FIG. 6.
Movement of MCP from the cytoplasmic to the nuclear fraction slowed in cells infected with NLS mutants. HFF cells infected with WT, NLS1−, or NLS2− virus were pulse radiolabeled for 1 h with [35S]Met/Cys, collected, separated into NP-40 cytoplasmic (Cyto) and nuclear (Nuc) fractions, subjected to immunoprecipitation using anti-MCP, and analyzed by phosphorimaging following SDS-PAGE, all as described in Results and Materials and Methods. (A) Phosphorimages of the resulting cytoplasmic and nuclear fractions prepared immediately after the 1-h radiolabeling period (0) and after additional chase periods of 4, 8, 24, and 48 h. Positions of MCP and the immunologically cross-reactive 120-kDa fragment (frag.) are indicated. (B) The percentage of MCP plus fragment in the cytoplasmic (filled symbols) and nuclear (empty symbols) fractions at each time point. (C) The relative amount of fragment per amount of MCP in the cytoplasmic (filled symbols) and nuclear (empty symbols) fractions at each time point.