Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies
Ubiquitin, a protein modifier that regulates diverse essential cellular processes, is also a component of the protein inclusions characteristic of many neurodegenerative disorders. In Alzheimer’s disease, the microtubule associated tau protein accumulates within damaged neurons in the form of cross-...
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MDPI AG
2020-06-01
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author | Francesca Munari Carlo Giorgio Barracchia Francesca Parolini Roberto Tira Luigi Bubacco Michael Assfalg Mariapina D’Onofrio |
author_facet | Francesca Munari Carlo Giorgio Barracchia Francesca Parolini Roberto Tira Luigi Bubacco Michael Assfalg Mariapina D’Onofrio |
author_sort | Francesca Munari |
collection | DOAJ |
description | Ubiquitin, a protein modifier that regulates diverse essential cellular processes, is also a component of the protein inclusions characteristic of many neurodegenerative disorders. In Alzheimer’s disease, the microtubule associated tau protein accumulates within damaged neurons in the form of cross-beta structured filaments. Both mono- and polyubiquitin were found linked to several lysine residues belonging to the region of tau protein that forms the structured core of the filaments. Thus, besides priming the substrate protein for proteasomal degradation, ubiquitin could also contribute to the assembly and stabilization of tau protein filaments. To advance our understanding of the impact of ubiquitination on tau protein aggregation and function, we applied disulfide-coupling chemistry to modify tau protein at position 353 with Lys48- or Lys63-linked di-ubiquitin, two representative polyubiquitin chains that differ in topology and structure. Aggregation kinetics experiments performed on these conjugates reveal that di-ubiquitination retards filament formation and perturbs the fibril elongation rate more than mono-ubiquitination. We further show that di-ubiquitination modulates tau-mediated microtubule assembly. The effects on tau protein aggregation and microtubule polymerization are essentially independent from polyubiquitin chain topology. Altogether, our findings provide novel insight into the consequences of ubiquitination on the functional activity and disease-related behavior of tau protein. |
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issn | 1661-6596 1422-0067 |
language | English |
last_indexed | 2024-03-10T19:00:19Z |
publishDate | 2020-06-01 |
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series | International Journal of Molecular Sciences |
spelling | doaj.art-7f249eba4ff444bc8e0e9d87a528c6462023-11-20T04:29:01ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672020-06-012112440010.3390/ijms21124400Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation StudiesFrancesca Munari0Carlo Giorgio Barracchia1Francesca Parolini2Roberto Tira3Luigi Bubacco4Michael Assfalg5Mariapina D’Onofrio6Department of Biotechnology, University of Verona, 37128 Verona, ItalyDepartment of Biotechnology, University of Verona, 37128 Verona, ItalyDepartment of Biotechnology, University of Verona, 37128 Verona, ItalyDepartment of Biotechnology, University of Verona, 37128 Verona, ItalyDepartment of Biology, University of Padova, 35121 Padova, ItalyDepartment of Biotechnology, University of Verona, 37128 Verona, ItalyDepartment of Biotechnology, University of Verona, 37128 Verona, ItalyUbiquitin, a protein modifier that regulates diverse essential cellular processes, is also a component of the protein inclusions characteristic of many neurodegenerative disorders. In Alzheimer’s disease, the microtubule associated tau protein accumulates within damaged neurons in the form of cross-beta structured filaments. Both mono- and polyubiquitin were found linked to several lysine residues belonging to the region of tau protein that forms the structured core of the filaments. Thus, besides priming the substrate protein for proteasomal degradation, ubiquitin could also contribute to the assembly and stabilization of tau protein filaments. To advance our understanding of the impact of ubiquitination on tau protein aggregation and function, we applied disulfide-coupling chemistry to modify tau protein at position 353 with Lys48- or Lys63-linked di-ubiquitin, two representative polyubiquitin chains that differ in topology and structure. Aggregation kinetics experiments performed on these conjugates reveal that di-ubiquitination retards filament formation and perturbs the fibril elongation rate more than mono-ubiquitination. We further show that di-ubiquitination modulates tau-mediated microtubule assembly. The effects on tau protein aggregation and microtubule polymerization are essentially independent from polyubiquitin chain topology. Altogether, our findings provide novel insight into the consequences of ubiquitination on the functional activity and disease-related behavior of tau protein.https://www.mdpi.com/1422-0067/21/12/4400tau proteinubiquitinationsemisynthesisdisulfide-couplingpolyubiquitinfibrils |
spellingShingle | Francesca Munari Carlo Giorgio Barracchia Francesca Parolini Roberto Tira Luigi Bubacco Michael Assfalg Mariapina D’Onofrio Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies International Journal of Molecular Sciences tau protein ubiquitination semisynthesis disulfide-coupling polyubiquitin fibrils |
title | Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies |
title_full | Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies |
title_fullStr | Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies |
title_full_unstemmed | Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies |
title_short | Semisynthetic Modification of Tau Protein with Di-Ubiquitin Chains for Aggregation Studies |
title_sort | semisynthetic modification of tau protein with di ubiquitin chains for aggregation studies |
topic | tau protein ubiquitination semisynthesis disulfide-coupling polyubiquitin fibrils |
url | https://www.mdpi.com/1422-0067/21/12/4400 |
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