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.
Using molecular genetics and cell biology to study pneumococcal competence and transformation.
Reposted by Calum H. G. Johnston
Delighted to share a new paper from our lab, a study led by Mathieu Bergé looking at how an endogenous toxin targets replication to induce competence in the pneumococcus. dx.plos.org/10.1371/jour...
A toxin/antitoxin system targeting the replication sliding-clamp induces competence in Streptococcus pneumoniae
Author summary The environment in which bacteria live puts them under a great deal of stress, forcing them to adapt constantly, either temporarily or permanently. Streptococcus pneumoniae, a pathogeni...
dx.plos.org
January 8, 2026 at 9:03 AM
Delighted to share a new paper from our lab, a study led by Mathieu Bergé looking at how an endogenous toxin targets replication to induce competence in the pneumococcus. dx.plos.org/10.1371/jour...
Reposted by Calum H. G. Johnston
A cool genetic system to study site-pecific replication fork collapse and repair from the brilliant @winterhalterlab.bsky.social
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Rescuing the bacterial replisome at a nick requires recombinational repair and helicase reloading - Nature Communications
DNA damage can lead to cell death. Here, the authors show that a simple cut on either strand of DNA can inactivate bacterial chromosome replication. Surprisingly, only a core set of recombination prot...
www.nature.com
December 30, 2025 at 10:49 AM
A cool genetic system to study site-pecific replication fork collapse and repair from the brilliant @winterhalterlab.bsky.social
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Calum H. G. Johnston
New pub. from the lab !
We discovered that potato tubers exert intense selective pressure during Dickeya solani infection, driving the rapid emergence of mutations in the sRNA ArcZ. These mutations lead to the appearance of "social cheaters" that sweep through the pop. in as few as 30 generations.
We discovered that potato tubers exert intense selective pressure during Dickeya solani infection, driving the rapid emergence of mutations in the sRNA ArcZ. These mutations lead to the appearance of "social cheaters" that sweep through the pop. in as few as 30 generations.
Host infection selects for sRNA variants that drive bacterial social cheating https://www.biorxiv.org/content/10.64898/2025.12.19.695336v1
December 22, 2025 at 5:24 PM
New pub. from the lab !
We discovered that potato tubers exert intense selective pressure during Dickeya solani infection, driving the rapid emergence of mutations in the sRNA ArcZ. These mutations lead to the appearance of "social cheaters" that sweep through the pop. in as few as 30 generations.
We discovered that potato tubers exert intense selective pressure during Dickeya solani infection, driving the rapid emergence of mutations in the sRNA ArcZ. These mutations lead to the appearance of "social cheaters" that sweep through the pop. in as few as 30 generations.
Reposted by Calum H. G. Johnston
Reposted by Calum H. G. Johnston
Le 1er janvier 2026, le CNRS coupera l’accès au Web of Science, Core Collection et Journal Citation Reports. Une nouvelle étape de sa politique en faveur de la science ouverte pour promouvoir des alternatives ouvertes, transparentes et responsables.
Le CNRS s’émancipe du Web of Science
À partir du 1er janvier 2026, le CNRS coupera l’accès à l’une des plus importantes bases bibliométriques commerciales : le
www.cnrs.fr
December 1, 2025 at 11:02 AM
Le 1er janvier 2026, le CNRS coupera l’accès au Web of Science, Core Collection et Journal Citation Reports. Une nouvelle étape de sa politique en faveur de la science ouverte pour promouvoir des alternatives ouvertes, transparentes et responsables.
Reposted by Calum H. G. Johnston
Cool work from Heath Murray's lab where they use Cas9 nickase to study how ssDNA breaks are repaired in Bacillus subtilis #MicroSky www.nature.com/articles/s41...
Rescuing the bacterial replisome at a nick requires recombinational repair and helicase reloading - Nature Communications
DNA damage can lead to cell death. Here, the authors show that a simple cut on either strand of DNA can inactivate bacterial chromosome replication. Surprisingly, only a core set of recombination prot...
www.nature.com
November 28, 2025 at 2:25 PM
Cool work from Heath Murray's lab where they use Cas9 nickase to study how ssDNA breaks are repaired in Bacillus subtilis #MicroSky www.nature.com/articles/s41...
Reposted by Calum H. G. Johnston
New paper alert 🚨
I am super happy about it, for many reasons!
👥 It was a great collaborative project with Calum @chgjohnston.bsky.social and J. Pablo Radicella, designed a long time ago (in the pre-AlphaFold era - can you imagine?) together with @polardlab.bsky.social and @raphguerois.bsky.social
I am super happy about it, for many reasons!
👥 It was a great collaborative project with Calum @chgjohnston.bsky.social and J. Pablo Radicella, designed a long time ago (in the pre-AlphaFold era - can you imagine?) together with @polardlab.bsky.social and @raphguerois.bsky.social
Pleased to share our recent article in PNAS - a collaboration with @jessicaandreani.bsky.social & Pablo Radicella, with important roles played by many members of each team.
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes | PNAS
Natural genetic transformation is a conserved mechanism of bacterial horizontal gene
transfer, which is directed entirely by the recipient cell and...
www.pnas.org
November 28, 2025 at 9:39 AM
New paper alert 🚨
I am super happy about it, for many reasons!
👥 It was a great collaborative project with Calum @chgjohnston.bsky.social and J. Pablo Radicella, designed a long time ago (in the pre-AlphaFold era - can you imagine?) together with @polardlab.bsky.social and @raphguerois.bsky.social
I am super happy about it, for many reasons!
👥 It was a great collaborative project with Calum @chgjohnston.bsky.social and J. Pablo Radicella, designed a long time ago (in the pre-AlphaFold era - can you imagine?) together with @polardlab.bsky.social and @raphguerois.bsky.social
Pleased to share our recent article in PNAS - a collaboration with @jessicaandreani.bsky.social & Pablo Radicella, with important roles played by many members of each team.
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes | PNAS
Natural genetic transformation is a conserved mechanism of bacterial horizontal gene
transfer, which is directed entirely by the recipient cell and...
www.pnas.org
November 26, 2025 at 7:44 AM
Pleased to share our recent article in PNAS - a collaboration with @jessicaandreani.bsky.social & Pablo Radicella, with important roles played by many members of each team.
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
A tripartite protein complex promotes DNA transport during natural transformation in Firmicutes www.pnas.org/doi/10.1073/...
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
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
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
Origins of a tangled bank: Adaptation and evolution in antibiotic-producing Streptomyces
www.gla.ac.uk/postgraduate...
please repost
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
New paper from our lab up on Biorxiv, showing how a toxin targets replication to induce competence. 👇
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.
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
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.
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.
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!
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
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!
griffiths2025.sciencesconf.org
It has been fun co-organising this with Luisa Hiller. We hope to see you there!
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...
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
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...
www.biorxiv.org/content/10.1...
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
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!
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/...
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
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/...
journals.asm.org/doi/10.1128/...