Direct binding of Sdt to Baz is regulated by phosphorylation of BazS980. (a) Purified fusion proteins used for in vitro binding assays stained with Coomassie. (b) Western blot of GST pull-down experiment. (c) Coimmunoprecipitation of endogenous embryonic proteins in the absence or presence of the phosphatase inhibitor cantharidin. IP, immunoprecipitation. (d) Coimmunoprecipitation after transfection of GFP-Baz and Sdt-myc into S2R+ cells. (e) Mapping of the binding site of Baz for Sdt. GFP-Baz and deletion versions of Baz were cotransfected into S2R+ cells with Sdt-PDZ-myc. (f) Coimmunoprecipitation after cotransfection of GFP-Baz or GFP-BazS980A with Sdt-myc into S2R+ cells in the absence (−) or presence (+) of cantharidin. (g) Coimmunoprecipitation after cotransfection into S2R+ cells of Sdt-PDZ-myc with GFP-tagged versions of Baz.