Bcr-Abl targets p27 to proteasomal degradation via both PI3K dependent and independent mechanism.

Western blot of total cell lysates from Ba/F3 cells expressing the temperature sensitive Bcr-Abl. (A) Cells were cultivated without growth factor for 5 hours either at the nonpermissive temperature (39°C) or at the permissive temperature (33°C) in the presence or absence of 10 μmol/L Lactacystin after incubation at 39°C without IL-3 for 14 hours. (B) Cells were incubated at 39°C in the absence of IL-3 for 14 hours (0 hour 39°C), followed by an incubation for 5 hours at the permissive temperature 33°C in the absence (5 hours 33°C) or presence of 5 μmol/L LY294002 (5 hours 33°C LY).