1
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Ashrafi-Kooshk MR, Norouzi F, Zare Karizak A, Ahmadian S, Moosavi-Movahedi AA, Riazi G. Crosstalk between tau protein autoproteolysis and amyloid fibril formation. Int J Biol Macromol 2024; 262:129953. [PMID: 38325678 DOI: 10.1016/j.ijbiomac.2024.129953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/25/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024]
Abstract
Tau cleavage has been shown to have a significant effect on protein aggregation. Tau truncation results in the formation of aggregation-prone fragments leading to toxic aggregates and also causes the formation of harmful fragments that do not aggregate. Thus, targeting proteolysis of tau would be beneficial for the development of therapeutics for Alzheimer's disease and related tauopathies. In this study, amino-terminal quantification and ThT fluorimetry were respectively used to analyze the kinetics of tau fragmentation and fibril formation. SDS-PAGE analysis of tau protein incubated with a disulfide-reducing agent demonstrated that the cysteines of tau have a crucial role in the fibrillation and autoproteolysis. However, the structures converted to amyloid fibrils were different with conformations that led to autoproteolysis. The quantification of the amino terminal indicated that the double-disulfide parallel structures formed in the presence of heparin did not have protease activity. The survey of possible tau disulfide-mediated dimer configurations suggested that the non-register single disulfide bound conformations were involved in the tau autoproteolysis process. Moreover, the inhibition of autoproteolysis resulted in the increment of aggregation rate; hence it seems that the tau auto-cleavage is the cellular defense mechanism against protein fibrillation.
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Affiliation(s)
| | - Fatemeh Norouzi
- Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, Tehran, Iran
| | - Ashkan Zare Karizak
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Gholamhossein Riazi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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2
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Chakraborty P, Rivière G, Hebestreit A, de Opakua AI, Vorberg IM, Andreas LB, Zweckstetter M. Acetylation discriminates disease-specific tau deposition. Nat Commun 2023; 14:5919. [PMID: 37739953 PMCID: PMC10517010 DOI: 10.1038/s41467-023-41672-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023] Open
Abstract
Pathogenic aggregation of the protein tau is a hallmark of Alzheimer's disease and several other tauopathies. Tauopathies are characterized by the deposition of specific tau isoforms as disease-related tau filament structures. The molecular processes that determine isoform-specific deposition of tau are however enigmatic. Here we show that acetylation of tau discriminates its isoform-specific aggregation. We reveal that acetylation strongly attenuates aggregation of four-repeat tau protein, but promotes amyloid formation of three-repeat tau. We further identify acetylation of lysine 298 as a hot spot for isoform-specific tau aggregation. Solid-state NMR spectroscopy demonstrates that amyloid fibrils formed by unmodified and acetylated three-repeat tau differ in structure indicating that site-specific acetylation modulates tau structure. The results implicate acetylation as a critical regulator that guides the selective aggregation of three-repeat tau and the development of tau isoform-specific neurodegenerative diseases.
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Affiliation(s)
- Pijush Chakraborty
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Gwladys Rivière
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Alina Hebestreit
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Alain Ibáñez de Opakua
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany
| | - Ina M Vorberg
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Rheinische Friedrich-Wilhelms-Universität, Bonn, Germany
| | - Loren B Andreas
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077, Göttingen, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077, Göttingen, Germany.
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3
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Roy R, Mandal PK, Maroon JC. Oxidative Stress Occurs Prior to Amyloid Aβ Plaque Formation and Tau Phosphorylation in Alzheimer's Disease: Role of Glutathione and Metal Ions. ACS Chem Neurosci 2023; 14:2944-2954. [PMID: 37561556 PMCID: PMC10485904 DOI: 10.1021/acschemneuro.3c00486] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023] Open
Abstract
Alzheimer's disease (AD) is an insidious and progressive neurodegenerative disorder that affects millions of people worldwide. Although the pathogenesis remains obscure, there are two dominant causal hypotheses. Since last three decades, amyloid beta (Aβ) deposition was the most prominent hypothesis, and the other is the tau hyperphosphorylation hypothesis. The confirmed diagnostic criterion for AD is the presence of neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau and the deposition of toxic oligomeric Aβ in the autopsied brain. Consistent with these hypotheses, oxidative stress (OS) is garnering major attention in AD research. OS results from an imbalance of pro-oxidants and antioxidants. There is a considerable debate in the scientific community on which process occurs first, OS or plaque deposition/tau hyperphosphorylation. Based on recent scientific observations of various laboratories including ours along with critical analysis of those information, we believe that OS is the early event that leads to oligomeric Aβ deposition as well as dimerization of tau protein and its subsequent hyperphosphorylation. This OS hypothesis immediately suggests the consideration of novel therapeutic approaches to include antioxidants involving glutathione enrichment in the brain by supplementation with or without an iron chelator.
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Affiliation(s)
- Rimil
Guha Roy
- Neuroimaging
and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122052, India
| | - Pravat K Mandal
- Neuroimaging
and Neurospectroscopy (NINS) Laboratory, National Brain Research Centre, Gurgaon 122052, India
- Florey
Institute of Neuroscience and Mental Health, Melbourne School of Medicine Campus, Melbourne, 3052 VIC, Australia
| | - Joseph C. Maroon
- Department
of Neurosurgery, University of Pittsburgh
Medical School, Pittsburgh, Pennsylvania 15213, United States
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4
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Gray ALH, Norman V, Oluwatoba DS, Prosser RA, Do TD. Potential Protective Function of Aβ 42 Monomer on Tauopathies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:472-483. [PMID: 36693165 DOI: 10.1021/jasms.2c00343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
While soluble forms of amyloid-β (Aβ) and Tau work together to drive healthy neurons into a disease state, how their interaction may control the prion-like propagation and neurotoxicity of Tau is not fully understood. The cross-linking via disulfide bond formation is crucial for Tau oligomers to obtain stable conformers and spread between cells. This work thus focuses on how Aβ42 regulates this critical process. By studying the interactions between Aβ42 and TauPHF43, a construct that mimics the Tau R3 isoform, has a similar length to Aβ42, and contains one cysteine (Cys-322), we discovered that fresh Aβ42 could protect Tau against the formation of disulfide cross-linked dimers. We showed that the monomeric and small Aβ oligomers (the "nonamyloidogenic Aβ") efficiently disassembled tau dimers and heparin-induced Tau oligomers to recover Tau monomers. Interestingly, Aβ serves the role of an antioxidant to prevent disulfide bond formation, as supported by the experiments of Aβ with cystine. Furthermore, using cyclosporine A (CycA), a macrocyclic β-sheet disruptor, we demonstrated that targeting amyloidogenic Aβ with CycA does not affect the TauPHF43 disassembly driven by Aβ42. Separately, we assessed the initial toxicity of Aβ42 and TauPHF43 in acute brain slices and found that Aβ42 is more toxic than TauPHF43 or the two peptides combined. Our work highlights a potential protective role of Aβ42 monomers in AD that was previously overlooked while focusing on the mechanism behind Aβ42 aggregation leading to tau dysfunction.
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Affiliation(s)
- Amber L H Gray
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Victoria Norman
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Damilola S Oluwatoba
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Rebecca A Prosser
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Thanh D Do
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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5
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Di Rocco G, Bernini F, Battistuzzi G, Ranieri A, Bortolotti CA, Borsari M, Sola M. Hydrogen peroxide induces heme degradation and protein aggregation in human neuroglobin: roles of the disulfide bridge and hydrogen-bonding in the distal heme cavity. FEBS J 2023; 290:148-161. [PMID: 35866372 PMCID: PMC10087938 DOI: 10.1111/febs.16581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/05/2022] [Accepted: 07/20/2022] [Indexed: 01/14/2023]
Abstract
In the present study, human neuroglobin (hNgb) was found to undergo H2 O2 -induced breakdown of the heme center at a much slower rate than other globins, namely in the timescale of hours against minutes. We investigated how the rate of the process is affected by the Cys46/Cys55 disulfide bond and the network of non-covalent interactions in the distal heme side involving Tyr44, Lys67, the His64 heme iron axial ligand and the heme propionate-7. The rate is increased by the Tyr44 to Ala and Phe mutations; however the rate is lowered by Lys67 to Ala swapping. The absence of the disulfide bridge slows down the reaction further. Therefore, the disulfide bond-controlled accessibility of the heme site and the residues at position 44 and 67 affect the activation barrier of the reaction. Wild-type and mutated species form β-amyloid aggregates in the presence of H2 O2 producing globular structures. Furthermore, the C46A/C55A, Y44A, Y44F and Y44F/C46A/C55A variants yield potentially harmful fibrils. Finally, the nucleation and growth kinetics for the aggregation of the amyloid structures can be successfully described by the Finke-Watzky model.
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Affiliation(s)
- Giulia Di Rocco
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Fabrizio Bernini
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Italy
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Italy
| | - Antonio Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | | | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Italy
| | - Marco Sola
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Italy
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6
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Holubiec MI, Gellert M, Hanschmann EM. Redox signaling and metabolism in Alzheimer's disease. Front Aging Neurosci 2022; 14:1003721. [PMID: 36408110 PMCID: PMC9670316 DOI: 10.3389/fnagi.2022.1003721] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/14/2022] [Indexed: 08/11/2023] Open
Abstract
Reduction and oxidation reactions are essential for biochemical processes. They are part of metabolic pathways and signal transduction. Reactive oxygen species (ROS) as second messengers and oxidative modifications of cysteinyl (Cys) residues are key to transduce and translate intracellular and intercellular signals. Dysregulation of cellular redox signaling is known as oxidative distress, which has been linked to various pathologies, including neurodegeneration. Alzheimer's disease (AD) is a neurodegenerative pathology linked to both, abnormal amyloid precursor protein (APP) processing, generating Aβ peptide, and Tau hyperphosphorylation and aggregation. Signs of oxidative distress in AD include: increase of ROS (H2O2, O2 •-), decrease of the levels or activities of antioxidant enzymes, abnormal oxidation of macromolecules related to elevated Aβ production, and changes in mitochondrial homeostasis linked to Tau phosphorylation. Interestingly, Cys residues present in APP form disulfide bonds that are important for intermolecular interactions and might be involved in the aggregation of Aβ. Moreover, two Cys residues in some Tau isoforms have been shown to be essential for Tau stabilization and its interaction with microtubules. Future research will show the complexities of Tau, its interactome, and the role that Cys residues play in the progression of AD. The specific modification of cysteinyl residues in redox signaling is also tightly connected to the regulation of various metabolic pathways. Many of these pathways have been found to be altered in AD, even at very early stages. In order to analyze the complex changes and underlying mechanisms, several AD models have been developed, including animal models, 2D and 3D cell culture, and ex-vivo studies of patient samples. The use of these models along with innovative, new redox analysis techniques are key to further understand the importance of the redox component in Alzheimer's disease and the identification of new therapeutic targets in the future.
