scholarly journals The Plasmodium falciparum protein PfMRP1 functions as an influx ABC transporter

2022 ◽  
Author(s):  
Miguel Silva ◽  
Carla Calçada ◽  
Nuno Osório ◽  
Vitória Baptista ◽  
Vandana Thathy ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Abc Transporter ◽  
Abc Transporters ◽  
Malaria Parasite ◽  
Drug Transport ◽  
Parasite Species ◽  
Antimalarial Activity ◽  
Falciparum Protein

Abstract Adenosine triphosphate (ATP)-binding cassette (ABC) transporters play an important role in mediating solute or drug transport across cellular membranes. Although this class of transporters has been well characterized in diverse organisms little is known about the physiological roles in Plasmodium falciparum, the deadliest malaria parasite species. We studied the Plasmodium falciparum Multidrug Resistance-associated Protein 1 (PfMRP1; PF3D7_0112200), an ABC transporter localized to the parasite plasma membrane, generating genetic disrupted parasites. We demonstrate that parasites with disrupted pfmrp1 are resistant to folate analogs, methotrexate and aminopterin, with antimalarial activity. This phenotype occurs due to reduction in compound accumulation in the parasite cytoplasm. Phylogenetic analysis supports pfmrp1 being distantly related to ABC transporters in other eukaryotes, suggesting an unusual function. We propose that PfMRP1 can act as a solute importer, a function not previously observed in this organism.

Actomyosin motor in the merozoite of the malaria parasite, Plasmodium falciparum: implications for red cell invasion

1998 ◽  
Vol 111 (13) ◽  
pp. 1831-1839 ◽  
Author(s):  
J.C. Pinder ◽  
R.E. Fowler ◽  
A.R. Dluzewski ◽  
L.H. Bannister ◽  
F.M. Lavin ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Toxoplasma Gondii ◽  
Malaria Parasite ◽  
Cellular Protein ◽  
Red Cell ◽  
Parasite Protein ◽  
Ionic Detergent ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

The genome of the malaria parasite, Plasmodium falciparum, contains a myosin gene sequence, which bears a close homology to one of the myosin genes found in another apicomplexan parasite, Toxoplasma gondii. A polyclonal antibody was generated against an expressed polypeptide of molecular mass 27,000, based on part of the deduced sequence of this myosin. The antibody reacted with the cognate antigen and with a component of the total parasite protein on immunoblots, but not with vertebrate striated or smooth muscle myosins. It did, however, recognise two components in the cellular protein of Toxoplasma gondii. The antibody was used to investigate stage-specificity of expression of the myosin (here designated Pf-myo1) in P. falciparum. The results showed that the protein is synthesised in mature schizonts and is present in merozoites, but vanishes after the parasite enters the red cell. Pf-myo1 was found to be largely, though not entirely, associated with the particulate parasite cell fraction and is thus presumably mainly membrane bound. It was not solubilised by media that would be expected to dissociate actomyosin or myosin filaments, or by non-ionic detergent. Immunofluorescence revealed that in the merozoite and mature schizont Pf-myo1 is predominantly located around the periphery of the cell. Immuno-gold electron microscopy also showed the presence of the myosin around almost the entire parasite periphery, and especially in the region surrounding the apical prominence. Labelling was concentrated under the plasma membrane but was not seen in the apical prominence itself. This suggests that Pf-myo1 is associated with the plasma membrane or with the outer membrane of the subplasmalemmal cisterna, which forms a lining to the plasma membrane, with a gap at the apical prominence. The results lead to a conjectural model of the invasion mechanism.

Cloning of a Ca(2+)-ATPase gene of Plasmodium falciparum and comparison with vertebrate Ca(2+)-ATPases

1993 ◽  
Vol 104 (4) ◽  
pp. 1129-1136 ◽  
Author(s):  
M. Kimura ◽  
Y. Yamaguchi ◽  
S. Takada ◽  
K. Tanabe
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Phosphorylation Site ◽  
Genomic Libraries ◽  
Atpase Gene ◽  
Binding Regions ◽  
Cloned Gene ◽  
Falciparum Protein

