Figure 7.

VSVG folding in statin-treated cells is largely normal. (A) CHO cells grown in LPDS were transfected with YFP-VSVG and incubated at 39.5°C overnight. Cells were then incubated at 39.5°C for an additional hour with or without 40 μM lovastatin. Some of the cells were fixed immediately (a–d), whereas other cells were transferred to 32°C incubator for 15 min (e–h) before fixation. Cells were then immunostained with I14, a mAb that only recognizes correctly folded VSVG. I14 was recognized by Alexa594 anti-mouse secondary antibody. (B) Fluorescent intensities of I14 immunostained cells were quantified. For each treatment, five images from random fields of cells were taken with a 10× objective for YFP (514 nm) and I14 (594 nm). After background subtraction, corresponding images were divided (594/514), and fluorescent intensities were calculated for each image. The bars represent the average of five random fields, and error bars are the SDs. I14 staining was also measured in cells that incubated at 32°C for 5, 10, and 15 min (inset). (C) CHO cells expressing YFP-ER were treated with or without 40 μM lovastatin for 1 h before FRAP experiments. The fluorescence intensities from photobleached spots were plotted as percentage of prebleach intensity in the same area against time. Each curve represents the average from five to 10 cells. Error bars are SEM.