Iron uptake by melanoma cells from the soluble form of the transferrin homologue, melanotransferrin.
Melanotransferrin (MTf) is a membrane-bound transferrin (Tf) homologue that can also exist in a soluble form (sMTf). Considering the high homology of MTf to Tf, it is possible to suggest that sMTf could bind to the high affinity transferrin receptor 1 (TfR1) or lower affinity TfR2. We have used sMTf labelled with 59Fe to examine its ability to donate Fe to cells. Our experiments demonstrate that sMTf is far less effective than Tf at donating Fe to cells and this does not occur via specific receptors. Indeed, the uptake of sMTf by cells occurred via a non-specific process (e.g. adsorptive pinocytosis).
Food
Michael R
MR
The Heart Research Institute, The Iron Metabolism and Chelation Group, Camperdown, Sydney, New South Wales, Australia.
Des Richardson
R
R
D000951:Antigens, Neoplasm; D001665:Binding Sites; D001667:Binding, Competitive; D006801:Humans; D007501:Iron / Q000378:metabolism / Q000493:pharmacokinetics*; D008545:Melanoma / Q000378:metabolism*; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014168:Transferrin / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D014168:Transferrin; D007501:Iron