Robertson M A, Etchison J R, Robertson J S, Summers D F, Stanley P
Cell. 1978 Mar;13(3):515-26. doi: 10.1016/0092-8674(78)90325-2.
The carbohydrate moieties of the G glycoprotein of vesicular stomatitis virus (VSV) grown in three distinct lectin-resistant (LecR) Chinese hamster ovary (CHO) cell lines have been compared by fine structural analysis of radiolabeled glycopeptides. The mutant WgaRIII, selected for resistance to wheat germ agglutinin (WGA), produces VSV containing G glycoprotein specifically lacking in sialic acid. The mutant PhaRI, selected for resistance to phytohemagglutinin (PHA) and previously shown to lack a particular glycoprotein N-acetyl-glucosaminyl-transferase activity, produces VSV containing G glycoprotein specifically lacking terminal N-acetylglucosamine-galactose-sialic acid sequences and possessing an increased number of mannose residues in the "core" region of its carbohydrate moieties. The mutant PhaRIConARII, a "double" mutant selected from PhaRI cells for resistance to concanavalin A (ConA), produces VSV containing G glycoprotein with a further alteration in the mannose residues of the "core" oligosaccharide region. We discuss the relevance of these findings to the mechanisms of glycoprotein biosynthesis in mammalian cells and to the biochemical bases of lectin resistance in CHO cells.
通过对放射性标记糖肽的精细结构分析，比较了在三种不同的抗凝集素（LecR）中国仓鼠卵巢（CHO）细胞系中生长的水疱性口炎病毒（VSV）G糖蛋白的碳水化合物部分。选择对麦胚凝集素（WGA）具有抗性的突变体WgaRIII，其产生的VSV含有特异性缺乏唾液酸的G糖蛋白。选择对植物血凝素（PHA）具有抗性且先前已证明缺乏特定糖蛋白N-乙酰葡糖胺基转移酶活性的突变体PhaRI，其产生的VSV含有特异性缺乏末端N-乙酰葡糖胺-半乳糖-唾液酸序列且在其碳水化合物部分的“核心”区域具有增加数量甘露糖残基的G糖蛋白。从PhaRI细胞中选择的对刀豆球蛋白A（ConA）具有抗性的“双重”突变体PhaRIConARII，其产生的VSV含有在“核心”寡糖区域的甘露糖残基有进一步改变的G糖蛋白。我们讨论了这些发现与哺乳动物细胞中糖蛋白生物合成机制以及CHO细胞中凝集素抗性生化基础的相关性。
