Role of Sirtuins
Histone deacetylases (HDAC) act as transcriptional gene repressors through the deacetylation of lysine residues on histone proteins. They oppose the effect of Histone methyltransferases.
Sirtuins (SIRTs) 1 and 2 are signaling proteins which possess a deacetylase activity (class III HDACs) that require NAD+ as a cofactor.
Sirtuin 1 (SIRT1) is involved in the regulation of tumor suppressor p53 through deactylation, thereby inhibiting apoptosis. It also represents a target for treatment of age-related diseases and type II diabetes.
Sirtuin 2 (SIRT2) is a cytoplasmic protein involved in regulation of cell cycle, DNA repair and tumorogenesis.