Claudia Hemsley
@chemsley.bsky.social
Molecular Biologist | Microbiologist with an interest in gene-regulation and pathogenesis. Currently in Dundee 🏴 Favourite bugs are #Pseudomonas #Coxiella #Burkholderia #UPEC Views are my own.
📢 The preliminary research day programme for the Galleria Mellonella Workshop 2026 is now available! 👉 Registration remains open until the 1st of September and we continue to welcome poster submissions until the 31st of August. 🧑💻Visit www.gmrcuk.org/gmw-2026.html for more info
Effector loss and gain drives host range at a fitness cost In PLoS Pathogens journals.plos.org/plospathogen...
Effector loss and gain drives host range at a fitness cost
Author summary Pathogenic microorganisms emerge and adapt to new niches posing problems for host health, such as when disease outbreaks occur. Microorganisms may quickly adapt by modifying their genom...
journals.plos.org
A novel stress response pathway mediates biofilm architecture in Pseudomonas aeruginosa PLOS Pathogens by Ainelen Piazza et al from Jakob Malone @johninnescentre.bsky.social with @friendlymicrobe.bsky.social journals.plos.org/plospathogen...
A novel stress response pathway mediates biofilm architecture in Pseudomonas aeruginosa
Author summary Biofilm formation by the opportunistic pathogen Pseudomonas aeruginosa represents a major clinical challenge, with biofilms typically associated with chronic infection, increased antibi...
journals.plos.org
journals.asm.org/doi/10.1128/... comprehensive review of bacterial RNA modifications 🦠
Compendium of RNA modifications for bacterial stress adaptation | Microbiology and Molecular Biology Reviews
SUMMARYRNA modifications in the tRNA, rRNA, and mRNA constitute a widespread layer of post-transcriptional gene regulation, commonly known as the epitranscriptome. In bacteria, tRNA and rRNA modifications are well documented and play essential roles in tRNA folding, rRNA maturation, translation, and peptidyl transfer. Although mRNA modifications have been extensively characterized in eukaryotes, their functional implications for mRNA fate in prokaryotes remain uncertain, and their identities and locations are the subject of an emerging field of research. Importantly, RNA modification is a dynamic process, and variation in the presence and abundance of these modifications has significant consequences for bacterial physiology. Here, we discuss current knowledge of modified RNA nucleotides in bacteria, with a particular focus on their roles in bacterial adaptation to environmental stress.
journals.asm.org
RNA-seq tells us how much RNA is present in the cell. But to understand gene regulation, we need to easily measure the synthesis and decay rates driving this abundance. We introduce AIR-seq: analog intrinsic recoding sequencing. (1/6) www.biorxiv.org/content/10.6...
Analog intrinsic recoding measures RNA dynamics without chemical conversion
Steady-state RNA abundance measurements mask the synthesis and decay rates that shape gene expression. Analog intrinsic recoding sequencing (AIR-seq) repurposes the base-pairing properties of N4-hydro...
biorxiv.org
The adaptive landscapes of three global Escherichia coli transcriptional regulators @elife.bsky.social by @cauawest.bsky.social et al elifesciences.org/articles/103...
These microbial clusters can eject “escape pods” to survive. Learn more: https://scim.ag/4gJ8WrE
New in JB: Angeli, Rinaldo et al. (we helped a bit on this study) explore cdG signaling with proteins containing periplasmic signaling domains using P. aeruginosa as a model. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol #MicroSky
New in JB: Wang, Hu et al. show that the CRP-like protein of R. anatipestifer crpR1 can be classified into three subtypes based on the protein length, likely impacting virulence of this organism. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol #MicroSky
Metabolic profiling of S. aureus revealed suppressed central carbon and energy metabolism as a shared resistance mechanism. Notably, supplementation with metabolites like pyruvate, citrate, and fumarate enhanced antibiotic efficacy. #JournalSpectrum: asm.social/2ZV
Studying the regulons of OmrA and OmrB paralogous small RNAs reveals targets involved in central carbon metabolism and lipogenesis 🦠 www.biorxiv.org/content/10.6... 💫 @egmresearch.bsky.social
Studying the regulons of OmrA and OmrB paralogous small RNAs reveals targets involved in central carbon metabolism and lipogenesis
Small regulatory RNAs (sRNAs) are key players in bacterial adaptation to stress. They often occupy central positions in regulatory networks and control the expression of multiple targets. In a strikin...
