Project description:Streptococcus pneumoniae D39 AdcR (adhesion competence repressor) is the first metal-sensing member of the MarR (multiple antibiotic resistance repressor) family to be characterized. Expression profiling of a âadcR strain grown in liquid culture under microaerobic conditions revealed that transcript amounts for 13 genes were up-regulated relative to the wild-type strain, among them adcR, adcCBA, encoding a high affinity ABC uptake system for zinc, and genes encoding cell-surface zinc-binding pneumococcal histidine triad (pht) and adcII (lmb, laminin binding) proteins. Down-regulated transcripts included those encoding two putative zinc-containing alcohol dehydrogenases. Bacterial strains were grown exponentially in rich (BHI) media at 37C and an atmosphere of 5% CO2 to OD620~0.2, and were processed as described in the related Sample records. Samples were collected from three independent biological replicates and included one dye swap. Data were normalized using the Lowess (block) method without background subtraction. Changes in relative transcript amounts of positive or negative 2-fold with Bayesian P value of <0.001 were considered significant, and were included as supplementary material for the accompanying manuscript (The metalloregulatory site in Streptococcus pneumoniae AdcR, a zinc-activated MarR-family repressor; Reyes-Caballero, H. et al, manuscript in preparation).
Project description:Streptococcus pneumoniae D39 AdcR (adhesion competence repressor) is the first metal-sensing member of the MarR (multiple antibiotic resistance repressor) family to be characterized. Expression profiling of a ∆adcR strain grown in liquid culture under microaerobic conditions revealed that transcript amounts for 13 genes were up-regulated relative to the wild-type strain, among them adcR, adcCBA, encoding a high affinity ABC uptake system for zinc, and genes encoding cell-surface zinc-binding pneumococcal histidine triad (pht) and adcII (lmb, laminin binding) proteins. Down-regulated transcripts included those encoding two putative zinc-containing alcohol dehydrogenases.
Project description:Zinc is an essential divalent trace metal for living cells. Intracellular zinc homeostasis is critical to the pathogenicity and virulence of bacteria, however the strategies of zinc homeostasis maintain in Streptococcus mutans, an important causative pathogen of dental caries, is unknown. In this study, we examined the function of an ABC transporter AdcCBA and its transcription factor AdcR in S. mutans. Using RNA-Seq analysis, LacZ-reporter studies and gel mobility shift assay, we showed that a MarR family transcription factor AdcR directly regulates the activity of promoters of adcRCB and adcA in response to the concentration of zinc in their environmental niches. Deletion of adcR increases the sensitivity of S. mutans to excessive zinc supply. Taken together, our finding suggests that Adc regulon, consists of a zinc uptake transporter AdcCBA and a zinc-responsive repressor AdcR, plays a prominent role in the maintenance of intracellular zinc homeostasis of S. mutans.
Project description:In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our M-NM-2-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5M-bM-^@M-^Y-ATATTGTGCTCAAATA-3M-bM-^@M-^Y) for UlaR2 binding in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell that leads to the activation of the AdcR regulon. Comparison of the Streptococcus pneumoniae D39 ulaR2 mutant compared to D39 wild type in M17 medium+ 10mM ascorbic acid (AM17) One condition design comparision of two strains including a dye swap
Project description:In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our M-NM-2-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5M-bM-^@M-^Y-ATATTGTGCTCAAATA-3M-bM-^@M-^Y) for UlaR2 binding in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell that leads to the activation of the AdcR regulon. Comparison of the Streptococcus pneumoniae D39 compared to D39 wild type in M17 medium+ 10mM ascorbic acid (AM17) Two conditions design comparision of one strain including a dye swap
Project description:Zinc (Zn2+) is an important trace metal ion that has been shown to regulate the expression of several (virulence) genes in streptococci. Previously, we analyzed the genome-wide response of S. pneumoniae to Zn2+-stress. In this work, we have performed a transcriptomic analysis to identify genes that are differentially expressed under intracellular Zn2+-limitation. This revealed a number of genes that are highly upregulated in the absence of extracellular Zn2+, amongst which the genes belonging to the regulon of the Zn2+-responsive repressor AdcR, like adcBCA, encoding a Zn2+-dependent ABC-uptake system, adcAII, encoding a Zn2+-binding lipoprotein, and also virulence genes belonging to the Pht family (phtA, phtB, phtD and phtE). Using transcriptome analysis, lacZ-reporter studies, in vitro DNA binding experiments, and in silico operator predictions, we show that AdcR directly represses the promoters of adcRCBA, adcAII-phtD, phtA, phtB and phtE in the presence of Zn2+. AdcR can also function as an activator, since in the presence of Zn2+ it directly induces expression of adh that encodes a Zn2+-containing alcohol dehydrogenase. In conclusion, the genome-wide transcriptional response of S. pneumoniae to Zn2+-limitation was established, which is mainly mediated via direct regulation by the Zn2+-dependent regulator AdcR. This SuperSeries is composed of the SubSeries listed below.
