Figure 6
Mapping the nuclear export signal of mammalian COP1 protein (A) Diagram of the amino acid sequence of the wild-type COP1 NES, the alignment with the NESs of Rex and PKI. The amino acid replacements in the mutant protein (N200NESmut) are indicated by arrows. The conserved key residues are shown in boldface. Residues altered by site-directed mutagenesis are highlighted in red. (B) GFP fluorescence study of the subcellular localizations of GFP-N200 and GFP-N200NESmut. The studies were carried out in COS7 cells. When indicated, cells were cultured in the presence of 10 ng/ml LMB for 3 hrs before fixation. LMB, leptomycin B. The same magnification was used for all images and the scale bar for 10 micrometer was indicated in the N200+LMB image.