Fig. 5. Kermit interacts with Xfzs in vitro and in Xenopus embryos. (A) In vitro binding: Xfz3, Xfz7 and Xfz8 C-termini purified as GST-fusion proteins were incubated with ³⁵S-labeled Kermit (in vitro translated). Autoradiography (top panel) shows that Kermit bound strongly to the Xfz3 C terminus and weakly to Xfz7, but not to Xfz8. The lower panel shows Coomassie Brilliant Blue staining of the GST fusion proteins. (B) Co-immunoprecipitation of Kermit and Xfz3. Embryos were injected at the one-cell stage with mRNAs encoding Xfz3 and Myc-tagged Kermit, and cultured until the late blastula stage. Xfz3/Kermit complexes were immunoprecipitated from embryo lysates with anti-Myc antibody and Xfz3 was visualized by Western blotting.