H, Kumar C S, Chaudhary R, Thaker D, Gadewal N, Dasgupta D. Role of Phosphorylation and Hyperphosphorylation of Tau in Its Interaction with βα Dimeric Tubulin Studied from a Bioinformatics Perspective. Avicenna J Med Biotechnol 2021; 13:24-34. [PMID: 33680370 PMCID: PMC7903436 DOI: 10.18502/ajmb.v13i1.4579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background: Tau is a disordered Microtubule Associated Protein (MAP) which prefers to bind and stabilize microtubules. Phosphorylation of tau in particular enhances tautubulin interaction which otherwise detaches from tubulin during hyperphosphorylation. The reason behind their destabilization, detachment and the role of β subunit (from microtubule) and the projection domain (Tau) in microtubule stability remains elusive till date. Thus, a complete 3D structural investigation of tau protein is much needed to address these queries as the existing crystal structures are in fragments and quite limited. Methods: In this study, the modelled human tau protein was subjected to phosphorylation and hyperphosphorylation which were later considered for docking with micro-tubules (βα subunits-inter dimer) and vinblastine. Results: Phosphorylated tau protein interacts with both α- and β subunits. But stronger bonding was with α- compared to β subunits. Regarding β subunit, proline rich loop and projection domain actively participated in tau binding. Interestingly, hyperphosphorylation of tau increases MAP domain flexibility which ultimately results in tau detachment, the main reason behind tangle formation in Alzheimer’s disease. Conclusion: This study being the first of its kind emphasizes the role of projection domain and proline rich region of β-subunit in stabilizing the tau-tubulin interaction and also the effect of hyperphosphorylation in protein-protein and protein-drug binding.
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Affiliation(s)
- Hrushikesh Dixit
- Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
| | - Selvaa Kumar C
- Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
| | - Ruchi Chaudhary
- Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
| | - Divya Thaker
- Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
| | - Nikhil Gadewal
- Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Kharghar, Navi Mumbai, India
| | - Debjani Dasgupta
- Faculty of Biotechnology and Bioinformatics, D.Y. Patil Deemed to be University, CBD Belapur, Navi Mumbai, India
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Siegert A, Rankovic M, Favretto F, Ukmar-Godec T, Strohäker T, Becker S, Zweckstetter M. Interplay between tau and α-synuclein liquid-liquid phase separation. Protein Sci 2021; 30:1326-1336. [PMID: 33452693 PMCID: PMC8197422 DOI: 10.1002/pro.4025] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/07/2023]
Abstract
In Parkinson's disease with dementia, up to 50% of patients develop a high number of tau‐containing neurofibrillary tangles. Tau‐based pathologies may thus act synergistically with the α‐synuclein pathology to confer a worse prognosis. A better understanding of the relationship between the two distinct pathologies is therefore required. Liquid–liquid phase separation (LLPS) of proteins has recently been shown to be important for protein aggregation involved in amyotrophic lateral sclerosis, whereas tau phase separation has been linked to Alzheimer's disease. We therefore investigated the interaction of α‐synuclein with tau and its consequences on tau LLPS. We find α‐synuclein to have a low propensity for both, self‐coacervation and RNA‐mediated LLPS at pH 7.4. However, full‐length but not carboxy‐terminally truncated α‐synuclein efficiently partitions into tau/RNA droplets. We further demonstrate that Cdk2‐phosphorylation promotes the concentration of tau into RNA‐induced droplets, but at the same time decreases the amount of α‐synuclein inside the droplets. NMR spectroscopy reveals that the interaction of the carboxy‐terminal domain of α‐synuclein with the proline‐rich region P2 of tau is required for the recruitment of α‐synuclein into tau droplets. The combined data suggest that the concentration of α‐synuclein into tau‐associated condensates can contribute to synergistic aSyn/tau pathologies.
