PP2A_STRIPAK interacts with Slik and regulates its phosphorylation state. (A and B) Cell lysates of S2 cells transiently expressing the indicated cDNA were immunoprecipitated (IP) with anti-GFP (A) or anti-Stag (B) antibodies and analyzed by Western blotting. (C and E) Western blot of S2 cells treated as indicated. (D and F) Line scans of C and E. Arrows indicate Slik-long (Slik-L) or Slik-short (Slik-S). (G) Proportion of phosphorylated Slik (upward shifted/unshifted). Data are represented as mean ± SD of three to five independent experiments (circles). Unpaired t test for drug treatments and one-way ANOVA for dsRNA conditions with the following P values: NS, P > 0.05; *, P < 0.05; **, P < 0.01. λ-PPtase, λ-phosphatase; NT, non-target.