Permeability of Dictyostelium discoideum to fucose and uracil following growth-arrest induced by starvation, hadacidin, and cerulenin.
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.
D000935:Antifungal Agents / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002569:Cerulenin / Q000494:pharmacology*; D004023:Dictyostelium / Q000187:drug effects* / Q000378:metabolism; D005643:Fucose / Q000378:metabolism*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010873:Pinocytosis / Q000187:drug effects; D013217:Starvation; D014498:Uracil / Q000378:metabolism*
D000935:Antifungal Agents; D002569:Cerulenin; D005643:Fucose; D014498:Uracil; C001321:hadacidin; D005998:Glycine