Figure 1.

Characterization of ERK2 import in permeabilized REF52 and BRL cells. (A) Nuclear import of His-6-ERK2 (0.8 μM, 50 μg/ml) in REF52 cells with or without an energy regenerating system (see Experimental Procedures) in the absence of transport factors was visualized by immunofluorescence. (B) Coomassie-stained polyacrylamide gel of purified GFP-ERK2. (C) Nuclear import of GFP-ERK2 (0.8 μM 50 μg/ml) and TRITC-NLS-BSA (1.4 μM) in BRL cells in the presence of an energy regenerating system plus the indicated factors. (Magnifications: ×63.)