Figure 4

Squalestatin reroutes MoPrP105-132 into lysosomes. Neuroblastoma cells were incubated with 1 μM squalestatin for 24 hours before incubation with 30 μM MoPrP105-132-biotin for 90 minutes, then fixed and stained with Texas Red-streptavidin (red) and with anti-GM130, anti-Grp78, anti-TfR-FITC or anti-LAMP-1-FITC (all green) (A) Co-localisation between MoPrP105-132 and GM130, or (B) between MoPrP105-132 and Grp78. (C) In squalestatin treated cells co-localisation was observed between MoPrP105-132 and TfR and (D) between MoPrP105-132 and LAMP-1. Scale bars, 5 μm. (E) In squalestatin-treated cells, following fractionation of whole microsomal extracts (MEx) using iron dextran and density gradient centrifugation, MoPrP105-132 was detected in the lysosome fraction (F3).