(redirected from Sirt4)
Also found in: Medical.


 (sûr′to͞o-ĭn, -tyo͞o-)
Any of a family of enzymes that occur in all living organisms and are thought to regulate cellular aging, apoptosis, and resistance to stress in more complex eukaryotic organisms.

[Alteration of Sir2, name of the first gene coding for the synthesis of such enzymes to be isolated (short for s(ilent mating-type) i(nformation) r(egulation) 2, so called because the gene silences the expression of genes relating to the two mating types of the yeast from which it was isolated ) + -in.]


a protein that regulates cell metabolism and ageing
References in periodicals archive ?
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).
The genes and proteins involved in direct regulation of insulin biosynthesis and secretion in pancreatic [beta]-cells have been reported: IRE1[alpha] [21], Sirt1 [22], and Sirt4 [23].
The genes/proteins involved in insulin biosynthesis and secretion in pancreatic [beta]-cells have been studied: IRE1[alpha] [21], Sirt1 [22], Sirt4 [23], and HuD [13].
SIRT4 and SIRT6 function as mono-ADP-ribosyltransferases, which transfer the ADP-ribosyl moiety to the substrate protein including glutamate dehydrogenase 1, poly (ADP-ribose) polymerase 1 respectively.
The mitochondria contain three of the seven mammalian sirtuins, including SIRT3 and SIRT4.
SIRT4, a less studied mitochondrial sirtuin, is an integral part of the metabolic response to genotoxic stress.
SIRT4 inhibits glutamate dehydrogenase and opposes the effects of calorie restriction in pancreatic [beta] cells.
A study by Sirtris Scientific Advisory Board members and Harvard University scientists, published in the journal Cell in September 2007, showed for the first time that activation of SIRT3 and SIRT4 protects against cell damage.
SIRT4 is also a lipoamidase that hydrolyzes the lipoamide cofactors from the E2 component of the pyruvate dehydrogenase (PDH) complex, which reduces the activity of the complex [142].
Discovery Reveals Critical Role of SIRT3 and SIRT4 in Cell Metabolism.
Sirt4 is a mitochondrial sirtuin lacking in vitro deacetylase activity [16].
up arrow] NAMPT, SIRT1, SIRT3, and SIRT4 levels 5 mg/kg, i.