Figure 8.

The activities of the Ptch family proteins are governed, in part, by their adjacent cytoplasmic regions. A, stick diagram illustrating the specific amino acid boundaries of the Ptch1 and Ptch2 constructs. Amino acid numbering refers to the sequences of mPtch1 and mPtch2, respectively. B, specific pairs of N- and C-terminal constructs were tested in the Hh pathway repression assays. When the C-terminal half of Ptch2 containing the cytoplasmic C terminus from Ptch1 (P2-C^P1-CT) was expressed with P1-N or P1-N^ΔML, partial or full repression, respectively, of Hh signaling was observed. However, expression of P2-C^P1-CT with P2-N did not recapitulate the repression activity. Furthermore, the P1-N + P1-C^ΔCT and the P1-N + P1-C^P2-NT combinations showed that the cytoplasmic C terminus of Ptch1 was required but not sufficient for repression activity. *, p < 0.05; **, p < 0.01; ***, p < 0.001.