Deleted in breast cancer 1 (DBC1) has emerged as an important regulator of multiple cellular processes, ranging from gene expression to cell cycle progression. DBC1 has been linked to tumorigenesis both as an inhibitor of histone deacetylases (HDAC), HDAC3 and sirtuin 1 (SIRT1), and as a transcriptional cofactor for nuclear hormone receptors. However, despite mounting interest in DBC1, relatively little is known about the range of its interacting partners and the scope of its functions.

DBC1 levels were measured by SRM-MS using an Orbitrap Velos in wild-type CEM T, HEK 293, MRC5 fibroblast, and U2OS cells, as well after over expression of either EGFP or EGFP-tagged DBC1 in CEM T and HEK 293 cells. Each cell type/line was measured in triplicate using three DBC1 tryptic peptides for protein level quantification. Histone H2A and H2B (one tryptic peptide from each protein) were used for global normalization.