51
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Venkatramani A, Panda D. Regulation of neuronal microtubule dynamics by tau: Implications for tauopathies. Int J Biol Macromol 2019; 133:473-483. [DOI: 10.1016/j.ijbiomac.2019.04.120] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 12/13/2022]
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52
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Abstract
Tau is a microtubule-associated protein involved in the regulation of axonal microtubules in neurons. In pathological conditions, it forms fibrils that are molecular hallmarks of neurological disorders known as tauopathies. In the last 2 years, cryo-EM has given unprecedented high-resolution views of Tau in both physiological and pathological conditions. We review here these new findings and put them into the context of the knowledge about Tau before this structural breakthrough. The first structures of Tau fibrils, a molecular hallmark of Alzheimer's disease (AD), were based on fibrils from the brain of an individual with AD and, along with similar patient-derived structures, have set the gold standard for the field. Cryo-EM structures of Tau fibers in three distinct diseases, AD, Pick's disease, and chronic traumatic encephalopathy, represent the end points of Tau's molecular trajectory. We propose that the recent Tau structures may call for a re-examination of databases that link different Tau variants to various forms of dementia. We also address the question of how this structural information may link Tau's functional and pathological aspects. Because this structural information on Tau was obtained in a very short period, the new structures should be viewed in light of earlier structural observations and past and present functional data to shed additional light on Tau function and dysfunction.
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Affiliation(s)
- Guy Lippens
- From the Laboratoire d'Ingénierie des Systèmes Biologiques (LISBP), Université de Toulouse, CNRS, INRA, INSA, 135 avenue de Rangueil, 31077 Toulouse Cedex 04, France and
| | - Benoît Gigant
- the Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198 Gif-sur-Yvette Cedex, France
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53
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Melková K, Zapletal V, Narasimhan S, Jansen S, Hritz J, Škrabana R, Zweckstetter M, Ringkjøbing Jensen M, Blackledge M, Žídek L. Structure and Functions of Microtubule Associated Proteins Tau and MAP2c: Similarities and Differences. Biomolecules 2019; 9:biom9030105. [PMID: 30884818 PMCID: PMC6468450 DOI: 10.3390/biom9030105] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/09/2019] [Accepted: 03/13/2019] [Indexed: 12/16/2022] Open
Abstract
The stability and dynamics of cytoskeleton in brain nerve cells are regulated by microtubule associated proteins (MAPs), tau and MAP2. Both proteins are intrinsically disordered and involved in multiple molecular interactions important for normal physiology and pathology of chronic neurodegenerative diseases. Nuclear magnetic resonance and cryo-electron microscopy recently revealed propensities of MAPs to form transient local structures and long-range contacts in the free state, and conformations adopted in complexes with microtubules and filamentous actin, as well as in pathological aggregates. In this paper, we compare the longest, 441-residue brain isoform of tau (tau40), and a 467-residue isoform of MAP2, known as MAP2c. For both molecules, we present transient structural motifs revealed by conformational analysis of experimental data obtained for free soluble forms of the proteins. We show that many of the short sequence motifs that exhibit transient structural features are linked to functional properties, manifested by specific interactions. The transient structural motifs can be therefore classified as molecular recognition elements of tau40 and MAP2c. Their interactions are further regulated by post-translational modifications, in particular phosphorylation. The structure-function analysis also explains differences between biological activities of tau40 and MAP2c.
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Affiliation(s)
- Kateřina Melková
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
- Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
| | - Vojtěch Zapletal
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
- Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
| | - Subhash Narasimhan
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
| | - Séverine Jansen
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
| | - Jozef Hritz
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
| | - Rostislav Škrabana
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10 Bratislava, Slovakia.
- Axon Neuroscience R&D Services SE, Dvořákovo nábrežie 10, 811 02 Bratislava, Slovakia.
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Göttingen, Germany.
- Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | | | | | - Lukáš Žídek
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
- Faculty of Science, National Centre for Biomolecular Research, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic.
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54
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Inaba H, Yamamoto T, Kabir AMR, Kakugo A, Sada K, Matsuura K. Molecular Encapsulation Inside Microtubules Based on Tau-Derived Peptides. Chemistry 2018; 24:14958-14967. [PMID: 30088680 PMCID: PMC6220817 DOI: 10.1002/chem.201802617] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 11/20/2022]
Abstract
Microtubules are cytoskeletal filaments that serve as attractive scaffolds for developing nanomaterials and nanodevices because of their unique structural properties. The functionalization of the outer surface of microtubules has been established for this purpose. However, no attempts have been made to encapsulate molecules inside microtubules with 15 nm inner diameter. The encapsulation of various molecular cargos inside microtubules constitutes a new concept for nanodevice and nanocarrier applications of microtubules. Here, we developed peptide motifs for binding to the inner surface of microtubules, based on a repeat domain of the microtubule‐associated protein Tau. One of the four Tau‐derived peptides, 2N, binds to a taxol binding pocket of β‐tubulin located inside microtubules by preincubation with tubulin dimer and subsequent polymerization of the peptide‐tubulin complex. By conjugation of 2N to gold nanoparticles, encapsulation of gold nanoparticles inside microtubules was achieved. The methodology for molecular encapsulation inside microtubules by the Tau‐derived peptide is expected to advance the development of microtubule‐based nanomaterials and nanodevices.
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Affiliation(s)
- Hiroshi Inaba
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Koyama-Minami 4-101, Tottori, 680-8552, Japan.,Centre for Research on Green Sustainable Chemistry, Tottori University, Koyama-Minami 4-101, Tottori, 680-8552, Japan
| | - Takahisa Yamamoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Koyama-Minami 4-101, Tottori, 680-8552, Japan
| | - Arif Md Rashedul Kabir
- Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Akira Kakugo
- Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.,Graduate School of Chemical Sciences and Engineering, Hokkaido University, Hokkaido, 060-0810, Japan
| | - Kazuki Sada
- Faculty of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan.,Graduate School of Chemical Sciences and Engineering, Hokkaido University, Hokkaido, 060-0810, Japan
| | - Kazunori Matsuura
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Koyama-Minami 4-101, Tottori, 680-8552, Japan.,Centre for Research on Green Sustainable Chemistry, Tottori University, Koyama-Minami 4-101, Tottori, 680-8552, Japan
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55
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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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56
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Seynnaeve D, Vecchio MD, Fruhmann G, Verelst J, Cools M, Beckers J, Mulvihill DP, Winderickx J, Franssens V. Recent Insights on Alzheimer's Disease Originating from Yeast Models. Int J Mol Sci 2018; 19:E1947. [PMID: 29970827 PMCID: PMC6073265 DOI: 10.3390/ijms19071947] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 06/29/2018] [Accepted: 06/30/2018] [Indexed: 01/28/2023] Open
Abstract
In this review article, yeast model-based research advances regarding the role of Amyloid-β (Aβ), Tau and frameshift Ubiquitin UBB+1 in Alzheimer’s disease (AD) are discussed. Despite having limitations with regard to intercellular and cognitive AD aspects, these models have clearly shown their added value as complementary models for the study of the molecular aspects of these proteins, including their interplay with AD-related cellular processes such as mitochondrial dysfunction and altered proteostasis. Moreover, these yeast models have also shown their importance in translational research, e.g., in compound screenings and for AD diagnostics development. In addition to well-established Saccharomyces cerevisiae models, new upcoming Schizosaccharomyces pombe, Candida glabrata and Kluyveromyces lactis yeast models for Aβ and Tau are briefly described. Finally, traditional and more innovative research methodologies, e.g., for studying protein oligomerization/aggregation, are highlighted.
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Affiliation(s)
- David Seynnaeve
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Mara Del Vecchio
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Gernot Fruhmann
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Joke Verelst
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Melody Cools
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Jimmy Beckers
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Daniel P Mulvihill
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, Kent, UK.
| | - Joris Winderickx
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
| | - Vanessa Franssens
- Functional Biology, KU Leuven, Kasteelpark Arenberg 31, 3000 Leuven, Belgium.
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57
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Melková K, Zapletal V, Jansen S, Nomilner E, Zachrdla M, Hritz J, Nováček J, Zweckstetter M, Jensen MR, Blackledge M, Žídek L. Functionally specific binding regions of microtubule-associated protein 2c exhibit distinct conformations and dynamics. J Biol Chem 2018; 293:13297-13309. [PMID: 29925592 DOI: 10.1074/jbc.ra118.001769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 06/18/2018] [Indexed: 11/06/2022] Open
Abstract
Microtubule-associated protein 2c (MAP2c) is a 49-kDa intrinsically disordered protein regulating the dynamics of microtubules in developing neurons. MAP2c differs from its sequence homologue Tau in the pattern and kinetics of phosphorylation by cAMP-dependent protein kinase (PKA). Moreover, the mechanisms through which MAP2c interacts with its binding partners and the conformational changes and dynamics associated with these interactions remain unclear. Here, we used NMR relaxation and paramagnetic relaxation enhancement techniques to determine the dynamics and long-range interactions within MAP2c. The relaxation rates revealed large differences in flexibility of individual regions of MAP2c, with the lowest flexibility observed in the known and proposed binding sites. Quantitative conformational analyses of chemical shifts, small-angle X-ray scattering (SAXS), and paramagnetic relaxation enhancement measurements disclosed that MAP2c regions interacting with important protein partners, including Fyn tyrosine kinase, plectin, and PKA, adopt specific conformations. High populations of polyproline II and α-helices were found in Fyn- and plectin-binding sites of MAP2c, respectively. The region binding the regulatory subunit of PKA consists of two helical motifs bridged by a more extended conformation. Of note, although MAP2c and Tau did not differ substantially in their conformations in regions of high sequence identity, we found that they differ significantly in long-range interactions, dynamics, and local conformation motifs in their N-terminal domains. These results highlight that the N-terminal regions of MAP2c provide important specificity to its regulatory roles and indicate a close relationship between MAP2c's biological functions and conformational behavior.
