Figure 1.

Phosphorylation of CFTR by Src kinase. Blot of anto-phosphotyrosine immunoprecipitates probed with the anti-CFTR monoclonal antibody L12B4. CFTR peptides (identified by the boundary amino acid numbers indicated above each pair of lanes) co-expressed with or without v-Src and precipitated using monoclonal antibody against phosphotyrosine. Black arrows indicate the positions of CFTR phosphopeptides. The bands at ˜50 and ˜100 kDa observed in every lane indicate mono- and dimeric heavy chains of the immunoprecipitating IgG, which are recognized by the secondary antibody used for immunoblotting. Black arrows indicate CFTR fragments. A representative of 2 experiments is shown.