Structural polymorphism of α-synuclein fibrils alters the pathway of Hsc70-mediated disaggregation

Pathological aggregation of α-synuclein into amyloid fibrils is a hallmark of synucleinopathies, including Parkinson’s disease. Despite this commonality, synucleinopathies display divergent disease phenotypes that have been attributed to disease-specific three-dimensional structures of α-synuclein f...

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Main Authors: Jäger, Svenja (Author) , Tittelmeier, Jessica (Author) , Dang, Thi-Lieu (Author) , Bellande, Tracy (Author) , Redeker, Virginie (Author) , Buell, Alexander K. (Author) , Hennig, Janosch (Author) , Melki, Ronald (Author) , Nussbaum-Krammer, Carmen (Author) , Bukau, Bernd (Author) , Wentink, Anne (Author)
Format: Article (Journal)
Language:English
Published: 6 October 2025
In: The EMBO journal
Year: 2025, Volume: 44, Issue: 22, Pages: 6499-6526
ISSN:1460-2075
DOI:10.1038/s44318-025-00573-3
Online Access:Verlag, kostenfrei, Volltext: https://doi.org/10.1038/s44318-025-00573-3
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Author Notes:Svenja Jäger, Jessica Tittelmeier, Thi Lieu Dang, Tracy Bellande, Virginie Redeker, Alexander K. Buell, Janosch Hennig, Ronald Melki, Carmen Nussbaum-Krammer, Bernd Bukau & Anne S. Wentink
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Summary:Pathological aggregation of α-synuclein into amyloid fibrils is a hallmark of synucleinopathies, including Parkinson’s disease. Despite this commonality, synucleinopathies display divergent disease phenotypes that have been attributed to disease-specific three-dimensional structures of α-synuclein fibrils, each with unique toxic gain-of-function profiles. The Hsc70 chaperone is remarkable in its ability to disassemble pre-existing amyloid fibrils of different proteins in an ATP and co-chaperone-dependent manner. We find, however, using six well-defined conformational polymorphs of α-synuclein fibrils, that the activity of the Hsc70 disaggregase machinery is sensitive to differences in the amyloid conformation, confirming that fibril polymorphism directly affects interactions with the proteostasis network. Amyloid conformation influences not only how efficiently fibrils are cleared by the Hsc70 machinery but also the balance between depolymerization and fragmentation during disaggregation. We further show that, in vitro, the active processing of fibrils by the Hsc70 machinery inadvertently produces seeding competent species that further promote protein aggregation. Amyloid conformation thus is an important feature that can tilt the balance between beneficial or detrimental protein quality control activities in a disease-context.
Item Description:Gesehen am 13.02.2026
Physical Description:Online Resource
ISSN:1460-2075
DOI:10.1038/s44318-025-00573-3