FIG. 12.
KSR1 affects the ability of site-specific Ras signals to induce senescence. (A) Transforming potential of Ras site-specific signals. MEFs were transfected with vectors encoding H-RasV12 constructs as shown in the inset key (1 μg each) in addition to c-Myc (1 μg). +/+, wild-type MEFs. (B) Site-specific Ras signals require KSR1 to induce senescence. MEFs, wild-type (+/+) or deficient for KSR1 (−/−), were transfected with vectors encoding the H-RasV12 constructs as shown in the inset key in panel A (1 μg each). Where indicated, ectopic KSR1 (1 μg) was also transfected. After 3 weeks, the cells were stained and either the number of foci or the number of senescent cells was scored. Shown are the averages ± standard errors of the means of the results from three independent experiments. +ve, positive.