Fig. 4

Depletion of Pkh causes down-regulation of genes involved in ion transport. a Aft1 dependence of S. cerevisiae iron transport genes and their down-regulation by depletion of Pkh. Comparison of the transcriptional changes, in log₂, triggered by treatment of SDP8 cells with 100 μg/ml doxycycline for 24 h to CML476 when compared to wild-type cells under the same treatment (x axis) with data obtained when the expression pattern of aft1 mutant cells was compared to that of a wild-type isogenic strain carrying the constitutively activated AFT1-1 ^up allele [26]. b β-Galactosidase activity of cells containing the PHO84-LacZ reporter gene. SDP8 cells transformed with the plasmid PHO84-LacZ and liquid cultures of the resulting strain were treated with doxycycline (100 μg/ml) or the vehicle for 8 or 24 h, as specified in the Methods section. β-Galactosidase activity was measured in non-treated (empty bars) or treated (filled bars) cells. Data are mean ± SEM from three independent clones. Treated cells were compared with untreated cells at each time point using un-paired t-test (n = 3; one-tailed P value; *P < 0.05). c The 140 genes down-regulated by incubation of SDP8 cells with doxycycline for 24 h have been ordered according to their expression values when compared to the expression in wild-type cells under the same conditions. Genes coding for ribosomal proteins are denoted by empty squares