biorxiv.org
New preprint from our lab Statistical learning of bacterial growth in combinatorially constructed environments, led by brilliant PhD student Andrea Arrabal. www.biorxiv.org/content/10.6... We systematically study nutrient-nutrient interactions in bacterial growth under carbon-limiting conditions.
biorxiv.org
Temporal tuning of switch-like virulence expression resolves environmental uncertainty through phenotypic heterogeneity Salmonellaenterica serovar Typhimurium pathogenicity island 2 @currentbiology.bsky.social by Madison Spratt and Keara Lane www.cell.com/current-biol...
Temporal tuning of switch-like virulence expression resolves environmental uncertainty through phenotypic heterogeneity
Spratt et al. evaluate the transcriptional regulation of Salmonella pathogenicity island 2 (SPI-2) at the single-cell level, revealing temporally tunable phenotypic heterogeneity that allows for proba...
cell.com
New in JB: Bellamoroso, Dandekar et al. show that inactivation of the MexT efflux pump results in the emergence of new quorum sensing variants of P. aeruginosa. This work reveals selection pressures driving QS evolution. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
New in JB: Bendo, Sarkar-Tyson et al. show that the trigger factor mutant of B. pseudomallei is markedly attenuated, reducing adhesion, internalization, cytotoxicity & multiple other phenotypes. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
On the cover: Chutes & Ladders capture microbiome dynamics Bacteria diversify into distinct subpopulations via epigenetic changes. Some are better adapted & “climb ladders,” thriving under stress; others succumb to “chutes” or stressors, e.g. antibiotics www.cell.com/cell-host-mi...
Happy to share the last publication of @bobytaillefer.bsky.social, showing that #T6SS heterogeneity is an attenuation strategy to optimizes the trade-off between competitive killing and survival.
PLOS Biology@plosbiology.org · 2mo agoThe T6SS is a widespread nanoweapon deployed by #bacteria, but why is it deployed heterogeneously? @cascaleslab.bsky.social &co show that #Ecoli adopt distinct #T6SS attacker "ON" & defender "OFF" roles to optimize survival, a key strategy in microbial warfare @plosbiology.org 🧪 plos.io/3S5dL45
New in JB: Yue, Larson et al. connect de novo spermidine synthesis and exogenous supply of this molecule to fitness and rapid growth of Francisella tularensis, providing clues to how to stop this and other pathogens. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
Finally out in @Cellcellpress! Proteins with long IDRs are prone to misfolding during protein synthesis. This is prevented by mRNA 3′UTRs that act as mRNA-based IDR chaperones. www.cell.com/cell/fulltex...
mRNA 3′ UTRs chaperone intrinsically disordered regions to control protein activity
Highly conserved mRNA 3′ UTRs act as co-translational chaperones for intrinsically disordered regions (IDRs), preventing inter-domain misfolding and enabling biogenesis of fully active proteins.
cell.com
JB Editor's Choice: Jakowec, Finkel et al. explore the roles of glycogen and trehalose in adapting to stationary phase by E. coli - they show that loss of either "misaligns" metabolism and transcription during this period of stress. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
JB Editor's Choice: Pope, Paczkowski et al. find RhlR ligand-binding pocket mutants that enhance sensitivity to C4HSL w/o changing selectivity & see specific effects on phenazine gene expression, uncovering a new means to tune QS systems. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
Spatial and genetic constraints govern transcription–translation coupling and mRNA degradation in bacteria -in @natmicrobiol.nature.com www.nature.com/articles/s41...
