Structure of the agonist 12\u2013HHT in its BLT2 receptor-bound state

Fabrice Giusti,Jutta Rieger,Marjorie Damian,Alexandre Pozza,Christel Le Bon,Marina Casiraghi,Karine Moncoq,Jean-Louis Banères,Elodie Point,Laurent J Catoire

doi:10.1038/s41598-020-59571-6

Abstract

G Protein-Coupled receptors represent the main communicating pathway for signals from the outside to the inside of most of eukaryotic cells. They define the largest family of integral membrane receptors at the surface of the cells and constitute the main target of the current drugs on the market. The low affinity leukotriene receptor BLT2 is a receptor involved in pro- and anti-inflammatory pathways and can be activated by various unsaturated fatty acid compounds. We present here the NMR structure of the agonist 12–HHT in its BLT2-bound state and a model of interaction of the ligand with the receptor based on a conformational homology modeling associated with docking simulations. Put into perspective with the data obtained with leukotriene B4, our results illuminate the ligand selectivity of BLT2 and may help define new molecules to modulate the activity of this receptor.

Highlights

G Protein-Coupled receptors represent the main communicating pathway for signals from the outside to the inside of most of eukaryotic cells
The NMR structure of 12–HHT is based on the detection of dipolar interactions in the ligand through two-dimensional homonuclear 1H Nuclear Overhauser Effect SpectroscopY (NOESY) experiments[67]
BLT2 was designated as the low-affinity leukotriene B4 (LTB4) receptor, in contrast to BLT1, with in cellulo Kd of ~20 nM compared with ~1 nM for BLT130

Summary

Introduction

G Protein-Coupled receptors represent the main communicating pathway for signals from the outside to the inside of most of eukaryotic cells. G protein-coupled receptors (GPCRs) are integral membrane proteins that allow the signal transduction from the outside to the inside of most of eukaryotic cells[1] These receptors consist in a large family of proteins whose activities can be related to various ligands, from small organic compounds like neurotransmitters or hormones, to lipids, peptides or proteins. The leukotriene receptors 126 (BLT1) and 227–30 (BLT2) are cell surface GPCRs that share 45% amino acid sequence identity in human and are involved in pro- and anti-inflammatory pathways[31,32,33,34] They were initially named high (BLT1) and low leukotriene B4 (LTB4) (BLT2) receptors as the equilibrium dissociation constant (Kd) values of LTB4 in the presence of membrane fractions transfected by either BLT1 or BLT2 is 20-fold weaker in the case of BLT2 compared to BLT1 transfected HEK 293 cells In membrane fractions of Chinese Hamster Ovary cells (CHO) transfected by BLT2, the half maximal inhibitory concentration (IC50) and the half maximal effective concentration (EC50)

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Conclusion