scholarly journals Characterization of the choline carrier of Plasmodium falciparum: a route for the selective delivery of novel antimalarial drugs

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3372-3377 ◽  
Author(s):  
Giancarlo A. Biagini ◽  
Erica M. Pasini ◽  
Ruth Hughes ◽  
Harry P. De Koning ◽  
Henri J. Vial ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Infected Erythrocyte ◽  
Antimalarial Drugs ◽  
New Drugs ◽  
Erythrocyte Membranes ◽  
Great Promise ◽  
Intracellular Parasite ◽  
Choline Transporter

Abstract New drugs are urgently needed to combat the growing problem of drug resistance in Plasmodium falciparum malaria. The infected erythrocyte is a multicompartmental system, and its transporters are of interest as drug targets in their own right and as potential routes for the delivery of antimalarial drugs. Choline is an important nutrient that penetrates infected erythrocyte membranes through the endogenous carrier and through parasite-induced permeability pathways, but nothing is known about its transport into the intracellular parasite. Here we present the first characterization of choline transport across the parasite membrane. Transport exhibits Michaelis-Menten kinetics with an apparent Km of 25.0 ± 3.5 μM for choline. The carrier is inhibitor-sensitive, temperature-dependent, and Na+-independent, and it is driven by the proton-motive force. Highly active bis-amidine and bis-quaternary ammonium compounds are also known to penetrate the host erythrocyte membrane through parasite-induced permeability pathways. Here, we demonstrate that the parasite choline transporter mediates the delivery of these compounds to the intracellular parasite. Thus, the induced permeability pathways in the host erythrocyte membrane and the parasite choline transporter described here form a cooperative transport system that shows great promise for the selective targeting of new agents for the chemotherapy of malaria. (Blood. 2004;104: 3372-3377)

Characterization of membrane proteins exported from Plasmodium falciparum into the host erythrocyte

Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 1-9 ◽  
Author(s):  
D. Johnson ◽  
K. Günther ◽  
I. Ansorge ◽  
J. Benting ◽  
A. Kent ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Membrane Proteins ◽  
Infected Erythrocyte ◽  
Parasitophorous Vacuole ◽  
Specific Marker ◽  
Intracellular Parasite ◽  
Membrane Bound ◽  
Exported Protein ◽  
35 Kda Protein

SUMMARYPlasmodium falciparum is an intracellular parasite of the red blood cell. During development it exports proteins which are transported to specific locations within the host erythrocyte. We have begun to identify and characterize exported membrane proteins of P.falciparum in order to obtain specific marker molecules for the study of the mechanisms involved in the distribution of parasite-derived proteins within the host cell. In this report we describe the characterization of a 35 kDa protein which is recognized by a monoclonal antibody. The protein is tightly associated with membranes isolated from infected erythrocytes; it is resistant to extraction with alkali and soluble after treatment with detergents. It is located at the membrane of the parasitophorous vacuole and in membrane-bound compartments which appear in the cytoplasm of the infected erythrocyte. The protein co-localizes with the previously described exported protein-1 (exp-1). Considering its localization and physical similarities to exp-1, we name the 35 kDa protein the exported protein-2 (exp-2).

scholarly journals Transport of fluorescent phospholipid analogues from the erythrocyte membrane to the parasite in Plasmodium falciparum-infected cells.

1989 ◽  
Vol 108 (6) ◽  
pp. 2183-2192 ◽  
Author(s):  
K Haldar ◽  
A F de Amorim ◽  
G A Cross
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Infected Erythrocyte ◽  
Lucifer Yellow ◽  
Lipid Transport ◽  
Membrane Properties ◽  
Erythrocyte Membranes ◽  
Flip Flop ◽  
Host Membrane ◽  
Infected Cells

