Time course of changes in firefly luciferase (Luc) activities.

<p>A: Protocol for treating cells and measuring Luc activity. HeLa cells were transiently transfected with the pCMVluc+ and the pCMVβ to normalize differences in transfection efficiency. The cells were then treated with F-53 (B: 1 µM, D: 0.1–10 µM,) or PTC124 (C: 0.1 µM) for the incubation periods indicated in the figure (B–C). B and C: Luc activity was determined by measurement-1 in (A). D: Luc activity after the addition of F-53 in culture medium was determined by measurement-1 (black bar) and measurement-2 (white bar) in (A). Luc activity after the addition of F-53 at the same time as lysis was determined by measurement-3 (black bar) and measurement-4 (white bar) in (A). Luc activity after the addition of F-53 after lysis was determined by measurement-5 in (A). Treatment with F-53 after cell lysis involved treatment with a solution of F-53 in lysis buffer solution. Luc activity was normalized relative to β-gal activity. The results (Y-axes) are expressed as the fold increase in Luc activity after F-53 or PTC124 treatment, relative to the increase after treatment with DMSO. Each value represents the mean±SEM of three transfection experiments.