Fig. 1.

The enzymatic reaction carried out by SirT1, its targets, including transcriptional co-factors, and dependent biological processes. SirT1 protein substrate(s) is represented as a string of blue rectangles, with acetylated (Ac) lysine (K) residues. Using NAD⁺ as a co-factor, SirT1 can deacetylate histones, and nuclear and cytoplasmic proteins on specific K residues. This reaction generates a deacetylated protein, nicotinamide and O-acetyl-ADP-ribose (OAADPR). SirT1 activity can be enhanced by caloric restriction (CR) and by the polyphenol resveratrol, affecting multiple developmental, physiological and pathological processes, and ultimately favoring health and increasing longevity.