Fillion Dany, Devost Dominic, Hébert Terence E
Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada.
Methods Mol Biol. 2019;1957:83-91. doi: 10.1007/978-1-4939-9158-7_5.
Initially identified as monomers, G protein-coupled receptors (GPCRs) can also form functional dimers that act as distinct signalling hubs for the integration of cellular signalling. We previously found that the angiotensin II (Ang II) type 1 receptor (AT1R) and the prostaglandin F2α (PGF2α) receptor (FP), both important in the control of smooth muscle contractility, form such a functional heterodimeric complex in HEK 293 and vascular smooth muscle cells (Goupil et al., J Biol Chem 290:3137-3148, 2015; Sleno et al., J Biol Chem 292:12139-12152, 2017). In addition to canonical G protein coupling, GPCRs recruit and engage β-arrestin-dependent pathways. Using BRET-based biosensors, we demonstrate how to assess recruitment of β-arrestin-1 and -2 to AT1R and the AT1R/FP dimer in response to Ang II. Surprisingly, β-arrestin-1 and -2 were recruited to the dimer, in response to PGF2α as well, even though FP alone cannot recruit either β-arrestin-1 and -2.
G蛋白偶联受体（GPCRs）最初被鉴定为单体，但也能形成功能性二聚体，作为细胞信号整合的独特信号枢纽。我们之前发现，对平滑肌收缩控制很重要的血管紧张素II（Ang II）1型受体（AT1R）和前列腺素F2α（PGF2α）受体（FP），在HEK 293细胞和血管平滑肌细胞中形成了这样一种功能性异源二聚体复合物（Goupil等人，《生物化学杂志》290:3137 - 3148，2015；Sleno等人，《生物化学杂志》292:12139 - 12152，2017）。除了经典的G蛋白偶联外，GPCRs还招募并参与β - 抑制蛋白依赖性途径。使用基于生物发光共振能量转移（BRET）的生物传感器，我们展示了如何评估β - 抑制蛋白 - 1和 - 2对Ang II响应时向AT1R和AT1R/FP二聚体的募集情况。令人惊讶的是，即使单独的FP不能募集β - 抑制蛋白 - 1和 - 2，但响应PGF2α时，β - 抑制蛋白 - 1和 - 2也会被募集到二聚体上。
