SH2 domain proteins as high-affinity receptor tyrosine kinase substrates.
SH2 domain proteins as high-affinity receptor tyrosine kinase substrates.
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SH2 结构域蛋白作为高亲和力受体酪氨酸激酶底物。
DOI：
10.1021/bi00089a028
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Koland,JG
中科院分区：
文献类型：
--
作者：
Sierke,SL;Koland,JG
修订稿于 1993 年 6 月 17 日收到* 摘要：生长因子受体酪氨酸激酶 (RTK) 的激活伴随着受体酪氨酸残基的快速自磷酸化。受体激活已被证明可以促进含有 SH2 结构域（src 同源性的第二个结构域）的信号转导蛋白的关联。这些受体相关蛋白反过来可以被 RTK 磷酸化，这一事件可能调节它们的活性。有人建议，信号转导蛋白中的 SH2 结构域将这些蛋白作为激活 RTK 的底物。为了检验这一假设，生成了含有 erbB3 受体酪氨酸磷酸化位点和/或 c-src 的 SH2 结构域的重组蛋白。 SH2 结构域的掺入导致底物的 Km 降低和 VmiX 增加。确定的一种嵌合 SH2/erbB3 底物的 Km 是表皮生长因子 RTK 底物报道的最低值之一。使用缺乏 C 端自磷酸化位点的截短激酶进行的实验表明，这些底物的 Km 降低是通过底物 SH2 结构域和 RTK 的磷酸酪氨酸残基之间的相互作用介导的。这些相互作用也可能抑制 RTK 活性。这些结果证明SH2结构域可以有效地将底物靶向RTK，并且SH2结构域蛋白可以调节RTK活性。现已表征具有内在蛋白酪氨酸激酶活性的多种多肽生长因子受体。这些包括表皮生长因子 (EGF1)、血小板源性生长因子 (PDGF) 和胰岛素的受体，以及某些原癌基因产物，例如 c-kit（干细胞因子受体）和 c-fms（巨噬细胞集落刺激因子受体）（Cadena & Gill，1992；Yarden & Ullrich，1988）。这些受体激活的信号转导途径多种多样，并涉及其他
Revised Manuscript Received June 17, 1993* abstract: Activation of a growth factor receptor tyrosine kinase (RTK) is accompanied by a rapid autophosphorylation of the receptor on tyrosine residues. Receptor activation has been shown topromote the association of signal-transducing proteins containing SH2 domains (second domain of src homology). These receptor-associated proteins can, in turn, be phosphorylated by the RTK, an event which presumably regulates their activities. It has been suggested that SH2 domains in signal-transducing proteins target these proteins as substrates of the activated RTK. To test this hypothesis, recombinant proteins were generated that contained tyrosine phosphorylation sites of the erbB3 receptor and/or the SH2 domain of c-src. Incorporation of the SH2 domain led to a decrease in Km and an increase in VmiX for the substrate. The Km determined for one chimeric SH2/erbB3 substrate was among the lowest reported for epidermal growth factor RTK substrates. Experiments with a truncated kinase lackingC-terminal autophosphorylation sites indicated that the reduction in Km for these substrates was mediated by interactions between the substrate SH2 domain and phosphotyrosine residues of the RTK. These interactions could also inhibit RTK activity. These results demonstrate that the SH2 domain can effectively target substrates to a RTK and that SH2 domain proteins can regulate RTK activity.A variety of polypeptide growth factor receptors that possess intrinsic protein tyrosine kinase activity have now been characterized. These include the receptors for epidermal growth factor (EGF1), platelet-derived growth factor (PDGF) and insulin, and also certain protooncogene products, such as c-kit (the stem cell factor receptor) and c-fms (the macrophage colony-stimulating factor receptor)(Cadena &Gill, 1992; Yarden & Ullrich, 1988). The signal transduction pathways activated by these receptors are diverse and involve other