Reynolds F H, Van de Ven W J, Blomberg J, Stephenson J R
J Virol. 1981 Jun;38(3):1084-9. doi: 10.1128/JVI.38.3.1084-1089.1981.
The Gardner and Snyder-Theilen isolates of feline sarcoma virus (FeSV) have previously been shown to encode high-molecular-weight polyproteins with a transforming function and an associated tyrosine-specific protein kinase activity. Cells transformed by these viruses exhibited morphological alterations, elevated levels of phosphotyrosine, and a reduced capacity for binding epidermal growth factor. In addition, polyproteins encoded by both of these FeSV isolates bound to, and phosphorylated tyrosine acceptor sites within, a 150,000-molecular-weight cellular substrate (P150). McDonough FeSV-transformed cells resembled Gardner and Snyder-Theilen FeSV transformants with respect to morphological changes and a reduced capacity for epidermal growth factor binding. in contrast to the other two FeSV isolates, however, McDonough FeSV encoded as its major translational product a high-molecular-weight polyprotein with probable transforming function but without protein kinase activity detectable under similar assay conditions. Moreover, total cellular levels of phosphotyrosine remained unaltered in McDonough FeSV-transformed cells, and the major McDonough FeSV polyprotein translational product lacked binding affinity for P150. These findings argue for differences in the mechanisms of transformation by these independently derived FeSV isolates.
先前已证明，加德纳猫肉瘤病毒（FeSV）和斯奈德-泰伦猫肉瘤病毒分离株可编码具有转化功能及相关酪氨酸特异性蛋白激酶活性的高分子量多聚蛋白。被这些病毒转化的细胞呈现出形态改变、磷酸酪氨酸水平升高以及结合表皮生长因子的能力降低。此外，这两种FeSV分离株编码的多聚蛋白均能结合并磷酸化一种分子量为150,000的细胞底物（P150）中的酪氨酸受体位点。麦克多诺FeSV转化的细胞在形态变化和表皮生长因子结合能力降低方面与加德纳和斯奈德-泰伦FeSV转化细胞相似。然而，与其他两种FeSV分离株不同的是，麦克多诺FeSV编码的主要翻译产物是一种具有可能转化功能的高分子量多聚蛋白，但在类似检测条件下未检测到蛋白激酶活性。此外，在麦克多诺FeSV转化的细胞中，磷酸酪氨酸的总细胞水平保持不变，并且麦克多诺FeSV主要多聚蛋白翻译产物对P150缺乏结合亲和力。这些发现表明这些独立衍生的FeSV分离株在转化机制上存在差异。
