TABLE 1.

Characteristics of sirtuins including mass, cellular localization, enzymatic activity, tissues and biological functions.

Sirtuins	Mass (Da) a	Cellular localization	Enzymatic activity	Tissues b	Biological function	References
SIRT1	81,681	Nucleus, cytoplasm	Deacetylase	Low tissue specificity	Regulate oxidative stress and inflammation, aging (life span and health span), calorie restriction/energetics, mitochondrial biogenesis, cellular senescence, endothelial functions, apoptosis/autophagy	(Michishita et al., 2005; Hwang et al., 2013; Singh and Ubaid, 2020; Wang and Chen, 2020)
SIRT2	43,182	Cytoplasm, nucleus	Deacetylase	Enhanced in skeletal muscle, tongue	Neurological function, mitosis regulation, genome integrity, cell differentiation, cell haemostasis, oxidative stress, autophagy	(Michishita et al., 2005; Sayd et al., 2014; Wang et al., 2019b)
SIRT3	43,573	Mitochondria	Deacetylase, Depropionylase	Low tissue specificity	Almost all aspects of mitochondrial metabolism and haemostasis, like urea cycle, TCA cycle, ROS production, apoptosis	(Michishita et al., 2005; Wang et al., 2020; Zhang et al., 2020)
SIRT4	35,188	Mitochondria	Deacetylase, ADP-ribosyltransferase, Lipamidase	Low tissue specificity	Lipid homastasis, Insulin secretion	(Michishita et al., 2005; Haigis et al., 2006; Laurent et al., 2013a; Laurent et al., 2013b; Min et al., 2018)
SIRT5	33,881	Mitochondria	Deacetylase, Desuccinylase, Desmalonylase	Low tissue specificity	Glycolysis, the TCA cycle, fatty acid oxidation, electron transport chain, ketone body formation, nitrogenous waste management	(Michishita et al., 2005; Du et al., 2011; Kumar and Lombard, 2018)
SIRT6	39,119	Nucleus	Deacetylase, Demyristoylase	Low tissue specificity	Heterochromatin stabilization and silencing; stem cell biology; cancer initiation and progression; metabolic homeostasis	(Michishita et al., 2005; Jiang et al., 2013; Tasselli et al., 2017)
SIRT7	44,898	Nucleus	Deacetylase, Desuccinylation	Low tissue specificity	Gene regulation; genome stability; ageing; tumorigenesis	(Michishita et al., 2005; Barber et al., 2012; Li et al., 2016; Blank and Grummt, 2017; Tang et al., 2021)

^aThese data come from the website https://www.uniprot.org/.

^bThis information come from the website https://www.uniprot.org/.