Figure 1.

CBP, p300 and MOF possess histone crotonyltransferase (HCT) activities. (a) Examining the HCT activity for ectopically expressed CBP, p300 and MOF by immunofluorescent (IF) staining assay using pan-Kcr antibody. HeLa cells were transfected with expression plasmids for CBP, p300 or MOF and the histone acetyltransferase (HAT) and HCT activities were detected by IF staining using pan-Kcr or pan-Kac antibody as indicated. Scale bar, 20 μm. (b) IF staining assay showing that the CBP, p300 and MOF mutants inactive for HAT activity were also inactive in catalyzing crotonylation. Scale bar, 20 μm. (c–e) Western blotting (WB) analysis of core histones derived from HeLa cells transfected with or without the wild-type or mutant CBP (c), the wild-type or mutant p300 (d) or the wild-type or mutant MOF (e).