Mammal Sirtuins
Seven sirtuins are known in mammals.
- SIRT1 (also known as Sir2α) is the mammal homolog of Sir2. Mice that overexpress SIRT1 show eight properties of calorie restriction, including low cholesterol, low blood glucose, and low insulin levels. They also show increased numbers of mitochondria in their neurons.
- SIRT2 is expressed mainly in the brain.
- SIRT3, SIRT4, and SIRT5 are active in mitochondria, the energy-producing organelles that are a part of every cell.
- SIRT6 is active in the nucleus of the cell.
- SIRT7 is active in the nucleolus, a compartment of the nucleus reserved for the assembly of ribosomes. Sirt7 has been shown to activate RNA polymerase I transcription.
Sir2 was tested on fruit flies.(Diante Thomas)
Read more about this topic: Sir2