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Affiliation(s)
- Kateřina Melková
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
| | - Vojtěch Zapletal
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
| | - Séverine Jansen
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
| | - Erik Nomilner
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
| | - Milan Zachrdla
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic.,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jozef Hritz
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic
| | - Jiří Nováček
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic
| | - Markus Zweckstetter
- the Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.,the German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Strasse 3a, 37075 Göttingen, Germany, and
| | | | | | - Lukáš Žídek
- From Masaryk University, Central European Institute of Technology, Kamenice 5, 625 00 Brno, Czech Republic, .,Masaryk University, Faculty of Science, National Centre for Biomolecular Research, Kamenice 5, 625 00 Brno, Czech Republic
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58
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Miyasaka T, Shinzaki Y, Yoshimura S, Yoshina S, Kage-Nakadai E, Mitani S, Ihara Y. Imbalanced Expression of Tau and Tubulin Induces Neuronal Dysfunction in C. elegans Models of Tauopathy. Front Neurosci 2018; 12:415. [PMID: 29973863 PMCID: PMC6019497 DOI: 10.3389/fnins.2018.00415] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/31/2018] [Indexed: 12/12/2022] Open
Abstract
Tauopathy is a type of dementia defined by the accumulation of filamentous tau inclusions in neural cells. Most types of dementia in the elderly, including Alzheimer's disease, are tauopathies. Although it is believed that tau protein abnormalities and/or the loss of its functions results in neurodegeneration and dementia, the mechanism of tauopathy remains obscure. Loss of microtubules and/or tubulin is a known consequence of tau accumulating in neurons in Alzheimer's disease. In other words, there is an excess level of tau relative to tubulin in tauopathy neurons. To test whether this imbalance of tau and tubulin expression results in the neurotoxicity of tau, we developed several transgenic C. elegans lines that express human tau at various levels in pan-neurons. These worms showed behavioral abnormalities in a tau expression-dependent manner. The knockdown of a tubulin-specific chaperon, or a subset of tubulin, led to enhanced tau toxicity even in low-expressing tau-transgenic worms that showed no abnormal behaviors. In addition, the suppression of tau expression in tubulin knockdown worms rescued neuronal dysfunction. Thus, not only the overexpression of tau but also a reduction in tubulin can trigger the neurotoxicity of tau. Tau expressed in worms was also highly phosphorylated and largely bound to tubulin dimers rather than microtubules. Relative amount of tubulin-unbound tau was increased in high-expressing tau-transgenic worms showing tau toxicity. We further demonstrated that tau aggregation was inhibited by co-incubation of purified tubulin in vitro, meaning sufficient amounts of tubulin can protect against the formation of tau inclusions. These results suggest that the expression ratio of tau to tubulin may be a determinant of the tauopathy cascade.
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Affiliation(s)
- Tomohiro Miyasaka
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Yuki Shinzaki
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Satomi Yoshimura
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
| | - Sawako Yoshina
- Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo, Japan
| | - Eriko Kage-Nakadai
- Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo, Japan
- Graduate School of Human Life Science, Osaka City University, Osaka, Japan
| | - Shohei Mitani
- Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo, Japan
| | - Yasuo Ihara
- Department of Neuropathology, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, Japan
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59
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Federico C, Gil L, Bruno F, D'Amico AG, D'Agata V, Saccone S. Phosphorylated nucleolar Tau protein is related to the neuronal in vitro differentiation. Gene 2018; 664:1-11. [PMID: 29684490 DOI: 10.1016/j.gene.2018.04.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 04/06/2018] [Accepted: 04/18/2018] [Indexed: 02/02/2023]
Abstract
Tau is a multifunctional protein, originally identified as a cytoplasmic protein associated with microtubules. It is codified by the MAPT gene, and the alternative splicing, in the neuronal cells, results in six different isoforms. Tau was subsequently observed in the cell nucleus, where its function is not yet clearly understood. Here, we studied the MAPT gene and the cellular localization of the AT8 and Tau-1 epitopes of Tau protein, in the SK-N-BE cell line, which differentiates in neuronal-like cells after retinoic acid treatment. These epitopes correspond to the phosphorylated Ser202/Thr205 and unphosphorylated Pro189/Gly207 amino acid residues, respectively, possibly involved in conformational changes of the protein. Our results demonstrated the presence of the smaller Tau isoform (352 amino acids), whose amount increases in differentiated SK-N-BE cells, with Tau-1/AT8 nuclear distribution related to the differentiation process. Tau-1 showed a spot-like nucleolar localization, in both replicative and differentiated cells, while AT8 was only detected in the differentiated cells, diffusely occupying the entire nucleolar region. Moreover, in the replicative cells exposed to actinomycin-D, AT8 and Tau-1 move to the nucleolar periphery and colocalize, in few spots, with the upstream binding transcription factor (UBTF). Our results, also obtained with lymphocytes exposed to the mitogenic compound phytohaemagglutinin, indicate the AT8 epitope of Tau as a marker of neuronal cell differentiation, whose presence in the nucleolus appears to be related to rDNA transcriptional inactivation.
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Affiliation(s)
- Concetta Federico
- Department of Biological, Geological and Environmental Sciences, University of Catania, Italy
| | - Laura Gil
- Department of Genetics, Medical School, University "Alfonso X el Sabio", Madrid, Spain
| | - Francesca Bruno
- Department of Biological, Geological and Environmental Sciences, University of Catania, Italy
| | - Agata Grazia D'Amico
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy; Department of Human Science and Promotion of Quality of Life, San Raffaele Open University of Rome, Italy
| | - Velia D'Agata
- Department of Biomedical and Biotechnological Sciences, University of Catania, Italy
| | - Salvatore Saccone
- Department of Biological, Geological and Environmental Sciences, University of Catania, Italy.
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60
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Wegmann S, Eftekharzadeh B, Tepper K, Zoltowska KM, Bennett RE, Dujardin S, Laskowski PR, MacKenzie D, Kamath T, Commins C, Vanderburg C, Roe AD, Fan Z, Molliex AM, Hernandez-Vega A, Muller D, Hyman AA, Mandelkow E, Taylor JP, Hyman BT. Tau protein liquid-liquid phase separation can initiate tau aggregation. EMBO J 2018; 37:e98049. [PMID: 29472250 PMCID: PMC5881631 DOI: 10.15252/embj.201798049] [Citation(s) in RCA: 606] [Impact Index Per Article: 101.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 11/13/2022] Open
Abstract
The transition between soluble intrinsically disordered tau protein and aggregated tau in neurofibrillary tangles in Alzheimer's disease is unknown. Here, we propose that soluble tau species can undergo liquid-liquid phase separation (LLPS) under cellular conditions and that phase-separated tau droplets can serve as an intermediate toward tau aggregate formation. We demonstrate that phosphorylated or mutant aggregation prone recombinant tau undergoes LLPS, as does high molecular weight soluble phospho-tau isolated from human Alzheimer brain. Droplet-like tau can also be observed in neurons and other cells. We found that tau droplets become gel-like in minutes, and over days start to spontaneously form thioflavin-S-positive tau aggregates that are competent of seeding cellular tau aggregation. Since analogous LLPS observations have been made for FUS, hnRNPA1, and TDP43, which aggregate in the context of amyotrophic lateral sclerosis, we suggest that LLPS represents a biophysical process with a role in multiple different neurodegenerative diseases.
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Affiliation(s)
- Susanne Wegmann
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Bahareh Eftekharzadeh
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Katharina Tepper
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Katarzyna M Zoltowska
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Rachel E Bennett
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Simon Dujardin
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Pawel R Laskowski
- Department for Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Danny MacKenzie
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Tarun Kamath
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Caitlin Commins
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Charles Vanderburg
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Allyson D Roe
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Zhanyun Fan
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Amandine M Molliex
- Department of Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | - Daniel Muller
- Department for Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Anthony A Hyman
- Department for Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Max-Planck Institute for Metabolism Research, Hamburg Outstation c/o DESY, Hamburg, Germany
- CAESAR Research Center, Bonn, Germany
| | - J Paul Taylor
- Department of Cell & Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Bradley T Hyman
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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61
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Kadavath H, Cabrales Fontela Y, Jaremko M, Jaremko Ł, Overkamp K, Biernat J, Mandelkow E, Zweckstetter M. Der Bindungsmodus eines Tau-Peptids mit Tubulin. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201712089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Harindranath Kadavath
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
- Max-Planck-Institut für Biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
| | - Yunior Cabrales Fontela
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
- Max-Planck-Institut für Biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
| | - Mariusz Jaremko
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
| | - Łukasz Jaremko
- Max-Planck-Institut für Biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
| | - Kerstin Overkamp
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
| | - Jacek Biernat
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
- CAESAR Forschungszentrum; Ludwig-Erhard-Allee 2 Bonn Deutschland
| | - Eckhard Mandelkow
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
- CAESAR Forschungszentrum; Ludwig-Erhard-Allee 2 Bonn Deutschland
| | - Markus Zweckstetter
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE); Von-Siebold Straße 3a 37075 Göttingen Deutschland
- Max-Planck-Institut für Biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
- Klinik für Neurologie; Universitätsmedizin Göttingen; Waldweg 33 37073 Göttingen Deutschland
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62
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Kadavath H, Cabrales Fontela Y, Jaremko M, Jaremko Ł, Overkamp K, Biernat J, Mandelkow E, Zweckstetter M. The Binding Mode of a Tau Peptide with Tubulin. Angew Chem Int Ed Engl 2018; 57:3246-3250. [PMID: 29314492 DOI: 10.1002/anie.201712089] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 12/15/2017] [Indexed: 11/09/2022]
Abstract
The microtubule-associated protein Tau promotes the polymerization of tubulin and modulates the function of microtubules. As a consequence of the dynamic nature of the Tau-tubulin interaction, the structural basis of this complex has remained largely elusive. By using NMR methods optimized for ligand-receptor interactions in combination with site-directed mutagenesis we demonstrate that the flanking domain downstream of the four microtubule-binding repeats of Tau binds competitively to a site on the α-tubulin surface. The binding process is complex, involves partial coupling of different interacting regions, and is modulated by phosphorylation at Y394 and S396. This study strengthens the hypothesis of an intimate relationship between Tau phosphorylation and tubulin binding and highlights the power of the INPHARMA NMR method to characterize the interaction of peptides derived from intrinsically disordered proteins with their molecular partners.
