Sialic acid-mediated gene expression in Streptococcus pneumoniae and the role of NanR as a transcriptional activator of the nan gene cluster
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PROVIDER: PRJNA277333 | ENA |
REPOSITORIES: ENA
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Project description:In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to sialic acid (N-acetylneuraminic acid: Neu5Ac). Transcriptome comparison of the D39 wild-type grown in M17 medium with and without sialic acid revealed the elevated expression of various genes and operons including the nan gene cluster (nan operon-I and nanA gene). Our microarray analysis and promoter-lacZ fusion studies showed that the transcriptional regulator NanR acts as a transcriptional activator of nan operon-I and the nanA gene in the presence of sialic acid. The putative regulatory site of NanR in the promoter region of nan operon-I is predicted and confirmed by promoter truncation experiments. Furthermore, the role of CcpA in the regulation of the nan gene cluster is demonstrated through microarray analysis and promoter-lacZ fusion studies, suggesting that in the presence of sialic acid and glucose, CcpA represses the expression of nan operon-I while the expression of the nanA gene is CcpA-independent. This SuperSeries is composed of the SubSeries listed below.
2015-03-06 | GSE66561 | GEO
Project description:Members of the genus Bifidobacterium are typically found in the gastrointestinal tract (GIT) of humans and other mammals. Bifidobacterium breve strains are numerically prevalent among the gut microbiota of healthy, breast-fed infants. The metabolism of sialic acid, a ubiquitous monosaccharide in the infant and adult gut, by B. breve UCC2003 is dependent on a large gene cluster, designated the nan/nag cluster. This study describes the transcriptional regulation of the nan/nag cluster and thus sialic acid metabolism in B. breve UCC2003. Insertion mutagenesis and transcriptome analysis revealed that the nan/nag cluster is regulated by a GntR family transcriptional repressor, designated NanR. NanR was shown to bind to two promoter regions within this cluster, each of which containing an imperfect inverted repeat that is believed to act as the NanR operator sequence. Formation of the DNA-NanR complex is prevented in the presence of sialic acid, which we had previously shown to induce transcription of this gene cluster. NanR represents the first GntR-type transcriptional regulator to be characterised from bifidobacteria.
2015-03-05 | GSE62885 | GEO
Project description:Members of the genus Bifidobacterium are typically found in the gastrointestinal tract (GIT) of humans and other mammals. Bifidobacterium breve strains are numerically prevalent among the gut microbiota of healthy, breast-fed infants. The metabolism of sialic acid, a ubiquitous monosaccharide in the infant and adult gut, by B. breve UCC2003 is dependent on a large gene cluster, designated the nan/nag cluster. This study describes the transcriptional regulation of the nan/nag cluster and thus sialic acid metabolism in B. breve UCC2003. Insertion mutagenesis and transcriptome analysis revealed that the nan/nag cluster is regulated by a GntR family transcriptional repressor, designated NanR. NanR was shown to bind to two promoter regions within this cluster, each of which containing an imperfect inverted repeat that is believed to act as the NanR operator sequence. Formation of the DNA-NanR complex is prevented in the presence of sialic acid, which we had previously shown to induce transcription of this gene cluster. NanR represents the first GntR-type transcriptional regulator to be characterised from bifidobacteria. DNA-microarrays containing oligonucleotide primers representing each of the 1864 annotated genes on the genome of B. breve UCC2003 (O'Connell Motherway et al., 2011) were designed by and obtained from Agilent Technologies (Palo Alto, Ca., USA). Methods for cell disruption, RNA isolation, RNA quality control, complementary DNA synthesis and labeling were performed as described previously (Pokusaeva et al., 2009). Labeled cDNA was hybridized using the Agilent Gene Expression hybridization kit (part number 5188-5242) as described in the Agilent Two-Color Microarray-Based Gene Expression Analysis v4.0 manual (G4140-90050). Following hybridization, microarrays were washed in accordance with Agilent’s standard procedures and scanned using an Agilent DNA microarray scanner (model G2565A). Generated scans were converted to data files with Agilent's Feature Extraction software (Version 9.5). DNA-microarray data were processed as previously described (Garcia De La Nava et al., 2003). Differential expression tests were performed with the Cyber-T implementation of a variant of the t-test (Long et al., 2001). A gene was considered differentially expressed when p < 0.001 and an expression ratio of >3 or <0.33 relative to the control.
2015-03-05 | E-GEOD-62885 | biostudies-arrayexpress
Project description:In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to sialic acid (N-acetylneuraminic acid [Neu5Ac]). Transcriptome comparison of wild-type D39 grown in M17 medium with and without sialic acid revealed the elevated expression of various genes and operons, including the nan gene cluster (nan operon I and nanA gene). Our microarray analysis and promoter-lacZ fusion studies showed that the transcriptional regulator NanR acts as a transcriptional activator of nan operon I and the nanA gene in the presence of sialic acid. The putative regulatory site of NanR in the promoter region of nan operon I is predicted and confirmed by promoter truncation experiments. Furthermore, the role of CcpA in the regulation of the nan gene cluster is demonstrated through microarray analysis and promoter-lacZ fusion studies, suggesting that in the presence of sialic acid and glucose, CcpA represses the expression of nan operon I while the expression of the nanA gene is CcpA independent.
| S-EPMC4393437 | biostudies-literature
Project description:Bifidobacteria constitute a specific group of commensal bacteria which inhabit the gastrointestinal tract of humans and other mammals. Bifidobacterium breve UCC2003 has previously been shown to utilise several plant-derived carbohydrates that include cellodextrins, starch and galactan. In the current study, we investigate the ability of this strain to utilise the mucin- and human milk oligosaccharide (HMO)-derived carbohydrate, sialic acid. Using a combination of transcriptomic and functional genomic approaches, we identified a gene cluster dedicated to the uptake and metabolism of sialic acid. Furthermore, we demonstrate that B. breve UCC2003 can cross feed on sialic acid derived from the metabolism of 3’ sialyllactose, a HMO, by Bifidobacterium bifidum PRL2010.
