|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
RED CELLS
From the Howard University, Washington, DC; and Cell
Biology and Metabolism Branch, National Institute of Child Health and
Human Development, National Institutes of Health, Bethesda, MD.
This study cloned and sequenced the complementary DNA (cDNA)
encoding of a putative malarial iron responsive element-binding protein
(PfIRPa) 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. This article has been cited by other articles:
| |||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 2001 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
