Bister K, Ramsay G, Hayman M J, Duesberg P H
Proc Natl Acad Sci U S A. 1980 Dec;77(12):7142-6. doi: 10.1073/pnas.77.12.7142.
The RNA of defective avian acute leukemia virus OK10 was isolated from a defective virus particle, released by OK10-transformed nonproducer avian fibroblasts, as a 60S complex consisting of 8.6-kilobase subunits. Oligonucleotide fingerprinting and RNA.cDNA hybridization identified two sets of sequences in OK10 RNA: group-specific sequences, which are related to all nondefective members of the avian tumor virus group, and a sequence closely related to the subgroup-specific sequences (mcv) of the myelocytomatosis virus (MC29) subgroup of avian acute leukemia viruses. Hence, OK10 is classified as a member of the MC29 subgroup of avian tumor viruses, in agreement with classification based on its oncogenic spectrum. The group-specific sequences of OK10 RNA include partial (Delta) pol and env genes, a c-region, and, unlike those of all other members of the MC29 subgroup, a complete gag gene. Oligonucleotide mapping revealed 5'-gag-Deltapol-mcv-Deltaenv-c-3' as the order of the subgroup-specific and group-specific elements of OK10 RNA. The genetic unit gag-Deltapol-mcv, measuring approximately 6.4 kilobases, codes for the nonstructural, presumably transforming, 200,000-dalton OK10-specific protein and also includes the gag gene coding for the internal virion proteins. Because gag is the only intact virion gene shared in addition to regulatory RNA sequences between OK10 and nondefective avian tumor viruses, it is concluded that the gag gene is sufficient for the formation of a defective virus particle. Comparisons among the RNAs and gene products of different viruses of the MC29 subgroup show that they share 5'-terminal gag-related and internal mcv sequences but differ from each other in intervening gag-, pol-, and mcv-related sequences. It follows that the probable transforming genes and their protein products have two essential domains, one consisting of conserved 5' gag-related and the other of 3' mcv-related sequence elements. In the light of this and previous knowledge we can now distinguish two designs among five different transforming onc genes of avian tumor viruses: onc genes with coding sequences unrelated to virion genes, like those of Rous sarcoma virus and avian myeloblastosis virus, and onc genes with coding sequences that are hybrids of virion genes and specific sequences, like those of the MC29 subgroup viruses, of avian erythroblastosis virus, and of Fujinami sarcoma virus.
缺陷型禽急性白血病病毒OK10的RNA是从由OK10转化的非生产性禽成纤维细胞释放的缺陷病毒颗粒中分离出来的，它以由8.6千碱基亚基组成的60S复合物形式存在。寡核苷酸指纹图谱和RNA-cDNA杂交鉴定出OK10 RNA中的两组序列：组特异性序列，与禽肿瘤病毒组的所有非缺陷成员相关；以及与禽急性白血病病毒髓细胞瘤病毒（MC29）亚组的亚组特异性序列（mcv）密切相关的序列。因此，OK10被归类为禽肿瘤病毒MC29亚组的成员，这与基于其致癌谱的分类一致。OK10 RNA的组特异性序列包括部分（Δ）pol和env基因、一个c区，并且与MC29亚组的所有其他成员不同的是，还包括一个完整的gag基因。寡核苷酸图谱显示5'-gag-Δpol-mcv-Δenv-c-3'是OK10 RNA的亚组特异性和组特异性元件的顺序。遗传单元gag-Δpol-mcv约6.4千碱基，编码非结构的、可能具有转化作用的200,000道尔顿的OK10特异性蛋白，并且还包括编码病毒粒子内部蛋白的gag基因。由于gag是OK10与非缺陷型禽肿瘤病毒除调控RNA序列外唯一共享的完整病毒粒子基因，因此得出结论，gag基因足以形成缺陷病毒颗粒。对MC29亚组不同病毒的RNA和基因产物的比较表明，它们共享5'-末端gag相关和内部mcv序列，但在中间的gag-、pol-和mcv相关序列上彼此不同。由此可见，可能的转化基因及其蛋白质产物有两个基本结构域，一个由保守的5' gag相关序列组成，另一个由3' mcv相关序列元件组成。鉴于此及先前的知识，我们现在可以在禽肿瘤病毒的五个不同转化致癌基因中区分出两种设计：编码序列与病毒粒子基因无关的致癌基因，如劳氏肉瘤病毒和禽成髓细胞瘤病毒的致癌基因；以及编码序列是病毒粒子基因和特定序列杂交体的致癌基因，如MC29亚组病毒、禽成红细胞增多症病毒和藤浪肉瘤病毒的致癌基因。
