Micropinocytosis of transferrin by developing red cells: an electron- microscopic study utilizing ferritin-conjugated transferrin and ferritin-conjugated antibodies to transferrin

作者：AL Sullivan, JA Grasso, LR Weintraub · 发表于：Blood · 年份：1976 · DOI：10.1182/blood.v47.1.133.133 · 被引用次数：121 · 研究领域：Erythrocyte Function and Pathophysiology、Lipid Membrane Structure and Behavior、RNA Interference and Gene Delivery

Electron-microscopic examination of rat reticulocytes and normoblasts incubated with transferrin conjugated to ferritin or ferritin-labeled antitransferrin revealed binding of ferritin conjugates to the surface membrane, and uptake of ferritin conjugates in micropinocytotic vesicles. No binding or endocytosis of ferritin was visualized when rat reticulocytes or normoblasts were incubated with ferritin alone or ferritin conjugated to nonspecific rabbit IgG. These observations support the concept that transferrin binds to a surface membrane receptor and is subsequently internalized by the developing red cell. Time course and temperature dependence studies suggest the endocytosis of transferrin may be an important mechanism in delivery of iron to the developing red cell.