Fig. 5.

Inhibition of AMPK does not prevent phosphorylation of Akt by serum starvation but blocks an increase in ATM. Differentiated cells were incubated in serum-containing or serum-free medium in the presence of 20 μM compound C or DMSO (vehicle) for 3 h before extraction in ice-cold lysis buffer. Cell lysates were subjected to SDS/PAGE and then Western blot analysis. A: P-Akt S473 and Akt (n = 3/group). B: P-Akt T308 and Akt (n = 3/group). C and D: P-ATM S1981 (n = 9/group) and ATM (n = 6/group). Data represent means ± SE. *Significant difference due to serum starvation (P < 0.05). †The serum starvation effect is prevented by compound C (P < 0.05).