Linial M, Fenno J, Burnette W N, Rohrschneider L
J Virol. 1980 Oct;36(1):280-90. doi: 10.1128/JVI.36.1.280-290.1980.
We have studied the pattern of glycoprotein synthesis in two nonconditional mutants of Rous sarcoma virus. One mutant, SE33, produces no viral particles but synthesizes Pr92env, which is cleaved intracellularly to mature glycoproteins. The second mutant, SE521, encodes a gPr92env which is not cleaved to gp85 or gp37 and therefore produces virions with the phenotype of Bryan RSV(-) or NY8. Neither of these mutants have detectable genomic deletions. The study of these mutants has led to the following conclusions. (i) In the absence of particle production or p15 synthesis, gPr92env can be cleaved to the mature glycoprotein which is found on the cell surface. (ii) Noncleaved gPr92env is not packaged into virions but is found on the cell surface. (iii) gPr92env alone can account for subgroup specific viral interference. (iv) gPr92env is probably transported to the cell surface before additional glycosylation or cleavage to mature virion glycoprotein. The nonprocessed precursor of SE521 appears to be glycosylated normally, and thus far we have been unable to determine the basis for the defect in this mutant.
我们研究了劳氏肉瘤病毒的两个非条件突变体中糖蛋白的合成模式。一个突变体SE33不产生病毒颗粒，但能合成Pr92env，其在细胞内被切割成成熟的糖蛋白。第二个突变体SE521编码一种gPr92env，它不会被切割成gp85或gp37，因此产生具有Bryan RSV(-)或NY8表型的病毒粒子。这些突变体均未检测到基因组缺失。对这些突变体的研究得出了以下结论。(i) 在不产生病毒颗粒或不合成p15的情况下，gPr92env可被切割成细胞表面发现的成熟糖蛋白。(ii) 未切割的gPr92env不会被包装到病毒粒子中，而是存在于细胞表面。(iii) 单独的gPr92env可导致亚组特异性病毒干扰。(iv) gPr92env可能在进一步糖基化或切割成成熟病毒粒子糖蛋白之前就被转运到细胞表面。SE521的未加工前体似乎正常糖基化，到目前为止我们还无法确定该突变体缺陷的基础。
