H2A.Z Demarcates Intergenic Regions of the Plasmodium falciparum Epigenome That Are Dynamically Marked by H3K9ac and H3K4me3
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: PRJNA133177PRJNA130731PRJNA133173PRJNA133167
ORGANISM(S): Plasmodium falciparum 3D7
PROVIDER: GSE23787 | GEO | 2010/10/28
SECONDARY ACCESSION(S): PRJNA130731
REPOSITORIES: GEO
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Project description:Epigenetic regulatory mechanisms and their enzymes are promising targets for malaria therapeutic intervention; however, the epigenetic component of gene expression in P. falciparum is poorly understood. Dynamic or stable association of epigenetic marks with genomic features provides important clues about their function and helps to understand how histone variants/modifications are used for indexing the Plasmodium epigenome. We describe a novel, linear amplification method for next-generation sequencing (NGS) that allows unbiased analysis of the extremely AT-rich Plasmodium genome. We used this method for high resolution, genome-wide analysis of a histone H2A variant, H2A.Z and two histone H3 marks throughout parasite intraerythrocytic development. Unlike in other organisms, H2A.Z is a constant, ubiquitous feature of euchromatic intergenic regions throughout the intraerythrocytic cycle. The almost perfect colocalisation of H2A.Z with H3K9ac and H3K4me3 suggests that these marks are preferentially deposited on H2A.Z-containing nucleosomes. By performing RNA-seq on 8 time-points, we show that acetylation of H3K9 at promoter regions correlates very well with the transcriptional status whereas H3K4me3 appears to have stage-specific regulation, being low at early stages, peaking at trophozoite stage, but does not closely follow changes in gene expression. Our improved NGS library preparation procedure provides a foundation to exploit the malaria epigenome in detail. Furthermore, our findings place H2A.Z at the cradle of P. falciparum epigenetic regulation by stably defining intergenic regions and providing a platform for dynamic assembly of epigenetic and other transcription related complexes.
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Project description:H2A.Z Demarcates Intergenic Regions of the Plasmodium falciparum Epigenome That Are Dynamically Marked by H3K9ac and H3K4me3
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Project description:Non-coding (nc) RNAs are involved both in recruitment of vertebrate Polycomb (PcG) proteins to chromatin, and in activation of PcG target genes. Here we investigate dynamic changes in the relationship between ncRNA transcription and recruitment of PcG proteins to chromatin during differentiation. Profiling of purified cell populations from different stages of a defined murine in vitro neural differentiation system shows that over 50% of regulated intergenic non-coding transcripts precisely correspond to PcG target sites. We designate these PcG recruiting elements as Transcribed Intergenic Polycomb (TIP) sites. The relationship between TIP transcription and PcG recruitment switches dynamically during differentiation between different states, in which transcription and PcG recruitment exclude each other, or in which both are present. Reporter assays show that transcribed TIP sites can repress a flanking gene. Knockdown experiments demonstrate that TIP ncRNAs are themselves required for repression of target genes both in cis and in trans. We propose that TIP transcription may ensure coordinated regulation of gene networks via dynamic switching and recruitment of PcG proteins both in cis and in trans during lineage commitment.
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Project description:Histone modification profiles are predictive of gene expression and most of the knowledge gained is acquired through studies done in higher eukaryotes. However, genome-wide studies involving Plasmodium falciparum, the causative agent of malaria, have been rather few, at lower resolution (mostly using ChIP-on-chip), and covering limited number of histone modifications. In our recent study [1], we have performed extensive genome-wide analyses of multiple histone modifications including the active (H3K4me2, H3K4me3, H3K9ac, H3K14ac, H3K27ac and H4ac), inactive (H3K9me3 and H3K27me3), elongation (H3K79me3) and regulatory element (H3K4me1) in a stage-specific manner. Furthermore, we used a ligation-based method suitable for sequencing homopolymeric stretches as seen in P. falciparum for next-generation sequencing library amplification [2], enabling highly quantitative analysis of the extremely AT-rich P. falciparum genome. Our recently published study suggests that transcription regulation by virtue of poised chromatin and differential histone modifications is unique to P. falciparum [1]. Here we describe the experiments, quality controls and chromatin immunoprecipitation-sequencing data analysis of our associated study published in Epigenetics and Chromatin [1]. Stage-specific ChIP-sequencing data for histone modifications is submitted to Gene Expression Omnibus (GEO) database under the accession number GSE63369.
