Serine is a new target residue for endogenous ADP-ribosylation on histones.
Leidecker O., Bonfiglio JJ., Colby T., Zhang Q., Atanassov I., Zaja R., Palazzo L., Stockum A., Ahel I., Matic I.
ADP-ribosylation (ADPr) is a biologically and clinically important post-translational modification, but little is known about the amino acids it targets on cellular proteins. Here we present a proteomic approach for direct in vivo identification and quantification of ADPr sites on histones. We have identified 12 unique ADPr sites in human osteosarcoma cells and report serine ADPr as a new type of histone mark that responds to DNA damage.