title: A mouse leukemia cell mutant resistant to blasticidin S.
abstract: After nitrosoguanidine mutagenesis we isolated from mouse leukemia L5178Y cells a mutant cell (Bla-R) resistant to blasticidin S, an inhibitor of protein synthesis. Neither growth nor leucine incorporation into hot-acid insoluble fraction of Bla-R cell was inhibited by 5 to 20 microgram/ml blasticidin S, which almost completely blocked protein synthesis as well as growth of the parental L5178Y cells. However, other inhibitors such as fusidic acid, cycloheximide, ricin D or L-asparaginase blocked protein synthesis in Bla-R cells to the same extent as in L5178Y cells. Protein synthesis in vitro using S-30 extracts from the parental cell line L5178Y was almost completely blocked in the presence of the antibiotic, while no inhibition by blasticidin S occurred when S-30 extracts -rom Bla-R mutant cells were used. Protein synthesis assays were made by using the S100 fraction from rat liver together with ribosomes from either L5178Y cells or Bla-R cells. Blasticidin S inhibited protein synthesis when ribosomes were derived from L5178Y cells, but not from Bla-R mutant.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001215:Asparaginase / Q000494:pharmacology; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D005672:Fusidic Acid / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology*; D007942:Leukemia, Experimental / Q000276:immunology*; D051379:Mice; D009154:Mutation / Q000187:drug effects; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009705:Nucleosides; D012276:Ricin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D006146:Guanidines; D009363:Neoplasm Proteins; D009705:Nucleosides; D005672:Fusidic Acid; C004500:blasticidin S; D012276:Ricin; D003513:Cycloheximide; D001215:Asparaginase