Induction of phosphotyrosine in the gap junction protein, connexin43 1A preliminary part of these data was presented at the IV European Congress of Cell Biology, Prague, Czech Republic, 26 June–1 July 1994 [49].1

AbstractThe protein-tyrosine phosphatase inhibitors pervanadate, permolybdate, H2O2, and to a much lesser extent vanadate, increased the amount of cellular phosphotyrosine and induced tyrosine phosphorylation of connexin43 (Cx43) in early passage hamster embryo fibroblasts. The presence of phosphotyrosine in Cx43 immunoprecipitates from pervanadate-treated cells was shown by a phosphotyrosine-specific antibody and a phosphotyrosine-specific phosphatase. Pervanadate-induced Cx43 tyrosine phosphorylation was further verified by phosphoamino acid analysis, while no phosphotyrosine was present in control cells. This is the first observation of tyrosine phosphorylation of connexins in normal cells