title: Pleiotropic glucose repression-resistant mutation in Saccharomyces carlesbergensis.
abstract: We describe the characterization of a mutation of the locus GLR1. This mutation allowed for (i) the glucose repression-insensitive synthesis ot the enzymes maltase, galactokinase, alpha-galactosidase, reduced nicotinamide adenine dinucleotide-cytochrome c reductase, and cytochrome c oxidase and (ii) growth on maltose in the presence of the gratuitous glucose repressor D-glucosamine. The glucosamine resistance cosegregated with the glucose-insensitive synthesis of the enzymes listed above. In addition, crosses between the glucosamine-resistant mutant and isogenic sensitive strains gave only tetrads containing two resistant and two sensitive spores. Thus, a single pleiotropic mutation is responsible for both phenotypes. We call the locus GLR1, for glucose regulation, and the glucose repression-insensitive mutation glr1-1.
mesh_terms: D002244:Carbon / Q000378:metabolism; D004352:Drug Resistance, Microbial; D004790:Enzyme Induction / Q000187:drug effects; D004794:Enzyme Repression / Q000187:drug effects*; D005944:Glucosamine / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology*; D009154:Mutation; D012440:Saccharomyces / Q000235:genetics*
chemical_list: D002244:Carbon; D005947:Glucose; D005944:Glucosamine