2.3.1.286 phosphoprotein - 739439 2.3.1.286 phosphoprotein phosphorylation of Thr522 is an important allosteric mechanism to activate SIRT1 in response to stress. While non-phosphorylation of this residue leads to formation of less-active oligomers, phosphorylation helps to maintain the monomeric status of SIRT1, resulting in increased activity 730947