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Affiliation(s)
- Anna Siegert
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Marija Rankovic
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Filippo Favretto
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Tina Ukmar-Godec
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Timo Strohäker
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Stefan Becker
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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38
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Recent studies of atomic-resolution structures of tau protein and structure-based inhibitors. QUANTITATIVE BIOLOGY 2021. [DOI: 10.15302/j-qb-021-0271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Savastano A, Jaipuria G, Andreas L, Mandelkow E, Zweckstetter M. Solid-state NMR investigation of the involvement of the P2 region in tau amyloid fibrils. Sci Rep 2020; 10:21210. [PMID: 33273615 PMCID: PMC7712923 DOI: 10.1038/s41598-020-78161-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/20/2020] [Indexed: 11/08/2022] Open
Abstract
The aggregation of hyperphosphorylated tau into amyloid fibrils is closely linked to the progression of Alzheimer's disease. To gain insight into the link between amyloid structure and disease, the three-dimensional structure of tau fibrils has been studied using solid-state NMR (ssNMR) and cryogenic electron microscopy (cryo-EM). The proline-rich region of tau remains poorly defined in the context of tau amyloid structures, despite the clustering of several phosphorylation sites, which have been associated with Alzheimer's disease. In order to gain insight into the contribution of the proline-rich region P2 of tau to amyloid fibrils, we studied in vitro aggregated amyloid fibrils of tau constructs, which contain both the proline-rich region P2 and the pseudo-repeats. Using ssNMR we show that the sequence [Formula: see text], the most hydrophobic patch within the P2 region, loses its flexibility upon formation of amyloid fibrils. The data suggest a contribution of the P2 region to tau amyloid fibril formation, which might account for some of the unassigned electron density in cryo-EM studies of tau fibrils and could be modulated by tau phosphorylation at the disease-associated AT180 epitope T231/S235.
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Affiliation(s)
- Adriana Savastano
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Garima Jaipuria
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Loren Andreas
- Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, 53127, Bonn, Germany
- CAESAR Research Center, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.
- Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.
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40
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Abstract
Tau, a microtubule-associated protein, plays a critical role in the pathophysiology of neurons. However, whether tau protein is expressed in smooth muscle cells is unknown. Thus, we tested the hypothesis that tau protein is expressed in the primary cultures of smooth muscle cells. Here, we report that tau protein is expressed and constitutively phosphorylated at threonine 181 in various smooth muscle cell types, including human pulmonary artery smooth muscle cells, bronchial airway smooth muscle cells, and cerebral artery smooth muscle cells. Immunofluorescence staining revealed that phosphorylated tau at threonine 181 is more organized in the cell than is total tau protein. A protein phosphatase inhibitor, calyculin A, induced the formation of higher molecular weight species of phosphorylated tau, as visualized by Western blotting, indicating the occurrence of tau aggregation. Immunofluorescence analysis also showed that calyculin A caused the aggregation of phosphorylated tau and disrupted the cytoskeletal organization. These results demonstrate the existence of tau protein in smooth muscle cells, and that smooth muscle tau is susceptible to protein phosphorylation and aggregation. Lung smooth muscle tau may therefore play an important role in pulmonary pathophysiology.
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Alyenbaawi H, Allison WT, Mok SA. Prion-Like Propagation Mechanisms in Tauopathies and Traumatic Brain Injury: Challenges and Prospects. Biomolecules 2020; 10:E1487. [PMID: 33121065 PMCID: PMC7692808 DOI: 10.3390/biom10111487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/23/2022] Open
Abstract
The accumulation of tau protein in the form of filamentous aggregates is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). These dementias share traumatic brain injury (TBI) as a prominent risk factor. Tau aggregates can transfer between cells and tissues in a "prion-like" manner, where they initiate the templated misfolding of normal tau molecules. This enables the spread of tau pathology to distinct parts of the brain. The evidence that tauopathies spread via prion-like mechanisms is considerable, but work detailing the mechanisms of spread has mostly used in vitro platforms that cannot fully reveal the tissue-level vectors or etiology of progression. We review these issues and then briefly use TBI and CTE as a case study to illustrate aspects of tauopathy that warrant further attention in vivo. These include seizures and sleep/wake disturbances, emphasizing the urgent need for improved animal models. Dissecting these mechanisms of tauopathy progression continues to provide fresh inspiration for the design of diagnostic and therapeutic approaches.
