Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

SpxA1 and SpxA2 Function as a Stoichiometry-Dependent Regulatory Rheostat Governing Virulence Gene Expression in Group A Streptococcus — NanoString nCounter dataset

ABSTRACT: Group A Streptococcus (GAS) encodes two paralogs of the Spx transcriptional regulator, SpxA1 and SpxA2, which interact with RNA polymerase to modulate virulence gene expression. SpxA2 is directly regulated by the LiaFSR three-component system in response to antimicrobial peptide (AMP) stress. To define how SpxA1 and SpxA2 influence virulence gene expression under cell envelope stress, we performed NanoString nCounter analysis using a custom 119-probe codeset (116 endogenous targets plus 3 housekeeping probes: tufA, gyrA, guaB) in wild-type MGAS10870 (emm3) and isogenic deletion mutants (deltaSpxA1 and deltaSpxA2) under three conditions: uninduced (UI), sub-MIC bacitracin (BAC), and sub-MIC human neutrophil peptide-1 (hNP-1). Differential expression analysis identified condition- and paralog-specific changes in CovR-regulated virulence factor-encoding genes consistent with a stoichiometry-dependent regulatory model.

ORGANISM(S): Streptococcus pyogenes MGAS10870

PROVIDER: GSE334410 | GEO | 2026/07/13

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

SpxA1 and SpxA2 Function as a Stoichiometry-Dependent Regulatory Rheostat Governing Virulence Gene Expression in Group A Streptococcus — RNA-seq dataset

Project description:Group A Streptococcus (GAS) encodes two paralogs of the Spx transcriptional regulator, SpxA1 and SpxA2, which interact with RNA polymerase to modulate virulence gene expression. To define the transcriptomic consequences of SpxA1 and SpxA2 loss, we performed strand-non-specific paired-end RNA-seq in the wild-type emm3 GAS strain MGAS10870 and isogenic deletion mutants (deltaSpxA1 and deltaSpxA2) grown to mid-exponential phase in Todd-Hewitt broth supplemented with 0.2% yeast extract (THY). Differential expression analysis identified distinct transcriptomic signatures for each paralog, with SpxA1 primarily influencing oxidative stress response genes and SpxA2 modulating CovR-regulated virulence factor-encoding genes. These data contribute to a multi-omic analysis including DIA proteomics, NanoString nCounter, and CovR ChIP-exo that defines the regulatory roles of SpxA1 and SpxA2 in GAS pathogenesis.

2026-07-13 | GSE334312 | GEO

SpxA1 and SpxA2 Function as a Stoichiometry-Dependent Regulatory Rheostat Governing Virulence Gene Expression in Group A Streptococcus — CovR ChIP-exo dataset

Project description:Group A Streptococcus (GAS) encodes two paralogs of the Spx transcriptional regulator, SpxA1 and SpxA2, which interact with RNA polymerase to modulate virulence gene expression. SpxA2 is directly regulated by the LiaFSR three-component system in response to antimicrobial peptide stress. To define how SpxA2 influences CovR DNA occupancy genome-wide, we performed chromatin immunoprecipitation with exonuclease treatment (ChIP-exo) targeting CovR in wild-type MGAS10870 (emm3), an isogenic spxA2 deletion mutant (deltaSpxA2), and a LiaSQ146A constitutively active LiaS mutant used as a SpxA2 overexpression surrogate (SpxA2-OE). Differential binding analysis identified 439 sites with significantly altered CovR occupancy between wild-type and deltaSpxA2 (FDR < 0.05), with class-specific enrichment of CovR dimer and monomer binding motifs consistent with the two-class CovR binding model (Horstmann et al. 2023). These data contribute to a multi-omic analysis including RNA-seq, DIA proteomics, and NanoString nCounter that defines the regulatory roles of SpxA1 and SpxA2 in GAS pathogenesis.

2026-07-13 | GSE334313 | GEO

Microarray analysis of genes regulated by SpxA1 and SpxA2 in Streptococcus suis serotype 2

2014-06-07 | GSE56760 | GEO

Microarray analysis of genes regulated by SpxA1 and SpxA2 in Streptococcus suis serotype 2

Project description:To reveal the scope of the Spx regulation and explore the differences in the regulatory roles of SpxA1 and SpxA2, the global gene transcription profiles of the WT, M-bM-^HM-^FspxA1 and M-bM-^HM-^FspxA2 strains were determined by DNA microarray analysis performed using an Agilent custom-designed oligonucleotide microarray. S. suis strains were grown in TSB with 10% (vol/vol) newborn bovine serum to mid-exponential phase. Total RNA was isolated using an SV total RNA isolation system (Promega), according to the manufacturerM-bM-^@M-^Ys recommended protocol. RNA concentrations and integrity were determined using an Agilent 2100 Bioanalyzer.Two biological replicates of total RNA from WT strain and three from each mutant strain were used for array.

2014-06-07 | E-GEOD-56760 | biostudies-arrayexpress

A new Rrf2 repressor family member, SaiR, controls transcription of spxA2 encoding a regulator of the oxidative stress response in Bacillus anthracis.