Project description:In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our β-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5’-ATATTGTGCTCAAATA-3’) for UlaR2 binding in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell that leads to the activation of the AdcR regulon. This SuperSeries is composed of the SubSeries listed below.
Project description:Zinc (Zn2+) is an important trace metal ion that has been shown to regulate the expression of several (virulence) genes in streptococci. Previously, we analyzed the genome-wide response of S. pneumoniae to Zn2+-stress. In this work, we have performed a transcriptomic analysis to identify genes that are differentially expressed under intracellular Zn2+-limitation. This revealed a number of genes that are highly upregulated in the absence of extracellular Zn2+, amongst which the genes belonging to the regulon of the Zn2+-responsive repressor AdcR, like adcBCA, encoding a Zn2+-dependent ABC-uptake system, adcAII, encoding a Zn2+-binding lipoprotein, and also virulence genes belonging to the Pht family (phtA, phtB, phtD and phtE). Using transcriptome analysis, lacZ-reporter studies, in vitro DNA binding experiments, and in silico operator predictions, we show that AdcR directly represses the promoters of adcRCBA, adcAII-phtD, phtA, phtB and phtE in the presence of Zn2+. AdcR can also function as an activator, since in the presence of Zn2+ it directly induces expression of adh that encodes a Zn2+-containing alcohol dehydrogenase. In conclusion, the genome-wide transcriptional response of S. pneumoniae to Zn2+-limitation was established, which is mainly mediated via direct regulation by the Zn2+-dependent regulator AdcR. Two condition design comparison of Wild-type strain including a dye swap Refer to individual Series. This SuperSeries is composed of the following subset Series: GSE29234: adcR mutant vs wild type D39 GSE29235: Low Zn vs high Zn in CDM
Project description:By using the transcriptomic approach, we have elucidated the effect of Ni2+ on the global gene expression of S. pneumoniae D39 by identifying several differentially expressed genes/operons in the presence of a high extracellular concentration of Ni2+. The genes belonging to the AdcR regulon (adcRCBA, adcAII-phtD, phtA, phtB and phtE) and the PsaR regulon (pcpA, prtA and psaBCA) were highly upregulated in the presence of Ni2+. We have further studied the role of Ni2+ in the regulation of the AdcR regulon by using ICP-MS analysis, electrophoretic mobility shift assays and transcriptional lacZ-reporter studies, and demonstrate that Ni2+ is directly involved in the derepression of the AdcR regulon via the Zn2+-dependent repressor AdcR, and has an opposite effect on the expression of the AdcR regulon as compared to Zn2+. Comparison of the Streptococcus pneumoniae D39 wild-type vs D39 ÎadcR in CDM Plus 0.3 mM Ni2+ Two condition design comparison of Wild-type strain vs mutant strain including a dye swap
Project description:By using the transcriptomic approach, we have elucidated the effect of Ni2+ on the global gene expression of S. pneumoniae D39 by identifying several differentially expressed genes/operons in the presence of a high extracellular concentration of Ni2+. The genes belonging to the AdcR regulon (adcRCBA, adcAII-phtD, phtA, phtB and phtE) and the PsaR regulon (pcpA, prtA and psaBCA) were highly upregulated in the presence of Ni2+. We have further studied the role of Ni2+ in the regulation of the AdcR regulon by using ICP-MS analysis, electrophoretic mobility shift assays and transcriptional lacZ-reporter studies, and demonstrate that Ni2+ is directly involved in the derepression of the AdcR regulon via the Zn2+-dependent repressor AdcR, and has an opposite effect on the expression of the AdcR regulon as compared to Zn2+. This SuperSeries is composed of the SubSeries listed below.