The spatial organization of ALK3 in adhesion sites is observed in different cell types and does not require BMPRII. (A and B) In (A) REF52 and (B) C2C12 cells without BMP2 treatment, BMPRs were distributed throughout the cell surface and opto-β3 integrin-Venus was targeted within FAs observed on TIRFM. sBMP2 treatment induced the recruitment of ALK3 to FAs, whereas BMPRII remained mainly excluded. Scale bar, 15 µm. (C) The deletion of BMPRII does not impair ALK3 recruitment in focal adhesions. MEF cells are depleted either in BMPRII, ActRIIA, ActRIIB, or all receptors before measuring the level of ALK3 recruitment in FA after BMP2 stimulation. Scr, scramble. N ≥ 136 cells per condition.