Spatial and genetic constraints govern transcription–translation coupling and mRNA degradation in bacteria - Nature Microbiology
RNase E localization and translation initiation coordinate transcription, translation and mRNA degradation during the life cycle of an mRNA, explaining gene- and species-specific variations in this co...
nature.com
New in JB: Papangeli, Dubern et al. study one of my favorite proteins in P. aeruginosa - SadB, which was shown previously to play a role in biofilm formation. These authors show a global role for SadB, including in virulence & QS gene expression. journals.asm.org/doi/10.1128/... @asm.org #JBacteriol
Exploring bet-hedging in Salmonella enterica serovar Typhimurium with a dual reporter strain [including in vivo during Caenorhabditis elegans infection] #mSystems from @aaronwhiteley.bsky.social journals.asm.org/doi/10.1128/...
Exploring bet-hedging in Salmonella enterica serovar Typhimurium with a dual reporter strain | mSystems
Salmonella strains that cause gastroenteritis remain a leading cause of illness and deaths related to foodborne disease. These bacteria follow a cyclical life cycle (i.e., host → environment → host) that is key to their continued success as pathogens. Here, we built a dual reporter strain to study the infectious single cells and biofilm cell types of Salmonella enterica serovar Typhimurium, one of the most common gastroenteritis-causing serovars worldwide. Studying infectious and persistent cell types simultaneously and how they interact with host tissues in vivo will provide new insights into the Salmonella lifecycle and will be important to develop interventions that reduce outbreaks and disease.
journals.asm.org
Premature transcription termination modulates stochastic gene expression in bacteria trp operon in E.coli vs B.subtilis -in Science Advances from Christoph Engl www.science.org/doi/10.1126/...
Premature transcription termination modulates stochastic gene expression in bacteria
Bacteria tune transcription bursts through early termination, enabling switch-like and gradual adaptation to nutrients.
science.org
Mfd interacts with RNA polymerase to modulate flagellum-dependent motility, chemotaxis, and population heterogeneity in the stationary phase of Bacillus subtilis in J Bacteriol journals.asm.org/doi/10.1128/...
Mfd interacts with RNA polymerase to modulate flagellum-dependent motility, chemotaxis, and population heterogeneity in the stationary phase of Bacillus subtilis | Journal of Bacteriology
The mutation frequency decline (Mfd) enzyme mediates transcription-coupled repair in transcribed genes by directly interacting with RNA polymerase (RNAP) during transcription of coding sequences. Howe...
journals.asm.org
Enterococcus faecalis not only antagonizes Pseudomonas aeruginosa growth under iron limitation, but also induces a unique transcriptional profile, enhancing P. aeruginosa survival during antibiotic challenge. Learn more in #JBacteriology: asm.social/2Wg
George O'Toole (he/him/his)@geiselbiofilm.bsky.social · 3mo agoNew in JB: How the Pts system impacts carbon metabolism is well known (if not, read this article!). Banerjee, Cabeen & Chandler review nitrogen-related phosphotransferase systems & their role in virulence, physiology, and central metabolism. journals.asm.org/doi/10.1128/... @asm.org #JBacteriology
New in JB: How the Pts system impacts carbon metabolism is well known (if not, read this article!). Banerjee, Cabeen & Chandler review nitrogen-related phosphotransferase systems & their role in virulence, physiology, and central metabolism. journals.asm.org/doi/10.1128/... @asm.org #JBacteriology
New in JB: García-Reyes, González-Pedrajo et al. review Role of PsrA, a TetR-family transcriptional regulator, in physiology and virulence regulation in P. aeruginosa. PsrA links long-chain fatty acids to the control of gene expression. journals.asm.org/doi/10.1128/... @asm.org #JBacteriology
