Figure 3.

Effect of proteasome inhibitor on PrP localization in COS cells. Cells expressing wild-type PrP were treated without (A) or with 5 μM epoxomicin for various lengths of time as indicated in B–D. (E) Cells without proteasome inhibition but overexpressing PrP because of high transfection levels. In all panels, PrP was stained with anti-PrP antibody (green). Giantin, hsc70, or γ-tubulin (red) staining with specific antibodies was indicated; nuclei were stained with DAPI (blue). All of the cells were fixed by methanol except for visualization of surface staining in cells fixed by paraformaldehyde. Large arrows in E, cells with cytoplasmic PrP colocalizing with Hsc70; small arrows in E, cells with PrP in the Golgi complex. (E, Right) Higher magnification of colocalization of PrP aggregates and hsc70.