Vasili Hauryliuk (MIMS) and Gemma Atkinson (UCMR) lead milestone paper in PNAS on new kind of regulatory toxin-antitoxin system
Bacteria use small molecules to slam the brakes on their own growth
An international research team under the lead of scientists at Molecular Infection Medicine Sweden (MIMS) and the Umeå Center for Microbial Research (UCMR) have uncovered a new kind of regulatory system of toxin and antitoxin proteins in bacteria that could be a defense system against viral attack. The bioinformatic identification of the proteins and their experimental validation are now published in the high impact journal Proceedings of the National Academy of Sciences of the US (PNAS, 28 April 2020, entitled "A widespread toxin-antitoxin system exploiting growth control via alarmone signaling").
When bacteria get stressed e.g. through antibiotic treatment or the lack of nutrients, they slow down their growth mechanism by small signaling molecules called Alarmones. The Atkinson and Hauryliuk labs at Umeå University have worked on the proteins that make and degrade alarmones for over a decade. They previously revealed the ubiquitous presence of small proteins that make alarmones, called small alarmone synthetases or SASs, encoded in bacterial genomes.
It was an unanswered question why bacteria carry SAS proteins in addition to their standard tool-set for alarmone synthesis and degradation. Now, Gemma C. Atkinson, Vasili Hauryliuk and their colleagues found an explanation. They showed that some SASs are components of so-called toxin-antitoxin (TA) systems.