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"All T6SS-inducing regulators are equal, but some regulators are more equal than others".
Preprint 🚨: We use #Vibrio to show that #T6SS activation by regulator manipulation may result in the expression of different effector repertoires, affecting toxicity 🦠
www.biorxiv.org/content/10.6...
Very cool! Marine bacteria have evolved “hooks” to attach and kill both kin and non-kin in liquid!
It is widely accepted that #T6SS -mediated intoxication occurs only on solid surfaces, where prolonged cell-cell interactions are forced, and not in liquid environments. But is this generalization true? Our new preprint says it isn't. A 🧵 ...
biorxiv.org/content/10.6...
🦠
New lab preprint! Andrew Frando, Bobby Parsek, and Graham Roberts describe how components of the quinolone quorum sensing circuit of P. aeruginosa interact in competition with another Gram-negative bacterium, S. maltophilia -- it's a three-component AND logic gate.
www.biorxiv.org/content/10.6...
Thanks!
Congratulations to the new cohort of 28 EMBO Young Investigators! They are joining an international network of more than 800 life scientists – Welcome!
Read the press release here:
https://www.embo.org/press-releases/twenty-eight-group-leaders-become-embo-young-investigators/
Very cool story! Congrats!
Be our IMB colleague! Join us for cool science!
[open faculty position at the institute of molecular biology, academia sinica in taiwan]
www.nature.com/naturecareer...
Thanks Dor!
Overall, our findings expand our understanding of how bacteria outcompete one another in crowded environments. Check out our story! 💪
Interestingly, we found that the bacteria secreting Cpe1 are protected from self-poisoning by a protein called Cpi1. Cpi1 blocks the toxin using a unique mode. Unlike many other immunity that block the toxin’s active site, Cpi1 inhibits Cpe1 by blocking the substrate-binding site.
Using structural and mass spec approaches, we pinpointed the exact cleavage target sequences of Cpe1: in the short “double-glycine” motifs, specifically LHAGGKF, in GyrB and ParE!
This interbacterial toxin is called Cpe1. It acts like molecular scissors✂️, cutting the ATPase domains of essential topoisomerases, GyrB and ParE, in competing bacteria. Without the critical proteins, the rival cells can't properly copy their genomes, leading to growth stalls.
Link to the story: doi.org/10.1371/jour...
Bacteria are constantly fighting for survival—not just against bacteriophages, but also against each other. In our new study, we uncover an antibacterial protease toxin that bacteria frequently use to disable their rivals.
Excited to learn that our story on characterizing an interbacterial protease toxin is finally out @plosbiology.org
"An interbacterial cysteine protease toxin inhibits cell growth by targeting type II DNA topoisomerases GyrB and ParE". Led by my wonderful team at Academia Sinica!
Always love a good bacterial warfare study:
"Horizontal gene transfer of molecular weapons can reshape bacterial competition"
by @prokaryota.bsky.social, @jdpal.bsky.social, et al. in @plosbiology.org
journals.plos.org/plosbiology/...
OUT NOW: Inducible transposon mutagenesis identifies bacterial fitness determinants during infection in mice
#microsky 🧪
www.nature.com/articles/s41...
n summary, our findings show that while phage resistance helps bacteria avoid viral infection, it can come at the cost of losing the battle against other bacteria in the environment. A double-edged sword! ⚔️🔬
More interestingly, even when Salmonella was treated with an enzyme from phages that degrades LPS, it also became vulnerable to bacterial attacks, demonstrating that phages can indirectly weaken bacteria and affect bacteria-bacteria interaction.
Further experiments revealed that the O-antigen, a part of the LPS structure, is crucial for protecting Salmonella against these bacterial attacks. Without it, they became easy targets.
The reason why Salmonella lose their ability to compete is due to mutations in genes related to their cell membrane, specifically in a structure called LPS (lipopolysaccharide), which normally protects against external stresses. Bacteria with damaged LPS became vulnerable to T6S.
We used Salmonella phage-resistants as the model for the question. Interestingly, while resistant strains grew and competed normally in liquid media, they struggled when grown on solid media with bacteria with the specialized weapon: type VI secretion system (T6SS)
Bacteria can become resistant to phages that infect them, but this resistance might weaken their ability to compete with other bacteria. Here, we start by asking how phage-resistant bacteria perform in competition with other competitor bacteria.
Our Phage infection/T6S story is finally out @embojournal.org! "Surface-mediated bacteriophage defense incurs fitness tradeoffs for interbacterial antagonism" Led by my wonderful team at Academia Sinica!
www.embopress.org/doi/full/10....
A҉L҉T҉R҉U҉I҉S҉T҉I҉C҉ ҉Z҉O҉M҉B҉I҉E҉ ҉B҉A҉C҉T҉E҉R҉I҉A҉🦠🧟
Fascinating Nat Comm paper Martin Cann Lab Durham UK
Dead bacteria encode post-mortem protein catabolism via Lon protease—provides nutrients promoting growth of surviving bacteria
No benefit of Lon to live bacteria to account for this
www.nature.com/articles/s41...
Graphic showing modification of mRNA with ADP-ribose mediated by bacterial enzyme cmdTAC
Check it out! Another novel RNA modification - ADP-ribosylation - that was previously only known on proteins. A cousin to #glycoRNA 👏
www.nature.com/articles/s41...
Discovery of a distinct BAM complex in the Bacteroidetes https://www.biorxiv.org/content/10.1101/2025.01.31.636011v1
A ubiquitin-like protein controls assembly of a bacterial Type VIIb secretion system https://www.biorxiv.org/content/10.1101/2025.01.24.634720v1
Beautiful #symbiosis paper. Symbiosis and horizontal gene transfer promote herbivory in the megadiverse leaf beetles
www.cell.com/current-biol...
What do bacterial cells do when they run out of nutrients? Although most bacterial studies focus on cells in exponentially growing states, in the wild bacteria likely spend most of their time slowly starving to death. 1/n
www.biorxiv.org/content/10.1...
