Department of Biosystems Science and Engineering, ETH Zurich, CH-4058 Basel, Switzerland.
Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, CH-8093 Zurich, Switzerland.
Sci Signal. 2022 Jun 7;15(737):eabi7031. doi: 10.1126/scisignal.abi7031.
In cell membranes, G protein-coupled receptors (GPCRs) interact with cholesterol, which modulates their assembly, stability, and conformation. Previous studies have shown how cholesterol modulates the structural properties of GPCRs at ambient temperature. Here, we characterized the mechanical, kinetic, and energetic properties of the human β-adrenergic receptor (βAR) in the presence and absence of the cholesterol analog cholesteryl hemisuccinate (CHS) at room temperature (25°C), at physiological temperature (37°C), and at high temperature (42°C). We found that CHS stabilized various structural regions of βAR differentially, which changed nonlinearly with temperature. Thereby, the strongest effects were observed for structural regions that are important for receptor signaling. Moreover, at 37°C, but not at 25° or 42°C, CHS caused βAR to increase and stabilize conformational substates to adopt to basal activity. These findings indicate that the nonlinear, temperature-dependent action of CHS in modulating the structural and functional properties of this GPCR is optimized for 37°C.
在细胞膜中，G 蛋白偶联受体（GPCR）与胆固醇相互作用，胆固醇调节 GPCR 的组装、稳定性和构象。先前的研究表明胆固醇如何在环境温度下调节 GPCR 的结构特性。在这里，我们在室温（25°C）、生理温度（37°C）和高温（42°C）下，研究了胆固醇类似物胆甾醇半琥珀酸酯（CHS）存在和不存在的情况下，人β-肾上腺素能受体（βAR）的力学、动力学和能量特性。我们发现 CHS 以不同的方式稳定了βAR 的各种结构区域，这些区域随温度呈非线性变化。因此，对受体信号很重要的结构区域观察到最强的影响。此外，在 37°C 时，但在 25°C 或 42°C 时，CHS 导致 βAR 增加并稳定构象亚稳态以适应基础活性。这些发现表明，CHS 在调节这种 GPCR 的结构和功能特性方面的非线性、温度依赖性作用是针对 37°C 进行优化的。
