DN Eps15 (A, C, E, G, I, K) or control Eps15 (B, D, F, H, J, L) were transiently expressed in FN-null MFs as described in Methods. (A-D) Transfected cells were seeded onto pre-assembled matrices and incubated for 24 h. Endocytosed fibronectin is shown in (A, B). (E-H) Short-term pulse chase experiments were performed with transfected cells. (E, F) show endocytosed fibronectin following 2 hr of chase. (I-L) The effect of DN and control Eps15 on transferrin receptor endocytosis is shown. Transfected cells were detected by GFP expression (C, D, G, H, K, L) and manually outlined. 15-20 cells were analyzed for each condition; representative images are shown. Scale bar, 10μm.