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Affiliation(s)
- Harindranath Kadavath
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany.,Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Yunior Cabrales Fontela
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany.,Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Mariusz Jaremko
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany
| | - Łukasz Jaremko
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Kerstin Overkamp
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany
| | - Jacek Biernat
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany.,CAESAR Research Center, Ludwig-Erhard-Allee 2, Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany.,CAESAR Research Center, Ludwig-Erhard-Allee 2, Bonn, Germany
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold Strasse 3a, 37075, Goettingen, Germany.,Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.,Klinik für Neurologie, Universitätsmedizin Göttingen, Waldweg 33, 37073, Göttingen, Germany
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63
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Ayers JI, Giasson BI, Borchelt DR. Prion-like Spreading in Tauopathies. Biol Psychiatry 2018; 83:337-346. [PMID: 28506438 PMCID: PMC5640465 DOI: 10.1016/j.biopsych.2017.04.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/31/2017] [Accepted: 04/04/2017] [Indexed: 10/19/2022]
Abstract
Tau is a microtubule-associated protein that functions in regulating cytoskeleton dynamics, especially in neurons. Misfolded and aggregated forms of tau produce pathological structures in a number of neurodegenerative diseases, including Alzheimer's disease (AD) and tauopathy dementias. These disorders can present with a sporadic etiology, such as in AD, or a familial etiology, such as in some cases of frontotemporal dementia with parkinsonism. Notably, the pathological features of tau pathology in these diseases can be very distinct. For example, the tau pathology in corticobasal degeneration is distinct from that of an AD patient. A wealth of evidence has emerged within the last decade to suggest that the misfolded tau in tauopathies possesses prion-like features and that such features may explain the diverse characteristics of tauopathies. The prion-like concept for tauopathies arose initially from the observation that the progressive accumulation of tau pathology as the symptoms of AD progress seemed to follow anatomically linked pathways. Subsequent studies in cell and animal models revealed that misfolded tau can propagate from cell to cell and from region to region in the brain through direct neuroanatomical connections. Studies in these cell and mouse models have demonstrated that experimentally propagated forms of misfolded tau can exist as conformationally distinct "strains" with unique biochemical, morphological, and neuropathological characteristics. This review discusses the clinical, pathological, and genetic diversity of tauopathies and the discoveries underlying the emerging view that the unique features of clinically distinct tauopathies may be a reflection of the strain of misfolded tau that propagates in each disease.
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Affiliation(s)
- Jacob I Ayers
- Department of Neuroscience, University of Florida, Gainesville, Florida; Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, Florida; McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Benoit I Giasson
- Department of Neuroscience, University of Florida, Gainesville, Florida; Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, Florida; McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - David R Borchelt
- Department of Neuroscience, University of Florida, Gainesville, Florida; Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, Florida; McKnight Brain Institute, University of Florida, Gainesville, Florida.
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64
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Gulisano W, Maugeri D, Baltrons MA, Fà M, Amato A, Palmeri A, D’Adamio L, Grassi C, Devanand D, Honig LS, Puzzo D, Arancio O. Role of Amyloid-β and Tau Proteins in Alzheimer's Disease: Confuting the Amyloid Cascade. J Alzheimers Dis 2018; 64:S611-S631. [PMID: 29865055 PMCID: PMC8371153 DOI: 10.3233/jad-179935] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The "Amyloid Cascade Hypothesis" has dominated the Alzheimer's disease (AD) field in the last 25 years. It posits that the increase of amyloid-β (Aβ) is the key event in AD that triggers tau pathology followed by neuronal death and eventually, the disease. However, therapeutic approaches aimed at decreasing Aβ levels have so far failed, and tau-based clinical trials have not yet produced positive findings. This begs the question of whether the hypothesis is correct. Here we have examined literature on the role of Aβ and tau in synaptic dysfunction, memory loss, and seeding and spreading of AD, highlighting important parallelisms between the two proteins in all of these phenomena. We discuss novel findings showing binding of both Aβ and tau oligomers to amyloid-β protein precursor (AβPP), and the requirement for the presence of this protein for both Aβ and tau to enter neurons and induce abnormal synaptic function and memory. Most importantly, we propose a novel view of AD pathogenesis in which extracellular oligomers of Aβ and tau act in parallel and upstream of AβPP. Such a view will call for a reconsideration of therapeutic approaches directed against Aβ and tau, paving the way to an increased interest toward AβPP, both for understanding the pathogenesis of the disease and elaborating new therapeutic strategies.
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Affiliation(s)
- Walter Gulisano
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Daniele Maugeri
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Marian A. Baltrons
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Biochemistry and Molecular Biology and Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Mauro Fà
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Arianna Amato
- Department of Anaesthesiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Agostino Palmeri
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Luciano D’Adamio
- Department of Pharmacology, Physiology and Neuroscience, Rutgers University, Newark, NJ, USA
| | - Claudio Grassi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - D.P. Devanand
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Lawrence S. Honig
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Daniela Puzzo
- Department of Biomedical and Biotechnological Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University, New York, NY, USA
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65
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Prezel E, Elie A, Delaroche J, Stoppin-Mellet V, Bosc C, Serre L, Fourest-Lieuvin A, Andrieux A, Vantard M, Arnal I. Tau can switch microtubule network organizations: from random networks to dynamic and stable bundles. Mol Biol Cell 2017; 29:154-165. [PMID: 29167379 PMCID: PMC5909928 DOI: 10.1091/mbc.e17-06-0429] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/08/2017] [Accepted: 11/13/2017] [Indexed: 11/11/2022] Open
Abstract
Tau is a neuronal microtubule bundler that is known to stabilize microtubules by promoting their growth and inhibiting their shrinkage. This study reveals novel mechanisms by which tau is able to switch microtubule network organizations via the differential regulation of microtubule bundling and dynamics. In neurons, microtubule networks alternate between single filaments and bundled arrays under the influence of effectors controlling their dynamics and organization. Tau is a microtubule bundler that stabilizes microtubules by stimulating growth and inhibiting shrinkage. The mechanisms by which tau organizes microtubule networks remain poorly understood. Here, we studied the self-organization of microtubules growing in the presence of tau isoforms and mutants. The results show that tau’s ability to induce stable microtubule bundles requires two hexapeptides located in its microtubule-binding domain and is modulated by its projection domain. Site-specific pseudophosphorylation of tau promotes distinct microtubule organizations: stable single microtubules, stable bundles, or dynamic bundles. Disease-related tau mutations increase the formation of highly dynamic bundles. Finally, cryo–electron microscopy experiments indicate that tau and its variants similarly change the microtubule lattice structure by increasing both the protofilament number and lattice defects. Overall, our results uncover novel phosphodependent mechanisms governing tau’s ability to trigger microtubule organization and reveal that disease-related modifications of tau promote specific microtubule organizations that may have a deleterious impact during neurodegeneration.
