The chemical reagent pervanadate is widely used to study phosphotyrosine signaling because it is a potent, irreversible inhibitor of protein tyrosine phosphatases that globally increases tyrosine phosphorylation across the proteome. In this issue of Science Signaling , Mulholland et al. show that pervanadate also modulates phosphotyrosine signaling by oxidizing specific cysteine residues on the tyrosine kinase SRC, thereby leading to hyperactivation of this ubiquitous signaling enzyme.
Neel H. Shah (Tue,) studied this question.