Figure 7.

Suppression of growth. Saos-2 cells were transfected with pC53-SN3 as before, but were seeded at only 1×10⁵ cells per 60 mm dish. Cells were washed 16 h after transfection and were treated with G418 at 400 μg ml⁻¹ after 48 h. The cells were left for 4 weeks and the number of colonies produced was then counted. The results show that the two mutant proteins (344P and the 7 base pair insertion) produced the most colonies in this experiment. Indeed, the number of colonies was identical for these two mutants. As the 344P mutant is known to be functionally dead, this demonstrates a complete lack of suppression of growth by the 7 base pair insertion mutation.