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Affiliation(s)
- M. I. Holubiec
- IBioBA-MPSP Instituto de Investigación en Biomedicina de Buenos Aires, Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - M. Gellert
- Institute for Medical Biochemistry and Molecular Biology, University Medicine Greifwald, University Greifswald, Greifswald, Germany
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7
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Yin HH, Han YL, Yan X, Guan YX. Proanthocyanidins prevent tau protein aggregation and disintegrate tau filaments. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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8
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Bacchella C, Gentili S, Mozzi SI, Monzani E, Casella L, Tegoni M, Dell’Acqua S. Role of the Cysteine in R3 Tau Peptide in Copper Binding and Reactivity. Int J Mol Sci 2022; 23:ijms231810726. [PMID: 36142637 PMCID: PMC9503722 DOI: 10.3390/ijms231810726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/07/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
Tau is a widespread neuroprotein that regulates the cytoskeleton assembly. In some neurological disorders, known as tauopathies, tau is dissociated from the microtubule and forms insoluble neurofibrillary tangles. Tau comprises four pseudorepeats (R1-R4), containing one (R1, R2, R4) or two (R3) histidines, that potentially act as metal binding sites. Moreover, Cys291 and Cys322 in R2 and R3, respectively, might have an important role in protein aggregation, through possible disulfide bond formation, and/or affecting the binding and reactivity of redox-active metal ions, as copper. We, therefore, compare the interaction of copper with octadeca-R3-peptide (R3C) and with the mutant containing an alanine residue (R3A) to assess the role of thiol group. Spectrophotometric titrations allow to calculate the formation constant of the copper(I) complexes, showing a remarkable stronger interaction in the case of R3C (l log Kf = 13.4 and 10.5 for copper(I)-R3C and copper(I)-R3A, respectively). We also evaluate the oxidative reactivity associated to these copper complexes in the presence of dopamine and ascorbate. Both R3A and R3C peptides increase the capability of copper to oxidize catechols, but copper-R3C displays a peculiar mechanism due to the presence of cysteine. HPLC-MS analysis shows that cysteine can form disulfide bonds and dopamine-Cys covalent adducts, with potential implication in tau aggregation process.
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Affiliation(s)
- Chiara Bacchella
- Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Silvia Gentili
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Sara Ida Mozzi
- Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Enrico Monzani
- Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy
| | - Luigi Casella
- Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy
- Correspondence:
| | - Matteo Tegoni
- Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 11/A, 43124 Parma, Italy
| | - Simone Dell’Acqua
- Dipartimento di Chimica, Università di Pavia, Via Taramelli 12, 27100 Pavia, Italy
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9
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Prifti E, Tsakiri EN, Vourkou E, Stamatakis G, Samiotaki M, Skoulakis EMC, Papanikolopoulou K. Mical modulates Tau toxicity via cysteine oxidation in vivo. Acta Neuropathol Commun 2022; 10:44. [PMID: 35379354 PMCID: PMC8981811 DOI: 10.1186/s40478-022-01348-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/18/2022] [Indexed: 12/24/2022] Open
Abstract
Tau accumulation is clearly linked to pathogenesis in Alzheimer’s disease and other Tauopathies. However, processes leading to Tau fibrillization and reasons for its pathogenicity remain largely elusive. Mical emerged as a novel interacting protein of human Tau expressed in Drosophila brains. Mical is characterized by the presence of a flavoprotein monooxygenase domain that generates redox potential with which it can oxidize target proteins. In the well-established Drosophila Tauopathy model, we use genetic interactions to show that Mical alters Tau interactions with microtubules and the Actin cytoskeleton and greatly affects Tau aggregation propensity and Tau-associated toxicity and dysfunction. Exploration of the mechanism was pursued using a Mical inhibitor, a mutation in Mical that selectively disrupts its monooxygenase domain, Tau transgenes mutated at cysteine residues targeted by Mical and mass spectrometry analysis to quantify cysteine oxidation. The collective evidence strongly indicates that Mical’s redox activity mediates the effects on Tau via oxidation of Cys322. Importantly, we also validate results from the fly model in human Tauopathy samples by showing that MICAL1 is up-regulated in patient brains and co-localizes with Tau in Pick bodies. Our work provides mechanistic insights into the role of the Tau cysteine residues as redox-switches regulating the process of Tau self-assembly into inclusions in vivo, its function as a cytoskeletal protein and its effect on neuronal toxicity and dysfunction.
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10
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Petri L, Ábrányi-Balogh P, Vagrys D, Imre T, Varró N, Mándity I, Rácz A, Wittner L, Tóth K, Tóth EZ, Juhász T, Davis B, Keserű GM. A covalent strategy to target intrinsically disordered proteins:Discovery of novel tau aggregation inhibitors. Eur J Med Chem 2022; 231:114163. [DOI: 10.1016/j.ejmech.2022.114163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/17/2022] [Accepted: 01/26/2022] [Indexed: 12/28/2022]
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11
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Annadurai N, Malina L, Salmona M, Diomede L, Bastone A, Cagnotto A, Romeo M, Šrejber M, Berka K, Otyepka M, Hajdúch M, Das V. Antitumour drugs targeting tau R3 VQIVYK and Cys322 prevent seeding of endogenous tau aggregates by exogenous seeds. FEBS J 2021; 289:1929-1949. [PMID: 34743390 DOI: 10.1111/febs.16270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/01/2021] [Accepted: 11/05/2021] [Indexed: 12/20/2022]
Abstract
Emerging experimental evidence suggests tau pathology spreads between neuroanatomically connected brain regions in a prion-like manner in Alzheimer's disease (AD). Tau seeding, the ability of prion-like tau to recruit and misfold naïve tau to generate new seeds, is detected early in human AD brains before the development of major tau pathology. Many antitumour drugs have been reported to confer protection against neurodegeneration, supporting the repurposing of approved and experimental or investigational oncology drugs for AD therapy. In this study, we evaluated whether antitumour drugs that abrogate the generation of seed-competent aggregates of tau Repeat 3 (R3) domain peptides can prevent tau seeding and toxicity in Tau-RD P301S FRET Biosensor cells and Caenorhabditis elegans. We demonstrate that drugs that interact with the N-terminal VQIVYK or the C-terminal region housing the Cys322 prevent R3 dimerisation, abolishing the generation of prion-like R3 seeds. Preformed R3 seeds (fibrils) capped with, or R3 seeds formed in the presence of VQIVYK- or Cys322-targeting drugs have a reduced potency to cause aggregation of naïve tau in biosensor cells and protect worms from aggregate toxicity. These findings indicate that VQIVYK- or Cys322-targeting drugs may act as prophylactic agents against tau seeding.
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Affiliation(s)
- Narendran Annadurai
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic
| | - Lukáš Malina
- Department of Medical Biophysics, Faculty of Medicine and Dentistry, Palacký University in Olomouc, Olomouc, Czech Republic
| | - Mario Salmona
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Antonio Bastone
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Alfredo Cagnotto
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Margherita Romeo
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Martin Šrejber
- Czech Advanced Technology and Research Institute (CATRIN), Regional Centre of Advanced Technologies and Materials (RCPTM), Palacký University Olomouc, Olomouc, Czech Republic
| | - Karel Berka
- Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic
| | - Michal Otyepka
- Czech Advanced Technology and Research Institute (CATRIN), Regional Centre of Advanced Technologies and Materials (RCPTM), Palacký University Olomouc, Olomouc, Czech Republic.,IT4Innovations, VSB - Technical University of Ostrava, Ostrava, Czech Republic
| | - Marián Hajdúch
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic
| | - Viswanath Das
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Olomouc, Czech Republic
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12
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Hatters DM. Flipping the switch: How cysteine oxidation directs tau amyloid conformations. J Biol Chem 2021; 297:101309. [PMID: 34656563 PMCID: PMC8545682 DOI: 10.1016/j.jbc.2021.101309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2021] [Indexed: 11/15/2022] Open
Abstract
Tau can adopt distinct fibril conformations in different human neurodegenerative diseases, which may invoke distinct pathological mechanisms. In a recent issue, Weismiller et al. showed that intramolecular disulfide links between cys291 and cys322 for a specific tau isoform containing four microtubule-binding repeats direct the formation of a structurally distinct amyloid polymorph. These findings have implications in how oxidative stress can flip switches of tau polymorphism in these diseases.
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Affiliation(s)
- Danny M Hatters
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia.
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13
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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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14
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Wen J, Hong L, Krainer G, Yao QQ, Knowles TPJ, Wu S, Perrett S. Conformational Expansion of Tau in Condensates Promotes Irreversible Aggregation. J Am Chem Soc 2021; 143:13056-13064. [PMID: 34374536 DOI: 10.1021/jacs.1c03078] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Liquid-liquid phase separation (LLPS) of proteins into biomolecular condensates has emerged as a fundamental principle underpinning cellular function and malfunction. Indeed, many human pathologies, including protein misfolding diseases, are linked to aberrant liquid-to-solid phase transitions, and disease-associated protein aggregates often nucleate through phase separation. The molecular level determinants that promote pathological phase transitions remain, however, poorly understood. Here we study LLPS of the microtubule-associated protein Tau, whose aberrant aggregation is associated with a number of neurodegenerative diseases, including Alzheimer's disease. Using single molecule spectroscopy, we probe directly the conformational changes that the protein undergoes as a result of LLPS. We perform single-molecule FRET and fluorescence correlation spectroscopy experiments to monitor the intra- and intermolecular changes and demonstrate that the N- and C-terminal regions of Tau become extended, thus exposing the microtubule-binding region. These changes facilitate intermolecular interactions and allow for the formation of nanoscale clusters of Tau. Our results suggest that these clusters can promote the fibrillization of Tau, which can be dramatically accelerated by disease-related mutations P301L and P301S. Our findings thus provide important molecular insights into the mechanism of protein phase separation and the conversion of protein condensates from functional liquid assemblies to pathological aggregates.
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Affiliation(s)
- Jitao Wen
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.,University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Liu Hong
- School of Mathematics, Sun Yat-Sen University, Guangzhou 510275, China
| | - Georg Krainer
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Qiong-Qiong Yao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.,University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.,Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.,University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.,University of the Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
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15
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González C, Cartagena C, Caballero L, Melo F, Areche C, Cornejo A. The Fumarprotocetraric Acid Inhibits Tau Covalently, Avoiding Cytotoxicity of Aggregates in Cells. Molecules 2021; 26:molecules26123760. [PMID: 34205516 PMCID: PMC8234475 DOI: 10.3390/molecules26123760] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/08/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022] Open
Abstract
Neurodegenerative disorders, including Tauopathies that involve tau protein, base their pathological mechanism on forming proteinaceous aggregates, which has a deleterious effect on cells triggering an inflammatory response. Moreover, tau inhibitors can exert their mechanism of action through noncovalent and covalent interactions. Thus, Michael's addition appears as a feasible type of interaction involving an α, β unsaturated carbonyl moiety to avoid pathological confirmation and further cytotoxicity. Moreover, we isolated three compounds from Antarctic lichens Cladonia cariosa and Himantormia lugubris: protolichesterinic acid (1), fumarprotocetraric acid (2), and lichesterinic acid (3). The maleimide cysteine labeling assay showed that compounds 1, 2, and 3 inhibit at 50 µM, but compounds 2 and 3 are statistically significant. Based on its inhibition capacity, we decided to test compound 2 further. Thus, our results suggest that compound 2 remodel soluble oligomers and diminish β sheet content, as demonstrated through ThT experiments. Hence, we added externally treated oligomers with compound 2 to demonstrate that they are harmless in cell culture. First, the morphology of cells in the presence of aggregates does not suffer evident changes compared to the control. Additionally, the externally added aggregates do not provoke a substantial LDH release compared to the control, indicating that treated oligomers do not provoke membrane damage in cell culture compared with aggregates alone. Thus, in the present work, we demonstrated that Michael's acceptors found in lichens could serve as a scaffold to explore different mechanisms of action to turn tau aggregates into harmless species.
