FIG. 4.

The interaction of the Tat NLS with Imp β is inhibited by Ran GTP. (A) Micro-affinity chromatography, using columns bearing the wild-type GST-TatNLS or mutant GST-TatM1 fusion proteins, was performed as described in the legend to Fig. 3. (B) Glutathione-Sepharose beads bearing the wild-type GST-TatNLS protein were loaded with recombinant Imp β and then incubated in buffer alone or with added RanGTP or RanGDP. After washing, the residual bound Imp β was released with SDS and analyzed by SDS-PAGE.