头皮结构突出显示了相互交织的光环在胆固醇检测中的关键作用
Daniel L Kober1, Arun Radhakrishnan2, Joseph L Goldstein2
1Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Cell
|June 17, 2021
概括
固醇调节元素结合蛋白 (SREBP) 途径调节胆固醇的合成. 研究人员使用冷电子显微镜揭示了Scap蛋白质结构的变化,阻止了SREBP的运输和胆固醇的产生.
科学领域:
- 分子生物学
- 细胞生物学
- 结构生物学
背景情况:
- 胆固醇平衡对于细胞功能至关重要.
- 通过运输SREBP转录因子,Scap蛋白促进胆固醇的合成.
- 胆固醇水平通过Scap和Insig的相互作用来调节SREBP的运输.
研究的目的:
- 阐明Scap介导的SREBP运输的结构机制.
- 了解胆固醇如何与Scap结合,从而抑制其功能.
- 研究Scap-Insig相互作用在调节胆固醇合成中的结构基础.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定高分辨率结构.
- 在没有和存在Insig的情况下解决了全长的Scap结构.
- 结构分析的重点是Scap的光环与固醇感应域之间的相互作用.
主要成果:
- 皮的光环 (L1和L7) 形成一个球状域,连接到固醇感应域.
- 已知与L1结合的胆固醇可以抑制Scap的运输.
- Insig结合会导致显著的形状变化,包括L1-L7域的旋转和跨膜螺旋的重新排列.
结论:
- 交织在一起的L1-L7域作为Scap功能至关重要的平台.
- 这可能会阻止SREBP的传输.
- 这些发现为Scap-Insig途径对胆固醇合成的调节提供了结构性见解.
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