Pulldown of human serum proteins with Trypanosoma brucei Invariant Surface Glycoprotein 75
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Blood Serum
SUBMITTER: 
Qi Wu
LAB HEAD: Christian Brix Folsted Andersen
PROVIDER: PXD047614 | Pride | 2024-02-06
REPOSITORIES: Pride
Similar Datasets
Project description:Antigenic variation is employed by many pathogens to evade the host immune response, and Trypanosoma brucei has evolved a complex system to achieve this phenotype, involving sequential use of variant surface glycoprotein (VSG) genes encoded from a large repertoire of ~2,000 alleles. T. brucei express multiple, sometimes closely related, VSGs in a population at any one time, and the ability to resolve and analyse this diversity has been limited. We applied long read sequencing (PacBio) to VSG amplicons generated from blood extracted from batches of mice sacrificed at time points (days 3, 6, 10 and 12) post-infection with T. brucei TREU927. The data showed that long read sequencing is reliable for resolving allelic differences between VSGs, and demonstrated that there is significant expressed diversity (449 VSGs detected across 20 mice) and across the timeframe of study there was a clear semi-reproducible pattern of expressed diversity (median of 27 VSGs per sample at day 3 post infection (p.i.), 82 VSGs at day 6 p.i., 187 VSGs at day 10 p.i. and 132 VSGs by day 12 p.i.). There was also consistent detection of one VSG dominating expression across replicates at days 3 and 6, and emergence of a second dominant VSG across replicates by day 12, providing further evidence for hierarchical VSG expression, a conclusion that was confirmed by the novel application of diversity analysis to VSG expression. Our results indicate that long read analysis is a reliable tool for resolving diverse allele expression profiles, and provides novel insights into the complexity and nature of VSG expression in trypanosomes, revealing significantly higher diversity than previously shown and identifying mosaic gene formation unprecedentedly early during the infection process.
2018-11-01 | GSE114843 | GEO
Project description:The human N-terminal acetyltransferase E (NatE) including its associated NatA co-translationally acetylates the N-terminus of about 40-60% of the proteome to mediate diverse biological processes including protein half-life, localization and protein interaction. In eukaryotes, the NatE complex contains the NAA50 catalytic subunit with substrate specificity for N-terminal methionine acetylation and NatA, which facilitates ribosomal targeting of the complex for co-translational activity. NatA, contains NAA10 catalytic and NAA15 auxiliary subunits, and forms a complex with a protein with intrinsic NAA10 inhibitory activity, HYPK. The molecular basis for how the human NAA10 and NAA50 catalytic subunits within NatE complex coordinate function and how HYPK regulates NatE activity is unknown. Here, we characterize the biochemical interplay between the human NAA10 and NAA50 catalytic subunits of NatE and its regulation by HYPK and correlate this to the cryo-EM structures of the human NatE and NatE/HYPK complexes. We show that NAA50 and HYPK exhibit negative cooperative binding to NatA in vitro and in human cells, by inducing NAA15 shifts in opposing directions. NAA50 and HYPK each contributes to NAA10 activity inhibition through structural alteration of the NAA10 substrate binding site. NatE is about 8-fold more active than NAA50, likely due to a reduced entropic cost for substrate binding through NatA tethering, but is inhibited by HYPK through structural alteration of the NatE substrate binding site. Taken together, these studies reveal the molecular basis for coordinated N-terminal acetylation by the NAA10 and NAA50 catalytic subunits of NatE and its modulation by HYPK.
2020-03-13 | PXD017031 | Pride
Project description:T. brucei regularly switches its major surface antigen, VSG, to evade the mammalian host immune response. VSGs are expressed from subtelomeric loci in a strictly monoallelic manner. We identify POLIE as an intrinsic component of the T. brucei telomere complex and examined the effect of POLIE depletion on VSG expression regulation by RNAseq.
