Assay to visualize specific protein oxidation reveals spatio-temporal regulation of SHP2

Reactive oxygen species (ROS) are produced transiently in response to cell stimuli, and function as second messengers that oxidize target proteins. Protein-tyrosine phosphatases (PTPs) are important ROS targets, whose oxidation results in rapid, reversible, catalytic inactivation. Despite increasing evidence for the importance of PTP oxidation in signal transduction, the cell biological details of ROS-catalyzed PTP inactivation have remained largely unclear, due to our inability to visualize PTP oxidation in cells. By combining proximity ligation assay (PLA) with chemical labeling of cysteine residues in the sulfenic acid state, we visualize oxidized Src homology 2 domain-containing protein-tyrosine phosphatase 2 (SHP2). We find that platelet-derived growth factor (PDGF) evokes transient oxidation on or close to RAB5+/EEA1-endosomes. SHP2 oxidation requires NADPH oxidases (NOXs), and oxidized SHP2 co-localizes with PDGF receptor and NOX1/4. Our data demonstrate spatially and temporally limited protein oxidation within cells, and suggest that PDGF-dependent \"redoxosomes,\" contribute to proper signal transduction.