Fig 1.

The histone deacetylase family. The histone deacetylase family is subdivided into different subfamilies according to homologies to yeast prototypes. Class I HDACs are mainly nuclear and display a zinc-dependent catalytic activity. Class II HDACs are localized both in the nucleus and in cytoplasm. The seven sirtuins in mammals are localized in different subcellular compartments including mitochondria. All sirtuins have a NAD⁺-dependent catalytic core domain that may act preferentially as a mono-ADP-ribosyl transferase (ART) and/or NAD⁺-dependent deacetylase (DAC). SIRT7 exhibits no DAC or ART activities [144]. The class IV HDACs includes HDAC11.