Mass spectrometry approaches to study mammalian kinase and phosphatase associated proteins

Reversible phosphorylation events regulate critical aspects of cellular biology by affecting protein conformation, cellular localization, enzymatic activity and associations with interaction partners. Kinases and phosphatases interact not only with their substrates but also with regulatory subunits and other proteins, including scaffolds. In recent years, affinity purification coupled to mass spectrometry (AP–MS) has proven to be a powerful tool to identify protein–protein interactions (PPIs) involving kinases and phosphatases. In this review we outline general considerations for successful AP–MS, and describe strategies that we have used to characterize the interactions of kinases and phosphatases in human cells.