FIG. 8.

Tupl-mediated repression is associated with local deacetylation of histone tails. Cross-linked chromatin preparations from strain FT5 and the isogenic tup1 deletion strain were immunoprecipitated with antibodies against the acetylated tails of H3 and H4. (A) The promoter region of the indicated genes was PCR amplified from immunoprecipitated and input DNAs. WT, wild type; Δ, mutant. (B) PCR was performed with primer pairs spanning the MFA1 locus and centered approximately at the distance indicated from the α2-Mcm1 binding sites that serve to recruit the Cyc8-Tup1 corepressor. A map of the MFAl locus indicates the position of the α2-Mcml operator (black box), the pheromone response elements bound by Ste 12 (white boxes), and the TATA element (grey box). The relative H3 and H4 deacetylation associated with Tupl was calculated as detailed in Materials and Methods.