A Ca(2+)-ATPase gene was cloned from the genomic libraries of Plasmodium falciparum. From the deduced amino acid sequence of the gene, a 139 kDa protein with a total of 1228 amino acids was predicted. Sequence of a partial cDNA clone of the gene identified two introns near the 3′-end at the regions identical to the regions assumed for the Ca(2+)-ATPase gene of P. yoelii, a rodent malaria species. As compared with a variety of Ca(2+)-ATPases, the P. falciparum Ca(2+)-ATPase had the highest amino acid sequence homology (78%) to the P. yoelii Ca(2+)-ATPase, moderate homology (45-50%) to vertebrate sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases (SERCAs), and lowest homology (20%) to a plasma membrane Ca(2+)-ATPase. The P. falciparum protein conserved sequences and residues that are important for the function and/or structure of the organellar type Ca(2+)-ATPase, such as high affinity Ca(2+)-binding sites, fluorescein isothiocyanate (FITC)-binding regions, and the phosphorylation site, but the protein did not contain calmodulin-binding regions that occur in the plasma membrane type Ca(2+)-ATPase. Thus we concluded the cloned gene was the organellar type Ca(2+)-ATPase of P. falciparum. In a region between the phosphorylation site and FITC-binding region, the P. falciparum protein was about 200 residues longer than the rabbit SERCA and lacked a sequence that binds to phospholamban, a protein that regulates the activity of the rabbit SERCA.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of Seasonality and Ecological Factors on the Prevalence of the Four Malaria Parasite Species in Northern Mali

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ousmane A. Koita ◽  
Lansana Sangaré ◽  
Hammadoun A. Sango ◽  
Sounkalo Dao ◽  
Naffet Keita ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Parasite Species ◽  
Ecological Factors ◽  
Seasonal Fluctuation ◽  
Parasite Prevalence ◽  
Dry Season ◽  
Sahara Desert ◽  
Cross Sectional ◽  
Hot Dry Season

Background. We performed 2 cross-sectional studies in Ménaka in the Northeastern Mali across 9 sites in different ecological settings: 4 sites have permanent ponds, 4 without ponds, and one (City of Ménaka) has a semipermanent pond. We enrolled 1328 subjects in May 2004 (hot dry season) and 1422 in February 2005 (cold dry season) after the rainy season.Objective.To examine the seasonality of malaria parasite prevalence in this dry northern part of Mali at the edge of the Sahara desert.Results. Slide prevalence was lower in hot dry than cold dry season (4.94 versus 6.85%,P=0.025). Gametocyte rate increased to 0.91% in February. Four species were identified.Plasmodium falciparumwas most prevalent (74.13 and 63.72%).P. malariaeincreased from 9.38% to 22.54% in February. In contrast, prevalence ofP. vivaxwas higher (10.31%) without seasonal variation. Smear positivity was associated with splenomegaly (P=0.007). Malaria remained stable in the villages with ponds (P=0.221); in contrast, prevalence varied between the 2 seasons in the villages without ponds (P=0.004).Conclusion. Malaria was mesoendemic; 4 species circulates with a seasonal fluctuation forPlasmodium falciparum.

scholarly journals Inhibition of the peroxidative degradation of haem as the basis of action of chloroquine and other quinoline antimalarials

1999 ◽  
Vol 339 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Paul LORIA ◽  
Susanne MILLER ◽  
Michael FOLEY ◽  
Leann TILLEY
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Antimalarial Activity ◽  
Inhibitory Effect ◽  
Food Vacuole ◽  
Equimolar Concentration

The malaria parasite feeds by degrading haemoglobin in an acidic food vacuole, producing free haem moieties as a by-product. The haem in oxyhaemoglobin is oxidized from the Fe(II) state to the Fe(III) state with the consequent production of an equimolar concentration of H2O2. We have analysed the fate of haem molecules in Plasmodium falciparum-infected erythrocytes and have found that only about one third of the haem is polymerized to form haemozoin. The remainder appears to be degraded by a non-enzymic process which leads to an accumulation of iron in the parasite. A possible route for degradation of the haem is by reacting with H2O2, and we show that, under conditions designed to resemble those found in the food vacuole, i.e., at pH 5.2 in the presence of protein, free haem undergoes rapid peroxidative decomposition. Chloroquine and quinacrine are shown to be efficient inhibitors of the peroxidative destruction of haem, while epiquinine, a quinoline compound with very low antimalarial activity, has little inhibitory effect. We also show that chloroquine enhances the association of haem with membranes, while epiquinine inhibits this association, and that treatment of parasitized erythrocytes with chloroquine leads to a build-up of membrane-associated haem in the parasite. We suggest that chloroquine exerts its antimalarial activity by causing a build-up of toxic membrane-associated haem molecules that eventually destroy the integrity of the malaria parasite. We have further shown that resistance-modulating compounds, such as chlorpromazine, interact with haem and efficiently inhibit its degradation. This may explain the weak antimalarial activities of these compounds.

