PHOSPHORYLATION OF GAP AND GAP-ASSOCIATED PROTEINS BY TRANSFORMING AND MITOGENIC TYROSINE KINASES
PHOSPHORYLATION OF GAP AND GAP-ASSOCIATED PROTEINS BY TRANSFORMING AND MITOGENIC TYROSINE KINASES
复制标题
DOI：
10.1038/343377a0
复制
发表时间：
1990-01-25
期刊：
影响因子：
64.8
通讯作者：
PAWSON, T
中科院分区：
文献类型：
--
作者：
ELLIS, C;MORAN, M;PAWSON, T
蛋白酪氨酸激酶诱导细胞增殖和恶性转化的关键途径还没有很好的确定。由于微量注射抗p21ras抗体可以阻断正常和致癌酪氨酸激酶的生物学效应，它们可能需要有功能的p21ras来传递其有丝分裂信号1，2。然而，酪氨酸激酶和p21ras之间尚未建立生化联系。我们已经确定了胞质酪氨酸激酶的一个非催化结构域SH2，它调节着该蛋白结构域3-9的活性和特异性。在p21rasGTP酶激活蛋白(GAP)6，10，11中存在两个相邻的SH2结构域，这表明GAP可能直接与酪氨酸激酶相互作用。在这里，我们证明了GAP和两个相对分子质量为62,000和190,000的共沉淀蛋白(p62和p190)在被细胞质和受体样酪氨酸激酶转化的细胞中被酪氨酸磷酸化。这些多肽的磷酸化与表达v-srcorv-fpsen编码的酪氨酸激酶的诱导形式的细胞中的转化相关。此外，在表皮生长因子刺激的成纤维细胞中，GAP、p62和p190也被酪氨酸迅速磷酸化。我们的结果提示，酪氨酸激酶可以改变p21ras的功能，并使GAP及其相关蛋白成为具有酪氨酸激酶活性的癌蛋白和正常生长因子受体的靶标。这些数据支持SH2序列指导参与信号转导的细胞质蛋白相互作用的想法4-6。
THE critical pathways through which protein-tyrosine kinases induce cellular proliferation and malignant transformation are not well defined. As microinjection of antibodies against p21rascan block the biological effects of both normal and oncogenic tyrosine kinases, it is likely that they require functional p21rasto transmit their mitogenic signals1,2. No biochemical link has been established, however, between tyrosine kinases and p21ras. We have identified a non-catalytic domain of cytoplasmic tyrosine kinases, SH2, that regulates the activity and specificity of the kinase domain3–9. The presence of two adjacent SH2 domains in the p21rasGTPase-activating protein (GAP)6,10,11indicates that GAP might interact directly with tyrosine kinases. Here we show that GAP, and two co-precipitating proteins of relative molecular masses 62,000 and 190,000 (p62 and p190) are phosphorylated on tyrosine in cells that have been transformed by cytoplasmic and receptor-like tyrosine kinases. The phosphorylation of these polypeptides correlates with transformation in cells expressing inducible forms of thev-srcorv-fpsencoded tyrosine kinases. Furthermore, GAP, p62 and p190 are also rapidly phosphorylated on tyrosine in fibroblasts stimulated with epidermal growth factor. Our results suggest a mechanism by which tyrosine kinases might modify p21rasfunction, and implicate GAP and its associated proteins as targets of both oncoproteins and normal growth factor receptors with tyrosine kinase activity. These data support the idea4–6that SH2 sequences direct the interactions of cytoplasmic proteins involved in signal transduction.