Manglik Aashish, Kobilka Brian K, Steyaert Jan
Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305; email:
Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium; email:
Annu Rev Pharmacol Toxicol. 2017 Jan 6;57:19-37. doi: 10.1146/annurev-pharmtox-010716-104710. Epub 2016 Dec 7.
Ligand-induced activation of G protein-coupled receptors (GPCRs) is a key mechanism permitting communication between cells and organs. Enormous progress has recently elucidated the structural and dynamic features of GPCR transmembrane signaling. Nanobodies, the recombinant antigen-binding fragments of camelid heavy-chain-only antibodies, have emerged as important research tools to lock GPCRs in particular conformational states. Active-state stabilizing nanobodies have elucidated several agonist-bound structures of hormone-activated GPCRs and have provided insight into the dynamic character of receptors. Nanobodies have also been used to stabilize transient GPCR transmembrane signaling complexes, yielding the first structural insights into GPCR signal transduction across the cellular membrane. Beyond their in vitro uses, nanobodies have served as conformational biosensors in living systems and have provided novel ways to modulate GPCR function. Here, we highlight several examples of how nanobodies have enabled the study of GPCR function and give insights into potential future uses of these important tools.
配体诱导的G蛋白偶联受体（GPCRs）激活是细胞与器官之间进行通讯的关键机制。最近取得的巨大进展阐明了GPCR跨膜信号传导的结构和动态特征。纳米抗体是骆驼科仅重链抗体的重组抗原结合片段，已成为将GPCR锁定在特定构象状态的重要研究工具。活性状态稳定纳米抗体阐明了激素激活的GPCRs的几种激动剂结合结构，并提供了对受体动态特征的深入了解。纳米抗体还被用于稳定瞬时GPCR跨膜信号复合物，首次对GPCR跨细胞膜的信号转导提供了结构上的见解。除了在体外的应用，纳米抗体还作为活系统中的构象生物传感器，并提供了调节GPCR功能的新方法。在这里，我们重点介绍几个纳米抗体如何促进GPCR功能研究的例子，并深入探讨这些重要工具未来可能的用途。
