Fig. 8.

Specific cytosolic cargo accumulates in the core of GVBs. Tau pathology was induced in primary mouse neurons expressing tau P301L by treatment with PFFs. a, b Representative confocal images and fluorescence intensity profiles of immunostaining using the GVB core marker CK1δ (red) with AT100 staining (a) or with direct fluorescence signal from tau-P301L-GFP (b) (green). c Representative super-resolution image obtained by STED microscopy showing tau-P301L-GFP (green), CK1δ (red) and the GVB membrane marker LIMP2 (cyan). One of the GVBs in this image is also shown in Fig. 7a. d Representative confocal image and fluorescence intensity profile of immunostaining using CK1δ (red) plus Myc staining (green) to visualize the PFFs. e Representative confocal images showing tau-P301L-mCherry co-expressed with either GFP or CK1δ-GFP. Neurons were immunostained using the GVB marker CK1ɛ and the neuron-specific dendrite marker MAP2. Individual fluorescence signals are shown separately in grayscale and in color in the merge: GFP and CK1δ-GFP in green and CK1ɛ in red. MAP2 is shown in gray in the merge. Tau-P301L-mCherry signal is not shown in the merge. f Quantification of e showing the GVB/cytosol fluorescence intensity ratio of GFP and CK1δ-GFP fluorescence. N = 3 independent experiments, N = 34 and 47 neurons analyzed for GFP and CK1δ-GFP, respectively. ***p < 0.001, Mann–Whitney U test. g Representative confocal image and fluorescence intensity profile of the expression of CK1δ-GFP (green) plus immunostaining for LIMP2 (red) and MAP2 (gray). MAP2 is not shown in the zooms. See Supplementary Table 3 in Online Resource 1 for an overview of the number of cells analyzed