Independence of mechanisms of PI 3-K activation in response to Epo stimulation.

All mechanisms of PI 3-K activation in response to Epo stimulation are independently able to activate the PI 3-K/Akt/FKHRL1 and mTOR/P70S6K pathways. Lysates from 32D cells expressing either a normal EpoR or a mutant form of the receptor (EpoR Tyr1, Tyr1-7, Phe1-Phe2-Tyr3-8), stimulated with Epo at 10 U/mL for 10 minutes, in the absence or presence of LY294002 at 50 μM, were analyzed by Western blot with anti-pAkt (Ser473), anti-pP70S6K (Thr389), and anti-FKHRL1 (Thr32) antibodies.