title: Chemical activation of a high-affinity glutamate transporter in human erythrocytes and its implications for malaria-parasite-induced glutamate uptake.
abstract: Human erythrocytes have a low basal permeability to L-glutamate and are not known to have a functional glutamate transporter. Here, treatment of human erythrocytes with arsenite was shown to induce the uptake of L-glutamate and D-aspartate, but not that of D-glutamate or L-alanine. The majority of the arsenite-induced L-glutamate influx was via a high-affinity, Na(+)-dependent system showing characteristics of members of the "excitatory amino acid transporter" (EAAT) family. Western blots and immunofluorescence assays revealed the presence of a member of this family, EAAT3, on the erythrocyte membrane. Erythrocytes infected with the malaria parasite Plasmodium falciparum take up glutamate from the extracellular environment. Although the majority of uptake is via a low-affinity Na(+)-independent pathway there is, in addition, a high-affinity uptake component, raising the possibility that the parasite activates the host cell glutamate transporter.
authors.affiliation: Faculty of Biology, Department of Parasitology, Philipps-Universität Marburg, Marburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Winterberg
authors.forename: Esther
authors.initials: E
authors.lastname: Rajendran
authors.forename: Stefan
authors.initials: S
authors.lastname: Baumeister
authors.forename: Sven
authors.initials: S
authors.lastname: Bietz
authors.forename: Kiaran
authors.initials: K
authors.lastname: Kirk
authors.forename: Klaus
authors.initials: K
authors.lastname: Lingelbach
mesh_terms: D000777:Anesthetics / Q000494:pharmacology; D018053:Arsenites / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism* / Q000469:parasitology; D050580:Excitatory Amino Acid Transporter 3 / Q000819:agonists* / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D006790:Host-Parasite Interactions / Q000502:physiology; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood / Q000378:metabolism* / Q000469:parasitology; D010963:Plasmodium falciparum / Q000502:physiology*; D011277:Pregnanediones / Q000494:pharmacology; D013268:Stimulation, Chemical; D013723:Teratogens / Q000494:pharmacology
chemical_list: D000777:Anesthetics; D018053:Arsenites; D050580:Excitatory Amino Acid Transporter 3; D011277:Pregnanediones; C493400:SLC1A1 protein, human; D013723:Teratogens; D018698:Glutamic Acid; C006477:alphaxalone; C015001:arsenite