Fig. 9: Proteins harbouring localised sequence promiscuity to the VQIVYK aggregation prone peptide modify susceptibility to tau spreading in FRET biosensor cells.
a Graphical depiction of the experimental setup in the tau biosensor cells. Transient expression of protein constructs, followed-up by secondary tau seeds transfection is measured by quantifying the formation of individual FRET-intensive puncta in construct-expressing (traced with HA staining) and non-expressing cells. Created with BioRender. b FRAP measurements of FRET-intensive puncta in the biosensor cells. Complete absence of fluorescence recovery was observed after every successive bleaching step of fluorescence puncta. c Representative images of cells expressing individual constructs (HA staining channel) containing tau inclusions shown as fluorescent puncta (FRET channel). Merging of the two channels indicates significant colocalization (purple regions) between HA-intense and FRET-intense regions in expressing cells (Bar = 100 μm). d Quantification of HA-intense and FRET colocalisation in expressing cells. Pearson’s correlation coefficient values for individual cells are represented, with error bars indicating mean values ± SD (n = 10 from three independent wells). e, f Absolute quantification of d the number of construct-expressing and non-expressing cells containing tau aggregates (n = 3 independent experiments) or e the number of spots per cell after dose-dependent treatment with tau seeds, compared side-by-side to the vehicle control (no construct transfection), as well as to tauRD and 2N4R transfected cells, respectively. Bar plots highlight differentials observed in cells when treated with the highest concentration of tau seeds (500 nM). Data are represented as mean values ± SD. Statistical significance was calculated using one-way ANOVA with multiple comparisons. Source data are provided as a Source Data file.
