cerulenin and Starvation

Topics: Adenosine Triphosphate; Bacillus subtilis; Cerulenin; Fatty Acid Synthesis Inhibitors; Fatty Acids; Guanosine Triphosphate; Ligases; Membrane Potentials; Starvation; Stress, Physiological

The uptake of fucose and uracil by Dictyostelium discoideum in either a starvation or drug-induced growth-arrest state was studied. For both nutrients, the uptake was an energy-dependent process. The rate of fucose uptake remained constant for over four hours, while the uracil rate declined after about one hour, in starvation-induced growth-arrest. Under these conditions, fucose was found to be incorporated into membrane-associated glycoproteins and glycolipids, while uracil was incorporated into RNA. The rate of fucose uptake was the same for starvation or hadacidin-induced growth-arrest, but significantly lower for cerulenin-treated cells. In contrast, uracil uptake was slower in hadacidin-treated cells as opposed to starvation or cerulenin-induced growth-arrest cells. Further experiments showed that the incorporation rate of uracil into RNA was faster in hadacidin-treated cells than controls, and the cerulenin-treated cells were slower. The data suggest that the cells arrested in growth by nutrient deprivation retain the capacity to take-up and incorporate nutrients such as fucose and uracil and that pinocytosis is probably the process responsible for uptake.

Topics: Antifungal Agents; Biological Transport, Active; Cell Division; Cell Membrane Permeability; Cerulenin; Dictyostelium; Fucose; Glycine; Pinocytosis; Starvation; Uracil