cDNA clones encoding the murine int-1-related protein (m-irp) were isolated from an 8.5-day mouse embryo library. m-irp and its human counterpart, h-irp, share extensive nucleotide homology in coding (92%) and 3' untranslated (69%) regions. At the amino acid level, m-irp and h-irp share 97% of amino acids including all 24 cysteine residues, which are highly conserved among members of the int-1 ...

Several cellular mRNAs are regulated posttranscriptionally by iron-responsive elements (IREs) and the cytosolic IRE-binding proteins IRP-1 and IRP-2. Three different signals are known to elicit IRP-1 activity and thus regulate IRE-containing mRNAs: iron deficiency, nitric oxide (NO), and the reactive oxygen intermediate hydrogen peroxide (H2O2). In this report, we characterize the pathways for ...

BACKGROUND Despite successful treatment and CD4+ T-cell recovery, HIV-infected individuals often experience a profound immune dysregulation characterized by a persistently low CD4:CD8 T-cell ratio. This residual immune dysregulation is reminiscent of the Immune Risk Phenotype (IRP) previously associated with morbidity and mortality in the uninfected elderly (>85 years). The IRP consists of labo...

Placental iron transport during the last trimester of pregnancy determines the iron endowment of the neonate. Iron transport is a function of the major iron transport proteins: transferrin receptor-1 (TfR-1) and ferroportin-1 (FPN-1). The mRNAs for TfR-1 and, potentially, FPN-1 are posttranscriptionally regulated by iron regulatory protein (IRP)-1 and IRP-2. We assessed the effect of gestationa...

Placental iron transport during the last trimester of pregnancy determines the iron endowment of the neonate. Iron transport is a function of the major iron transport proteins, transferrin receptor-1 (TfR-1) and ferroportin-1 (FPN-1). The mRNAs for TfR-1, and potentially FPN-1, are post-transcriptionally regulated by iron regulatory protein-1 (IRP-1) and -2 (IRP-2). We assessed the effect of ge...

Cytokine-treated macrophages represent a useful model to unravel the molecular basis of reticuloendothelial (RE) iron retention in inflammatory conditions. In the present study, we showed that stimulation of murine macrophage J774 cells with interferon (IFN)-gamma/lipopolysaccharide (LPS) resulted in a nitric oxide-dependent modulation of the activity of iron regulatory proteins (IRP)-1 and 2, ...