Fig. 2

The 9 cell lines differ by cortactin subcellular localization but not by its phosphorylation extent. Cell lines were tested for cortactin distribution by confocal microscopy (A–C) and expression and activation by Western blots (D–F). A–C Confocal images of cell lines plated on fibronectin-coated coverslips, serum-starved for 2 h, then stimulated 4 h with serum-containing medium and (immuno)labeled with anti-Cortactin and anti-GM130 (Golgi; A), anti-Paxillin (focal adhesions; B) or Phalloidin (F-actin; C) and Hoechst (nuclei). Blue and white insets, perinuclear and edge regions respectively. Yellow, orange and white arrowheads, cortactin distribution in Golgi region, focal adhesions and cell edge protrusions, respectively (n = 1–3). D Western blots of cortactin and phosphorylated cortactin (pCortactin Y421) with both isomers at 80 kDa and 85 kDa in the 9 cell lines. GAPDH was used as loading control. E, F Quantification of total cortactin (80 + 85 kDa forms) protein abundance (E) and phosphorylation level of the 85 kDa form (ratio of pCortactinY421/cortactin; F) in the 9 cell lines (n = 2–6)