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Transferrin endocytosis and iron uptake in developing myogenic cells in culture: Effects of microtubular and metabolic inhibitors, sulphydryl reagents and lysosomotrophic agents
Author(s) -
Sorokin L. M.,
Morgan E. H.,
Yeoh G. C. T.
Publication year - 1988
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041370313
Subject(s) - endocytosis , transferrin , internalization , transferrin receptor , endosome , microbiology and biotechnology , biochemistry , receptor mediated endocytosis , biology , chemistry , receptor , intracellular
The experiments described in this study were designed to investigate receptor‐mediated endocytosis of transferrin and its role in iron uptake by cultured chick presumptive myoblasts (dividing and non‐dividing) and myotubes. The effects of a variety of inhibitors on the internalization of transferrin and iron were investigated and three main effects were found: (i) sulphydryl reagents and microtubular inhibitors reduced the rate of transferrin and iron internalization to similar degrees, (ii) metabolic inhibitors reduced the rate of iron uptake more than that of transferrin endocytosis, and (iii) lysosomotrophic agents almost completely abolished iron accumulation by the cells without any effect on the rate of transferrin internalization. The results suggest that metabolic energy is required not only for the endocytosis of transferrin but also for subsequent steps in the iron uptake process, and that iron release from transferrin occurs in acidified endosomes. Overall, these experiments show that all or virtually all of the iron taken up by developing muscle cells from transferrin occurs as a consequence of receptor‐mediated endocytosis of the protein.