Figure 2.

PTCH2 interacts with hedgehogs and SMO. (a) Immunostaining of COS-7 cells transfected with PTCH or PTCH2 and labeled with Shh-IgG or Dhh-IgG (red), and antibody directed against the Flag epitope (green). No labeling was detected in cells transfected with a control vector (data not shown). (b) Competition binding of recombinant murine ¹²⁵I-Shh to 293 cells overexpressing hPTCH or hPTCH2. There was no detectable binding to mock-transfected cells (data not shown). (c) Coimmunoprecipitation of epitope-tagged PTCH or PTCH2 with epitope-tagged SMO. Immunoprecipitation was performed with antibodies to the Flag-tagged PTCH and analyzed by Western blotting on a 6% acrylamide gel with antibodies to the Myc-tagged SMO. Protein complexes can be detected with both PTCH and PTCH2. PTCH and PTCH2 express at similar levels as shown by immunoprecipitation by using antibodies to the Flag tag and by Western blot by using the same anti-Flag antibody.