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Affiliation(s)
- Hadeel Alyenbaawi
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Medical Laboratories, Majmaah University, Majmaah 11952, Saudi Arabia
| | - W. Ted Allison
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Sue-Ann Mok
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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Katsinelos T, Doulberis M, Polyzos SA, Papaefthymiou A, Katsinelos P, Kountouras J. Molecular Links Between Alzheimer's Disease and Gastrointestinal Microbiota: Emphasis on Helicobacter pylori Infection Involvement. Curr Mol Med 2020; 20:3-12. [PMID: 31530263 DOI: 10.2174/1566524019666190917125917] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/09/2019] [Accepted: 09/29/2019] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease and the main form of dementia, characterized by progressive cognitive decline and detrimental consequences in both personal-family and global level. Within this narrative review, we provide recent molecular aspects of Tau, a microtubule AD-associated protein, as well as amyloid beta, involved in AD pathophysiology. Moreover, we provide additional emerging data from basic research as well as clinical studies indicating an implicating role of gastrointestinal microbiota (GI-M), including Helicobacter pylori infection (Hp-I), in AD pathophysiology. Likewise, we identified through a molecular prism the current evidence of AD pathogenesis as well as its linkage with GI-M and emphasizing the role of Hp-I. All in all, additional large-scale studies are required for the further clarification of AD pathophysiology and its connection with GI-M and Hp-I, so as novel therapies on molecular basis become available.
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Affiliation(s)
- Taxiarchis Katsinelos
- UK Dementia Research Institute at the University of Cambridge, Hills Road, Cambridge, CB2 0AH, United Kingdom
| | - Michael Doulberis
- Department of Gastroenterology and Hepatology, University of Zurich, Zurich 8091, Switzerland.,Department of Internal Medicine, Second Medical Clinic, Ippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki 54642, Macedonia, Greece
| | - Stergios A Polyzos
- Department of Internal Medicine, Second Medical Clinic, Ippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki 54642, Macedonia, Greece.,First Department of Pharmacology Medical School, Aristotle University of Thessaloniki, Thessaloniki 54124, Macedonia, Greece
| | - Apostolis Papaefthymiou
- Department of Internal Medicine, Second Medical Clinic, Ippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki 54642, Macedonia, Greece.,Department of Gastroenterology, 401 General Military Hospital of Athens, Athens 11525, Greece
| | - Panagiotis Katsinelos
- Department of Internal Medicine, Second Medical Clinic, Ippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki 54642, Macedonia, Greece
| | - Jannis Kountouras
- Department of Internal Medicine, Second Medical Clinic, Ippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki 54642, Macedonia, Greece
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Inflammation: major denominator of obesity, Type 2 diabetes and Alzheimer's disease-like pathology? Clin Sci (Lond) 2020; 134:547-570. [PMID: 32167154 DOI: 10.1042/cs20191313] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/08/2023]
Abstract
Adipose tissue is an active metabolic organ that contributes to processes such as energy storage and utilization and to the production of a number of metabolic agents, such as adipokines, which play a role in inflammation. In this review, we try to elucidate the connections between peripheral inflammation at obesity and Type 2 diabetes and the central inflammatory process. Multiple lines of evidence highlight the importance of peripheral inflammation and its link to neuroinflammation, which can lead to neurodegenerative diseases such as dementia, Alzheimer's disease (AD) and Parkinson's disease. In addition to the accumulation of misfolded amyloid beta (Aβ) peptide and the formation of the neurofibrillary tangles of hyperphosphorylated tau protein in the brain, activated microglia and reactive astrocytes are the main indicators of AD progression. They were found close to Aβ plaques in the brains of both AD patients and rodent models of Alzheimer's disease-like pathology. Cytokines are key players in pro- and anti-inflammatory processes and are also produced by microglia and astrocytes. The interplay of seemingly unrelated pathways between the periphery and the brain could, in fact, have a common denominator, with inflammation in general being a key factor affecting neuronal processes in the brain. An increased amount of white adipose tissue throughout the body seems to be an important player in pro-inflammatory processes. Nevertheless, other important factors should be studied to elucidate the pathological processes of and the relationship among obesity, Type 2 diabetes and neurodegenerative diseases.