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Affiliation(s)
- Camila González
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad Andres Bello, Santiago 8370071, Chile; (C.G.); (C.C.)
| | - Constanza Cartagena
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad Andres Bello, Santiago 8370071, Chile; (C.G.); (C.C.)
| | - Leonardo Caballero
- Departamento de Física, Center for Soft Matter Research, SMAT-C, Usach, Avenida Ecuador, Estación Central, Santiago 9170124, Chile; (L.C.); (F.M.)
| | - Francisco Melo
- Departamento de Física, Center for Soft Matter Research, SMAT-C, Usach, Avenida Ecuador, Estación Central, Santiago 9170124, Chile; (L.C.); (F.M.)
| | - Carlos Areche
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago 7800003, Chile;
| | - Alberto Cornejo
- Escuela de Tecnología Médica, Facultad de Medicina, Universidad Andres Bello, Santiago 8370071, Chile; (C.G.); (C.C.)
- Correspondence:
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16
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Identification of cis-acting determinants mediating the unconventional secretion of tau. Sci Rep 2021; 11:12946. [PMID: 34155306 PMCID: PMC8217235 DOI: 10.1038/s41598-021-92433-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/31/2021] [Indexed: 12/23/2022] Open
Abstract
The deposition of tau aggregates throughout the brain is a pathological characteristic within a group of neurodegenerative diseases collectively termed tauopathies, which includes Alzheimer’s disease. While recent findings suggest the involvement of unconventional secretory pathways driving tau into the extracellular space and mediating the propagation of the disease-associated pathology, many of the mechanistic details governing this process remain elusive. In the current study, we provide an in-depth characterization of the unconventional secretory pathway of tau and identify novel molecular determinants that are required for this process. Here, using Drosophila models of tauopathy, we correlate the hyperphosphorylation and aggregation state of tau with the disease-related neurotoxicity. These newly established systems recapitulate all the previously identified hallmarks of tau secretion, including the contribution of tau hyperphosphorylation as well as the requirement for PI(4,5)P2 triggering the direct translocation of tau. Using a series of cellular assays, we demonstrate that both the sulfated proteoglycans on the cell surface and the correct orientation of the protein at the inner plasma membrane leaflet are critical determinants of this process. Finally, we identify two cysteine residues within the microtubule binding repeat domain as novel cis-elements that are important for both unconventional secretion and trans-cellular propagation of tau.
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17
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Saito T, Chiku T, Oka M, Wada-Kakuda S, Nobuhara M, Oba T, Shinno K, Abe S, Asada A, Sumioka A, Takashima A, Miyasaka T, Ando K. Disulfide bond formation in microtubule-associated tau protein promotes tau accumulation and toxicity in vivo. Hum Mol Genet 2021; 30:1955-1967. [PMID: 34137825 PMCID: PMC8522637 DOI: 10.1093/hmg/ddab162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 11/12/2022] Open
Abstract
Accumulation of microtubule-associated tau protein is thought to cause neuron loss in a group of neurodegenerative diseases called tauopathies. In diseased brains, tau molecules adopt pathological structures that propagate into insoluble forms with disease-specific patterns. Several types of posttranslational modifications in tau are known to modulate its aggregation propensity in vitro, but their influence on tau accumulation and toxicity at the whole-organism level has not been fully elucidated. Herein, we utilized a series of transgenic Drosophila models to compare systematically the toxicity induced by five tau constructs with mutations or deletions associated with aggregation, including substitutions at seven disease-associated phosphorylation sites (S7A and S7E), deletions of PHF6 and PHF6* sequences (ΔPHF6 and ΔPHF6*), and substitutions of cysteine residues in the microtubule binding repeats (C291/322A). We found that substitutions and deletions resulted in different patterns of neurodegeneration and accumulation, with C291/322A having a dramatic effect on both tau accumulation and neurodegeneration. These cysteines formed disulfide bonds in mouse primary cultured neurons and in the fly retina, and stabilized tau proteins. Additionally, they contributed to tau accumulation under oxidative stress. We also found that each of these cysteine residues contributes to the microtubule polymerization rate and microtubule levels at equilibrium, but none of them affected tau binding to polymerized microtubules. Since tau proteins expressed in the Drosophila retina are mostly present in the early stages of tau filaments self-assembly, our results suggest that disulfide bond formation by these cysteine residues could be attractive therapeutic targets.
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Affiliation(s)
- Taro Saito
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan.,Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Tomoki Chiku
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Mikiko Oka
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Satoko Wada-Kakuda
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Mika Nobuhara
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Toshiya Oba
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Kanako Shinno
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Saori Abe
- Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Akiko Asada
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan.,Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
| | - Akio Sumioka
- Faculty of Science, Department of Life Science, Gakushuin University, Tokyo, Japan
| | - Akihiko Takashima
- Faculty of Science, Department of Life Science, Gakushuin University, Tokyo, Japan
| | - Tomohiro Miyasaka
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Kanae Ando
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, Japan.,Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, Tokyo, Japan
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18
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Alquezar C, Arya S, Kao AW. Tau Post-translational Modifications: Dynamic Transformers of Tau Function, Degradation, and Aggregation. Front Neurol 2021; 11:595532. [PMID: 33488497 PMCID: PMC7817643 DOI: 10.3389/fneur.2020.595532] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 12/07/2020] [Indexed: 12/11/2022] Open
Abstract
Post-translational modifications (PTMs) on tau have long been recognized as affecting protein function and contributing to neurodegeneration. The explosion of information on potential and observed PTMs on tau provides an opportunity to better understand these modifications in the context of tau homeostasis, which becomes perturbed with aging and disease. Prevailing views regard tau as a protein that undergoes abnormal phosphorylation prior to its accumulation into the toxic aggregates implicated in Alzheimer's disease (AD) and other tauopathies. However, the phosphorylation of tau may, in fact, represent part of the normal but interrupted function and catabolism of the protein. In addition to phosphorylation, tau undergoes another forms of post-translational modification including (but not limited to), acetylation, ubiquitination, glycation, glycosylation, SUMOylation, methylation, oxidation, and nitration. A holistic appreciation of how these PTMs regulate tau during health and are potentially hijacked in disease remains elusive. Recent studies have reinforced the idea that PTMs play a critical role in tau localization, protein-protein interactions, maintenance of levels, and modifying aggregate structure. These studies also provide tantalizing clues into the possibility that neurons actively choose how tau is post-translationally modified, in potentially competitive and combinatorial ways, to achieve broad, cellular programs commensurate with the distinctive environmental conditions found during development, aging, stress, and disease. Here, we review tau PTMs and describe what is currently known about their functional impacts. In addition, we classify these PTMs from the perspectives of protein localization, electrostatics, and stability, which all contribute to normal tau function and homeostasis. Finally, we assess the potential impact of tau PTMs on tau solubility and aggregation. Tau occupies an undoubtedly important position in the biology of neurodegenerative diseases. This review aims to provide an integrated perspective of how post-translational modifications actively, purposefully, and dynamically remodel tau function, clearance, and aggregation. In doing so, we hope to enable a more comprehensive understanding of tau PTMs that will positively impact future studies.
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Affiliation(s)
| | | | - Aimee W. Kao
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, United States
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19
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Campora M, Francesconi V, Schenone S, Tasso B, Tonelli M. Journey on Naphthoquinone and Anthraquinone Derivatives: New Insights in Alzheimer's Disease. Pharmaceuticals (Basel) 2021; 14:33. [PMID: 33466332 PMCID: PMC7824805 DOI: 10.3390/ph14010033] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/27/2020] [Accepted: 12/30/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease that is characterized by memory loss, cognitive impairment, and functional decline leading to dementia and death. AD imposes neuronal death by the intricate interplay of different neurochemical factors, which continue to inspire the medicinal chemist as molecular targets for the development of new agents for the treatment of AD with diverse mechanisms of action, but also depict a more complex AD scenario. Within the wide variety of reported molecules, this review summarizes and offers a global overview of recent advancements on naphthoquinone (NQ) and anthraquinone (AQ) derivatives whose more relevant chemical features and structure-activity relationship studies will be discussed with a view to providing the perspective for the design of viable drugs for the treatment of AD. In particular, cholinesterases (ChEs), β-amyloid (Aβ) and tau proteins have been identified as key targets of these classes of compounds, where the NQ or AQ scaffold may contribute to the biological effect against AD as main unit or significant substructure. The multitarget directed ligand (MTDL) strategy will be described, as a chance for these molecules to exhibit significant potential on the road to therapeutics for AD.
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Affiliation(s)
| | | | | | | | - Michele Tonelli
- Dipartimento di Farmacia, Università degli Studi di Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; (M.C.); (V.F.); (S.S.); (B.T.)
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20
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The Two Cysteines of Tau Protein Are Functionally Distinct and Contribute Differentially to Its Pathogenicity in Vivo. J Neurosci 2020; 41:797-810. [PMID: 33334867 DOI: 10.1523/jneurosci.1920-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/21/2020] [Accepted: 11/25/2020] [Indexed: 11/21/2022] Open
Abstract
Although Tau accumulation is clearly linked to pathogenesis in Alzheimer's disease and other Tauopathies, the mechanism that initiates the aggregation of this highly soluble protein in vivo remains largely unanswered. Interestingly, in vitro Tau can be induced to form fibrillar filaments by oxidation of its two cysteine residues, generating an intermolecular disulfide bond that promotes dimerization and fibrillization. The recently solved structures of Tau filaments revealed that the two cysteine residues are not structurally equivalent since Cys-322 is incorporated into the core of the fibril, whereas Cys-291 projects away from the core to form the fuzzy coat. Here, we examined whether mutation of these cysteines to alanine affects differentially Tau mediated toxicity and dysfunction in the well-established Drosophila Tauopathy model. Experiments were conducted with both sexes, or with either sex. Each cysteine residue contributes differentially to Tau stability, phosphorylation status, aggregation propensity, resistance to stress, learning, and memory. Importantly, our work uncovers a critical role of Cys-322 in determining Tau toxicity and dysfunction.SIGNIFICANCE STATEMENT Cysteine-291 and Cysteine-322, the only two cysteine residues of Tau present in only 4-Repeat or all isoforms, respectively, have competing functions: as the key residues in the catalytic center, they enable Tau auto-acetylation; and as residues within the microtubule-binding repeat region are important not only for Tau function but also instrumental in the initiation of Tau aggregation. In this study, we present the first in vivo evidence that their substitution leads to differential consequences on Tau's physiological and pathophysiological functions. These differences raise the possibility that cysteine residues play a potential role in determining the functional diversity between isoforms.
