The coming of age of phosphoproteomics – from large data sets to inference of protein functions

Protein phosphorylation is one of the most common post-translational modifications used in signal transduction to control cell growth, proliferation, and survival in response to both intracellular and extracellular stimuli. This modifi-cation is finely coordinated by a network of kinases and phosphatases that recognize unique sequence motifs and/or mediate their functions through scaffold and adap-tor proteins. Detailed information on the nature of kinase substrates and site-specific phosphoregulation is re-quired in order for one to better understand their patho-physiological roles. Recent advances in affinity chroma-tography and mass spectrometry (MS) sensitivity have enabled the large-scale identification and profiling of protein phosphorylation, but appropriate follow-up ex-periments are required in order to ascertain the func