FIG. 4.

DON-induced GRP78 degradation in peritoneal macrophages is cathepsin/calpain dependent. (A) Peritoneal macrophages were incubated with ALLN, epoxomicin (EPO), or equivalent concentrations of DMSO (VH) for 1 h, and then incubated with DON (500 ng/ml) for 3 h. (B) Peritoneal macrophages were incubated with inhibitors to cathepsins (CATI-I) or calpains (CALI-III) or equivalent concentrations of DMSO (VH) for 1 h, and then incubated with DON (500 ng/ml) for 3 h. Total protein was extracted and GRP78 was analyzed by Western blot. RI indicates relative intensity which is the percentage of the maximal fluorescence in the same lane.