FIG. 9.

Abnormal junctions in Nap1-depleted cells are rescued by overexpression of the Dia1 actin polymerization domains. (A) 293T cells or A431 cells expressing the indicated EGFP-Dia1 proteins were lysed, and endogenous Nap1 was immunoprecipitated with anti-Nap1 antibodies (middle row of panels). The coimmunoprecipitated EGFP-Dia1 proteins were detected with anti-GFP antibodies (top panels), and endogenous Abi1 was detected with anti-Abi1 antibodies (bottom panels). (B) A431 cells were lysed, and endogenous Nap1 was immunoprecipitated with anti-Nap1 antibodies. Coimmunoprecipitated endogenous Dia1 and Abi1 proteins are shown. (C) A431 cells expressing GFP alone or GFP-Dia1 (FH1-FH2) were transfected with Nap1 or control siRNAs. After 48 h, cells were fixed and stained with anti-β-catenin antibody (bar, 30 μm). (D) Quantification of cells with mature or abnormal junctions. Results represent the means ± SEMs of at least three independent experiments. *, significant decrease or increase for control siRNA versus Nap1 siRNA (P < 0.01); +, significant increase or decrease for Nap1 siRNA versus Nap1 siRNA + Dia1 (FH1-FH2) (P < 0.01).