Calum H. G. Johnston
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chgjohnston.bsky.social
Calum H. G. Johnston
@chgjohnston.bsky.social
CNRS researcher in the pneumococcal competence and transformation team in Toulouse.

Using molecular genetics and cell biology to study pneumococcal competence and transformation.
Reposted by Calum H. G. Johnston
Come and work with me and @ariannebabina.bsky.social on #Streptomyces evolution and antibiotic production

Origins of a tangled bank: Adaptation and evolution in antibiotic-producing Streptomyces

www.gla.ac.uk/postgraduate...

please repost
University of Glasgow - Postgraduate study - Centres for Doctoral Training - NorthWest Biosciences - Our Projects - Underpinning Bioscience - Paul A Hoskisson
www.gla.ac.uk
September 30, 2025 at 11:02 AM
New paper from our lab up on Biorxiv, showing how a toxin targets replication to induce competence. 👇
A toxin/antitoxin system targeting the replication sliding-clamp induces competence in Streptococcus pneumoniae. https://www.biorxiv.org/content/10.1101/2025.09.02.673660v1
September 3, 2025 at 11:12 AM
Reposted by Calum H. G. Johnston
Offre de thèse disponible dans notre équipe au @mmsb-lyon.bsky.social
Si vous êtes étudiant(e) en Master 2 et intéressé(e) par la génétique bactérienne, microscopie à épifluorescence et biochimie, contactez-nous et postulez à l'offre!
Dossier pour le 13/06
Concours école doctorale E2M2: 8 et 9/07.
Elucider le rôle des messagers secondaires (p)ppGpp et c-di-GMP dans la coordination des réponses bactériennes au stress et à l'adhésion à une surface // Decoding the role of intracellular messengers ...
Comprendre comment les bactéries modulent leur croissance face à des changements environnementaux est essentiel pour développer de nouvelles stratégies de lutte contre les infections. Dans notre labo...
www.abg.asso.fr
May 23, 2025 at 1:35 PM
For those who are interested in all things 'transformation', here is a link to registration for the 6th edition of the Zoom on Griffith's Legacy, the 4th and 5th June 2025.

griffiths2025.sciencesconf.org

It has been fun co-organising this with Luisa Hiller. We hope to see you there!
6th Zoom on Griffiths Legacy - 2025 - Sciencesconf.org
griffiths2025.sciencesconf.org
May 13, 2025 at 11:34 AM
Pleased to share a new preprint - a great collaboration with @jessicaandreani.bsky.social and the Guerois lab at I2BC, and the Radicella lab at the CEA. Using stuctural modelling, we reveal & validate a 3 protein complex involved in DNA import during transformation.

www.biorxiv.org/content/10.1...
A tripartite protein complex promotes DNA transport during natural transformation in firmicutes.
Natural genetic transformation is a conserved mechanism of bacterial horizontal gene transfer, which is directed entirely by the recipient cell and facilitates the acquisition of new genetic traits su...
www.biorxiv.org
May 12, 2025 at 6:14 AM
Reposted by Calum H. G. Johnston
Let's start the Bsky adventure with a job post. Still about two weeks to apply to this postdoc position on "Molecular and Structural Biology of Membrane Biogenesis" in the labs @raffaeleieva.bsky.social ky.social and @fronzeslab.bsky.social slab.bsky.social in beautiful south-west of France!
November 29, 2024 at 10:44 PM
Really proud of our new paper, my first as last author. We explored the importance of homologous recombination genes in transformation and genotoxic stress tolerance during competence. Give it a read/like! 🙂

journals.asm.org/doi/10.1128/...
Competence induction of homologous recombination genes protects pneumococcal cells from genotoxic stress | mBio
Homologous recombination (HR) is a mechanism of DNA strand exchange important for both the maintenance and plasticity of bacterial genomes. Bacterial HR is driven by the recombinase RecA along with ma...
journals.asm.org
November 29, 2024 at 3:32 PM