FIGURE 10.

Differential interactions of UPS with tau and α-syn aggregates. A and B, ubiquitin and 20S staining for induced clone 4 cells at 2 days after tau PFF transduction. C and D, ubiquitin and 20S staining for clone 4.1 cells with transiently induced α-syn aggregates at 1 or 2 days after α-syn PFF transduction. Tau aggregates were visualized by GFP signals. α-Syn aggregates were labeled by antibodies specific for phosphorylated α-Syn (p-syn). Soluble proteins were extracted by 1% Triton X-100 during fixing. Scale bars, 50 μm. E and F, Manders coefficient for the fraction of area occupied by tau or α-Syn aggregates with colocalizing ubiquitin or 20S signals. Four conditions were quantified: 1) tau aggregates in clone 4 cells at 2 days after tau PFF transduction, 2) tau aggregates in clone 4.1 cells, 3) tau aggregates in clone 4.1 cells with transiently induced α-syn aggregates, and 4) transiently induced α-Syn aggregates in clone 4.1 cells. Quantification was based on 3 independent sets of experiments. Data are shown as mean ± S.E. The following pairwise comparisons were made using Student's t test: 1 versus 2, 2 versus 3, and 1 versus 4. *, p < 0.05. ***, p < 0.0005.