Figure 3.

FBP17 in RasV12-transformed cells positively regulates the waviness of cell membranes at cell-cell contacts

(A) EM images of RasV12-transformed cells or RasV12 cells stably expressing FBP17-shRNA1. Cells were fixed at 24 hr after the induction of RasV12. The areas in the white boxes are shown as insets at higher magnification, demonstrating intercellular regions.

(B and C) Quantification of waviness of cell membranes (B) and intercellular spaces (C) in RasV12-transformed cells or RasV12 FBP17-shRNA1 cells.

(D) Interdigitation of cell membranes between RasV12 cells in mix culture is diminished by FBP17 knockdown. Cells were fixed at 24 hr after the induction of RasV12. Brackets represent the position of cell-cell contacts.

(E) EM images and tracings of cell membranes showing the interface between normal cells and RasV12 cells (upper panels) or FBP17-knockdown RasV12 cells (lower panels). Cell membranes of normal and RasV12 or RasV12 FBP17-shRNA1 cells are colored in blue and red, respectively. The brackets and arrowheads indicate the position of cell-cell contacts and finger-like protrusions, respectively. (A, D, E) Scale bars, 1 μm; 0.2 μm (inset).

(F) Waviness of cell membranes at each cell-cell contact. The data on the underlined side is shown. (B, C, F) Data are median ±SD. ∗∗p < 0.01 (unpaired two-tailed Student's t-tests).