Figure 5. Mdm2^Y489A antagonizes p53-dependent transactivation and promotes cell survival.

(A) Mdm2^WT or Mdm2^Y489A cells were seeded into 6cm plates and colonies were allowed to form. Cells were then treated with 100 ng/ml Doxycycline for 16h prior to addition of Nutlin for a further 48h. Drug was then replaced with regular medium. Following a further 6 days, cells were fixed and stained with crystal violet. (B) Following extraction with Sorenson’s buffer (50mM sodium citrate, 50mM citric acid in 50% (v/v) ethanol solution), total crystal violet stain was quantified by measuring absorbance at 590nm.