An IRP-like protein from Plasmodium falciparum binds to a mammalian iron-responsive element
This study cloned and sequenced the complementary DNA (cDNA) encoding of a putative malarial iron responsive element-binding protein (PflRPa) and confirmed its identity to the previously identified iron-regulatory protein (IRP)-like cDNA from Plasmodium falciparum. Sequence alignment showed that the plasmodial sequence has 47% identity with human IRP1. Hemoglobin-free lysates obtained from erythrocyte-stage P falciparum contain a protein that binds a consensus mammalian iron-responsive element (IRE), indicating that a protein(s) with iron-regulatory activity was present in the lysates. IRE-binding activity was found to be iron regulated in the electrophoretic mobility shift assays. Western blot analysis showed a 2-fold increase in the level of PfIRPa in the desferrioxamine-treated cultures versus control or iron-supplemented cells. Malarial IRP was detected by anti-PfIRPa antibody in the IRE-protein complex from P falciparum lysates. Immunofluorescence studies confirmed the presence of PfIRPa in the infected red blood cells. These findings demonstrate that erythrocyte P falciparum contains an iron-regulated IRP that binds a mammalian consensus IRE sequence, raising the possibility that the malaria parasite expresses transcripts that contain IREs and are iron-dependently regulated. © 2001 by The American Society of Hematology.
Loyevsky, Mark; LaVaute, Timothy; Allerson, Charles R.; Stearman, Robert; Kassim, Olakunle O.; Cooperman, Sharon; Gordeuk, Victor R.; and Rouault, Tracey A., "An IRP-like protein from Plasmodium falciparum binds to a mammalian iron-responsive element" (2001). The Center For Sickle Cell Disease Faculty Publications. 240.