Identification of the Tau aggresome in progressive supranuclear palsy by in situ biotinylation by antibody recognition reveals protein networks involved in energy metabolism, cytoskeletal dynamics and protein degradation systems.

ABSTRACT: Progressive supranuclear palsy (PSP) is a late-onset neurodegenerative disease defined pathologically by the presence of insoluble phosphorylated-Tau (p-Tau) in neurons and glia. Identifying co-aggregating proteins within p-Tau inclusions reveals important insights into processes affected by the aggregation of Tau. Here, we used an unbiased proteomic approach, which combines antibody-mediated proximity-detection of co-aggregated proteins together with mass spectrometry. Biotinylation by antibody recognition (BAR) is a recently developed method, by which a primary antibody recognises the target of interest in fixed samples. A secondary antibody conjugated to horseradish peroxidase (HRP) recognises the primary antibody, and with the addition of biotin phenol and hydrogen peroxide, facilitates biotinylation of proteins in close proximity. Biotinylated proteins are then biochemically isolated and identified using mass spectrometry (MS). Using this workflow, we characterised the aggresome of p-Tau in PSP cases, identifying >80% of previously identified interaction partners of Tau as well as known modifiers of Tau aggregation. Our data also identified confidently assigned phosphorylation sites that have previously been reported on p-Tau. Together these data validate our proof-of-concept approach to rapidly identify proteins in proximity to p-Tau from post-mortem tissue whilst also isolating novel protein components that have not been previously associated with p-Tau.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Brain

SUBMITTER: Albert Lee  

LAB HEAD: Albert Lee

PROVIDER: PXD028770 | Pride | 2023-02-27

REPOSITORIES: Pride