The asexual development of the human malaria parasite Plasmodium falciparum is largely intraerythrocytic. When 1-palmitoyl-2-[6-[(7-nitro-2-1,3-benzoxadiazole-4-yl)amino]caproyl] phosphatidylcholine (NBD-PC) was incorporated into infected and uninfected erythrocyte membranes at 0 degrees C, it remained at the cell surface. At 10 degrees C, the lipid was rapidly internalized in infected erythrocytes at all stages of parasite growth. Our results indicate that the internalization of NDB-PC was not because of endocytosis but rapid transbilayer lipid flip-flop at the infected erythrocyte membrane, followed by monomer diffusion to the parasite. Internalization of the lipid was inhibited by (a) depleting cellular ATP levels; (b) pretreating the cells with N-ethyl maleimide or diethylpyrocarbonate; and (c) 10 mM L-alpha-glycerophosphorylcholine. The evidence suggests protein-mediated and energy dependent transmembrane movement of the PC analogue. The conditions for the internalization of another phospholipid analogue N-4-nitrobenzo-2-oxa-1,3-diazoledipalmitoyl phosphatidylethanolamine (N-NBD-PE) were distinct from that of NBD-PC and suggest the presence of additional mechanism(s) of parasite-mediated lipid transport in the infected host membrane. In spite of the lack of bulk, constitutive endocytosis at the red cell membrane, the uptake of Lucifer yellow by mature infected cells suggests that microdomains of pinocytotic activity are induced by the intracellular parasite. The results indicate the presence of parasite-induced mechanisms of lipid transport in infected erythrocyte membranes that modify host membrane properties and may have important implications on phospholipid asymmetry in these membranes.

scholarly journals Trafficking and Association of Plasmodium falciparum MC-2TM with the Maurer’s Clefts

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Raghavendra Yadavalli ◽  
John W. Peterson ◽  
Judith A. Drazba ◽  
Tobili Y. Sam-Yellowe
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Sodium Carbonate ◽  
Infected Erythrocyte ◽  
Brefeldin A ◽  
Specific Expression ◽  
Lipid Interactions ◽  
And Topology ◽  
Streptolysin O ◽  
Maurer's Clefts

In this study, we investigated stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in P. falciparum (3D7) infected erythrocytes. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence with antibodies reactive with PfMC-2TM. PfMC-2TM is sensitive to BFA treatment and permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associated with the MC and infected erythrocyte membrane and was resistant to extraction with alkaline sodium carbonate, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM is an additional marker of the nascent MCs.

scholarly journals Membrane glycopeptides from old and young human erythrocytes (Short Communication)

1974 ◽  
Vol 140 (3) ◽  
pp. 557-560 ◽  
Author(s):  
Cesare Balduini ◽  
Carlo Luigi Balduini ◽  
Edoardo Ascari
Keyword(s):  
Sialic Acid ◽  
Erythrocyte Membrane ◽  
Human Erythrocyte ◽  
Short Communication ◽  
Chemical Characterization ◽  
Erythrocyte Membranes ◽  
Main Peak ◽  
Human Erythrocyte Membranes ◽  
Papain Digestion

Glycopeptides were extracted by papain digestion from old and young human erythrocyte membranes and fractionated on DEAE-Sephadex A-25. Chemical characterization of the unfractionated samples and of the main peak eluted from the column indicates that glycoproteins of the erythrocyte membrane undergo significant decreases in sialic acid and galactosamine content with aging.

scholarly journals Plasmodium falciparum Resistance to a Lead Benzoxaborole Due to Blocked Compound Activation and Altered Ubiquitination or Sumoylation

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Kirthana M. V. Sindhe ◽  
Wesley Wu ◽  
Jenny Legac ◽  
Yong-Kang Zhang ◽  
Eric E. Easom ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Stress Responses ◽  
Mechanisms Of Action ◽  
Antimalarial Drugs ◽  
New Drugs ◽  
Loss Of Function ◽  
Content Type ◽  
High Level ◽  
Level Resistance

