Ligand-independent oncogenic transformation by the EGF receptor requires kinase domain catalytic activity.
Ligand-independent oncogenic transformation by the EGF receptor requires kinase domain catalytic activity.
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EGF 受体的配体依赖性致癌转化需要激酶结构域催化活性。
DOI：
10.1006/excr.2002.5494
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Maihle,NitaJ
中科院分区：
文献类型：
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作者：
Danielsen,AndrewJ;Maihle,NitaJ
逆转录病毒癌基因S3-v-erbB是禽类表皮生长因子(ErbB-1)受体的转导、截短形式。用表达S3-v-ErbB的逆转录病毒载体感染禽类成纤维细胞，可导致非配体依赖性的细胞转化，并伴随着转化特异性磷蛋白信号复合体的组装和非锚定依赖性的细胞生长。此前已报道，使用赖氨酸-721突变体(K721)，ErbB介导的细胞转化需要激活域功能。然而，自从这些最初的报道以来，一些使用天冬氨酸-813突变体(D813)的研究已经证明了激酶受损的ErbB受体以配体依赖的方式诱导有丝分裂信号转导通路和细胞转化的能力。为了确定ErbB受体激酶域催化活性在非配体依赖的细胞转化中的必要性，我们创建了S3-v-ErbB-K−，这是一种通过用丙氨酸(D813A)取代天冬氨酸-813构建的激酶受损的癌蛋白。S3-v-ErbB-K−突变受体的亚细胞路径以及细胞表膜和核定位不受激酶活性损伤的影响。相反，表达S3-v-ErbB-K−的禽类成纤维细胞在体外不能形成特有的转化特异性磷酸蛋白复合体，也不能诱导软琼脂集落生长。这些结果表明，与配体依赖的致癌信号相反，通过EGF受体的成分激活的突变形式进行的配体非依赖性细胞转化需要受体激酶催化活性。此外，这些结果表明，下游信号复合体的磷酸化和组装需要酪氨酸磷酸化事件，而酪氨酸磷酸化事件直接由致癌形式的EGF受体介导。
The retroviral oncogene S3-v-erbB is a transduced, truncated form of the avian EGF (ErbB-1) receptor. Infection of avian fibroblasts with a retroviral vector expressing S3-v-ErbB results in ligand-independent cell transformation, which is accompanied by the assembly of a transformation-specific phosphoprotein signaling complex and anchorage-independent cell growth. It previously had been reported, using lysine-721 mutants (K721), that kinase domain function was required for ErbB-mediated cell transformation. However, since these initial reports, several studies using aspartate-813 mutants (D813) have demonstrated the ability of kinase-impaired ErbB receptors to induce mitogenic signal transduction pathways and cell transformation in a ligand-dependent manner. To determine the necessity of ErbB receptor kinase domain catalytic activity in ligand-independent cell transformation, we created S3-v-ErbB-K−, a kinase-impaired oncoprotein constructed by replacing aspartate-813 with alanine (D813A). Subcellular routing as well as cell surface membrane and nuclear localization of the S3-v-ErbB-K−mutant receptor were unaffected by impairment of kinase activity. In contrast, avian fibroblasts expressing S3-v-ErbB-K−do not form the characteristic transformation-specific phosphoprotein complex, or induce soft agar colony growth in vitro. These results suggest that in contrast to ligand-dependent oncogenic signaling, ligand-independent cell transformation by a constitutively activated mutant form of the EGF receptor requires receptor kinase catalytic activity. In addition, these results demonstrate that phosphorylation and assembly of downstream signaling complexes require tyrosine phosphorylation events that are directly mediated by oncogenic forms of the EGF receptor.