SCHIZOSACCHAROMYCES-POMBE RDS1, AN ADENINE-REPRESSIBLE GENE REGULATEDBY GLUCOSE, AMMONIUM, PHOSPHATE, CARBON-DIOXIDE AND TEMPERATURE

We report the isolation and characterization of an adenine-repressible gene, rds1, in the fission yeast Schizosacckaromyces pombe. The trans cript of rds1 is greatly increased in abundance when adenine auxotroph ic strains are starved for adenine. rds1 is also derepressed when wild -type cells are starved for glucose, ammonium, or phosphate. In additi on, derepression occurs when wild-type cells are exposed to a carbon d ioxide atmosphere, when they are shifted to higher temperatures or whe n they enter stationary phase. The nucleotide sequence of the rds1 gen e and the corresponding amino acid sequence of its protein share no ob vious homologies with any other known gene or protein and we have not found a phenotype for rds1 disruption mutants. We speculate that expre ssion of the rds1 gene is regulated by one or several components of th e adenine nucleotide pool and that its gene product has a function in stress-related responses of the cell.