Molecular Cell
Volume 10, Issue 5, November 2002, Pages 1045-1056
Journal home page for Molecular Cell

Article
An Iron Delivery Pathway Mediated by a Lipocalin

https://doi.org/10.1016/S1097-2765(02)00710-4Get rights and content
Under an Elsevier user license
open archive

Abstract

Despite the critical need for iron in many cellular reactions, deletion of the transferrin pathway does not block organogenesis, suggesting the presence of alternative methods to deliver iron. We show that a member of the lipocalin superfamily (24p3/Ngal) delivers iron to the cytoplasm where it activates or represses iron-responsive genes. Iron unloading depends on the cycling of 24p3/Ngal through acidic endosomes, but its pH sensitivity and its subcellular targeting differed from transferrin. Indeed, during the conversion of mesenchyme into epithelia (where we discovered the protein), 24p3/Ngal and transferrin were endocytosed by different cells that characterize different stages of development, and they triggered unique responses. These studies identify an iron delivery pathway active in development and cell physiology.

Cited by (0)

5

These authors contributed equally to the work.