Diphtheria toxin-resistant mutants of Saccharomyces cerevisiae.

AUTOR(ES)

Chen, J Y

RESUMO

We developed a selection procedure based on the observation that diphtheria toxin kills spheroplasts of Saccharomyces cerevisiae (Murakami et al., Mol. Cell. Biol. 2:588-592, 1982); this procedure yielded mutants resistant to the in vitro action of the toxin. Spheroplasts of mutagenized S. cerevisiae were transformed in the presence of diphtheria toxin, and the transformed survivors were screened in vitro for toxin-resistant elongation factor 2. Thirty-one haploid ADP ribosylation-negative mutants comprising five complementation groups were obtained by this procedure. The mutants grew normally and were stable to prolonged storage. Heterozygous diploids produced by mating wild-type sensitive cells with the mutants revealed that in each case the resistant phenotype was recessive to the sensitive phenotype. Sporulation of these diploids yielded tetrads in which the resistant phenotype segregated as a single Mendelian character. From these observations, we concluded that these mutants are defective in the enzymatic steps responsible for the posttranslational modification of elongation factor 2 which is necessary for recognition by diphtheria toxin.

Documentos Relacionados

• Expression of diphtheria toxin fragment A and hormone-toxin fusion proteins in toxin-resistant yeast mutants.
• Ultraviolet light induction of diphtheria toxin-resistant mutants of normal and xeroderma pigmentosum human fibroblasts.
• Binding and uptake of diphtheria toxin by toxin-resistant Chinese hamster ovary and mouse cells.
• Interaction of diphtheria toxin and its active subunit, fragment A, with toxin-sensitive and toxin-resistant cells.
• Isolation of diphtheria toxin-sensitive mouse cells from a toxin-resistant population transfected with monkey DNA.