Similar Datasets
Project description:The Staphylococcus aureus two-component regulatory system, SrrAB, coordinates hypoxic responses during in vitro growth conditions. S. aureus Affymetrix GeneChips were used to compare S. aureus expression properties of wild type and isogenic ssrA mutant cells during aerobic growth conditions. S. aureus Affymetrix GeneChips were also used to compare the S. aureus expression properties of wild type and isogenic ssrA mutant cells during hypoxic growth conditions. Few differences were observed between the expression properties of S. aureus wildtype and ssrA mutant cells during aerobic growth. Significant differences were observed between the expression properties of S. aureus wild type and ssrA mutant cells during hypoxic growth.
2015-12-01 | GSE75516 | GEO
Project description:LeuO, initially identified as a leucine regulator in Escherichia coli, has since been identified as a global regulator required for bacterial pathogenicity in a broad range of bacteria, including gram-negative pathogens, such as Salmonella, Shigella, and Vibrio; and gram-positive bacteria, such as Streptococcus pneumoniae. However, the regulatory roles and targets of LeuO vary among species. In the Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium), LeuO represses the transcription of Salmonella pathogenicity island (SPI)-1, thus diminishing the ability of the bacteria to invade host cells. However, its regulatory effect on SPI-2, essential for survival within macrophages, remains poorly understood. This study aimed to determine the regulatory role of LeuO in the intracellular persistence of S. Typhimurium. Overexpression of LeuO repressed the transcription of SPI-2 genes and accordingly decreased its protein levels. Chromatin immunoprecipitation sequencing revealed the genome-wide binding sites of LeuO in S. Typhimurium 14028 and identified a distinctive 23-nucleotide motif with high similarity to that previously discovered in E. coli. Notably, multiple LeuO-binding sites were predicted within SPI-2, primarily adjacent to the ssrA and ssrB loci. In vitro binding assays verified the high binding affinity between LeuO and three specific motifs located at positions -35 to -12 (ssrA1),+231 to +254 (ssrA2) near ssrA, and at positions -622 to -599 (ssrB3) near ssrB, relative to their transcription start sites. Furthermore, LeuO overexpression abolished the transcription of lacZ fused to the ssrA promoter containing ssrA1 and ssrA2, suggesting the direct repression of ssrA via LeuO-binding. The absence of LeuO increased the intracellular survival of S. Typhimurium within macrophages, whereas its overexpression attenuated bacterial persistence, which was presumably associated with the downregulation of SPI-2 by LeuO. This study reveals the versatile regulatory mechanisms of LeuO and underscores its pivotal role in modulating SPI-2 expression, thereby providing key insights into the fine tuning of virulence by Salmonella during systemic infection.
2024-11-14 | GSE280231 | GEO
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
2023-01-30 | GSE212242 | GEO
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
2023-01-30 | GSE212239 | GEO
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
2023-01-30 | GSE212238 | GEO
Project description:A new variant of group A Streptococcus (GAS) serotype M1 (designated ‘M1UK’) has been reported in the United Kingdom, linked with seasonal scarlet fever surges, marked increase in invasive infections, and exhibiting enhanced expression of the superantigen SpeA. The progenitor GAS ‘M1global’ and M1UK clones can be differentiated by 27 SNPs and 4 indels, yet the mechanism for speA upregulation is unknown. Here we investigate the previously unappreciated expansion of M1UK in Australia, now isolated from the majority of serious infections caused by serotype M1 GAS. M1UK sub-lineages circulating in Australia also contain a novel toxin repertoire associated with epidemic scarlet fever causing GAS in Asia. A single SNP in the M1UK tmRNA gene ssrA drives enhanced SpeA superantigen expression as a result of ssrA terminator readthrough in the M1UK lineage. This represents a new paradigm of toxin expression and urges enhanced international surveillance.
2023-01-30 | GSE212241 | GEO
Project description:To elucidate whole-transcriptome changes in stationary-phase of growth of L. monocytogenes induced by inactivation of lmo0946 gene, we performed transcriptome comparison of wild-type and its derivative mutant in lmo0946 gene. The analysis revealed very high abundance of two non-coding RNAs, namely Rli47 (sRNA) and SsrA (tmRNA) in both studied strains.
2023-08-05 | E-MTAB-10810 | biostudies-arrayexpress
Project description:Tn-seq of ssrA deletion mutant of Bacillus subtilis
| PRJDB17234 | ENA
Project description:We used a combination of genetic and proteomic approaches to characterize tmRNA (ssrA) activity in the genome-reduced bacterium Mycoplasma pneumoniae. For this, we generated tmRNA mutants encoding a tag resistant to proteolysis. Endogenous protein tagging by the mutant tmRNA gene (ssrAmk) was then examined by immunoprecipitation (IP) enrichment followed by LC-MS/MS analysis.
2021-08-23 | PXD023973 | Pride
Project description:We used a combination of genetic and proteomic approaches to characterize tmRNA (ssrA) activity in the genome-reduced bacterium Mycoplasma pneumoniae. For this, we generated tmRNA mutants encoding a tag resistant to proteolysis. Endogenous protein tagging by the mutant tmRNA gene (ssrAmk) was then examined by immunoprecipitation (IP) enrichment followed by LC-MS/MS analysis. Additionally, RNA-seq differential expression analysis of the mutants compared to the wild-type strain was assessed.
2021-08-09 | E-MTAB-10111 | biostudies-arrayexpress