Figure 5. Identification of the region in PITX2 that interacts with EFEMP2. Upper panel: Schematic representation of full-length PITX2C, PITX2A and the PITX2 deletion constructs used in this study. Lower Panel: The HA-PITX2A wild type (WT) and deletion constructs (Δ39–98, Δ99–232 and Δ233–271) were tested for interaction with EFEMP2_ΔN36 using co-immunoprecipitation experiments. All PITX2 constructs (WT, Δ39–98, Δ99–232 and Δ233–271) bound to V5- EFEMP2_ΔN36 were immunoprecipitated with anti-V5 antibody and detected subsequently by immunoblotting using anti-HA antibody. This experiment confirms that the all PITX2 constructs used in this experiment interact with EFEMP2_ΔN36 suggesting that the NH₂-terminal region before the homeodomain in PITX2, commonly shared by all these PITX2 constructs interacts with EFEMP2_N36. Inputs represent 20% of the cell lysates used for immunoprecipitation experiments.