Despite its low cellular abundance, phosphotyrosine (pTyr) regulates numerous cell signaling pathways in health and disease. We applied comprehensive phosphoproteomics to unravel differential regulators of receptor tyrosine kinase (RTK)-initiated signaling networks upon activation by Pdgf-ββ Fgf-2, or Igf-1 and identified more than 40,000 phosphorylation sites, including many phosphotyrosine sites without additional enrichment. The analysis revealed RTK-specific regulation of hundreds of pTyr sites on key signaling molecules. We found the tyrosine phosphatase Shp-2 to be the master regulator of Pdgfr pTyr signaling. Application of a recently introduced allosteric Shp-2 inhibitor revealed global regulation of the Pdgf-dependent tyrosine phosphoproteome, which significantly impaired cell migration. In addition, we present a list of hundreds of Shp-2-dependent targets and putative substrates, including Rasa1 and Cortactin with increased pTyr and Gab1 and Erk1/2 with decreased pTyr. Our study demonstrates that large-scale quantitative phosphoproteomics can precisely dissect tightly regulated kinase-phosphatase signaling networks. Batth et al. use mass spectrometry-based phosphoproteomics to analyze receptor tyrosine kinase signaling activated by different ligands, identifying hundreds of differentially regulated phosphotyrosine sites. Tyrosine phosphatase Shp-2 regulates global tyrosine phosphorylation in a Pdgf-receptor-dependent manner, affecting cellular outcomes.
Batth, T. S., Papetti, M., Pfeiffer, A., Tollenaere, M. A. X., Francavilla, C., & Olsen, J. V. (2018). Large-Scale Phosphoproteomics Reveals Shp-2 Phosphatase-Dependent Regulators of Pdgf Receptor Signaling. Cell Reports, 22(10), 2784–2796. https://doi.org/10.1016/j.celrep.2018.02.038