Table 1.
Known targets and functions of the mammalian Sir2 family of proteins (sirtuins)
| Sirtuin | Cellular location | Protein modifieda | Amino acid modified | Cellular function |
|---|---|---|---|---|
| SIRT1 | Nucleus | Histone H3 | 9, 14 | DNA packing, gene transcription |
| Nucleus | Histone H4 | 16 | DNA packing, gene transcription | |
| Nucleus | Histone H1 | 29 | DNA packing, gene transcription | |
| Nucleus | p53 | 320, 382 | Cell survival | |
| Cytoplasm | Ku70 | 539, 542 | Cell survival | |
| Nucleus | NF-κB(p65) | 310 | Cell survival/anti-inflammatory? | |
| Nucleus | HIV Tat | 50 | HIV replication | |
| Nucleus | p300 | 1020, 1024 | Gene transcription | |
| Nucleus | TAF I 68 | ? | Gene transcription | |
| Nucleus | MyoD | ? | Muscle development | |
| Nucleus | NCOR | ? | Fat metabolism | |
| Nucleus | FOXO1/3/4 | ? | Glucose metabolism/cell defenses | |
| Nucleus | PGC-1α | ? | Glucose metabolism | |
| SIRT2 | Cytoplasm | Tubulin | ? | Cytoskeleton |
| SIRT3 | Mitochondria | ? | ? | Thermogenesis? |
| SIRT4 | Mitochondria | ? | ? | ? |
| SIRT5 | Mitochondria | ? | ? | ? |
| SIRT6 | Nucleus | SIRT6? | ? | Base excision repair |
| SIRT7 | Nucleolus | RNA PolI | rRNA transcription |
a
SIRT1,2,3,5,7 possess deacetylase activity; SIRT4 and 6 possess ADP-ribosyltransferase activity.