Figure 5. AMPK-mediated inhibitory phosphorylation of Acetyl-CoA Carboxylase decreases as the cells divide. HeLa cells, synchronized at early mitosis by thymidine-nocodazole block, were released and harvested every 15 min. The levels of pAMPK and pACC were assessed by western blot (A). The initiation and completion of cytokinesis was determined by counting hourglass-shaped cells and doublets, total cell number and by FACS analysis (B). The incorporation of [¹⁴C] acetate into lipids was estimated with 30 min pulse in nocodazole-blocked (time cero) or released cells (C). HeLa cells were incubated with the AMPK activator MT 63–78 (25 μM) for 24 h in the presence or absence of 100 μM palmitic acid (with BSA in a 2:1 molar ratio), and cell cycle profile was assessed (D). Alternatively, cells were incubated with 20 μg/ml of fatty acid synthase inhibitor (C75) or vehicle (DMSO) for 24 h and pAMPK and pACC levels were assessed by western blot (E).