Fig. 7

Histone H3K4 methylation (H3K4me) and H3K56 acetylation (H3K56ac) levels in UV-exposed cells. Log-phase cultures were exposed to UV at 50 J/m², followed by a 4 h incubation. Samples were then collected, and isolated proteins were analyzed by western blot with histone modification-specific antibodies. Blots were subsequently analyzed by densitometry. Values were initially normalized relative to general H3 values to correct for histone level variation, and then subsequently normalized relative to the pre-exposure values for each modification (except panel D; normalized to unexposed wildtype cultures). Values are reported as means ± 1 SE reported for each condition. + UV, exposed cells; −UV, unexposed controls; PE, pre-exposure cells. A, B. H3K56 acetylation in wildtype cells. *p < 0.01. C, D. H3K56 acetylation in wildtype (WT), spt10, hst3/hst4, and rtt109 mutant strains. For data sets not sharing a letter on the graph, p < 0.01. E, F. Histone H3K4 methylation levels in wildtype cells. H3K4me1, monomethylation; H3K4me2, dimethylation; H3K4me3, trimethylation. *p < 0.01