MORPHOLOGIC CHARACTERIZATION OF THE PATHWAY OF TRANSFERRIN ENDOCYTOSIS AND RECYCLING IN HUMAN KB CELLS
MORPHOLOGIC CHARACTERIZATION OF THE PATHWAY OF TRANSFERRIN ENDOCYTOSIS AND RECYCLING IN HUMAN KB CELLS
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DOI：
10.1073/pnas.81.1.175
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发表时间：
1984-01-01
期刊：
影响因子：
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通讯作者：
PASTAN, I
中科院分区：
文献类型：
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作者：
WILLINGHAM, MC;HANOVER, JA;PASTAN, I
在[表皮样癌] KB细胞中研究了转铁蛋白摄取和再循环的途径，以试图确定转铁蛋白返回细胞表面所涉及的细胞器。比较了与表皮生长因子（EGF），其终止于溶酶体的内化途径。将转铁蛋白的辣根过氧化物酶缀合物（TF-HRP）与KB细胞在4 ℃温育。在不同的时间后，升温至37 ℃。C.在EM水平上检测TF-HRP的定位。转铁蛋白，像EGF一样，通过被膜小凹进入细胞，并被发现移动到受体体（内体）的高尔基体区域。转铁蛋白位于高尔基体的transreticular部分的管状元件，但不是在高尔基体堆栈。有趣的是，转铁蛋白并不集中在高尔基体的被膜凹陷中。EGF的浓度非常高。接下来在管状元件中检测到转铁蛋白（600.在宽度和高达5，000埃。长度），与微管和哑铃形结构密切相关。与此相反，在这些结构中没有检测到EGF，这表明这些细胞器含有转铁蛋白，但不EGF，参与受体结合的转铁蛋白返回细胞表面。
The pathway of transferrin uptake and recycling was investigated in [epidermoid carcinoma] KB cells to attempt to identify the organelles involved in the return of transferrin to the cell surface. Comparison was made with the pathway of internalization of epidermal growth factor (EGF), which terminates in lysosomes. A horseradish peroxidase conjugate of transferrin (TF-HRP) was incubated with KB cells at 4.degree. C and, at various times after warming to 37.degree. C, the location of TF-HRP was examined at the EM level. Transferrin, like EGF, entered cells via coated pits and was found to move to the Golgi region in receptosomes (endosomes). Transferrin was located in the tubular elements of the transreticular portion of the Golgi but not in Golgi stacks. Interestingly, transferrin was not concentrated in the coated pits of the Golgi. In contrast, EGF was highly concentrated there. Transferrin was next detected in tubular elements (.apprxeq. 600 .ANG. in width and up to 5,000 .ANG. in length) that were closely associated with microtubules and in dumbbell-shaped structures. In contrast, EGF was not detected in these structures, suggesting that those organelles containing transferrin, but not EGF, participate in the return of receptor-bound transferrin to the cell surface.