Abstract
Kinases are one of the most important families of enzymes that are involved in numerous cell signaling processes. Existing methods for studying kinase expression and activation have limited kinome coverage. Herein we established a multiple-reaction monitoring (MRM)-based targeted proteomic method that provided an unprecedented coverage (∼80%) of the human kinome. We employed this method for profiling comprehensively the alterations of the global kinome of HEK293T human embryonic kidney cells upon treatment with methylglyoxal, a glycolysis byproduct that is present at elevated levels in blood and tissues of diabetic patients and is thought to contribute to diabetic complications. Our results led to the quantification of 328 unique kinases. In particular, we found that methylglyoxal treatment gave rise to altered expression of a number of kinases in the MAPK pathway and diminished expression of several receptor tyrosine kinases, including epidermal growth factor receptor (EGFR), insulin growth factor 2 receptor (IGF2R), fibroblast growth factor receptor (FGFR), etc. Furthermore, we demonstrated that the diminished expression of EGFR occurred through a mechanism that is distinct from the reduced expression of IGF2R and FGFR1. Together, our targeted kinome profiling method offers a powerful resource for exploring kinase-mediated signaling pathways that are altered by extracellular stimuli, and the results from the present study suggest new mechanisms underlying the development of diabetic complications.