Single-molecule imaging reveals receptor-G protein interactions at cell surface hot spots
Single-molecule imaging reveals receptor-G protein interactions at cell surface hot spots
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DOI：
10.1038/nature24264
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发表时间：
2017-10-26
期刊：
影响因子：
64.8
通讯作者：
Calebiro, Davide
中科院分区：
文献类型：
--
作者：
Sungkaworn, Titiwat;Jobin, Marie-Lise;Calebiro, Davide
g蛋白偶联受体介导许多激素和神经递质的生物学效应，是重要的药理学靶点(1)。它们通过与G蛋白相互作用将信号传递到细胞内部。然而，受体和G蛋白如何相遇、相互作用和偶联尚不清楚。在这里，我们分析了G蛋白偶联受体和G蛋白在质膜上的协同运动，并提供了一个定量模型，揭示了它们相互作用的高时空复杂性背后的关键因素。利用双色、单分子成像，我们可视化了活细胞表面单个受体和G蛋白之间的相互作用。在基本条件下，受体和G蛋白形成活性依赖复合物，持续约一秒。激动剂专门调节受体- g蛋白相互作用的动力学，主要是通过增加它们的关联率。我们在质膜上发现热点，至少部分由细胞骨架和网格蛋白包裹的凹坑定义，其中受体和G蛋白被限制并优先偶联。纳米体Nb37成像表明，g蛋白偶联受体的信号传导优先发生在这些热点。这些发现揭示了控制g蛋白偶联受体信号传导的动态相互作用。
G-protein-coupled receptors mediate the biological effects of many hormones and neurotransmitters and are important pharmacological targets(1). They transmit their signals to the cell interior by interacting with G proteins. However, it is unclear how receptors and G proteins meet, interact and couple. Here we analyse the concerted motion of G-protein-coupled receptors and G proteins on the plasma membrane and provide a quantitative model that reveals the key factors that underlie the high spatiotemporal complexity of their interactions. Using two-colour, single-molecule imaging we visualize interactions between individual receptors and G proteins at the surface of living cells. Under basal conditions, receptors and G proteins form activity-dependent complexes that last for around one second. Agonists specifically regulate the kinetics of receptor-G protein interactions, mainly by increasing their association rate. We find hot spots on the plasma membrane, at least partially defined by the cytoskeleton and clathrin-coated pits, in which receptors and G proteins are confined and preferentially couple. Imaging with the nanobody Nb37 suggests that signalling by G-protein-coupled receptors occurs preferentially at these hot spots. These findings shed new light on the dynamic interactions that control G-protein-coupled receptor signalling.