Mechanistic insights from the atomic-level quaternary structure of short-lived GPCR oligomers of the human secretin receptor in live cells
Year: 2025
Type: article
Abstract: The functional significance of the interactions between proteins in living cells to form short-lived quaternary structures cannot be overemphasized. Yet, quaternary structure information is not captured by current methods, neither can those methods determine structure within living cells. The dynamic versatility, abundance, and functional diversity of G protein-coupled receptors (GPCRs) pose myriad challenges to existing technologies but also present these proteins as the ideal testbed for new technologies to investigate the complex inter-regulation of receptor-ligand, receptor-receptor, and receptor-downstream effector interfaces in living cells. Here, we present development and use of a novel method capable of overcoming existing challenges by combining distributions (or spectrograms) of FRET efficiencies from populations of fluorescently tagged proteins associating into oligomeric complexes in live cells with diffusion-like trajectories of FRET donors and acceptors obtained from molecular dynamics (MD) simulations. Our approach provides an atom-level picture of the binding interfaces within oligomers of the human secretin receptor (hSecR) in live cells and allows for extraction of mechanistic insights into the function of GPCRs oligomerization. This FRET-MD spectrometry approach is a robust platform for investigating protein-protein binding mechanisms and opens a new avenue for investigating stable as well as fleeting quaternary structures of any membrane proteins in living cells.
Source: Communications Biology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $4,190
Awards: MRI: Development of a Multimodal Instrument for Simultaneous Mechanical and Fluorescence Spectroscopy Measurements of Single Molecules and Molecular Aggregates, CAREER: Mechanical unfolding and refolding of multidomain proteins as a new signaling mechanism, studied using a novel single molecule approach, IIBR Research Methods: Probing the structure, abundance, dynamics, and function of protein complexes within their cellular environment, G5516638976, Molecular basis of activation of the prototypic class B G protein-coupled secretin receptor, MRI: Development of an Advanced Two-Photon Microscope for Five-Dimensional Imaging of Macromolecular Systems in Living Cells
OpenAlex ID: W4411857883