Figure 6.

GTT2 activation is Mediator dependent, but does not rely on the Med18, Med20 and Med20 subunits for expression. (A) GTT2 expression in strains with wild-type Med17 and a temperature sensitive mutant of Med17 (srb4-138). Transcript levels are shown at the permissive (30°C) and non-permissive temperature (37°C) in the uninduced condition, and 10 and 20 min after the addition of H₂O₂, as indicated. Transcript levels were analyzed as described in Figure 3. The average ±SD of three biological replicates is shown. (B) GTT2 activation is largely independent of the Med18, Med19 and Med20 proteins. RNA levels from indicated strains were analyzed as described in Figure 3. The average ±SD of three biological replicates is shown for all strains except the tail module deletions, which is shown in biological duplicate. (C) Mediator subunits are recruited to GTT2 during oxidative stress. Occupancy of Med14-HA, Med15-myc and Med18-myc were determined with a time course ChIP and analyzed as described in Figure 3. (D). Mediator and Yap1 occupancy at the GTT2 promoter is independent of Med20, as occupancy of Med15-myc and Yap1-myc increases on gene activation in both the wild-type (gray bars) and med20Δ strain (white bars). Occupancy of Med15-myc and Yap1-myc was determined with a time course ChIP and analyzed as described in Figure 3.