Table 1. Mammalian sirtuin family members.
| Enzymatic activity | Subcellular localization | Function | |
|---|---|---|---|
| Sirt1 | Deacetylase | Nuclear, Cytoplasmic | Glucose production (liver) Cholesterol regulation (liver) Fatty acid mobilization (WAT) Adipokine regulation (WAT) Fatty acid oxidation (skeletal muscle) Insulin secretion (pancreatic β cells) Neuroprotection (brain) Regulation of cellular differentiation Stress resistance&apoptosis control Mediator for caloric restriction? |
| Sirt2 | Deacetylase | Cytoplasmic, Nuclear | Tublin deacetylation Cell cycle control |
| Sirt3 | Deacetylase | Mitochondrial, Nuclear | Mitochondrial protein deacetylation Acetate metabolism regulation Thermogenesis (BAT)? |
| Sirt4 | ADP-ribosyltransferas e | Mitochondrial | Amino acid-stimulated insulin secretion (pancreatic β cells) |
| Sirt5 | Deacetylase | Mitochondrial | Unknown |
| Sirt6 | ADP-ribosyltransferase Deacetylase | Nuclear | Base excision repair Telomeric chromatin structure |
| Sirt7 | unknown | Nucleolar | Pol I transcription? |