Notably, the distribution of some isoforms (e.g., SIRT1, SIRT2, SIRT3, and
SIRT5) is varied due to their specific activity [2].
SIRT1, SIRT6, and SIRT7 are found in the nucleus; SIRT3, SIRT4, and
SIRT5 are found in the mitochondria; and SIRT2 is primarily found in the cytoplasm (21).
SIRT1 and
SIRT5 activity expression and behavioral responses to calorie restriction.
Although
SIRT5 was identified as a responsible "eraser" for lysine succinylation in mitochondria [17, 18], the enzymes that regulate histone lysine succinylation in the nucleus remain elusive.
In humans, 18 HDACs have been discovered and they are classed into four main families: class I (HDACs 1, 2, 3, and 8), class II (HDACs 4, 5, 6, 7, 9, and 10), class III (SIRT1, SIRT2, SIRT3, SIRT4,
SIRT5, SIRT6, and SIRT7), and class IV (HDAC11) [20].
The HDACs are grouped into four classes: class I (HDACs 1,2, 3, and 8), class II (HDACs 4,5, 6,7,9, and 10), class III (SIRT1, SIRT2, SIRT3, SIRT4,
SIRT5, SIRT6, and SIRT7), and class IV (HDAC11) [74, 75].
Gene Symbol Description FC DLAT Dihydrolipoamide -1,678 S-acetyltransferase HSPB7 Heat shock protein family B -1,422 (small) member 7 LPIN1 Lipin 1 -1,838 MECP2 Methyl-CpG binding protein 2 -1,22 NDUFS3 NADH: ubiquinone oxidoreductase -1,314 core subunit S3 NT5C 5', 3'-nucleotidase, cytosolic -1,524
SIRT5 Sirtuin 5 -1,255 YWHAQ Tyrosine 3-monooxygenase/tryptophan -1,364 5-monooxygenase activation protein theta
[sup][10] Recently, it has been found that
SIRT5 displays demalonylase and desuccinylase activity by removing malonyl or succinyl moiety from target protein, such as carbamoyl phosphate synthase 1.