What is the Origin of Sirtuin Proteins?

The name "Sirtuin" is an abbreviation for Silent Information Regulator 2 (Sir2) homolog, initially identified in yeast as a protein involved in gene silencing and lifespan extension. The discovery and characterization of the seven mammalian homologs established their role as central regulators in mammalian physiology and aging pathways.

What is the Mechanism of Sirtuin Proteins?

Sirtuin proteins operate by removing acetyl groups from target proteins, including histones and transcription factors, in a reaction that requires the co-factor Nicotinamide Adenine Dinucleotide (NAD+). SIRT1, for instance, deacetylates PGC-1alpha and other transcription factors, promoting mitochondrial biogenesis and fat metabolism, respectively. Because their activity is directly coupled to NAD+ availability, sirtuins serve as a critical sensor of the cellular energy state, activating protective and repair mechanisms during periods of nutrient scarcity or metabolic stress.

Sirtuin Proteins

Meaning

Sirtuin Proteins, often referred to as longevity proteins, are a family of NAD+-dependent deacetylase and ADP-ribosyltransferase enzymes (SIRT1-SIRT7) that play critical roles in regulating cellular energy metabolism, DNA repair, and stress resistance. These enzymes act as metabolic sensors, linking cellular nutrient status and energy availability to epigenetic regulation and gene silencing. Their activity is a key determinant of cellular healthspan and is closely studied in the context of aging and metabolic disorders.