HIGH-YIELD TRAPPING OF EGF-INDUCED RECEPTOR DIMERS BY CHEMICAL CROSS-LINKING
HIGH-YIELD TRAPPING OF EGF-INDUCED RECEPTOR DIMERS BY CHEMICAL CROSS-LINKING
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DOI：
10.1096/fasebj.3.1.2783412
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发表时间：
1989-01-01
期刊：
影响因子：
4.8
通讯作者：
STAROS, JV
中科院分区：
文献类型：
--
作者：
FANGER, BO;STEPHENS, JE;STAROS, JV
表皮生长因子 (EGF) 与其质膜受体的结合会刺激酪氨酰残基特异性蛋白激酶，该激酶已被证明是受体的一部分。 EGF 结合引起激酶活性刺激的机制尚不清楚；然而，最近的一些研究表明该过程中存在受体二聚化或寡聚化。我们制备了 A431 细胞的 Triton X-100 提取物，其中 EGF 受体的浓度约为 10-7 M。当提取物样品与或不与 EGF 一起孵育，然后用高产交联剂双(磺基琥珀酰亚胺基)辛二酸酯 (BS3) 处理时，在用 EGF 和 BS3 处理的样品中可以高产率检测到共价受体二聚体，而在用 EGF 和 BS3 处理的样品中仅检测到单体受体。未处理的样品或已用 EGF 或 BS3 处理的样品。通过交联捕获的受体二聚体的产量与 EGF 对自身磷酸化的刺激以及存在的 EGF 浓度相关。 EGF 诱导的受体二聚体在高度纯化的受体制剂中也能有效交联，这表明 EGF 诱导的二聚化是受体固有的过程，不需要额外的辅助蛋白。
The binding of epidermal growth factor (EGF) to its plasma membrane receptor results in the stimulation of a tyrosyl residue-specific protein kinase, which has been shown to be part of the receptor. The mechanism by which EGF binding gives rise to the stimulation of kinase activity is not understood in detail; however, a number of recent studies have implicated receptor dimerization or oligomerization in this process. We prepared Triton X-100 extracts of A431 cells in which the concentration of EGF receptors was on the order of 10-7 M. When samples of the extracts were incubated with or without EGF and then treated with the high-yield cross-linking reagent bis(sulfosuccinimidyl)suberate (BS3), covalent receptor dimers could be detected in high yield in samples that had been treated with both EGF and BS3, whereas only monomeric receptor was detected in untreated samples or in samples that had been treated with either EGF or BS3. The yield of receptor dimers trapped by cross-linking correlated with the stimulation of autophosphorylation by EGF and with the concentration of EGF present. EGF-induced receptor dimers were also efficiently cross-linked in highly purified receptor preparations, suggesting that EGF-induced dimerization is a process intrinsic to the receptor, requiring no additional accessory proteins.