Figure 5.
Increasing levels of hMDMXp60 induces oscillation in hMDM2 expression levels in H1299 cells. (A) Expression of a fixed amount of hmdm2 and increasing levels of either (a) hMDMXp60 alone or (b) together with a fixed amount of hmdmxfl, or (c) increasing levels of both isoforms. The hmdm2(C464A) mutant (d) is E3 ligase dead and is not affected by hMDMXp60 (Fig. S4A and B). (B) In vitro autoubiquitination of recombinant hMDM2 in the presence of increasing levels of hMDMXp60. Data shows one representative experiment out of 3 (Fig. S5A and B).