Table 1: Histone deacetylases: Classification and characteristics.

ClassesHDACsLocalizationFeatures

Class IIaHDAC 1, 2Nucleus Related to yeast RPD3 deacetylase Zinc dependent [57]
IbHDAC 3Nucleus & cytoplasm
IcHDAC 8Nucleus

Class IIIIaHDAC 4, 5, 7, 9Nucleus/cytoplasm [58]Related to yeast HdaI Zinc-dependent [23, 24]
IIbHDAC6Cytoplasm
HDAC10Nucleus/cytoplasm [59, 60]

Class III Sirtuins (Sirt1-7)Nucleus, cytoplasm & mitochondriaRelated to the Sir2 NAD+-dependent [25]

Class IVHDAC 11Nucleus & cytoplasmFeatures of both classes I and II [61], Zinc independent