Biotinylation of lysine method identifies acetylated histone H3 lysine 79 in Saccharomyces cerevisiae as a substrate for Sir2

摘要

Acetylation, or the addition of an acetyl group to a protein, is a dynamic and reversible posttranslational modification that regulates the function of numerous proteins. This process is, in turn, regulated by the opposing action of acetyltransferases and deacetylases. The Sir2 family of enzymes (sirtuins) comprises a universally conserved class of protein deacetylases that remove the acetyl group from lysines via a process that depends on the coenzyme NAD+ (1) and regulate numerous biological processes. While a number of sirtuin substrates have been identified, most notably for the human sirtuin SirTl (2), these enzymes likely have many more substrates than are currently known. In contrast to acetyltransferases, whose substrates can be identified based on the addition of the acetyl group, identifying new substrates of deacetylases is more challenging because of the greater difficulty in identifying proteins from which a small modification such as an acetyl group has been removed.