Structural basis of neuropeptide Y signaling through Y1 receptor

Chaehee Park,Sang Ah Kim,Hyeonuk Woo,Jinuk Kim,Injin Bang,Seung-Bum Ko,Yeol Kyo Choi,Wonpil Im,Chaok Seok,Hyeongseop Jeong,Tae-Young Yoon,Hyunook Kang,Hee-Jung Choi

doi:10.1038/s41467-022-28510-6

Abstract

Neuropeptide Y (NPY) is highly abundant in the brain and involved in various physiological processes related to food intake and anxiety, as well as human diseases such as obesity and cancer. However, the molecular details of the interactions between NPY and its receptors are poorly understood. Here, we report a cryo-electron microscopy structure of the NPY-bound neuropeptide Y1 receptor (Y1R) in complex with Gi1 protein. The NPY C-terminal segment forming the extended conformation binds deep into the Y1R transmembrane core, where the amidated C-terminal residue Y36 of NPY is located at the base of the ligand-binding pocket. Furthermore, the helical region and two N-terminal residues of NPY interact with Y1R extracellular loops, contributing to the high affinity of NPY for Y1R. The structural analysis of NPY-bound Y1R and mutagenesis studies provide molecular insights into the activation mechanism of Y1R upon NPY binding.

Highlights

Neuropeptide Y (NPY) is highly abundant in the brain and involved in various physiological processes related to food intake and anxiety, as well as human diseases such as obesity and cancer
The published antagonist-bound crystal structure of Y1 receptor (Y1R) was solved using a modified construct involving thermostabilizing mutation, C-terminal truncation, and replacement of intracellular loop 3 (ICL3) with T4 lysozyme[10]
Before purifying the NPY–Y1R–Gi1 complex, we confirmed the functionality of the synthesized NPY by performing bioluminescence resonance energy transfer (BRET) assays, which showed that Y1R recruited Gi1 in response to NPY binding (Supplementary Fig. 1)

Summary

Introduction

Neuropeptide Y (NPY) is highly abundant in the brain and involved in various physiological processes related to food intake and anxiety, as well as human diseases such as obesity and cancer. 1234567890():,; The human neuropeptide Y (NPY) system comprises three peptide ligands, NPY, peptide YY (PYY), and pancreatic polypeptide (PP), and four functional NPY receptors Y1R, Y2R, Y4R, and Y5R1 These endogenous peptide ligands consisting of 36 amino acids with the amidated C-terminus activate specific NPY receptors generally coupled to Gi or Go protein[2]. Of these three peptide ligands, NPY, a highly abundant peptide ligand in the brain, can activate all four subtypes of the NPY receptor and is involved in various physiological processes such as food intake, stress response, anxiety, and memory retention[3,4,5]. These structures provide molecular details of Y1R-selective antagonist binding and the overall architecture of an inactive state of Y1R, the molecular mechanism of its activation by binding of the endogenous agonist NPY is still unknown

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Conclusion