Sirtuin Function

Sirtuins belong to the class iii protein deacetylase family which are the only histone deactyalses hdacs that require nad for their enzymatic activity imai et al 2000 nad is an important co factor for the electron transport chain and is also involved in many enzymatic reactions houtkooper et al 2010.

Sirtuin function. These seven mammalian sirtuins regulate. In this chapter we will discuss the different functions and regulation of the mitochondrial sirtuins under stress conditions. Sirtuin genes function as anti aging genes in yeast caenorhabditis elegans and drosophila. Originally characterized in yeast as regulators of life span kaeberlein et al.

We will highlight the aspects of sirtuin biology that are currently unknown and deserve additional research. Members of the sirtuin family are characterized by a sirtuin core domain and grouped into four classes. 1999 the sirtuins are an evolutionarily conserved family of proteins that appear to exert a wide range of biological functions finkel et al. This section only briefly discusses the broad functional diversity of sirtuins and much more information on the topic can be found in the following reviews 5 6 8 12 15 17 27 30 37 39 50 55 mammalian sirtuins occupy different cellular locations act on several substrates and may perform various functions table table1.

The nad requirement for sirtuin function indicates a link between aging and metabolism and a boost in sirtuin activity may in part explain how calorie restriction extends life span. Sirtuins are a class of proteins that possess either mono adp ribosyltransferase or deacylase activity including deacetylase desuccinylase demalonylase demyristoylase and depalmitoylase activity. Sirtuin yeast silent information regulators sir2 was first discovered in the 1970s. 2009 in mammals seven sirtuin family members exist.

The functions of human sirtuins have not yet been determined. The name sir2 comes from the yeast gene silent mating type information regulation 2 the gene responsible for cellular regulation in yeast. In mammals one of the s. Sirtuin subcellular localization and function.

The sirtuin family of proteins. The mammalian sirtuins sirt1 sirt7 are implicated in a variety of cellular functions ranging from gene silencing over the control of the cell cycle and apoptosis to energy homeostasis. Enzymatic activity of sirtuins and nad biosynthesis. Mammals have seven sirtuin proteins denoted as sirt1 through sirt7 each of which exhibits distinct subcellular localization and rather specific functions.

Sirt1 appears to be the closest mammalian homolog to yeast sir2 the first member of. In addition we will discuss the function of mitochondrial sirtuins in the development of numerous pathologies.