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FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments
Tau aggregation into amyloid fibers based on the cross-beta structure is a hallmark of several Tauopathies, including Alzheimer Disease (AD). Trans-cellular propagation of Tau with pathological conformation has been suggested as a key disease mechanism. This is thought to cause the spreading of Tau...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7364478/ https://www.ncbi.nlm.nih.gov/pubmed/32677995 http://dx.doi.org/10.1186/s13024-020-00389-1 |
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author | Kaniyappan, Senthilvelrajan Tepper, Katharina Biernat, Jacek Chandupatla, Ram Reddy Hübschmann, Sabrina Irsen, Stephan Bicher, Sandra Klatt, Christoph Mandelkow, Eva-Maria Mandelkow, Eckhard |
author_facet | Kaniyappan, Senthilvelrajan Tepper, Katharina Biernat, Jacek Chandupatla, Ram Reddy Hübschmann, Sabrina Irsen, Stephan Bicher, Sandra Klatt, Christoph Mandelkow, Eva-Maria Mandelkow, Eckhard |
author_sort | Kaniyappan, Senthilvelrajan |
collection | PubMed |
description | Tau aggregation into amyloid fibers based on the cross-beta structure is a hallmark of several Tauopathies, including Alzheimer Disease (AD). Trans-cellular propagation of Tau with pathological conformation has been suggested as a key disease mechanism. This is thought to cause the spreading of Tau pathology in AD by templated conversion of naive Tau in recipient cells into a pathological state, followed by assembly of pathological Tau fibers, similar to the mechanism of nucleated polymerization proposed for prion pathogenesis. In cell cultures, the process is often monitored by a FRET assay where the recipient cell expresses the Tau repeat domain (Tau(RD)) with a pro-aggregant mutation, fused to GFP-based FRET pairs. Since the size of the reporter GFP (barrel of ~ 3 nm × 4 nm) is ~ 7 times larger than the β-strand distance (0.47 nm), this points to a potential steric clash. Hence, we investigated the influence of the GFP tag on Tau(FL) or Tau(RD) aggregation. Using biophysical methods (light scattering, atomic force microscopy (AFM), and scanning-transmission electron microscopy (STEM)), we found that the assembly of Tau(RD)-GFP was severely inhibited and incompatible with that of Alzheimer filaments. These observations argue against the hypothesis that the propagation of Tau pathology in AD is caused by the prion-like templated aggregation of Tau protein, transmitted via cell-to-cell spreading of Tau. Thus, even though the observed local increase of FRET in recipient cells may be a valid hallmark of a pathological reaction, our data argue that it is caused by a process distinct from assembly of Tau(RD) filaments. |
format | Online Article Text |
id | pubmed-7364478 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-73644782020-07-20 FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments Kaniyappan, Senthilvelrajan Tepper, Katharina Biernat, Jacek Chandupatla, Ram Reddy Hübschmann, Sabrina Irsen, Stephan Bicher, Sandra Klatt, Christoph Mandelkow, Eva-Maria Mandelkow, Eckhard Mol Neurodegener Research Article Tau aggregation into amyloid fibers based on the cross-beta structure is a hallmark of several Tauopathies, including Alzheimer Disease (AD). Trans-cellular propagation of Tau with pathological conformation has been suggested as a key disease mechanism. This is thought to cause the spreading of Tau pathology in AD by templated conversion of naive Tau in recipient cells into a pathological state, followed by assembly of pathological Tau fibers, similar to the mechanism of nucleated polymerization proposed for prion pathogenesis. In cell cultures, the process is often monitored by a FRET assay where the recipient cell expresses the Tau repeat domain (Tau(RD)) with a pro-aggregant mutation, fused to GFP-based FRET pairs. Since the size of the reporter GFP (barrel of ~ 3 nm × 4 nm) is ~ 7 times larger than the β-strand distance (0.47 nm), this points to a potential steric clash. Hence, we investigated the influence of the GFP tag on Tau(FL) or Tau(RD) aggregation. Using biophysical methods (light scattering, atomic force microscopy (AFM), and scanning-transmission electron microscopy (STEM)), we found that the assembly of Tau(RD)-GFP was severely inhibited and incompatible with that of Alzheimer filaments. These observations argue against the hypothesis that the propagation of Tau pathology in AD is caused by the prion-like templated aggregation of Tau protein, transmitted via cell-to-cell spreading of Tau. Thus, even though the observed local increase of FRET in recipient cells may be a valid hallmark of a pathological reaction, our data argue that it is caused by a process distinct from assembly of Tau(RD) filaments. BioMed Central 2020-07-16 /pmc/articles/PMC7364478/ /pubmed/32677995 http://dx.doi.org/10.1186/s13024-020-00389-1 Text en © The Author(s) 2020 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. |
spellingShingle | Research Article Kaniyappan, Senthilvelrajan Tepper, Katharina Biernat, Jacek Chandupatla, Ram Reddy Hübschmann, Sabrina Irsen, Stephan Bicher, Sandra Klatt, Christoph Mandelkow, Eva-Maria Mandelkow, Eckhard FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title | FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title_full | FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title_fullStr | FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title_full_unstemmed | FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title_short | FRET-based Tau seeding assay does not represent prion-like templated assembly of Tau filaments |
title_sort | fret-based tau seeding assay does not represent prion-like templated assembly of tau filaments |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7364478/ https://www.ncbi.nlm.nih.gov/pubmed/32677995 http://dx.doi.org/10.1186/s13024-020-00389-1 |
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