2014-05-29 | GSE56291 | GEO
Project description:Bifidobacteria constitute a specific group of commensal bacteria which inhabit the gastrointestinal tract of humans and other mammals. Bifidobacterium breve UCC2003 has previously been shown to utilise several plant-derived carbohydrates that include cellodextrins, starch and galactan. In the current study, we investigate the ability of this strain to utilise the mucin- and human milk oligosaccharide (HMO)-derived carbohydrate, sialic acid. Using a combination of transcriptomic and functional genomic approaches, we identified a gene cluster dedicated to the uptake and metabolism of sialic acid. Furthermore, we demonstrate that B. breve UCC2003 can cross feed on sialic acid derived from the metabolism of 3’ sialyllactose, a HMO, by Bifidobacterium bifidum PRL2010. DNA-microarrays containing oligonucleotide primers representing each of the 1864 annotated genes on the genome of B. breve UCC2003 (O'Connell Motherway et al., 2011) were designed by and obtained from Agilent Technologies (Palo Alto, Ca., USA). Methods for cell disruption, RNA isolation, RNA quality control, complementary DNA synthesis and labeling were performed as described previously (Pokusaeva et al., 2009). Labeled cDNA was hybridized using the Agilent Gene Expression hybridization kit (part number 5188-5242) as described in the Agilent Two-Color Microarray-Based Gene Expression Analysis v4.0 manual (G4140-90050). Following hybridization, microarrays were washed in accordance with Agilent’s standard procedures and scanned using an Agilent DNA microarray scanner (model G2565A). Generated scans were converted to data files with Agilent's Feature Extraction software (Version 9.5). DNA-microarray data were processed as previously described (Garcia De La Nava et al., 2003). Differential expression tests were performed with the Cyber-T implementation of a variant of the t-test (Long et al., 2001). A gene was considered differentially expressed when p < 0.001 and an expression ratio of >3 or <0.33 relative to the control.
2014-05-29 | E-GEOD-56291 | biostudies-arrayexpress
Project description:Transcriptome comparison of the Streptococcus pneumoniae D39 wild-type grown in M17 medium toD39 wild-type grown in M17 medium + 0.5% sialic acid (SM17).
2015-03-06 | GSE66560 | GEO
Project description:Influenza A viruses (IAV) cause seasonal outbreaks that pose a substantial burden on human health. They are also a zoonotic threat as avian and swine IAV can be a source for pandemic influenza. Receptor specificity is a critical determinant of tropism, host range and transmissibility of IAV and thus, plays a crucial role in zoonotic IAV infections1-3. Avian, swine and human IAV bind sialic acid on host cell glycans as their common receptor but differ in sialic acid specificity4,5. In contrast, bat IAV of the H17 and H18 subtypes cannot use sialic acid and require MHC class II complexes for host cell entry6-8. It is unknown how this difference in receptor specificity evolved and if dual receptor specificity for sialic acid and MHC class II is possible. Here, we show that human H2N2 IAV and related avian H2N2 possess dual receptor specificity. In addition to their known sialic acid-dependent entry they can use MHC class II as alternative entry pathway, independent of sialic acid. Of note, MHC class II from humans, pigs, ducks, swans and chickens but not from bats can mediate H2 IAV entry and the ability to use this alternative entry pathway is conserved in current Eurasian avian H2 IAV. Our results demonstrate that IAV can possess dual receptor specificity for sialic acid and MHC class II and suggest a role for MHC class II-dependent entry in zoonotic IAV infections.
2024-06-17 | GSE264198 | GEO
Project description:Sialylation, and its modifications, have important consequences for development, differentiation and immune system regulation in nearly all human tissues. An accounting of all the genes responsible for modifying sialic acids is incomplete, with only one pathway for O-acetylation being well-defined in humans. Using whole genome sequencing of normal human colorectal tissue we identify a haplotype on chromosome 11 that is associated with differences in mild periodic acid Schiff staining (mPAS), a marker of acetylation of sialic acids. Of the genes in this region, only SNPs from NXPE1 correlate perfectly in a validation data set. NXPE1 protein expression by IHC also correlates with mPAS staining patterns in homozygous, as well as heterozygous colon crypts that have undergone spontaneous gain of the mPAS phenotype. Manipulation of NXPE1 expression with CRISPR-Cas9 causes changes to modified sialic acid levels in both 2D cell line and 3D normal colon organoid models. These findings suggest NXPE1 may cause O-acetylation of sialic acids in colorectal tissue, potentially defining NXPE as a new family of sialic acid-modifying genes.
| EGAS00001007704 | EGA
Project description:Transcriptome comparison of the Streptococcus pneumoniae D39 ΔccpA to D39 wild-type grown in M17 medium + 0.5% sialic acid (SM17).
2015-03-06 | GSE66559 | GEO