Seed-competent tau monomer initiates pathology in a tauopathy mouse model

Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved..

Tau aggregation into ordered assemblies causes neurodegenerative tauopathies. We previously reported that tau monomer exists in either inert (Mi) or seed-competent (Ms) conformational ensembles and that Ms encodes strains, that is, unique, self-replicating, biologically active assemblies. It is unknown if disease begins with Ms formation followed by fibril assembly or if Ms derives from fibrils and is therefore an epiphenomenon. Here, we studied a tauopathy mouse model (PS19) that expresses full-length mutant human (1N4R) tau (P301S). Insoluble tau seeding activity appeared at 2 months of age and insoluble tau protein assemblies by immunoblot at 3 months. Tau monomer from mice aged 1 to 6 weeks, purified using size-exclusion chromatography, contained soluble seeding activity at 4 weeks, before insoluble material or larger assemblies were observed, with assemblies ranging from n = 1 to 3 tau units. By 5 to 6 weeks, large soluble assemblies had formed. This indicated that the first detectable pathological forms of tau were in fact Ms. We next examined posttranslational modifications of tau monomer from 1 to 6 weeks. We detected no phosphorylation unique to Ms in PS19 or human Alzheimer's disease brains. We conclude that tauopathy begins with formation of the Ms monomer, whose activity is phosphorylation independent. Ms then self assembles to form oligomers before it forms insoluble fibrils. The conversion of tau monomer from Mi to Ms thus constitutes the first detectable step in the initiation of tauopathy in this mouse model, with obvious implications for the origins of tauopathy in humans.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:298

Enthalten in:

The Journal of biological chemistry - 298(2022), 8 vom: 15. Aug., Seite 102163

Sprache:

Englisch

Beteiligte Personen:

Mirbaha, Hilda [VerfasserIn]
Chen, Dailu [VerfasserIn]
Mullapudi, Vishruth [VerfasserIn]
Terpack, Sandi Jo [VerfasserIn]
White, Charles L [VerfasserIn]
Joachimiak, Lukasz A [VerfasserIn]
Diamond, Marc I [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Pathology
Prion
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Seed-competent monomer
Size-exclusion chromatography
Tau Proteins
Tauopathy
Tauopathy mouse model

Anmerkungen:

Date Completed 08.09.2022

Date Revised 17.10.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jbc.2022.102163

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM342712632