From poison to possibility: characterising novel eukaryotic toxin-antitoxin systems for biotechnological applications

<p dir="ltr">Many microorganisms have evolved unique mechanisms to outcompete other species cohabitating their niche environment. Examples include the production of toxins, which are often lethal to competitors. In many instances, the host cell requires expression of a cognate antitoxin, forming a unique toxin-antitoxin (TA) pair. TA systems have garnered significant interest in the field of biotechnology, with many potential applications as a synthetic biology tool. Although bacterial toxin-antitoxin systems have been studied for decades, the potential of eukaryotic systems have yet to be fully explored. In this work, we developed a novel system to properly characterize these TA systems. This was achieved by constructing a modular system of toxins and antitoxins with promoters and terminators, creating a library from which we can mix and match various TA combinations under assorted expression levels. This work has confirmed the activity of 9 different toxins and demonstrated resuscitation from 7 of their cognate antitoxins. The novel promoter <i>DDI2 </i>was also characterised, and found to have strong initial induction, but rapidly loses strength afterwards. Future plans include identifying cross-talk between non-cognate TA pairs. This knowledge will form the foundation from which new synthetic biology tools can be developed.</p>