FIG. 7.

GSK3 is not retained in the Xdsh-XARP complex. Embryos overexpressing HA-Xdsh, HA-Xdd1, HA-Xdsh-Ab, Myc-XARP, and Flag–β-catenin, as indicated, were cultured until early gastrula stages for protein analysis. Each lysate was subjected to two sequential precipitations, first with anti-HA antibodies and then with anti-Myc antibodies. Protein complexes were analyzed by immunoblotting with anti-HA, anti-Myc, anti-GSK3, and anti-Flag antibodies, as indicated. (A) Protein complexes containing XARP in association with Xdsh did not significantly bind GSK3, whereas the pool of XARP that is not bound to Xdsh retained GSK3. (B) The complex of XARP with Xdd1 and Xdsh-Ab, but not with Xdsh, retained GSK3. Protein levels in corresponding embryo lysates are shown (A and B). (C) The Xdsh-XARP complex retains β-catenin. The panel on the right shows that the Xdsh and XARP proteins are not fully depleted from embryo lysates. IP, immunoprecipitation.