ABSTRACT New antimalarial drugs are needed. The benzoxaborole AN13762 showed excellent activity against cultured Plasmodium falciparum, against fresh Ugandan P. falciparum isolates, and in murine malaria models. To gain mechanistic insights, we selected in vitro for P. falciparum isolates resistant to AN13762. In all of 11 independent selections with 100 to 200 nM AN13762, the 50% inhibitory concentration (IC50) increased from 18–118 nM to 180–890 nM, and whole-genome sequencing of resistant parasites demonstrated mutations in prodrug activation and resistance esterase (PfPARE). The introduction of PfPARE mutations led to a similar level of resistance, and recombinant PfPARE hydrolyzed AN13762 to the benzoxaborole AN10248, which has activity similar to that of AN13762 but for which selection of resistance was not readily achieved. Parasites further selected with micromolar concentrations of AN13762 developed higher-level resistance (IC50, 1.9 to 5.0 μM), and sequencing revealed additional mutations in any of 5 genes, 4 of which were associated with ubiquitination/sumoylation enzyme cascades; the introduction of one of these mutations, in SUMO-activating enzyme subunit 2, led to a similar level of resistance. The other gene mutated in highly resistant parasites encodes the P. falciparum cleavage and specificity factor homolog PfCPSF3, previously identified as the antimalarial target of another benzoxaborole. Parasites selected for resistance to AN13762 were cross-resistant with a close analog, AN13956, but not with standard antimalarials, AN10248, or other benzoxaboroles known to have different P. falciparum targets. Thus, AN13762 appears to have a novel mechanism of antimalarial action and multiple mechanisms of resistance, including loss of function of PfPARE preventing activation to AN10248, followed by alterations in ubiquitination/sumoylation pathways or PfCPSF3. IMPORTANCE Benzoxaboroles are under study as potential new drugs to treat malaria. One benzoxaborole, AN13762, has potent activity and promising features, but its mechanisms of action and resistance are unknown. To gain insights into these mechanisms, we cultured malaria parasites with nonlethal concentrations of AN13762 and generated parasites with varied levels of resistance. Parasites with low-level resistance had mutations in PfPARE, which processes AN13762 into an active metabolite; PfPARE mutations prevented this processing. Parasites with high-level resistance had mutations in any of a number of enzymes, mostly those involved in stress responses. Parasites selected for AN13762 resistance were not resistant to other antimalarials, suggesting novel mechanisms of action and resistance for AN13762, a valuable feature for a new class of antimalarial drugs.

scholarly journals Modulation of PF10_0355 (MSPDBL2) Alters Plasmodium falciparum Response to Antimalarial Drugs

2013 ◽  
Vol 57 (7) ◽  
pp. 2937-2941 ◽  
Author(s):  
Daria Van Tyne ◽  
Alessandro D. Uboldi ◽  
Julie Healer ◽  
Alan F. Cowman ◽  
Dyann F. Wirth
Keyword(s):  
Plasmodium Falciparum ◽  
Copy Number ◽  
Specific Effect ◽  
Antimalarial Drugs ◽  
New Drugs ◽  
Resistance Locus ◽  
Specific Class ◽  
Drug Pressure ◽  
Content Type ◽  
Antimalarial Resistance

ABSTRACTMalaria's ability to rapidly adapt to new drugs has allowed it to remain one of the most devastating infectious diseases of humans. Understanding and tracking the genetic basis of these adaptations are critical to the success of treatment and intervention strategies. The novel antimalarial resistance locusPF10_0355(Pfmspdbl2) was previously associated with the parasite response to halofantrine, and functional validation confirmed that overexpression of this gene lowered parasite sensitivity to both halofantrine and the structurally related antimalarials mefloquine and lumefantrine, predominantly through copy number variation. Here we further characterize the role ofPfmspdbl2in mediating the antimalarial drug response ofPlasmodium falciparum. Knockout ofPfmspdbl2increased parasite sensitivity to halofantrine, mefloquine, and lumefantrine but not to unrelated antimalarials, further suggesting that this gene mediates the parasite response to a specific class of antimalarial drugs. A single nucleotide polymorphism encoding a C591S mutation withinPfmspdbl2had the strongest association with halofantrine sensitivity and showed a high derived allele frequency among Senegalese parasites. Transgenic parasites expressing the ancestralPfmspdbl2allele were more sensitive to halofantrine and structurally related antimalarials than were parasites expressing the derived allele, revealing an allele-specific effect on drug sensitivity in the absence of copy number effects. Finally, growth competition experiments showed that under drug pressure, parasites expressing the derived allele ofPfmspdbl2outcompeted parasites expressing the ancestral allele within a few generations. Together, these experiments demonstrate that modulation ofPfmspdbl2affects malaria parasite responses to antimalarial drugs.

