Induction of the proximity between ALK3 and β3 integrin in mesenchymal and epithelial cell lines. Representative images showing ALK3 targeting FAs before (A) and after 3 min of blue light stimulation (B) in the C2C12, MEsv40, REF52, and Eph4 cell lines. Scale bar, 15 µm. (C) Profile of the normalized increase in the intensity of opto-ALK3-RFP at FA sites over time upon blue-light illumination. All mesenchymal and epithelial cell lines showed a similar recruitment profile. The mean ± SD is shown for 10 cells.