Translation inhibitors were added as follows: rapamycin (Fisher), 16 h post-transfection (final concentration: 25 nM), hippuristanol (a generous gift from J. Pelletier, McGill University), 24 h before harvest (final concentration: 400 nM) and thapsigargin (Sigma), 4 h before harvest (final concentration: 300 nM). Transfected cells were harvested 48 h post-transfection. Non-adherent cells were centrifuged at 3000 g for 5 min, washed with PBS and lysed in 100 ml of Cell Passive Lysis Buffer (Promega). Adherent cells were washed with PBS and lysed in 400 ml of Cell Passive Lysis Buffer. Cell lysates were centrifuged 2 min at 13 000 g at 48C to remove cell debris, before luciferase assays.