Figure 6.

Cleavage of mEpCTF in human HEK293 cells. A, murine EpCTF-YFP was stably expressed in human HEK293 cells. Following pretreatment with DAPT (see “Experimental procedures”), cells were maintained in normal medium for a further 24 h. Cells were monitored at the indicated time points by immunofluorescence microscopy. Shown are representative pictures at the indicated time points from n = 3 independent experiments at ×200 and ×400 magnification. B, immunofluorescence microscopy results shown in A were quantified from n = 30 cells from n = 3 independent experiments. Shown are mean values ± S.E. (error bars). p values were calculated with one-way ANOVA. ****, p < 0.0001. C, visualization and quantification of mEpCTF-YFP and mEpICD-YFP expression, and calculation of mEpCTF 50% protein turnover was performed from n = 3 independent immunoblotting experiments. Shown are mean values with S.E. p values were calculated with one-way ANOVA. **, p < 0.01; ***, p < 0.001; ****, p < 0.0001. D, two-way ANOVA was used to calculate the difference at each time point between mEpCTF and hEpCTF in mF9 cells. The overall p value of the test is 0.10 with individual p values ranging from 0.34 to 0.99.