A procedure to identify peptides with α-AMP activity
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ABSTRACT:
PROVIDER: PRJEB13158 | ENA |
REPOSITORIES: ENA
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Project description:We showed previously that insertion of Synechocystis 12-desaturase in Salmonellas membrane alters membrane physical state (MPS) followed by the expression of stress genes causing inability to survive within murine macrophages . Recently, we showed that expression of one membrane lipid domain (MLD) of 12-desaturase (ORF200) interferes with Salmonella MPS causing loss of virulence in mice and immunoprotection. We postulated that a putative -AMP intercalates specifically within phospholipids but, depending on its amino acid sequence, does so within particular key sensors of MLD. In this study we choose as target for a putative synthetic AMP, PhoP/PhoQ, a sensor that responds to low Mg2+ concentration during murine macrophages infection. We synthesized a modified DNA fragment coding for an amino acid sequence (NUF) similar to that fragment and expressed it in Salmonella LT2 strain. We show that the pattern of gene expression controlled by PhoP/PhoQ and other pathways involving phospholipids biosynthesis, stress proteins and genes coding for antigens are dysregulated. We also present RNAseq of strain expressing ORF200 and showed that the pattern of the same genes is altered. Accumulation of NUF conferred temporary immunoprotection suggesting that it is possible to address a synthetic peptide to a specific MLD. This represents a powerful procedure to synthesize -AMPs and generate live non virulent strains for vaccination.
2016-07-15 | E-MTAB-4544 | biostudies-arrayexpress
Project description:Obtaining an in depth understanding of the arms races between peptides comprising the innate immune response and bacterial pathogens is of fundamental interest and will inform the development of new antibacterial therapeutics. Many cationic antimicrobial peptides (AMPs) share a range of structural and physical features that have been linked to antibacterial activity and yet they vary dramatically in their potency towards the same bacterial target. We hypothesised that a whole organism view of AMP challenge on Escherichia coli could provide a sophisticated, bacterial perspective enabling understanding of how potency is linked to mode of action. We used a 1H NMR metabolomic approach to characterise the effect on E. coli of challenge with four structurally and physically related AMPs: magainin 2, pleurocidin, buforin II and a designed peptide comprising D-amino acids only. Sub-inhibitory conditions, where these peptides nevertheless induced a bacterial response, were identified enabling electron microscopic and transcriptomic analyses. Although some common features of the bacterial response to AMP challenge could be identified, the metabolomes, morphological changes and the vast majority of the changes in gene expression were specific to each AMP. We show the antibacterial mode of action of AMPs can be accurately predicted by comparing ontological profiles generated by transcriptomic analyses. The response of E. coli to AMP challenge is highly plastic, with the bacteria capable of deploying a multifaceted response adapted to the mode of action rather than the physical properties of the AMP.
2014-01-21 | E-MTAB-1703 | biostudies-arrayexpress
Project description:flue-curing procedure Raw sequence reads
| PRJNA685271 | ENA
Project description:Invertebrate antimicrobial peptides (AMPs) form the first line of defence against pathogenic microbes. Understanding AMP profiles in helminths, their importance to helminth biology, and how they shape microbial communities could reveal novel approaches for anthelmintic and/or antimicrobial development. In this study, we employed a LC-MS/MS peptidomics pipeline to validate a novel integrated homology- and computational-based pipeline for the discovery of helminth AMPs. Our peptidomics pipeline found 60 high-confidence PSMs correlating to 15 high-confidence novel AMP-LPs within Ascaris suum body-cavity fluid supporting the need for further characterisation of these peptides and their functions within helminths.
2023-07-26 | PXD042293 | Pride
Project description:Despite continuing advances in the development of novel cellular-, antibody-, and chemotherapeutic-based strategies to enhance immune reactivity, the presence of regulatory T cells (Tregs) remains a complicating factor to their clinical efficacy. To overcome dosing limitations and off-target effects from antibody-based Treg deletional strategies, we investigated the ability of hydrocarbon stapled alpha-helical (SAH) peptides to target FOXP3, the master transcription factor regulator of Treg development, maintenance, and suppressive function. Using the crystal structure of the FOXP3 homodimer as a guide, we developed SAHs in the likeness of a portion of the native FOXP3 antiparallel coiled-coil homodimerization domain (SAH-FOXP3) to block this key FOXP3 protein-protein interaction (PPI) through molecular mimicry. We show that lead SAH-FOXP3s bind FOXP3, are cell permeable, non-toxic to T cells, induce dose-dependent transcript and protein level alterations of FOXP3 target genes, impede Treg function, and lead to Treg gene expression changes in vivo consistent with Foxp3 dysfunction.
