FUNCTIONAL-ANALYSIS OF THE LIGAND-BINDING SITE OF EGF-RECEPTOR UTILIZING CHIMERIC CHICKEN HUMAN RECEPTOR MOLECULES
FUNCTIONAL-ANALYSIS OF THE LIGAND-BINDING SITE OF EGF-RECEPTOR UTILIZING CHIMERIC CHICKEN HUMAN RECEPTOR MOLECULES
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DOI：
10.1002/j.1460-2075.1989.tb03393.x
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发表时间：
1989-02-01
期刊：
影响因子：
11.4
通讯作者：
SCHLESSINGER, J
中科院分区：
文献类型：
--
作者：
LAX, I;BELLOT, F;SCHLESSINGER, J
表皮生长因子（EGF）受体由细胞外配体结合区组成，通过单个跨膜区连接到细胞质激酶结构域。尽管它的重要性，了解信号转导，EGF受体的配体结合域尚未确定。我们描述了一个主要的配体结合结构域的EGF受体，利用嵌合体之间的人EGF受体和鸡EGF受体的识别。这种方法是基于鼠EGF结合鸡EGF受体的亲和力比人EGF受体低100倍的事实。因此，鸡EGF受体的各种结构域被人EGF受体的结构域取代可以恢复对EGF的较高结合亲和力，这是人受体的特征。我们表明，嵌合鸡/人EGF受体，其中包含的结构域III的胞外区的人受体，就EGF结合亲和力和生物反应性的行为像人EGF受体。然而，含有人受体的结构域I和II的嵌合鸡/人EGF受体的行为类似于鸡而不是人EGF受体。此外，竞争EGF与EGF受体结合的两种不同的单克隆抗体特异性识别人EGF受体的结构域III。可以得出结论，结构域III，这是侧翼的两个富含半胱氨酸的结构域是一个主要的配体结合域的EGF受体。
The epidermal growth factor (EGF)-receptor is composed of an extracellular ligand-binding region connected by a single transmembrane region to the cytoplasmic kinase domain. In spite of its importance for understanding signal transduction, the ligand-binding domain of the EGF-receptor is not yet defined. We describe the identification of a major ligand-binding domain of the EGF-receptor by utilizing chimeras between the human EGF-receptor and the chicken EGF-receptor. This approach is based on the fact that murine EGF binds to the chicken EGF-receptor with 100-fold lower affinity as compared to the human EGF-receptor. Hence, the substitution of various domains of the chicken EGF-receptor by domains of the human EGF-receptor may restore the higher binding affinity towards EGF, characteristic of the human receptor. We show that chimeric chicken/human EGF-receptor, which contains domain III of the extracellular region of the human receptor, behaves like the human EGF-receptor with respect to EGF binding affinity and biological responsiveness. However, a chimeric chicken/human EGF-receptor containing domains I and II of the human receptor behaves like the chicken rather than the human EGF-recetpor. Moreover, two different monoclonal antibodies which compete for the binding of EGF to EGF-receptor recognize specifically domain III of the human EGF-receptor. It is concluded that domain III which is flankded by the two cysteine-rich domains is a major ligand-binding domain of the EGF-receptor.