The proteasome inhibitor lactacystin increases susceptibility of the mutant insulin expressing clone to apoptosis. A. Clone #4S2 cells were untreated or treated with 2 μg/ml doxycycline for 48 h. Cells were then untreated or treated with 10 μM of lactacystin (LC) or an equivalent volume of DMSO for the times indicated. Apoptosis was measured using a cell death detection ELISA kit as described in the Methods. Shown are the mean ± SE of 3 independent experiments. *p < 0.05. B. Following 42 h of doxycycline treatment, cells were untreated, or treated with 10 μM of lactacystin (LC) or an equivalent volume of DMSO for 6 h in the presence of doxycycline. The cells were washed in PBS and lysed. Cell lysates (left panel) or TX-100 insoluble material (right panel) were resolved by SDS-PAGE and immunoblotted using the indicated antibodies. Note the increase in the levels of degradation products detected by the GFP antibody with LC treatment (arrowheads).
Hartley et al. BMC Cell Biology 2010 11:59 doi:10.1186/1471-2121-11-59