BIOSYNTHESIS AND GLYCOSYLATION OF THE EPIDERMAL GROWTH-FACTOR RECEPTOR IN HUMAN TUMOR-DERIVED CELL-LINES A431 AND HEP
BIOSYNTHESIS AND GLYCOSYLATION OF THE EPIDERMAL GROWTH-FACTOR RECEPTOR IN HUMAN TUMOR-DERIVED CELL-LINES A431 AND HEP
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DOI：
10.1128/mcb.6.1.257
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发表时间：
1986-01-01
影响因子：
5.3
通讯作者：
KNOWLES, BB
中科院分区：
文献类型：
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作者：
CARLIN, CR;KNOWLES, BB
在两种人类肿瘤来源的细胞系 Hep-3B 和 A431 中研究了表皮生长因子受体的生物合成。当衣霉素存在下生长时，两种细胞均表达受体相关物质 p135，即细胞表面表达的受体成熟形式 gp165 的生物合成前体 gp145 的假定非糖基化形式。当用衣霉素处理 A431 细胞（而非 Hep 3B）时，检测到另外两种受体相关物种：p115 和 p70。此外，用内切糖苷酶 F 消化 A431 受体相关蛋白导致检测到这三种非糖基化物质。 P70 似乎是 gp95 的无糖基化形式，gp95 是受体相关物种 gp120 的假定细胞内前体，由 A431 细胞而非 Hep-3B 细胞分泌； gp120 具有复杂的 N 连接糖基化模式，从而导致分子量和电荷异质性。 P115 可能是第三种生物合成中间体的非糖基化形式，可能是在脉冲追踪标记的早期时间点检测到的 gp135 种类。或者，p115和gp135可以分别通过Ca 2+ 介导的蛋白水解从p135和gp145共翻译或翻译后衍生。讨论了该分子生物合成的复杂性对于它为细胞提供调节细胞增殖的多种机会的影响。
Biosynthesis of the receptor for epidermal growth factor was investigated in two human tumor-derived cell lines, Hep-3B and A431. When growth in the presence of tunicamycin, both cells expressed a receptor-related species p135, the presumptive aglycosylated form of the biosynthetic precursor, gp145, of the mature form of the receptor, gp165, expressed at the cell surface. Two additional receptor-related species, p115 and p70, were detected when A431, but not Hep 3B, cells were treated with tunicamycin. Furthermore, digestion of the A431 receptor-related proteins with endoglycosidase F resulted in the detection of these three aglycosylated species. P70 appears to be the aglycosylated form of gp95, the presumptive intracellular precursor of the receptor-related species gp120 that is secreted by A431 but not Hep-3B cells; gp120 has a complex pattern of N-linked glycosylation, with consequent molecular weight and charge heterogeneity. P115 may be the aglycosylated form of a third biosynthetic intermediate, possibly a gp135 species detected in the early time points of pulse-chase labeling. Alternatively, p115 and gp135 may be derived co- or post-translationally by Ca2+-mediated proteolysis from p135 and gp145, respectively. The implications of the complexity of the biosynthesis of this molecule with regard to the multiple opportunities it affords the cell to modulate cell proliferation are discussed.