Fig. 1: PD-linked mutant DNAJC13 perturbs the retrograde cargo trafficking from early endosomes to the TGN.

A The COS7 cells overexpressing GFP, GFP-DNAJC13^wt, or GFP-DNAJC13^N855S (green) were immunostained with the early endosomal marker EEA1 (magenta) and images were observed using confocal laser microscopy. Both GFP-DNAJC13^wt and GFP-DNAJC13^N855S colocalized with the EEA1-positive early endosomes. In cells expressing GFP alone showed artificial localization in the nucleus. Cell contours are indicated by the white dotted lines. Scale bar: 20 μm. B The average size of the EEA1-positive endosomes in the cells expressing GFP-DNAJC13^N855S was significantly larger than that of GFP or GFP-DNAJC13^wt. Data were statistically analyzed by Kruskal–Wallis and post hoc Bonferroni tests. *p < 0.05, n = 33 (GFP), 32 (GFP-DNAJC13^wt), and 36 (GFP-DNAJC13^N855S). C The COS7 cells overexpressing GFP, GFP-DNAJC13^wt, or GFP-DNAJC13^N855S (green) were double-immunostained with TGN46 (magenta) and M6PR (cyan) and images were captured using confocal laser microscopy. Cell contours are indicated by the white dotted lines. Scale bar: 20 μm. D The colocalization ratio of TGN46 and M6PR was significantly lower in the cells expressing GFP-DNAJC13^N855S than in those expressing GFP alone or GFP-DNAJC13^wt. Data were statistically analyzed by Kruskal–Wallis and post hoc Bonferroni tests. *p < 0.05, n = 23 (GFP), 26 (GFP-DNAJC13^wt), and 29 (GFP-DNAJC13^N855S). E Co-IP analysis of the DNAJC13-M6PR interaction using COS7 cells. Both GFP-DNAJC13^wt and GFP-DNAJC13^N855S, but not GFP alone, bind M6PR to the same extent.