title: Increased levels of threonyl-tRNA synthetase in a borrelidin-resistant Chinese hamster ovary cell line.
abstract: The growth of Chinese hamster ovary cells in medium containing reduced concentrations of threonine is inhibited by borrelidin, a macrolide antibiotic. Borrelidin-resistant clones have been isolated after ethyl methanesulfonate mutagenesis. One clone, 1C-1, has a 3-fold increased level of threonyl-tRNA synthetase [L-threonine:tRNAThr ligase (AMP-forming), EC 6.1.1.3] as determined by both activity measurements and antiserum titrations. The levels of four other aminoacyl-tRNA synthetases and of tRNAThr are the same in strain 1C-1 and in the wild-type parent. The phenotype of increased threonyl-tRNA synthetase activity is recessive to wild type in cell hybrids.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004351:Drug Resistance; D005233:Fatty Alcohols / Q000494:pharmacology*; D005786:Gene Expression Regulation; D005808:Genes, Recessive; D006822:Hybrid Cells / Q000201:enzymology; D009154:Mutation; D013914:Threonine-tRNA Ligase / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D005233:Fatty Alcohols; C005066:borrelidin; D000604:Amino Acyl-tRNA Synthetases; D013914:Threonine-tRNA Ligase