A transient histone hyperacetylation signal marks nucleosomes for remodeling at the PHO8 promoter in vivo

Chromatin remodeling of the yeast PHO8 promoter requires the SAGA histone acetyltransferase complex. We report here that SAGA is necessary and sufficient to establish an activator-dependent hyperacetylation peak over the PHO8 promoter that is restricted to those nucleosomes that are remodeled upon activation. This local hyperacetylated state is observed upon activation in the absence of the SWI/SNF complex when the remodeling process is frozen subsequent to activator binding. Hyperacetylation is lost, however, if remodeling is permitted to go to completion. Thus, a transient histone hyperacetylation signal is shown to be a prerequisite for, and determinant of, the domain of nucleosome remodeling in vivo.