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Project description:Cytoplasmic lipid droplets (LDs) are found in all types of plant cells where they are derived from the endoplasmic reticulum (ER) and function as a repository for neutral lipids, as well as serving in lipid remodelling and signalling. However, the mechanisms underlying the formation and functioning of plant LDs, particularly in non-seed tissues, are relatively unknown. Previously, we showed that the LD-Associated Proteins (LDAPs) are a family of plant-specific, LD surface-associated coat proteins that are required for proper LD biogenesis and neutral lipid homeostasis in vegetative tissues. Here, we screened a yeast two-hybrid library using Arabidopsis LDAP3 as ‘bait’ in an effort to identify other novel LD protein constituents. One of the candidate LDAP3-interacting proteins was Arabidopsis At5g16550, which is a plant-specific protein of unknown function that we termed LDIP (LDAP-interacting protein). Using a combination of biochemical and cellular approaches, we show that LDIP targets specifically to the LD surface, contains a discrete amphipathic -helical targeting sequence, and participates in both homotypic and heterotypic associations with itself and LDAP3, respectively. Analysis of LDIP T-DNA knockdown and knockout mutants showed a decrease in LD abundance and increase in variability of LD size in leaves, with concomitant increases in total neutral lipid content. Similar phenotypes were observed in plant seeds, which showed enlarged LDs and increases in total seed oil amounts. Collectively, these data identify LDIP as a new player in LD biogenesis in plants that modulates both LD size and cellular neutral lipid homeostasis. Potential mechanisms of LDIP activity are discussed.
2017-11-06 | PXD007192 | Pride
Project description:The infectious metacyclic forms of Trypanosoma brucei result from a complex development in the tsetse fly vThe infectious metacyclic forms of Trypanosoma brucei result from a complex development in the tsetse fly vector. When they infect mammals, they cause African sleeping sickness in humans. Due to scarcity of biological material and difficulties of the tsetse fly as an experimental system, very limited information is available concerning the gene expression profile of metacyclic Trapanosoma forms. We used an in vitro system based on expressing the RNA binding protein 6 (RBP6) to obtain infectious metacyclics and determined their protein and mRNA repertoires by mass-spectrometry (MS) based proteomics and mRNA sequencing (RNAseq) in comparison to non-infectious procyclic trypanosomes. This comparison showed that metacyclics are quiescent cells, and we propose this influences the choice of a monocistronic variant surface glycoprotein expression site. Metacyclics have a largely bloodstream-form type transcriptome, and thus are programmed to translate a bloodstream-form type proteome upon entry into the mammalian host and resumption of cell division. Genes encoding cell surface components showed the largest changes between procyclics and metacyclics, observed at both the transcript and protein levels. Genes encoding metabolic enzymes exhibited expression in metacyclics with features of both procyclic and bloodstream forms, suggesting that this intermediate-type metabolism is dictated by the availability of nutrients in the tsetse fly vector. ector. When they infect mammals, they cause African sleeping sickness in humans. Due to scarcity of biological material and difficulties of the tsetse fly as an experimental system, very limited information is available concerning the gene expression profile of metacyclic Trapanosoma forms. We used an in vitro system based on expressing the RNA binding protein 6 (RBP6) to obtain infectious metacyclics and determined their protein and mRNA repertoires by mass-spectrometry (MS) based proteomics and mRNA sequencing (RNAseq) in comparison to non-infectious procyclic trypanosomes. This comparison showed that metacyclics are quiescent cells, and we propose this influences the choice of a monocistronic variant surface glycoprotein expression site. Metacyclics have a largely bloodstream-form type transcriptome, and thus are programmed to translate a bloodstream-form type proteome upon entry into the mammalian host and resumption of cell division. Genes encoding cell surface components showed the largest changes between procyclics and metacyclics, observed at both the transcript and protein levels. Genes encoding metabolic enzymes exhibited expression in metacyclics with features of both procyclic and bloodstream forms, suggesting that this intermediate-type metabolism is dictated by the availability of nutrients in the tsetse fly vector.
2017-07-31 | PXD006197 | Pride
Project description:Trypanosoma brucei parasites successfully evade the host immune system by periodically switching the dense coat of Variant Surface Glycoproteins (VSG) at the cell surface. Each parasite expresses VSGs in a monoallelic fashion that is tightly regulated. The consequences of exposing multiple VSGs during an infection in terms of antibody response and disease severity remain unknown. In this study, we overexpressed a high mobility group box protein, TDP1, which was sufficient to open the chromatin of silent VSG expression sites, to disrupt VSG monoallelic expression and to generate viable and healthy parasites with a mixed VSG coat. Mice infected with these parasites mounted a multi-VSG antibody response, which rapidly reduced parasitemia. Consequently, we observed a prolonged mice survival in which nearly 90% of the mice survived a 30-day period infection with undetectable parasitemia. Immunodeficient RAG2 knock-out mice were unable to control the infection with TDP1-overexpressing parasites, showing that the adaptive immune response is critical to reduce disease severity. This study shows that simultaneous exposure of multiple VSGs is highly detrimental for the parasite even at the very early stages of infection, suggesting that drugs that disrupt VSG monoallelic expression could be used to treat trypanosomiasis.
