Fig. 4. EphA1 inhibits cell spreading in a kinase-activity-dependent manner. (A) Mock, WT-EphA1–FLAG (WT), KD-EphA1–FLAG (KD) and SAM-EphA1–FLAG (SAM) HEK293 cells (see Figs 1 and 2) and EBC-1 cells were plated onto FN-coated (1 µg/ml) coverslips with (right) or without (left) immobilized ephrin-A1–Fc (1 µg/ml) for 30 minutes and stained with rhodamine-conjugated phalloidin. (B) Quantification of spreading in the cells shown in A. (C) GFP images of HEK293 WT-EphA1–GFP cells stimulated by control Fc or ephrin-A1–Fc. (D) HEK293 (293), Rat1 and MCF7 cells expressing GFP or WT-EphA1–GFP were subjected to spreading assays as in A, and stained by phalloidin and DAPI. Only cells after ephrin-A1–Fc stimulation are shown. Scale bars: 10 µm.