FIG. 3.

Residues 114 to 131 are required for nuclear export of VHL. (A) Map of the nuclear export domain of VHL. The schematic diagram indicates deletion mutants of VHL that were submitted to cytoplasmic FLIP to assess the nuclear export activity. + and - indicate the ability or inability of the fusion protein to engage in nuclear export. (B) MCF-7 cells transiently transfected with PK-GFP-NLS, ΔC157-PK-GFP-NLS, or Δ114-131-PK-GFP-NLS were submitted to cytoplasmic FLIP, in which a small cytoplasmic region of a cell was bleached repetitively. The loss of nuclear GFP fluorescence was monitored over time and plotted on a graph. (C) Cells transiently expressing Δ114-131-GFP were initially bleached in a large cytoplasmic region followed by repetitive bleaching in a small cytoplasmic region after being treated for 1 h with 2 μM ActD or left untreated. Kinetics for the loss of nuclear fluorescence were calculated and plotted on a graph.