Figure 7.

Disassembly of Cell-Matrix Adhesionss at the Contact Is Required for Separation.

(A) TFM of cells expressing membrane RFP (gray) outlined (gray) and substrate displacement vectors color coded to their magnitude. Control and PF-573228 (FAK inhibitor) treated cells.

(B) Traction force magnitude at the free edge and at the contact. n = 24 cells for both conditions.

(C) Schematic of tension across cell-cell contact inferred from the balance of forces: traction at free edge (a), traction near the contact (b), tension across the contact (τ).

(D) Tension across the contact. Control, n = 39; PF-573228, n = 18 cells.

(E) FRET efficiency at cell-cell contact from vinculin-tensor sensor in control and PF-573228 treated cells.

(F) FRET efficiency at the cell-cell contact.

(G–I) Schematic of cells under the indicated ablations. Below: frames from movies after collisions. Cells expressing membrane RFP (gray) and GFP-FAK (green in zoom). Zoom of cell-cell contact. Ablation area marked with a yellow box on zoom. To maintain the same orientation and scale, images in G–I were rotated, zoomed, and the background was filled with black.

(J) Length of the cell-cell contact relative to the start of laser ablation (0 min). Yellow area shows time of laser ablation. n = 15 doublets for control no ablation (blue), PF-573228 no ablation (orange), and PF-573228 CCA ablation (purple). PF-573228 CMA ablation n = 18 doublets (green).

(K) Cells expressing membrane GFP and nuclear RFP treated with the ROCK inhibitor Y-27632.

(L) Percentage of cells that undergo CIL after colliding.

(M) Duration of contact; 87 cell collisions analyzed in four independent experiments.

(N) Model summarizing main results. Red dotted rectangle is shown as zoom in i, ii, and iii.

Scale bars, 20 μm. Bar graphs show means, errors ± SEM. Line graph shows medians. ^∗∗∗p ≤ 0.001, ^∗∗p ≤ 0.01, ^∗p ≤ 0.05. (B and D) Mann-Whitney test, (F and L) t test, (J) ANOVA test.