DIPHTHERIA TOXIN-RESISTANT MUTANTS OF SACCHAROMYCES-CEREVISIAE
DIPHTHERIA TOXIN-RESISTANT MUTANTS OF SACCHAROMYCES-CEREVISIAE
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DOI：
10.1128/mcb.5.12.3357
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发表时间：
1985-01-01
影响因子：
5.3
通讯作者：
LIVINGSTON, DM
中科院分区：
文献类型：
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作者：
CHEN, JYC;BODLEY, JW;LIVINGSTON, DM
我们根据白喉毒素杀死酿酒酵母原生质球的观察结果开发了一种选择程序（Murakami 等，Mol. Cell. Biol. 2:588-592, 1982）；这一过程产生了对毒素体外作用具有抵抗力的突变体。诱变的原生质球。在白喉毒素存在下转化酿酒酵母，并在体外筛选转化的存活者的毒素抗性延伸因子2。通过该程序获得了包含5个互补组的31个单倍体ADP核糖基化阴性突变体。突变体生长正常并且长期储存稳定。通过野生型敏感细胞与突变体交配产生的杂合二倍体表明，在每种情况下，抗性表型都是敏感表型的隐性。这些二倍体的孢子形成产生四分体，其中抗性表型分离为单一孟德尔特征。根据这些观察结果，我们得出结论，这些突变体在负责延伸因子 2 翻译后修饰的酶促步骤中存在缺陷，而延伸因子 2 是白喉毒素识别所必需的。
We developed a selection procedure based on the observation that diphtheria toxin kills spheroplasts ofSaccharomyces 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 mutagenizedS. cerevisiaewere 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.