Figure 2: pPDFGβR-GRB2-Sos1 coimmunoprecipitation in EqS cell lines. (a) The presence of GRB2 and Sos1 was detected in pPDFGβR immunoprecipitates in higher amount in cell lines EqS01a, EqS02aE5, and EqS04b expressing BPV-1 E5 when compared to EqS02a which do not express the oncoprotein. Actin protein levels were detected on whole cell lysates before immunoprecipitation to ensure equal protein loading and allow normalization. (b) Quantitative densitometric analysis of the bands was performed with Image Lab software (ChemiDoc, Bio-Rad Laboratories).