Fig. 4. LEF-1 physically interacts with PITX2. (A) GST-LEF-1 pull-down assay with bacterial expressed and purified PITX2A protein (200 ng). PITX2A binds to immobilized GST-LEF-1, showing that PITX2A can physically interact with LEF-1. The bound protein was detected by western blot using the PITX2 antibody, P2R10. As a control GST-beads were incubated with purified PITX2A to show the specificity of binding to LEF-1. (B) GST-ß-catenin and GST-PITX2A pull-down assay with bacterial expressed and purified LEF-1 protein (50 ng). LEF-1 binds to immobilized GST-ß-catenin as expected and used as a positive control. LEF-1 binds to GST-PITX2A in a reciprocal experiment shown in A. The bound protein was detected by western blot using a LEF-1 antibody. As a control, GST-beads were incubated with purified LEF-1 to show the specificity of binding to ß-catenin and PITX2A.