SIRT1 and endocrine signaling

Sirtuins (Sir2-related enzymes) are a recently discovered class of NAD+-dependent protein deacetylases that regulate gene expression in a variety of organisms by deacetylation of modified lysine residues on histones, transcription factors and other proteins. Conservation of sirtuin regulation of the insulin–insulin-like growth factor I signaling pathway has been observed for Caenorhabditis elegans and mammals, indicating an ancient role for sirtuins in the modulation of organism adaptations to nutritional intake. The human sirtuin SIRT1 regulates a number of transcription factors that modulate endocrine signaling, including peroxisome proliferator-activated receptor γ, peroxisome proliferator-activated receptor γ coactivator 1α, forkhead-box transcription factors and p53.