SNG1 — a new gene involved in nitrosoguanidine resistance in Saccharomyces cerevisiae

• Published in: Mutation research Vol. 346; no. 4; pp. 207 - 214
• Main Authors: Grey, Martin, Pich, Claus T., Haase, Eckard, Brendel, Martin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-1995; Elsevier
• Subjects: Alkylation damage; Amino Acid Sequence; Biological and medical sciences; Classical genetics, quantitative genetics, hybrids; Cloning, Molecular; DNA repair; DNA Repair - genetics; DNA-Binding Proteins - genetics; Drug Resistance, Microbial - genetics; Epistasis, Genetic; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Genes, Fungal - genetics; Genetics of eukaryotes. Biological and molecular evolution; Glutathione; Glutathione - analysis; Membrane Proteins - genetics; Methylnitronitrosoguanidine - pharmacology; Molecular Sequence Data; Mutagenesis, Insertional; Mutagens - pharmacology; N-Methyl- N′-nitro- N-nitrosoguanidine; Pteridophyta, spermatophyta; Restriction Mapping; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; Sequence Analysis, DNA; Transcription Factors - genetics; Vegetals; Yeast; Alkylation damage; Yeast; N-Methyl- N′-nitro- N-nitrosoguanidine; DNA repair; Glutathione; Membrane protein; Nucleotide sequence; Gene overexpression; Homology; Metabolism; Fungi; Resistance; Alkylating agent; Gene; Chromosome DNA; Ascomycetes; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0165-7992; 0027-5107
• DOI: 10.1016/0165-7992(95)90037-3

We have molecularly characterized the
SNG1 gene that confers hyper-resistance to the mutagen
N-methyl-
N′-nitro-
N-nitrosoguanidine (MNNG) in
Saccharomyces cerevisiae when overexpressed on a multi-copy plasmid. This hyper-resistance to MNNG is not due to depletion of glutathione pools since multi-copy
SNG1 containing yeast transformants contain at least wild type levels of glutathione; DNA repair seems unaffected in these transformants as the multi-copy
SNG1-mediated MNNG hyper-resistance is also seen in DNA repair mutants belonging to each of the three epistasis groups of yeast repair mutants. It could be shown that
SNG1 is not under control of the
YAP1 encoded transcription activator that controls expression of at least two genes involved in MNNG metabolism in yeast,
sng1 null mutants are viable but exhibit only slight sensitivity to MNNG, indicating that
SNG1 does not encode a protein involved in a major detoxification step of this mutagen. Sequencing of the HYR-mediating passenger DNA revealed that
SNG1 encodes a 547 aa polypeptide containing seven transmembrane-spanning regions that may be membrane-bound. Comparison of the DNA sequence with established gene databanks revealed that
SNG1 is a novel yeast gene.