Molecular singularities in a pheromone sensor triumvirate desynchronize the competence-predation interplay in the human commensal Streptococcus salivarius
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA493819 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR7942380.fastq.gz | Fastqsanger.gz | |||
| SRR7942390.fastq.gz | Fastqsanger.gz | |||
| SRR7942371.fastq.gz | Fastqsanger.gz | |||
| SRR7942381.fastq.gz | Fastqsanger.gz | |||
| SRR7942391.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 24 |
Similar Datasets
Project description:The human oral cavity is one of the most competing environments, considering the extent and diversity of the bacterial community that colonizes it, as well as the multiple stresses to which it is subjected. The commensal species Streptococcus salivarius is one of the first colonizers of the oral mucosa (tongue, gums, inner cheeks and tooth enamel) in infants and remains predominant throughout the life of an adult. In order to adapt to diverse and variable environmental conditions, S. salivarius triggers in a coordinated way two bacterial developmental processes: competence (acquisition of extracellular DNA and new genetic traits) and predation (secretion of cytotoxic molecule), via ComR, a transcription factor activatable by a "pheromone" peptide. Nevertheless, the activation of other transcriptional regulators can uncouple these 2 mechanisms to allow, for example, only the production of toxins without triggering the competence phase.
2019-08-19 | GSE120640 | GEO
Project description:Small distortions in transcriptional networks might lead to drastic phenotypical changes, especially in cellular developmental programs such as competence for natural transformation. Here, we report a pervasive circuitry rewiring for competence and predation interplay in commensal streptococci. Canonically, in model species of streptococci such as Streptococcus pneumoniae and Streptococcus mutans, the pheromone-based two-component system BlpRH is a central node that orchestrates the production of antimicrobial compounds (bacteriocins) and incorporates signal from the competence activation cascade. However, the human commensal Streptococcus salivarius does not contain a functional BlpRH pair and in this species, the competence signaling system ComRS directly couples bacteriocin production and competence commitment. This network shortcut might account for an optimal reaction against microbial competitors and could explain the high prevalence of S. salivarius in the human digestive tract. Moreover, the broad spectrum of bacteriocin activity against pathogenic bacteria showcases the commensal and genetically tractable S. salivarius species as a user-friendly model for natural transformation and bacterial predation.
2018-01-10 | GSE100416 | GEO
Project description:The CovR environmental sensor orchestrates competence bimodality in salivarius streptococci
| PRJNA665491 | ENA
Project description:Constantly surrounded by kin or alien organisms in nature, eukaryotes and prokaryotes developed various communication systems to coordinate adaptive multi-entity behavior. In complex and overcrowded environments, they require to discriminate relevant signals in a myriad of pheromones to execute appropriate responses. In the human gut commensal Streptococcus salivarius, the cytoplasmic Rgg/RNPP regulator ComR couples competence to bacteriocin-mediated predation. Here, we describe a paralogous sensor duo, ScuR and SarF, which circumvents ComR in order to disconnect these two physiological processes. We highlighted the recurring role of Rgg/RNPP in the production of antimicrobials and designed a robust genetic screen to unveil potent/optimized peptide pheromones. Further mutational and biochemical analyses dissected the modifiable selectivity toward their pheromone and operating sequences at the subtle molecular level. Additionally, our results highlight how we might mobilize antimicrobial molecules while silencing competence in endogenous populations of human microflora and temper gut disorders provoked by bacterial pathogens.
| S-EPMC6703854 | biostudies-literature
Project description:In bacteria, phenotypic heterogeneity rescues the need for diversity in isogenic populations and allow concomitant multiple survival strategies when choosing only one is too risky. This powerful tactic is exploited for competence in streptococci and results in a bimodal activation, where only a subset of the community triggers the system. Deciphering the mechanisms underlying this puzzling behavior has remained challenging, especially since its study has been mainly achieved in S. mutans, where two different but interconnected regulation networks control competence. In this work, we sought to determine the origin of bimodality associated to the ComRS system thanks to the simplified S. salivarius model that harbors no supplemental signaling system. Using a single cell fluorescence reporter system together with the overexpression of the main actors of the regulation network, we showed that the ComR intracellular concentration is directly linked to the proportion of competent cells in the population. We report that this type of activation requires a functional positive feedback loop acting on comS through Opp and a putative ComS exporter, PptAB. To determine the origin of the heterogeneity amplified by the loop, we developed a mathematical model suggesting that either noise on ComS or ComR abundance could explain bimodality. Because ComR abundance is central for competence bimodal activation, we conducted an in silico identification and a systematic deletion of all the Two Component Systems (TCS) present in S. salivarius and identified CovRS, a well described virulence regulator in GAS and GBS, as a repressor of comR transcription. In vitro direct binding of CovR with the promoter of comR and transcriptomics confirmed those data. As CovRS integrates environmental stimuli that control ComR intracellular concentration, it represents the missing puzzle piece bridging environmental conditions and competence (bimodal) activation in salivarius streptococci.
