Mass Spectrometry-Based Discovery of in vitro Kinome Substrates.

Protein phosphorylation mediated by protein kinases is one of the most significant posttranslational modifications in many biological events. The function and physiological substrates of specific protein kinases, which are highly associated with known signal transduction elements or therapeutic targets, have been extensively studied using various approaches; however, most protein kinases have not yet been characterized. In recent decades, many techniques have been developed for the identification of in vitro and physiological substrates of protein kinases. In this review, I summarize recent studies profiling the characteristics of kinases using mass spectrometry-based proteomics, focusing on the large-scale identification of in vitro substrates of the human kinome using a quantitative phosphoproteomics approach.