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Project description:Epigenome profiling has led to the paradigm that promoters of active genes are decorated with H3K4me3 and H3K9ac marks. To explore the epigenome of Plasmodium falciparum asexual stages, we performed MS analysis of histone modifications and found a general preponderance of H3/H4 acetylation and H3K4me3. ChIP-on-chip profiling of H3, H3K4me3, H3K9me3, and H3K9ac from asynchronous parasites revealed an extensively euchromatic epigenome with heterochromatin restricted to variant surface antigen gene families (VSA) and a number of genes hitherto unlinked to VSA. Remarkably, the vast majority of the genome shows an unexpected pattern of enrichment of H3K4me3 and H3K9ac. Analysis of synchronized parasites revealed significant developmental stage specificity of the epigenome. In rings, H3K4me3 and H3K9ac are homogenous across the genes marking active and inactive genes equally, whereas in schizonts, they are enriched at the 5' end of active genes. This study reveals an unforeseen and unique plasticity in the use of the epigenetic marks and implies the presence of distinct epigenetic pathways in gene silencing/activation throughout the erythrocytic cycle.
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Project description:Control strategies implemented a decade ago led to a marked reduction in the prevalence of malaria in many countries. In Dienga, southeastern Gabon, the prevalence of microscopic P. falciparum infection was 7% in 2003, close to the pre-elimination threshold of 5%. The aim of this work was to determine the prevalence of P. falciparum infection in the same community a decade later. A cohort of 370 individuals aged from 3 to 85 years living in Dienga was investigated for P. falciparum infection; during six passages (P) in 15-month period. Demographic data were collected, along with behaviors and attitudes towards malaria. Plasmodium infection was diagnosed by microscopy (ME), followed by PCR to detect submicroscopic infection. The prevalence of P. falciparum infection in P1, P2, P3, P4, P5 and P6 was respectively 43.5% (25.1% ME+, 18.4% PCR+); 40.9% (27.0% ME+, 13.9% PCR+), 52.7% (26.1% ME+, 26.6% PCR+); 34.1% (14.1% ME+, 20% PCR+), 57.7% (25.4.% ME+, 32.3% PCR+); and 46.2% (21.4% ME+, 24.8% PCR+) with an overall average of 45.9% (95%CI [37.0-54.7], 23.2% ME+ and 22.7% PCR+). P4 and P5 prevalences were statically different throughout the six passages. Microscopic prevalence was significantly higher than that observed ten years ago (23% [n = 370] vs 7% [n = 323], p < 0.001). Asymptomatic infections were the most frequent (96%). Gametocytes were detected in levels ranging from 5.9% to 13.9%. Insecticide-treated nets, indoor residual insecticides, and self-medication were used by respectively 33.2% (95%CI [29.0-37.4]), 17.7% (95%CI [15.5-19.9]) and 12.1% (95%CI [10.6-13.6]) of the study population. A near-threefold increase in P. falciparum infection has been observed in a rural area of southeastern Gabon during a 10-year period. Most infections were asymptomatic, but these subjects likely represent a parasite reservoir. These findings call for urgent reinforcement of preventive measures.
