EMP2-induced cell death has features of apoptosis.

EMP2 or vector control infectant NIH3T3 cells were cultured for 20 or 40 hours in 0.5% serum and assayed for cell death. (A) Propidium iodide and annexin V staining. Time 0 represents cells before transfer to 0.5% serum conditions. EMP2 infectants after 20 hours express a more than 8-fold increase in annexin V staining compared with vector control infectants. (B) Cells were cultured in 0.5% serum supplemented with either 0.5% DMSO (▪), Z-VAD (30 μM in 0.5% DMSO) (▨), or Z-DEVD (30 μM in 0.5% DMSO) (░). Two days later, cells were harvested, and viable cells were enumerated using trypan blue exclusion. Inhibitors reversed EMP2-mediated serum deprivation apoptosis.