scholarly journals Role of the Plasmodium falciparum mature-parasite-infected erythrocyte surface antigen (MESA/PfEMP-2) in malarial infection of erythrocytes

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 3196-3204 ◽  
Author(s):  
C Magowan ◽  
RL Coppel ◽  
AO Lau ◽  
MM Moronne ◽  
G Tchernia ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Erythrocyte Membrane ◽  
Surface Antigen ◽  
Infected Erythrocyte ◽  
Spontaneous Mutant ◽  
Protein 4.1 ◽  
Erythrocyte Surface ◽  
Skeletal Protein ◽  
Parasite Viability

Abstract During intraerythrocytic growth of Plasmodium falciparum, several parasite proteins are transported from the parasite to the erythrocyte membrane, where they bind to membrane skeletal proteins. Mature-parasite-infected erythrocyte surface antigen (MESA) has previously been shown to associate with host erythrocyte membrane skeletal protein 4.1. Using a spontaneous mutant of P falciparum that has lost the ability to synthesize MESA and 4.1-deficient erythrocytes, we examined growth of MESA(+) and MESA(-) parasites in normal and 4.1-deficient erythrocytes. Viability of MESA(+) parasites was reduced in 4.1-deficient erythrocytes as compared with that for normal erythrocytes, but MESA(-) parasites grew equally well in 4.1-deficient and normal erythrocytes. Cytoadherence of MESA(+)- and MESA (-)-parasitized normal and 4.1-deficient erythrocytes to C32 melanoma cells was similar, indicating that neither protein 4.1 nor MESA plays a major role in cytoadherence of infected erythrocytes. Localization of MESA in normal and 4.1-deficient erythrocytes was examined by confocal microscopy. MESA was diffusely distributed in the cytosol of 4.1-deficient erythrocytes but was membrane-associated in normal erythrocytes. These findings suggest that MESA binding to protein 4.1 plays a major role in intraerythrocytic parasite viability.

scholarly journals High Prevalence of Human Antibodies to Recombinant Duffy Binding-Like α Domains of the Plasmodium falciparum-Infected Erythrocyte Membrane Protein 1 in Semi-Immune Adults Compared to That in Nonimmune Children

2001 ◽  
Vol 69 (12) ◽  
pp. 7603-7609 ◽  
Author(s):  
Raphael M. Oguariri ◽  
Steffen Borrmann ◽  
Mo-Quen Klinkert ◽  
Peter G. Kremsner ◽  
Jürgen F. J. Kun
Keyword(s):  
Plasmodium Falciparum ◽  
Membrane Protein ◽  
Erythrocyte Membrane ◽  
Fusion Proteins ◽  
Infected Erythrocyte ◽  
Antibody Responses ◽  
Antibody Activity ◽  
Serum Samples ◽  
Erythrocyte Membrane Protein ◽  
High Level

ABSTRACT We used a panel of nine fusion proteins that contain different Duffy binding-like α (DBL-α) domains ofPlasmodium falciparum-infected erythrocyte membrane protein 1 to assess the levels of antibody activity in serum samples obtained from semi-immune or nonimmune individuals from Lambaréné, Gabon. Recognition was measured in terms of either the prevalence or the magnitude of the response. A strong correlation between the immune status of the patients and reactivity with recombinant proteins was observed, which was interpreted as a reflection of the number of infections acquired over time. The antibody responses were predominantly directed toward variable epitopes of the DBL-α domain. Antibody responses could be reduced by preincubation of the sera with various fusion proteins. A portion of individuals who exhibited high-level responses to all fusion proteins also had antibodies which recognized conserved epitopes. The possibility that a synergizing effect of anti-DBL-α domain antibodies could support chemotherapy is discussed.

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