Lightnews — Scholar-powered news

Martin Loose

@nartimsoole.bsky.social

740 followers 330 following 22 posts

Interested in protein self-organization. We rebuild the bacterial cell division machinery and small GTPase networks in vitro. https://looselab.ist.ac.at

looselab.ist.ac.at

Posts Media Videos Starter Packs

Pinned

Martin Loose @nartimsoole.bsky.social · Jul 2

One of the most exciting discoveries from our lab so far is now online as a preprint!

Read a story on how the ParMR and Min systems started to collaborate to create the CorMR cytoskeleton, which now controls cell shape in multicellular cyanobacteria:
www.biorxiv.org/content/10.1...

Evolutionary repurposing of a DNA segregation machinery into a cytoskeletal system controlling cyanobacterial cell shape

Bacteria, despite their diversity, use conserved cytoskeletal systems for their intracellular organization. In unicellular bacteria, the ParMRC DNA partitioning apparatus is well known for forming act...

www.biorxiv.org

2 36 83

Reposted by Martin Loose

Stephan Wilmes @stephanwilmes.bsky.social · Sep 2

Thrilled to share our newest publication in Science Advances!
We uncovered how two RabGEF complexes — Mon1-Ccz1 and Fuzzy-Inturned — adapt to regulate distinct Rab GTPases despite their structurally conserved catalytic core.
www.science.org/doi/full/10....

Mechanistic adaptation of the metazoan RabGEFs Mon1-Ccz1 and Fuzzy-Inturned

The molecular comparison of related RabGEFs reveals adaptation mechanisms of a functional module for specific cellular tasks.

www.science.org

2 4 7

Martin Loose @nartimsoole.bsky.social · Sep 1

*salary is € 1,523* gross/month!

Martin Loose @nartimsoole.bsky.social · Sep 1

We are looking for a Master’s student to join a project on in vitro reconstitution of signaling networks in pathogen–host interactions: combine protein biochemistry, fluorescence microscopy & image analysis. Deadline: September 15.
Find out more and apply here: ist.ac.at/en/job/maste...

Master Thesis Position – Loose Research Group

Our Group The Loose lab at the Institute of Science and Technology Austria (ISTA) is looking for a highly motivated Master student to join our research on the in vitro reconstitution of signaling n...

ist.ac.at

1 6 12

Reposted by Martin Loose

Florian Schur @schurlab.bsky.social · Jul 7

We're hiring a postdoc!
Join our ActinID project to explore an uncharacterized actin-binding protein.

- Background in cell and/or structural biology?
- Eager to bridge both fields?

Get in touch if you're curious or have questions!
#cellbiology #cryoEM #cryoET #actin

ista.ac.at/en/job/postd...

Postdoc Research Group Schur

The Schur lab at the Institute of Science and Technology Austria (ISTA) has an open postdoc position for a highly motivated candidate to be part of our ERC-funded project ActinID. Our Group ...

ista.ac.at

1 11 19

Martin Loose @nartimsoole.bsky.social · Jul 2

Thank you, Thibaut!

Martin Loose @nartimsoole.bsky.social · Jul 2

We’re excited to share this story and would love your feedback!

Martin Loose @nartimsoole.bsky.social · Jul 2

The discovery of dynamic instability in a non-polar filament also raises key mechanistic questions: how are such filament dynamics generated, and how do these polymers shape cells?

1 2

Martin Loose @nartimsoole.bsky.social · Jul 2

These findings challenge the idea that ParMR systems are limited to plasmid segregation. Their plasticity may have enabled other functional innovations across evolution.

1 1

Martin Loose @nartimsoole.bsky.social · Jul 2

and another surprising discovery was that the cell division inhibitor MinC has acquired a second role in these Cyanobacteria: MinC evolved to now also disassemble CorM filaments, a striking case of functional expansion!

1 1

Martin Loose @nartimsoole.bsky.social · Jul 2

Benjamin was also able to acquire fantastic live cell movies of CorM filament dynamics:

1 1 14

Martin Loose @nartimsoole.bsky.social · Jul 2

In vitro reconstitution & cryo-EM show CorM forms dynamically instable, non-polar filaments—an architecture distinct from all known actin- or tubulin-based systems!

1 1

Martin Loose @nartimsoole.bsky.social · Jul 2

We built the first comprehensive phylogeny of ParMR systems, uncovering transitions from plasmids to chromosomes and unexpected functional diversity across the tree of life.

1 1

Martin Loose @nartimsoole.bsky.social · Jul 2

By combining structural, evolutionary, in vitro reconstitution and cell biology approaches we uncovered a new cytoskeletal system - called CorMR - that evolved from a ParMR system.