Project description:Spx, a member of the ArsC (arsenate reductase) protein family, is highly conserved in Gram-positive bacteria, where it interacts with RNA polymerase to activate transcription in response to toxic oxidants. In Bacillus anthracis, resistance to oxidative stress requires the activity of two paralogous forms of Spx, SpxA1 and SpxA2. Suppressor mutations were identified in spxA1 mutant cells that conferred resistance to hydrogen peroxide. The mutations, which reside in saiR within the operon that also contains the spxA2 gene, caused derepression of spxA2 transcription. The product of saiR is a member of the Rrf2 family of transcriptional repressors. Derepression of spxA2 in a saiR mutant required SpxA2, indicating an autoregulatory mechanism of spxA2 transcriptional activation. Reconstruction of SaiR-dependent control of spxA2 was accomplished in Bacillus subtilis, where deletion analysis uncovered two cis-elements within the spxA2 regulatory region that are required for repression. Both sites bear sequences of dyad symmetry, mutations in which abolished SaiR binding and SaiR-dependent repression of transcription from the spxA2 promoter in vitro. Previous studies have provided evidence that spxA2 is one of the most highly induced genes in a macrophage infected with B. anthracis. The work reported herein uncovered a key regulator, SaiR, which controls spxA2 transcriptional activation.

2014-05-21 | GSE57851 | GEO

A new Rrf2 repressor family member, SaiR, controls transcription of spxA2 encoding a regulator of the oxidative stress response in Bacillus anthracis.

Project description:Spx, a member of the ArsC (arsenate reductase) protein family, is highly conserved in Gram-positive bacteria, where it interacts with RNA polymerase to activate transcription in response to toxic oxidants.Â In Bacillus anthracis, resistance to oxidative stress requires the activity of two paralogous forms of Spx, SpxA1 and SpxA2.Â Â Suppressor mutations were identified in spxA1 mutant cells that conferred resistance to hydrogen peroxide. Â The mutations, which reside in saiR within the operon that also contains the spxA2 gene, caused derepression of spxA2 transcription. The product of saiR is a member of the Rrf2 family of transcriptional repressors. Â Derepression of spxA2 in a saiR mutant required SpxA2, indicating an autoregulatory mechanism of spxA2 transcriptional activation. Â Reconstruction of SaiR-dependent control of spxA2 was accomplished in Bacillus subtilis, where deletion analysis uncovered two cis-elements within the spxA2 regulatory region that are required for repression.Â Both sites bear sequences of dyad symmetry, mutations in which abolished SaiR binding and SaiR-dependent repression of transcription from the spxA2 promoter in vitro.Â Previous studies have provided evidence that spxA2 is one of the most highly induced genes in a macrophage infected with B. anthracis.Â The work reported herein uncovered a key regulator, SaiR, which controls spxA2 transcriptional activation. Direct comparison of experimental samples to control samples in a two-color hybridization. Two experimental samples were compared against two control samples in triplicate for each.

2014-05-21 | E-GEOD-57851 | biostudies-arrayexpress

spxA1-null mutant of Streptococcus sanguinis SK36

Project description:Transcriptional profiling of the spxA1-null mutant of Streptococcus sanguinis SK36 compared with wild type. The spxA1 gene was inactivated in Streptococcus sanguinis SK36, and the mutant demonstrated opaque colony morphology, reduced hydrogen peroxide (H2O2) production, and reduced antagonistic activity against Streptococcus S. mutans UA159 both on plates and in liquid media. The mutant also showed decreased tolerance to high temperature, and acidic and oxidative stresses. Complementation of the ΔspxA1 mutant with spxA1 restored colony morphology, H2O2 production and stress tolerance to the ΔspxA1 mutant. The mutant also exhibited an ~5-fold reduction in competitiveness in an animal model of endocarditis, indicating the involvement of SpxA1 in endocarditis virulence. Microarray studies revealed that a number of SpxA1-upregulated genes are involved in oxidative stress. The expression of spxB and nox (which encode pyruvate oxidase and NADH oxidase, respectively, and are involved in H2O2 production and nox involved virulence) significantly decreased in ΔspxA1 compared with the wild type. This may be at least partly responsible for the decreased H2O2 production and reduced virulence in the ΔspxA1 mutant because spxB and nox were involved in H2O2 production and nox involved virulence.

2011-12-08 | GSE34203 | GEO

spxA1-null mutant of Streptococcus sanguinis SK36

2011-12-08 | E-GEOD-34203 | biostudies-arrayexpress

The impacts of the Spx regulator and H2O2 stress on the transcriptome of Streptococcus mutans

Project description:As a resident of the oral cavity, Streptococcus mutans must withstand a variety of stresses, including oxidative stress. Previously, we reported the identification of two Spx homologues (SpxA1 and SpxA2) in Streptococcus mutans that appear critical in the ability of the microbe to tolerate oxidative stresses; SpxA1 was shown to play a primary role in activation of detoxification strategies whereas SpxA2 served as a secondary activator. Here, we used RNA deep sequencing (RNA-Seq) to examine the transcriptional changes associated with H2O2 stress in the parent S. mutans strain UA159 and to compare the peroxide-stress transcriptome of UA159 with its Δspx derivatives. The transcriptome data confirmed the relationship between SpxA1 and genes typically associated with oxidative stress responses, but also identified new genes and metabolic pathways that are activated during peroxide stress, also in an SpxA1-dependent manner.

2017-05-08 | GSE98526 | GEO