Foster D A, Hanafusa H
J Virol. 1983 Dec;48(3):744-51. doi: 10.1128/JVI.48.3.744-751.1983.
From molecularly cloned DNAs of Fujinami sarcoma virus (FSV) and the Schmidt-Ruppin-A strain of Rous sarcoma virus (SRA), viral DNA was constructed in which fps-specific sequences encoded in FSV replaced the src gene of SRA. A 3' fragment of FSV DNA, from an ATG methionine coding sequence 148 base pairs downstream from the gag-fps junction through the long terminal repeat, was joined to cloned SRA DNA at the translation start site for the src gene. The resultant DNA clone contained the splice acceptor site for src mRNA processing in SRA, but contained no src coding sequences from SRA nor any gag sequences from FSV. All genes for the replication of SRA were retained. Transfection of this cloned viral DNA genome into chicken embryo fibroblasts induced morphological transformation of the cells in culture. However, the morphology of the transformed cells was distinct from that observed in cells infected with wild-type FSV. The transformed cells produced a nondefective transforming virus called F36 which contained a hybrid FSV-SRA long terminal repeat. F36-infected cells produced a protein with the expected molecular weight of 91,000, which had an associated protein kinase activity and was immunoprecipitated by antibodies raised against fps gene determinants but not by antibodies raised against gag or src proteins. Injection of F36 virus into 8-day-old chicks produced tumors at the site of inoculation, detectable within 7 days. These results demonstrated that the gag portion of the gag-fps fusion protein of FSV is not required for transformation or tumorigenesis.
从 Fujinami 肉瘤病毒（FSV）和劳斯肉瘤病毒施密特 - 鲁平 A 株（SRA）的分子克隆 DNA 构建了病毒 DNA，其中 FSV 编码的 fps 特异性序列取代了 SRA 的 src 基因。FSV DNA 的一个 3' 片段，从 gag - fps 连接处下游 148 个碱基对的 ATG 甲硫氨酸编码序列开始，穿过长末端重复序列，在 src 基因的翻译起始位点与克隆的 SRA DNA 连接。所得的 DNA 克隆包含 SRA 中 src mRNA 加工的剪接受体位点，但不包含 SRA 的 src 编码序列，也不包含 FSV 的任何 gag 序列。保留了 SRA 复制所需的所有基因。将这种克隆的病毒 DNA 基因组转染到鸡胚成纤维细胞中，可诱导培养细胞发生形态转化。然而，转化细胞的形态与感染野生型 FSV 的细胞中观察到的形态不同。转化细胞产生一种无缺陷的转化病毒，称为 F36，它含有杂交的 FSV - SRA 长末端重复序列。F36 感染的细胞产生一种预期分子量为 91,000 的蛋白质，该蛋白质具有相关的蛋白激酶活性，并且被针对 fps 基因决定簇产生的抗体免疫沉淀，但不被针对 gag 或 src 蛋白产生的抗体免疫沉淀。将 F36 病毒注射到 8 日龄雏鸡中，在接种部位产生肿瘤，7 天内即可检测到。这些结果表明，FSV 的 gag - fps 融合蛋白的 gag 部分对于转化或肿瘤发生不是必需的。
