Figure 2.

Loss of the PP2A holoenzyme destabilizes individual PP2A subunits. Drosophila S2 cells were incubated in the presence of EGFP, A- or C-subunit dsRNA for 48 h (Right). The cells were then treated with 500 μM cycloheximide for the times indicated and lysed in RIPA buffer containing 0.2 mM Na₂VO₄ and 10 mM NaF₂. Lysates were clarified by centrifugation, and equal amounts of proteins (50 μg) were resolved by SDS-polyacrylamide gel electrophoresis and detected by Western blotting with antibodies against the A, C, R2/B, or R5/B56–1 subunits as indicated at the right of each row. Results shown are representative of three experiments.