Exploring human rare disease variants from a multidimensional perspective illuminates receptor - G protein coupling diversity

Abstract

G protein-coupled receptors (GPCRs) are transmembrane proteins capable of detecting signals as diverse as odours, neurotransmitters, and hormones. Upon activation, receptor signalling converges onto four G protein subtypes to regulate intracellular responses. Therefore, variation in a single G protein gene can potentially impact the function of numerous receptors. In this work, we have performed a multidimensional study of rare disease mutations in Gs, a prototypical G protein. By integrating data from 3D structures, GPCR / G protein functional pairings, transcriptomics, biophysics, and molecular dynamics with systems pharmacology modelling, our results reveal why mutations impairing receptor / Gs coupling result in highly specific context-based signalling defects. Furthermore, we show that mutations leading to the same rare disease can alter different signal transduction steps, highlighting the importance of patient-specific treatment strategies. By closely dissecting G protein coupling, our study provides a blueprint to interrogate GPCR pathway signalling diversity in different (patho)physiological contexts.