Figure 3.

Effect of MAP kinases on nuclear uptake of GFP-ERK2. Import assay (A) and quantitation (B) using GFP-ERK2 (0.8 μM, 50 μg/ml) was performed in REF52 cells in the presence of increasing amounts of ERK2 (filled bars) and ERK2-P2 (open bars). Hatched bar is accumulation without excess ERK2. (C and D) Quantitation of nuclear fluorescence from import assay using GFP-ERK2 (0.8 μM, 50 μg/ml) in REF52 cells in the presence of increasing amounts of JNK2 (C) and p38α (D). Hatched bar is accumulation without excess MAP kinases. (Magnification: A, ×63.)