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21
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Chidambaram H, Chinnathambi S. Role of cysteines in accelerating Tau filament formation. J Biomol Struct Dyn 2020; 40:4366-4375. [PMID: 33317395 DOI: 10.1080/07391102.2020.1856720] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease is majorly associated with intracellular accumulation of Tau into paired helical filaments and tangles. The self-aggregated dimeric and oligomeric species of Tau formed are more toxic to neuronal cells and acts as seeds for filament formation. The two cysteine residues and the two hexapeptide regions of full-length Tau play a key role in initialization and filament formation during Tau aggregation. The role of cysteine residues in Tau aggregation has been studied by in-vitro aggregation assay that was measured by Thioflavin S fluorescence to observe the kinetics of aggregation. In this study, we have performed in-vitro aggregation assay with recombinant full-length Tau and the cysteine mutants to understand the mechanism of cysteine independent Tau aggregation. Here, we report that cysteine mutant full-length Tau can aggregate to form filaments under in-vitro conditions. To visualize the polymorphisms of Tau and cysteine mutants under different aggregation conditions anionic cofactor, heparin was employed. Wild-type Tau showed rapid aggregation to form oligomers and filaments. On the other hand, the cysteine mutant delayed the initial Tau aggregation. This indicates the importance of cysteine residues in accelerating initial Tau nucleation for its aggregation. The filament morphology of wild-type and cysteine mutant Tau has been characterized using transmission electron microscopy and high-resolution transmission electron microscopy.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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22
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Soeda Y, Takashima A. New Insights Into Drug Discovery Targeting Tau Protein. Front Mol Neurosci 2020; 13:590896. [PMID: 33343298 PMCID: PMC7744460 DOI: 10.3389/fnmol.2020.590896] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022] Open
Abstract
Microtubule-associated protein tau is characterized by the fact that it is an intrinsically disordered protein due to its lack of a stable conformation and high flexibility. Intracellular inclusions of fibrillar forms of tau with a β-sheet structure accumulate in the brain of patients with Alzheimer's disease and other tauopathies. Accordingly, detachment of tau from microtubules and transition of tau from a disordered state to an abnormally aggregated state are essential events preceding the onset of tau-related diseases. Many reports have shown that this transition is caused by post-translational modifications, including hyperphosphorylation and acetylation. The misfolded tau is self-assembled and forms a tau oligomer before the appearance of tau inclusions. Animal and pathological studies using human samples have demonstrated that tau oligomer formation contributes to neuronal loss. During the progression of tauopathies, tau seeds are released from cells and incorporated into other cells, leading to the propagation of pathological tau aggregation. Accumulating evidence suggests several potential approaches for blocking tau-mediated toxicity: (1) direct inhibition of pathological tau aggregation and (2) inhibition of tau post-translational modifications that occur prior to pathological tau aggregation, (3) inhibition of tau propagation and (4) stabilization of microtubules. In addition to traditional low-molecular-weight compounds, newer drug discovery approaches such as the development of medium-molecular-weight drugs (peptide- or oligonucleotide-based drugs) and high-molecular-weight drugs (antibody-based drugs) provide alternative pathways to preventing the formation of abnormal tau. Of particular interest are recent studies suggesting that tau droplet formation by liquid-liquid phase separation may be the initial step in aberrant tau aggregation, as well results that implicate roles for tau in dendritic and nuclear functions. Here, we review the mechanisms through which drugs can target tau and consider recent clinical trials for the treatment of tauopathies. In addition, we discuss the utility of these newer strategies and propose future directions for research on tau-targeted therapeutics.
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Affiliation(s)
- Yoshiyuki Soeda
- Laboratory for Alzheimer's Disease, Department of Life Science, Faculty of Science, Gakushuin University, Tokyo, Japan
| | - Akihiko Takashima
- Laboratory for Alzheimer's Disease, Department of Life Science, Faculty of Science, Gakushuin University, Tokyo, Japan
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23
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Karikari TK, Keeling S, Hill E, Lantero Rodrı́guez J, Nagel DA, Becker B, Höglund K, Zetterberg H, Blennow K, Hill EJ, Moffat KG. Extensive Plasmid Library to Prepare Tau Protein Variants and Study Their Functional Biochemistry. ACS Chem Neurosci 2020; 11:3117-3129. [PMID: 32833429 DOI: 10.1021/acschemneuro.0c00469] [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] [Indexed: 12/13/2022] Open
Abstract
Tau neurofibrillary tangles are key pathological features of Alzheimer's disease and other tauopathies. Recombinant protein technology is vital for studying the structure and function of tau in physiology and aggregation in pathophysiology. However, open-source and well-characterized plasmids for efficiently expressing and purifying different tau variants are lacking. We generated 44 sequence-verified plasmids including those encoding full length (FL) tau-441, its four-repeat microtubule-binding (K18) fragment, and their respective selected familial pathological variants (N279K, V337M, P301L, C291R, and S356T). Moreover, plasmids for expressing single (C291A), double (C291A/C322A), and triple (C291A/C322A/I260C) cysteine-modified variants were generated to study alterations in cysteine content and locations. Furthermore, protocols for producing representative tau forms were developed. We produced and characterized the aggregation behavior of the triple cysteine-modified tau-K18, often used in real-time cell internalization and aggregation studies because it can be fluorescently labeled on a cysteine outside the microtubule-binding core. Similar to the wild type (WT), triple cysteine-modified tau-K18 aggregated by progressive β-sheet enrichment, albeit at a slower rate. On prolonged incubation, cysteine-modified K18 formed paired helical filaments similar to those in Alzheimer's disease, sharing morphological phenotypes with WT tau-K18 filaments. Nonetheless, cysteine-modified tau-K18 filaments were significantly shorter (p = 0.002) and mostly wider than WT filaments, explainable by their different principal filament elongation pathways: vertical (end-to-end) and lateral growth for WT and cysteine-modified, respectively. Cysteine rearrangement may therefore induce filament polymorphism. Together, the plasmid library, the protein production methods, and the new insights into cysteine-dependent aggregation should facilitate further studies and the design of antiaggregation agents.
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Affiliation(s)
- Thomas K. Karikari
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
- Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry CV4 7AL, U.K
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
| | - Sophie Keeling
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Emily Hill
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Juan Lantero Rodrı́guez
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
| | - David A. Nagel
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, U.K
| | - Bruno Becker
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 80, Sweden
| | - Kina Höglund
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 80, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 80, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London WC1E 6BT, U.K
- UK Dementia Research Institute at UCL, London WC1E 6BT, U.K
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg SE 43180, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 80, Sweden
| | - Eric J. Hill
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, U.K
| | - Kevin G. Moffat
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
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24
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Merezhko M, Uronen RL, Huttunen HJ. The Cell Biology of Tau Secretion. Front Mol Neurosci 2020; 13:569818. [PMID: 33071756 PMCID: PMC7539664 DOI: 10.3389/fnmol.2020.569818] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/26/2020] [Indexed: 12/27/2022] Open
Abstract
The progressive accumulation and spread of misfolded tau protein in the nervous system is the hallmark of tauopathies, progressive neurodegenerative diseases with only symptomatic treatments available. A growing body of evidence suggests that spreading of tau pathology can occur via cell-to-cell transfer involving secretion and internalization of pathological forms of tau protein followed by templated misfolding of normal tau in recipient cells. Several studies have addressed the cell biological mechanisms of tau secretion. It now appears that instead of a single mechanism, cells can secrete tau via three coexisting pathways: (1) translocation through the plasma membrane; (2) membranous organelles-based secretion; and (3) ectosomal shedding. The relative importance of these pathways in the secretion of normal and pathological tau is still elusive, though. Moreover, glial cells contribute to tau propagation, and the involvement of different cell types, as well as different secretion pathways, complicates the understanding of prion-like propagation of tauopathy. One of the important regulators of tau secretion in neuronal activity, but its mechanistic connection to tau secretion remains unclear and may involve all three secretion pathways of tau. This review article summarizes recent advancements in the field of tau secretion with an emphasis on cell biological aspects of the secretion process and discusses the role of neuronal activity and glial cells in the spread of pathological forms of tau.
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Affiliation(s)
- Maria Merezhko
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | | | - Henri J Huttunen
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
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25
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Karikari TK, Thomas R, Moffat KG. The C291R Tau Variant Forms Different Types of Protofibrils. Front Mol Neurosci 2020; 13:39. [PMID: 32256313 PMCID: PMC7093375 DOI: 10.3389/fnmol.2020.00039] [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: 12/17/2019] [Accepted: 02/27/2020] [Indexed: 11/25/2022] Open
Abstract
Mutations in the MAPT gene can lead to disease-associated variants of tau. However, the pathological mechanisms behind these genetic tauopathies are poorly understood. Here, we characterized the aggregation stages and conformational changes of tau C291R, a recently described MAPT mutation with potential pathogenic functions. The C291R variant of the tau four-repeat domain (tau-K18; a functional fragment with increased aggregation propensity compared with the full-length protein), aggregated into a mix of granular oligomers, amorphous and annular pore-like aggregates, in native-state and heparin-treated reactions as observed using atomic force microscopy (AFM) and negative-stained electron microscopy. On extended incubation in the native-state, tau-K18 C291R oligomers, unlike wild type (WT) tau-K18, aggregated to form protofibrils of four different phenotypes: (1) spherical annular; (2) spherical annular encapsulating granular oligomers; (3) ring-like annular but non-spherical; and (4) linear protofibrils. The ring-like tau-K18 C291R aggregates shared key properties of annular protofibrils previously described for other amyloidogenic proteins, in addition to two unique features: irregular/non-spherical-shaped annular protofibrils, and spherical protofibrils encapsulating granular oligomers. Tau-K18 C291R monomers had a circular dichroism (CD) peak at ~210 nm compared with ~199 nm for tau-K18 WT. These data suggest mutation-enhanced β-sheet propensity. Together, we describe the characterization of tau-K18 C291R, the first genetic mutation substituting a cysteine residue. The aggregation mechanism of tau-K18 C291R appears to involve β-sheet-rich granular oligomers which rearrange to form unique protofibrillar structures.