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Tau and Alpha Synuclein Synergistic Effect in Neurodegenerative Diseases: When the Periphery Is the Core. Int J Mol Sci 2020; 21:ijms21145030. [PMID: 32708732 PMCID: PMC7404325 DOI: 10.3390/ijms21145030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 02/08/2023] Open
Abstract
In neuronal cells, tau is a microtubule-associated protein placed in axons and alpha synuclein is enriched at presynaptic terminals. They display a propensity to form pathologic aggregates, which are considered the underlying cause of Alzheimer's and Parkinson's diseases. Their functional impairment induces loss of axonal transport, synaptic and mitochondrial disarray, leading to a "dying back" pattern of degeneration, which starts at the periphery of cells. In addition, pathologic spreading of alpha-synuclein from the peripheral nervous system to the brain through anatomical connectivity has been demonstrated for Parkinson's disease. Thus, examination of the extent and types of tau and alpha-synuclein in peripheral tissues and their relation to brain neurodegenerative diseases is of relevance since it may provide insights into patterns of protein aggregation and neurodegeneration. Moreover, peripheral nervous tissues are easily accessible in-vivo and can play a relevant role in the early diagnosis of these conditions. Up-to-date investigations of tau species in peripheral tissues are scant and have mainly been restricted to rodents, whereas, more evidence is available on alpha synuclein in peripheral tissues. Here we aim to review the literature on the functional role of tau and alpha synuclein in physiological conditions and disease at the axonal level, their distribution in peripheral tissues, and discuss possible commonalities/diversities as well as their interaction in proteinopathies.
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Rane JS, Kumari A, Panda D. The Acetyl Mimicking Mutation, K274Q in Tau, Enhances the Metal Binding Affinity of Tau and Reduces the Ability of Tau to Protect DNA. ACS Chem Neurosci 2020; 11:291-303. [PMID: 31886644 DOI: 10.1021/acschemneuro.9b00455] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The aggregation of tau, a microtubule-associated protein, is known to play an important role in several neurological disorders including Alzheimer's disease. Alzheimer's disease is considered to be associated with the dyshomeostasis of metal ions such as aluminum, zinc, copper, and ferric ions. Tau is predominately acetylated at the K274 residue in Alzheimer's disease, and the acetylation of the K274 residue is thought to be linked with dementia. Using acetyl mimicking K274Q mutation in tau, we have examined the effects of the acetylation at K274 residue of tau on the interactions of tau with metal ions and also on the ability of tau to protect DNA from the heat and other stressors. We found that Zn2+ and Al3+ increased the liquid-liquid phase separation of tau, an initial stage of tau aggregation. Further, Zn2+ and Al3+ considerably reduced the critical concentration for the phase separation of K274Q tau. Using far-UV circular dichroism and fluorescence spectroscopy, we provide evidence suggesting that the binding of Zn2+ and Al3+ induces conformational changes in tau. The K274Q mutation enhanced the binding affinity of tau for Zn2+, Al3+, Cu2+, and Fe3+ ions. In addition, Zn2+, Al3+, Cu2+, and Fe3+ significantly enhanced the aggregation propensity of K274Q tau in comparison to tau. Interestingly, tau binds to DNA with a higher affinity than K274Q tau. Tau protects DNA from the DNase treatment in vitro as well as from the heat stress in neuroblastoma cells more efficiently than K274Q tau. The results indicated that the acetylation of K274 residue of tau may increase metal ion-induced toxicity and diminish the ability of tau to protect DNA.
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Affiliation(s)
- Jitendra Subhash Rane
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Anuradha Kumari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Dulal Panda
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
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46
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Fung HYJ, McKibben KM, Ramirez J, Gupta K, Rhoades E. Structural Characterization of Tau in Fuzzy Tau:Tubulin Complexes. Structure 2020; 28:378-384.e4. [PMID: 31995742 DOI: 10.1016/j.str.2020.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 11/21/2019] [Accepted: 01/07/2020] [Indexed: 02/02/2023]
Abstract
Tau is a neuronal microtubule (MT)-associated protein of significant interest due to its association with several neurodegenerative disorders. Tau's intrinsic disorder and the dynamic nature of its interactions with tubulin and MTs make its structural characterization challenging. Here, we use an environmentally sensitive fluorophore as a site-specific probe of tau bound to soluble tubulin. Comparison of our results with a recently published tau:MT cryoelectron microscopy model reveals structural similarities between tubulin- and MT-bound tau. Analysis of residues across the repeat regions reveals a hierarchy in tubulin occupancy, which may be relevant to tau's ability to differentiate between tubulin and MTs. As binding to soluble tubulin is a critical first step in MT polymerization, our characterization of the structural features of tau in dynamic, fuzzy tau:tubulin assemblies advances our understanding of how tau functions in the cell and how function may be disrupted in disease.
