scholarly journals Metabolomics profiling reveals new aspects of dolichol biosynthesis in Plasmodium falciparum

2019 ◽  
Author(s):  
Flavia M. Zimbres ◽  
Ana Lisa Valenciano ◽  
Emilio F. Merino ◽  
Anat Florentin ◽  
Nicole R. Holderman ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
De Novo ◽  
Isotopic Labeling ◽  
Eukaryotic Cells ◽  
Linear Polymers ◽  
Biological Functions ◽  
Predominant Species ◽  
Conditional Mutant ◽  
Asexual Cycle

The cis-polyisoprenoid lipids namely polyprenols, dolichols and their derivatives are linear polymers of several isoprene units. In eukaryotes, polyprenols and dolichols are synthesized as a mixture of four or more homologues of different length with one or two predominant species with sizes varying among organisms. Polyprenols have been hardly detectable in eukaryotic cells under normal conditions with the exception of plants and sporulating yeast. Our metabolomics studies revealed that cis-polyisoprenoids are more prevalent and diverse in the parasite Plasmodium falciparum than previously postulated as we uncovered active de novo biosynthesis and substantial levels of accumulation of polyprenols and dolichols of 15 to 19 isoprene units. A distinctive polyprenol and dolichol profile both within the intraerythrocytic asexual cycle and between asexual and gametocyte stages was also observed suggesting that cis-polyisoprenoid biosynthesis changes throughout parasite’s development. In addition, we confirmed the presence of an active cis-prenyltransferase (PfCPT) and that dolichol biosynthesis occurs via reduction of the polyprenol to dolichol by an active polyprenol reductase (PfPPRD) in the malaria parasite. Isotopic labeling and metabolomic analyses of a conditional mutant of PfCPT or PfPPRD suggest that polyprenols may be able to substitute dolichols in their biological functions when dolichol synthesis is impaired in Plasmodium.

scholarly journals Disruption of Plasmodium falciparum histidine-rich protein II may affect haem metabolism in the blood stage

2020 ◽  
Author(s):  
Yingchao Yang ◽  
Tongke Tang ◽  
Bo Feng ◽  
Shanshan Li ◽  
Nan Hou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
De Novo ◽  
Transcript Level ◽  
Blood Stage ◽  
Gene Transcript ◽  
Parasite Line ◽  
Genes Encoding ◽  
Comparison Groups ◽  
Transgenic Parasites

Abstract Background: Haem is a key metabolic factor in the life cycle of the malaria parasite. In the blood stage, the parasite acquires host haemoglobin to generate amino acids for protein synthesis and the by-product haem for metabolic use. The malaria parasite can also synthesize haem de novo by itself. Plasmodium falciparum-specific histidine-rich protein 2 (PfHRP2) has a haem-binding site to mediate the formation of haemozoin, a biocrystallized form of haem aggregates. Notably, the gene regulates the mechanism of haemoglobin-derived haem metabolism and the de novo haem biosynthetic pathway in the Pfhrp2-disrupted parasite line during the intraerythrocytic stages. Methods: The CRISPR/Cas9 system was used to disrupt the gene locus of Pfhrp2. DNA was extracted from the transgenic parasite, and polymerase chain reaction (PCR), Southern blotting and Western blotting were used to confirm the establishment of transgenic parasites. RNA-Seq and comparative transcriptome analysis were performed to identify differences in gene expression between 3D7 and Pfhrp2- 3D7 parasites.Results: Pfhrp2- transgenic parasites were successfully established by the CRISPR/Cas9 system. A total of 964, 1261, 3138, 1064, 2512, and 1778 differentially expressed genes (DEGs) were identified in the six comparison groups, and a total of 373, 520, 1499, 353, 1253, and 742 of the DEGs were upregulated, and 591, 741, 1639, 711, 1259, and 1036 of the DEGs were downregulated, respectively. Five DEGs related to haem metabolism and synthesis were identified in the comparison groups of six time points (0, 8, 16, 24, 32, and 40 h after merozoite invasion). The genes encoding ALAS and FC, related to haem biosynthesis, were found to be significantly upregulated in the comparison groups, and the HO, SPP, and PBGD genes were found to be significantly downregulated. No GO terms were significantly enriched in haem-related processes (Q value=1).Conclusion: Our data revealed changes in the transcriptome expression profile of the Pfhrp2-3D7 parasite during the intraerythrocytic stages. The above findings provide insight at the gene transcript level for further research and development of anti-malaria drugs.

