Bacterial toxin-antitoxin systems:yin and yang of death and persistence

Abstract:

Toxin-Antitoxin Systems (TA) are prevalent in mobile genetic elements and chromosomes of prokaryotes. They have been classified into six different types based on the nature of the antitoxin and the way of activating the toxin. TA systems have been shown to play roles in the formation of dormancy and persister cell formation, and they have also been shown to participate in other important physiological processes such as programmed cell death, biofilm formation and general stresses responses. In the last three decades, the cellular targets and the regulation of TA systems have been revealed in both commensal and pathogenic bacteria; however, they have been largely unexplored in environmental microbes. In addition, most studies have focused on Type Ⅱ TA systems, and more efforts need to be devoted to other types of TA systems. This review focused on recent discoveries of novel TA systems, their novel targets, the interaction among different TA systems, and the regulatory roles of the antitoxins. Moreover, we discussed the potential future directions for research in the TA field as well as their applications in biotechnology and in medicine.