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Affiliation(s)
- Elea Prezel
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes
| | - Auréliane Elie
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes
| | - Julie Delaroche
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes
| | - Virginie Stoppin-Mellet
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes
| | - Christophe Bosc
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes
| | - Laurence Serre
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes.,Centre National de la Recherche Scientifique, Grenoble Institut des Neurosci ences, Institut de Biosciences et Biotechnologies de Grenoble, F-38000 Grenoble, France
| | - Anne Fourest-Lieuvin
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes.,Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biosciences et Biotechnologies de Grenoble, F-38000 Grenoble, France
| | - Annie Andrieux
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes.,Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biosciences et Biotechnologies de Grenoble, F-38000 Grenoble, France
| | - Marylin Vantard
- Inserm, U1216, Université Grenoble Alpes.,Grenoble Institut des Neurosciences, Université Grenoble Alpes.,Centre National de la Recherche Scientifique, Grenoble Institut des Neurosci ences, Institut de Biosciences et Biotechnologies de Grenoble, F-38000 Grenoble, France
| | - Isabelle Arnal
- Inserm, U1216, Université Grenoble Alpes .,Grenoble Institut des Neurosciences, Université Grenoble Alpes.,Centre National de la Recherche Scientifique, Grenoble Institut des Neurosci ences, Institut de Biosciences et Biotechnologies de Grenoble, F-38000 Grenoble, France
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66
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Rani L, Mallajosyula SS. Phosphorylation versus O-GlcNAcylation: Computational Insights into the Differential Influences of the Two Competitive Post-Translational Modifications. J Phys Chem B 2017; 121:10618-10638. [DOI: 10.1021/acs.jpcb.7b08790] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Lata Rani
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat, India - 382355
| | - Sairam S. Mallajosyula
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat, India - 382355
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67
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Ramkumar A, Jong BY, Ori-McKenney KM. ReMAPping the microtubule landscape: How phosphorylation dictates the activities of microtubule-associated proteins. Dev Dyn 2017; 247:138-155. [PMID: 28980356 DOI: 10.1002/dvdy.24599] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/11/2017] [Accepted: 09/19/2017] [Indexed: 12/12/2022] Open
Abstract
Classical microtubule-associated proteins (MAPs) were originally identified based on their co-purification with microtubules assembled from mammalian brain lysate. They have since been found to perform a range of functions involved in regulating the dynamics of the microtubule cytoskeleton. Most of these MAPs play integral roles in microtubule organization during neuronal development, microtubule remodeling during neuronal activity, and microtubule stabilization during neuronal maintenance. As a result, mutations in MAPs contribute to neurodevelopmental disorders, psychiatric conditions, and neurodegenerative diseases. MAPs are post-translationally regulated by phosphorylation depending on developmental time point and cellular context. Phosphorylation can affect the microtubule affinity, cellular localization, or overall function of a particular MAP and can thus have profound implications for neuronal health. Here we review MAP1, MAP2, MAP4, MAP6, MAP7, MAP9, tau, and DCX, and how each is regulated by phosphorylation in neuronal physiology and disease. Developmental Dynamics 247:138-155, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Amrita Ramkumar
- Department of Molecular and Cellular Biology, University of California, Davis, CA
| | - Brigette Y Jong
- Department of Molecular and Cellular Biology, University of California, Davis, CA
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68
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Piccardo P, King D, Brown D, Barron RM. Variable tau accumulation in murine models with abnormal prion protein deposits. J Neurol Sci 2017; 383:142-150. [PMID: 29246602 PMCID: PMC6381323 DOI: 10.1016/j.jns.2017.10.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 10/04/2017] [Accepted: 10/25/2017] [Indexed: 12/26/2022]
Abstract
The conversion of cellular prion protein (PrP) into a misfolded isoform is central to the development of prion diseases. However, the heterogeneous phenotypes observed in prion disease may be linked with the presence of other misfolded proteins in the brain. While hyperphosphorylated tau (p.tau) is characteristic of Alzheimer's disease (AD), p.tau is also observed in human prion diseases. To explore this association in the absence of potential effects due to aging, drug treatment, agonal stage and postmortem delay we analyzed p.tau and PrP immunopositivity in mouse models. Analyses were performed on mice inoculated with prion agents, and mice with PrP amyloid in the absence of prion disease. We observed that p.tau was consistently present in animals with prion infectivity (models that transmit disease upon serial passage). In contrast, p.tau was very rarely observed or absent in mice with PrP amyloid plaques in the absence of prion replication. These data indicate that the formation of p.tau is not linked to deposition of misfolded PrP, but suggest that the interaction between replication of infectivity and host factors regulate the formation of p.tau and may contribute to the heterogeneous phenotype of prion diseases.
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Affiliation(s)
- Pedro Piccardo
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, Scotland, United Kingdom.
| | - Declan King
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, Scotland, United Kingdom
| | - Deborah Brown
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, Scotland, United Kingdom
| | - Rona M Barron
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, Scotland, United Kingdom
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69
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Abstract
Tau is an intrinsically disordered protein with a central role in the pathology of a number of neurodegenerative diseases. Tau normally functions to stabilize neuronal microtubules, although the mechanism underlying this function is not well understood. Of note is that the interaction between tau and soluble tubulin, which has implications both in understanding tau function as well as its role in disease, is underexplored. Here we investigate the relationship between heterogeneity in tau-tubulin complexes and tau function. Specifically, we created a series of truncated and scrambled tau constructs and characterized the size and heterogeneity of the tau-tubulin complexes formed under nonpolymerizing conditions. Function of the constructs was verified by tubulin polymerization assays. We find that, surprisingly, the pseudo-repeat region of tau, which flanks the core microtubule-binding domain of tau, contributes largely to the formation of large, heterogeneous tau tubulin complexes; additional independent tubulin binding sites exist in repeats two and three of the microtubule binding domain. Of particular interest is that we find positive correlation between the size and heterogeneity of the complexes and rate of tau-promoted microtubule polymerization. We propose that tau-tubulin can be described as a "fuzzy" complex, and our results demonstrate the importance of heterogeneous complex formation in tau function. This work provides fundamental insights into the functional mechanism of tau, and more broadly underscores the relevance of heterogeneous and dynamic complexes in the functions of intrinsically disordered proteins.
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Affiliation(s)
- Xiao-Han Li
- Department of Chemistry, Yale University, New Haven, Connecticut
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
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70
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Synchrotron small-angle X-ray scattering and electron microscopy characterization of structures and forces in microtubule/Tau mixtures. Methods Cell Biol 2017; 141:155-178. [PMID: 28882300 DOI: 10.1016/bs.mcb.2017.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Tau, a neuronal protein known to bind to microtubules and thereby regulate microtubule dynamic instability, has been shown recently to not only undergo conformational transitions on the microtubule surface as a function of increasing microtubule coverage density (i.e., with increasing molar ratio of Tau to tubulin dimers) but also to mediate higher-order microtubule architectures, mimicking fascicles of microtubules found in the axon initial segment. These discoveries would not have been possible without fine structure characterization of microtubules, with and without applied osmotic pressure through the use of depletants. Herein, we discuss the two primary techniques used to elucidate the structure, phase behavior, and interactions in microtubule/Tau mixtures: transmission electron microscopy and synchrotron small-angle X-ray scattering. While the former is able to provide striking qualitative images of bundle morphologies and vacancies, the latter provides angstrom-level resolution of bundle structures and allows measurements in the presence of in situ probes, such as osmotic depletants. The presented structural characterization methods have been applied both to equilibrium mixtures, where paclitaxel is used to stabilize microtubules, and also to dissipative nonequilibrium mixtures at 37°C in the presence of GTP and lacking paclitaxel.
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71
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Guo T, Noble W, Hanger DP. Roles of tau protein in health and disease. Acta Neuropathol 2017; 133:665-704. [PMID: 28386764 PMCID: PMC5390006 DOI: 10.1007/s00401-017-1707-9] [Citation(s) in RCA: 565] [Impact Index Per Article: 80.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/26/2017] [Accepted: 03/26/2017] [Indexed: 01/18/2023]
Abstract
Tau is well established as a microtubule-associated protein in neurons. However, under pathological conditions, aberrant assembly of tau into insoluble aggregates is accompanied by synaptic dysfunction and neural cell death in a range of neurodegenerative disorders, collectively referred to as tauopathies. Recent advances in our understanding of the multiple functions and different locations of tau inside and outside neurons have revealed novel insights into its importance in a diverse range of molecular pathways including cell signalling, synaptic plasticity, and regulation of genomic stability. The present review describes the physiological and pathophysiological properties of tau and how these relate to its distribution and functions in neurons. We highlight the post-translational modifications of tau, which are pivotal in defining and modulating tau localisation and its roles in health and disease. We include discussion of other pathologically relevant changes in tau, including mutation and aggregation, and how these aspects impinge on the propensity of tau to propagate, and potentially drive neuronal loss, in diseased brain. Finally, we describe the cascade of pathological events that may be driven by tau dysfunction, including impaired axonal transport, alterations in synapse and mitochondrial function, activation of the unfolded protein response and defective protein degradation. It is important to fully understand the range of neuronal functions attributed to tau, since this will provide vital information on its involvement in the development and pathogenesis of disease. Such knowledge will enable determination of which critical molecular pathways should be targeted by potential therapeutic agents developed for the treatment of tauopathies.
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Affiliation(s)
- Tong Guo
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK
| | - Diane P Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, SE5 9NU, UK.
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72
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Trzeciakiewicz H, Tseng JH, Wander CM, Madden V, Tripathy A, Yuan CX, Cohen TJ. A Dual Pathogenic Mechanism Links Tau Acetylation to Sporadic Tauopathy. Sci Rep 2017; 7:44102. [PMID: 28287136 PMCID: PMC5347034 DOI: 10.1038/srep44102] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/02/2017] [Indexed: 12/17/2022] Open
Abstract
Tau acetylation has recently emerged as a dominant post-translational modification (PTM) in Alzheimer’s disease (AD) and related tauopathies. Mass spectrometry studies indicate that tau acetylation sites cluster within the microtubule (MT)-binding region (MTBR), suggesting acetylation could regulate both normal and pathological tau functions. Here, we combined biochemical and cell-based approaches to uncover a dual pathogenic mechanism mediated by tau acetylation. We show that acetylation specifically at residues K280/K281 impairs tau-mediated MT stabilization, and enhances the formation of fibrillar tau aggregates, highlighting both loss and gain of tau function. Full-length acetylation-mimic tau showed increased propensity to undergo seed-dependent aggregation, revealing a potential role for tau acetylation in the propagation of tau pathology. We also demonstrate that methylene blue, a reported tau aggregation inhibitor, modulates tau acetylation, a novel mechanism of action for this class of compounds. Our study identifies a potential “two-hit” mechanism in which tau acetylation disengages tau from MTs and also promotes tau aggregation. Thus, therapeutic approaches to limit tau K280/K281 acetylation could simultaneously restore MT stability and ameliorate tau pathology in AD and related tauopathies.
