While class I HDACs are localized predominantly within the nucleus, class II HDACs shuttle into and out of the nucleus in response to intracellular signaling. Class IIa HDACs, which includes HDAC4, 5, 7, and 9, commonly act as corepressors and play diverse roles in cell biology. MC 1568 is a selective inhibitor of class IIa HDACs, with greater than 170-fold selectivity over class I HDACs, including HDAC1. It has been used in cells (1-10 μM) and in mice to elucidate the roles of class IIa HDACs in cell proliferation and differentiation, apoptosis, myogenesis, adipogenesis, and fibrosis.
