Although most cancer drugs modulate the activities of cellular pathways by changing post-translational modifications (PTMs), surprisingly little is known regarding the extent and the time- and dose-response characteristics of drug-regulated PTMs. Here, we introduce a proteomic assay termed decryptM that quantifies drug-PTM modulation for thousands of PTMs in cells to shed light on target engagement and drug mechanism of action (MoA). Examples range from detecting DNA damage by chemotherapeutics, to identifying drug-specific PTM signatures of kinase inhibitors, to demonstrating that rituximab...