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Affiliation(s)
- Ho Yee Joyce Fung
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kristen M McKibben
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer Ramirez
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kushol Gupta
- Department of Biochemistry and Biophysics, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA 19104, USA.
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47
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Haldar B, Hamilton CL, Solodushko V, Abney KA, Alexeyev M, Honkanen RE, Scammell JG, Cioffi DL. S100A6 is a positive regulator of PPP5C-FKBP51-dependent regulation of endothelial calcium signaling. FASEB J 2020; 34:3179-3196. [PMID: 31916625 DOI: 10.1096/fj.201901777r] [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] [Received: 07/15/2019] [Revised: 10/18/2019] [Accepted: 12/19/2019] [Indexed: 11/11/2022]
Abstract
ISOC is a cation current permeating the ISOC channel. In pulmonary endothelial cells, ISOC activation leads to formation of inter-endothelial cell gaps and barrier disruption. The immunophilin FK506-binding protein 51 (FKBP51), in conjunction with the serine/threonine protein phosphatase 5C (PPP5C), inhibits ISOC . Free PPP5C assumes an autoinhibitory state, which has low "basal" catalytic activity. Several S100 protein family members bind PPP5C increasing PPP5C catalytic activity in vitro. One of these family members, S100A6, exhibits a calcium-dependent translocation to the plasma membrane. The goal of this study was to determine whether S100A6 activates PPP5C in pulmonary endothelial cells and contributes to ISOC inhibition by the PPP5C-FKBP51 axis. We observed that S100A6 activates PPP5C to dephosphorylate tau T231. Following ISOC activation, cytosolic S100A6 translocates to the plasma membrane and interacts with the TRPC4 subunit of the ISOC channel. Global calcium entry and ISOC are decreased by S100A6 in a PPP5C-dependent manner and by FKBP51 in a S100A6-dependent manner. Further, calcium entry-induced endothelial barrier disruption is decreased by S100A6 dependent upon PPP5C, and by FKBP51 dependent upon S100A6. Overall, these data reveal that S100A6 plays a key role in the PPP5C-FKBP51 axis to inhibit ISOC and protect the endothelial barrier against calcium entry-induced disruption.
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Affiliation(s)
- Barnita Haldar
- Departments of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, University of South Alabama, Mobile, AL, USA
| | - Caleb L Hamilton
- Department of Anatomy and Molecular Medicine, Alabama College of Osteopathic Medicine, Dothan, AL, USA
| | - Viktoriya Solodushko
- Departments of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA
| | - Kevin A Abney
- Departments of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA
| | - Mikhail Alexeyev
- Center for Lung Biology, University of South Alabama, Mobile, AL, USA.,Physiology and Cell Biology, University of South Alabama, Mobile, AL, USA
| | - Richard E Honkanen
- Departments of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA
| | | | - Donna L Cioffi
- Departments of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL, USA.,Center for Lung Biology, University of South Alabama, Mobile, AL, USA
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48
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McKibben KM, Rhoades E. Independent tubulin binding and polymerization by the proline-rich region of Tau is regulated by Tau's N-terminal domain. J Biol Chem 2019; 294:19381-19394. [PMID: 31699899 DOI: 10.1074/jbc.ra119.010172] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/06/2019] [Indexed: 11/06/2022] Open
Abstract
Tau is an intrinsically disordered, microtubule-associated protein that has a role in regulating microtubule dynamics. Despite intensive research, the molecular mechanisms of Tau-mediated microtubule polymerization are poorly understood. Here we used single-molecule fluorescence to investigate the role of Tau's N-terminal domain (NTD) and proline-rich region (PRR) in regulating interactions of Tau with soluble tubulin. We assayed both full-length Tau isoforms and truncated variants for their ability to bind soluble tubulin and stimulate microtubule polymerization. We found that Tau's PRR is an independent tubulin-binding domain that has tubulin polymerization capacity. In contrast to the relatively weak interactions with tubulin mediated by sites distributed throughout Tau's microtubule-binding region (MTBR), resulting in heterogeneous Tau: tubulin complexes, the PRR bound tubulin tightly and stoichiometrically. Moreover, we demonstrate that interactions between the PRR and MTBR are reduced by the NTD through a conserved conformational ensemble. On the basis of these results, we propose that Tau's PRR can serve as a core tubulin-binding domain, whereas the MTBR enhances polymerization capacity by increasing the local tubulin concentration. Moreover, the NTD appears to negatively regulate tubulin-binding interactions of both of these domains. The findings of our study draw attention to a central role of the PRR in Tau function and provide mechanistic insight into Tau-mediated polymerization of tubulin.
