Receptor-mediated endocytosis of transferrin and the uptake of fe in K562 cells: identification of a nonlysosomal acidic compartment.
Receptor-mediated endocytosis of transferrin and the uptake of fe in K562 cells: identification of a nonlysosomal acidic compartment.
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K562 细胞中转铁蛋白受体介导的内吞作用和 fe 的摄取：非溶酶体酸性区室的鉴定。
DOI：
10.1073/pnas.79.20.6186
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发表时间：
1982
影响因子：
11.1
通讯作者：
R. Klausner
中科院分区：
文献类型：
--
作者：
J. V. Renswoude;K. Bridges;J. Harford;R. Klausner
在生理温度下，铁载体转铁蛋白通过受体介导的内吞作用被K562人红白血病细胞吸收。配体（现在减去铁）和受体都循环回到细胞表面，在那里受体被迅速重新利用。根据荧光素异硫氰酸盐标记的转铁蛋白在37℃下与细胞相关的光谱特征和量子产率的变化来判断，在内吞作用后，转铁蛋白会暂时停留在细胞内的酸性隔间中。抗荧光素抗体强烈抑制蛋白上荧光素标记残基的发射，用于评估转铁蛋白是在细胞表面（0℃孵育）还是主要内化到细胞内（37℃孵育）。利用Percoll梯度分离核后上清，我们发现酸性区室不是溶酶体区室。
At physiological temperature, the Fe-carrier transferrin is taken up by K562 human erythroleukemia cells through receptor-mediated endocytosis. Both ligand (now minus Fe) and receptor recycle back to the cell surface where the receptor is rapidly reutilized. After endocytosis, transferrin becomes transiently lodged within an acidic compartment inside the cell, as judged by the changed spectral characteristics and quantum yield of fluorescein isothiocyanate-labeled transferrin that is cell-associated at 37 degrees C. Upon binding to transferrin, anti-fluorescein antibody strongly quenches the emission of the fluorescein-labeled residues on the protein and is used to assess whether the transferrin is at the cell surface (incubation at 0 degrees C) or mainly internalized into the cell (incubation at 37 degrees C). Using Percoll gradient fractionation of postnuclear supernatants, we show that the acidic compartment is not the lysosomal compartment.