Toxoplasma gondii
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ABSTRACT:
PROVIDER: PRJNA116441 | ENA |
REPOSITORIES: ENA
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Project description:Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although still little is known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. Here, we investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase (HDAC) inhibitor. We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi such as TSA and the clinically relevant compound, pyrimethamine. We identify TgHDAC3 as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (non replicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of ~370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDAC inhibitor of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and likely other Apicomplexa.
2009-03-19 | GSE15241 | GEO
Project description:Apicomplexa are intracellular parasites that cause human and animal disease. They proliferate by a unique mechanism that combines closed mitosis with daughter cell budding. In past work we demonstrated that the Toxoplasma gondii centromeres are sequestered to the nuclear periphery proximal to the centrosome throughout the cell cycle. Here we show that interphase centromere clustering is not mediated by the mitotic spindle. Instead we propose a chromatin model of centromere clustering and define structural maintenance of chromosomes protein 1 (SMC1) as a persisting centromeric protein. We biochemically identify proteins that physically interact with SMC1, and CenH3 (a centromeric histone); prominent among those are predicted peripheral soluble components of the nuclear pore complex including TgExportin1. Treatment of parasites with the highly specific exportin1 inhibitor leptomycin B causes the dispersal of centromeres. Our results suggest that the nuclear envelope, and in particular peripheral components of the nuclear transport machinery orchestrate centromere positioning and parasite nuclear architecture. Chromatin immunoprecipitation (ChIP) of TgSMC1, three replicates applied to two microarrays each representing half of the Toxoplasma genome
2014-09-27 | E-GEOD-61806 | biostudies-arrayexpress
Project description:Developmental regulation of the intracellular parasite Toxoplasma gondii is an understudied topic despite being central for a bid to control its dissemination around the globe. Of particular neglect are the factors that contribute to its sexual development. While it has previously been shown that generalized transcriptional repression machinery plays an important role in silencing spurious gene expression of sexually-committed parasites, the specific factors that target the generalized machinery to genetic loci remains unexplored. Here, we uncover that a member of the AP2 transcription factor family, AP2XII-2, is targeted to genomic loci that are associated with sexually-committed parasites along with the generalized regulators of transcriptional silencing, HDAC3 and MORC. Despite widespread association with gene promoters, AP2XII-2 is required for silencing of relatively few genes. We place two genes associated with sexual development downstream of AP2XII-2 control, transcription factor AP2X-10 and the amino acid hydroxylase AAH1. Dissecting gene regulatory pathways of Toxoplasma sexual development will likely be essential for controlling Toxoplasma dissemination in the future.
2023-01-24 | GSE217220 | GEO
Project description:Apicomplexa are intracellular parasites that cause human and animal disease. They proliferate by a unique mechanism that combines closed mitosis with daughter cell budding. In past work we demonstrated that the Toxoplasma gondii centromeres are sequestered to the nuclear periphery proximal to the centrosome throughout the cell cycle. Here we show that interphase centromere clustering is not mediated by the mitotic spindle. Instead we propose a chromatin model of centromere clustering and define structural maintenance of chromosomes protein 1 (SMC1) as a persisting centromeric protein. We biochemically identify proteins that physically interact with SMC1, and CenH3 (a centromeric histone); prominent among those are predicted peripheral soluble components of the nuclear pore complex including TgExportin1. Treatment of parasites with the highly specific exportin1 inhibitor leptomycin B causes the dispersal of centromeres. Our results suggest that the nuclear envelope, and in particular peripheral components of the nuclear transport machinery orchestrate centromere positioning and parasite nuclear architecture.
2014-09-27 | GSE61806 | GEO
Project description:We describe the cell cycle transcriptome of the Toxoplasma gondii that has emerged as a major genetic model for the study of Apicomplexa parasites. Two distinct transcriptional waves accompany the relatively simple binary replication of tachyzoite stage (endodyogeny) functionally separating conserved gene expression in the eukaryotic G1 phase from the lineage-specific expression that predominates in the parasite S phase and mitotic periods. This division of transcriptional focus closely mirrors the intimate relationship that has evolved between mitosis and building of the daughter parasites and invasion organelles. Promoter mechanisms appear to orchestrate the induction of gene expression in dividing tachyzoites with up to two dozen cell cycle AP2 factors likely acting within a transcriptional regulatory network to coordinate the parasite cell cycle transcriptome.
2010-08-27 | GSE19092 | GEO
Project description:Developmental regulation of the intracellular parasite Toxoplasma gondii is an understudied topic despite being central for a bid to control its dissemination around the globe. Of particular neglect are the factors that contribute to its sexual development. While it has previously been shown that generalized transcriptional repression machinery plays an important role in silencing spurious gene expression of sexually-committed parasites, the specific factors that target the generalized machinery to genetic loci remains unexplored. Here, we uncover that a member of the AP2 transcription factor family, AP2XII-2, is targeted to genomic loci that are associated with sexually-committed parasites along with the generalized regulators of transcriptional silencing, HDAC3 and MORC. Despite widespread association with gene promoters, AP2XII-2 is required for silencing of relatively few genes. We place two genes associated with sexual development downstream of AP2XII-2 control, transcription factor AP2X-10 and the amino acid hydroxylase AAH1. Dissecting gene regulatory pathways of Toxoplasma sexual development will likely be essential for controlling Toxoplasma dissemination in the future.
