Molecular Mechanisms of G protein-coupled Receptor Biased Signaling

研究总结 G蛋白偶联受体是一个由7种跨膜蛋白组成的重要超家族。 在细胞间的通信中，对感知、运动和思维过程至关重要。很大一部分 目前批准的药物疗法针对的是GPCRs，但受到与 差异信号通路的参与被称为“功能选择性”或“偏向信号”。剥削 有偏向的信号传递代表了一种有希望的方法来设计具有更好的“on-on”的途径选择药物 目标配置文件，但导致有偏见的信号传递的结构层面的机制仍然很差 明白了。有偏见配体识别的结构知识的最新进展导致了 鉴定结合口袋基序，如细胞外环2(EL2)和跨膜(TM)7，很重要 通过直接配基结合进行有偏向的信号转导。使用基于结构的方法，我的实验室 旨在使用各种化学、生物学和生物物理方法来揭示 管理有偏见的信号的捆绑口袋。战略将结合结构指导的 突变、邻位/变构偏向配体、G蛋白功能的动力学监测和β-arrestin 利用荧光素酶和生物发光共振能量转移(BRET)技术进行招募，以及结构- 功能选择性关系(SFSR)到最终涉及的关键GPCR结合基序 效应器切换。这种方法关注的是有结构知识和G蛋白的关键受体 和β-arrestin偏向配体可用。通过这些研究，全面地从机理上理解 偏向GPCR的信号转导将引导研究人员走向新一代优越的治疗方法。 1

Research Summary G protein-coupled receptors (GPCRs) are an important superfamily of seven transmembrane proteins involved in cell-to-cell communication essential for sensing, movement, and thought processes. A significant portion of current approved drug therapies target GPCRs, but suffer from “on-target” side-effects related to the engagement of differential signaling pathways known as “functional selectivity” or “biased signaling.” Exploiting biased signaling represents a promising approach toward designing pathway-selective drugs with better “on- target” profiles, but the mechanisms at the structural level that lead to biased signaling are still poorly understood. Recent advancement in structural knowledge of biased ligand recognition has led to the identification of binding pocket motifs, such as extracellular loop 2 (EL2) and transmembrane (TM) 7, important for `switching' biased signaling via direct ligand engagement. Using a structure-based approach, my laboratory aims to use a variety of chemical biology and biophysical approaches to uncover common mechanisms within the binding pocket that govern biased signaling. Strategies will incorporate a combination of structure-guided mutagenesis, orthosteric/allosteric biased ligands, kinetic monitoring of G protein function and β-arrestin recruitment using luciferase and bioluminescent resonance energy transfer (BRET) techniques, and structure- `functional selectivity' relationships (SFSRs) to ultimately to pin-point key GPCR binding motifs involved in effector switching. This approach focuses on key receptors where there is structural knowledge and G protein and β-arrestin-biased ligands available. Through these studies, a comprehensive mechanistic understanding into GPCR biased signaling will guide researchers toward a new generation of superior therapeutics. 1