Skip to main content
. 2003 Aug 5;100(17):9946–9951. doi: 10.1073/pnas.1334037100

Fig. 1.

Fig. 1.

PIs induce ER stress and caspase-12 activation, but suppress the UPR. (A) BiP and CHOP mRNA induction in NIH 3T3 or J558 myeloma cells treated with MG-132 (20 μM), Tm (10 μg/ml), or both. Cells were pretreated with MG-132 for 1 h and then further treated with Tm for 4 h. Ethidium bromide staining of the gel is shown at the bottom. (B) Alteration in the ratio of XBP-1 protein species in J558 cells treated with increasing amounts of MG-132 for 16 h. Cells undergoing apoptosis were counted by annexin V staining. (C) Inhibition of caspase-12 processing by PIs. Processing of full-length caspase-12 was examined by Western blotting in J558 myeloma cells treated with thap-sigargin (1 μM) or PIs (20 μM) during the indicated time periods. (D) Time course of the XBP-1s to -1u shift. Cells were treated with MG-132 (1 μM) for the indicated times, and XBP-1u and -1s protein levels and cell death were determined. (E) Alteration in the ratio of XBP-1 protein species in the MM.1s human myeloma cell line. Cells were treated with PS-341 (8 nM) in a time course analysis, and XBP-1 protein species were quantified.