一个简单的结构编码IGF-II/曼6酸盐受体的G蛋白激活功能
T Okamoto1, T Katada, Y Murayama
1Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Japan.
Cell
|August 24, 1990
概括
类似胰岛素的生长因子-II/曼诺6酸盐受体 (IGF-II/man6PR) 直接激活Gi-2G蛋白. 一个特定的受体段对于这种相互作用至关重要,类似于G蛋白结合受体.
科学领域:
- 细胞信号传递途径 细胞信号传递途径
- 与G蛋白结合的受体是G蛋白结合的受体.
- 受体-联结体相互作用
背景情况:
- 已知胰岛素样生长因子-II/曼诺-6酸盐受体 (IGF-II/man6PR) 与G蛋白相互作用.
- IGF-II/man6PR与G蛋白,特别是Gi-2的相互作用的精确机制需要进一步阐明.
研究的目的:
- 为了确定IGF-II/man6PR的特定区域,负责激活Gi-2G蛋白.
- 描述这个激活段的功能性质及其与各种G蛋白的相互作用.
- 确认这个段在受体的Gi-2激活功能中的关键作用.
主要方法:
- 来自人类IGF-II/man6PR.的特定部分 (残留物2410-2423) 的合成.
- 在体外测试试验测试该片段激活不同G蛋白 (Gi-1,Gi-2,Gi-3,Go,Gs) 和低分子量G蛋白的能力.
- 通过将其连接到受体跨膜区域的一部分来修改细分,以评估潜能.
- 使用针对特定部分的抗体阻止Gi-2激活的抑制试验.
主要成果:
- 人类IGF-II/man6PR的一个部分 (残留物2410-2423) 直接激活Gi-2 G蛋白.
- 该段的激活遵循一个层次结构:Gi-2 > Gi-1 ≈ Gi-3 > Go,对Gs或小G蛋白没有影响.
- 该片段的主要结构对其功能至关重要,当与受体的跨膜区域连接时,这种功能会得到增强.
- 对该段的抗体有效地阻止了IGF-II/man6PR的Gi-2激活功能.
结论:
- 在IGF-II/man6PR中,一个特定的氨基酸段直接负责激活Gi-2G蛋白.
- 这个部分模仿了G蛋白合受体在激活Gi-2中的功能.
- 被识别的部分在受体的信号通路中发挥着关键作用,突出显示了它在细胞通信中的重要性.
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