在与EGF受体结合的生长因子中负合作性的结构基础
Diego Alvarado1, Daryl E Klein, Mark A Lemmon
1Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6059, USA.
Cell
|August 21, 2010
概括
皮表皮生长因子受体 (EGFR) 结合表现出负合作性,其中第一个配体结合减少了随后结合的亲和力. 这解释了细胞表面EGF受体的特征和独特的信号特性.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 细胞信号传递 细胞信号传递
背景情况:
- 通过表皮生长因子受体 (EGFR) 传递超膜信号对于细胞生长和分化至关重要.
- EGFR信号传递涉及其细胞内氨酸激酶域的联结体诱导的二分化和全调节.
- 以前的晶体学研究解释了细胞外二分化,但没有观察到高和低亲和力EGF结合点.
研究的目的:
- 为了阐明细胞表面EGF受体结合中观察到的曲线Scatchard图的结构基础.
- 为了解释高和低亲和度EGF结合点的现象.
- 了解与EGFR结合的负合作性连接体的机制.
主要方法:
- 对Drosophila EGFR细胞外区域的一系列晶体结构的分析.
- 研究在初始连接器结合后的联结体诱导的二分化和结构变化.
- 结构分析不对称的二聚体形成及其对后续联结体亲和力的影响.
主要成果:
- 证明了Scatchard图形曲线的结果是负合作性连接体结合.
- 表明第一个联结结合会诱导一个不对称的二元体与一个结合的联结体.
- 确定了不对称二聚体中未被占用的结合部位在结构上受到限制,从而降低了对第二个连接体的亲和力.
结论:
- 该研究解释了EGF受体的细胞表面结合特征,包括曲的Scatchard图.
- 负合作性源于在初始连接键结合后形成的不对称二元体中的结构约束.
- 研究结果表明,不同的EGFR配体可以稳定不同的二维物种,其信号结果各不相同.
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