Martin G S
Cancer Surv. 1986;5(2):199-219.
The epidermal growth factor (EGF) receptor is a plasma membrane glycoprotein. It contains four distinct segments: an N-terminal EGF binding domain which is exposed at the cell surface; a short transmembrane segment; a cytoplasmic domain with protein-tyrosine kinase activity; and a C-terminal regulatory segment. Binding of EGF to the external domain of the receptor activates the protein-tyrosine kinase activity of the receptor, and this elevated kinase activity is presumed to be involved in the activation of cell growth. The v-erbB transforming gene of avian erythroblastosis virus is derived, by retroviral transduction, from the gene (c-erbB) which encodes the avian EGF receptor. The transforming capacity of v-erbB appears to result from truncation of the receptor. In erythroid cells, truncation of the N-terminal ligand binding domain is sufficient for transformation, whereas in fibroblasts removal of an additional C-terminal segment is required for transformation. The EGF receptor is subject to complex regulatory controls, including ligand activation, downregulation by internalization, autophosphorylation and autoregulation and transmodulation involving phosphorylation by kinase C. This review is centered around the hypothesis that the transforming capacity of the truncated v-erbB gene product results from a loss in sensitivity to regulators and the consequent activation of protein kinase activity.
表皮生长因子（EGF）受体是一种质膜糖蛋白。它包含四个不同的区段：一个暴露于细胞表面的N端EGF结合结构域；一个短的跨膜区段；一个具有蛋白酪氨酸激酶活性的胞质结构域；以及一个C端调节区段。EGF与受体的外部结构域结合会激活受体的蛋白酪氨酸激酶活性，并且这种升高的激酶活性被认为与细胞生长的激活有关。禽成红细胞增多症病毒的v-erbB转化基因是通过逆转录病毒转导从编码禽EGF受体的基因（c-erbB）衍生而来的。v-erbB的转化能力似乎是由受体的截短导致的。在红细胞中，N端配体结合结构域的截短足以实现转化，而在成纤维细胞中，转化则需要去除额外的C端区段。EGF受体受到复杂的调控，包括配体激活、通过内化进行的下调、自身磷酸化和自身调节以及涉及蛋白激酶C磷酸化的转调节。本综述围绕这样一个假说展开，即截短的v-erbB基因产物的转化能力源于对调节因子敏感性的丧失以及随之而来的蛋白激酶活性的激活。
