FIG. 4.

esa1 mutants display conditional decreases in the level of histone H4-Lys5 acetylation in vivo. Whole-cell lysates from wild-type (WT; lanes 2, 6, and 10) or esa1 temperature-sensitive (lanes 3 to 5, 7 to 9, and 11 to 13) strains grown at 28°C (lanes 2 to 5) or 37°C (lanes 6 to 13) were separated on an SDS–18% polyacrylamide gel and either transferred to nylon and probed with an antiserum directed against Ly5-acetylated H4 (A) or probed with a control antiserum directed against histones (B; upper panel shows H4 immunoreactive band) or stained with Coomassie brilliant Blue (B, lower panel). Purified yeast histones (YH; approximately 6 μg; lane 1) were run in parallel. esa1-L254P (LPY3500; lanes 3, 7, and 11), esa1-414 (LPY3291; lanes 4, 8, and 12), and esa1-L327S (LPY3430; lanes 5, 9, and 13) strain displayed decreased Lys5-acetylated immunoreactivity at the nonpermissive temperature of 37°C. Arrowheads denote migration of histone H4.