Fig. 2.
Effect of SubAB on eIF2α phosphorylation and protein synthesis. Vero cell monolayers were incubated with the indicated dose of SubAB, or 1 μg ml−1 SubAA272B for 0.5, 1, 2 or 4 h. Levels of eIF2α-P and total eIF2α were then determined by Western blotting, as for Fig. 1. Figures below each lane are fold induction of eIF2α-P following SubAB treatment, relative to treatment with SubAA272B (normalized to loading controls), determined by densitometry using ImageJ 1.38× software. Effects on global protein synthesis were also measured by assessment of [3H]-leucine incorporation into TCA-precipitable material during a 60 min pulse, as described in Experimental procedures. Data are the mean ± SEM from three independent experiments, expressed as a percentage of the untreated control for each time point. NS, not significant; *, P < 0.0001; **, P < 0.002 (two-tailed t-test).