Simovich Marcia J, Conrad Marcel E, Umbreit Jay N, Moore Elizabeth G, Hainsworth Lucille N, Smith Hilary K
University of South Alabama, Mobile, Alabama, USA.
Am J Hematol. 2002 Mar;69(3):164-70. doi: 10.1002/ajh.10052.
K562 erythroleukemia cells and IEC6 rat cells were examined using confocal microscopy and antibodies raised against DMT-1 (Nramp-2, DCT-1), transferrin receptor (CD71), beta(3) integrin (CD61), mobilferrin (calreticulin), and Hephaestin. The cellular location of each of these proteins was identified by immunofluorescence in both saponin-permeabilized and non-permeabilized cells. Fluorescent reactivity was observed on or near the cell surface of each of these proteins, suggesting that they might participate in surface membrane transport of iron. Fluorescence was observed in the region of the cytoplasm with each antibody to include beta(3) integrin and transferrin receptor. It was pronounced in cells incubated with mobilferrin, Hephaestin, and DMT-1 antibodies. Speckled nuclear fluorescence was observed in cells incubated with anti-DMT-1. While these observations are descriptive, they demonstrate that there are significant concentrations of DMT-1, mobilferrin, and Hephaestin in the cytoplasmic region of cells. This suggests that there may be intracellular roles for these proteins in addition to their serving to transit iron across the cell surface membrane.
使用共聚焦显微镜和针对二价金属离子转运体1（Nramp-2、DCT-1）、转铁蛋白受体（CD71）、β3整合素（CD61）、钙网蛋白和铁转运辅助蛋白的抗体对K562红白血病细胞和IEC6大鼠细胞进行了检测。通过免疫荧光在皂素通透和非通透细胞中确定了这些蛋白质各自的细胞定位。在这些蛋白质各自的细胞表面或其附近观察到荧光反应性，表明它们可能参与铁的表面膜转运。用每种抗体在细胞质区域均观察到荧光，包括β3整合素和转铁蛋白受体。在用钙网蛋白、铁转运辅助蛋白和二价金属离子转运体1抗体孵育的细胞中荧光明显。在用抗二价金属离子转运体1抗体孵育的细胞中观察到斑点状核荧光。虽然这些观察结果只是描述性的，但它们表明在细胞的细胞质区域存在大量的二价金属离子转运体1、钙网蛋白和铁转运辅助蛋白。这表明这些蛋白质除了有助于铁穿过细胞表面膜转运外，在细胞内可能还有其他作用。
