Biosynthesis and processing of fibronectin in NIL.8 hamster cells.
Biosynthesis and processing of fibronectin in NIL.8 hamster cells.
复制标题
NIL.8 仓鼠细胞中纤连蛋白的生物合成和加工。
DOI：
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发表时间：
1979
影响因子：
4.8
通讯作者：
R. Hynes
中科院分区：
文献类型：
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作者：
M. Choi;R. Hynes
纤连蛋白被合成为单体多肽链。早在细胞内就能检测到它时，它就带有碳水化合物侧链。这些链对糖苷内切酶 H 敏感，表明它们是天冬酰胺连接的高甘露糖形式。单体链仍在细胞内时迅速二聚。标记开始后约 30 分钟，新合成的纤连蛋白在细胞表面和分泌到培养基中均以二聚体形式出现。这种输出的纤连蛋白具有内切糖苷酶 H 抗性碳水化合物侧链，表明从高甘露糖形式加工成复杂形式。纤连蛋白在碳水化合物加工后迅速排出细胞外；细胞内不存在大量抗内切糖苷酶 H 的纤连蛋白。细胞表面的二聚体纤连蛋白最初是脱氧胆酸盐可溶的，但慢慢地变成脱氧胆酸盐不溶性的，并且还慢慢形成高分子量聚集体，需要还原二硫键才能解离。
Fibronectin is synthesized as a monomeric polypeptide chain. As early as it can be detected inside the cell, it carries carbohydrate side chains. These chains are sensitive to endoglycosidase H, suggesting that they are asparagine linked and high mannose form. The monomeric chains quickly dimerize while still inside the cell. Newly synthesized fibronectin appears as a dimer, both at the cell surface and secreted into the culture medium, about 30 min after commencement of labeling. This exported fibronectin has endoglycosidase H-resistant carbohydrate side chains, indicating processing from the high mannose form to a complex form. Exit of fibronectin to the outside of the cell follows quickly on carbohydrate processing; no large pool of endoglycosidase H-resistant fibronectin exists inside the cell. The dimeric fibronectin at the cell surface is initially deoxycholate soluble but slowly becomes deoxycholate-insoluble and also slowly forms high molecular weight aggregates which require reduction of disulfide bonds for their dissociation.