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Affiliation(s)
- Thomas K Karikari
- School of Life Sciences, University of Warwick, Coventry, United Kingdom.,Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, United Kingdom.,Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Rachel Thomas
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Kevin G Moffat
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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26
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Areche C, Zapata F, González M, Díaz E, Montecinos R, Hernández M, Melo F, Cornejo A. Anthraquinone Derivative Reduces Tau Oligomer Progression by Inhibiting Cysteine-Cysteine Interaction. ChemistryOpen 2019; 8:554-559. [PMID: 31065505 PMCID: PMC6496470 DOI: 10.1002/open.201800222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 01/05/2023] Open
Abstract
Tau protein is a natively unfolded protein whose primary role is to participate in axonal transport closely associated with microtubules. Neurodegenerative disorders including Alzheimer's disease and Tauopathies involved tau protein that is found hyperphosphorylated in vivo; then, tau is detached from microtubules to form toxic aggregates or oligomers, which have a deleterious effect on membranes, triggering an inflammatory response. Considering finding tau inhibitors, we isolated two compounds in the ethyl acetate extract from Xanthoria ectaneoides (Nyl.) Zahlbr; ergosterol peroxide (1) and a new anthraquinone (2). We established the structure through spectroscopic data and biogenic considerations, and we named it "2-hydroxy-3-((8-hydroxy-3-methoxy-6-methylanthraquinonyl)oxy)propanoic acid". This new anthraquinone was evaluated as a tau inhibitor by ThT fluorescence, dot blot assays and total internal reflection fluorescence microscopy. Our results strongly suggest that this anthraquinone remodels soluble oligomers and diminishes β-sheet content. Moreover, through the fluorescence labeling of cysteine inside of the microtubule-binding domain (4R), we showed that this anthraquinone could reduce the oligomers progression by inhibiting cysteine interactions.
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Affiliation(s)
- Carlos Areche
- Departamento de Química, Facultad de CienciasUniversidad de ChileLas Palmeras 34257800003Santiago-Chile
| | - Francisca Zapata
- Escuela Tecnología MédicaFacultad de MedicinaSazie 23158370092Santiago-Chile
| | - Mathias González
- Escuela Tecnología MédicaFacultad de MedicinaSazie 23158370092Santiago-Chile
| | - Esteban Díaz
- Escuela Tecnología MédicaFacultad de MedicinaSazie 23158370092Santiago-Chile
| | | | - Marcos Hernández
- Departamento de Química, Facultad de CienciasUniversidad de ChileLas Palmeras 34257800003Santiago-Chile
| | - Francisco Melo
- Departamento de FísicaAvenida Ecuador 34939170124Santiago-Chile
| | - Alberto Cornejo
- Escuela Tecnología MédicaFacultad de MedicinaSazie 23158370092Santiago-Chile
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27
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Martinelli AHS, Lopes FC, John EBO, Carlini CR, Ligabue-Braun R. Modulation of Disordered Proteins with a Focus on Neurodegenerative Diseases and Other Pathologies. Int J Mol Sci 2019; 20:ijms20061322. [PMID: 30875980 PMCID: PMC6471803 DOI: 10.3390/ijms20061322] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/03/2019] [Accepted: 02/12/2019] [Indexed: 12/15/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) do not have rigid 3D structures, showing changes in their folding depending on the environment or ligands. Intrinsically disordered proteins are widely spread in eukaryotic genomes, and these proteins participate in many cell regulatory metabolism processes. Some IDPs, when aberrantly folded, can be the cause of some diseases such as Alzheimer′s, Parkinson′s, and prionic, among others. In these diseases, there are modifications in parts of the protein or in its entirety. A common conformational variation of these IDPs is misfolding and aggregation, forming, for instance, neurotoxic amyloid plaques. In this review, we discuss some IDPs that are involved in neurodegenerative diseases (such as beta amyloid, alpha synuclein, tau, and the “IDP-like” PrP), cancer (p53, c-Myc), and diabetes (amylin), focusing on the structural changes of these IDPs that are linked to such pathologies. We also present the IDP modulation mechanisms that can be explored in new strategies for drug design. Lastly, we show some candidate drugs that can be used in the future for the treatment of diseases caused by misfolded IDPs, considering that cancer therapy has more advanced research in comparison to other diseases, while also discussing recent and future developments in this area of research. Therefore, we aim to provide support to the study of IDPs and their modulation mechanisms as promising approaches to combat such severe diseases.
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Affiliation(s)
- Anne H S Martinelli
- Department of Molecular Biology and Biotechnology & Department of Biophysics, Biosciences Institute-IB, (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Fernanda C Lopes
- Center for Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Elisa B O John
- Center for Biotechnology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
| | - Célia R Carlini
- Graduate Program in Cell and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre CEP 91501-970, RS, Brazil.
- Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 91410-000, RS, Brazil.
- Brain Institute-InsCer, Laboratory of Neurotoxins, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre CEP 90610-000, RS, Brazil.
| | - Rodrigo Ligabue-Braun
- Department of Pharmaceutical Sciences, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre CEP 90050-170, RS, Brazil.
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28
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Honda R. Role of the Disulfide Bond in Prion Protein Amyloid Formation: A Thermodynamic and Kinetic Analysis. Biophys J 2019; 114:885-892. [PMID: 29490248 DOI: 10.1016/j.bpj.2017.12.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/15/2017] [Accepted: 12/27/2017] [Indexed: 01/19/2023] Open
Abstract
Prion diseases are associated with the structural conversion of prion protein (PrP) to a β-sheet-rich aggregate, PrPSc. Previous studies have indicated that a reduction of the disulfide bond linking C179 and C214 of PrP yields an amyloidlike β-rich aggregate in vitro. To gain mechanistic insights into the reduction-induced aggregation, here I characterized how disulfide bond reduction modulates the protein folding/misfolding landscape of PrP, by examining 1) the equilibrium stabilities of the native (N) and aggregated states relative to the unfolded (U) state, 2) the transition barrier separating the U and aggregated states, and 3) the final structure of amyloidlike misfolded aggregates. Kinetic and thermodynamic experiments revealed that disulfide bond reduction decreases the equilibrium stabilities of both the N and aggregated states by ∼3 kcal/mol, without changing either the amyloidlike aggregate structure, at least at the secondary structural level, or the transition barrier of aggregation. Therefore, disulfide bond reduction modulates the protein folding/misfolding landscape by entropically stabilizing disordered states, including the U and transition state of aggregation. This also indicates that the equilibrium stability of the N state, but not the transition barrier of aggregation, is the dominant factor determining the reduction-induced aggregation of PrP.
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Affiliation(s)
- Ryo Honda
- The United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan; Department of Molecular Pathobiochemistry, Graduate School of Medicine, Gifu University, Gifu, Japan.
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29
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Karikari TK, Nagel DA, Grainger A, Clarke-Bland C, Hill EJ, Moffat KG. Preparation of stable tau oligomers for cellular and biochemical studies. Anal Biochem 2018; 566:67-74. [PMID: 30315761 PMCID: PMC6331036 DOI: 10.1016/j.ab.2018.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/26/2018] [Accepted: 10/08/2018] [Indexed: 02/02/2023]
Abstract
Increasing evidence suggests that small oligomers are the principal neurotoxic species of tau in Alzheimer's disease and other tauopathies. However, mechanisms of tau oligomer-mediated neurodegeneration are poorly understood. The transience of oligomers due to aggregation can compromise the stability of oligomers prepared in vitro. Consequently, we sought to develop an efficient method which maintains the stability and globular conformation of preformed oligomers. This study demonstrates that labeling a single-cysteine form of the pro-aggregant tau four-repeat region (K18) with either Alexa Fluor 488-C5-maleimide or N-ethylmaleimide in reducing conditions stabilizes oligomers by impeding their further aggregation. Furthermore, the use of this approach to study the propagation of labeled extracellular tau K18 oligomers into human neuroblastoma cells and human stem cell-derived neurons is described. This method is potentially applicable for preparing stabilized oligomers of tau for diagnostic and biomarker tests, as well as for in vitro structure-activity relationship assays. The transient nature of tau aggregation makes it difficult to maintain the stability of preformed oligomers. Efficient labeling of tau K18 with Alexa Fluor-488-C5-maleimide or N-ethyl maleimide stabilizes the resulting oligomers. Oligomers applied exogenously are propagated intracellularly by cultured human iPSC neurons and neuroblastoma cells. Oligomer preparation by maleimide labeling allows mechanistic studies of tau aggregation and its link to neurodegeneration.
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Affiliation(s)
- Thomas K Karikari
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK; Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, CV4 7AL, UK.
| | - David A Nagel
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Alastair Grainger
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | | | - Eric J Hill
- School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Kevin G Moffat
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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30
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Martinho M, Allegro D, Huvent I, Chabaud C, Etienne E, Kovacic H, Guigliarelli B, Peyrot V, Landrieu I, Belle V, Barbier P. Two Tau binding sites on tubulin revealed by thiol-disulfide exchanges. Sci Rep 2018; 8:13846. [PMID: 30218010 PMCID: PMC6138654 DOI: 10.1038/s41598-018-32096-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/14/2018] [Indexed: 01/25/2023] Open
Abstract
Tau is a Microtubule-associated protein that induces and stabilizes the formation of the Microtubule cytoskeleton and plays an important role in neurodegenerative diseases. The Microtubules binding region of Tau has been determined for a long time but where and how Tau binds to its partner still remain a topic of debate. We used Site Directed Spin Labeling combined with EPR spectroscopy to monitor Tau upon binding to either Taxol-stabilized MTs or to αβ-tubulin when Tau is directly used as an inducer of MTs formation. Using maleimide-functionalized labels grafted on the two natural cysteine residues of Tau, we found in both cases that Tau remains highly flexible in these regions confirming the fuzziness of Tau:MTs complexes. More interestingly, using labels linked by a disulfide bridge, we evidenced for the first time thiol disulfide exchanges between αβ-tubulin or MTs and Tau. Additionally, Tau fragments having the two natural cysteines or variants containing only one of them were used to determine the role of each cysteine individually. The difference observed in the label release kinetics between preformed MTs or Tau-induced MTs, associated to a comparison of structural data, led us to propose two putative binding sites of Tau on αβ-tubulin.
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Affiliation(s)
- Marlène Martinho
- Aix-Marseille Univ, CNRS, UMR 7281 BIP, Bioénergétique et Ingénierie des Protéines, Marseille, France
| | - Diane Allegro
- Aix-Marseille Univ, CNRS, UMR 7051, INP, Institut de Neurophysiopathologie, Marseille, France
| | | | - Charlotte Chabaud
- Aix-Marseille Univ, CNRS, UMR 7281 BIP, Bioénergétique et Ingénierie des Protéines, Marseille, France.,Aix-Marseille Univ, CNRS, UMR 7051, INP, Institut de Neurophysiopathologie, Marseille, France
| | - Emilien Etienne
- Aix-Marseille Univ, CNRS, UMR 7281 BIP, Bioénergétique et Ingénierie des Protéines, Marseille, France
| | - Hervé Kovacic
- Aix-Marseille Univ, CNRS, UMR 7051, INP, Institut de Neurophysiopathologie, Marseille, France
| | - Bruno Guigliarelli
- Aix-Marseille Univ, CNRS, UMR 7281 BIP, Bioénergétique et Ingénierie des Protéines, Marseille, France
| | - Vincent Peyrot
- Aix-Marseille Univ, CNRS, UMR 7051, INP, Institut de Neurophysiopathologie, Marseille, France
| | | | - Valérie Belle
- Aix-Marseille Univ, CNRS, UMR 7281 BIP, Bioénergétique et Ingénierie des Protéines, Marseille, France.
| | - Pascale Barbier
- Aix-Marseille Univ, CNRS, UMR 7051, INP, Institut de Neurophysiopathologie, Marseille, France.
