Molecular determinants for agonist recognition and discrimination in P2X2 receptors

TY - JOUR

T1 - Molecular determinants for agonist recognition and discrimination in P2X2 receptors

AU - Gasparri, Federica

AU - Wengel, Jesper

AU - Grutter, Thomas

AU - Pless, Stephan A

N1 - © 2019 Gasparri et al.

PY - 2019/7/1

Y1 - 2019/7/1

N2 - P2X receptors (P2XRs) are trimeric ligand-gated ion channels that open a cation-selective pore in response to ATP binding. P2XRs contribute to synaptic transmission and are involved in pain and inflammation, thus representing valuable drug targets. Recent crystal structures have confirmed the findings of previous studies with regards to the amino acid chains involved in ligand recognition, but they have also suggested that backbone carbonyl atoms contribute to ATP recognition and discrimination. Here we use a combination of site-directed mutagenesis, amide-to-ester substitutions, and a range of ATP analogues with subtle alterations to either base or sugar component to investigate the contributions of backbone carbonyl atoms toward ligand recognition and discrimination in rat P2X2Rs. Our findings demonstrate that while the Lys69 backbone carbonyl makes an important contribution to ligand recognition, the discrimination between different ligands is mediated by both the side chain and the backbone carbonyl oxygen of Thr184. Together, our data demonstrate how conserved elements in P2X2Rs recognize and discriminate agonists.

AB - P2X receptors (P2XRs) are trimeric ligand-gated ion channels that open a cation-selective pore in response to ATP binding. P2XRs contribute to synaptic transmission and are involved in pain and inflammation, thus representing valuable drug targets. Recent crystal structures have confirmed the findings of previous studies with regards to the amino acid chains involved in ligand recognition, but they have also suggested that backbone carbonyl atoms contribute to ATP recognition and discrimination. Here we use a combination of site-directed mutagenesis, amide-to-ester substitutions, and a range of ATP analogues with subtle alterations to either base or sugar component to investigate the contributions of backbone carbonyl atoms toward ligand recognition and discrimination in rat P2X2Rs. Our findings demonstrate that while the Lys69 backbone carbonyl makes an important contribution to ligand recognition, the discrimination between different ligands is mediated by both the side chain and the backbone carbonyl oxygen of Thr184. Together, our data demonstrate how conserved elements in P2X2Rs recognize and discriminate agonists.

U2 - 10.1085/jgp.201912347

DO - 10.1085/jgp.201912347

M3 - Journal article

C2 - 31126967

SN - 0022-1295

JO - Journal of General Physiology

JF - Journal of General Physiology

ER -