Figure 6.

Overexpression of EIG121 increases acidic vesicles and the degradation of long-lived proteins. T-Rex-293-EIG121 clone A cells (a) or T-Rex-293-LacZ cells (b) were grown in six-well plates and incubated without or with tetracycline for 24 or 48 h. Cells were then incubated in medium containing acridine orange and collected by trypsinization for flow cytometry analysis. Plotted are fold increase of cells containing acidic vesicular organelles. (c) T-Rex-293-EIG121 clone A cells were grown in 12-well plates and incubated in the presence or absence of tracycline for either 8 or 24 h. Cells were then labeled in medium containing ¹⁴C-valine and chased first for 3 h to deplete short-lived proteins and then for another 16 h. The degradation of long-lived proteins was represented by the radioactivity released into the medium during the last 16 h (the ratio of TCA-soluble radioactivity to the total cellular radioactivity). Each group contained five replicates, and data shown (mean±S.E.M.) are representative of three independent experiments