1 1

Martin Loose @nartimsoole.bsky.social · Jul 2

This project was initiated and led by fantastic postdoc Benjamin Springstein, @huepfkiesel.bsky.social in a collaboration with the labs of Florian Schur (cryo-EM)
@schurlab.bsky.social at ‪@istaresearch.bsky.social‬ and Daniela Megrian (phylogenetics) from ‪@ipmontevideo.bsky.social‬

1 2

Martin Loose @nartimsoole.bsky.social · Jul 2

Evolutionary repurposing of a DNA segregation machinery into a cytoskeletal system controlling cyanobacterial cell shape

www.biorxiv.org

2 36 83

Martin Loose @nartimsoole.bsky.social · Apr 10

Looking for a student or postdoc!

Want to combine evolutionary analysis + structural modeling with in vitro biochemistry & fluorescence microscopy?
Help us uncover new protein-protein interactions — from in silico to in vitro.

Join us at @istaresearch.bsky.social 👉 looselab.org
🧬💡🔬🎡

looselab.org

18 20

Martin Loose @nartimsoole.bsky.social · Apr 4

Very cool findings from Paula, Andrea et al.! Excited that my student Roman could contribute! See Andrea’s thread below for more details:

Andrea Vettiger @avettiger.bsky.social · Apr 3

It has been coming a long way... happy to share our latest work with you: www.biorxiv.org/content/10.1...
Here, we show the importance of septal fortification by the Class A Penicillin Binding Protein, PBP1b, in E. coli and provide a molecular mechanism for this function. (1/12).

The aPBP-type cell wall synthase PBP1b plays a specialized role in fortifying the Escherichia coli division site against osmotic rupture

A multi-protein system called the divisome promotes bacterial division. This apparatus synthesizes the peptidoglycan (PG) cell wall layer that forms the daughter cell poles and protects them from osmo...

www.biorxiv.org

Reposted by Martin Loose

Paula Navarro @navarropaula.bsky.social · Apr 3

🚨👉 Please check our recent work on bacterial cell division. In situ Cryo-ET reveals the cellular function of the penicillin binding protein 1b supported by AFM, live-cell imaging, in silico AlphaFold proteome screen and TIRFM. Hope you enjoy the read! #teamtomo #cryo-ET ❄️🔬🐎 big thanks to the team!

bioRxivpreprint @biorxivpreprint.bsky.social · Apr 3

The aPBP-type cell wall synthase PBP1b plays a specialized role in fortifying the Escherichia coli division site against osmotic rupture https://www.biorxiv.org/content/10.1101/2025.04.02.646830v1

23 56

Martin Loose @nartimsoole.bsky.social · Mar 31

👉🏻https://ist.ac.at/en/education/postdocs/

Reposted by Martin Loose

STCmicrobeblog @stcmicrobeblog.bsky.social · Mar 23

who doesn't enjoy some beautiful FtsZ rings on a sunday evening? these from 𝘚𝘵𝘢𝘱𝘩𝘺𝘭𝘰𝘤𝘰𝘤𝘤𝘶𝘴 𝘢𝘶𝘳𝘦𝘶𝘴, from all angles, by the @jwveening.bsky.social, posted earlier on 𝕏, on may 6, 2021

Movie S2 from journals.plos.org/plospathogen...
#MicroSky

1 26 99

Martin Loose @nartimsoole.bsky.social · Mar 18

Looking forward having you here!

1 1

Martin Loose @nartimsoole.bsky.social · Dec 20

ISTA has a beautiful campus close to Vienna: maps.app.goo.gl/T8KX1YjQiVYB...

With lots of great and diverse science: www.ista.ac.at/en/research/

Research

Research Institute of Science and Technology Austria (ISTA) is a cross-disciplinary research institution that combines basic science research with graduate education. Our scientists perform theore...

www.ista.ac.at

Martin Loose @nartimsoole.bsky.social · Dec 20

Excited about protein biochemistry, fluorescence microscopy, and image analysis? Curious how proteins drive bacterial division or define organelle identity? Join us at ISTA! Apply to the PhD program by Jan 8th: gradschool.ist.ac.at

gradschool.ist.ac.at

1 8 13

Martin Loose @nartimsoole.bsky.social · Dec 18

Thanks! Septins are an interesting case! Amphiphaseek for example doesn't detect the C-terminal amphipathic helix of yeast Cdc12, although it usually performs very well!

Martin Loose @nartimsoole.bsky.social · Dec 18

demonstrated!