Previous Article | Next Article ![]()
Journal of Bacteriology, September 2000, p. 4970-4978, Vol. 182, No. 17
Department of Molecular Genetics and
Microbiology, University of Florida College of Medicine,
Gainesville, Florida 32610-0266
Received 9 May 2000/Accepted 30 May 2000
The phenotype of an organism is the manifestation of its expressed
genome. The gcr1 mutant of yeast grows at near wild-type rates on nonfermentable carbon sources but exhibits a severe growth defect when grown in the presence of glucose, even when nonfermentable carbon sources are available. Using DNA microarrays, the genomic expression patterns of wild-type and gcr1 mutant yeast
growing on various media, with and without glucose, were compared. A
total of 53 open reading frames (ORFs) were identified as
GCR1 dependent based on the criterion that their expression
was reduced twofold or greater in mutant versus wild-type cultures
grown in permissive medium consisting of YP supplemented with glycerol
and lactate. The GCR1-dependent genes, so defined, fell
into three classes: (i) glycolytic enzyme genes, (ii) ORFs carried by
Ty elements, and (iii) genes not previously known to be
GCR1 dependent. In wild-type cultures,
GCR1-dependent genes accounted for 27% of the total
hybridization signal, whereas in mutant cultures, they accounted for
6% of the total. Glucose addition to the growth medium resulted in a
reprogramming of gene expression in both wild-type and mutant yeasts.
In both strains, glycolytic enzyme gene expression was induced by the
addition of glucose, although the expression of these genes was still
impaired in the mutant compared to the wild type. By contrast, glucose
resulted in a strong induction of Ty-borne genes in the mutant
background but did not greatly affect their already high expression in
the wild-type background. Both strains responded to glucose by
repressing the expression of genes involved in respiration and the
metabolism of alternative carbon sources. Thus, the severe growth
inhibition observed in gcr1 mutants in the presence of
glucose is the result of normal signal transduction pathways and
glucose repression mechanisms operating without sufficient glycolytic
enzyme gene expression to support growth via glycolysis alone.
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Understanding the Growth Phenotype of the Yeast
gcr1 Mutant in Terms of Global Genomic Expression
Patterns
*
Corresponding author. Mailing address: Department of
Molecular Genetics and Microbiology, Box 100266, University of Florida, Gainesville, FL 32610-0266. Phone: (352) 392-0680. Fax: (352) 392-3133. E-mail: hvbaker{at}ufl.edu.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |