Identification and functional analysis of proteins involved in the invasion of human erythrocytes by the malaria parasite Plasmodium falciparum

2000 ◽  
Vol 28 (5) ◽  
pp. A116-A116
Author(s):  
A. F. Cowman ◽  
M. B. Reed ◽  
T. Triglia ◽  
J. K. Thompson ◽  
D. L. Baldi ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Human Erythrocytes ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

Water and urea transport in human erythrocytes infected with the malaria parasite Plasmodium falciparum

1990 ◽  
Vol 40 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Mary Ann Zanner ◽  
William R. Galey ◽  
Joseph V. Scaletti ◽  
Jesper Brahm ◽  
David L. Vander Jagt
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Human Erythrocytes ◽  
Urea Transport ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum

Transport of the essential nutrient isoleucine in human erythrocytes infected with the malaria parasite Plasmodium falciparum

Blood ◽  
2006 ◽  
Vol 109 (5) ◽  
pp. 2217-2224 ◽  
Author(s):  
Rowena E. Martin ◽  
Kiaran Kirk
Keyword(s):  
Plasmodium Falciparum ◽  
Host Cell ◽  
Malaria Parasite ◽  
Human Erythrocytes ◽  
Extracellular Medium ◽  
Host Cell Membrane ◽  
Trophozoite Stage ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Essential Nutrient

AbstractThe intraerythrocytic malaria parasite derives much of its requirement for amino acids from the digestion of the hemoglobin of its host cell. However, one amino acid, isoleucine, is absent from adult human hemoglobin and must therefore be obtained from the extracellular medium. In this study we have characterized the mechanisms involved in the uptake of isoleucine by the intraerythrocytic parasite. Under physiologic conditions the rate of transport of isoleucine into human erythrocytes infected with mature trophozoite-stage Plasmodium falciparum parasites is increased to approximately 5-fold that in uninfected cells, with the increased flux being via the new permeability pathways (NPPs) induced by the parasite in the host cell membrane. Transport via the NPPs ensures that protein synthesis is not rate limited by the flux of isoleucine across the erythrocyte membrane. On entering the infected erythrocyte, isoleucine is taken up into the parasite via a saturable, ATP-, Na+-, and H+-independent system which has the capacity to mediate the influx of isoleucine in exchange for leucine (liberated from hemoglobin). The accumulation of radiolabeled isoleucine within the parasite is mediated by a second (high-affinity, ATP-dependent) mechanism, perhaps involving metabolism and/or the concentration of isoleucine within an intracellular organelle.

scholarly journals Enhanced choline and Rb+ transport in human erythrocytes infected with the malaria parasite Plasmodium falciparum

1991 ◽  
Vol 278 (2) ◽  
pp. 521-525 ◽  
Author(s):  
K Kirk ◽  
H Y Wong ◽  
B C Elford ◽  
C I Newbold ◽  
J C Ellory
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Parasite ◽  
Human Erythrocytes ◽  
Transport Pathway ◽  
Choline Transport ◽  
Transport Component ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Infected Cells

Human erythrocytes infected in vitro with the malaria parasite Plasmodium falciparum showed a markedly increased rate of choline influx compared with normal cells. Choline transport into uninfected cells (cultured in parallel with infected cells) obeyed Michaelis-Menten kinetics (Km approximately 11 microM). In malaria-parasite-infected cells there was an additional choline-transport component which failed to saturate at extracellular concentrations of up to 500 microM. This component was less sensitive than the endogenous transporter to inhibition by the Cinchona bark alkaloids quinine, quinidine, cinchonine and cinchonidine, but showed a much greater sensitivity than the native system to inhibition by piperine. The sensitivity of the induced choline transport to these reagents was similar to that of the malaria-induced (ouabain- and bumetanide-resistant) Rb(+)-transport pathway; however, the relative magnitudes of the piperine-sensitive choline and Rb+ fluxes in malaria-parasite-infected cells varied between cultures. This suggests either that the enhanced transport of the two cations was via functionally distinct (albeit pharmacologically similar) pathways, or that the transport was mediated by a pathway with variable substrate selectivity.

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