The activity of SIRT1 is regulated by several post-translational modifications, including phosphorylation. Here we provide a diagram illustrating the phosphorylation sites of SIRT1 by several protein kinases. Kinases depicted in green increase the enzymatic activity of SIRT1 upon phosphorylation. The kinase depicted in red, MST1, inhibits SIRT1 activity. CHK1, checkpoint kinase 1; CK2, casein kinase II; DYRK1/3, dual specificity tyrosine phosphorylation-regulated kinase 1/3; JNK, c-jun N-terminal kinase 1; S, serine; T, threonine.