Low productivity of ribonucleotide reductase in Saccharomyces cerevisiae increases sensitivity to stannous chloride
Genet. mol. res. (Online)
; Genet. mol. res. (Online);7(1): 1-6, Jan. 2008. ilus
Article
in En
| LILACS
| ID: lil-553764
Responsible library:
BR26.1
ABSTRACT
Ribonucleotide reductase (RNR) of the yeast Saccharomyces cerevisiae is a tetrameric protein complex, consisting of two large and two small subunits. The small subunits Y2 and Y4 form a heterodimer and are encoded by yeast genes RNR2 and RNR4, respectively. Loss of Y4 in yeast mutant rnr4delta can be compensated for by up-regulated expression of Y2, and the formation of a small subunit Y2Y2 homodimer that allows for a partially functional RNR. However, rnr4delta mutants exhibit slower growth than wild-type (WT) cells and are sensitive to many mutagens, amongst them UVC and photo-activated mono- and bi-functional psoralens. Cells of the haploid rnr4delta mutant also show a 3- to 4-fold higher sensitivity to the oxidative stress-inducing chemical stannous chloride than those of the isogenic WT. Both strains acquired increased resistance to SnCl2 with age of culture, i.e., 24-h cultures were more sensitive than cells grown for 2, 3, 4, and 5 days in liquid culture. However, the sensitivity factor of three to four (WT/mutant) did not change significantly. Cultures of the rnr4delta mutant in stationary phase of growth always showed higher frequency of budding cells (budding index around 0.5) than those of the corresponding WT (budding index <0.1), pointing to a delay of mitosis/cytokinesis.
Key words
Full text:
1
Collection:
01-internacional
Database:
LILACS
Main subject:
Ribonucleotide Reductases
/
Saccharomyces cerevisiae
/
Tin Compounds
/
Genes, Fungal
/
Mutagens
Type of study:
Diagnostic_studies
Language:
En
Journal:
Genet. mol. res. (Online)
Journal subject:
BIOLOGIA MOLECULAR
/
GENETICA
Year:
2008
Document type:
Article
Affiliation country:
Brazil
Country of publication:
Brazil