Toxoplasma gondii arginine methyltransferase 1 (PRMT1) regulates parasite counting during tachyzoite cell division
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ABSTRACT:
ORGANISM(S): Toxoplasma gondii
PROVIDER: GSE73177 | GEO | 2015/09/18
SECONDARY ACCESSION(S): PRJNA296074
REPOSITORIES: GEO
Similar Datasets
Project description:PRMT1 is thought to be responsible for the majority of PRMT activity in Toxoplasma gondii, but its exact function is unknown. We generated T. gondii mutants lacking PRMT1 (∆prmt1) by deletion of the PRMT1 gene. ∆prmt1 parasites exhibit morphological defects during cell division and grow slowly, and this phenotype reverses in the complemented strain ∆prmt::PRMT1mRFP. PRMT1 localizes primarily in the cytoplasm with enrichment at the centrosome, and the strain lacking PRMT1 is unable to segregate progeny accurately. Unlike wild-type and complemented parasites, ∆prmt1 parasites have abnormal daughter buds, perturbed centrosome stoichiometry, and loss of synchronous replication. Whole genome expression profiling demonstrated differences in expression of cell cycle regulated genes in ∆prmt1 relative to the complemented ∆prmt1::PRMT1mRFP and parental wild-type strains, but these changes did not correlate with a specific block in cell cycle. Although PRMT1’s primary biological function was previously proposed to be methylation of histones, our genetic studies suggest that the most critical function of PRMT1 is within the centrosome as a regulator of daughter cell counting to assure the proper replication of the parasite. RNA samples were isolated in triplicates from RH-hxgprt parent strain (W), PRMT1 knockout (K) strain and PRMT1 knockout strain complemented with RFP-tagged PRMT1 protein (C). Parasites were grown for 32h at 37C. Samples were hybridized to the Toxoplasma gondii Affymetrix microarray (ToxoGeneChip: http://ancillary.toxodb.org/docs/Array-Tutorial.html). Hybridization data was preprocessed with Robust Multi-array Average (RMA) and normalized using per chip and per gene median polishing and analyzed using the software package GeneSpring GX (Agilent Technologies).
2015-09-18 | E-GEOD-73177 | biostudies-arrayexpress
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: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: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:We functionally characterized the five predicted PRMTs in Leishmania braziliensis by gene knockout and endogenous protein HA tagging using CRISPR/Cas9 gene editing. We report that R-methylation profiles vary among Leishmania species and across L. braziliensis lifecycle stages, with the peak PRMT expression occurring in promastigotes. A list of PRMT-interacting proteins was obtained in a single coimmunoprecipitation assay using HA-tagged PRMTs, suggesting a network of putative targets of PRMTs and cooperation between the R-methylation writers. Knockout of each L. braziliensis PRMT led to significant changes in global arginine methylation patterns without affecting cell viability. Deletion of either PRMT1 or PRMT3 disrupted most type I PRMT activity, resulting in a global increase in monomethyl arginine levels. Using anti-MMA antibodies, we performed an IP experiment to identify MMA proteins in the parental line, single PRMT1 knockout, PRMT1/PRMT7 double knockout and PRMT1-Addback parasites. The results indicate that R-methylation is modulated across lifecycle stages in L. braziliensis and show possible functional overlap and cooperation among the different PRMTs in targeting proteins. Overall, our data suggest important regulatory roles of these proteins throughout the L. braziliensis life cycle, showing that arginine methylation is important for parasite-host cell interactions. Linked publication: https://doi.org/10.1101/2021.09.22.461376.
