FIG. 6.

srp1-31 does not respond to rapamycin, implying that the yeast karyopherin α, Srp1p, is required for nuclear import of VDE. (A) The temperature-sensitive srp1-31 mutant cells show defects in nuclear transport of VDE. NOY388 (SRP1) or NOY612 (srp1-31) cells were cultured to log phase in YPD at 25°C, shifted to 37°C for 3 h, and either treated with 0.2 μg of rapamycin per ml for an hour or left untreated. The panels are presented as in Fig. 4A. Note that rapamycin-treated wild-type cells exhibit nuclear import of VDE (indicated by yellow in the nuclear zones), whereas, in contrast to other karyopherin mutations, rapamycin-treated srp1-31 cells do not. (B) The numbers of cells with nuclear fluorescence were counted, and the fractions were calculated as in Fig. 4B.