Duperray Maëlle, François Jean-Marie, Capp Jean-Pascal
Toulouse Biotechnology Institute, INSA/University of Toulouse, CNRS, INRAE, Toulouse 31077, France.
Toulouse White Biotechnology, UMS INRAE 1337, UMS CNRS 3582, INSA, Toulouse 31077, France.
FEMS Yeast Res. 2023 Jan 4;23. doi: 10.1093/femsyr/foad009.
The bacterial toxin-antitoxin systems are each composed of a toxin, which severely inhibits bacterial cells growth, and a specific neutralizing antitoxin. Some toxin-antitoxin systems are functional when expressed in the yeast Saccharomyces cerevisiae. For instance, the expression of the relE toxin gene leads to a strong growth defect in yeast, whereas the expression of the relB antitoxin gene restores growth. Nevertheless, there is no available data regarding the required expression levels of each component of the relBE system leading to these growth phenotypes, neither their effects on cell viability. Here we used a double inducible plasmid-based system to independently modulate the relative amounts of relB and relE, and performed growth and gene expression analyses. These results allow us to correlate growth phenotypes to the expression levels of the toxin and the antitoxin, and to determine the levels necessary to observe either a strong growth inhibition or a normal growth. We also showed that the relE expression produces cell cycle progression defect without affecting cell viability. These results provide a detailed characterization of the functioning of the relBE system in S. cerevisiae, and open applicative perspectives of yeast growth control by bacterial toxin-antitoxin systems.
细菌毒素-抗毒素系统均由一种严重抑制细菌细胞生长的毒素和一种特异性中和抗毒素组成。一些毒素-抗毒素系统在酿酒酵母中表达时具有功能。例如，relE毒素基因的表达会导致酵母出现严重的生长缺陷，而relB抗毒素基因的表达则能恢复生长。然而，关于relBE系统各组分导致这些生长表型所需的表达水平，以及它们对细胞活力的影响，目前尚无可用数据。在此，我们使用了基于双诱导质粒的系统来独立调节relB和relE的相对量，并进行了生长和基因表达分析。这些结果使我们能够将生长表型与毒素和抗毒素的表达水平相关联，并确定观察到强烈生长抑制或正常生长所需的水平。我们还表明，relE的表达会导致细胞周期进程缺陷，但不影响细胞活力。这些结果详细描述了relBE系统在酿酒酵母中的功能，并为利用细菌毒素-抗毒素系统控制酵母生长开辟了应用前景。
