Fig. 4. R-Ras modulates focal adhesion formation and cell spreading. Hela cells grown on collagen-coated glass coverslips were transfected overnight with pEGFP-Raswt (A,D), pEGFP-R-Ras38V (B, E) and pEGFP-RRas43N (C,F). Note that the R-Raswt cell contains distal focal adhesions, the R-Ras38V cell contains numerous large focal adhesions and the R-Ras43V cell contains few small adhesions. R-Raswt cells were often elongated (D), RRas38V cells (E) well spread and R-Ras43N cells (F) retracted with filopodia-like structures. The number of focal adhesions was calculated from above transfected cells, 15 cells/construct/experiment (J). Results shown are the mean ± s.e.m. of three experiments. Cells expressing EGFP-Raswt, EGFP-R-Ras38V and pEGFP-RRas43N were also plated on collagen-coated coverslips for 60 minutes for estimation of cell spreading (K). 30 cells were counted for each construct and experiment. Results shown are the mean ± s.e.m. of three experiments. Typical spread cells are shown for corresponding construct in G, H and I. Note the numerous large focal adhesions in EGFP-R-Ras38V cells and the few small in EGFP-R-Ras43N cells. Bars, 10 µm.