Heimann B, Beimling P, Pfaff E, Schaller H, Moelling K
Exp Cell Res. 1985 Nov;161(1):199-208. doi: 10.1016/0014-4827(85)90504-x.
The transforming protein erbB of avian erythroblastosis virus (AEV) has considerable sequence homology with the epidermal growth factor (EGF) and appears to represent a truncated form of this receptor. The sequence of the erbB gene is furthermore related to that of other viral transforming genes such as src, fps, yes or abl. The transforming proteins of these src-related oncogenes as well as receptors for EGF, platelet-derived growth factor (PDGF), and insulin are associated with tyrosine-specific protein kinases. It has been difficult to demonstrate this activity for the erbB protein. To analyze the erbB gene product, we prepared polyclonal antibodies against a bacterially expressed erbB DNA restriction fragment (BamHI/BamHI). The antiserum is shown to immunoprecipitate the erbB protein from AEV-transformed chicken fibroblasts and also recognizes the EGF receptor protein. Both proteins become phosphorylated in vitro on tyrosine residues upon the addition of [gamma-32P]ATP. The protein kinase activity is low compared to other oncogene-specific kinases. This is not due to kinase blocking by the serum, because erbB carboxyterminal synthetic peptide antibodies give rise to low levels of protein kinase activity as well indicating that this may be a characteristic property of erbB in vitro.
禽成红细胞增多症病毒（AEV）的转化蛋白erbB与表皮生长因子（EGF）具有相当程度的序列同源性，似乎代表了该受体的截短形式。此外，erbB基因的序列与其他病毒转化基因如src、fps、yes或abl的序列相关。这些与src相关的癌基因的转化蛋白以及EGF、血小板衍生生长因子（PDGF）和胰岛素的受体都与酪氨酸特异性蛋白激酶相关。一直以来都很难证明erbB蛋白具有这种活性。为了分析erbB基因产物，我们制备了针对细菌表达的erbB DNA限制片段（BamHI/BamHI）的多克隆抗体。该抗血清可从AEV转化的鸡成纤维细胞中免疫沉淀erbB蛋白，并且还能识别EGF受体蛋白。在加入[γ-32P]ATP后，这两种蛋白在体外酪氨酸残基上都会发生磷酸化。与其他癌基因特异性激酶相比，其蛋白激酶活性较低。这并非由于血清对激酶的阻断，因为erbB羧基末端合成肽抗体也会产生低水平的蛋白激酶活性，这表明这可能是erbB在体外的一个特性。
