Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2011 Jul 1;286(26):23266-79. doi: 10.1074/jbc.M111.229674. Epub 2011 May 10.

LFR1 ferric iron reductase of Leishmania amazonensis is essential for the generation of infective parasite forms.

Author information

  • 1Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742-5815, USA.

Abstract

The protozoan parasite Leishmania is the causative agent of serious human infections worldwide. The parasites alternate between insect and vertebrate hosts and cause disease by invading macrophages, where they replicate. Parasites lacking the ferrous iron transporter LIT1 cannot grow intracellularly, indicating that a plasma membrane-associated mechanism for iron uptake is essential for the establishment of infections. Here, we identify and functionally characterize a second member of the Leishmania iron acquisition pathway, the ferric iron reductase LFR1. The LFR1 gene is up-regulated under iron deprivation and accounts for all the detectable ferric reductase activity exposed on the surface of Leishmania amazonensis. LFR1 null mutants grow normally as promastigote insect stages but are defective in differentiation into the vertebrate infective forms, metacyclic promastigotes and amastigotes. LFR1 overexpression partially restores the abnormal morphology of infective stages but markedly reduces parasite viability, precluding its ability to rescue LFR1 null replication in macrophages. However, LFR1 overexpression is not toxic for amastigotes lacking the ferrous iron transporter LIT1 and rescues their growth defect. In addition, the intracellular growth of both LFR1 and LIT1 null parasites is rescued in macrophages loaded with exogenous iron. This indicates that the Fe(3+) reductase LFR1 functions upstream of LIT1 and suggests that LFR1 overexpression results in excessive Fe(2+) production, which impairs parasite viability after intracellular transport by LIT1.

PMID:
21558274
[PubMed - indexed for MEDLINE]
PMCID:
PMC3123093
Free PMC Article

Images from this publication.See all images (8)Free text

FIGURE 1.
FIGURE 2.
FIGURE 3.
FIGURE 4.
FIGURE 5.
FIGURE 6.
FIGURE 7.
FIGURE 8.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk