Polyamine synthesis effects capsule expression in Streptococcus pneumoniae TIGR4
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ABSTRACT:
PROVIDER: PRJNA540495 | ENA |
REPOSITORIES: ENA
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Project description:Purpose: We recently reported that isogenic deletion of lysine decarboxylase (ΔcadA/SP_0916), an enzyme that catalyzes the biosynthesis of polyamine cadaverine in Streptococcus pneumoniae TIGR4 results in loss of capsular polysaccharide (CPS), which constitutes a novel mechanism of regulation of CPS. Here, we conducted RNA-Seq to elucidate molecular mechanisms of CPS regulation in polyamine synthesis impaired pneumococci. Result: Significantly differentially expressed genes in ΔcadA represent pneumococcal pathways involved in the biosynthesis of precursors for CPS and peptidoglycan. Conclusion: We establish a possible link and interchange between two cellular processes such as high energy demanding capsule production and oxidative stress responses in polyamine synthesis impaired pneumococci (ΔcadA).
2019-09-30 | GSE130511 | GEO
Project description:The polyamine biosynthesis gene, speE, in Streptococcus pneumoniae TIGR4 is necessary for survival in murine models of pneumococcal pneumonia. To date, there is no description of polyamine biosynthesis dependent pneumococcal gene expression. In this study, we compared gene expression between the wild-type and biosynthesis deficient (speE) TIGR4 by RNA-Seq analysis.
2023-01-01 | E-MTAB-6070 | biostudies-arrayexpress
Project description:The polyamine transport operon in Streptococcus pneumoniae TIGR4 is necessary for survival in murine models of pneumococcal pneumonia. To date, there is no description of polyamine transport dependent pneumococcal gene expression. In this study, we compared gene expression between the wild-type and transport deficient (potABCD) TIGR4 by RNA-Seq analysis.
2017-08-14 | E-MTAB-5951 | biostudies-arrayexpress
Project description:Impact of impaired polyamine biosynthesis on Streptococcus pneumoniae TIGR4 gene expression
| PRJEB22705 | ENA
Project description:Streptococcus pneumoniae (Spn), a Gram-positive bacterium, poses a significant threat to human health, causing mild respiratory infections to severe invasive conditions. Despite availability of vaccines, challenges persist due to serotype replacement and antibiotic resistance, emphasizing the need for alternative therapeutic strategies. This study explores the intriguing role of polyamines, ubiquitous, small organic cations, in modulating virulence factors, especially the capsule, a crucial determinant of Spn's pathogenicity. Utilizing chemical inhibitors, difluoromethylornithine (DFMO) and AMXT 1501, this research unveils distinct regulatory effects on the gene expression of Spn D39 serotype in response to altered polyamine homeostasis. DFMO inhibits polyamine biosynthesis, disrupting pathways associated with glucose import and interconversion of sugars. In contrast, AMXT 1501, targeting polyamine transport, enhances the expression of polyamine and glucose biosynthesis genes, presenting a novel avenue for regulating the capsule independent of glucose availability. Despite ample glucose availability, AMXT 1501 treatment downregulates glycolytic pathway, fatty acid synthesis and ATP synthase, crucial for energy production while upregulating two-component systems responsible for stress management. This suggests a potential shutdown of energy production and capsule biosynthesis, redirecting resources towards stress management. Following DFMO and AMXT 1501 treatments, countermeasures such as upregulation of stress response genes and ribosomal protein were observed but appear to be insufficient to overcome the deleterious effects on capsule production. This study highlights the complexity of polyamine-mediated regulation in S. pneumoniae, particularly, capsule biosynthesis. Our findings offer valuable insights into potential therapeutic targets for modulation of capsule in a polyamine dependent manner, a promising avenue for intervention against S. pneumoniae infections.
2024-02-28 | GSE252370 | GEO
Project description:Pancreatic ductal adenocarcinoma (PDA) cells have a distinct dependence on de novo ornithine synthesis from glutamine via ornithine aminotransferase (OAT), which supports polyamine synthesis and is required for tumor growth. This directional OAT activity is normally largely restricted to infancy and contrasts with the reliance of most adult normal tissues and other cancer types on arginase (ARG) to generate arginine-derived ornithine, the substrate for polyamine synthesis. This dependence associates with arginine depletion in PDA tumor microenvironment, and is driven by mutant KRAS, which induces the expression of OAT and polyamine synthesis enzymes, including the rate-limiting enzyme ornithine decarboxylase-1 (ODC1). Loss of OAT, but not ARG2, largely mimics loss of ODC1, altering the transcriptional profiles in PDA cells, which in turn correlate with alterations in open chromatin states.
2023-01-01 | GSE193411 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is an incurable malignant childhood brain tumour, with no active systemic therapies and a 5-year survival of less than 1%. Polyamines are small organic polycations that are essential for DNA replication, translation and cell proliferation. Ornithine decarboxylase 1 (ODC1), the rate limiting enzyme in polyamine synthesis, is irreversibly inhibited by difluoromethylornithine (DFMO). Herein we show that polyamine synthesis is upregulated in DIPG, leading to sensitivity to DFMO. DIPG cells compensate for ODC1 inhibition by upregulation of the polyamine transporter SLC3A2. Treatment with the polyamine transporter inhibitor AMXT 1501 reduced uptake of polyamines in DIPG cells, and co-administration of AMXT 1501 and DFMO led to potent in vitro activity, and significant extension of survival in three aggressive DIPG orthotopic animal models. Collectively, these results demonstrate the potential of dual targeting of polyamine synthesis and uptake as a therapeutic strategy for incurable DIPG.
| EGAS00001004905 | EGA
Project description:The aim of this experiment is to determine the difference in protein expression, if any, in a mouse model of pneumococcal pneumonia using wild type and a polyamine transport operon deletion mutant strain of S. pneumoniae TIGR4, using expression proteomics. Eight week old female C57bl/6 mice were used in this study. The experimental design had two groups of 3 animals each that were administered 50 µL 1 X 107 CFU wild type S. pneumoniae TIGR4 or S. pneumoniae TIGR4 ΔpotABCD strain by intranasal instillation. The control group with three animals received 50 µL PBS. Mice were euthanized 4 hr and 12 hr post infection and lung tissues were harvested. The control group animals were euthanized 12 hr post infection.
2018-10-27 | PXD002300 | Pride
Project description:Streptococcus pneumoniae TIGR4 Epigenomics
| PRJNA320669 | ENA
Project description:Ornithine aminotransferase supports polyamine synthesis in pancreatic cancer
| PRJNA796043 | ENA