X-Box Binding Protein 1 (XBP1s) Is a Critical Determinant of Pseudomonas aeruginosa Homoserine Lactone-Mediated Apoptosis
Figure 6
XBP1-independent cellular responses to C12.
A. Immunoblot analysis of phosphorylated eIF2α (p-eIF2α, left) and phosphorylated p38 (p-p38, right) levels in wt, Ire1α−/− and Xbp1−/− MEFs. Cells were treated with 25 µM C12 for 45 minutes. B. (top) C12 treatment (25 µM, 45 min) of Perk−/− MEFs results in phosphorylation of eIF2α (bottom) Control experiments confirm that ER stress (brefeldin A (BFA), 2 hours) in wt MEFs, but not Perk−/− MEFs, produces p-eIF2α. C. C12 treatment increases c-Jun levels in wt MEFs but not in Ire1α−/−, and Xbp1−/− MEFs. Cells were treated with 25 µM C12 for 90 minutes (bottom) and c-Jun levels were characterized by image analysis of immunostained cells (green). Images of DAPI staining are also shown (magenta). D. Quantitative analysis of normalized c-Jun levels in wt, Ire1α−/−, and Xbp1−/− MEFs. Scale bar in panel C refers to all images.