Identification of genome-wide binding sites of Plasmodium falciparum GCN5-acetyltransferase
Ontology highlight
ABSTRACT:
ORGANISM(S): Plasmodium falciparum 3D7
PROVIDER: GSE142803 | GEO | 2020/01/01
REPOSITORIES: GEO
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Project description:We identified unconventional histone lysine trimethylation mark in the nucleosome core at H3K64 position in human malaria parasite Plasmodium falciparum. Global ChIP analysis was performed using anti-H3K64me3 specific antibody for three major blood stages, i.e. ring, trophozoite and schizont stages to identify the genomic position of the H3K64me3. The sheared chromatin was prepared from highly synchronous P. falciparum culture and subjected for ChIP followed by library preparation from the ChIP DNA and were subjected to sequencing using the HiSeq Illumina platform. H3K64me3 binding sites were determined after sequence alignment and normalization with input sequence. Interestingly, there was a significant reduction in the number of peaks on different chromosomes during multinucleated schizont stage as compared to ring and trophozoite stage. Collectively, this is first study to show that H3K64me3 function as repressor methyl mark during ring and trophozoite stages to regulate the expression of schizont specific export family of proteins in P. falciparum.
2020-07-18 | GSE154651 | GEO
Project description:The parasite Plasmodium falciparum is responsible for severe malaria, which is still one of the major causes of death in developing countries. To provide a new RNA-seq reference dataset for its blood-stage transcriptome according to current guidelines and best practices, we performed a time course experiment with three independent biological replicates of synchronized P. falciparum 3D7 cells, that were cultivated at a haematocrit of 5% in human O+ erythrocytes. RNA-seq samples were taken at 8 developmental stages including young ring stage (8 hpi), late ring stage/early trophozoite (16 hpi), mid-age trophozoite (24 hpi), late trophozoite (32 hpi), early schizont (40 hpi), schizont (44 hpi), late schizont (48 hpi) and purified merozoites (0 hpi). Red blood cell pellets were lysed with Trizol and total RNA was purified using column-based purification (PureLink RNA Kit) including DNase treatment on the column and controlling for absence of genomic DNA contamination using qPCR. Whole blood total RNA samples were depleted of human globin mRNA using magnetic bead isolation technology (GLOBINclear kit). After RNA sample quality control and optimized cDNA libraries preparation for AT-biased genomes for Illumina sequencing, RNA-seq was performed at BGI Genomics (Shenzhen, China) on HiSeq 4000 to generate 100 bp paired-end sequencing reads.
2019-07-02 | E-MTAB-7731 | biostudies-arrayexpress
Project description:Effects of PfAP2-EXP2 knockdown on gene expression at the ring, trophozoite, and schizont stages
2022-02-02 | GSE180436 | GEO
Project description:Background: Epigenetic modifications of histones and regulation of chromatin structure have been implicated in regulation of virulence gene families in P. falciparum. To better understand chromatin-mediated gene regulation, we used a high-density oligonucleotide microarray to map the position and enrichment of nucleosomes across the entire genome of P. falciparum at three time points of the intra-erythrocytic developmental cycle (IDC) in vitro. We used an unmodified histone H4 antibody for chromatin immunoprecipitation of nucleosome-bound DNA. Results: We observed generally low nucleosomal occupancy of intergenic regions and higher occupancy of protein coding regions. In contract to the overall small fluctuation of nucleosomal occupancy in most coding regions throughout the IDC, subtelomeric genes encoding surface proteins such as var and rif, as well as some core chromosomal genes such as transcription factors, showed large changes in chromatin structure. Telomeres harbored a region with the highest nucleosomal occupancy of the genome and also exhibited large changes with higher nucleosomal occupancy at schizont stages. While many of these subtelomeric genes were previously shown to be modified by H3K9 trimethylation, we also identified some housekeeping genes in core chromosome regions that showed extensive changes in chromatin structure but do not contain this modification. tRNA and basal transcription factor genes showed low nucleosomal occupancy at all times, suggesting of an open chromatin structure that might be permissive for constitutively high levels of expression. Generally, nucleosomal occupancy was not correlated with the steady-state mRNA levels. Several var genes were exceptions: the var gene with the highest expression level showed the lowest nucleosomal occupancy, and selection of parasites for var2CSA expression resulted in lower nucleosomal occupancy at the var2CSA locus. We identified nucleosome-free regions in intergenic regions that may serve as transcription start sites or transcription factor binding sites. Using the nucleosomal occupancy data as the baseline, we further mapped the genome-wide enrichment of H3K9 acetylation and detected general enrichment of this mark in intergenic regions. Conclusions: These data on nucleosome enrichment changes add to our understanding of the influence of chromatin structure on the regulation of gene expression. Histones are generally enriched in coding regions, and relatively poor in intergenic regions. Histone enrichment patterns allow for identification of new putative gene-coding regions. Most genes do not show correlation between chromatin structure and steady-state mRNA levels, indicating the dominant roles of other regulatory mechanisms. We present a genome-wide nucleosomal occupancy map, which can be used as a reference for future experiments of histone modification mapping. Three ChIP with unmodified histone H4 antibodies were performed on ring, trophozoite and schizont stage synchronized parasites. Only one experiment was performed per time point. H3K9ac antibody ChIP was performed on trophozoite stage cells. All samples were normalized to 3D7 strain genomic DNA hybridizations.