scholarly journals Disruption of Plasmodium falciparum histidine-rich protein 2 may affect haem metabolism in the blood stage

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Yingchao Yang ◽  
Tongke Tang ◽  
Bo Feng ◽  
Shanshan Li ◽  
Nan Hou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
De Novo ◽  
Aminolevulinic Acid ◽  
Transcript Level ◽  
Blood Stage ◽  
Gene Transcript ◽  
Parasite Line ◽  
Comparison Groups ◽  
Transgenic Parasites

Abstract Background Haem is a key metabolic factor in the life cycle of the malaria parasite. In the blood stage, the parasite acquires host haemoglobin to generate amino acids for protein synthesis and the by-product haem for metabolic use. The malaria parasite can also synthesize haem de novo on its own. Plasmodium falciparum-specific histidine-rich protein 2 (PfHRP2) has a haem-binding site to mediate the formation of haemozoin, a biocrystallized form of haem aggregates. Notably, the gene regulates the mechanism of haemoglobin-derived haem metabolism and the de novo haem biosynthetic pathway in the Pfhrp2-disrupted parasite line during the intraerythrocytic stages. Methods The CRISPR/Cas9 system was used to disrupt the gene locus of Pfhrp2. DNA was extracted from the transgenic parasite, and PCR, Southern blotting and Western blotting were used to confirm the establishment of transgenic parasites. RNA-sequencing and comparative transcriptome analysis were performed to identify differences in gene expression between 3D7 and Pfhrp2--3D7 parasites. Results Pfhrp2- transgenic parasites were successfully established by the CRISPR/Cas9 system. A total of 964, 1261, 3138, 1064, 2512 and 1778 differentially expressed genes (DEGs) were identified in the six comparison groups, respectively, with 373, 520, 1499, 353, 1253 and 742 of these DEGs upregulated and 591, 741, 1639, 711, 1259 and 1036 of them downregulated, respectively. Five DEGs related to haem metabolism and synthesis were identified in the comparison groups at six time points (0, 8, 16, 24, 32, and 40 h after merozoite invasion). The genes encoding delta-aminolevulinic acid synthetase and ferrochelatase, both related to haem biosynthesis, were found to be significantly upregulated in the comparison groups, and those encoding haem oxygenase, stromal-processing peptidase and porphobilinogen deaminase were found to be significantly downregulated. No GO terms were significantly enriched in haem-related processes (Q value = 1). Conclusion Our data revealed changes in the transcriptome expression profile of the Pfhrp2--3D7 parasite during the intraerythrocytic stages. The findings provide insight at the gene transcript level that will facilitate further research on and development of anti-malaria drugs.

scholarly journals Prevalence of malaria infection in pregnant women attending Bamalli Nuhu Maternity Specialist Hospital, Kano, Nigeria

2018 ◽  
Vol 11 (1) ◽  
pp. 82-85
Author(s):  
A.I. Yola ◽  
Z Tukur ◽  
A.A. Dantata
Keyword(s):  
Plasmodium Falciparum ◽  
Pregnant Women ◽  
Infection Rate ◽  
Malaria Infection ◽  
Malaria Parasite ◽  
Plasmodium Ovale ◽  
Blood Samples ◽  
Predominant Species ◽  
Significant Difference ◽  
Made In

This study was conducted to determine the prevalence of malaria parasites in pregnant women attending Bamalli Nuhu Maternity Specialist Hospital Kano. A total of 250 blood samples of pregnant women were tested using field stain method and the parasites were identified using the standard identification keys. Out of which, 180 (72%) were found to be malaria parasite positive. The result of the present study revealed that Plasmodium falciparum had the highest rate of infection with about 68.8% while Plasmodium ovale was found to have an infection rate of 3.2%. The result revealed a highly significant difference within the means levels between the observed species (P. falciparum and P. ovale) (00000.1904***). Based on parity 94 (78.33%) Primigravidae, 61 (72.62%) Secundigravidae and 25 (54.35%) Multigravidae were infected respectively. The result of the findings also reveals that there is a significant difference within the levels of pregnant women Parity (0.01719*). It was concluded that more than half of the pregnant women were infected with malaria infection and P. falciparum was the predominant species then P. ovale. The findings of the study further proved that Primigravidae and Secundigravidae are more susceptible to malaria infection. More effort should be made in order to control malaria infection by providing better clinical management of the disease that includes curative and preventing measures.  Keywords: Prevalence, Parity, Plasmodium, Pregnant Women, Infection rate

scholarly journals Hierarchical transcriptional control regulates Plasmodium falciparum sexual differentiation

