FIG. 3.

Inducible expression of Gadd153 sensitizes cells to ER stress-induced death. (A) gadd153, under control of an IPTG-inducible promoter, was introduced into Rat1 fibroblasts and MEFs derived from gadd153/chop^−/− mice. Accumulation of Gadd153 is evident in Western blots following introduction of 5 mM IPTG to the culture medium. (B and C) Rat1-Gadd153i (B) and gadd153^−/− Gadd153i (C) cells were treated with thapsigargin (1 μM, 24 h) or tunicamycin (1 μg/ml, 24 h) in the presence or absence of 5 mM IPTG, and apoptosis was quantified using flow cytometry. Data are averages of at least three independent experiments. Error bars represent standard errors of the means.