The adhesion G-protein-coupled receptor (GPCR) latrophilin 3 (ADGRL3) has been associated with increased risk of attention deficit hyperactivity disorder (ADHD) and substance use in human genetic studies. Knockdown in multiple species leads to hyperlocomotion and altered dopamine signaling. Thus, ADGRL3 is a potential target for treatment of neuropsychiatric disorders that involve dopamine dysfunction, but its basic signaling properties are poorly understood. Identification of adhesion GPCR signaling partners has been limited by a lack of tools to acutely activate these receptors in living cells. Here, we design a novel acute activation strategy to characterize ADGRL3 signaling by engineering a receptor construct in which we could trigger acute activation enzymatically. Using this assay, we found that ADGRL3 signals through G12/G13 and Gq, with G12/13 the most robustly activated. Gα_12/13 is a new player in ADGRL3 biology, opening up unexplored roles for ADGRL3 in the brain. Our methodological advancements should be broadly useful in adhesion GPCR research.

在人类遗传学研究中，粘附 G 蛋白偶联受体 (GPCR) latrophilin 3 (ADGRL3) 与注意力缺陷多动障碍 (ADHD) 和药物滥用的风险增加有关。多个物种的基因敲低会导致过度运动和多巴胺信号传导改变。因此，ADGRL3 是治疗涉及多巴胺功能障碍的神经精神疾病的潜在靶点，但其基本信号传导特性尚不清楚。由于缺乏快速激活活细胞中这些受体的工具，粘附 GPCR 信号传导伴侣的识别受到限制。在这里，我们设计了一种新的急性激活策略，通过设计受体构建体来表征 ADGRL3 信号传导，在该受体构建体中我们可以通过酶促触发急性激活。使用该测定，我们发现 ADGRL3 通过 G12/G13 和 Gq 发出信号，其中 G12/13 激活最强烈。Gα _12/13是 ADGRL3 生物学的新参与者，开启了 ADGRL3 在大脑中尚未探索的作用。我们的方法学进步应该广泛用于粘附 GPCR 研究。