| S-EPMC4881998 | biostudies-literature
Project description:Chromatin structure is a basal epigenetic mechanism that determines cellular fate by organizing the dynamic gene expression during the cell development and proliferation. The nuclear members of the evolutionarily conserved actin-related protein (ARPs) superfamily are major components of nucleosome remodelingcomplexes in the nucleus. In the human malaria parasites, Plasmodium falciparum, comparative genome analysis reveals that two canonical actins and three orthologues of ARPs including PfArp1, PfArp4, and PfArp6 are encoded in the genome of this parasite. However, little is known about the biological functions of the two nuclear PfArp4 and PfArp6 proteins. Here, by Pfarp4 gene knockdown and comparative transcriptome analysis, we uncovered that PfArp4 correlated positively with the dynamic expression of eukaryotic genes. Genome-wide distribution analysis by ChIP-seq revealed that PfArp4 protein colocalized with the histone 2A variant H2A.Z and euchromatic marker H3K9ac in the intergenic regions. Inducible downregulation of PfArp4 resulted in the depletion of H2A.Z and lower H3K9ac level at the upstream regions of eukaryotic genes, thereby repressing the transcriptional abundances. Moreover, we found a significant enrichment of PfArp4 at the flanking sites of centromeres, which likely shapes the H2A.Z-enriched centromeric chromatin microenvironment as a boundary marker. PfArp4 depletion triggered loss of H2A.Z at the entire centromere regions, and arrested the blood-stage development probably through interference with the schizogony process. Finally, PfArp6 was detected as an interactor of PfArp4 in the nucleus. Taken together, our finding indicates that the nuclear PfArp4/6regulates the cell cycles through controlling H2A.Z deposition and centromere biology, which will contribute to understanding the complex epigenetic regulation of gene expression and development of the malaria parasites.
2020-06-24 | GSE143900 | GEO
Project description:Histone modifications (H3K9me3, H3K9Ac, H3K4me3, H4K20me3) across Plasmodium falciparum genome in 3D7 wt and 3D7 Sir2 KO
2009-02-24 | E-MEXP-1806 | biostudies-arrayexpress
Project description:Histone variants are key components of the epigenetic code and evolved to perform specific functions in transcriptional regulation, DNA repair, chromosome segregation and other fundamental processes. H2B.Z is a rare, apicomplexan-specific variant of histone H2B. Here we show that in Plasmodium falciparum H2B.Z localises to euchromatic intergenic regions throughout intraerythrocytic development and together with H2A.Z forms a double-variant nucleosomes subtype. These nucleosomes are enriched in promoters over 3’ intergenic regions and their occupancy generally correlates with the strength of the promoter, but not with its temporal activity. Remarkably, H2B.Z occupancy levels exhibit a clear correlation with the base-composition of the underlying DNA, raising the intriguing possibility that the extreme AT-content of the intergenic regions within the Plasmodium genome might be instructive for histone variant deposition. In summary, our data shows that the H2A.Z/H2B.Z double-variant nucleosome demarcates putative regulatory regions of the P. falciparum epigenome and likely provides a scaffold for dynamic regulation of gene expression in this deadly human pathogen. Genome-wide localization of H2B.Z has been studied at three stages of intraerythrocytic development by Illumina sequencing of chromatin-immunoprecipitated and input DNA.
2013-03-05 | E-GEOD-39702 | biostudies-arrayexpress
Project description:Histone variants are key components of the epigenetic code and evolved to perform specific functions in transcriptional regulation, DNA repair, chromosome segregation and other fundamental processes. H2B.Z is a rare, apicomplexan-specific variant of histone H2B. Here we show that in Plasmodium falciparum H2B.Z localises to euchromatic intergenic regions throughout intraerythrocytic development and together with H2A.Z forms a double-variant nucleosomes subtype. These nucleosomes are enriched in promoters over 3’ intergenic regions and their occupancy generally correlates with the strength of the promoter, but not with its temporal activity. Remarkably, H2B.Z occupancy levels exhibit a clear correlation with the base-composition of the underlying DNA, raising the intriguing possibility that the extreme AT-content of the intergenic regions within the Plasmodium genome might be instructive for histone variant deposition. In summary, our data shows that the H2A.Z/H2B.Z double-variant nucleosome demarcates putative regulatory regions of the P. falciparum epigenome and likely provides a scaffold for dynamic regulation of gene expression in this deadly human pathogen.
2013-03-05 | GSE39702 | GEO