Ecad oligomerization increases the anchoring of cadherin adhesions. (A) Magnetic tweezers experimental setup. A pointed iron tip is wrapped with a copper coil under tension to generate a magnetic field in the vicinity of beads. 2.8 µm of Ecad-Fc–coated magnetic beads were preincubated 1 h on wt Ecad or cis-Ecad expressing A431D cells, and then the unbound beads were washed away. A 10-V magnetic field was applied during 10 s in the vicinity of a bound bead, and then the magnetic power was turn off for 240 s while acquiring phase-contrast images to follow bead displacement. Beads were tracked during and in between the application of forces. This sequence was repeated six times over each analyzed bead. (B) Distribution in three classes (release, displacement, and immobility) of the responses to the magnetic field of Ecad-Fc–coated beads bound to wt Ecad (39 cells) and cis-Ecad (54 cells) expressing cells. (C) Bead displacement under force: representative traces of the displacement from origin of single beads bound to wt Ecad cells and cis-Ecad cells, respectively, in response to six successive cycles of magnetic force application. (D) Curves showing the mean displacement from the origin in response to forces of beads bound to wt Ecad cells (77 displacements measured on 12 independent beads) and cis-Ecad cells (72 displacements measured on 12 independent beads). (E) Bead displacement under zero force: successive trajectories (125 s long) undergone by a single bead bound to wt Ecad and cis-Ecad expressing cells, respectively, during the six successive steps of force release. Data shown are representative of the behavior of 12 beads for each condition. (F) MSD in the absence of force calculated over the six cycles for n = 12 beads attached to wt Ecad (gray) and cis-Ecad (black) expressing cells.