This gene encodes a member of the sirtuin family of proteins, characterized by their deacetylase activity and proposed role in longevity. The encoded protein regulates gene expression in a wide range of cell and tissue types through its NAD+-dependent deacetylation of histones, transcription factors and transcriptional coactivators. Brain-specific overexpression of this gene has been shown to result in increased median lifespan. Viability of homozygous knockout mice for this gene varies with strain background. Homozygous knockout mice of strains that do not exhibit embryonic lethality are sterile and have a reduced lifespan. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2015]