Heterochromatin protein 1 secures survival and transmission of malaria parasites
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ABSTRACT:
ORGANISM(S): Plasmodium falciparum Plasmodium falciparum 3D7
PROVIDER: GSE53176 | GEO | 2014/07/09
SECONDARY ACCESSION(S): PRJNA231046
REPOSITORIES: GEO
Similar Datasets
Project description:The malaria parasite Plasmodium falciparum relies on clonally variant gene expression in order to escape immune recognition and secure continuous proliferation during blood stage infection. Here, we studied the role of heterochromatin protein 1 (HP1), an evolutionary conserved regulator of heritable gene silencing, in the biology of P. falciparum blood stage parasites. We demonstrate that conditional PfHP1 depletion de-represses hundreds of heterochromatic virulence genes and disrupts the elusive mechanism underlying mutually exclusive expression and antigenic variation of PfEMP1. Intriguingly, we also discovered that the PfHP1-dependent regulation of an ApiAP2 transcription factor controls the switch from asexual parasite proliferation to sexual differentiation. This uncovers the first mechanistic insight into the unknown pathway triggering gametocyte conversion and establishes a new concept of HP1-dependent cell fate decision in unicellular eukaryotes. P. falciparum 3D7 parasites expressing endogenous PfHP1-GFP-DD were grown in presence of 4nM WR/625nM Shield-1 (3D7/HP1ON) or 4nM WR (3D7/HP1OFF). RNA extracted from these samples at eleven consecutive time points each was processed for microarray analysis.
2014-07-09 | E-GEOD-53176 | biostudies-arrayexpress
Project description:Epigenetic processes are the main conductors of phenotypic variation in eukaryotes. The malaria parasite Plasmodium falciparum employs antigenic variation of the major surface antigen PfEMP1, encoded by 60 var genes, to evade acquired immune responses. PfEMP1 also mediates sequestration of infected erythrocytes in the microvasculature, which is directly linked to severe malaria outcomes. Antigenic variation of PfEMP1 occurs through in situ switches in mono-allelic var gene transcription, which is PfSIR2-dependent and associated with the presence of repressive H3K9me3 marks at silenced loci. Here, we show that the P. falciparum ortholog of heterochromatin protein 1 (PfHP1) binds to H3K9me3 and constitutes a major component of heterochromatin in perinuclear chromosome end clusters. High-resolution genome-wide chromatin immuno-precipitation demonstrates the striking association of PfHP1 with non-syntenic virulence gene arrays in subtelomeric and chromosome-internal islands. These include not only var genes but the majority of P. falciparum lineage-specific gene families coding for exported proteins involved in host-parasite interactions. Over-expression of PfHP1 resulted in decreased expression of a small number of (virulance) genes and indicated the presence of well-defined heterochromatic boundaries.. In summary, we uncover an unprecedented function of HP1 as a mayor regulator of virulence gene silencing and phenotypic variation, which will be instrumental for our understanding of this widely used survival strategy of unicellular pathogens. one experimental sample
2010-05-06 | E-GEOD-17029 | biostudies-arrayexpress
Project description:Epigenetic processes are the main conductors of phenotypic variation in eukaryotes. The malaria parasite Plasmodium falciparum employs antigenic variation of the major surface antigen PfEMP1, encoded by 60 var genes, to evade acquired immune responses. PfEMP1 also mediates sequestration of infected erythrocytes in the microvasculature, which is directly linked to severe malaria outcomes. Antigenic variation of PfEMP1 occurs through in situ switches in mono-allelic var gene transcription, which is PfSIR2-dependent and associated with the presence of repressive H3K9me3 marks at silenced loci. Here, we show that the P. falciparum ortholog of heterochromatin protein 1 (PfHP1) binds to H3K9me3 and constitutes a major component of heterochromatin in perinuclear chromosome end clusters. High-resolution genome-wide chromatin immuno-precipitation demonstrates the striking association of PfHP1 with non-syntenic virulence gene arrays in subtelomeric and chromosome-internal islands. These include not only var genes but the majority of P. falciparum lineage-specific gene families coding for exported proteins involved in host-parasite interactions. Over-expression of PfHP1 resulted in decreased expression of a small number of (virulance) genes and indicated the presence of well-defined heterochromatic boundaries.. In summary, we uncover an unprecedented function of HP1 as a mayor regulator of virulence gene silencing and phenotypic variation, which will be instrumental for our understanding of this widely used survival strategy of unicellular pathogens.