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Affiliation(s)
- Kristen M McKibben
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Elizabeth Rhoades
- Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104 .,Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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49
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Polyphosphate Initiates Tau Aggregation through Intra- and Intermolecular Scaffolding. Biophys J 2019; 117:717-728. [PMID: 31400913 DOI: 10.1016/j.bpj.2019.07.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/28/2019] [Accepted: 07/08/2019] [Indexed: 12/20/2022] Open
Abstract
The aggregation and deposition of tau is a hallmark of a class of neurodegenerative diseases called tauopathies. Despite intensive study, cellular and molecular factors that trigger tau aggregation are not well understood. Here, we provide evidence for two mechanisms relevant to the initiation of tau aggregation in the presence of cytoplasmic polyphosphates (polyP): changes in the conformational ensemble of monomer tau and noncovalent cross-linking of multiple tau monomers. We identified conformational changes throughout full-length tau, most notably diminishment of long-range interactions between the termini coupled with compaction of the microtubule binding and proline- rich regions. We found that while the proline-rich and microtubule binding regions both contain polyP binding sites, the proline-rich region is a requisite for compaction of the microtubule binding region upon binding. Additionally, both the magnitude of the conformational change and the aggregation of tau are dependent on the chain length of the polyP polymer. Longer polyP chains are more effective at intermolecular, noncovalent cross-linking of tau. These observations provide an understanding of the initial steps of tau aggregation through interaction with a physiologically relevant aggregation inducer.
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50
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Yeboah F, Kim TE, Bill A, Dettmer U. Dynamic behaviors of α-synuclein and tau in the cellular context: New mechanistic insights and therapeutic opportunities in neurodegeneration. Neurobiol Dis 2019; 132:104543. [PMID: 31351173 DOI: 10.1016/j.nbd.2019.104543] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 10/26/2022] Open
Abstract
α-Synuclein (αS) and tau have a lot in common. Dyshomeostasis and aggregation of both proteins are central in the pathogenesis of neurodegenerative diseases: Parkinson's disease, dementia with Lewy bodies, multi-system atrophy and other 'synucleinopathies' in the case of αS; Alzheimer's disease, frontotemporal dementia, progressive supranuclear palsy and other 'tauopathies' in the case of tau. The aggregated states of αS and tau are found to be (hyper)phosphorylated, but the relevance of the phosphorylation in health or disease is not well understood. Both tau and αS are typically characterized as 'intrinsically disordered' proteins, while both engage in transient interactions with cellular components, thereby undergoing structural changes and context-specific folding. αS transiently binds to (synaptic) vesicles forming a membrane-induced amphipathic helix; tau transiently interacts with microtubules forming an 'extended structure'. The regulation and exact nature of the interactions are not fully understood. Here we review recent and previous insights into the dynamic, transient nature of αS and tau with regard to the mode of interaction with their targets, the dwell-time while bound, and the cis and trans factors underlying the frequent switching between bound and unbound states. These aspects are intimately linked to hypotheses on how subtle changes in the transient behaviors may trigger the earliest steps in the pathogenesis of the respective brain diseases. Based on a deeper understanding of transient αS and tau conformations in the cellular context, new therapeutic strategies may emerge, and it may become clearer why existing approaches have failed or how they could be optimized.
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Affiliation(s)
- Fred Yeboah
- Novartis Institute for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, MA 02139, USA
| | - Tae-Eun Kim
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Anke Bill
- Novartis Institute for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, MA 02139, USA.
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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