Crystal structures of free and antagonist-bound states of human α9 nicotinic receptor extracellular domain

Marios Zouridakis; Petros Giastas; Eleftherios Zarkadas; Dafni Chroni-Tzartou; Piotr Bregestovski; Socrates J Tzartos

doi:10.1038/nsmb.2900

Crystal structures of free and antagonist-bound states of human α9 nicotinic receptor extracellular domain

Nat Struct Mol Biol. 2014 Nov;21(11):976-80. doi: 10.1038/nsmb.2900. Epub 2014 Oct 5.

Authors

Marios Zouridakis¹, Petros Giastas¹, Eleftherios Zarkadas², Dafni Chroni-Tzartou¹, Piotr Bregestovski³, Socrates J Tzartos²

Affiliations

¹ Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece.
² 1] Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece. [2] Department of Pharmacy, University of Patras, Rio, Greece.
³ INSERM UMR1106, Brain Dynamics Institute, University Aix-Marseille, Marseille, France.

PMID: 25282151
DOI: 10.1038/nsmb.2900

Abstract

We determined the X-ray crystal structures of the extracellular domain (ECD) of the monomeric state of human neuronal α9 nicotinic acetylcholine receptor (nAChR) and of its complexes with the antagonists methyllycaconitine and α-bungarotoxin at resolutions of 1.8 Å, 1.7 Å and 2.7 Å, respectively. The structure of the monomeric α9 ECD superimposed well with the structures of homologous proteins in pentameric assemblies, denoting native folding, despite the absence of a complementary subunit and transmembrane domain. The interaction motifs of both antagonists were similar to those in the complexes with homologous pentameric proteins, thus highlighting the major contribution of the principal side of α9 ECD to their binding. The structures revealed a functionally important β7-β10 strand interaction in α9-containing nAChRs, involving their unique Thr147, a hydration pocket similar to that of mouse α1 ECD and a membrane-facing network coordinated by the invariant Arg210.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acetylcholine / pharmacology
Aconitine / analogs & derivatives*
Aconitine / chemistry
Aconitine / metabolism
Action Potentials / drug effects
Animals
Bungarotoxins / chemistry*
Bungarotoxins / metabolism
Crystallography, X-Ray
Gene Expression
Humans
Models, Molecular
Mutation
Nicotine / pharmacology
Oocytes / cytology
Oocytes / drug effects
Oocytes / metabolism
Patch-Clamp Techniques
Pichia / genetics
Pichia / metabolism
Protein Binding
Protein Interaction Domains and Motifs*
Protein Structure, Secondary
RNA, Complementary / genetics
RNA, Complementary / metabolism
Receptors, Nicotinic / chemistry*
Receptors, Nicotinic / genetics
Receptors, Nicotinic / metabolism
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Xenopus laevis

Substances

Bungarotoxins
RNA, Complementary
Receptors, Nicotinic
Recombinant Proteins
nAChR alpha9
methyllycaconitine
Nicotine
Acetylcholine
Aconitine

Associated data

PDB/4D01
PDB/4UXU
PDB/4UY2