2009-09-03 | GSE17029 | GEO
Project description:Differentiation from asexual blood stages to sexual gametocytes is required for transmission of malaria parasites from the human to the mosquito host. Preventing gametocyte commitment and development would block parasite transmission, but the underlying molecular mechanisms behind these processes remain poorly understood. Here, we report that the ApiAP2 transcription factor, PfAP2-G2 (PF3D7_1408200) plays a critical role in the maturation of Plasmodium falciparum gametocytes. PfAP2-G2 binds to the promoters of a wide array of genes that are expressed at many stages of the parasite life cycle. Interestingly, we also find binding of PfAP2-G2 within the gene body of almost 3000 genes, which strongly correlates with the location of H3K36me3 and several other histone modifications as well as Heterochromatin Protein 1 (HP1), suggesting that occupancy of PfAP2-G2 in gene bodies may serve as an alternative regulatory mechanism. Disruption of pfap2-g2 does not impact asexual development, parasite multiplication rate, or commitment to sexual development but the majority of sexual parasites are unable to mature beyond stage III gametocytes. The absence of pfap2-g2 leads to overexpression of 28% of the genes bound by PfAP2-G2 and none of the PfAP2-g2 bound are downregulated, suggesting that it is a repressor. We also find that PfAP2-G2 interacts with chromatin remodeling proteins, a microrchidia (MORC) protein, and another ApiAP2 protein (PF3D7_1139300). Overall our data demonstrate that PfAP2-G2 is an important transcription factor that establishes an essential gametocyte maturation program in association with other chromatin-related proteins.
2021-02-01 | GSE160924 | GEO
Project description:Differentiation from asexual blood stages to sexual gametocytes is required for transmission of malaria parasites from the human to the mosquito host. Preventing gametocyte commitment and development would block parasite transmission, but the underlying molecular mechanisms behind these processes remain poorly understood. Here, we report that the ApiAP2 transcription factor, PfAP2-G2 (PF3D7_1408200) plays a critical role in the maturation of Plasmodium falciparum gametocytes. PfAP2-G2 binds to the promoters of a wide array of genes that are expressed at many stages of the parasite life cycle. Interestingly, we also find binding of PfAP2-G2 within the gene body of almost 3000 genes, which strongly correlates with the location of H3K36me3 and several other histone modifications as well as Heterochromatin Protein 1 (HP1), suggesting that occupancy of PfAP2-G2 in gene bodies may serve as an alternative regulatory mechanism. Disruption of pfap2-g2 does not impact asexual development, parasite multiplication rate, or commitment to sexual development but the majority of sexual parasites are unable to mature beyond stage III gametocytes. The absence of pfap2-g2 leads to overexpression of 28% of the genes bound by PfAP2-G2 and none of the PfAP2-g2 bound are downregulated, suggesting that it is a repressor. We also find that PfAP2-G2 interacts with chromatin remodeling proteins, a microrchidia (MORC) protein, and another ApiAP2 protein (PF3D7_1139300). Overall our data demonstrate that PfAP2-G2 is an important transcription factor that establishes an essential gametocyte maturation program in association with other chromatin-related proteins.
2021-02-01 | GSE160923 | GEO
Project description:Differentiation from asexual blood stages to sexual gametocytes is required for transmission of malaria parasites from the human host to mosquitos, where sexual fertilization occurs to complete the lifecycle. Although preventing gametocyte development would block parasite transmission, the molecular mechanisms underlying sexual commitment and gametocyte maturation are still relatively unknown. Previous studies identified an ApiAP2 protein, AP2-G2, which plays a critical role in gametocyte maturation in rodent malaria parasite Plasmodium berghei by acting as the repressor of asexual stage genes in gametocytes. In this work we characterize the P. falciparum orthologue (PF3D7_1408200) of PbAP2-G2 and report that it plays a critical role in maturation of gametocytes. Disruption of pfap2-g2 did not obstruct commitment to sexual development but the majority of parasites were unable to develop normally beyond stage III gametocytes. In asexual stages PfAP2-G2 binds to the promoters of wide variety of genes expressed in diverse range of parasite’s life cycle stages including gametocytes, mosquito lifecycle stages early ring stage genes and genes encoding for proteins involved in egress and invasion. Surprisingly, we also identify binding of PfAP2-G2 in the gene body of almost 3000 genes. We could also show that PfAP2-G2 interacts with chromatin remodeling proteins and another ApiAP2 protein (PF3D7_1139300) whose motif is also overrepresented in the ChIP-seq data. Overall this work suggests that PfAP2-G2 is a transcriptional regulator that regulates genes possibly by recruiting additional transcription factors and chromatin remodeling machinery and plays a critical role in the development of malaria parasites as they transition from the asexual stage to gametocytes.
