Updated project metadata. 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).