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Affiliation(s)
- Hanna Trzeciakiewicz
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jui-Heng Tseng
- Department of Neurology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Connor M Wander
- Department of Neurology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Victoria Madden
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Ashutosh Tripathy
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Chao-Xing Yuan
- Alexion Pharmaceuticals Inc, New Haven, Connecticut 06510, USA
| | - Todd J Cohen
- Department of Neurology, UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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73
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KrishnaKumar VG, Gupta S. Simplified method to obtain enhanced expression of tau protein from E. coli and one-step purification by direct boiling. Prep Biochem Biotechnol 2017; 47:530-538. [DOI: 10.1080/10826068.2016.1275012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- V. Guru KrishnaKumar
- Biological Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, India
| | - Sharad Gupta
- Biological Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, India
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74
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Méphon-Gaspard A, Boca M, Pioche-Durieu C, Desforges B, Burgo A, Hamon L, Piétrement O, Pastré D. Role of tau in the spatial organization of axonal microtubules: keeping parallel microtubules evenly distributed despite macromolecular crowding. Cell Mol Life Sci 2016; 73:3745-60. [PMID: 27076215 PMCID: PMC5002045 DOI: 10.1007/s00018-016-2216-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 02/07/2023]
Abstract
Opposing views have been proposed regarding the role of tau, the principal microtubule-associated protein in axons. On the one hand, tau forms cross-bridges at the interface between microtubules and induces microtubule bundling in neurons. On the other hand, tau is also considered a polymer brush which efficiently separates microtubules. In mature axons, microtubules are indeed arranged in parallel arrays and are well separated from each other. To reconcile these views, we developed a mechanistic model based on in vitro and cellular approaches combined to analytical and numerical analyses. The results indicate that tau forms long-range cross-bridges between microtubules under macromolecular crowding conditions. Tau cross-bridges prevent the redistribution of tau away from the interface between microtubules, which would have occurred in the polymer brush model. Consequently, the short-range attractive force between microtubules induced by macromolecular crowding is avoided and thus microtubules remain well separated from each other. Interestingly, in this unified model, tau diffusion on microtubules enables to keep microtubules evenly distributed in axonal sections at low tau levels.
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Affiliation(s)
- Alix Méphon-Gaspard
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Mirela Boca
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Catherine Pioche-Durieu
- UMR 8126, CNRS, Gustave Roussy Université Paris Sud, Université Paris-Saclay, Villejuif, 94805, France
| | - Bénédicte Desforges
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Andrea Burgo
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Loic Hamon
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France
| | - Olivier Piétrement
- UMR 8126, CNRS, Gustave Roussy Université Paris Sud, Université Paris-Saclay, Villejuif, 94805, France
| | - David Pastré
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR1204, Université Evry-Val d'Essonne, Evry, 91025, France.
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75
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Arendt T, Stieler JT, Holzer M. Tau and tauopathies. Brain Res Bull 2016; 126:238-292. [DOI: 10.1016/j.brainresbull.2016.08.018] [Citation(s) in RCA: 333] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 12/11/2022]
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76
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NMR Meets Tau: Insights into Its Function and Pathology. Biomolecules 2016; 6:biom6020028. [PMID: 27338491 PMCID: PMC4919923 DOI: 10.3390/biom6020028] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/02/2016] [Accepted: 05/26/2016] [Indexed: 12/21/2022] Open
Abstract
In this review, we focus on what we have learned from Nuclear Magnetic Resonance (NMR) studies on the neuronal microtubule-associated protein Tau. We consider both the mechanistic details of Tau: the tubulin relationship and its aggregation process. Phosphorylation of Tau is intimately linked to both aspects. NMR spectroscopy has depicted accurate phosphorylation patterns by different kinases, and its non-destructive character has allowed functional assays with the same samples. Finally, we will discuss other post-translational modifications of Tau and its interaction with other cellular factors in relationship to its (dys)function.
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77
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Qi H, Prabakaran S, Cantrelle FX, Chambraud B, Gunawardena J, Lippens G, Landrieu I. Characterization of Neuronal Tau Protein as a Target of Extracellular Signal-regulated Kinase. J Biol Chem 2016; 291:7742-53. [PMID: 26858248 DOI: 10.1074/jbc.m115.700914] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Indexed: 01/16/2023] Open
Abstract
Tau neuronal protein has a central role in neurodegeneration and is implicated in Alzheimer disease development. Abnormal phosphorylation of Tau impairs its interaction with other proteins and is associated with its dysregulation in pathological conditions. Molecular mechanisms leading to hyperphosphorylation of Tau in pathological conditions are unknown. Here, we characterize phosphorylation of Tau by extracellular-regulated kinase (ERK2), a mitogen-activated kinase (MAPK) that responds to extracellular signals. Analysis ofin vitrophosphorylated Tau by activated recombinant ERK2 with nuclear magnetic resonance spectroscopy (NMR) reveals phosphorylation of 15 Ser/Thr sites.In vitrophosphorylation of Tau using rat brain extract and subsequent NMR analysis identifies the same sites. Phosphorylation with rat brain extract is known to transform Tau into an Alzheimer disease-like state. Our results indicate that phosphorylation of Tau by ERK2 alone is sufficient to produce the same characteristics. We further investigate the mechanism of ERK2 phosphorylation of Tau. Kinases are known to recognize their protein substrates not only by their specificity for a targeted Ser or Thr phosphorylation site but also by binding to linear-peptide motifs called docking sites. We identify two main ERK2 docking sites in Tau sequence using NMR. Our results suggest that ERK2 dysregulation in Alzheimer disease could lead to abnormal phosphorylation of Tau resulting in the pathology of the disease.
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Affiliation(s)
- Haoling Qi
- From Lille University, CNRS UMR8576, F-59000 Lille, France
| | - Sudhakaran Prabakaran
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | | | | | - Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Guy Lippens
- From Lille University, CNRS UMR8576, F-59000 Lille, France
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78
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Sabbagh JJ, Dickey CA. The Metamorphic Nature of the Tau Protein: Dynamic Flexibility Comes at a Cost. Front Neurosci 2016; 10:3. [PMID: 26834532 PMCID: PMC4720746 DOI: 10.3389/fnins.2016.00003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 01/07/2016] [Indexed: 12/28/2022] Open
Abstract
Accumulation of the microtubule associated protein tau occurs in several neurodegenerative diseases including Alzheimer's disease (AD). The tau protein is intrinsically disordered, giving it unique structural properties that can be dynamically altered by post-translational modifications such as phosphorylation and cleavage. Over the last decade, technological advances in nuclear magnetic resonance (NMR) spectroscopy and structural modeling have permitted more in-depth insights into the nature of tau. These studies have helped elucidate how metamorphism of tau makes it ideally suited for dynamic microtubule regulation, but how it also facilitates tau self-assembly, oligomerization, and neurotoxicity. This review will focus on how the distinct structure of tau governs its function, accumulation, and toxicity as well as how other cellular factors such as molecular chaperones control these processes.
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Affiliation(s)
- Jonathan J Sabbagh
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida Tampa, FL, USA
| | - Chad A Dickey
- Department of Molecular Medicine, Byrd Alzheimer's Research Institute, University of South Florida Tampa, FL, USA
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79
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Gilley J, Ando K, Seereeram A, Rodríguez-Martín T, Pooler AM, Sturdee L, Anderton BH, Brion JP, Hanger DP, Coleman MP. Mislocalization of neuronal tau in the absence of tangle pathology in phosphomutant tau knockin mice. Neurobiol Aging 2015; 39:1-18. [PMID: 26923397 DOI: 10.1016/j.neurobiolaging.2015.11.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/25/2015] [Accepted: 11/28/2015] [Indexed: 01/22/2023]
Abstract
Hyperphosphorylation and fibrillar aggregation of the microtubule-associated protein tau are key features of Alzheimer's disease and other tauopathies. To investigate the involvement of tau phosphorylation in the pathological process, we generated a pair of complementary phosphomutant tau knockin mouse lines. One exclusively expresses phosphomimetic tau with 18 glutamate substitutions at serine and/or threonine residues in the proline-rich and first microtubule-binding domains to model hyperphosphorylation, whereas its phosphodefective counterpart has matched alanine substitutions. Consistent with expected effects of genuine phosphorylation, association of the phosphomimetic tau with microtubules and neuronal membranes is severely disrupted in vivo, whereas the phosphodefective mutations have more limited or no effect. Surprisingly, however, age-related mislocalization of tau is evident in both lines, although redistribution appears more widespread and more pronounced in the phosphomimetic tau knockin. Despite these changes, we found no biochemical or immunohistological evidence of pathological tau aggregation in mice of either line up to at least 2 years of age. These findings raise important questions about the role of tau phosphorylation in driving pathology in human tauopathies.
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Affiliation(s)
- Jonathan Gilley
- Signalling Programme, The Babraham Institute, Cambridge, UK.
| | - Kunie Ando
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculty of Medicine, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussells, Belgium
| | - Anjan Seereeram
- Department of Basic and Clinical Neuroscience (PO37), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Teresa Rodríguez-Martín
- Department of Basic and Clinical Neuroscience (PO37), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Amy M Pooler
- Department of Basic and Clinical Neuroscience (PO37), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Laura Sturdee
- Signalling Programme, The Babraham Institute, Cambridge, UK
| | - Brian H Anderton
- Department of Basic and Clinical Neuroscience (PO37), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy and Neuropathology, Faculty of Medicine, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussells, Belgium
| | - Diane P Hanger
- Department of Basic and Clinical Neuroscience (PO37), Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
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80
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Abstract
Understanding the mechanism by which tau binds to and promotes microtubule (MT) assembly as part of its native function may also provide insight into its loss of function that occurs in neurodegenerative disease. Both mechanistic and structural studies of tau have been hindered by its intrinsic disorder and highly dynamic nature. Here, we combine fluorescence correlation spectroscopy and acrylodan fluorescence screening to study the stoichiometry and structural features of tau-tubulin assemblies. Our results show that tau binds to multiple tubulin dimers, even when MT assembly is inhibited. Moreover, we observe helical structure in the repeat regions of the MT binding domain of tau in the tau-tubulin complex, reflecting partial folding upon binding. Our findings support a role for tau's intrinsic disorder in providing a flexible scaffold for binding tubulin and MTs and a disorder-to-order transition in mediating this important interaction.
