Blomberg J, Van de Ven W J, Reynolds F H, Nalewaik R P, Stephenson J R
J Virol. 1981 Jun;38(3):886-94. doi: 10.1128/JVI.38.3.886-894.1981.
Cells nonproductively transformed by a variant of the Snyder-Theilen strain of feline sarcoma virus (FeSV) expressed an 85,000-dalton polyprotein (P85) with associated tyrosine-specific protein kinase activity. We identified within this polyprotein a single tyrosine acceptor site for its enzyme activity. This acceptor site, as well as two serine phosphorylation sites localized with the p12 structural component of Snyder-Theilen FeSv P85, was phosphorylated in cells nonproductively transformed by Snyder-Theilen FeSv. In contrast, infection by Snyder-Theilen FeSV transformation-defective mutants resulted in phosphorylation only of the two serine acceptor sites, indicating phosphorylation of the tyrosine acceptor site to be transformation specific. In addition, we describe in vitro labeling conditions, using unfractionated cell extracts, which resulted in preferential phosphorylation of the single Snyder-Theilen FeSV tyrosine-specific acceptor site.
被猫肉瘤病毒（FeSV）的斯奈德 - 泰伦毒株变体非生产性转化的细胞表达了一种85,000道尔顿的多聚蛋白（P85），具有相关的酪氨酸特异性蛋白激酶活性。我们在这种多聚蛋白中鉴定出其酶活性的单个酪氨酸受体位点。该受体位点以及位于斯奈德 - 泰伦FeSv P85的p12结构成分中的两个丝氨酸磷酸化位点，在被斯奈德 - 泰伦FeSv非生产性转化的细胞中被磷酸化。相比之下，斯奈德 - 泰伦FeSV转化缺陷型突变体的感染仅导致两个丝氨酸受体位点的磷酸化，表明酪氨酸受体位点的磷酸化具有转化特异性。此外，我们描述了使用未分级细胞提取物的体外标记条件，该条件导致斯奈德 - 泰伦FeSV单个酪氨酸特异性受体位点的优先磷酸化。