2021-01-31 | GSE158512 | GEO
Project description:Synchronizing production of antibacterial compounds and integration of DNA released by dead cells, competence is one of the most efficient bacterial evolutionary and adaptative strategies. In most streptococci, this tactic is orchestrated by the ComRS system, a pheromone communication device providing competence bimodal initiation and sharp time window of activation. Understanding how this developmental process integrates multiple inputs to fine-tune the adequate response is a long-standing question. Actually, essential genes involved in the regulation of ComRS have been challenging to study. In this work, we built a conditional mutant library using the CRISPR-interference technology and developed three complementary screens to investigate competence genetic regulation in the human commensal Streptococus salivarius. We highlighted that competence increases upon cell-wall impairment, suggesting a connection between cell envelope stress and competence activation. Notably, we report the key role played by StkP, a serine-threonine kinase known to regulate cell-wall assembly. We showed that StkP controls competence by a mechanism responding to peptidoglycan fragments. Together, those data suggest a key cell-wall sensing mechanism coupling competence to cell envelope integrity.
2022-08-25 | GSE204976 | GEO
Project description:Whole genome expression profile comparing MGAS315 treated with XIP pheromone versus vehicle-treated cells Interpretations are described further in the manuscript to be submitted: authors Mashburn-Warren, Morrison, and Federle. Title: The Cryptic Competence Pathway in Streptococcus pyogenes is Controlled by a Peptide Pheromone.
2012-06-01 | GSE37974 | GEO
Project description:Streptococcus suis is a major pig pathogen as well as an emerging zoonotic pathogen. In a previous study (Zaccaria et al. Plos One DOI: 10.1371/journal.pone.0099394) we identified the natural pheromone-induced competence system of S. suis. To identify the mechanisms enabling competence, gene expression analysis of bacteria induced or not for competence, and in presence or absence of exogenous DNA, was assessed at 5, 15 and 45 minutes after pheromone addition. The transcriptomes showed how competence was induced and eventually shut down, and which metabolic pathways were repressed or induced when competence was active or shut down.
2017-02-09 | GSE74507 | GEO
Project description:Whole genome expression profile comparing MGAS315 treated with XIP pheromone versus vehicle-treated cells Interpretations are described further in the manuscript to be submitted: authors Mashburn-Warren, Morrison, and Federle. Title: The Cryptic Competence Pathway in Streptococcus pyogenes is Controlled by a Peptide Pheromone. A two chip study using total RNA recovered from three separate cultures of Streptococcus pyogenes MGAS315, each treated with either XIP pheromone or with vehicle; RNA preparation of cultures receiving same type of treatment were pooled using equivalent amounts of RNA from each culture. RNA pools were fluorescently labeled and hybridized to arrays designed to the S. pyogenes NZ131 genome.
2012-05-31 | E-GEOD-37974 | biostudies-arrayexpress
Project description:Candida albicans can stochastically switch between two phenotypes, white and opaque. Opaque cells are the sexually competent form of C. albicans and therefore undergo efficient polarized growth and mating in the presence of pheromone. In contrast, white cells cannot mate, but are induced - under a specialized set of conditions - to form biofilms in response to pheromone. In this work, we compare the genetic regulation of such "pheromone-stimulated" biofilms with that of "conventional" C. albicans biofilms. In particular, we examined a network of six transcriptional regulators (Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1) that mediate conventional biofilm formation for their potential roles in pheromone-stimulated biofilm formation. We show that four of the six transcription factors (Bcr1, Brg1, Rob1, and Tec1) promote formation of both conventional and pheromone-stimulated biofilms, indicating they play general roles in cell cohesion and biofilm development. In addition, we identify the master transcriptional regulator of pheromone-stimulated biofilms as C. albicans Cph1, ortholog of Saccharomyces cerevisiae Ste12. Cph1 regulates mating in C. albicans opaque cells, and here we show that Cph1 is also essential for pheromone-stimulated biofilm formation in white cells. In contrast, Cph1 is dispensable for the formation of conventional biofilms. The regulation of pheromone- stimulated biofilm formation was further investigated by transcriptional profiling and genetic analyses. These studies identified 206 genes that are induced by pheromone signaling during biofilm formation. One of these genes, HGC1, is shown to be required for both conventional and pheromone-stimulated biofilm formation. Taken together, these observations compare and contrast the regulation of conventional and pheromone-stimulated biofilm formation in C. albicans, and demonstrate that Cph1 is required for the latter, but not the former.
2013-02-22 | GSE44449 | GEO