2021-02-16 | GSE157753 | GEO
Project description:Investigation of whole genome gene expression level changes in Plasmodium falciparum 3D7 delta-PfPuf2 mutant, compared to the wild-type strain 3D7. The mutation engineered into this strain render tanslational control. The mutants analyzed in this study are further described in Miao J, Li J, Fan Q, Li X, Li X, Cui L.2010. The Puf-family RNA-binding protein PfPuf2 regulates sexual development and sex differentiation in the malaria parasite Plasmodium falciparum. J Cell Sci. 123(7):1039-49 (PMID 20197405). A 12 chip study using total RNA recovered from six separate wild-type cultures of Plasmodium falciparum 3D7 at gametocyte stage III (three cultures) and stage V (three cultures) and six separate cultures of dalta PfPuf2 mutant at gametocyte stage III (three cultures) and stage V (three cultures). Each chip measures the expression level of 5,367 genes from Plasmodium falciparum 3D7 with 45-60 mer probes with two replicates on final array of 71618 probes.
2012-07-05 | E-GEOD-39124 | biostudies-arrayexpress
Project description:During intra-erythrocytic development, late asexually replicating Plasmodium falciparum parasites sequester from peripheral circulation. This facilitates chronic infection and is linked to severe disease and organ-specific pathology including cerebral and placental malaria. Immature gametocytes M-bM-^@M-^S sexual stage precursor cells M-bM-^@M-^S likewise disappear from circulation. Recent work has demonstrated that these sexual stage parasites are located in the hematopoietic system of the bone marrow before mature gametocytes are released into the blood stream to facilitate mosquito transmission. However, as sequestration occurs only in vivo and not during in vitro culture, the mechanisms by which it is regulated and enacted (particularly by the gametocyte stage) remain poorly understood. We generated the most comprehensive P. falciparum functional gene network to date by integrating global transcriptional data from a large set of asexual and sexual in vitro samples, patient-derived in vivo samples, and a new set of in vitro samples profiling sexual commitment. We defined more than 250 functional modules (clusters) of genes that are co-expressed primarily during the intra-erythrocytic parasite cycle, including 35 during sexual commitment and gametocyte development. Comparing the in vivo and in vitro datasets allowed us, for the first time, to map the time point of asexual parasite sequestration in patients to 22 hours post invasion, confirming previous in vitro observations on the dynamics of host cell modification and cytoadherence. Moreover, we were able to define the properties of gametocyte sequestration, demonstrating the presence of two circulating gametocyte populations: gametocyte rings between 0 and ~30 hours post invasion and mature gametocytes after around 7 days post invasion. We used 164/TdTom, a transgenic parasite line expressing a red fluorescent protein reporter under a gametocyte-specific promoter to generate schizont samples. Schizonts were subsequently isolated from both the fluorescent and non-fluorescent population by FACS and prepared for microarray analysis. Two biological replicates were produced for both the fluorescent and the non-fluorescent samples.
2015-01-13 | E-GEOD-64887 | biostudies-arrayexpress
Project description:A genome-wide expression analysis was undertaken to identify novel genes specifically activated from early stages of gametocytogenesis in Plasmodium falciparum. A comparative analysis was conducted on sexually induced cultures of reference parasite clone 3D7 and its gametocyteless derivative clone F12. Competitive hybridisations on long-oligomer microarrays representing 4488 P. falciparum genes identified a remarkably small number of transcripts differentially produced in the two clones. Upregulation of the mRNAs for the early gametocyte markers Pfs16 and Pfg27 was however readily detected in 3D7, and such genes were used as reference transcripts in a comparative time course analysis of 3D7 and F12 parasites between 30 and 40 h post-invasion in cultures induced to enter gametocytogenesis. One hundred and seventeen genes had expression profiles which correlated to those of pfs16 and pfg27, and Northern blot analysis and published proteomic data identified those whose expression was gametocyte-specific. Immunofluorescence analysis with antibodies against two of these gene products identified two novel parasite membrane associated, sexual stage-specific proteins. One was produced from stage I gametocytes and the second showed peak production in stage II gametocytes. The two proteins were named Pfpeg-3 and Pfpeg-4, for P. falciparum proteins of early gametocytes.
2007-09-26 | E-MEXP-1250 | biostudies-arrayexpress
Project description:In this study we have investigated PfAP2-HC (PF3D7_1456000), a protein that was identified by co-immunoprecipitation with PfHP1 coupled with liquid chromatography-tandem mass spectrometry. PfAP2-HC belongs to the ApiAP2 family, the main transcription factor family in Apicomplexan parasites. We have confirmed that AP2-HC colocalises with HP1 with the use of immunofluorescence assays and chromatin immunoprecipitation-sequencing. We show that PfAP2-HC is not required for heterochromatin maintenance and inheritance with the use of PfAP2-HC Kock out and knockdown. We show with transcriptome-wide microarray time course analysis that PfAP2-HC does not act as a transcription factor in blood stage parasites. We demonstrate that the AP2 domain is dispensable for heterochromatin targeting by introducing a premature stop codon before the AP2 domain. We show that PfAP2-HC binding to heterochromatin dependents on PfHP1. and PfAP2-HC is likely not involved in de novo heterochromatin formation
2020-11-04 | GSE154840 | GEO