Canonically, G-protein-coupled receptor (GPCR) signaling is transient and confined to the plasma membrane (PM). Deviating from this paradigm, the parathyroid hormone receptor (PTHR1) stimulates sustained G_s signaling at endosomes. In addition to G_s, PTHR1 activates G_q signaling; yet, in contrast to the PTHR1-G_s pathway, the spatiotemporal dynamics of the G_q branch of PTHR1 signaling and its relationship to G_s signaling remain largely ill defined. Recognizing that a downstream consequence of G_q signaling is the activation of phospholipase D (PLD) enzymes, we leverage activity-based, bioorthogonal imaging tools for PLD signaling to visualize and quantify the G_q branch of PTHR1 signaling. We establish that PTHR1-G_q signaling is short lived, exclusively at the PM, and antagonized by PTHR1 endocytosis. Our data support a model wherein G_q and G_s compete for ligand-bound receptors at the PM and more broadly highlight the utility of bioorthogonal tools for imaging PLDs as probes to visualize GPCR-G_q signaling.

典型地，G 蛋白偶联受体 (GPCR) 信号转导是短暂的并且局限于质膜 (PM)。与此范例不同的是，甲状旁腺激素受体 (PTHR1) 会刺激核内体持续_的Gs信号传导。除了 G _s之外，PTHR1 还激活 G _q信号；然而，与 PTHR1-G _s通路相比，PTHR1 信号转导的 G _q分支的时空动力学及其与 G _s信号转导的关系在很大程度上仍未明确定义。认识到 G _{q的下游后果}信号是磷脂酶 D (PLD) 酶的激活，我们利用基于活性的生物正交成像工具进行 PLD 信号，以可视化和量化 PTHR1 信号的 G _q分支。我们确定 PTHR1-G _q信号是短暂的，仅在 PM 存在，并被 PTHR1 内吞作用所拮抗。我们的数据支持一个模型，其中 G _q和 G _s在 PM 竞争配体结合受体，并更广泛地强调生物正交工具用于成像 PLD 作为探针以可视化 GPCR-G _q信号的效用。