Sirtuins were originally shown to regulate a wide array of biological processes such as transcription, genomic stability, and metabolism by catalyzing the NAD(+) -dependent deacetylation of lysine residues. Recent proteomic studies have revealed a much wider array of lysine acyl modifications in vivo than was previously known, which has prompted a reevaluation of sirtuin substrate specificity. ...

Sirtuins are stress-responsive proteins that direct various post-translational modifications (PTMs) and as a result, are considered to be master regulators of several cellular processes. They are known to both extend lifespan and regulate spontaneous tumor development. As both aging and cancer are associated with altered stem cell function, the possibility that the involvement of sirtuins in th...

Silent information regulator 2 proteins (sirtuins or SIRTs) are a group of deacetylases (or deacylases) whose activities are dependent on and regulated by nicotinamide adenine dinucleotide (NAD(+)). Compelling evidence supports that sirtuins play major roles in many aspects of physiology, especially in pathways related to aging - the predominant and unifying risk factor for neurodegenerative di...

Sirtuins are highly conserved NAD(+)-dependent enzymes that were shown to have beneficial effects against age-related diseases. Alzheimer's Disease (AD) is the most common neurodegenerative disorder associated with aging and the effects of sirtuins on AD have been investigated using different mouse and cell culture models. In most of these studies, it has been found that the overexpression of S...

istone deacetylases (HDACs) are enzymes that deacetylate histones, but also act on certain non-histone substrates. Class III HDACs, which are known as sirtuins, catalyze deacetylation of the acetyl-lysine residues of histones using nicotinamide adenine dinucleotide (NAD+) as a cofactor. Silent information regulator 2 (Sir2) was the first gene of the sirtuin family to be discovered. Sir2 shows a...

Brain aging is characterized by progressive loss of neurophysiological functions that is often accompanied by age-associated neurodegeneration. Calorie restriction has been linked to extension of lifespan and reduction of the risk of neurodegenerative diseases in experimental model systems. Several signaling pathways have been indicated to underlie the beneficial effects of calorie restriction,...

The Sirtuins are a family of orthologues of yeast Sir2 found in a wide range of organisms from bacteria to man. They display a high degree of conservation between species, in both sequence and function, indicative of their key biochemical roles. Sirtuins are heavily implicated in cell cycle, cell division, transcription regulation, and metabolism, which places the various family members at crit...

Sirtuins are a conserved family of NAD-dependent protein deacylases. Initially proposed as histone deacetylases, it is now known that they act on a variety of proteins including transcription factors and metabolic enzymes, having a key role in the regulation of cellular homeostasis. Seven isoforms are identified in mammals (SIRT1-7), all of them sharing a conserved catalytic core and showing di...

The yeast transcriptional repressor Sir2p silences gene expression from the telomeric, rDNA, and silent mating-type loci and may play a role in higher order processes such as aging. Sir2p is the founding member of a large family of NAD-dependent deacetylase enzymes, named the sirtuins. These proteins are conserved from prokaryotes to eukaryotes, but most remain uncharacterized, including all se...