Figure 3.

Northern hybridization analyses of S. cerevisiae strains expressing ARO7^c and TRP2 with altered dependence on the general control activator Gcn4p. Cells were cultivated in minimal medium and expressed no functional Gcn4p (−) or low levels (+) or high levels (+++) of Gcn4p, as indicated. In each lane, 25 μg of total RNAs was hybridized successively with probes specific for ARO7/TRP2 and ACT1 (encoding actin). For quantification, steady-state transcript levels were standardized with respect to ACT1 levels and the ratio between ARO7^c and TRP2 transcript levels is indicated at the bottom. All values are the means of two independent measurements with a standard deviation not exceeding 20%.