Evidence for a role for a Plasmodium falciparum homologue of Sec31p in the export of proteins to the surface of malaria parasite-infected erythrocytes

2001 ◽  
Vol 114 (18) ◽  
pp. 3377-3386
Author(s):  
Akinola Adisa ◽  
Frank R. Albano ◽  
John Reeder ◽  
Michael Foley ◽  
Leann Tilley
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Malaria Parasite ◽  
Relative Molecular Mass ◽  
Western Blots ◽  
Confocal Immunofluorescence Microscopy ◽  
Confocal Immunofluorescence ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Nonionic Detergent

The malaria parasite, Plasmodium falciparum, spends part of its life cycle inside the enucleated erythrocytes of its human host. The parasite modifies the cytoplasm and plasma membrane of its host cell by exporting proteins beyond the confines of its own plasma membrane. We have previously provided evidence that a plasmodial homologue of the COPII protein, Sar1p, is involved in the trafficking of proteins across the erythrocyte cytoplasm. We have now characterised an additional plasmodial COPII protein homologue, namely Sec31p. Recombinant proteins corresponding to the WD-40 and the intervening domains of the PfSec31p sequence were used to raise antibodies. The affinity-purified antisera recognised a protein with an apparent relative molecular mass of 1.6×105 on western blots of malaria parasite-infected erythrocytes but not on blots of uninfected erythrocytes. PfSec31p was shown to be largely insoluble in nonionic detergent, suggesting cytoskeletal attachment. Confocal immunofluorescence microscopy of malaria parasite-infected erythrocytes was used to show that PfSec31p is partly located within the parasite and partly exported to structures outside the parasite in the erythrocyte cytoplasm. We have also shown that PfSec31p and PfSar1p occupy overlapping locations. Furthermore, the location of PfSec31p overlaps that of the cytoadherence-mediating protein PfEMP1. These data support the suggestion that the malaria parasite establishes a vesicle-mediated trafficking pathway outside the boundaries of its own plasma membrane – a novel paradigm in eukaryotic biology.

scholarly journals Plants of the Araceae family for malaria and related diseases: a review

2015 ◽  
Vol 17 (4) ◽  
pp. 657-666 ◽  
Author(s):  
G. FRAUSIN ◽  
R. B. S. LIMA ◽  
A. F. HIDALGO ◽  
L. C. MING ◽  
A.M. POHLIT
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Preparation Method ◽  
Antimalarial Activity ◽  
Composition Studies ◽  
In Vitro Growth ◽  
Human Malaria Parasite ◽  
Google Books ◽  
In Vitro Inhibition

ABSTRACTIn the current work we performed a review of the Araceae family species traditionally used to treat malaria and its symptoms. The aim is to reveal the large number of antimalarial Araceae species used worldwide and their great unexplored potential as sources of antimalarial natural products. The SciFinder Scholar, Scielo, PubMed, ScienceDirect and Google books search engines were consulted. Forty-three records of 36 species and 23 genera of Araceae used for malaria and symptoms treatment were found. The neotropical genera Philodendron Schott and Anthurium Schott were the best represented for the use in the treatment of malaria, fevers, liver problems and headaches. Leaves and tubers were the most used parts and decoction was the most common preparation method. The extracts of Araceae species inhibit the in vitro growth of the human malaria parasite, the Plasmodium falciparum Welch, and significant median inhibitory concentrations (IC50) for extracts of guaimbê-sulcado (Rhaphidophora decursiva (Roxb.) Schott), aninga (Montrichardia linifera (Arruda) Schott), Culcasia lancifolia N.E. Br. and forest anchomanes (Anchomanes difformis (Blume) Engl.) have been reported demonstrating the antimalarial and cytotoxicity potential of the extracts and sub-fractions. In the only report about the antimalarial components of this family, the neolignan polysyphorin and the benzoperoxide rhaphidecurperoxin presented strong in vitro inhibition of the D6 and W2 strains of Plasmodiumfalciparum (IC50 = 368-540 ng/mL). No live study about antimalarial activity in animal models has been conducted on a species of Araceae. More bioguided chemical composition studies about the in vitro and also thein vivo antimalarial activity of the Araceae are needed in order to enhance the knowledge about the antimalarial potential of this family.

scholarly journals In Vitro Activity of Riboflavin against the Human Malaria Parasite Plasmodium falciparum

2000 ◽  
Vol 44 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Thomas Akompong ◽  
Nafisa Ghori ◽  
Kasturi Haldar
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Antimalarial Activity ◽  
Food Vacuole ◽  
Host Cells ◽  
Asexual Parasite ◽  
Human Malaria Parasite ◽  
Human Malaria ◽  
Average Size

ABSTRACT The human malaria parasite Plasmodium falciparumdigests hemoglobin and polymerizes the released free heme into hemozoin. This activity occurs in an acidic organelle called the food vacuole and is essential for survival of the parasite in erythrocytes. Since acidic conditions are known to enhance the auto-oxidation of hemoglobin, we investigated whether hemoglobin ingested by the parasite was oxidized and whether the oxidation process could be a target for chemotherapy against malaria. We released parasites from their host cells and separately analyzed hemoglobin ingested by the parasites from that remaining in the erythrocytes. Isolated parasites contained elevated amounts (38.5% ± 3.5%) of oxidized hemoglobin (methemoglobin) compared to levels (0.8% ± 0.2%) found in normal, uninfected erythrocytes. Further, treatment of infected cells with the reducing agent riboflavin for 24 h decreased the parasite methemoglobin level by 55%. It also inhibited hemozoin production by 50% and decreased the average size of the food vacuole by 47%. Administration of riboflavin for 48 h resulted in a 65% decrease in food vacuole size and inhibited asexual parasite growth in cultures. High doses of riboflavin are used clinically to treat congenital methemoglobinemia without any adverse side effects. This activity, in conjunction with its impressive antimalarial activity, makes riboflavin attractive as a safe and inexpensive drug for treating malaria caused by P. falciparum.

