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Updated: Sep 2, 2026

In Vitro Aggregation Assays Using Hyperphosphorylated Tau Protein
Published on: January 2, 2015
Repositioning of polyubiquitin alters the pathologic tau filament structure
Ryohei Watanabe1, Benjamin C Creekmore1, Nabil F Darwich1
1Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Abstract:
Structurally diverse tau filaments form proteinaceous aggregates in a heterogeneous group of neurodegenerative diseases called tauopathies. The factors extrinsic to the highly ordered core structure that influence tau filament stability are not well understood. Here, we found that polyubiquitinated tau filaments from Alzheimer disease and vacuolar tauopathy human brain tissue exhibit distinct seeding patterns in mice, in association with differences in tau filament ultrastructure determined by cryo-electron microscopy. Chemical modulation of the polarity of polyubiquitin adjacent to the tau core with the small molecule ubistatin B resulted in the repositioning of poorly structured densities toward positively charged residues on the highly structured core filament, leading to shifting of the protofilament-protofilament interface of certain vacuolar tauopathy tau filaments. These results suggest that the structure of tau filaments that are associated with different seeding activities in vivo can be influenced by post-translational modifications.
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