2022-09-29 | GSE201116 | GEO
Project description:C-di-AMP is primarily associated with the regulation of carbon utilization as well as other central traits, central metabolism, and bacterial stringent response to environmental changes. Elevated c-di-AMP levels result in aberrant physiology for most c-di-AMP synthesizing organisms, drawing particular attention to the importance of the c-di-AMP homeostasis and the molecular mechanisms pertaining to nucleotide metabolism and signal transduction. Here we show that c-di-AMP binds the GntR-family regulator DasR, uncovering a direct link between c-di-AMP and GlcNAc signaling. Further, we show c-di-AMP functions as an allosteric activator of DasR activity. GlcNAc is necessary for cell-surface structure from bacteria to humans, as well as a signal for bacterial development and antibiotic production. DasR is a global repressor that oversees GlcNAc metabolism and antibiotic production, which enables Actinobacteria to cope with stress and starvation. Our in vivo studies reveal the important biological role of allosteric regulation by c-di-AMP in metabolic imbalance and the transduction of a series of signals. Notably, DasR also controls intracellular c-di-AMP level through direct repression on disA. Overall, we identify a function of allosteric regulation between c-di-AMP and DasR in global signal integration and c-di-AMP homeostasis in bacteria, which is likely widespread in Actinobacteria.
2024-03-31 | GSE229938 | GEO
Project description:It is well appreciated that reactive oxygen species (ROS) are deleterious to mammals, including humans, especially when generated in abnormally large quantities from cellular metabolism. Whereas the mechanisms leading to the production of ROS are rather well delineated, the mechanisms underlying tissue susceptibility or tolerance to oxidant stress remain elusive. Through an experimental selection over many generations, we have previously generated Drosophila melanogaster flies that tolerate tremendous oxidant stress and have shown that the family of antimicrobial peptides (AMP) is over-represented in these tolerant flies. Furthermore, we have also demonstrated that overexpression of even one AMP at a time (e.g. Diptericin) allows wild type flies to survive much better in hyperoxia. In the current study, we used a number of experimental approaches to investigate the potential mechanisms underlying hyperoxia tolerance in flies with antimicrobial peptide overexpression. We demonstrate that flies with Diptericin overexpression resist oxidative stress by increasing antioxidant enzyme activities and preventing an increase in ROS level after hyperoxia. Depleting the GSH pool using buthionine sulfoximine limits fly survival, thus confirming that enhanced survival observed in these flies is related to improved redox homeostasis. We conclude that a) AMPs play an important role in tolerance to oxidant stress; b) overexpression of Diptericin changes the cellular redox balance between oxidant and antioxidant, and c) this change in redox balance plays an important role in survival in hyperoxia. Expression profiles of Drosophila melanogaster with anti-microbial peptide over-expression (experimental sample; n=3) and controls (UAS-AMP alone not crossed to da-GAL4; n=3) were determined using Affymetrix Drosophila Genome 2.0 Arrays.
2010-12-21 | E-GEOD-23902 | biostudies-arrayexpress
Project description:Streptococcus pneumoniae harbors two cyclic di-AMP (c-di-AMP) phosphodiesterases Pde1 and Pde2. Previously, we demonstrated that deletion of one or both of these proteins leads to growth retardation in culture media, defects in the bacterial stress response, and attenuation in mouse models of disease. All of these phenotypes are due to increased levels of c-di-AMP, since the nature and break down products of each protein are different, and mutations that lower c-di-AMP levels partially restore growth and stress tolerance in these mutants. However, how c-di-AMP mediates pneumococcal stress resistance and virulence is unknown. To establish how c-di-AMP affects the transcriptome, RNA-Seq analysis was employed to compare gene expression between wild-type and Δpde1Δpde2 (ST2734) pneumococci. Overall, the competence regulon was upregulated in the Δpde1Δpde2 mutant.
2018-04-18 | GSE113231 | GEO
Project description:Total RNAs were extracted from internodes and roots of 18 day-after-germination soybean plants, and the expression levels of the genes that encode xylem sap associated peptides or proteins were analyzed.
2015-10-23 | E-MTAB-5052 | biostudies-arrayexpress
Project description:20(S)-Protopanaxadiol (PPD) and 20(S)-Protopanaxatriol (PPT) are major metabolites of ginseng in humans and are considered to have estrogenic activity in cellular bioassays. In this study, we conducted in silico analyses to determine whether PPD and PPT interact with estrogen receptor alpha (ERα) and compared them with ERα agonists, partial agonists, and antagonists to identify their ERα activity.
2021-10-26 | GSE186470 | GEO