Figure 5.
Insulin is less able to delay progression through G2 and M phases when nutrients are low. S2 cells seeded at 1 × 106 cells/ml were grown in Schneider's medium that was serially diluted with PBS (before adding 10% FBS) for 24 h. (A) Insulin was added for 15 min and then cell lysates were prepared and analysed by immunoblotting to demonstrate that nutrient depletion reduces basal and insulin-stimulated dS6K phosphorylation. (B) The cells were grown for a further 48 h in 1 μM insulin and then Coulter counter cell count data were recorded. Data shown represent mean data±s.d. from three replicates (*P<0.01) and are representative of three independent experiments.