Fig. 2

Time-course study of cell-surface β PP trafficking after PDBu

Radioiodinated 1G7 IgG was used to determine the rate of βPP release and internalization from the cell surface in wild-type CHO cell line. The radioactivity from media (A), acid resistant lysates (B), and acid labile wash (C) was taken to represent secreted, internalized, and cell surface βPP, respectively. Within each of the three fractions, the result obtained at each time point is expressed as a percent of radioactivity of cell lysates obtained at time 0. The value from the three fractions is <100% because only TCA-precipitable radioactivity was taken into account and because of the variation in radioactivity obtained at each time point. The data are the averages ± SEM of three independent experiments. The differences in the media and internalized fractions between control and PDBu treated cells were statistically significant at each of the four time points (p < .05 to p < .003).