Diepold Lab

Secreting bacteria undergo drastic changes.
We found that in Yersinia, T3SS activation triggers rapid, large-scale reorganisation of chromosomal and plasmid DNA. This links secretion to growth inhibition-revealing a new connection between virulence and bacterial cell biology.
doi.org/10.1016/j.ce...

What if even the core of bacterial nanomachines wasn’t static?

We found that the T3SS core protein SctD in Yersinia dynamically exchanges subunits — and this flexibility is essential for proper assembly & function.

🔗 www.nature.com/articles/s41...

@kit.edu @t3sss.bsky.social

Special thanks 🙏 go to first author @ljmihajlovic.bsky.social , as well as Lara Hofacker, Florian Lindner, Priyanikha Jayakumar, and collaborator @diepold-lab.bsky.social !

Yersinia actively downregulates type III secretion and adhesion at higher cell densities Author summary Bacteria can use the type III secretion system (T3SS), a molecular syringe-like device, to manipulate host cells by injecting effector proteins. Yersinia enterocolitica, a pathogenic ba...

T3SS activity comes at a cost—bacteria that use the system pay with reduced growth. We found how Yersinia balance costs and benefits: at higher densities, they actively suppress T3SS activity and adhesion, switching from colonization to replication and dissemination.
doi.org/10.1371/jour...
@kit.edu

We recently described how T3SS effectors reach the injectisome with a shuttle system. But what about their chaperones? With live microscopy, proximity labeling and functional assays, @keithpint.bsky.social showed the Yersinia chaperone SycH already hands over its cargo in the cytosol. bit.ly/47hq6rM

This is the first of three manuscripts we’ve recently had accepted — more to come soon! 🚀
#Microbiology #InfectionBiology #SingleCell

That's how we think Pseudomonas aeruginosa uses the T3SS, H1-T6SS, and flagellum during infection.

Using live-cell microscopy, we uncovered distinct bacterial subpopulations that primarily use certain combinations of these nanomachines:
• some prioritize motility & T3SS
• others shift to T6SS for antagonism
All tuned by the usual suspect: cyclic di-GMP.

Our first accepted manuscript at my new lab (@kitkarlsruhe) is out in Communications Biology! 🎉
We show how Pseudomonas aeruginosa coordinates its virulence systems, T3SS, H1-T6SS, flagellum, at single-cell resolution.
🔗 www.nature.com/articles/s42...
@t3sss.bsky.social @NaturePortfolio.bsky.social

🛠️Toolbox 🛠️ out to modulate gene expression & protein secretion in a predatory bacterium.
📑Preprint from my group below.
Many thanks to L. Mihajlovic @ljmihajlovic.bsky.social, L. Hofacker, F. Lindner, P. Jayakumar & A. Diepold @diepold-lab.bsky.social! #MicroSky #SyntheticBiology #PredatoryBacteria

Activation of the Yersinia type III secretion system induces large-scale chromosomal and virulence plasmid DNA rearrangements The type III secretion system (T3SS) is used by Gram-negative bacteria, including important pathogens, to manipulate eukaryotic target cells by injecting effector proteins. Type III secretion and bact...

New preprint:
Virulence does not come for free - activity of the T3SS stops bacterial growth.
We show that in Y. enterocolitica, activating secretion triggers major DNA rearrangements.
Could this be the key to secretion-associated growth inhibition?
Read more here: www.biorxiv.org/content/10.1...

Hello world, our lab investigates bacterial secretion systems and virulence mechanisms to better understand their role in infection biology, and their application in biotech and healthcare.
Since October 2024, we are the Department of Applied Biology at the KIT
@kitkarlsruhe.bsky.social