FIGURE 7.

Imp α/β binding to T-ag NLS-containing proteins is not influenced by the RbBS as determined by native gel electrophoresis/fluorography. A, increasing concentrations of predimerized IMP α/β were added to 0.5 μm of GFP-T-ag-(110–135) (top panel) or GFP-T-ag-(102–135) (bottom panel), incubated for 15 min at 30 °C, and then subjected to native gel electrophoresis and fluorography as described under “Experimental Procedures”. B, quantification of IMP α/β binding affinity. The Image J software was used to determine the percentage of protein with altered mobility for both GFP-T-ag-(110–135) (left panel) and GFP-T-ag-(102–135) (right panel). Apparent dissociation constants, determined by sigmoidal curve fitting, are indicated (see Table 2 for pooled data).