Movie S1.

Wnt treatment induces macropinocytosis-like F-actin cytoskeletal rearrangements at the leading edge of SW480APC cells (a colon cancer cell line SW480 reconstituted with full-length APC). Cells were transfected with Lifeact 24 hours earlier in order to visualize F-actin and filmed for 20 minutes (left panel). In the movie on the right Wnt3a was added and the same cells filmed for an additional 20 minutes. Note that in the controls actin is found in leading edge lamellipodia and filopodia, while after Wnt addition F-actin rapidly surrounds large circular vesicles indicative of macropinocytosis.