Wejksnora P J, Warner J R
Eur J Biochem. 1982 Nov;128(1):239-42. doi: 10.1111/j.1432-1033.1982.tb06957.x.
Emetine is an antibiotic which inhibits the activity of the 40-S subunits of eukaryotic ribosomes. A number of emetine-resistant mutants of Chinese hamster cells have been isolated. We have studied the ribosomes isolated from strains carrying either of two alleles of an emetine resistance locus, one of which leads to an alteration in the electrophoretic mobility of ribosomal protein S14. Both mutations lead to a loss of specific proteins, including S14, from 40-S subunits isolated in 0.5 M KCl, an effect which is enhanced at elevated temperature. 40-S subunits from wild-type cells retain their proteins even at substantially higher concentrations of KCl. Interestingly, the two mutant alleles lead to the loss of slightly different sets of proteins from the 40-S subunits. These results suggest that protein S14 plays an important role in the structure of the ribosome and raise the possibility that resistance to emetine is accomplished through an alteration in a complex emetine-binding site rather than in a single emetine-binding protein.
吐根碱是一种抗生素，它能抑制真核生物核糖体40-S亚基的活性。已经分离出了许多对吐根碱有抗性的中国仓鼠细胞突变体。我们研究了从携带吐根碱抗性位点两个等位基因之一的菌株中分离出的核糖体，其中一个等位基因会导致核糖体蛋白S14的电泳迁移率发生改变。这两种突变都会导致从在0.5M KCl中分离出的40-S亚基中丢失特定蛋白质，包括S14，在升高温度时这种效应会增强。来自野生型细胞的40-S亚基即使在KCl浓度高得多的情况下也能保留其蛋白质。有趣的是，这两个突变等位基因导致40-S亚基中丢失的蛋白质组略有不同。这些结果表明蛋白质S14在核糖体结构中起重要作用，并增加了对吐根碱的抗性是通过复杂的吐根碱结合位点的改变而非单个吐根碱结合蛋白的改变来实现的可能性。
