毒素-抗毒素系统在应激环境下的生物学作用的研究进展

Progress of the Biological Roles of Toxin-Antitoxin System in the Stress Response

毒素-抗毒素系统(toxin-antitoxin system,TAS)广泛存在于细菌染色体及质粒上,是细菌中含量丰富的小型遗传元件。TAS通常由两个紧密相连的基因组成,分别编码毒素(toxin)和抗毒素(antitoxin),稳定的毒素能够损伤宿主细胞,不稳定的抗毒素能够保护宿主细胞免于毒素的损伤作用。依据其性质和作用方式,目前已经发现三种型别的TAS。TAS具有多种生物学作用,如诱导程序性细胞死亡(programmed cell death,PCD),应激条件下介导持留菌形成(persistence),稳定基因大片段等。本文就近几年TAS在应激条件下的生物学作用的研究进展做一综述。

Toxin-antitoxin （TA） systems are small genetic modules that are widespread and abundant in bacterial chromosomes and plasmids. TA systems are usually composed of two closely linked genes that encode a stable toxin and a labile antitoxin, respectively. The toxin can harm the host cell, while the cognate antitoxin protects the host cell from the toxin＇s damage. So far, three types of TA sys- tem have been described based on their nature and mode of action. Several biological functions of the TA systems have been proposed, such as inducing programmed cell death （PCD）, mediating arrest under stress conditions （persistence）, promoting stability of large genomic fragments, etc. This review summarizes recent findings on the biological roles of TA systems under stress conditions.