Figure 3. The tail and head/middle modules behave as separate complexes in sin4Δ cells.

(A,B) Recruitment of Gal11p and Srb4p to the FLR1 promoter and coding region in wild-type cells. (C,D) Recruitment of Gal11p and Srb4p to the FLR1 promoter and coding region in sin4Δ cells. (E) Recruitment of Gal11p to the FLR1 promoter in wild-type, sin4Δ, swi2Δ, yap1Δ, sin4Δ swi2Δ, and sin4Δ yap1Δ cells. Gal11p and Srb4p occupancies were determined in strains expressing Gal11p-3HA and Srb4p-myc9 using anti-HA and anti-myc antibodies, respectively. ChIP was performed using chromatin from the corresponding cells grown in YPD medium (0 h) and treated with benomyl (5 µg/ml) for 1 h. Each immunoprecipitation was performed at least three times using different chromatin samples. The occupancy was calculated with POL1 coding sequence as a negative control. The data are presented as fold occupancy over the POL1 coding sequence control and represent means ± SD. (F) FLR1 expression in sin4Δ cells requires MED2. Indicated trains were grown in YPD medium at 30°C to an A₆₀₀ of 1.0. Benomyl was added to a final concentration of 5 µg/ml and samples were collected after 0, 1, and 3 h. Total RNA was isolated and assayed for ACT1 and FLR1 transcripts by real-time RT-PCR. The results were normalized to ACT1 RNA and expressed relative to the value for the WT strain at 0 h. The experiment was repeated three times, and the results are shown as means ± SD.