Figure 4.

The Golgi and ER exit sites remain intact in statin-treated cells. (A) CHO cells grown in LPDS or FCS were transfected with YFP-Golgi. Some cells were treated with 40 μM lovastatin for 1 h (b and d) before confocal microscopy. (B) CHO cells grown in LPDS were treated with 40 μM lovastatin or without (control) for 1 h. Cells were then fixed and immunostained for mannosidase II (first row), β-COP (second row), and COP II (third row). Antibodies were detected with Alexa 488 secondary antibodies against either mouse or rabbit. (C) CHO cells transiently expressing YFP-p58 were treated with 40 μM lovastatin for 1 h or without (control) before paraformaldehyde fixation. Cells were then imaged by confocal microscopy as z-series through out the cells volume. The z-projection images are shown (a and b). For single cell analysis in c, cells were imaged by wide-field fluorescence microscopy. The average fluorescence intensities from the Golgi and ER were taken and presented as Golgi/ER ratio to measure relative distribution. Each data point represents the average from more than 60 single cells and error bars are SEM.