Figure 1.

Strategy for the preparation of a double-stranded DNA fragment coupled to an NLS peptide. A functional luciferase gene of 3,380 bp was cut out of pCMVLuc with XmaI and SalI. Further digestion with XmnI and BspHI cut the unwanted restriction fragment into small fragments (970, 875, 768, and 240 bp) that were removed by sucrose gradient centrifugation. The capped CMVLuc-NLS DNA was obtained by ligation of the ³²P-labeled (∗) oligonucleotide-peptide and oligonucleotide-cap hairpins to the restriction fragment.