scholarly journals Phycocyanin Extraction from Spirulina platensis and Its Antimalarial Activity In-Vitro

2016 ◽  
Vol 19 (1) ◽  
pp. 17 ◽  
Author(s):  
Diah Anggraini Wulandari ◽  
Iriani Setyaningsih ◽  
Din Syafrudin ◽  
Puji Budi Setia Asih
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Solvent Extraction ◽  
Ammonium Sulphate ◽  
Phosphate Buffer ◽  
Spirulina Platensis ◽  
Water Surface ◽  
Antimalarial Activity ◽  
Pigment Protein Complex

<p>Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family which is<br />often found in cyanobacteria. The product phycocyanin produced by phanizomenon flos-aquae and Spirulina<br />sp. The aim of this study were to determine the best solvents purification phycocanin from Spirulina platensis<br />in three solvents, phosphate buffer, water and aceton ammonium sulphate and to evaluate the antimalarial<br />activity in vitro of phycocyanin in the best solvent extraction from S. platensis. The method of this study was<br />using in-vitro antimalarial method. The result showed C- phycocyanin (C-PC), yield, and protein contents<br />of phycocyanin were 8 mg/mL, 20.22%, 1.88% extracted and purified by phosphate buffer, 6.63 mg/mL,<br />16.58 %, 3.51% extracted and purified by water, 2.86 mg/mL, 7.15%, 8.4% extracted and purified by acetone<br />ammonium sulphate respectively. Phosphate buffer was the best solvent of phycocyanin extraction from S.<br />platensis. Antimalarial activity in vitro of phycocyanin in hosphate buffer against Plasmodium falciparum<br />strains 3D7 with IC50 was 158,489 μg/mL. The possible mechanism might be relied on the destruction of<br />polymerization of Haemozoin by binding of C-PC with ferriprotoporphyrin-IX at the water surface of the<br />plasma membrane.</p>

scholarly journals Inhibition of Plasmodium falciparum Choline Kinase by Hexadecyltrimethylammonium Bromide: a Possible Antimalarial Mechanism

2006 ◽  
Vol 51 (2) ◽  
pp. 696-706 ◽  
Author(s):  
Vinay Choubey ◽  
Pallab Maity ◽  
Mithu Guha ◽  
Sanjay Kumar ◽  
Kumkum Srivastava ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Antimalarial Activity ◽  
Plasmodium Yoelii ◽  
Head Group ◽  
Hexadecyltrimethylammonium Bromide ◽  
Choline Kinase ◽  
Polar Head Group ◽  
Dependent Manner

ABSTRACT Choline kinase is the first enzyme in the Kennedy pathway (CDP-choline pathway) for the biosynthesis of the most essential phospholipid, phosphatidylcholine, in Plasmodium falciparum. In addition, choline kinase also plays a pivotal role in trapping essential polar head group choline inside the malaria parasite. Recently, Plasmodium falciparum choline kinase (PfCK) has been cloned, overexpressed, and purified. However, the function of this enzyme in parasite growth and survival has not been evaluated owing to the lack of a suitable inhibitor. Purified recombinant PfCK enabled us to identify an inhibitor of PfCK, hexadecyltrimethylammonium bromide (HDTAB), which has a very close structural resemblance to hexadecylphosphocholine (miltefosin), the well-known antiproliferative and antileishmanial drug. HDTAB inhibited PfCK in a dose-dependent manner and offered very potent antimalarial activity in vitro against Plasmodium falciparum. Moreover, HDTAB exhibited profound antimalarial activity in vivo against the rodent malaria parasite Plasmodium yoelii (N-67 strain). Interestingly, parasites at the trophozoite and schizont stages were found to be particularly sensitive to HDTAB. The stage-specific antimalarial effect of HDTAB correlated well with the expression pattern of PfCK in P. falciparum, which was observed by reverse transcription-PCR and immunofluorescence microscopy. Furthermore, the antimalarial activity of HDTAB paralleled the decrease in phosphatidylcholine content, which was found to correlate with the decreased phosphocholine generation. These results suggest that inhibition of choline kinase by HDTAB leads to decreased phosphocholine, which in turn causes a decrease in phosphatidylcholine biosynthesis, resulting in death of the parasite.

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