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Affiliation(s)
- Xiao-Han Li
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | | | - Elizabeth Rhoades
- Department of Molecular Biophysics and Biochemistry and Department of Physics, Yale University, New Haven, Connecticut 06520, United States
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81
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Structural Impact of Tau Phosphorylation at Threonine 231. Structure 2015; 23:1448-1458. [PMID: 26165593 DOI: 10.1016/j.str.2015.06.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 11/22/2022]
Abstract
Phosphorylation of the microtubule-associated protein Tau influences the assembly and stabilization of microtubules and is deregulated in several neurodegenerative diseases. The high flexibility of Tau, however, has prevented an atomic-level description of its phosphorylation-induced structural changes. Employing an extensive set of distance and orientational restraints together with a novel ensemble calculation approach, we determined conformational ensembles of Tau fragments in the non-phosphorylated state and, when phosphorylated at T231/S235 or T231/S235/S237/S238, four important sites of phosphorylation in Alzheimer disease. Comparison of the molecular ensembles showed that phosphorylation of the regulatory T231 does not perturb the backbone conformation of the proximal microtubule-binding (225)KVAVVR(230) motif. Instead, phosphorylated T231 selectively engages in a salt bridge with R230 that can compete with the formation of intermolecular salt bridges to tubulin. Our study provides an ensemble description which will be useful for the analysis of conformational transitions in Tau and other intrinsically disordered proteins.
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82
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Tau stabilizes microtubules by binding at the interface between tubulin heterodimers. Proc Natl Acad Sci U S A 2015; 112:7501-6. [PMID: 26034266 DOI: 10.1073/pnas.1504081112] [Citation(s) in RCA: 350] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structure, dynamic behavior, and spatial organization of microtubules are regulated by microtubule-associated proteins. An important microtubule-associated protein is the protein Tau, because its microtubule interaction is impaired in the course of Alzheimer's disease and several other neurodegenerative diseases. Here, we show that Tau binds to microtubules by using small groups of evolutionary conserved residues. The binding sites are formed by residues that are essential for the pathological aggregation of Tau, suggesting competition between physiological interaction and pathogenic misfolding. Tau residues in between the microtubule-binding sites remain flexible when Tau is bound to microtubules in agreement with a highly dynamic nature of the Tau-microtubule interaction. By binding at the interface between tubulin heterodimers, Tau uses a conserved mechanism of microtubule polymerization and, thus, regulation of axonal stability and cell morphology.
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83
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Role of the Tau N-terminal region in microtubule stabilization revealed by new endogenous truncated forms. Sci Rep 2015; 5:9659. [PMID: 25974414 PMCID: PMC4431475 DOI: 10.1038/srep09659] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/13/2015] [Indexed: 12/17/2022] Open
Abstract
Tau is a central player in Alzheimer's disease (AD) and related
Tauopathies, where it is found as aggregates in degenerating neurons. Abnormal
post-translational modifications, such as truncation, are likely involved in the
pathological process. A major step forward in understanding the role of Tau
truncation would be to identify the precise cleavage sites of the several truncated
Tau fragments that are observed until now in AD brains, especially those truncated
at the N-terminus, which are less characterized than those truncated at the
C-terminus. Here, we optimized a proteomics approach and succeeded in identifying a
number of new N-terminally truncated Tau species from the human brain. We initiated
cell-based functional studies by analyzing the biochemical characteristics of two
N-terminally truncated Tau species starting at residues Met11 and Gln124
respectively. Our results show, interestingly, that the Gln124-Tau fragment displays
a stronger ability to bind and stabilize microtubules, suggesting that the Tau
N-terminal domain could play a direct role in the regulation of microtubule
stabilization. Future studies based on our new N-terminally truncated-Tau species
should improve our knowledge of the role of truncation in Tau biology as well as in
the AD pathological process.
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84
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Fontaine SN, Martin MD, Akoury E, Assimon VA, Borysov S, Nordhues BA, Sabbagh JJ, Cockman M, Gestwicki JE, Zweckstetter M, Dickey CA. The active Hsc70/tau complex can be exploited to enhance tau turnover without damaging microtubule dynamics. Hum Mol Genet 2015; 24:3971-81. [PMID: 25882706 DOI: 10.1093/hmg/ddv135] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/13/2015] [Indexed: 11/12/2022] Open
Abstract
The pathological accumulation of abnormally hyperphosphorylated and aggregated tau, a neuronal microtubule (MT)-associated protein that functions to maintain MT stability, is implicated in a number of hereditary and sporadic neurodegenerative diseases including frontotemporal dementia and Alzheimer's disease. Targeting tau for the treatment of these diseases is an area of intense interest and toward that end, modulation of cellular molecular chaperones is a potential therapeutic target. In particular, the constitutive Hsp70 isoform, Hsc70, seems highly interconnected with tau, preserving tau protein levels and synergizing with it to assemble MTs. But the relationship between tau and Hsc70, as well as the impact of this interaction in neurons and its therapeutic implications remain unknown. Using a human dominant negative Hsc70 that resembles isoform selective inhibition of this important chaperone, we found for the first time that Hsc70 activity is required to stimulate MT assembly in cells and brain. However, surprisingly, active Hsc70 also requires active tau to regulate MT assembly in vivo, suggesting that tau acts in some ways as a co-chaperone for Hsc70 to coordinate MT assembly. This was despite tau binding to Hsc70 as substrate, as determined biochemically. Moreover, we show that while chronic Hsc70 inhibition damaged MT dynamics, intermittent treatment with a small molecule Hsp70 inhibitor lowered tau in brain tissue without disrupting MT integrity. Thus, in tauopathies, where MT injury would be detrimental to neurons, the unique relationship of tau with the Hsc70 machinery can be exploited to deplete tau levels without damaging MT networks.
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Affiliation(s)
- Sarah N Fontaine
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA, James A. Haley Veteran's Hospital, 13000 Bruce B. Downs Blvd, Tampa, FL 33612, USA
| | - Mackenzie D Martin
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Elias Akoury
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany, German Center for Neurodegenerative Diseases (DZNE), Göttingen 37077, Germany, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center, Göttingen 37073, Germany and
| | - Victoria A Assimon
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, USA
| | - Sergiy Borysov
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Bryce A Nordhues
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA, James A. Haley Veteran's Hospital, 13000 Bruce B. Downs Blvd, Tampa, FL 33612, USA
| | - Jonathan J Sabbagh
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA, James A. Haley Veteran's Hospital, 13000 Bruce B. Downs Blvd, Tampa, FL 33612, USA
| | - Matt Cockman
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA
| | - Jason E Gestwicki
- Institute for Neurodegenerative Disease, University of California at San Francisco, San Francisco, CA 94158, USA
| | - Markus Zweckstetter
- Department for NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany, German Center for Neurodegenerative Diseases (DZNE), Göttingen 37077, Germany, Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center, Göttingen 37073, Germany and
| | - Chad A Dickey
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL 33613, USA, James A. Haley Veteran's Hospital, 13000 Bruce B. Downs Blvd, Tampa, FL 33612, USA,
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85
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Fontaine SN, Sabbagh JJ, Baker J, Martinez-Licha CR, Darling A, Dickey CA. Cellular factors modulating the mechanism of tau protein aggregation. Cell Mol Life Sci 2015; 72:1863-79. [PMID: 25666877 DOI: 10.1007/s00018-015-1839-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/18/2014] [Accepted: 01/13/2015] [Indexed: 01/12/2023]
Abstract
Pathological accumulation of the microtubule-associated protein tau, in the form of neurofibrillary tangles, is a major hallmark of Alzheimer's disease, the most prevalent neurodegenerative condition worldwide. In addition to Alzheimer's disease, a number of neurodegenerative diseases, called tauopathies, are characterized by the accumulation of aggregated tau in a variety of brain regions. While tau normally plays an important role in stabilizing the microtubule network of the cytoskeleton, its dissociation from microtubules and eventual aggregation into pathological deposits is an area of intense focus for therapeutic development. Here we discuss the known cellular factors that affect tau aggregation, from post-translational modifications to molecular chaperones.
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Affiliation(s)
- Sarah N Fontaine
- Department of Molecular Medicine, College of Medicine, Byrd Alzheimer's Institute, University of South Florida, Tampa, FL, 33613, USA
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86
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Qi H, Cantrelle FX, Benhelli-Mokrani H, Smet-Nocca C, Buée L, Lippens G, Bonnefoy E, Galas MC, Landrieu I. Nuclear magnetic resonance spectroscopy characterization of interaction of Tau with DNA and its regulation by phosphorylation. Biochemistry 2015; 54:1525-33. [PMID: 25623359 DOI: 10.1021/bi5014613] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The capacity of endogenous Tau to bind DNA has been recently identified in neurons under physiological or oxidative stress conditions. Characterization of the protein domains involved in Tau-DNA complex formation is an essential first step in clarifying the contribution of Tau-DNA interactions to neurological biological processes. To identify the amino acid residues involved in the interaction of Tau with oligonucleotides, we have characterized a Tau-DNA complex using nuclear magnetic resonance spectroscopy. Interaction of an AT-rich or GC-rich 22 bp oligonucleotide with Tau showed multiple points of anchoring along the intrinsically disordered Tau protein. The main sites of contact characterized here correspond to the second half of the proline-rich domain (PRD) of Tau and the R2 repeat in the microtubule binding domain. This latter interaction site includes the PHF6* sequence known to govern Tau aggregation. The characterization was pursued by studying the binding of phosphorylated forms of Tau, displaying multiple phosphorylation sites mainly in the PRD, to the same oligonucleotide. No interaction of phospho-Tau with the oligonucleotide was detected, suggesting that pathological Tau phosphorylation could affect the physiological function of Tau mediated by DNA binding.
