FIGURE 5.

The RACK1 Tyr-52 mutant suppresses cell adhesion and foci formation. A, MCF-7 cells stably overexpressing HA-RACK1 Y52F were serum-starved for 4 h, removed from plates, resuspended in serum-free medium, and allowed to adhere to collagen for the indicated times. Cells were washed and stained with crystal violet, and absorbance was determined at 595 nm. Data are presented for quadruplicate samples for three individual clones and are representative of that obtained for five clones. B, MCF-7 cells stably overexpressing HA-RACK1 Y52F were seeded in multiple wells of a 6-well plate 24 h after transfection at a density of 500 cells per well and incubated for 14 days at 37 °C. After 14 days cells were stained with Giemsa, the plate was photographed, and the colonies were counted. Data are presented as the mean and S.D. of colonies per well for six wells and are representative of data obtained with five independent clones.