Kinases and Dephosphorylases: Chemistry and Roles

Abstract Protein kinases and protein phosphatases catalyze phosphorylation and dephosphorylation of cellular proteins. Posttranslational protein phosphorylation is a major mechanism of signal transduction in eukaryotes; it serves as a reversible switch that alters the activity of target proteins as a means to link stimuli to the appropriate cellular response. In this article, I will review the structures and mechanisms of protein kinases and phosphatases as well as describe chemical tools developed to study protein phosphorylation.