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31
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Al-Hilaly YK, Pollack SJ, Rickard JE, Simpson M, Raulin AC, Baddeley T, Schellenberger P, Storey JMD, Harrington CR, Wischik CM, Serpell LC. Cysteine-Independent Inhibition of Alzheimer's Disease-like Paired Helical Filament Assembly by Leuco-Methylthioninium (LMT). J Mol Biol 2018; 430:4119-4131. [PMID: 30121297 DOI: 10.1016/j.jmb.2018.08.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/12/2018] [Accepted: 08/09/2018] [Indexed: 12/01/2022]
Abstract
Alzheimer's disease is a tauopathy characterized by pathological fibrillization of tau protein to form the paired helical filaments (PHFs), which constitute neurofibrillary tangles. The methylthioninium (MT) moiety reverses the proteolytic stability of the PHF core and is in clinical development for treatment of Alzheimer's disease in a stable reduced form as leuco-MT. It has been hypothesized that MT acts via oxidation of cysteine residues, which is incompatible with activity in the predominantly reducing environment of living cells. We have shown recently that the PHF-core tau unit assembles spontaneously in vitro to form PHF-like filaments. Here we describe studies using circular dichroism, SDS-PAGE, transmission electron microscopy and site-directed mutagenesis to elucidate the mechanism of action of the MT moiety. We show that MT inhibitory activity is optimal in reducing conditions, that the active moiety is the reduced leuco-MT form of the molecule and that its mechanism of action is cysteine independent.
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Affiliation(s)
- Youssra K Al-Hilaly
- Dementia Research Group, School of Life Sciences, University of Sussex, Falmer, E Sussex, BN1 9QG, United Kingdom; Chemistry Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - Saskia J Pollack
- Dementia Research Group, School of Life Sciences, University of Sussex, Falmer, E Sussex, BN1 9QG, United Kingdom
| | - Janet E Rickard
- Institute of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, AB25 2ZP, United Kingdom
| | - Michael Simpson
- TauRx Therapeutics Ltd., Aberdeen, AB25 2ZP, United Kingdom; Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom
| | - Ana-Caroline Raulin
- Dementia Research Group, School of Life Sciences, University of Sussex, Falmer, E Sussex, BN1 9QG, United Kingdom
| | - Thomas Baddeley
- TauRx Therapeutics Ltd., Aberdeen, AB25 2ZP, United Kingdom; Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom
| | - Pascale Schellenberger
- Dementia Research Group, School of Life Sciences, University of Sussex, Falmer, E Sussex, BN1 9QG, United Kingdom
| | - John M D Storey
- TauRx Therapeutics Ltd., Aberdeen, AB25 2ZP, United Kingdom; Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom
| | - Charles R Harrington
- Institute of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, AB25 2ZP, United Kingdom; Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom
| | - Claude M Wischik
- Institute of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, AB25 2ZP, United Kingdom; Department of Chemistry, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom.
| | - Louise C Serpell
- Dementia Research Group, School of Life Sciences, University of Sussex, Falmer, E Sussex, BN1 9QG, United Kingdom.
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32
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Rafiee S, Asadollahi K, Riazi G, Ahmadian S, Saboury AA. Vitamin B12 Inhibits Tau Fibrillization via Binding to Cysteine Residues of Tau. ACS Chem Neurosci 2017; 8:2676-2682. [PMID: 28841372 DOI: 10.1021/acschemneuro.7b00230] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Two mechanisms underlie the inhibitory/acceleratory action of chemical compounds on tau aggregation including the regulation of cellular kinases and phosphatases activity and direct binding to tau protein. Vitamin B12 is one of the tau polymerization inhibitors, and its deficiency is linked to inactivation of protein phosphatase 2A and subsequently hyperphosphorylation and aggregation of tau protein. Regarding the structure and function of vitamin B12 and tau protein, we assumed that vitamin B12 is also able to directly bind to tau protein. Hence, we investigated the interaction of vitamin B12 with tau protein in vitro using fluorometry and circular dichrosim. Interaction studies was followed by investigation into the effect of vitamin B12 on tau aggregation using ThT fluorescence, circular dichroism, transmission electron microscopy, and SDS-PAGE. The results indicated that vitamin B12 interacts with tau protein and prevents fibrillization of tau protein. Blocking the cysteine residues of tau confirmed the cysteine-mediated binding of vitamin B12 to tau and showed that binding to cysteine is essential for inhibitory effect of vitamin B12 on tau aggregation. SDS-PAGE analysis indicated that vitamin B12 inhibits tau aggregation and that tau oligomers formed in the presence of vitamin B12 are mostly SDS-soluble. We propose that direct binding of vitamin B12 is another mechanism underlying the inhibitory role of vitamin B12 on tau aggregation and neurodegeneration.
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Affiliation(s)
- Saharnaz Rafiee
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Kazem Asadollahi
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Gholamhossein Riazi
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Ali Akbar Saboury
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
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33
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A 31-residue peptide induces aggregation of tau's microtubule-binding region in cells. Nat Chem 2017; 9:874-881. [PMID: 28837163 DOI: 10.1038/nchem.2754] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/23/2017] [Indexed: 12/22/2022]
Abstract
The self-propagation of misfolded conformations of tau underlies neurodegenerative diseases, including Alzheimer's. There is considerable interest in discovering the minimal sequence and active conformational nucleus that defines this self-propagating event. The microtubule-binding region, spanning residues 244-372, reproduces much of the aggregation behaviour of tau in cells and animal models. Further dissection of the amyloid-forming region to a hexapeptide from the third microtubule-binding repeat resulted in a peptide that rapidly forms fibrils in vitro. We show that this peptide lacks the ability to seed aggregation of tau244-372 in cells. However, as the hexapeptide is gradually extended to 31 residues, the peptides aggregate more slowly and gain potent activity to induce aggregation of tau244-372 in cells. X-ray fibre diffraction, hydrogen-deuterium exchange and solid-state NMR studies map the beta-forming region to a 25-residue sequence. Thus, the nucleus for self-propagating aggregation of tau244-372 in cells is packaged in a remarkably small peptide.
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34
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Soeda Y, Yoshikawa M, Almeida OFX, Sumioka A, Maeda S, Osada H, Kondoh Y, Saito A, Miyasaka T, Kimura T, Suzuki M, Koyama H, Yoshiike Y, Sugimoto H, Ihara Y, Takashima A. Toxic tau oligomer formation blocked by capping of cysteine residues with 1,2-dihydroxybenzene groups. Nat Commun 2015; 6:10216. [PMID: 26671725 PMCID: PMC4703892 DOI: 10.1038/ncomms10216] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/13/2015] [Indexed: 12/26/2022] Open
Abstract
Neurofibrillary tangles, composed of hyperphosphorylated tau fibrils, are a pathological hallmark of Alzheimer's disease; the neurofibrillary tangle load correlates strongly with clinical progression of the disease. A growing body of evidence indicates that tau oligomer formation precedes the appearance of neurofibrillary tangles and contributes to neuronal loss. Here we show that tau oligomer formation can be inhibited by compounds whose chemical backbone includes 1,2-dihydroxybenzene. Specifically, we demonstrate that 1,2-dihydroxybenzene-containing compounds bind to and cap cysteine residues of tau and prevent its aggregation by hindering interactions between tau molecules. Further, we show that orally administered DL-isoproterenol, an adrenergic receptor agonist whose skeleton includes 1,2-dihydroxybenzene and which penetrates the brain, reduces the levels of detergent-insoluble tau, neuronal loss and reverses neurofibrillary tangle-associated brain dysfunction. Thus, compounds that target the cysteine residues of tau may prove useful in halting the progression of Alzheimer's disease and other tauopathies. Aggregation of microtubule associated protein tau is one of cause of neuronal loss in tauopathies including Alzheimer's disease. Here, the authors show that compounds with a 1,2-dihydroxybenzene skeleton can modify cysteine residues in tau and block toxic tau aggregation.
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Affiliation(s)
- Yoshiyuki Soeda
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Misato Yoshikawa
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Osborne F X Almeida
- Department of Stress Neurology and Neurogenesis, Max Planck Institute of Psychiatry, Kraepelinstrasse, 2-10, Munich 80804, Germany
| | - Akio Sumioka
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Sumihiro Maeda
- Gladstone Institute of Neurological Disease, University of California, San Francisco, California 94158-2261, USA
| | - Hiroyuki Osada
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science (CSRS), RIKEN, Wako, Saitama 351-0198, Japan.,Antibiotics Laboratory, Advanced Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yasumitsu Kondoh
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science (CSRS), RIKEN, Wako, Saitama 351-0198, Japan.,Antibiotics Laboratory, Advanced Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Akiko Saito
- Graduate School of Engineering, Osaka Electro-communication University (OECU), 18-8 Hatsu-cho, Osaka 572-8530, Japan
| | - Tomohiro Miyasaka
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan
| | - Tetsuya Kimura
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Masaaki Suzuki
- Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Hiroko Koyama
- Division of Regeneration and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
| | - Yuji Yoshiike
- Alzheimer's Disease Project Team, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Hachiro Sugimoto
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kizugawa, Kyoto 619-0225, Japan
| | - Yasuo Ihara
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0394, Japan.,Laboratory of Cognition and Aging, Doshisha University, Kizugawa 619-0225, Japan
| | - Akihiko Takashima
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
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35
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Huvent I, Kamah A, Cantrelle FX, Barois N, Slomianny C, Smet-Nocca C, Landrieu I, Lippens G. A functional fragment of Tau forms fibers without the need for an intermolecular cysteine bridge. Biochem Biophys Res Commun 2014; 445:299-303. [PMID: 24502945 DOI: 10.1016/j.bbrc.2014.01.161] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 01/27/2014] [Indexed: 11/16/2022]
Abstract
We study the aggregation of a fragment of the neuronal protein Tau that contains part of the proline rich domain and of the microtubule binding repeats. When incubated at 37 °C with heparin, the fragment readily forms fibers as witnessed by Thioflavin T fluorescence. Electron microscopy and NMR spectroscopy show bundled ribbon like structures with most residues rigidly incorporated in the fibril. Without its cysteines, this fragment still forms fibers of a similar morphology, but with lesser Thioflavin T binding sites and more mobility for the C-terminal residues.
