Fig. 7. Ephrin-B1–Fc-induced retraction is antagonized by a peptide that selectively binds to EphB2 and blocks ephrin binding. (A) Representative examples of cell morphologies are shown. Upon treatment with 1.5 µg/ml ephrin-B1–Fc, medullary tubule cells retracted at the periphery, leaving behind spike-like protrusions (arrows). Preincubation of cells with the SNEW peptide inhibited cell retraction induced by ephrin-B1–Fc, whereas a control peptide that does not bind any Eph receptor did not inhibit cell retraction. (B) Quantitation of the percent of cells with spike-like protrusions with or without ephrin-B1–Fc and in the presence or absence of 360 µM SNEW peptide is shown. Data from four independent experiments are shown as mean ± s.d.