胰岛素受体通过胰岛素样生长因子2的激活
Weidong An1, Catherine Hall2, Jie Li1
1Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
Nature communications
|March 24, 2024
概括
与胰岛素相比,胰岛素样生长因子2 (IGF2) 通过不同的机制激活胰岛素受体 (IR). 低温-EM结构揭示了IGF2与IR异型 (IR-A和IR-B) 的结合如何导致不对称激活,影响生长和新陈代谢.
科学领域:
- 分子和细胞生物学分子和细胞生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 胰岛素受体 (IR) 对于调节细胞生长和新陈代谢至关重要.
- 胰岛素样生长因子2 (IGF2) 通过结合IR模仿胰岛素的功能,但其激活机制尚未完全理解.
- 存在两种主要的IR异型,IR-A和IR-B,具有潜在不同的结合特性.
研究的目的:
- 阐明IGF2诱导的IR-A和IR-B异形激活的分子机制.
- 为了确定IGF2与IR异型的差异性结合亲和力的结构基础.
- 了解IGF2结合是如何影响红外线信号和细胞贩运的.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定红外异形的高分辨率结构.
- 不活跃和IGF2绑定的IR-A和IR-B的结构分析.
- 基于细胞的测试以验证IGF2-IR相互作用的功能影响.
主要成果:
- 低温-EM结构显示,与胰岛素诱导的对称形状不同,IGF2结合的IR-A和IR-B采用了不对称的形状.
- 与胰岛素相比,IGF2与IR上的两个位点 (位点-1和位点-2) 结合,在位点-2的亲和力相对较弱.
- IR-B的非活性状态涉及分子内接触,阻碍IGF2结合,影响结合率.
结论:
- 该研究揭示了IGF2激活胰岛素受体的结构机制,突出了不对称的形状.
- 由于IGF2与IR-A和IR-B的结合亲缘关系不同,可以通过结构差异和结合部位相互作用来解释.
- 了解IGF2-IR相互作用为代谢和生长调节提供了洞察力.
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