2019-09-13 | PXD014803 | Pride
Project description:T cells from several blood donors were separated in populations corresponding to CD8+ CD28+ and CD8+ CD28- surface markers. Total RNA extracts from cells were hybridized to MRC LNA microarray. Contrasts of interest were CD8CD28- minus CD8CD28+ (replicative aging) and CD8CD28+ (old donors) minus CD8CD28+ (young donors), which corresponds to chronological aging.
2010-04-19 | E-MEXP-2398 | biostudies-arrayexpress
Project description:Trypanosoma brucei is a protozoan parasite that causes human African trypanosomiasis. Its major surface antigen VSG is expressed from subtelomeric loci in a strictly monoallelic manner. We previously showed that the telomere protein TbRAP1 binds dsDNA through its 737RKRRR741 patch to silence VSGs globally. How TbRAP1 permits transcription of the single active VSG is unknown. Through NMR structural analysis, we unexpectedly identify an RNA Recognition Motif (RRM) in TbRAP1, which is unprecedented for RAP1 homologs. Assisted by the 737RKRRR741 patch, TbRAP1 RRM recognizes consensus sequences of VSG 3’UTRs in vitro and binds the active VSG RNA in vivo. Mutating conserved RRM residues abolishes the RNA binding activity, significantly decreases the active VSG RNA level, and derepresses silent VSGs. The competition between TbRAP1’s RNA and dsDNA binding activities suggests a novel mechanism of monoallelic expression, in which the active VSG’s abundant RNA antagonizes TbRAP1’s silencing effect, thereby sustaining its full-level transcription.
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Project description:Background Dendritic cells (DC) represent the major cell type leading to polarized T helper (Th) cell responses in vivo. The current data indicate that DC maturation under inflammatory conditions or by helminth infections induce only incomplete DC maturation bearing a partially tolerogenic potential. Such semi-mature DC promoted a Th2 profile with increasing proportions of regulatory IL-10 producing T cells (Tr-1) upon restimulation. Methodology/Principal Findings Here we asked whether the instruction of DC by the proinflammatory cytokine TNF is qualitatively different from maturation by two types of variant surface glycoproteins (VSGs) of Trypanosoma brucei. We tested differentially matured murine bone marrow (BM)-derived DC for changes in surface markers or cytokines, by microarray analyses, for their induction of Th2 responses and their capacity to influence the disease models asthma for Th2 immunity and experimental autoimmune encephalomyelitis (EAE) for a Th1/Th17 response. Conclusions/Significance Together, our data suggest that the partial maturation signatures induced by TNF and VSG antigens are highly similar and result in comparable Th2/Tr1 profiles, effects on asthma and EAE. This is remarkable since the responses resulting from endogenous inflammatory TNF-receptor signals or exogenous pathogenic MyD88 ligands are comparable. total samples analysed are 5
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Project description:To assess if newly synthesised ribosomal proteins participate in canonical ribosome biogenesis in the nucleus, following their enhanced translation upon protrusion induction, Light (L) SILAC labelled MDA-MB231 breast cancer cells were seeded on top of collagen-I coated 3 micron transwell filters (corning). No media was added to the bottom chamber and cells were allowed to adhere to filter overnight. The next day, the media on top of cells was replaced with either medium (M) (closed pores) or heavy (H) SILAC media to pulse label newly synthesised proteins. H media was also added to the bottom chamber (open pores) in order to allow formation of protrusions in the H condition. Cells were pulsed for 4 hrs before being lysed and H and M pulsed samples were mixed together. Mixed lysates were then subjected to subcellular fractionation by serial solubilization (cytosol, membrane and nucleus) using Pierce subcellular protein fractionation kit (78840).
2020-10-20 | PXD021205 | Pride