Cellular Ferritin Uptake: A Highly Regulated Pathway for Iron Assimilation in Human Erythroid Precursor Cells

摘要: Normal erythropoiesis requires the regulated delivery of iron to differentiating erythroid precursor cells. The cells, in vivo, is ascribed, traditionally, exclusively transport protein transferrin (Tf)1. Ferritin regarded mainly as an detoxifying and storage protein2, its synthesis down-regulated depleted cells up-regulated when cellular abundance. a multimeric, globular composed 24 subunits surrounding central core up 4500 atoms shell can be two different heavy, (H type) light, (L type). Isoferritins rich H-type have lower Pi (Acidic isoferritins) than isoferritins L type subunits5-6. Other functions, accepted role has been assigned ferritin. accredited however, cytosolic intermediate human reticulocytes7 such possible donor for heme both, human7 mouse reticulocytes8. Isolated rat mitochondria could use ferritin ferrochelatase reaction. In addition Speyer Fielding argue that obligatory between reticulocyte plasma membrane site incorporation into heme. Biochemical electron micrograph studies on guinea-pig reticulocytes implicate presence specific receptors cell pp10-11 . binding subsequent internalization demonstrated by Blight Morgan 12. They used liver therefore mostly basic nature. These were done with circulating represent penultimate stage maturation. At this already diminished utilized13. view active metabolic erythrocyte precursors gives significance old observations Gabusda Pearson who showed erythroblast metabolically structurally distinct from reticuloendothelial proposed en route synthesis.