PATJ associates with Myosin in vitro and in vivo. (A) Segmental overexpression of PATJ-HA stabilizes a Sqh protein, which cannot be phosphorylated, at the AJ (SqhAA-GFP). (B) Endogenous Zip can be copurified together with PATJ from embryonic lysates. Both blots are from the same gel. (C) Coimmunoprecipitation of PATJ-GFP and Sqh-myc from transfected S2R+ cells. (D) GST-PATJ directly associates with MBP-Sqh in a MBP pull-down assay. (E) Overexpression of wild-type Sqh but not of a phosphorylation-deficient version (SqhAA) can partly rescue PATJ mutant embryonic lethality. Lethality data were averaged from three different experiments with 100 embryos each. IP, immunoprecipitation; UAS, upstream activation sequence. Error bars show SDs. Bar, 10 µm.