Figure 1. Sirtuin enzymatic activities.
Sirtuins are NAD+-dependent deacetylases and mono-ADP-ribosyl transferases that regulate a wide array of proteins involved in metabolism and cell survival. The ε-acetyl lysine residues of the target protein serve as substrates for sirtuin deacetylation, which generate 2′-OAADPr as a by-product. NAM, nicotinamide.