Global role for chromatin remodeling enzymes in mitotic gene expression

Regulation of eukaryotic gene expression requires ATP-dependent chromatin r emodeling enzymes, such as SWI/SNF, and histone acetyltransferases, such as Gcn5p. Here we show that SWI/SNF remodeling controls recruitment of Gcn5p HAT activity to many genes in late mitosis and that these chromatin remodel ing enzymes play a role in regulating mitotic exit. In contrast, interphase expression of GAL1, HIS3, PHO5, and PHO8 is accompanied by SWI/SNF-indepen dent recruitment of Gcn5p HAT activity. Surprisingly, prearresting cells in late mitosis imposes a requirement for SWI/SNF in recruiting Gcn5p HAT act ivity to the GAL1 promoter, and GAL1 expression also becomes dependent on b oth chromatin remodeling enzymes. We propose that SWI/SNF and Gcn5p are glo bally required for mitotic gene expression due to the condensed state of mi totic chromatin.