Validation of protein phosphorylation by immunoprecipitation-immunoblot analysis of R390A and D388N c-Src SYF cells after treatment with 10 mm for 5 min. Immunoprecipitation was carried out with commercially available antibodies corresponding to the protein of interest and immunoblotting was carried out with the 4G10 Tyr(P) antibody as well as protein-specific antibodies. Vimentin, C3G, tensin, matrin, nucleophosmin, and GSK-3β are some novel potential direct c-Src substrates that were validated by immunoprecipitation-immunoblot analysis.