Fig. 4. Phosphorylation of Cx50 on serines and threonines stimulated by H₂O₂ or TPA in lenses from the control, but not the PKC knockout mice. Cx50 were immunoprecipitated from the lens whole cell extracts from 12-O-tetradecanoylphorbol 13-acetate (TPA) or H₂O₂ treated or untreated control or PKC knockout (KO) lenses, and the protein complexes were resolved by 4%-15% SDS gradient gels and immunoblotted with anti-phosphoserine (pS), or anti-phosphothreonine (pT), or anti-Cx50 antisera. Phosphorylation of Cx50 on Ser and Thr are shown. Cx50 was measured as a loading control. NS, non-specific IgG, is a negative antibody binding control. Results are representative of three experiments. KO, PKC knockout; PBS, phosphate-buffered saline; IP, immunoprecipitation; IB, immunoblot.