FIG. 8.

Vps75 regulates transcription-dependent accumulation of histone H3 acetylated at lysine 56 (H3K56ac) at GAL10. (A) Loss of histone H3 at GAL10 following induction. Wild-type (WT) or vps75Δ cells were grown in raffinose and arrested in G₁ phase with α-factor. Cells were then treated with formaldehyde before (raffinose) or after (galactose) a 1-h induction with galactose. The relative levels of histone H3 at the induced GAL10 gene were then determined by ChIP assays followed by quantitative PCR. Values shown are the averages, with standard errors, of four independent experiments and are expressed as the amounts of immunoprecipitated DNA corrected to input DNA. Values in galactose were set to 1 and other values expressed relative to that. Prom, promoter; Mid, middle of ORF. (B) Defects in H3K56ac accumulation at induced GAL10 in cells lacking Vps75. Wild-type or vps75Δ cells were grown and treated with formaldehyde as described for panel A. The relative levels of H3K56ac at the induced GAL10 gene in were then determined by ChIP assays followed by quantitative PCR. Values shown are the averages, with standard errors, of four independent experiments and are expressed as the amounts of immunoprecipitated DNA corrected to that of input DNA and normalized to total histone H3 levels. The value for the wild-type strain in galactose was set to 1 and other values expressed relative to that. Prom, promoter; Mid, middle of ORF. A one-sample t test was used to determine statistical significance, with an asterisk denoting a P value of <0.05. The key is as shown in panel A. (C) Normal H3K56ac at genes exhibiting altered H2B exchange. H3K56ac levels in wild-type and vps75Δ cells were measured as described for panel B. The value for the wild-type strain in galactose was set to 1 and other values expressed relative to that. Prom, promoter; Mid, middle of ORF; TEL, telomeric DNA on chromosome 6. The key is as shown for panel A.