Glycolytic gene expression in Saccharomyces cerevisiae: nucleotide sequence of GCR1, null mutants, and evidence for expression.

Abstract

In Saccharomyces cerevisiae, the gcr mutation is known to have a profound effect on the levels of most glycolytic enzymes, reducing them to 5% of normal or less in growth on noncarbohydrates. Here I report the preparation of chromosomal gcr insertion and deletion mutations. The null mutations were recessive, were not lethal, and caused a pattern of glycolytic enzyme deficiency similar to that seen earlier for the gcr1-1 allele, including the partial inducibility by glucose of the residual enzyme activities. DNA sequence analysis showed that GCR1 encoded a protein of molecular weight 94,414, with a very low codon bias index, characteristic of several S. cerevisiae regulatory genes; adjacent 5' and 3' sequences contained elements suggesting that it was transcribed, polyadenylated, and translated. RNA gel transfer hybridization experiments with purified polyadenylated RNA and a probe complementary to the 5' portion of the open reading frame showed that Ger was expressed as a polyadenylated transcript. Together with previous work, the present results suggest that the Gcr product may be a transcriptional factor necessary specifically for the high-level transcription of a limited set of genes whose products, the enzymes of glycolysis, constitute a substantial fraction of cell proteins and are responsible for the primary metabolic flux in many cells.