Designer receptors exclusively activated by designer drugs (DREADDs) are chemogenetic tools for remotely controlling cellular signaling, neural activity, behavior, and physiology. Using a structure-guided approach, we provide a peripherally restricted Gi-DREADD, hydroxycarboxylic acid receptor DREADD (HCAD), whose native receptor is minimally expressed in the brain, and a chemical actuator that does not cross the blood-brain barrier (BBB). This was accomplished by combined mutagenesis, analoging via an ultra-large make-on-demand library, structural determination of the designed DREADD receptor via cryoelectron microscopy (cryo-EM), and validation of HCAD function. Expression and activation of HCAD in dorsal root ganglion (DRG) neurons inhibit action potential (AP) firing and reduce both acute and tissue-injury-induced inflammatory pain. The HCAD chemogenetic system expands the possibilities for studying numerous peripheral systems with little adverse effects on the central nervous system (CNS). The structure-guided approach used to generate HCAD also has the potential to accelerate the development of emerging chemogenetic tools for basic and translational sciences.

中文翻译：

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外周限制性化学遗传学系统的结构引导设计


专门由设计药物 （DREADD） 激活的设计受体是远程控制细胞信号传导、神经活动、行为和生理学的化学遗传学工具。使用结构引导方法，我们提供了一种外周限制性 Gi-DREADD、羟基羧酸受体 DREADD （HCAD），其天然受体在大脑中表达最少，以及一种不穿过血脑屏障 （BBB） 的化学致动器。这是通过联合诱变、通过超大型按需构建文库进行模拟、通过冷冻电子显微镜 （cryo-EM） 对设计的 DREADD 受体进行结构测定以及验证 HCAD 功能来实现的。HCAD 在背根神经节 （DRG） 神经元中的表达和激活抑制动作电位 （AP） 放电并减少急性和组织损伤诱导的炎症性疼痛。HCAD 化学遗传学系统扩展了研究许多外周系统的可能性，对中枢神经系统 （CNS） 几乎没有不利影响。用于生成 HCAD 的结构引导方法也有可能加速用于基础科学和转化科学的新兴化学遗传学工具的开发。