2023-01-24 | GSE217226 | GEO
Project description:We describe the cell cycle transcriptome of the Toxoplasma gondii that has emerged as a major genetic model for the study of Apicomplexa parasites. Two distinct transcriptional waves accompany the relatively simple binary replication of tachyzoite stage (endodyogeny) functionally separating conserved gene expression in the eukaryotic G1 phase from the lineage-specific expression that predominates in the parasite S phase and mitotic periods. This division of transcriptional focus closely mirrors the intimate relationship that has evolved between mitosis and building of the daughter parasites and invasion organelles. Promoter mechanisms appear to orchestrate the induction of gene expression in dividing tachyzoites with up to two dozen cell cycle AP2 factors likely acting within a transcriptional regulatory network to coordinate the parasite cell cycle transcriptome. To characterize the cell cycle transcriptome of Toxoplasma tachyzoites, we expanded a thymidine-synchrony model to isolate sufficient RNA for microarray expression studies. The ToxoGeneChip microarray (http://ancillary.toxodb.org/docs/Array-Tutorial.html) was used to measure mRNA expression in 13 duplicate samples (R0 to R12) covering 12 hours post-synchronization and nearly two tachyzoite replication cycles.
2010-08-27 | E-GEOD-19092 | biostudies-arrayexpress
Project description:Plasmodium and Toxoplasma are parasites of major medical importance that belong to the Apicomplexa phylum of protozoa. These parasites transform into various stages during their life cycle and express a specific set of proteins at each stage. Although still little is known of how gene expression is controlled in Apicomplexa, histone modifications, particularly acetylation, are emerging as key regulators of parasite differentiation and stage conversion. Here, we investigated the anti-Apicomplexa effect of FR235222, a histone deacetylase (HDAC) inhibitor. We show that FR235222 is active against a variety of Apicomplexa genera, including Plasmodium and Toxoplasma, and is more potent than other HDACi such as TSA and the clinically relevant compound, pyrimethamine. We identify TgHDAC3 as the target of FR235222 in Toxoplasma tachyzoites and demonstrate the crucial role of the conserved and Apicomplexa HDAC-specific residue TgHDAC3 T99 in the inhibitory activity of the drug. We also show that FR235222 induces differentiation of the tachyzoite (replicative) into the bradyzoite (non replicative) stage. Additionally, via its anti-TgHDAC3 activity, FR235222 influences the expression of ~370 genes, a third of which are stage-specifically expressed. These results identify FR235222 as a potent HDAC inhibitor of Apicomplexa, and establish HDAC3 as a central regulator of gene expression and stage conversion in Toxoplasma and likely other Apicomplexa. Freshly released tachyzoites were needle-passed, and filtered using a 3-µm nucleopore membrane. Parasites were resuspended into fresh DMEM supplemented with 10% (v/v) FBS and 25 mM HEPES buffer pH7.2. Parasites were incubated in the presence of FR235222 (40 nM) or DMSO (0.1%) for 4 h at 37°C with 5% CO2. For ChIP-chip experiments freshly released tachyzoites (~5 x 109 at ~12 x 107 parasites/mL) were fixed for 15 min in 1% formaldehyde. Increase in AcH4 signals was verified by immunoblot to verify that FR235222 treatment was effective. To prepare chromatin samples, fixed parasites were lysed in MNase buffer (0.32 M Sucrose, 50 mM Tris-HCl pH7.8, 4 mM MgCl2, 3 mM CaCl2, 100 mM NaCl, 0.25% (v/v) NP40, 5% (v/v) glycerol, protease inhibitor EDTA-free cocktail (Roche)) and DNA was digested for 4 min at 37°C by MNase (2 units/mL). Digestion was stopped with 20 mM EDTA and chromatin was recovered in the soluble fraction after centrifugation at 10,000 g at 4°C; this constituted the S1 fractions. Pelleted materials were resuspended in dialysis buffer (1mM Tris-HCl pH7.8, 0.2 mM EDTA) containing 1 mM PMSF and protease inhibitor cocktail (Roche®) and dialyzed overnight at 4°C against the same solution. Then dialyzed materials were centrifuged and supernatant were harvested; this constitutes the S2 fractions. For chromatin immunoprecipitations, fractions S1 and S2 were pooled and DNA quality was verified by electrophoresis on 2% agarose gels; oligonucleosome ladder of 100-1000 bp were obtained. The histone-DNA complexes were immunoprecipitated with anti-acetyl histone H4 (Upstate®, catalog # 06-866) antibodies according to NimbleGenâs protocol (http://www.genomecenter.ucdavis.edu/expression_analysis/documents).
2010-06-21 | E-GEOD-15241 | biostudies-arrayexpress
Project description:Lysine methylation on histone tails impacts genome regulation and cell fate determination in many developmental processes. Apicomplexa intracellular parasites cause major diseases and they have developed complex life cycles with fine-tuned differentiation events. Yet, apicomplexa genomes have few transcription factors and little is known about their epigenetic control systems. Tick-borne Theileria apicomplexa species have relatively small, compact genomes and a remarkable ability to transform leukocytes in their bovine hosts. Here we report enriched H3 lysine 18 monomethylation (H3K18me1) on the gene bodies of repressed genes in Theileria macroschizonts. Differentiation to merozoites (merogony) led to decreased H3K18me1 in parasite nuclei. Pharmacological manipulation of H3K18 acetylation or methylation impacted parasite differentiation and expression of stage-specific genes. Finally, we identified a parasite SET-domain methyltransferase (TaSETup1) that can methylate H3K18 and represses gene expression. Thus, H3K18me1 emerges as an important epigenetic mark which controls gene expression and stage differentiation in Theileria parasites.
2021-03-25 | PXD024599 | Pride
Project description:Genomic Localization of TgSMC1 in Toxoplasma gondii parasites
| PRJNA262179 | ENA