2019 ◽  
Author(s):  
Riëtte van Biljon ◽  
Roelof van Wyk ◽  
Heather J. Painter ◽  
Lindsey Orchard ◽  
Janette Reader ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Sexual Differentiation ◽  
Malaria Parasite ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Critical Stage ◽  
Functional Studies ◽  
Transcriptional Dynamics ◽  
Differential Timing ◽  
Asexual Cycle

Abstract Background Malaria pathogenesis relies on sexual gametocyte forms of the malaria parasite to be transmitted between the infected human and the mosquito host but the molecular mechanisms controlling gametocytogenesis remains poorly understood. Here we provide a high-resolution transcriptome of Plasmodium falciparum as it commits to and develops through gametocytogenesis. Results The gametocyte-associated transcriptome is significantly different from that of the asexual parasites, with dynamic gene expression shifts characterizing early, intermediate and late-stage gametocyte development and results in differential timing for sex-specific transcripts. The transcriptional dynamics suggest strict transcriptional control during gametocytogenesis in P. falciparum, which we propose is mediated by putative regulators including epigenetic mechanisms (driving active repression of proliferation-associated processes) and a cascade-like expression of ApiAP2 transcription factors. Conclusions The gametocyte transcriptome serves as the blueprint for sexual differentiation and will be a rich resource for future functional studies on this critical stage of Plasmodium development, as the intraerythrocytic transcriptome has been for our understanding of the asexual cycle.

The human malaria parasite Plasmodium falciparum expresses an atypical N-terminally extended pyrophosphokinase with specificity for thiamine

2006 ◽  
Vol 387 (12) ◽  
pp. 1583-1591 ◽  
Author(s):  
Marie-Luise Eschbach ◽  
Ingrid B. Müller ◽  
Tim-Wolf Gilberger ◽  
Rolf D. Walter ◽  
Carsten Wrenger
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
De Novo ◽  
Mutational Analysis ◽  
Specific Activity ◽  
Active Form ◽  
Vitamin B ◽  
Human Malaria Parasite ◽  
Human Malaria ◽  
Bacteria And Fungi

Abstract Vitamin B1 is an essential cofactor for key enzymes such as 2-oxoglutarate dehydrogenase and pyruvate dehydrogenase. Plants, bacteria and fungi, as well as Plasmodium falciparum, are capable of synthesising vitamin B1 de novo, whereas mammals have to take up this cofactor from their diet. Thiamine, a B1 vitamer, has to be pyrophosphorylated by thiamine pyrophosphokinase (TPK) to the active form. The human malaria parasite P. falciparum expresses an N-terminally extended pyrophosphokinase throughout the entire erythrocytic life cycle, which was analysed by Northern and Western blotting. The recombinant enzyme shows a specific activity of 27 nmol min-1 mg-1 protein and specificity for thiamine with a K m value of 73 μM, while thiamine monophosphate is not accepted. Mutational analysis of the N-terminal extension of the plasmodial TPK showed that it influences thiamine binding as well as metal dependence, which suggests N-terminal participation in the conformation of the active site. Protein sequences of various plasmodial TPKs were analysed for their phylogeny, which classified the Plasmodium TPKs to a group distinct from the mammalian TPKs. To verify the location of the parasite TPK within the cell, immunofluorescence analyses were performed. Co-staining of PfTPK with a GFP marker visualised its cytosolic localisation.

scholarly journals Hierarchical transcriptional control regulates Plasmodium falciparum sexual differentiation