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Affiliation(s)
- Isabelle Huvent
- CNRS UMR 8576, University of Lille1, 59655 Villeneuve d'Ascq, France
| | - Amina Kamah
- CNRS UMR 8576, University of Lille1, 59655 Villeneuve d'Ascq, France
| | | | - Nicolas Barois
- Plate-forme BICeL-IFR142, Institut Pasteur de Lille, Lille, France
| | - Christian Slomianny
- Inserm U1003, Laboratoire de physiologie cellulaire, Université Lille 1, 59650 Villeneuve d'Ascq, France
| | | | - Isabelle Landrieu
- CNRS UMR 8576, University of Lille1, 59655 Villeneuve d'Ascq, France
| | - Guy Lippens
- CNRS UMR 8576, University of Lille1, 59655 Villeneuve d'Ascq, France.
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36
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Walker S, Ullman O, Stultz CM. Using intramolecular disulfide bonds in tau protein to deduce structural features of aggregation-resistant conformations. J Biol Chem 2012; 287:9591-600. [PMID: 22291015 PMCID: PMC3308815 DOI: 10.1074/jbc.m111.336107] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/17/2012] [Indexed: 01/11/2023] Open
Abstract
Because tau aggregation likely plays a role in a number of neurodegenerative diseases, understanding the processes that affect tau aggregation is of considerable importance. One factor that has been shown to influence the aggregation propensity is the oxidation state of the protein itself. Tau protein, which contains two naturally occurring cysteine residues, can form both intermolecular disulfide bonds and intramolecular disulfide bonds. Several studies suggest that intermolecular disulfide bonds can promote tau aggregation in vitro. By contrast, although there are data to suggest that intramolecular disulfide bond formation retards tau aggregation in vitro, the precise mechanism underlying this observation remains unclear. While it has been hypothesized that a single intramolecular disulfide bond in tau leads to compact conformations that cannot form extended structure consistent with tau fibrils, there are few data to support this conjecture. In the present study we generate oxidized forms of the truncation mutant, K18, which contains all four microtubule binding repeats, and isolate the monomeric fraction, which corresponds to K18 monomers that have a single intramolecular disulfide bond. We study the aggregation propensity of the oxidized monomeric fraction and relate these data to an atomistic model of the K18 unfolded ensemble. Our results argue that the main effect of intramolecular disulfide bond formation is to preferentially stabilize conformers within the unfolded ensemble that place the aggregation-prone tau subsequences, PHF6* and PHF6, in conformations that are inconsistent with the formation of cross-β-structure. These data further our understanding of the precise structural features that retard tau aggregation.
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Affiliation(s)
| | | | - Collin M. Stultz
- From the Research Laboratory of Electronics
- the Harvard-MIT Division of Health Sciences and Technology and Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
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Yang DJ, Shi S, Yao TM, Ji LN. The Impacts of Hg(II) Tightly Binding on the Alzheimer’s Tau Construct R3: Misfolding and Aggregation. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20110133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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38
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Cooperative folding of tau peptide by coordination of group IIB metal cations during heparin-induced aggregation. Biometals 2011; 25:361-72. [DOI: 10.1007/s10534-011-9505-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 11/01/2011] [Indexed: 12/29/2022]
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39
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Furukawa Y, Kaneko K, Nukina N. Tau protein assembles into isoform- and disulfide-dependent polymorphic fibrils with distinct structural properties. J Biol Chem 2011; 286:27236-46. [PMID: 21659525 DOI: 10.1074/jbc.m111.248963] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Tauopathies are neurodegenerative diseases in which insoluble fibrillar aggregates of a microtubule-binding protein, Tau, are abnormally accumulated. Pathological Tau fibrils often exhibit structural polymorphisms that differ among phenotypically distinct tauopathies; however, a molecular mechanism to generate polymorphic Tau fibrils remains obscure. Here, we note the formation of a disulfide bond in isoforms of full-length Tau and show that the thiol-disulfide status as well as the isoform composition determines structural and morphological properties of Tau fibrils in vitro. Mainly two regions in a Tau primary sequence are found to act as structural blocks for building a protease-resistant core of Tau fibrils. Interactions among those two blocks for building a core structure depend upon the thiol-disulfide status in each isoform of Tau, which results in the formation of polymorphic fibrils with distinct structural properties. Furthermore, we have found that more diverse structures of Tau fibrils emerge through a cross-seeded fibrillation between heterologous pairs of Tau isoforms. We thus propose that isoform- and disulfide-dependent combinatorial interactions among multiple regions in a Tau sequence endow Tau fibrils with various structures, i.e. polymorphism.
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Affiliation(s)
- Yoshiaki Furukawa
- Department of Chemistry, Keio University, Yokohama, Kanagawa 223-8522, Japan.
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40
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Rosales-Corral S, Reiter RJ, Tan DX, Ortiz GG, Lopez-Armas G. Functional aspects of redox control during neuroinflammation. Antioxid Redox Signal 2010; 13:193-247. [PMID: 19951033 DOI: 10.1089/ars.2009.2629] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroinflammation is a CNS reaction to injury in which some severe pathologies, regardless of their origin, converge. The phenomenon emphasizes crosstalk between neurons and glia and reveals a complex interaction with oxidizing agents through redox sensors localized in enzymes, receptors, and transcription factors. When oxidizing pressures cause reversible molecular changes, such as minimal or transitory proinflammatory cytokine overproduction, redox couples provide a means of translating the presence of reactive oxygen or nitrogen species into useful signals in the cell. Additionally, thiol-based redox sensors convey information about localized changes in redox potential induced by physiologic or pathologic situations. They are susceptible to oxidative changes and become key events during neuroinflammation, altering the course of a signaling response or the behavior of specific transcription factors. When oxidative stress augments the pressure on the intracellular environment, the effective reduction potential of redox pairs diminishes, and cell signaling shifts toward proinflammatory and proapoptotic signals, creating a vicious cycle between oxidative stress and neuroinflammation. In addition, electrophilic compounds derived from the oxidative cascade react with key protein thiols and interfere with redox signaling. This article reviews the relevant functional aspects of redox control during the neuroinflammatory process.
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Affiliation(s)
- Sergio Rosales-Corral
- Lab. Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, División de Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO) del Instituto Mexicano del Seguro Social (IMSS) , Guadalajara, Jalisco. Mexico.
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41
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Mo ZY, Zhu YZ, Zhu HL, Fan JB, Chen J, Liang Y. Low micromolar zinc accelerates the fibrillization of human tau via bridging of Cys-291 and Cys-322. J Biol Chem 2009; 284:34648-57. [PMID: 19826005 DOI: 10.1074/jbc.m109.058883] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A hallmark of a group of neurodegenerative diseases such as Alzheimer disease is the formation of neurofibrillary tangles, which are principally composed of bundles of filaments formed by microtubule-associated protein Tau. Clarifying how natively unstructured Tau protein forms abnormal aggregates is of central importance for elucidating the etiology of these diseases. There is considerable evidence showing that zinc, as an essential element that is highly concentrated in brain, is linked to the development or progression of these diseases. Herein, by using recombinant human Tau fragment Tau(244-372) and its mutants, we have investigated the effect of zinc on the aggregation of Tau. Low micromolar concentrations of Zn(2+) dramatically accelerate fibril formation of wild-type Tau(244-372) under reducing conditions, compared with no Zn(2+). Higher concentrations of Zn(2+), however, induce wild-type Tau(244-372) to form granular aggregates in reducing conditions. Moreover, these non-fibrillar aggregates assemble into mature Tau filaments when Zn(2+) has been chelated by EDTA. Unlike wild-type Tau(244-372), low micromolar concentrations of Zn(2+) have no obvious effects on fibrillization kinetics of single mutants C291A and C322A and double mutant C291A/C322A under reducing conditions. The results from isothermal titration calorimetry show that one Zn(2+) binds to one Tau molecule via tetrahedral coordination to Cys-291 and Cys-322 as well as two histidines, with moderate, micromolar affinity. Our data demonstrate that low micromolar zinc accelerates the fibrillization of human Tau protein via bridging Cys-291 and Cys-322 in physiological reducing conditions, providing clues to understanding the relationship between zinc dyshomeostasis and the etiology of neurodegenerative diseases.
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Affiliation(s)
- Zhong-Ying Mo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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42
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Nakajima H, Amano W, Fujita A, Fukuhara A, Azuma YT, Hata F, Inui T, Takeuchi T. The active site cysteine of the proapoptotic protein glyceraldehyde-3-phosphate dehydrogenase is essential in oxidative stress-induced aggregation and cell death. J Biol Chem 2007; 282:26562-74. [PMID: 17613523 DOI: 10.1074/jbc.m704199200] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Recent studies have revealed that the redox-sensitive glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is involved in neuronal cell death that is triggered by oxidative stress. GAPDH is locally deposited in disulfide-bonded aggregates at lesion sites in certain neurodegenerative diseases. In this study, we investigated the molecular mechanism that underlies oxidative stress-induced aggregation of GAPDH and the relationship between structural abnormalities in GAPDH and cell death. Under nonreducing in vitro conditions, oxidants induced oligomerization and insoluble aggregation of GAPDH via the formation of intermolecular disulfide bonds. Because GAPDH has four cysteine residues, including the active site Cys(149), we prepared the cysteine-substituted mutants C149S, C153S, C244A, C281S, and C149S/C281S to identify which is responsible for disulfide-bonded aggregation. Whereas the aggregation levels of C281S were reduced compared with the wild-type enzyme, neither C149S nor C149S/C281S aggregated, suggesting that the active site cysteine plays an essential role. Oxidants also caused conformational changes in GAPDH concomitant with an increase in beta-sheet content; these abnormal conformations specifically led to amyloid-like fibril formation via disulfide bonds, including Cys(149). Additionally, continuous exposure of GAPDH-overexpressing HeLa cells to oxidants produced disulfide bonds in GAPDH leading to both detergent-insoluble and thioflavin-S-positive aggregates, which were associated with oxidative stress-induced cell death. Thus, oxidative stresses induce amyloid-like aggregation of GAPDH via aberrant disulfide bonds of the active site cysteine, and the formation of such abnormal aggregates promotes cell death.
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Affiliation(s)
- Hidemitsu Nakajima
- Laboratory of Veterinary Pharmacology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai City 599-8531, Japan.
