FIG. 7.

Northern blot analysis revealing an increased degradation of ACT1 mRNA (right panels), which is retained in the nucleus because of the export deficiency caused by nup116-Δ or hpr1-Δ mutations at the restrictive temperature of 37°C when compared to the corresponding isogenic normal strain. The NUP116 (normal), nup116-Δ, and HPR1 and hpr1-Δ strains were grown at 25°C to the mid-logarithmic phase of growth. Subsequently, one-half of each culture was transferred to the restrictive temperature of 37°C; the cultures were further incubated for one additional hour at that temperature; and transcription was inhibited by the addition of thiolutin (4 μg/ml), as described in Materials and Methods. Northern blots were prepared using total RNA extracted from cells after various times, 0 to 50 min, of thiolutin addition. The half-lives, presented in Table 4, were determined from these blots after normalization to the 18S rRNA signals shown at the left panels. The numbers beside each panel represents the half-lives in minutes.