2019 ◽  
Author(s):  
Riëtte van Biljon ◽  
Roelof van Wyk ◽  
Heather J. Painter ◽  
Lindsey Orchard ◽  
Janette Reader ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Sexual Differentiation ◽  
Malaria Parasite ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Critical Stage ◽  
Functional Studies ◽  
Transcriptional Dynamics ◽  
Differential Timing ◽  
Asexual Cycle

Abstract Background: Malaria pathogenesis relies on sexual gametocyte forms of the malaria parasite to be transmitted between the infected human and the mosquito host but the molecular mechanisms controlling gametocytogenesis remains poorly understood. Here we provide a high-resolution transcriptome of Plasmodium falciparum as it commits to and develops through gametocytogenesis. Results : The gametocyte-associated transcriptome is significantly different from that of the asexual parasites, with dynamic gene expression shifts characterizing early, intermediate and late-stage gametocyte development and results in differential timing for sex-specific transcripts. The transcriptional dynamics suggest strict transcriptional control during gametocytogenesis in P. falciparum, which we propose is mediated by putative regulators including epigenetic mechanisms (driving active repression of proliferation-associated processes) and a cascade-like expression of ApiAP2 transcription factors. Conclusions : The gametocyte transcriptome serves as the blueprint for sexual differentiation and will be a rich resource for future functional studies on this critical stage of Plasmodium development, as the intraerythrocytic transcriptome has been for our understanding of the asexual cycle.

scholarly journals Disruption of Plasmodium falciparum histidine-rich protein II may affect haem metabolism in the blood stage

2020 ◽  
Author(s):  
Yingchao Yang ◽  
Tongke Tang ◽  
Bo Feng ◽  
Shanshan Li ◽  
Nan Hou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
De Novo ◽  
Transcript Level ◽  
Blood Stage ◽  
Gene Transcript ◽  
Parasite Line ◽  
Haem Biosynthesis ◽  
Comparison Groups ◽  
Transgenic Parasites

Abstract Background. Haem is a key metabolic factor in the life cycle of the malaria parasite. In the blood stage, the parasite acquires host haemoglobin to generate amino acids for protein synthesis and the by-product haem for metabolic use. The malaria parasite can also synthesize haem de novo by itself. Plasmodium falciparum-specific histidine-rich protein 2 (PfHRP2) has a haem-binding site to mediate the formation of haemozoin, a biocrystallized form of haem aggregates. Notably, the gene regulates the mechanism of haemoglobin-derived haem metabolism and the de novo haem biosynthetic pathway in the Pfhrp2-disrupted parasite line during the intraerythrocytic stages. Methods. The CRISPR/Cas9 system was used to disrupt the gene locus of Pfhrp2. DNA was extracted from the transgenic parasite, and polymerase chain reaction (PCR), Southern blotting and Western blotting were used to confirm the establishment of transgenic parasites. RNA-Seq and comparative transcriptome analysis were performed to identify differences in gene expression between 3D7 and Pfhrp2- 3D7 parasites.Results. Pfhrp2- transgenic parasites were successfully established by the CRISPR/Cas9 system. A total of 964, 1261, 3138, 1064, 2512, and 1778 differentially expressed genes (DEGs) were identified in the six comparison groups, and a total of 373, 520, 1499, 353, 1253, and 742 of the DEGs were upregulated, and 591, 741, 1639, 711, 1259, and 1036 of the DEGs were downregulated, respectively. Five DEGs related to haem metabolism and synthesis were identified in the comparison groups of six time points (0, 8, 16, 24, 32, and 40 h after merozoite invasion). The genes encoding ALAS and FC, related to haem biosynthesis, were found to be significantly upregulated in the comparison groups, and the HO, SPP, and PBGD genes were found to be significantly downregulated. No GO terms were significantly enriched in haem-related processes (Q value=1).Conclusion: In this study, our findings revealed changes in the transcriptome expression profile of the Pfhrp2-3D7 parasite during the intraerythrocytic stages. The results suggested that disruption of Pfhrp2 alters the parasite’s haem metabolic and biosynthesis pathways at the gene transcript level. A cooperative mechanism exists between the haem biosynthesis and metabolic pathways for parasite growth and survival in the blood stage. It is difficult to treat malaria patients by inhibiting only one pathway with traditional antimalarial drugs. The above findings provide insight at the gene transcript level for further research and development of anti-malaria drugs.

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