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Affiliation(s)
- Haoling Qi
- UMR8576 CNRS-Lille University , 59655 Villeneuve d'Ascq, France
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87
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Barman A, Hamelberg D. Loss of intramolecular electrostatic interactions and limited conformational ensemble may promote self-association ofcis-tau peptide. Proteins 2015; 83:436-44. [DOI: 10.1002/prot.24740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/07/2014] [Accepted: 11/26/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Arghya Barman
- Department of Chemistry and the Center for Biotechnology and Drug Design; Georgia State University; Atlanta Georgia 30302-4098
| | - Donald Hamelberg
- Department of Chemistry and the Center for Biotechnology and Drug Design; Georgia State University; Atlanta Georgia 30302-4098
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88
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Hashi Y, Kawai G, Kotani S. Microtubule-associated protein (MAP) 4 interacts with microtubules in an intrinsically disordered manner. Biosci Biotechnol Biochem 2014; 78:1864-70. [DOI: 10.1080/09168451.2014.940836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Abstract
We previously used nuclear magnetic resonance (NMR) to analyze the structure of a synthetic tricosapeptide corresponding to an active site of microtubule-associated protein 4 (MAP4). To further the structural analysis, we have constructed a minimal active domain fragment of MAP4, encompassing the entire active site, and obtained its NMR spectra. The secondary structure prediction using partially assigned NMR data suggested that the fragment is largely unfolded. Two other independent techniques also demonstrated its unfolded nature, indicating that MAP4 belongs to the class of intrinsically disordered proteins (IDPs). The NMR spectra of the fragment-microtubule mixture revealed that the fragment binds to the microtubule using multiple binding sites, apparently contradicting our previous quantitative studies. Given that MAP4 is intrinsically disordered, we propose a mechanism in which any one of the binding sites is active at a time, which is one of the typical interaction mechanisms proposed for IDPs.
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Affiliation(s)
- Yurika Hashi
- Faculty of Science, Department of Biological Sciences, Kanagawa University, Hiratsuka, Japan
| | - Gota Kawai
- Faculty of Engineering, Department of Life and Environmental Sciences, Chiba Institute of Technology, Narashino, Japan
| | - Susumu Kotani
- Faculty of Science, Department of Biological Sciences, Kanagawa University, Hiratsuka, Japan
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89
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Henriques AG, Oliveira JM, Carvalho LP, da Cruz E Silva OAB. Aβ Influences Cytoskeletal Signaling Cascades with Consequences to Alzheimer's Disease. Mol Neurobiol 2014; 52:1391-1407. [PMID: 25344315 DOI: 10.1007/s12035-014-8913-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/28/2014] [Indexed: 01/16/2023]
Abstract
Abnormal signal transduction events can impact upon the cytoskeleton, affecting the actin and microtubule networks with direct relevance to Alzheimer's disease (AD). Cytoskeletal anomalies, in turn, promote atypical neuronal responses, with consequences for cellular organization and function. Neuronal cytoskeletal modifications in AD include neurofibrillary tangles, which result from aggregates of hyperphosphorylated tau protein. The latter is a microtubule (MT)-binding protein, whose abnormal phosphorylation leads to MT instability and consequently provokes irregularities in the neuronal trafficking pathways. Early stages of AD are also characterized by synaptic dysfunction and loss of dendritic spines, which correlate with cognitive deficit and impaired brain function. Actin dynamics has a prominent role in maintaining spine plasticity and integrity, thus providing the basis for memory and learning processes. Hence, factors that disrupt both actin and MT network dynamics will compromise neuronal function and survival. The peptide Aβ is the major component of senile plaques and has been described as a pivotal mediator of neuronal dystrophy and synaptic loss in AD. Here, we review Aβ-mediated effects on both MT and actin networks and focus on the relevance of the elicited cytoskeletal signaling events targeted in AD pathology.
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Affiliation(s)
- Ana Gabriela Henriques
- Laboratório de Neurociências e Sinalização, Centro de Biologia Celular, SACS, Universidade de Aveiro, 3810-193, Aveiro, Portugal
| | - Joana Machado Oliveira
- Laboratório de Neurociências e Sinalização, Centro de Biologia Celular, SACS, Universidade de Aveiro, 3810-193, Aveiro, Portugal
| | - Liliana Patrícia Carvalho
- Laboratório de Neurociências e Sinalização, Centro de Biologia Celular, SACS, Universidade de Aveiro, 3810-193, Aveiro, Portugal
| | - Odete A B da Cruz E Silva
- Laboratório de Neurociências e Sinalização, Centro de Biologia Celular, SACS, Universidade de Aveiro, 3810-193, Aveiro, Portugal.
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90
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Lysine methylation is an endogenous post-translational modification of tau protein in human brain and a modulator of aggregation propensity. Biochem J 2014; 462:77-88. [PMID: 24869773 DOI: 10.1042/bj20140372] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In Alzheimer's disease, the microtubule-associated protein tau dissociates from the neuronal cytoskeleton and aggregates to form cytoplasmic inclusions. Although hyperphosphorylation of tau serine and threonine residues is an established trigger of tau misfunction and aggregation, tau modifications extend to lysine residues as well, raising the possibility that different modification signatures depress or promote aggregation propensity depending on site occupancy. To identify lysine residue modifications associated with normal tau function, soluble tau proteins isolated from four cognitively normal human brains were characterized by MS methods. The major detectable lysine modification was found to be methylation, which appeared in the form of mono- and di-methyl lysine residues distributed among at least 11 sites. Unlike tau phosphorylation sites, the frequency of lysine methylation was highest in the microtubule-binding repeat region that mediates both microtubule binding and homotypic interactions. When purified recombinant human tau was modified in vitro through reductive methylation, its ability to promote tubulin polymerization was retained, whereas its aggregation propensity was greatly attenuated at both nucleation and extension steps. These data establish lysine methylation as part of the normal tau post-translational modification signature in human brain, and suggest that it can function in part to protect against pathological tau aggregation.
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91
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Gigant B, Landrieu I, Fauquant C, Barbier P, Huvent I, Wieruszeski JM, Knossow M, Lippens G. Mechanism of Tau-promoted microtubule assembly as probed by NMR spectroscopy. J Am Chem Soc 2014; 136:12615-23. [PMID: 25162583 DOI: 10.1021/ja504864m] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Determining the molecular mechanism of the neuronal Tau protein in the tubulin heterodimer assembly has been a challenge owing to the dynamic character of the complex and the large size of microtubules. We use here defined constructs comprising one or two tubulin heterodimers to characterize their association with a functional fragment of Tau, named TauF4. TauF4 binds with high affinities to the tubulin heterodimer complexes, but NMR spectroscopy shows that it remains highly dynamic, partly because of the interaction with the acidic C-terminal tails of the tubulin monomers. When bound to a single tubulin heterodimer, TauF4 is characterized by an overhanging peptide corresponding to the first of the four microtubule binding repeats of Tau. This peptide becomes immobilized in the complex with two longitudinally associated tubulin heterodimers. The longitudinal associations are favored by the fragment and contribute to Tau's functional role in microtubule assembly.
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Affiliation(s)
- Benoît Gigant
- Laboratoire d'Enzymologie et Biochimie Structurales, Centre de Recherche de Gif, Centre National de la Recherche Scientifique , 91198 Gif sur Yvette, France
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92
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Scholz T, Mandelkow E. Transport and diffusion of Tau protein in neurons. Cell Mol Life Sci 2014; 71:3139-50. [PMID: 24687422 PMCID: PMC11113808 DOI: 10.1007/s00018-014-1610-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/20/2014] [Accepted: 03/13/2014] [Indexed: 12/11/2022]
Abstract
In highly polarized and elongated cells such as neurons, Tau protein must enter and move down the axon to fulfill its biological task of stabilizing axonal microtubules. Therefore, cellular systems for distributing Tau molecules are needed. This review discusses different mechanisms that have been proposed to contribute to the dispersion of Tau molecules in neurons. They include (1) directed transport along microtubules as cargo of tubulin complexes and/or motor proteins, (2) diffusion, either through the cytosolic space or along microtubules, and (3) mRNA-based mechanisms such as transport of Tau mRNA into axons and local translation. Diffusion along the microtubule lattice or through the cytosol appear to be the major mechanisms for axonal distribution of Tau protein in the short-to-intermediate range over distances of up to a millimetre. The high diffusion coefficients ensure that Tau can distribute evenly throughout the axonal volume as well as along microtubules. Motor protein-dependent transport of Tau dominates over longer distances and time scales. At low near-physiological levels, Tau is co-transported along with short microtubules from cell bodies into axons by cytoplasmic dynein and kinesin family members at rates of slow axonal transport.
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Affiliation(s)
- Tim Scholz
- Institute for Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany,
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93
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C-terminal region of MAP7 domain containing protein 3 (MAP7D3) promotes microtubule polymerization by binding at the C-terminal tail of tubulin. PLoS One 2014; 9:e99539. [PMID: 24927501 PMCID: PMC4057234 DOI: 10.1371/journal.pone.0099539] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/16/2014] [Indexed: 12/24/2022] Open
Abstract
MAP7 domain containing protein 3 (MAP7D3), a newly identified microtubule associated protein, has been shown to promote microtubule assembly and stability. Its microtubule binding region has been reported to consist of two coiled coil motifs located at the N-terminus. It possesses a MAP7 domain near the C-terminus and belongs to the microtubule associated protein 7 (MAP7) family. The MAP7 domain of MAP7 protein has been shown to bind to kinesin-1; however, the role of MAP7 domain in MAP7D3 remains unknown. Based on the bioinformatics analysis of MAP7D3, we hypothesized that the MAP7 domain of MAP7D3 may have microtubule binding activity. Indeed, we found that MAP7 domain of MAP7D3 bound to microtubules as well as enhanced the assembly of microtubules in vitro. Interestingly, a longer fragment MDCT that contained the MAP7 domain (MD) with the C-terminal tail (CT) of the protein promoted microtubule polymerization to a greater extent than MD and CT individually. MDCT stabilized microtubules against dilution induced disassembly. MDCT bound to reconstituted microtubules with an apparent dissociation constant of 3.0±0.5 µM. An immunostaining experiment showed that MDCT localized along the length of the preassembled microtubules. Competition experiments with tau indicated that MDCT shares its binding site on microtubules with tau. Further, we present evidence indicating that MDCT binds to the C-terminal tail of tubulin. In addition, MDCT could bind to tubulin in HeLa cell extract. Here, we report a microtubule binding region in the C-terminal region of MAP7D3 that may have a role in regulating microtubule assembly dynamics.
