Expression of the Mgat5/galectin lattice regulates FAK exchange in FAs. Mgat5^+/+ cells were transfected with FAK-GFP and treated with either β-lactose (20 mM) and sucrose (20 mM) (A) or Gal-3 (1 μg/ml) and swainsonine (+SW, 1 μg/ml) (B) and subjected to FRAP analysis of FA localized FAK-GFP. Percent intensity (±SEM) in the bleached zone of FAK-GFP during recovery and quantification of percentage of recovery (box) are shown (±SEM). (C) Mgat5^+/+ cells were either treated with 20 mM lactose, 20 mM sucrose, or 1 μg/ml SW, or transfected with Gal-3, control (CTL), or Cav1 siRNA and then surface labeled at 4°C with anti-Gal-3 mAb and analyzed by FACS. The percentage of positive cells is shown (±SEM; n = 4; *, P < 0.01; **, P < 0.001). (D) Mgat5^+/+ cells not transfected or transfected for 2 d with either control (CTL) siRNA or Gal-3 siRNA were immunofluorescently labeled with Hoechst (blue) and mouse anti-Gal-3 (green) antibodies. Quantification of Gal-3 mean intensity is shown as a bar graph for untreated (white), CTL siRNA (gray), and Gal-3 siRNA transfected (black) Mgat5^+/+ cells (n = 3; ±SEM; *, P < 0.05). (E) Mgat5^+/+ cells were not transfected or transfected for 2 d with either control (CTL) siRNA or Gal-3 siRNA, lysed, and subjected to Western blot analysis for Gal-3, pY14Cav1, Cav1, and β-actin expression. (F) Percent intensity (±SEM) in the bleached zone of FAK-GFP during recovery and percent recovery (box) are shown (n = 3; ±SEM; *, P < 0.05).