2022-03-03 | PXD031057 | Pride
Project description:Developmental switching in Toxoplasma gondii, from the virulent tachyzoite to the relatively quiescent bradyzoite stage, is responsible for disease propagation and reactivation. We have generated tachyzoite to bradyzoite differentiation (Tbd-) mutants in T. gondii and used these in combination with a cDNA microarray to identify developmental pathways in bradyzoite formation. Four independently generated Tbd- mutants were analysed and had defects in bradyzoite development in response to multiple bradyzoite-inducing conditions, a stable phenotype after in vivo passages and a markedly reduced brain cyst burden in a murine model of chronic infection. Transcriptional profiles of mutant and wild-type parasites, growing under bradyzoite conditions, revealed a hierarchy of developmentally regulated genes, including many bradyzoite-induced genes whose transcripts were reduced in all mutants. A set of non-developmentally regulated genes whose transcripts were less abundant in Tbd- mutants were also identified. These may represent genes that mediate downstream effects and/or whose expression is dependent on the same transcription factors as the bradyzoite-induced set. Using these data, we have generated a model of transcription regulation during bradyzoite development in T. gondii. Our approach shows the utility of this system as a model to study developmental biology in single-celled eukaryotes including protozoa and fungi. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-08-13 | GSE3117 | GEO
Project description:Developmental switching in Toxoplasma gondii, from the virulent tachyzoite to the relatively quiescent bradyzoite stage, is responsible for disease propagation and reactivation. We have generated tachyzoite to bradyzoite differentiation (Tbd-) mutants in T. gondii and used these in combination with a cDNA microarray to identify developmental pathways in bradyzoite formation. Four independently generated Tbd- mutants were analysed and had defects in bradyzoite development in response to multiple bradyzoite-inducing conditions, a stable phenotype after in vivo passages and a markedly reduced brain cyst burden in a murine model of chronic infection. Transcriptional profiles of mutant and wild-type parasites, growing under bradyzoite conditions, revealed a hierarchy of developmentally regulated genes, including many bradyzoite-induced genes whose transcripts were reduced in all mutants. A set of non-developmentally regulated genes whose transcripts were less abundant in Tbd- mutants were also identified. These may represent genes that mediate downstream effects and/or whose expression is dependent on the same transcription factors as the bradyzoite-induced set. Using these data, we have generated a model of transcription regulation during bradyzoite development in T. gondii. Our approach shows the utility of this system as a model to study developmental biology in single-celled eukaryotes including protozoa and fungi. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. User Defined
2005-08-13 | E-GEOD-3117 | biostudies-arrayexpress
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:Toxoplasma gondii is an intracellular parasitic protozoan that poses a significant risk to pregnant women and immunocompromised individuals. T. gondii tachyzoites duplicate rapidly in host cells during acute infection through endodyogeny. This highly regulated division process is accompanied by complex gene regulation networks. TgAP2XII-9 is a cyclical transcription factor, but its specific role in the parasite cell cycle is not fully understood. Here, we demonstrate that TgAP2XII-9 is identified as a nuclear transcription factor and is dominantly expressed during the S/M phase of the tachyzoite cell cycle. CUT&Tag results indicate that TgAP2XII-9 targets key genes for the moving junction machinery (RON2, 4, 8) and daughter cell inner membrane complex (IMC). TgAP2XII-9 deficiency resulted in a significant downregulation of rhoptry proteins and rhoptry neck proteins, leading to a severe defect in the invasion and egress efficiency of tachyzoites. Additionally, the loss of TgAP2XII-9 correlated with a substantial downregulation of multiple IMC and apicoplast proteins, leading to disorders of daughter bud formation and apicoplast inheritance, and further contributing to the inability of cell division and intracellular proliferation. Our study reveals that TgAP2XII-9 acts as a critical S/M-phase regulator that orchestrates the endodyogeny and apicoplast division in T. gondii tachyzoite. This study contributes to a broader understanding of the complexity of the parasite’s cell cycle and its key regulators.
2024-05-05 | GSE266204 | GEO
Project description:Developmental switching in Toxoplasma gondii, from the virulent tachyzoite to the relatively quiescent bradyzoite stage, is responsible for disease propagation and reactivation. We have generated tachyzoite to bradyzoite differentiation (Tbd-) mutants in T. gondii and used these in combination with a cDNA microarray to identify developmental pathways in bradyzoite formation. Four independently generated Tbd- mutants were analysed and had defects in bradyzoite development in response to multiple bradyzoite-inducing conditions, a stable phenotype after in vivo passages and a markedly reduced brain cyst burden in a murine model of chronic infection. Transcriptional profiles of mutant and wild-type parasites, growing under bradyzoite conditions, revealed a hierarchy of developmentally regulated genes, including many bradyzoite-induced genes whose transcripts were reduced in all mutants. A set of non-developmentally regulated genes whose transcripts were less abundant in Tbd- mutants were also identified. These may represent genes that mediate downstream effects and/or whose expression is dependent on the same transcription factors as the bradyzoite-induced set. Using these data, we have generated a model of transcription regulation during bradyzoite development in T. gondii. Our approach shows the utility of this system as a model to study developmental biology in single-celled eukaryotes including protozoa and fungi.
2005-07-21 | E-SMDB-1404 | biostudies-arrayexpress