Daam1 participates in the rearrangement of stress fibers in MDA-MB-231 and MCF-7 cells.

(A) N-Daam1 and C3 transferase disrupted the formation of actin stress fibers in MDA-MB-231 cells. MDA-MB-231 cells were transiently transfected with N-Daam1 or pre-treated with 10 ng/µL C3 transferase for 1 h. MDA-MB-231 cells as well as transiently transfected Daam1 mutants were grown on cover slips, and then incubated in culture medium containing 500 ng/mL rWnt5a for 4 h. Subsequently, cells were fixed and F-actin organization was analyzed by phalloidin staining. (C) ΔDAD-Daam1 enhanced the formation/maintenance of actin stress fibers in MCF-7. MCF-7 cells were transiently transfected with ΔDAD-Daam1, and then incubated in culture medium in the absence of Wnt5a. Magnification, ×400. (B, D) The percentage of formation of actin stress fibers was determined in MDA-MB-231 cells (B) and MCF-7 cells (D), as described in Materials and Methods. The average is shown as mean ± s.d.