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43
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Hikosou R, Kurabayashi Y, Doumoto M, Hoshitoku K, Mizushima F, Minoura K, Tomoo K, Ishida T. Effect of DNA on Filament Formation of Tau Microtubule-Binding Domain: Structural Dependence of DNA. Chem Pharm Bull (Tokyo) 2007; 55:1030-3. [PMID: 17603195 DOI: 10.1248/cpb.55.1030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To examine whether or not DNA accelerates the paired helical filament (PHF) formation of tau, the effect of various types of DNAs on filament formations of three-repeated and four-repeated microtubule-binding domains (3RMBD and 4RMBD, respectively) of tau protein was investigated by monitoring the change of thioflavin S fluorescence intensity, that is parallel to the filament formation. Consequently, the followings were clarified: 1) the structurally rigid double-stranded DNA such as poly(dG-dC) or calf thymus DNA has the high potency of promoting the filament formations of 3RMBD and 4RMBD, 2) the filament formation of 3RMBD was more promoted than that of 4RMBD, due to the intermolecular dimer formation of 3RMBD, 3) the DNA-promoted filament formations of these MBDs were temperature-dependent, and the single-stranded DNA such as poly(dA) or poly(dT) reversely protected 4RMBD from the molecular assembly at 20 degrees C. These are the first report on the function of DNA for the PHF formation of tau protein.
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Affiliation(s)
- Rie Hikosou
- Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, Osaka, Japan
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44
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Cole GM, Teter B, Frautschy SA. Neuroprotective effects of curcumin. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 595:197-212. [PMID: 17569212 PMCID: PMC2527619 DOI: 10.1007/978-0-387-46401-5_8] [Citation(s) in RCA: 312] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Neurodegenerative diseases result in the loss of functional neurons and synapses. Although future stem cell therapies offer some hope, current treatments for most of these diseases are less than adequate and ourbest hope is to prevent these devastating diseases. Neuroprotective approaches work best prior to the initiation of damage, suggesting that some safe and effective prophylaxis would be highly desirable. Curcumin has an outstanding safety profile and a number of pleiotropic actions with potential for neuroprotective efficacy, including anti-inflammatory, antioxidant, and anti-protein-aggregate activities. These can be achieved at submicromolar levels. Curcumin's dose-response curves are strongly dose dependent and often biphasic so that in vitro data need to be cautiously interpreted; many effects might not be achievable in target tissues in vivo with oral dosing. However, despite concerns about poor oral bioavailability, curcumin has at least 10 known neuroprotective actions and many of these might be realized in vivo. Indeed, accumulating cell culture and animal model data show that dietary curcumin is a strong candidate for use in the prevention or treatment of major disabling age-related neurodegenerative diseases like Alzheimer's, Parkinson's, and stroke. Promising results have already led to ongoing pilot clinical trials.
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Affiliation(s)
- Greg M Cole
- Greater Los Angeles Veterans Affairs Healthcare System, Geriatric Research, Education, and Clinic Center, Sepulveda, CA 91343, USA.
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45
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Sillen A, Leroy A, Wieruszeski JM, Loyens A, Beauvillain JC, Buée L, Landrieu I, Lippens G. Regions of tau implicated in the paired helical fragment core as defined by NMR. Chembiochem 2005; 6:1849-56. [PMID: 16196016 DOI: 10.1002/cbic.200400452] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have studied the mature Alzheimer-like fibers of tau by fluorescence and NMR spectroscopy. Assembly of the protein into paired helical filaments after incubation with heparin at 37 degrees C was verified by electron microscopy and size-exclusion chromatography. NMR spectroscopy on these mature fibers revealed different regions of residual mobility for tau: the N-terminal domain was found to maintain solution-like dynamics and was followed by a large domain of decreasing mobility; finally the core region was distinguished by a solid-like character. Heteronuclear-NOE data indicate that the decreasing mobility is due to both a slowing down of the rapid nanosecond movements and the introduction of slower movements that lead to exchange broadening. Fluorescence spectroscopy confirmed the presence of this rigid core, and some degree of protection from hydrogen exchange for those residues was observed. Hence, our data give a more precise picture of the dynamics of tau when it is integrated into mature filaments and should provide further understanding of the molecular processes that govern aggregation.
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Affiliation(s)
- Alain Sillen
- CNRS-Université de Lille 2 UMR 8525, Institut Pasteur de Lille, B.P. 245, 59019 Lille Cedex, France
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46
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Tomoo K, Yao TM, Minoura K, Hiraoka S, Sumida M, Taniguchi T, Ishida T. Possible Role of Each Repeat Structure of the Microtubule-Binding Domain of the Tau Protein in In Vitro Aggregation. ACTA ACUST UNITED AC 2005; 138:413-23. [PMID: 16272135 DOI: 10.1093/jb/mvi142] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Although one of the priorities in Alzheimer's research is to clarify the filament formation mechanism of the tau protein, it is currently unclear how it is transformed from a normal structure in a neuron. To examine which part and what structural change in the tau protein are involved in its transformation into a pathological entity, the initial in vitro self-aggregation features of each repeat peptide (R1-R4) constituting a three- or four-repeat microtubule-binding domain (3RMBD or 4RMBD) in the tau protein was investigated by measuring both the fluorescence and light scattering (LS) spectra on the same instrument, because these MBD domains constitute the core moiety of the tau paired helical filament (PHF) structure. The conformational features of the R1 and R4 peptides in trifluoroethanol were also investigated by (1)H-NMR and molecular modeling analyses and compared with those of the R2 and R3 peptides. The analyses of the LS spectra clarified (i) the self-aggregation rates of R1-R4, 3RMBD and 4RMBD at a fixed concentration (15 mM), (ii) their minimum concentrations for starting filament extension, and (iii) the concentration dependence of their self-aggregations. The fluorescence analyses showed that the R2 and R3 peptides have high self-aggregation abilities at the extension and nucleation steps, respectively, in their filament formation processes. It was shown that the R2 repeat exhibits a positive synergistic effect on the aggregation of 4RMBD. The R1 and R4 repeats, despite their weak self-aggregation abilities, are necessary for the intact PHF formation of tau MBD, whereas they exerted a negative effect on the R3-driven aggregation of 3RMBD. The conformational analyses showed the importance of the amphipathic conformational features of the R1 to R4 peptides, and the intermolecular disulfide bonding abilities of the R2 and R3 peptides for the PHF formation. On the basis of the present spectral and conformational results, the possible role of each repeat structure in the dimeric formation of MBD at the initial in vitro aggregation stage is discussed.
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Affiliation(s)
- Koji Tomoo
- Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
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47
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Cumming RC, Schubert D. Amyloid‐β induces disulfide bonding and aggregation of GAPDH in Alzheimer's disease. FASEB J 2005; 19:2060-2. [PMID: 16186172 DOI: 10.1096/fj.05-4195fje] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
GAPDH is a redox-sensitive glycolytic enzyme that also promotes apoptosis when translocated to the nucleus and associates with aggregate-prone proteins involved in neurodegenerative disorders. Recent evidence indicates that polymorphic variation within GAPDH genes is associated with an elevated risk of developing Alzheimer's disease (AD). We previously demonstrated that GAPDH readily undergoes disulfide bonding following oxidant exposure, although the consequence of disulfide bonding on GAPDH activity or function is unknown. Here we show that increased GAPDH disulfide bonding is observed in detergent-insoluble extracts from AD patient and transgenic AD mouse brain tissue compared with age-matched controls. Exposure of primary rat cortical neurons to the pro-oxidant amyloid beta peptide promotes nuclear accumulation of a disulfide-linked form of GAPDH, which becomes detergent-insoluble. Disulfide bonding leads to a reduction in GAPDH enzymatic activity and correlates with the appearance of punctate aggregate-like GAPDH staining within the cytoplasm of both oxidant-treated HT22 cells and amyloid beta-treated primary cortical neurons. Our findings suggest that disulfide bonding of GAPDH and subsequent protein aggregate formation may have relevance to the pathophysiology of AD.
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Affiliation(s)
- Robert C Cumming
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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48
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Norris EH, Giasson BI. Role of oxidative damage in protein aggregation associated with Parkinson's disease and related disorders. Antioxid Redox Signal 2005; 7:672-84. [PMID: 15890012 DOI: 10.1089/ars.2005.7.672] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Parkinson's disease, the most common movement disorder, is characterized by the loss of brainstem neurons, specifically dopaminergic neurons in the substantia nigra, as well as the accumulation of neuronal cytoplasmic filamentous proteinaceous inclusions comprised of polymerized alpha-synuclein. It was reported recently that alpha-synuclein can induce the formation of filamentous tau inclusions, which are characteristic of disorders like Alzheimer's disease and Lewy body variant of Alzheimer's disease, suggesting that a similar mechanism may exist between alpha-synuclein fibrillogenesis and tau polymerization. Pathological brain inclusions comprised of alpha-synuclein or tau proteins are associated with a spectrum of neurodegenerative disorders, and oxidative and nitrative injury has been implicated in all of these diseases. However, the role of oxidative damage in alpha-synuclein and tau polymerization and pathological inclusion formation is complex. Differences in the level, type, and temporal sequence of the oxidative alterations appear to result in both inhibitory and stimulatory effects on the fibrillogenesis of these proteins.
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Affiliation(s)
- Erin H Norris
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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49
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Minoura K, Yao TM, Tomoo K, Sumida M, Sasaki M, Taniguchi T, Ishida T. Different associational and conformational behaviors between the second and third repeat fragments in the tau microtubule-binding domain. ACTA ACUST UNITED AC 2004; 271:545-52. [PMID: 14728681 DOI: 10.1046/j.1432-1033.2003.03956.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The third repeat fragment (R3) in the four-repeat microtubule-binding domain of the water-soluble tau protein has been considered to play an essential role in the protein's filamentous assembly. To clarify the associational and conformational features that differentiate R3 from the second repeat, R2, the heparin-induced assembly profiles of these peptide fragments were monitored by the thioflavin fluorescence method and electron microscopy. The trifluoroethanol-induced reversible conformational change from a random structure to an alpha-helical structure, in an aqueous solution, was monitored by CD measurement, and the structure of R2 in trifluoroethanol solution was analyzed by a combination of two-dimensional 1H-NMR measurements and molecular modeling calculations to facilitate comparison with the structure of R3. The speed of R3 assembly was remarkably faster than that of R2, in spite of their similar amino acid sequences. The averaged NMR conformers of R2 exhibited the whole-spanning alpha-helical structure. Similar features observed in R2 and R3 conformers in trifluoroethanol were that the Leu10-Leu20/Lys20 sequence takes a helical structure with the amphipathic-like distribution of the respective side-chains, whereas the C-terminal moieties are both flexible. In contrast, a notable difference was observed at the N-terminal Val1-Lys6 sequence, namely, a helical conformation for R2 and an extended conformation for R3. These conformational behaviors would be associated with the different self-aggregation speeds and seeding reactions between R2 and R3.
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Affiliation(s)
- Katsuhiko Minoura
- Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka, Japan.
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50
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Ueberham U, Ueberham E, Gruschka H, Arendt T. Connective tissue growth factor in Alzheimer's disease. Neuroscience 2003; 116:1-6. [PMID: 12535930 DOI: 10.1016/s0306-4522(02)00670-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- U Ueberham
- Paul Flechsig Institute for Brain Research, Department of Neuroanatomy, University of Leipzig, Jahnallee 59, D-04109 Leipzig, Germany.
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