Reversible disruption of pericentric heterochromatin and centromere function by inhibiting deacetylases

Histone modifications might act to mark and maintain functional chromatin d omains during both interphase and mitosis. Here we show that pericentric he terochromatin in mammalian cells is specifically responsive to prolonged tr eatment with deacetylase inhibitors. These defined regions relocate at the nuclear periphery and lose their properties of retaining HP1 (heterochromat in protein 1) proteins. Subsequent defects in chromosome segregation arise in mitosis. All these changes can reverse rapidly after drug removal. Our d ata point to a crucial role of histone under-acetylation within pericentric heterochromatin regions for their association with HP1 proteins, their nuc lear compartmentalization and their contribution to centromere function.