3D7 PfHda2 Knockdown vs. Wildtype
Ontology highlight
ABSTRACT:
ORGANISM(S): Plasmodium falciparum 3D7 Plasmodium falciparum
PROVIDER: GSE54806 | GEO | 2014/02/11
SECONDARY ACCESSION(S): PRJNA237743
REPOSITORIES: GEO
Similar Datasets
Project description:The asexual forms of the malaria parasite Plasmodium falciparum are uniquely adapted for chronic persistence in human red blood cells, continuously evading the immune system using an epigenetically regulated process. However, parasite survival on a population level also requires transmission of sexual parasite forms to subsequent human hosts. Here, we reveal that the essential nuclear gene, P. falciparum histone deacetylase 2 (PfHda2), silences specific subsets of genes involved in antigenic variation or conversion to sexual stages. Two parallel timecourses resulting in a total of 22 samples (11 wildtype, 11 PfHda2 knockdown) were hybridized against a Cy3-labeled reference pool of 3D7 mixed stage parasites on a two-color array.
2014-02-11 | E-GEOD-54806 | biostudies-arrayexpress
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:Little is known about the role of the three Jumonji C (JmjC) enzymes in Plasmodium falciparum (Pf). Here, we show that JIB-04 and other established inhibitors of mammalian JmjC histone demethylases kill asexual blood stage parasites and are even more potent at blocking gametocyte development and gamete formation. In late stage parasites, JIB-04 increased levels of trimethylated lysine residues on histones, suggesting the inhibition of P. falciparum Jumonji demethylase activity. These epigenetic defects coincide with deregulation of invasion, cell motor, and sexual development gene programs, including gene targets coregulated by the PfAP2-I transcription factor and chromatin-binding factor, PfBDP1. Mechanistically, we demonstrate that PfJmj3 converts 2-oxoglutarate to succinate in an iron-dependent manner consistent with mammalian Jumonji enzymes, and this catalytic activity is inhibited by JIB-04 and other Jumonji inhibitors. Our pharmacological studies of Jumonji activity in the malaria parasite provide evidence that inhibition of these enzymatic activities is detrimental to the parasite.
2020-07-12 | GSE117307 | GEO
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.
2014-07-09 | GSE53176 | 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).
2012-07-06 | GSE39124 | 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:This experiment studies the effect of knocking out the transcriptional regulator SIR2 in 3D7 parasites. RNA was harvested from ring-stage parasites at 8 hours post-infection. Keywords = SIR2 Keywords = epigenetic regulation Keywords = antigenic variation Keywords = var Keywords = Plasmodium falciparum Keywords: other
2005-03-08 | GSE2369 | GEO
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for the transcriptional response of control Plasmodium falciparum asexual blood stages not treated with the calcium ionophores, A23187 and ionomycin has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the untreated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
2012-07-14 | E-GEOD-33795 | biostudies-arrayexpress
Project description:Calcium is a universal second messenger molecule which plays a significant role in several biological processes. Presence of calcium sensors (calmodulins) and calcium-dependent protein kinases in Plasmodium species suggests an important role of calcium-dependent signaling pathways in the regulation of cellular processes in the malaria parasites. Evidence for extracellular calcium chelation of the control Plasmodium falciparum asexual blood stages not treated with the calcium ionophore ionomycin and EGTA has been presented here. P. falciparum 3D7 strain was cultured as described by Bozdech Z, Llinas M, Pulliam BL, Wong ED, Zhu J, DeRisi JL: The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 2003, 1(1):E5. Total RNA from each of the time points was isolated and aminoallyl-cDNA was synthesized using reverse transcriptase system (Fermentas). cDNA made from the untreated parasites were labeled with Cy5 (GE-Amersham). A reference pool was made by mixing equal amount of cDNA from the parasites collected at 6 hours interval throughout the 48 hours life cycle and was labeled with Cy3 (GE-Amersham). The samples were then hybridized on a spotted cDNA chip platform comprising 10166 MOEs representing 5363 coding sequences as described in Hu G, Cabrera A, Kono M, Mok S, Chaal BK, Haase S, Engelberg K, Cheemadan S, Spielmann T, Preiser PR, Gilberger TW, Bozdech Z: Transcriptional profiling of growth perturbations of the human malaria parasite Plasmodium falciparum. Nat Biotechnol, 2009. 28(1): p. 91-8. The data was normalized and filtered with the condition, signal intensity>background intensity + 2 SD of background intensity) using NOMAD.
2012-07-14 | E-GEOD-33834 | 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