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] , Sirt1 , and Sirt4 .
The genes/proteins involved in insulin biosynthesis and secretion in pancreatic [beta]-cells have been studied: IRE1[alpha] , Sirt1 , Sirt4 , and HuD .
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
, a less studied mitochondrial sirtuin, is an integral part of the metabolic response to genotoxic stress.
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.
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 .
Discovery Reveals Critical Role of SIRT3 and SIRT4
in Cell Metabolism.
is a mitochondrial sirtuin lacking in vitro deacetylase activity .
up arrow] NAMPT, SIRT1, SIRT3, and SIRT4
levels 5 mg/kg, i.