2009-12-01 | E-GEOD-18968 | biostudies-arrayexpress
Project description:Epigenetic mechanisms have been poorly understood in Plasmodium falciparum, the causative agent of malaria. To elucidate stage specific epigenetic regulations in P. falciparum, we performed genome-wide mapping of various histone modifications, nucleosomes and RNA Polymerase II. Our comprehensive analysis suggest that transcription initiation and elongation are distinct in Plasmodium. In this study, by analyzing histone modifications, nucleosome occupancy and RNA Polymerase II (Pol II) at three different IEC developmental stages of Plasmodium; ring, trophozoite and schizont, we tried to unravel the epigenetic mechanism associated with gene regulation.
2015-09-23 | GSE63369 | GEO
Project description:Epigenetic mechanisms have been poorly understood in Plasmodium falciparum, the causative agent of malaria. To elucidate stage specific epigenetic regulations in P. falciparum, we performed genome-wide mapping of various histone modifications, nucleosomes and RNA Polymerase II. Our comprehensive analysis suggest that transcription initiation and elongation are distinct in Plasmodium. In this study, by analyzing histone modifications, nucleosome occupancy and RNA Polymerase II (Pol II) at three different IEC developmental stages of Plasmodium; ring, trophozoite and schizont, we tried to unravel the epigenetic mechanism associated with gene regulation. Examination of H3K27me3, H3K4me3, H3K9me3, H3K14ac, H3K4me1, H3K79me3, H3K27ac, H3K4me2, H3K9ac, H4ac, RNA Pol II and Histone H3 at three different stages of Plasmodium falciparum
2015-09-23 | E-GEOD-63369 | biostudies-arrayexpress
Project description:Genome-wide ChIP-sequencing analysis of PfMCM6 was carried out in trophozoite stage parasites using PfMCM6 antibodies. We have observed that PfMCM6 is highly enriched at the exon regions. Moreover, PfMCM6 was also found in promoter-TSS, transcription termination site (TTS), and intergenic regions in minimal proportion. This study shed some light on PfMCM6 binding sites in Plasmodium falciparum genome.
2023-07-29 | GSE224073 | GEO
Project description:Genome-wide occupancy of PfAP2-EXP2 at the schizont stage
2022-02-02 | GSE180437 | GEO
Project description: Not available
| S-EPMC387650 | biostudies-literature
Project description:Abstract of associated publication: Background: During the latter half of the natural 48-hour intraerythrocytic life cycle of human Plasmodium falciparum infection, parasites sequester deep in endothelium tissues, away from the spleen and inaccessible to peripheral blood. These late-stage parasites may cause tissue damage and likely contribute to clinical disease, and a more complete understanding of their biology is needed. Because these life cycle stages are not easily sampled due to deep tissue sequestration, measuring in vivo gene expression of parasites in the trophozoite and schizont stages has been a challenge. Methods: We developed a custom nCounter® gene expression platform, and used this platform to measure malaria parasite gene expression profiles in vitro and in vivo. We also used imputation to generate global transcriptional profiles, and assessed differential gene expression between parasites growing in vitro and those recovered from malaria-infected patient tissues collected at autopsy. Results: We demonstrate, for the first time, global transcriptional expression profiles from in vivo malaria parasites sequestered in human tissues. We found that parasite physiology can be correlated with in vitro data from an existing life cycle data set, and that parasites in sequestered tissues show an expected schizont-like transcriptional profile, which is conserved across tissues from the same patient. Imputation based on 60 landmark genes generated global transcriptional profiles that were highly correlated with genome-wide expression patterns from the same sample measured by microarray. Finally, differential expression revealed a limited set of in vivo upregulated transcripts, which may indicate unique parasite genes involved in human clinical infections. Conclusions: Our study highlights the utility of a custom nCounter® P. falciparum probe set, validation of imputation within Plasmodium species, and documentation of in vivo schizont-stage expression patterns from human tissues.
2014-11-15 | GSE63260 | GEO