Figure 5. ALK3 forms homodimers in the absence of exogenous ligand and ALK2/3 heterodimers in presence of BMP6.
Huh7 cells were transfected with plasmids as indicated. Co-immunoprecipitation was carried out with Flag beads or HA-Beads followed by western blotting with α-HA antibodies, as indicated. To test transfection and precipitation efficiency, blots were probed with α-Flag or α-HA antibody (n=3). Co-immunoprecipitation, without addition of ligand, of (A) ALK3-Flag and ALK3-HA, (B) ALK3-HA and ALK2-Flag, and (C) ALK2-Flag and ALK2-HA is shown. Co-immunoprecipitation, after addition of BMP6 or BMP2, of (D) ALK2-HA and ALK2-Flag, (E) ALK2-HA and ALK2-Flag, and (F) ALK2-Flag and ALK3-HA is shown. Input (In), Immunoprecipitation (Ip).