Mass spectrometry analysis of proteins interacting with STAT3

Mass spectrometry analysis of proteins interacting with STAT3¬Flag was performed. STAT3-Flag was transiently expressed in HeLa cells and the interactome of STAT3-Flag was studied in lysosomal extracts. proteins co-¬immunoprecipitating with STAT3--Flag identified eight subunits of the vacuolar H+-¬ ATPase (V-¬ATPase) as potential STAT3 binding partners. Validation experiments were performed by antibody pull-down of STAT3.