FIGURE 2.

The proximity of Smo intracellular subdomains is induced by Hh. A, S2 cells were transfected with indicated constructs and treated with or without Hh, respectively. CFP and YFP signals were acquired for FRET before (BP) and after (AP) photobleaching YFP at the top half of each cell (white rectangle frame). B, FRET efficiency is shown from the indicated CFP/YFP-tagged constructs, which were transfected into S2 cells and treated with or without Hh (mean ± S.D. (error bars), n ≥ 30; *, p < 0.05). C, diagram shows the Smo truncations which were used in D and E. D, S2 cells were co-transfected with Myc-tagged or FLAG-tagged full-length Smo (SmoFL) or Smo truncations, respectively. The immunoprecipitation was followed with mouse anti-FLAG antibody, and Western blotting (WB) was followed with rabbit anti-FLAG or anti-Myc antibodies for immunoprecipitation product and cell lysates. Full-length and truncated Smo, beside SmoCT, interact with each other. E, S2 cells were transfected with the indicated constructs, and then native gel electrophoresis was employed. Western blotting shows that full-length and truncated Smo, beside SmoCT, form dimer or oligomer. Arrows point to monomer, and arrowheads point to dimer and oligomer.