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94
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Abstract
Tau is a microtubule binding protein that forms pathological aggregates in the brain in Alzheimer's disease and other tauopathies. Disease etiology is thought to arise from loss of native interactions between tau and microtubules, as well as from gain of toxicity tied to tau aggregation, although neither mechanism is well understood. Here we investigate the link between function and disease using disease-associated and disease-motivated mutants of tau. We find that mutations to highly conserved proline residues in repeats 2 and 3 of the microtubule binding domain have differential effects on tau binding to tubulin and the capacity of tau to enhance tubulin polymerization. Notably, mutations to these residues result in an increased affinity for tubulin dimers while having a negligible effect on binding to stabilized microtubules. We measure conformational changes in tau on binding to tubulin that provide a structural framework for the observed altered affinity and function. Additionally, we find that these mutations do not necessarily enhance aggregation, which could have important implications for tau therapeutic strategies that focus solely on searching for tau aggregation inhibitors. We propose a model that describes tau binding to tubulin dimers and a mechanism by which disease-relevant alterations to tau impact its function. Together, these results draw attention to the interaction between tau and free tubulin as playing an important role in mechanisms of tau pathology.
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95
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Lyons AJ, Gandhi NS, Mancera RL. Molecular dynamics simulation of the phosphorylation-induced conformational changes of a tau peptide fragment. Proteins 2014; 82:1907-23. [PMID: 24577753 DOI: 10.1002/prot.24544] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 02/05/2014] [Accepted: 02/11/2014] [Indexed: 11/09/2022]
Abstract
Aggregation of the microtubule associated protein tau (MAPT) within neurons of the brain is the leading cause of tauopathies such as Alzheimer's disease. MAPT is a phospho-protein that is selectively phosphorylated by a number of kinases in vivo to perform its biological function. However, it may become pathogenically hyperphosphorylated, causing aggregation into paired helical filaments and neurofibrillary tangles. The phosphorylation induced conformational change on a peptide of MAPT (htau225-250) was investigated by performing molecular dynamics simulations with different phosphorylation patterns of the peptide (pThr231 and/or pSer235) in different simulation conditions to determine the effect of ionic strength and phosphate charge. All phosphorylation patterns were found to disrupt a nascent terminal β-sheet pattern (226VAVVR230 and 244QTAPVP249), replacing it with a range of structures. The double pThr231/pSer235 phosphorylation pattern at experimental ionic strength resulted in the best agreement with NMR structural characterization, with the observation of a transient α-helix (239AKSRLQT245). PPII helical conformations were only found sporadically throughout the simulations.
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Affiliation(s)
- Albert J Lyons
- School of Biomedical Sciences, CHIRI Biosciences, Curtin University, Perth, 6845, Western Australia
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96
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Oxidative stress and metabolic syndrome: cause or consequence of Alzheimer's disease? OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:497802. [PMID: 24683436 PMCID: PMC3941786 DOI: 10.1155/2014/497802] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 12/02/2013] [Accepted: 12/18/2013] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is a major neurodegenerative disease affecting the elderly. Clinically, it is characterized by a progressive loss of memory and cognitive function. Neuropathologically, it is characterized by the presence of extracellular β-amyloid (Aβ) deposited as neuritic plaques (NP) and neurofibrillary tangles (NFT) made of abnormal and hyperphosphorylated tau protein. These lesions are capable of generating the neuronal damage that leads to cell death and cognitive failure through the generation of reactive oxygen species (ROS). Evidence indicates the critical role of Aβ metabolism in prompting the oxidative stress observed in AD patients. However, it has also been proposed that oxidative damage precedes the onset of clinical and pathological AD symptoms, including amyloid-β deposition, neurofibrillary tangle formation, vascular malfunction, metabolic syndrome, and cognitive decline. This paper provides a brief description of the three main proteins associated with the development of the disease (Aβ, tau, and ApoE) and describes their role in the generation of oxidative stress. Finally, we describe the mitochondrial alterations that are generated by Aβ and examine the relationship of vascular damage which is a potential prognostic tool of metabolic syndrome. In addition, new therapeutic approaches targeting ROS sources and metabolic support were reported.
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97
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Clavaguera F, Lavenir I, Falcon B, Frank S, Goedert M, Tolnay M. "Prion-like" templated misfolding in tauopathies. Brain Pathol 2013; 23:342-9. [PMID: 23587140 DOI: 10.1111/bpa.12044] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 02/11/2013] [Indexed: 12/20/2022] Open
Abstract
The soluble microtubule-associated protein tau forms hyperphosphorylated, insoluble and filamentous inclusions in a number of neurodegenerative diseases referred to as "tauopathies." In Alzheimer's disease, tau pathology develops in a stereotypical manner, with the first lesions appearing in the locus coeruleus and entorhinal cortex, from where they appear to spread to the hippocampus and neocortex. Propagation of tau pathology is also a characteristic of argyrophilic grain disease, where the tau lesions spread throughout the limbic system. Significantly, isoform composition and morphology of tau filaments can differ between tauopathies, suggesting the existence of distinct tau strains. Extensive experimental findings indicate that prion-like mechanisms underly the pathogenesis of tauopathies.
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Affiliation(s)
- Florence Clavaguera
- Department of Neuropathology, Institute of Pathology, University Hospital Basel, Basel, Switzerland
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98
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Zaichick SV, Bohannon KP, Hughes A, Sollars PJ, Pickard GE, Smith GA. The herpesvirus VP1/2 protein is an effector of dynein-mediated capsid transport and neuroinvasion. Cell Host Microbe 2013; 13:193-203. [PMID: 23414759 DOI: 10.1016/j.chom.2013.01.009] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 11/13/2012] [Accepted: 01/11/2013] [Indexed: 12/23/2022]
Abstract
Microtubule transport of herpesvirus capsids from the cell periphery to the nucleus is imperative for viral replication and, in the case of many alphaherpesviruses, transmission into the nervous system. Using the neuroinvasive herpesvirus, pseudorabies virus (PRV), we show that the viral protein 1/2 (VP1/2) tegument protein associates with the dynein/dynactin microtubule motor complex and promotes retrograde microtubule transport of PRV capsids. Functional activation of VP1/2 requires binding to the capsid protein pUL25 or removal of the capsid-binding domain. A proline-rich sequence within VP1/2 is required for the efficient interaction with the dynein/dynactin microtubule motor complex as well as for PRV virulence and retrograde axon transport in vivo. Additionally, in the absence of infection, functionally active VP1/2 is sufficient to move large surrogate cargoes via the dynein/dynactin microtubule motor complex. Thus, VP1/2 tethers PRV capsids to dynein/dynactin to enhance microtubule transport, neuroinvasion, and pathogenesis.
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Affiliation(s)
- Sofia V Zaichick
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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99
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Ramachandran G, Udgaonkar JB. Mechanistic studies unravel the complexity inherent in tau aggregation leading to Alzheimer's disease and the tauopathies. Biochemistry 2013; 52:4107-26. [PMID: 23721410 DOI: 10.1021/bi400209z] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aggregation of the protein tau into amyloid fibrils is known to be involved in the causation of the neurodegenerative tauopathies and the progression of cognitive decline in Alzheimer's disease. This review surveys the mechanism of tau aggregation with special emphasis on the information obtained from biochemical and biophysical studies. First, tau is described from a structure-function perspective. Subsequently, the connection of tau to neurodegeneration is explained, and a description of the tau amyloid fibril is provided. Lastly, studies of the mechanism of tau fibril formation are reviewed, and the physiological significance of these studies with reference to how they can clarify many aspects of disease progression is described. The aim of this review is to underscore how mechanistic studies reveal the complexity of the tau fibril formation pathway and the plethora of species populated on or off the pathway of aggregation, and how this information can be beneficial in the design of inhibitors or drugs that ameliorate neurodegeneration.
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Affiliation(s)
- Gayathri Ramachandran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research , Bangalore 560065, India
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100
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Argyrophilic grain disease differs from other tauopathies by lacking tau acetylation. Acta Neuropathol 2013; 125:581-93. [PMID: 23371364 DOI: 10.1007/s00401-013-1080-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/10/2013] [Indexed: 12/11/2022]
Abstract
Post-translational modifications play a key role in tau protein aggregation and related neurodegeneration. Because hyperphosphorylation alone does not necessarily cause tau aggregation, other post-translational modifications have been recently explored. Tau acetylation promotes aggregation and inhibits tau's ability to stabilize microtubules. Recent studies have shown co-localization of acetylated and phosphorylated tau in AD and some 4R tauopathies. We developed a novel monoclonal antibody against acetylated tau at lysine residue 274, which recognizes both 3R and 4R tau, and used immunohistochemistry and immunofluorescence to probe 22 cases, including AD and another eight familial or sporadic tauopathies. Acetylated tau was identified in all tauopathies except argyrophilic grain disease (AGD). AGD is an age-associated, common but atypical 4R tauopathy, not always associated with clinical progression. Pathologically, AGD is characterized by neuropil grains, pre-neurofibrillary tangles, and oligodendroglial coiled bodies, all recognized by phospho-tau antibodies. The lack of acetylated tau in these inclusions suggests that AGD represents a distinctive tauopathy. Our data converge with previous findings to raise the hypothesis that AGD could play a protective role against the spread of AD-related tau pathology. Tau acetylation as a key modification for the propagation tau toxicity deserves further investigation.
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