Figure 8.

(A) Msn5 is required for export of Rtg1 and Rtg3 from the nucleus. (A) msn5Δ (EY0736) and msn5Δ rtg2Δ (EY0744) cells were transformed with pRtg1-GFP (top) or pRtg3-GFP (bottom) and grown to 0.5 OD₆₀₀/ml in SCD media lacking uracil and were examined by fluorescence microscopy. Rtg1-GFP and Rtg3-GFP were localized constitutively within the nucleus in msn5Δ cells but not in msn5Δ rtg2Δ cells. (B) RTG-dependent target genes remain responsive to TOR signaling in msn5Δ cells. Wild-type (K699) and msn5Δ (EY0736) cells were grown in YPD until 0.5 OD₆₀₀/ml and were treated either with drug vehicle (lanes 1 and 3) or with rapamycin (lanes 2 and 4) for 30 min (this time of incubation corresponded to the peak induction of RTG-dependent gene expression observed in the rapamycin time course in Fig. 6). Cells were then harvested and RNA was prepared and analyzed by Northern blotting, probing for the specified mRNAs.